SET - Production Processes and Efficiency Measures

SET - Production Processes and Efficiency Measures

Overview of textile production processes and energy efficiency measures for machineries,

technologies and equipment researched on by the SET project team to develop an Energy

Saving and Efficiency Tool (ESET)

Leading author: CITEVE

Date: December 2014

Table of contents

Table of contents .................................................................................................................... 2

Acknowledgments .................................................................................................................. 3

1 – Executive summary ......................................................................................................... 4

2 - Introduction ....................................................................................................................... 5

3 - Textile production processes ....................................................................................... 7

4 - Energy in the textile industry.................................................................................... 11

4.1 - Energy use in yarn production, main factors affecting energy consumption and

reference values ...................................................................................................................... 12

4.2 - Energy use in fabric production, main factors affecting energy consumption and

reference values ...................................................................................................................... 14

4.3 - Energy use in finishing, main factors affecting energy consumption and reference

values ...................................................................................................................................... 16

5 - Energy efficiency measures ....................................................................................... 21

5.1 - Energy efficiency measures for Yarn Production process ............................................... 23

5.2 - Energy efficiency measures for Fabric Production process ............................................ 26

5.3 - Energy efficiency measures for Finishing process........................................................... 28

5.4 - Cross-cutting energy efficiency measures ...................................................................... 44

6 – Conclusions and Next Steps ....................................................................................... 72

7 - Reference .......................................................................................................................... 73

SET – Production Processes and Efficiency Measures

www.euratex.eu/set 3/73

Disclaimer The sole responsibility for the content of this publication lies with the authors. It does not

necessarily reflect the opinion of the European Union or of any of the organization

mentionedunless explicitly stated. Neither the EASME nor the European Commission are

responsible for any use that may be made of the information contained therein.

This document is updated until December 2014, however contents are simplifield and

provided for general information purposes only. By no mean the contents provided in this

document shall be considred exausitve.

Legal and or official documentation released at EU level or the national legislation shall be

consulted.

Acknowledgments

The SET project (contract n° IEE/13/557/SI2.675575) is co-funded by the IEE Intelligent Energy

Europe programme of the European Union managed by EASME, the European Commission

executive agency for SMEs.

http://www.euratex.eu/set


1 – Executive summary

This document is the report of the work performed by the SET project team coordinated

by CITEVE for the purpose of 1) defining and structure the targeted basic textile

production processes, 2) collecting energy efficiency measures for machineries,

technologies and equipment, and 3) identify newly developed processes with potential to

replace traditional ones with gains in energy consumption.

Three levels of textile processes classification were defined. The first level corresponds to

the three value creation steps defined early in the project – Spinning (later replaced by

Yarn Production), Fabric Production and Finishing. The second level (phase) provides

more specific processes or steps inside the three main groups and in the third level (sub-

phase) are listed the most significant machineries, equipments or very specific processes,

in terms of energy use.

A list of 117 cross-cutting measures and 105 specific energy efficiency measures were

created, mostly based on Hasenbeigi [1](specific measures) and ARTISAN project (cross

cutting measures). This is far above the targeted 60 specific and 60 cross cutting. Each of

the identified specific measure was linked to a process or machinery listed on the second

or third level of process classification, respectively.

Newly developed processes can be found as measures for energy savings in Energy

Efficiency Measures chapter (e.g. Microwave Dyeing).

For the collection of these measures, teams were defined as in the following table:

Table 1 – Composition of the SET project teams collecting energy efficiency measures

Team Type of measures Process Organizations

1 Specific Yarn production DITF (DE) / IVGT (DE) / Centexbel (BE)

2 Specific Fabric production TMTE (HU)/ IVGT (DE)

3 Specific Finishing CITEVE (PT) / IVGT (DE)/ Inotex – ATOK (CZ)

4 Cross cutting ENEA (IT)


2 - Introduction

The need of reduce / rationalize energy consumption has assumed huge importance

during the last years with the growth of energy prices, environmental constraints and, in

some countries, legal obligations.

The rational use of energy calls for a broad application of energy efficiency technologies in

the various industrial sectors where energy is wasted. One of these energy intensive

industrial sectors to be considered to improve efficiency through the introduction of

energy conservation technologies and techniques is the textile industry.

Over the past decade there has been a decrease in the energy consumption of this industry

in the European Union (figure 1), which is mainly due to the economic situation but also

some improvements in energy efficiency. However, there is still room for further

improvements since the situation varies significantly within the EU members.

Figure 1– Energy consumption on Textile and Leather industries in EU (Source: Eurostat 29/10/2014)

The representation of energy costs, compared to the total costs of the company, in the case

of a vertical textile company, based in a study in Portugal, is estimated to be between 15%

to 25% [2]. Developing an understanding of how energy is used in a textiles plant is an

important component of improving the energy management. Knowing what the major

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end-users of energy in a plant are helps to identify what priorities need to be for energy

efficiency improvements.

Energy-efficiency improvement opportunities in the textile industry include opportunities

for process specific improvements, which includes retrofit/process optimization as well as

the complete replacement of the current machinery with state-of-the-art new technology,

and opportunities for cross cutting improvements in steam and/or thermal fluid boilers,

compressed air, conditioning, lighting, electrical motors and pumps, etc.


3 - Textile production processes

The textile industry is one of the most complex industrial chains in the manufacturing

industry because of the wide variety of textile products, substrates, processes, machinery

and components used, and finishing steps undertaken. Different types of fibers, methods

of yarn and fabric production, and finishing processes combinations (preparation,

printing, dyeing, chemical/mechanical finishing, etc), all interrelate in producing a finished

fabric. The combination of processes and process parameters is almost infinite and has a

considerable influence on energy efficiency.

Before collecting energy efficiency measures it was fundamental to develop a description

of the processes to be used on this project, from the huge variety available, to represent

the textile industry, taking mainly into account the energy consumption.

First, the major textile processes were defined for a first level of classification:

• Yarn production1

• Fabric Production

• Finishing

Within these main processes, two more specific levels of classification of processes used

on the textile industry were defined - second level of classification or phase and third level

of classification or subphase. This classification was based on ITMA 2015 Index of

Products [3], which is recognized and accepted by the textile sector.

The following tables represent the classification of textiles processes in the three different

levels to be considered in the next steps of this project and the associated hierarchical

identification.

Table 2 - Description of processes and equipments for Yarn Production

1 The expression “Yarn production” has replaced the original term “Spinning” in the first level of

classification in order to avoid repetition of terms in different levels, since “Spinning” was also being used in the second level of classification.


Process (Level 1)

Phase (Level 2)

Subphase (Level 3)

Yarn production (1)

Spinning Preparation for

cotton fibers (1.1)

Opening for cotton (1.1.1)

Cards (1.1.2)

Drawing machines for cotton (1.1.3)

Lap winders (1.1.4)

Combing machines for cotton (1.1.5)

Roving frames (1.1.6)

Spinning Preparation for wool

fibers (1.2)

Opening lines for raw wool (1.2.1)

Raw wool scouring lines (1.2.2)

Carbonising lines (1.2.3)

Opening for wool (1.2.4)

Worsted cards (1.2.5)

Semi-worsted cards (1.2.6)

Woollen cards (1.2.7)

Drawing machines for wool (1.2.8)

Combing machines for wool (1.2.9)

Back washing machines (1.2.10)

Finishers (1.2.11)

Roving frames for worsted yarn (1.2.12)

Production of man-made

filaments and fibres (1.3)

Extruders (1.3.1)

Winding (1.3.2)

Spinning (1.4)

Ring-spinning (1.4.1)

Compact spinning (1.4.2)

Rotor spinning (1.4.3)

Air-jet spinning (1.4.4)

Other Spinning machines (1.4.5)

Winding, reeling and covering

(1.5)

Winding machines (1.5.1)

Reeling machines (1.5.2)

Covering machines (1.5.3)

Yarn steaming, setting,

moistening and coating (1.6)

Autoclaves for steaming (1.6.1)

Heat-setting machines (1.6.2)

Moistening machines (1.6.3)

Yarn coating machines (1.6.4)

Texturing, bulking and

crimping (1.7)

Texturing machines (1.7.1)

Bulking and crimping machines (1.7.2)

Doubling and twisting (1.8) Doubling machines (1.8.1)

Twisting machines (1.8.2)


Table 3 - Description of processes and equipments for Fabric Production

Process (Level 1)

Phase (Level 2)

Subphase (Level 3)

Fabric production (2)

Weaving preparation (2.1)

Sectional warping (2.1.1)

Beam warping (2.1.2)

Draw-warping (2.1.3)

Beaming machines (2.1.4)

Sizing/slashing (2.1.5)

Indigo warp dyeing lines (2.1.6)

Weaving (2.2)

Rapier weaving (2.2.1)

Projectile weaving (2.2.2)

Air jet weaving (2.2.3)

Water jet weaving (2.2.4)

Shuttle looms (2.2.5)

Circular weaving (2.2.6)

Narrow fabrics weaving (2.2.7)

Preparation for knitting (2.3) Beam warping (2.3.1)


Knitting (2.4)

Circular knitting machines (2.4.1)

Flat knitting machines (2.4.2)

Warp knitting machines (2.4.3)

Knitting machines for special purposes (2.4.4)


Table 4 - Description of processes and equipments for Finishing

Process (Level 1)

Phase (Level 2)

Subphase (Level 3)

Finishing (3)

Pretreatment (3.1)

Carbonising (3.1.1)

Singeing (3.1.2)

Crabbing (3.1.3)

Desizing (3.1.4)

Bleaching batch (3.1.5)

Continuous Bleaching (3.1.6)

Yarn washing (3.1.7)

Rope washing (3.1.8)

Open-width washing (3.1.9)

Solvent washing (3.1.10)

Milling/fulling (3.1.11)

Yarn Mercerising (3.1.12)

Fabric Mercerising (3.1.13)

Dyeing (3.2)

Yarn continuous dyeing (3.2.1)

Fabric continuous dyeing (3.2.2)

Autoclaves (3.2.3)

Hank (3.2.4)

Jet (3.2.5)

Overflow (3.2.6)

Winch becks (3.2.7)

Jiggers (3.2.8)

Other dyeing machines (3.2.9)

Water extraction and drying (3.3)

Centrifugal hydro-extractors (3.3.1)

Stenter (3.3.2)

Yarn Dryers (3.3.3)

Fabric Dryers (3.3.4)

Other Dryers (3.3.5)

Tumblers (3.3.6)

Finishing machines (3.4)

Mechanical finishing (3.4.1)

Decatising (3.4.2)

Calenders (3.4.3)

Singeing machines (3.4.4)

Knitwear ironing presses (3.4.5)

Tumblers (3.4.6)

Sanfor (3.4.7)

Other finishing machines (3.4.8)

Printing (3.5)

Top and yarn printing (3.5.1)

Flat screen printing (3.5.2)

Rotary screen printing (3.5.3)

Inkjet Printing (3.5.4)

Other printing machines (3.5.5)


4 - Energy in the textile industry

In general, energy in the textile industry is mostly used in the forms of: electricity, as a

common power source for machinery, cooling and temperature control systems, lighting,

office equipment, conditioning, etc., and fuels for steam and thermal fluid boilers and

direct fired equipments.

In the next figure is represented a breakdown of energy consumption by type of energy for

the European Union (28 countries) for textile and leather industries in 2012.

Figure 2 - Breakdown of energy consumption by type of energy for the textile and leather industries in the

European Union on 2012 (source: Eurostat 29/10/2014)

Finishing processes have higher energy consumption than the yarn and fabric production.

Most of the energy used on those processes is thermal. Yarn and Fabric production mostly

use electricity as power source of the machines motors.

The following points present a slightly more detailed description of energy consumption

in each of the first level textile production processes: Yarn Production, Fabric Production

Solid Fuels1%

Petroleum8%

Natural Gas46%

Heat5%

Renewables0%

Electricity40%

Waste0%

Share of energy consumption by type in Textile and

Leather industries (EU28)


and Finishing, main variables affecting that consumption and reference values (when

available) for the consumption of each subphase.

4.1 - Energy use in yarn production, main factors affecting

energy consumption and reference values

Electricity is the major type of energy used in spinning plants. As an example, if the

spinning plant just produces raw yarn in a cotton spinning system, and does not dye or

fix the produced yarn, the fuel may just be used to provide steam for the humidification

system in the cold seasons for preheating the fibers before spinning them together [1].

The factors (triggers) which are most affecting the energy consumption for a

determined textile process in yarn production are presented in the following table, as

well as reference values of energy consumption (when available) for the processes

defined in the previous chapter.

Table 5 – Triggers and relevant product groups and benchmarks for Yarn Production

Phase (Level 2)

Subphase (Level 3)

Triggers

Relevant product groups and

benchmarks for relevant trigger-

combinations

Spinning

Preparation for

cotton fibers (1.1)

Opening for cotton

(1.1.1) Speed of machine

Opening of natural fibers and manmade fiber bales

Cards (1.1.2) Speed of machine

Drawing machines for

cotton (1.1.3) Speed of machine

Lap winders (1.1.4) Speed of machine

Combing machines for

cotton (1.1.5) Speed of machine high eveness and tension

Roving frames (1.1.6) Speed of machine, yarn count

Spinning

Preparation for

wool fibers (1.2)

Opening lines for raw

wool (1.2.1) Speed of machine

Raw wool scouring lines


Carbonising lines (1.2.3) Speed of machine, temperature

Opening for wool (1.2.4) Speed of machine


Phase (Level 2)

Subphase (Level 3)

Triggers



combinations Worsted cards (1.2.5) Speed of machine

Semi-worsted cards


Woollen cards (1.2.7) Speed of machine

Spinning

Preparation for

wool fibers (1.2)

Drawing machines for


Combing machines for


Back washing machines

(1.2.10) Speed of machine, temperature

Finishers (1.2.11) Speed of machine, temperature

Roving frames for

worsted yarn (1.2.12) Speed of machine

Production of

man-made

filaments and

fibres (1.3)

Extruders (1.3.1) Speed of machine, temperature, number of nozzles

Winding (1.3.2) Speed of machine

Spinning (1.4)

Ring-spinning (1.4.1) Yarn count, twist factor, Speed of machine

High yarn tension and elongation

Compact spinning

(1.4.2) Yarn count, twist factor, Speed of machine

Smooth yarn surface, fine count

Rotor spinning (1.4.3) Yarn count, twist factor, Speed of machine

Smooth yarn surface,

Air-jet spinning (1.4.4) Yarn count, twist factor, Speed of machine

Special soft yarn with high hairiness, low tension

Other Spinning

machines (1.4.5) Variable, depending on the type of machine

Winding, reeling

and covering (1.5)

Winding machines

(1.5.1) Yarn count, Speed of machine

Reeling machines (1.5.2) Yarn count, Speed of machine

Covering machines


Yarn steaming,

setting,

Autoclaves for steaming

(1.6.1) Speed of machine, type of fibre, temperature

Cotton


Phase (Level 2)

Subphase (Level 3)

Triggers



combinations moistening and

coating (1.6)

Heat-setting machines


Polyester

Moistening machines


Yarn coating machines


Yarns for circular knitting

Texturing,

bulking and

crimping (1.7)

Texturing machines


Bulking and crimping

machines (1.7.2) Speed of machine, type of fibre

Doubling and

twisting (1.8)

Doubling machines


Increase of yarn tension, multi-material mix

Twisting machines

(1.8.2) Yarn count, twist factor, Speed of machine

4.2 - Energy use in fabric production, main factors affecting

energy consumption and reference values

The weaving sector consumes almost only electricity. This sector is a major consumer

of compressed air, particularly when the looms are air jet. The amount of energy

consumed by each loom during its weaving operation can be estimated from the motor

capacity and weaving speed. Across the different weaving technologies, weft insertion

systems consume a large share of the total electricity use of the equipment. Usually,

the lighting has a great weight in terms of electricity consumption, because the

weaving sections have many lighting fixtures installed [5]. On the other hand, some

amount of thermal energy is consumed in sizing, as one of the possible preparatory

operations for weaving.

The energy consumption is not necessarily high for the knitting process. However, of

the main production facilities for this process, knitting machines have also been

undergoing a shift towards high speed and large capacity and fine gauge features; the


current industry trend is for high added-value goods and multi-line, small-volume

production based on advanced systems such as computer-controlled pattern making

mechanisms. Therefore, a potential tendency for increased energy consumption

should be taken into account [6].


determined textile process in fabric production are presented in the following table, as



Table 6 – Triggers and relevant product groups and benchmarks for Fabric Production

Phase (Level 2)

Subphase (Level 3)

Triggers



combinations

Weaving preparation (2.1)


Repeatable patterns in warp direction, multicolor yarns

Clothing, home textiles, technical textiles with patterns

Beam warping (2.1.2) High-speed production for uncolored warps

Draw-warping (2.1.3) PES/PA filament yarns only

Technical textile warp

Beaming machines (2.1.4)

Sizing/slashing (2.1.5) Staple fiber yarns Yarns with a high hairiness, or electrostatic clamping

Indigo warp dyeing lines (2.1.6)

Denim/jeans production only

Weaving (2.2)

Rapier weaving (2.2.1)

Speed in bpm, width,

warp/weft density ,

shading motion or

Jacquard

Different yarn counts and appearance (flame yarn)

Projectile weaving (2.2.2)

Speed in bpm , width ,

warp/weft density ,

shading motion or

Jacquard

Even yarn count and same material


Speed in bpm , width ,

warp/weft density ,

shading motion or

Jacquard

High production and even yarn caracteristic

Water jet weaving (2.2.4)

Yarn material which don’t take-up liquid

Filament yarns, tapes

Shuttle looms (2.2.5) Tubular fabrics Small quantities or specialized yarns


Phase (Level 2)

Subphase (Level 3)

Triggers



combinations

Circular weaving (2.2.6) Tubular fabrics Filtersacks

Narrow fabrics weaving (2.2.7)

Tape and fabrics <30cm

Preparation for knitting (2.3)

Beam warping (2.3.1) For warp knitting only


Repateable patterns

Knitting (2.4)

Circular knitting machines (2.4.1)

Flat knitting machines (2.4.2)

Clothing

Warp knitting machines (2.4.3)

High production, thick yarn diameter, spacer fabrics

Home textiles, technical textiles

Knitting (2.4) Knitting machines for special purposes (2.4.4)

4.3 - Energy use in finishing, main factors affecting energy

consumption and reference values

Finishing is the major energy consumer in the textile industry because it uses a high

amount of thermal energy in the forms of both steam, thermal fluid, heat and gas for

direct fired equipments. The energy used in this process depends on various factors

such as the form of the product being processed (fiber, yarn, fabric), the machine type,

the specific process type, the combinations of processes, the state of the final product,

etc.

A significant share of thermal energy in a dyeing plant is lost through wastewater

discharge, heat released from equipment, exhaust gas loss, idling, evaporation from

liquid surfaces, un-recovered condensate, loss during condensate recovery, and during

product drying (e.g. by over-drying).


determined textile process in fabric production are presented in the following table, as



Table 7 – Triggers and relevant product groups and benchmarks for Finishing


Phase (Level 2)

Subphase (Level 3)

Triggers



combinations

Pretreatment (3.1)

Carbonising (3.1.1) Speed of machine, temperature field

Singeing (3.1.2) Speed of gassing, machine type, type of fiber

Crabbing (3.1.3)

Velocity of machine, specific weight of fabric g/m2, temperature and pressure of the rollers

Pretreatment (3.1)

Desizing (3.1.4)

Liquor Ratio (L.R.) in discontinuous processes, type of fiber, machine type

[1] Desize unit - Desizing - Energy requirement (GJ/tonne output): 1,0 – 3,5


Liquor Ratio (L.R.), type of fiber, machine type

[1] Kier - Scouring/Bleaching - Energy requirement (GJ/tonne output): 6,0 – 7,5 Jig/ winch - Bleaching - Energy requirement (GJ/tonne output): 3,0 – 6,5


Type of fiber, machine type

[1] Open width range - Scouring/bleaching - Energy requirement (GJ/tonne output): 3,0 – 7,0

Yarn washing (3.1.7) Process temperature, type of fiber, machine type

Rope washing (3.1.8) Liquor Ratio (L.R.), Bath temperature, type of fiber, machine type


Phase (Level 2)

Subphase (Level 3)

Triggers



combinations


Process temperature, type of fiber, machine type

[1] 5 hot standing tanks before bleaching – 7,5 GJ/tonne 4 tanks, fully counter flow, with heat exchanger before bleaching- 2,8 GJ/tonne 5 tanks, fully counter flow, with heat exchanger before scouring/bleaching- 3,0 GJ/tonne 4 tanks counter flow and 1 cold standing tank before dyeing – 6,6 GJ/tonne 4 hot counter flow and 3 cold individual flow before printing – 10,5 GJ/tonne 4 hot counter flow with heat exchanger and 3 cold individual flow before printing – 5,5 GJ/tonne

Solvent washing (3.1.10)

Type of machine, velocity of machine, solvent flow rate, drying temperature

Milling/fulling (3.1.11)

Type of fiber, machine type



Pretreatment (3.1)

Fabric Mercerising (3.1.13)


Dyeing (3.2)

Yarn continuous dyeing (3.2.1)




[1] Continuous/Thermosol - Dyeing - Energy requirement (GJ/tonne output): 7,0 – 20,0 Pad/Batch - Dyeing - Energy requirement (GJ/tonne output): 1,5 – 4,5 [4] Woven dyeing - average energy specific consumption 1235,4 kgoe/tonne


Phase (Level 2)

Subphase (Level 3)

Triggers



combinations

Autoclaves (3.2.3) Liquor Ratio (L.R.), Bath temperature, type of fiber, machine type

[4] Yarn dyeing - Average energy specific consumption 1070,2 kgoe/tonne

Hank (3.2.4) Liquor Ratio (L.R.), Bath temperature, type of fiber, machine type

[1] Hank - Dyeing - Energy requirement (GJ/tonne output): 10,0 – 16,0

Jet (3.2.5) Liquor Ratio (L.R.), Bath temperature, type of fiber, machine type

[1] Jet - Dyeing - Energy requirement (GJ/tonne output): 3,5 – 16,0 [4] Dyeing of knitted fabric- Average energy specific consumption 671,5 kgoe/tonne

Overflow (3.2.6) Liquor Ratio (L.R.), Bath temperature, type of fiber, machine type

Winch becks (3.2.7) Liquor Ratio (L.R.), Bath temperature, type of fiber, machine type

Jiggers (3.2.8) Liquor Ratio (L.R.), Bath temperature, type of fiber, machine type

[1] Jig - Dyeing - Energy requirement (GJ/tonne output): 1,5 – 7,0

Dyeing (3.2) Other dyeing machines (3.2.9)

Liquor Ratio (L.R.), Bath temperature, type of fiber, machine type

[1] Beam - Dyeing - Energy requirement (GJ/tonne output): 7,5 – 12,5


Centrifugal hydro-extractors (3.3.1)

Moisture of the fabric at the entrance, type of fiber

Stenter (3.3.2)

Specific weight of fabric g/m2, moisture of the fabric at the entrance, type of fiber, drying temperature fields, velocity of machine

[1] Stenter - Drying - Energy requirement (GJ/tonne output): 2,5 – 7,5 Stenter - Heat Setting - Energy requirement (GJ/tonne output): 4,0 – 9,0

Yarn Dryers (3.3.3)

Moisture of the yarn at the entrance, type of fiber, drying temperature

[1] Hank - Drying - Energy requirement (GJ/tonne output): 4,5 – 6,5


Phase (Level 2)

Subphase (Level 3)

Triggers



combinations

Fabric Dryers (3.3.4)

Specific weight of fabric g/m2, moisture of the fabric at the entrance, type of fiber, drying temperature fields


Specific weight of fabric g/m2, moisture of the fabric at the entrance, type of fiber, drying temperature fields

[1] Steam cylinders - Drying - Energy requirement (GJ/tonne output): 2,5 – 4,5

Tumblers (3.3.6) Type of fiber, drying temperature fields, speed of machine

Finishing machines (3.4)


Machine type, speed of machine

Decatising (3.4.2) Speed of machine, type of fiber, steam pressure

Calenders (3.4.3) Temperature and pressure of the rollers, speed of machine

Singeing machines (3.4.4)

Speed gassing, machine type

Knitwear ironing presses (3.4.5)

Temperature and pressure of the rollers, speed of machine

Tumblers (3.4.6) Type of fiber, drying temperature fields

Sanfor (3.4.7)

Specific weight of fabric g/m2, type of fiber, drying temperature fields, machine type

Other finishing machines (3.4.8)

Variable, depending on the type of machine

Printing (3.5)

Top and yarn printing (3.5.1)

Velocity of machine

Flat screen printing (3.5.2)

Drying temperature fields, machine type

[4] Printing - Average energy specific consumption 411,1 kgoe/tonne

Rotary screen printing (3.5.3)

Drying temperature fields, machine type

[1] Rotary Screen - Printing - Energy requirement (GJ/tonne output): 2,5 – 8,5

Inkjet Printing (3.5.4)

Number of colors, drying temperature

Other printing machines (3.5.5)

Variable, depending on the type of machine


5 - Energy efficiency measures

In this section is presented the list with the state of the art in energy efficiency

measures applicable within the textile industry. The list is divided in four main groups,

three of them complying the specific energy efficiency measures for Yarn Production,

Fabric Production and Finishing and also a group of cross cutting measures.

Specific energy efficiency measures include mostly retrofit/process optimization

measures but also measures considering the complete replacement of the current

machinery with state-of-the-art new technology.

At the end, 105 process specific and 117 cross cutting measures were obtained, mostly

based on Hasenbeigi [1](specific measures) and ARTISAN project (cross cutting

measures). The collected process specific energy efficiency measures result from case

studies around the world published in technical papers, some new available technologies

and the experience and knowledge of SET partners with textile companies. Cross cutting

measures were mostly compiled from ARTISAN (http://www.artisan-project.eu/) and

SESEC (http://www.euratex.eu/sesec/) projects. Based in scientific evidences and with

widespread application (with exception of new technologies), the measures here

presented are a useful guide of good practices to be used by textile companies to increase

their energy efficiency. The applicability of the proposed measures is represented in tables

8 and 9.

Table 8 – Number of specific energy efficiency measures per textile process (process and phase)

Process / Phase (Level 1/ Level 2)

Nº of measures

Process optimization

Newly developed processes

Yarn production (1) - -

Spinning Preparation for cotton fibers (1.1) 2 1

Spinning Preparation for wool fibers (1.2) - -

Production of man-made filaments and fibres (1.3) - -

Spinning (1.4) 20 4

Winding, reeling and covering (1.5) 2 -

Yarn steaming, setting, moistening and coating (1.6) 2 -

Texturing, bulking and crimping (1.7) - -

Doubling and twisting (1.8) 1 -

Fabric production (2) 2 -

Weaving preparation (2.1) 3 -

Weaving (2.2) 7 1

http://www.artisan-project.eu/

http://www.euratex.eu/sesec


Process / Phase (Level 1/ Level 2)

Nº of measures

Process optimization

Newly developed processes

Preparation for knitting (2.3) - -

Knitting (2.4) - -

Finishing (3) 3 -

Pretreatment (3.1) 11 2

Dyeing (3.2) 20 4

Water extraction and drying (3.3) 18 1

Finishing machines (3.4) 1 -

Printing (3.5) - -

Table 9 – Number of cross cutting energy efficiency measures per applicability

Measure applicability Nº of measures

Reduction of peak power 2

Heating/Air conditioning 10

Electric motor 8

Compressed air 17

Pumping systems 17

Fan systems 10

Lighting 10

Steam systems 24

Vacuum systems 3

Cross cutting - general 16

The list of energy efficiency measures are presented in the following tables, together

with a short description of the measure, the applicable process, reference values of

energy savings (fuel and electricity) and an approach of the required investment cost

and the resulting payback period.


NOTE: The energy efficiency measures highlighted in bold are referent to newly developed processes.

23

5.1 - Energy efficiency measures for Yarn Production process

Table 10 – Energy efficiency measures Yarn Production process

Measure (Action) Measure description Applied for Fuel Savings Electricity savings Investment Payback period (years)

Efficient Spindle Oil Use energy efficient spindle oil

Ring-spinning (1.4.1 ) no 3-7% of ring frame energy use

Installation of electronic Roving end-break stop-motion detector instead of pneumatic system

Installation of electronic Roving end-break stop-motion detector

Roving frames (1.1.6) no 3,2 MWh/year/machine

138€/roving machine

< 1

High speed carding machine New machine can be applied for Card

Cards (1.1.2) no yes 77000€/carding machine

<2

Optimum oil level in spindle bolsters

Optimum oil level Ring-spinning (1.4.1 ) no yes

Optimum oil level in spindle bolsters

Optimum oil level Compact spinning (1.4.2)

no yes

Replacement of lighter spindle in place of conventional spindle in Ring frame

Replacement spindle Ring-spinning (1.4.1 ) no 23 MWh/year/ring frame

10500€/ ring frame

8

Replacement of lighter spindle in place of conventional spindle in Ring frame

Replacement spindle Compact spinning (1.4.2)

no 23 MWh/year/ring frame

10500€/ ring frame

8

Synthetic sandwich tapes for Ring frames


Ring-spinning (1.4.1 ) no 4.4-8 MWh/ ring frame/ year

415-525€/ ring frame

1-2




no 4,4-8 MWh/ ring frame/ year

415-525€/ ring frame

1-2

Optimization of ring diameter with respect to yarn count in ring frames

Optimization of ring diameter Ring-spinning (1.4.1 ) no 10% of ring frame energy use

1230€/ ring frame

2



24


Optimization of ring diameter with respect to yarn count in ring frames

Optimization of ring diameter Compact spinning (1.4.2)

no 10% of ring frame energy use

1230€/ ring frame

2

False ceiling in Ring spinning section


Ring-spinning (1.4.1 ) no 8 KWh/ year/spindle 0.54€/spindle 1,2




no 8 KWh/ year/spindle 0,54€/spindle 1,2

Installation of energy efficient motor in ring frame

Installation of energy efficient motor

Ring-spinning (1.4.1 ) no 6,3-18,83 MWh/year/motor

1500-1700€/motor

2-4

Installation of energy efficient motor in ring frame

Installation of energy efficient motor


no 6,3-18,83 MWh/year/motor

1500-1700€/motor

2-4

Installation of energy-efficient excel fans in place of conventional aluminum fans in the suction of Ring Frame

Installation of energy-efficient excel fans

Ring-spinning (1.4.1 ) no 5,8-40 MWh/year/ ring frame

150-240€/ fan

<1

Installation of energy-efficient excel fans in place of conventional aluminum fans in the suction of Ring Frame

Installation of energy-efficient excel fans


no 5,8-40 MWh/year/ ring frame

150-240€/ fan

<1

The use of light weight bobbins in Ring frame

Use of light weight bobbins Ring-spinning (1.4.1 ) no 10,8 MWh/year/ring frame

500€/ ring frame

<1

The use of light weight bobbins in Ring frame

Use of light weight bobbins Compact spinning (1.4.2)

no 10,8 MWh/year/ring frame

500€/ ring frame

<1

High- speed ring spinning frame

High- speed ring spinning frame

Ring-spinning (1.4.1 ) no 10%-20% of ring frame energy use

Installation of soft starter on motor drive of Ring frame

Installation of soft starter on motor drive

Ring-spinning (1.4.1 ) no 1-5,2 MWh/year/ring frame

2

Installation of Variable Frequency Drive in Autocorner machine

Installation of Variable Frequency Drive

Winding machines (1.5.1 )

no 331,2 MWh/year/plant

15000€/plant <1



25


Intermittent mode of movement of empty bobbin conveyor in the Autocorner/cone winding machines

Intermittent mode of movement

Winding machines (1.5.1 )

no 49,4 MWh/year/plant

850€/plant <1

Modified outer pot in Tow-For-One (TFO) machines

Modified outer pot in Tow-For-One (TFO) machines

Doubling machines (1.8.1 )

no 4% of TFO energy use

Optimization of balloon setting in Tow-For-One (TFO) machines

Optimization of balloon setting in Tow-For-One (TFO) machines

Doubling machines (1.8.1 )

no yes

Replacing the electrical heating system with steam heating system for the yarn polishing machine

Replacing the electrical heating system

Heat-setting machines (1.6.2)

increased 31.7 tonnes steam/year/machine

19,5 MWh/year/machine

750€/humidification plant

<1

Grinding of Tambour Sharpening of the surface Spinning Preparation for cotton fibers (1.1)

no yes 150€/card <1

Reduce room temperature Use machine heat for room heating by bypassing the suction exhaust

Rotor spinning (1.4.3) no yes

Monitoring and cleaning of rotor

Cleaning spin box Rotor spinning (1.4.3) no yes

<1

Cleaning of suction van Cleaning wastebox Rotor spinning (1.4.3) no yes

<1 Cleaning of spinnvalve Cleaning nozzle Air-jet spinning (1.4.4) no yes

<1

Use airfree compact Fitting of airfree compact on ringframe

Ring-spinning (1.4.1 ) no yes 11,5/spindle <1

Store yarn for 24 hours Relaxation of yarn Yarn steaming, setting, moistening and coating (1.6)

Don’t need steaming



26

5.2 - Energy efficiency measures for Fabric Production process

Table 11 – Energy efficiency measures Fabric Production process

Measure (Action) Measure description Applied for Fuel Savings Electricity savings Investment

Payback

period

(years)

Start periodic maintenance Maintenance with every article change

Fabric production (2)

Replace gripper Replace gripper Rapier weaving (2.2.1)

Replace gripper Replace projectile gripper Projectile weaving (2.2.2)

Reduce steam temperature Reduce steam temperature, use of pre-wetting and additional dry cylinder.

Sizing/slashing (2.1.5)

Use of cold size agent Use of cold size agent Sizing/slashing (2.1.5) no steam for size box necessary

Use of cold size agent use of cold size agent during beaming can cut out standard sizing for low hairy yarns


no need of separate sizing

6000/beaming machine

<2

Install automated pressure control valves

Pressure control valve Air jet weaving (2.2.3)

300/loom <2

Update nozzle software Software update to optimize the pressure distribution during weft insertion


Use on-loom fabric inspection install a on-loom inspection system to minimize fabric inspection after weaving

Weaving (2.2)

1000/loom <2



27

Measure (Action) Measure description Applied for Fuel Savings Electricity savings Investment

Payback

period

(years)

Install mechanic selvage picker Replace air picker with mechanic picker


reduce 1/3 of compressed air consumption per loom

800/loom <2

Replace single width loom Install double width loom for high volume articles

Weaving (2.2)

30000/loom <3

Install lower roof Reduce roof height to minimize the air volume of the room

Weaving (2.2)



28

5.3 - Energy efficiency measures for Finishing process

Table 12 – Energy efficiency measures Finishing process

Measure (Action) Measure description Applied for Fuel Saving Electricity

Savings Investment

Cost

Payback period (years)

Combine Preparatory Treatments in wet processing

Combine preparatory treatments in order to lead to a reduction in process steps.

Pretreatment (3.1)

up to 80% of Preparatory Treatments energy use

Cold-Pad-Batch pretreatment

Embed hydrogen peroxide into the fabric using a padder, and the fabric is then stored to allow complete reaction between the fabric and chemicals prior to rinse.


up to 38% of pretreatment fuel use

up to 50% of pretreatment electricity use

Bleach bath recovery system

Recycling and reuse of bleach bath.


30000€ -93000€ saving (net annual operating savings (average per plant) which includes energy and non-energy savings)

Use of Counter-flow Current for washing

In this system, as the fabric runs through the washing compartments from entry to exit, clean water is passed through the plant from the back to the front. This means that the cleanest fabric comes into contact with the cleanest washing liquor.


41% - 62% of washing energy use



29


Savings Investment

Cost


Installing Covers on Nips and Tanks in continuous washing machine

The losses at nips are considerable. Hence, it is important to cover them as well as the hot tanks. Any fitted covers should be easily removable to allow quick access.


36%

Installing automatic valves in continuous washing machine

Automatic stop valves which link the main drive systems of machines to water flows can save considerable amounts of energy and water by shutting off water flow as soon as a stoppage occurs.


Yes < 0,5

Installing heat recovery equipment in continuous washing machine

Installing heat recovery equipment on a continuous washer is usually a simple but very effective measure since water inflow and effluent outflow are matched and this eliminates the need for holding tanks.


Yes

Reduce live steam pressure in continuous washing machine

A reduction in live steam pressure can prevent steam breakthroughs, thus improving heat transfer efficiency in direct steam heating applications. Similarly, reducing steam pressure in closed coils will have take advantage of the fact that lower pressure steam has higher latent heat content.


Yes



30


Savings Investment

Cost


Introducing Point-of-Use water heating in continuous washing machine

Point-of-use gas-fired water heaters can be used to enable processes to be run independently of plant central boiler systems. This means that boiler and distribution losses associated with centralized systems can be eliminated.


<50% High

Interlocking the running of exhaust hood fans with water tray movement in the yarn mercerizing machine

Electrically interlock the exhaust hood fans with the forward movement of the water tray, as the fans usually have to remove the fumes generated during the washing phase only.



<0,5

Energy saving in cooling blower motor by interlocking it with fabric gas singeing machine's main motor

Interlock the cooling blower motor with the singeing machine’s main motor, thereby saving energy.

Singeing (3.1.2) 2,43 MWh/year/machine

< 0,5

Energy saving in shearing machine's blower motor by interlocking it with the main motor

The interlocking of blower motors with the machine’s main motor can be implemented in fabric shearing machines.



< 0,5

Enzymatic removal of residual hydrogen peroxide after bleach

Rinsing steps after peroxide bleaching can be reduced with enzymatic peroxide removal (normally only one rinsing step with hot water is necessary).


2780 GJ/year/plant

Enzymatic scouring With the use of enzymes the alkaline scouring process can be replaced.


Yes



31


Savings Investment

Cost


Installation of Variable Frequency Drive on pump motor of Top dyeing machines

Variable frequency drives (VFDs) can be installed on the pump motor of the top dyeing machine in order to save energy by setting the speed of the pump motor based on the dyeing process requirements.

Autoclaves (3.2.3)


2400€ /machine 1,5

Heat Insulation of high temperature/ high pressure dyeing machines

Insulation of pipes, valves, tanks and machines is a general principle of good housekeeping practice that should be applied in all steam consuming processes in textile plants. The insulation material may be exposed to water, chemicals and physical shock. Any insulation should, therefore, be covered or coated with a hard-wearing, chemical/water resistant outer layer.

Autoclaves (3.2.3)

2% in steam consumption per kilogram of dyed yarn



32


Savings Investment

Cost


Heat Insulation of high temperature/ high pressure dyeing machines

Insulation of pipes, valves, tanks and machines is a general principle of good housekeeping practice that should be applied in all steam consuming processes in textile plants. The insulation material may be exposed to water, chemicals and physical shock. Any insulation should, therefore, be covered or coated with a hard-wearing, chemical/water resistant outer layer.

Jet (3.2.5) 4 GJ/tonne fabric/plant

6,3 kWh/tonne fabric

4€/tonne of fabric

Automated preparation and dispensing of chemicals in dyeing plants

Automatic preparation and dispension of chemicals generate a reduction of consumption of chemicals, energy and water and an increase of reproducibility.

Dyeing (3.2) Yes

Chemical Dispensing System: 117500€ -698000€ ; Dye Dissolving and Distribution: 78500€ - 313750€; Bulk Powder Dissolution and Distribution: 59500€ - 470500€

1,3 - 6,2 ; 4 - 5,7 ; 3,8 - 7,5



33


Savings Investment

Cost


Automatic dye machine controllers

Automatic dye machine controllers offer an effective means for enhanced control over dyeing processes, based on microprocessors, allowing for feedback control of process parameters such as pH, color, and temperature. They analyze process parameters continuously and respond more quickly and accurately than manually controlled systems.

Dyeing (3.2) Yes 44700€ - 117600€/system

1 - 5

Cooling water recovery in batch dyeing machines (Jet, Beam, Package, Hank, Jig and Winches)

Cooling water and condensate water can be pumped to hot water storage tanks for reuse in functions where heated water is required.

Dyeing (3.2) 1,6 - 2,1 GJ/tonne fabric

112000€ - 166000€/system

1,3 - 3,6

Cold-Pad-Batch dyeing system

Impregnate the fabric with liquor containing premixed fiber-reactive dyestuff and alkali. Excess liquid is squeezed out on a device known as a mangle. The fabric is then batched onto rolls or into boxes and covered with plastic film to prevent absorption of CO2 from the air and evaporation of water. The fabric is then stored for 2 – 12 hours.


16,3 GJ/tonne of dyed fabric

953000€/ system 1,4 - 3,7



34


Savings Investment

Cost


Discontinuous dyeing with airflow dyeing machine

Airflow dyeing machines have lower liquor ratios than conventional jet dyeing machines. To achieve those low liquor ratios, within the jet dyeing machine the fabric is moved by moisturized air or a mixture of steam and air only (no liquids), aided by a winch. The prepared solutions of the dyestuffs, auxiliaries and basic chemicals are injected into the gas stream.

Jet (3.2.5) up to 60% of machine's fuel use

149500€ - 284000€/machine

Installation of VFD on circulation pumps

Circulation pumps are used to circulate chemicals in machine chambers in the dye house. VFDs can be installed instead of ball valves for flow control, thereby saving energy.

Dyeing (3.2) 138 MWh/year/plant

1800€/plant < 1

Dyebath Reuse

Dyebath reuse is the process by which exhausted hot dyebaths are analyzed for residual colorant concentrations, replenished, and reused to dye additional batches of material.

Dyeing (3.2) 3500€ saving/ dye machine

18800€ - 26600/dye machine



35


Savings Investment

Cost


Single-rope flow dyeing machines

The way in which these machines handle the fabric and the dyeing cycle is very different from conventional rope dyeing machines. First, there is only one fabric rope which passes through all flow groups and compartments, returning to the first compartment after the lap is complete.


2,5 kg steam /kg fabric

0,16 - 0,20 kWh/kg fabric

< 1



36


Savings Investment

Cost


Microwave dyeing equipment

Microwave dyeing equipment employs microwaves for rapid, efficient and energy-saving dispersion and penetration of dyes and chemicals into fabric. Since microwave irradiation generates heat through dielectric losses, the heat is absorbed by objects having large losses, and thus fabric containing moisture is heated without heating of the surrounding air and equipment itself. Furthermore, in contrast to the case of moisture (dyeing solution) penetrating the fabric, the fabric itself becomes a steam generator through internal heating, and penetration and dispersion of dyes and chemicals occurs rapidly and uniformly, ensuring suitability for continuous dyeing in mass production.


96% reduction compared to beam dyeing

90% reduction compared to beam dyeing

353000€/ machine

Reducing the process temperature in wet batch pressure-dyeing machines

A reduction in the process temperature may also be achieved in wet batch pressure-dyeing machines by introducing alternative processes.

Dyeing (3.2) Yes



37


Savings Investment

Cost


Use of steam coil instead of direct steam heating in batch dyeing machines (Winch and Jigger)

In older batch dyeing machines like winches and jiggers, dyebaths are traditionally heated by sparging with raw steam. This is a very inefficient use of steam for heating the dyebath. A steam coil submerged in the dyebath now allows for the recycling of the condensate, resulting in significant fuel savings.

Dyeing (3.2) 4580 GJ/year/plant 130000€/plant

Reducing the process time in wet batch pressure-dyeing machines

Processing times can sometimes be reduced simply by making modifications to the temperature profiles of certain dyeing cycles.

Dyeing (3.2) Yes

Installation of covers or hoods in atmospheric wet batch machines

Using covers or hoods can reduce evaporative losses by approximately half.

Dyeing (3.2) Yes

Careful control of temperature in atmospheric wet batch machines

Better temperature control in order to decrease steam comsuption when the process temperature is reached.

Jiggers (3.2.8) 27 - 91 kg steam/hour



38


Savings Investment

Cost


Jiggers with a variable liquor ratio

A new generation of jiggers with a variable liquor ratio has been developed in order to be able of processing. These jiggers make use of a heat exchanger, allowing the heat to be removed and applied elsewhere in the plant. In each passage, the length of the cloth is measured, so extra fabric at the end of the batch can be avoided.

Jiggers (3.2.8) 26% reduction compared to conventional jigger

Heat recovery of hot waste water in Autoclave

Installation of a heat exchanger and surrounding equipment like water tanks and pumps for recovering heat from hot waste water as a heat source.

Autoclaves (3.2.3)

554 MJ/batch product

Insulation of un-insulated surface of Autoclave

All the hot surfaces should be insulated, including those of the main vessel, air vent tank, heat exchanger and water circulation piping. Water-resistant, easy-paste type insulation material is usually recommended.

Autoclaves (3.2.3)

15 MJ/batch product

Reducing the need for re-processing in dyeing

Improving process control either mannually through better staff training or using specific software.

Dyeing (3.2) 10% -12%

Recover heat from hot rinse water

Capture the heat from the rinse water and use it for pre-heating the incoming water for the next hot rinse.

Dyeing (3.2) 1,4 - 7,5 GJ/tonne fabric rinsed

34500€ -74500€ < 0,5



39


Savings Investment

Cost


Reuse of washing and rinsing water

After discontinuous dyeing, the final-step rinse water is hardly contaminated and can possibly be reused for the first rinsing step of the next dyeing process.

Dyeing (3.2) Yes

Reduce rinse water temperature

Reduce temperature of rinse water for rinsing after dyeing to about 50°C can be done without degrading product quality.

Dyeing (3.2) 10% 0

Introduce Mechanical Pre-drying

Mechanical pre-drying methods such as mangling, centrifugal drying, suction slot or air knife de-watering are used to reduce drying costs by removing some of the water from the fabric prior to contact drying in cylinder dryer.


Yes

Recover Condensate and Flash Steam

Since a large amount of steam is used in cylinder dryer, there is also a significant amount of condensate that should be recovered and returned to the boiler house. In addition, flash steam which is produced when condensate is reduced to atmospheric pressure can be recovered as low-pressure steam, and used to heat water or other low-pressure steam processes.


Yes

End Panel Insulation Insulation of end sections of the cylinder dryers.


Yes



40


Savings Investment

Cost


Avoid Intermediate Drying

There are systems which allow finishes to be applied ‘wet on wet’ to avoid intermediate drying between processes.


Yes

Avoid Overdrying

Control the speed of the drying cylinders so that the equilibrium moisture level of the fibre is not exceeded.


Yes

Reduce Idling Times and Use Multiple Fabric Drying

Careful scheduling of fabric batches arriving at the cylinders to reduce idling time, and make cylinders extra wide to allow two batches of narrow fabric to run side by side.


Yes

Maintenance of the cylinder dryer

Avoid steam leaks performing adequate maintenance.


The use of radio frequency dryer for drying acrylic yarn

The steam heated dryer, which is used to dry dyed acrylic yarn skeins, can be replaced by a radio frequency dryer.

Yarn Dryers (3.3.3)

35300€ saving/plant 157000€/plant

The use of Low Pressure Microwave drying machine for bobbin drying instead of dry-steam heater

Switching the drying of bobin products from dry-steam heaters to low pressure (LP) microwave drying.

Yarn Dryers (3.3.3)

Yes 107 kWh/tonne yarn

392000€/plant < 3



41


Savings Investment

Cost


Conversion of Thermic Fluid heating system to Direct Gas Firing system in Stenters and dryers

Replace thermal fluid heaters by direct gas firing systems. In the new system, air is directly heated by gas fired burners and the required temperature is obtained by circulating hot air through the chambers. This measure provides savings on fuel consumption with the reduced heat losses and on the electricity required for pumping the thermic fluid.

Stenter (3.3.2) 11000 GJ/year/plant 120 MWh/year/plant

39200€/plant 1

Introduce Mechanical De-watering or Contact Drying Before Stenter

Use mechanical water extraction equipment such as mangles, centrifuges, suction slots and air knives; or contact drying using heated cylinders.

Stenter (3.3.2) 13% - 50% of stenter energy use

Avoid Overdrying Control the speed of the stenter so that the equilibrium moisture level of the fibre is not exceeded.

Stenter (3.3.2) Yes

Close Exhaust Streams during Idling

Perform proper scheduling to minimize machine stops and close exhausts during idling times.

Stenter (3.3.2) Yes

Proper Insulation Proper insulation of stenter envelopes reduces heat losses to a considerable extent.

Stenter (3.3.2) 20% of stenter energy use



42


Savings Investment

Cost


Optimize Exhaust Humidity

In order to optimize drying rates and energy use, air flows through the oven (and therefore the exhaust rate) must be carefully controlled, analysing the moisture content of the exhaust air.

Stenter (3.3.2) 20 - 80% of stenter energy use

Install Heat Recovery Equipment

Heat-recovery air/air: Uses exhaust air heat to heat up fresh air supplied to the stenter

Stenter (3.3.2) Yes

Install Heat Recovery Equipment

Heat-recovery air/water: Uses exhaust air heat to heat up service water for wet finishing (for example washing, dyeing, and bleaching.)

Stenter (3.3.2) 30% of stenter energy use

60400€ - 361000€/system

1,5-6,6

Efficient burner technology in Direct Gas Fired systems

Optimized firing systems and sufficient maintenance of burners in direct gas-fired stenters can minimize methane emissions, which is important because methane emissions from burners greatly determine actual burner capacity. Stenters should receive general maintenance by specialized companies at regular intervals. There should also be routine checking of the burner air inlet for blockings by lint or oil, cleaning of pipe works to remove precipitates and adjusting of burners by specialists.

Stenter (3.3.2) Yes



43


Savings Investment

Cost


The Use of Sensors and Control Systems in Stenter

Install sensors and control systems such as: Exhaust humidity measurement; Residual moisture measurement; Fabric and air temperature measurement; Process visualization systems

Stenter (3.3.2) 22% of stenter fuel use

11% of stenter electricity use

moisture humidity controllers: 15700€ – 172500€; dwell time controls: 63000€ – 314000€

moisture humidity controllers: 1,5 - 5 ; dwell time controls: 4 - 6,7

Automatic steam control valves in Desizing, Dyeing, and Finishing

Replace the manual steam control system with an automatic one, which controls the steam supply to each process according to its needs.

Finishing (3) 3250 GJ/year/plant 4000€/plant

The recovery of condensate in wet processing plants

Recover the condensate to return it to the boiler and convert it back into new steam or use it as a water supply for washing or desizing, thereby recovering both water and heat.

Finishing (3) 1,3 - 2 GJ/tonne fabric

800€ - 12500€ 1 - 6

Utilization of heat exchanger for heat recovery from wet-processes wastewater

Recover the energy of heated waste water from rinsing in the desizing, scouring, and bleaching steps of continuous preparation ranges as well as in dyeing machines.

Finishing (3) 1,1 – 1,4 GJ/tonne finished fabric

258000€ / system


44

5.4 - Cross-cutting energy efficiency measures

Table 13 – Cross cutting energy efficiency measures

Measure (Action) Measure description Applied for Fuel Saving Electricity Savings Investment Cost Payback period (years)

Reconsideration of electric supply contract.

It is an economic measure 0% (no energy saving, but there may be economic saving)

Negligible Immediate

Reconsideration of thermal supply contract / cost of used combustibles.

It is an economic measure

0% (no energy saving, but there may be economic saving)


Shifting of energivorous processes towards lower price time slots.

Reduction of peak power

0% (no energy saving, but there may be economic saving)

Slight Immediate

Use of work-shifts. Reduction of peak power

Low/Medium Immediate

Removal of covering / impediments from heating appliances and air conditioners.

Heating/Air conditioning

from 0 to 1% of factory thermal consumption

from 0 to 1% of factory electrical consumption

Slight Short - Short/Medium - Medium

Adoption of high efficiency window frames.


from 0 to 20% of thermal consumption in shed building with window frames in polycarbonate and where the heat is only used for building heating

Low/Medium Medium


45


Exterior Insulation and Finishing System (EIFS).


from 0 up to 50% of thermal consumption in case of heat used only for building heating

Medium/High Medium - Medium/Long

Limitation of heated / conditioned volumes (it can be sufficient to spread a nylon sheet).


up to 3% of factory thermal consumption

up to 2% of factory electric consumption

Low - Low/Medium Medium - Variable

Set thermostats to minimum for comfort (20ºC in winter and 25ºC in summer).


Variable, A typical value is < = 1% of factory thermal consumption

Variable A typical value is 1,5% of factory electrical consumption

Null immediate

Guarantee closed passages between acclimatized and non acclimatized areas.

Minimise loss of hot/cold air. Use air curtains when passages from climatized and non climatized areas are usually and inevitably open.


Variable < = 1% of factory thermal consumption

Variable < = 1% of factory electrical consumption

Slight immediate

Use heat/cooling only when area is occupied.

Applies for comfort areas, technical areas such as server rooms, display rooms, etc. should be analyzed seperatly.




Null immediate

Clean and effective heaters/coolers. Verify dirt deposition in all heat transfer surfaces.




Negligible immediate


46


Adoption of sunbreakers / curtains.


from 0 to 1% of factory electrical consumption (energy savings related to lower use of the air-conditioning)

Low Short/Medium

Adoption of high efficiency electric engine.

Electric motor

from 0 up to 10% of factory electrical consumption in case of obsolete engines

High Medium - Medium/Long

Adoption of inverters for electric motor.

Adjustable-speed drives better match speed to load requirements for motor operations, and therefore ensure that motor energy use is optimized to a given application.

Electric motor 2% - 60% Medium from 0,8 to 2,8 years


47


Adoption of motor management plan.

A motor management plan is an essential part of a plant’s energy management strategy. Having a motor management plan in place can help companies realize long-term motor system energy savings and will ensure that motor failures are handled in a quick and cost effective manner. The Motor Decisions Matter Campaign suggests the following key elements for a sound motor management plan (CEE, 2007): 1. Creation of a motor survey and tracking program. 2. Development of guidelines for proactive repair/replace decisions. 3. Preparation for motor failure by creating a spares inventory. 4. Development of a purchasing specification. 5. Development of a repair specification. 6. Development and implementation of a predictive and preventive maintenance program.

Electric motor


48


Maintenance of motors.

The purposes of motor maintenance are to prolong motor life and to foresee a motor failure.

Electric motor 2% - 30% of motor system energy use

Rewinding of motors.

In some cases, it may be cost-effective to rewind an existing energy-efficient motor, instead of purchasing a new motor.

Electric motor

Proper motor sizing. Electric motor

Power factor correction.

The power factor can be corrected by minimizing idling of electric motors (a motor that is turned off consumes no energy), replacing motors with premium-efficient motors, and installing capacitors in the AC circuit to reduce the magnitude of reactive power in the system (U.S. DOE, 1996).

Electric motor


49


Minimizing voltage unbalances.

Electric motor

The typical payback period for voltage controller installation on lightly loaded motors in the U.S. is 2,6 years (U.S. DOE-IAC, 2006)

Reduction of demand throught reduction of compressed air production pressure.

Compressed air

from 0 to 1% of electrical consumption if the compressed air is used improperly for cleaning reasons from 0 to 0,1% in other cases

Null Immediate

Reduction of leaks in compressed air pipes and equipment.

Leaks cause an increase in compressor energy and maintenance costs. The most common areas for leaks are couplings, hoses, tubes, fittings, pressure regulators, open condensate traps and shut-off valves, pipe joints, disconnects and thread sealants.

Compressed air up to 20% of compressed air system energy use

Low Short - Short/Medium


50


Installation of compressed air accumulation tanks.

Compressed air about 0% Low - Low/Medium Short - Short/Medium

Recovery of heat from compressors.


Medium < 1

Install low-cost solenoid valves on air supply lines to individual machines. Switch off compressed air supply as soon as machine is switched off.

Compressed air Variable < = 1% of electrical consumption

Low Short

Use lowest air intake temperature possible in compressors. Duct air intake to ensure coolest possible and/or pre-cool it.

Reducing the inlet air temperature reduces energy used by the compressor. In many plants, it is possible to reduce this inlet air temperature by taking suction from outside the building.

Compressed air each 3°C reduction will save 1% compressor energy use

Low/Medium < 5

Check on correct pressure setting regularly to reduce the demand.

Compressed air < = 1% of electric consumption

Null immediate

Replace pneumatic tools by electrical tools to reduce the demand.

Compressed air < = 1% of electric consumption

Low/Medium Short

Do not use compressed air for cleaning operations. Use of vacuum cleaner instead of compressed air.

Compressed air Variable < = 1% of electrical consumption

Negligible immediate


51


Maintenance of compressed air plant.

Inadequate maintenance can lower compression efficiency, increase air leakage or pressure variability and lead to increased operating temperatures, poor moisture control and excessive contamination. Better maintenance will reduce these problems and save energy.

Compressed air

Monitoring of compressed air plant.

Maintenance can be supported by monitoring using proper instrumentation, including (CADDET, 1997): • Pressure gauges on each receiver or main branch line and differential gauges across dryers, filters, etc. • Temperature gauges across the compressor and its cooling system to detect fouling and blockages. • Flow meters to measure the quantity of air used. • Dew point temperature gauges to monitor the effectiveness of air dryers. • kWh meters and hours run meters on the compressor drive.

Compressed air


52


Adoption of electronic condensate drain traps (ECDTs) for compressed air plant.

Due to the necessity to remove condensate from the system, continuous bleeding, achieved by forcing a receiver drain valve to open, often becomes the normal operating practice, but is extremely wasteful and costly in terms of air leakage. Electronic condensate drain traps (ECDTs) offer improved reliability and are very efficient as virtually no air is wasted when the condensate is rejected.

Compressed air

Maximizing allowable pressure dew point at air intake in compressed air system.

Choose the dryer that has the maximum allowable pressure dew point, and best efficiency. A rule of thumb is that desiccant dryers consume 7 to 14% and refrigerated dryers consume 1 to 2% of the total energy of the compressor (Ingersoll-Rand, 2001). Consider using a dryer with a floating dew point. Note that where pneumatic lines are exposed to freezing conditions, refrigerated dryers are not an option.

Compressed air


53


Optimizing the compressor to match its load.

Some plants have installed modular systems with several smaller compressors to match compressed air needs in a modular way (Cergel et al., 2000). In some cases, the pressure required is so low that the need can be met by a blower instead of a compressor which allows considerable energy savings, since a blower requires only a small fraction of the power needed by a compressor (Cergel et al., 2000).

Compressed air

Proper pipe sizing for compressed air plant.


Adoption of inverters for electric motors of compressed air plant.

When there are strong variations in load and/or ambient temperatures there will be large swings in compressor load and efficiency.

Compressed air

Implementing adjustable speed drives in rotary compressor systems has saved 15% of the annual compressed air system energy consumption

Medium

Remove/isolate "dead-legs" and redundant Pipework of compressed air system.

Compressed air

Use of high efficiency pump for sewages.

Pumping systems

< = 1% of electrical consumption

Variable Variable


54


Maintenance of pumping systems.

Inadequate maintenance lowers pump system efficiency, causes pumps to wear out more quickly and increases costs. Better maintenance will reduce these problems and save energy. Proper maintenance includes the following (Hydraulic Institute, 1994; U.S. DOE, 1999): • Replacement of worn impellers, especially in caustic or semi-solid applications. • Bearing inspection and repair. • Bearing lubrication replacement, once annually or semiannually. • Inspection and replacement of packing seals. • Inspection and replacement of mechanical seals. • Wear ring and impeller replacement. • Pump/motor alignment check. • The largest opportunity is usually to avoid throttling losses.

Pumping systems

2% - 7% of pumping electriccity use

< 1


55


Monitoring of pumping systems.

Monitoring in conjunction with operations and maintenance can be used to detect problems and determine solutions to create a more efficient system. Monitoring can determine clearances that need be adjusted, indicate blockage, impeller damage, inadequate suction, operation outside preferences, clogged or gas-filled pumps or pipes, or worn out pumps. Monitoring should include: • Wear monitoring • Vibration analyses • Pressure and flow monitoring • Current or power monitoring • Differential head and temperature rise across the pump (also known as thermodynamic monitoring) • Distribution system inspection for scaling or contaminant build-up

Pumping systems


56


Controls for pumping systems.

The objective of any control strategy is to shut off unneeded pumps or to reduce the load of individual pumps. Remote controls enable pumping systems to be started and stopped relatively quickly and accurately, and reduce the required labor with respect to traditional control systems.

Pumping systems

Reduction of demand for pumping systems.

Holding tanks can be used to equalize the flow over the production cycle, enhancing energy efficiency and potentially reducing the need to add pump capacity. In addition, bypass loops and other unnecessary flows should be eliminated. Energy savings may be as high as 5-10% for each of these steps (Easton Consultants, 1995).

Pumping systems

Adoption of more efficient pumps.

Pumping systems

2% - 10% of pumping electricity use

Proper pump sizing. Pumping systems

Correcting for pump oversizing can save 15% to 25% of electricity consumption for pumping (on average for the U.S. industry) (Easton Consultants, 1995).

< 1


57


Multiple pumps for varying loads.

Pumping systems

The installation of parallel systems for highly variable loads on average would save 10% to 50% of the electricity consumption for pumping for the U.S. industry (Easton Consultants, 1995).

Impeller trimming (or shaving sheaves) for pumping systems.

Trimming reduces the impeller’s tip speed, which in turn reduces the amount of energy imparted to the pumped fluid; as a result, the pump’s flow rate and pressure both decrease. A smaller or trimmed impeller can thus be used efficiently in applications in which the current impeller is producing excessive heat (U.S. DOE-OIT, 2005).

Pumping systems

In the food processing, paper and petrochemical industries, trimming impellers or lowering gear ratios is estimated to save as much as 75% of the electricity consumption for specific pump applications (Xenergy, 1998).

Adjustable speed drives (ASDs) for pumping systems.

Pumping systems

20% - 50% of pumping electricicy use


58


Avoiding throttling valves for pumping systems.

Variable speed drives or on-off regulated systems always save energy compared to throttling valves (Hovstadius, 2002).The use of these valves should therefore be avoided. Extensive use of throttling valves or bypass loops may be an indication of an oversized pump (Tutterow et al., 2000).

Pumping systems

Proper pipe sizing for pumping plant.

Pumping systems

Replacement of belt drives in pumping systems.

Pumping systems

up to 8% of pumping electricity use

< 0,5

Precision castings, surface coatings or polishing in pumping systems.

The use of castings, coatings or polishing reduces surface roughness that in turn, increases energy-efficiency. It may also help maintain efficiency over time. This measure is more effective on smaller pumps.

Pumping systems


59


Improvement of sealing in pumping systems.

Seal failure accounts for up to 70% of pump failures in many applications (Hydraulic Institute and Europump, 2001). The sealing arrangements on pumps will contribute to the power absorbed. Often the use of gas barrier seals, balanced seals, and no-contacting labyrinth seals can help to optimize pump efficiency.

Pumping systems

Repair leaks in ventilation pipework.

Fan systems Variable < = 1% of electrical consumption

Low Short

Minimizing pressure in fun systems.

Fan systems

Control density in fun systems.

Temperature, moisture, molecular weight, elevation, and the absolute pressure in the duct or vessel affect the density of the transporting gas. A density change may affect the hardware requirements for the system.

Fan systems

Fan efficiency. Fan systems Proper fan sizing. Fan systems 1-5% Adjustable speed drives (ASDs) for fan systems.

Fan systems 14% - 49% of fan system electricity use


60


High efficiency belts (cogged belts) for fan systems.

Standard Vbelts tend to stretch, slip, bend and compress, which lead to a loss of efficiency. Replacing standard V-belts with cogged belts can save energy and money, even as a retrofit.

Fan systems 2% of fan system electricity use

1- 3 years

Adoption of proximity sensors for not permanently used places.

Lighting from 0 to 2% of factory electrical consumption

Slight < 2

Substitution of mercury-vapor lamps with fluorescent tubes in low buildings.


Low - Low/Medium - Medium

Short

Adoption of LED Lamps. Lighting from 0 to 5% of factory electrical consumption

Medium - Medium/High

Medium

Down lamps or lower the ceiling.


Variable Variable

Maintain lamps and fixtures clear of light-blocking dust and dirt.

Lighting


Slight immediate

Make the best use of daylight.

In addition to optimizing the size of the windows, a transparent sheets can be installed at the roof in order to allow more sunlight to penetrate into the production area. This can reduce the need for lighting during the day.

Lighting Variable < = 1% of factory electrical consumption

Variable Short/Medium


61


Avoid the absorption of light by the surroundings (light-coloured wall, ceilings, and floors).

Lighting


Low Short

Replace magnetic ballasts with electronic ballasts.

A ballast is a mechanism that regulates the amount of electricity required to start a lighting fixture and maintain a steady output of light.

Lighting

Electronic ballasts save 12 – 25% of electricity use compared to magnetic ballast.

Optimization of plant lighting (lux optimization) in production and non-production departments.

Lighting

Adoption of dimmer to reduce the use of artificial light.

Lighting

Reduction of steam production pressure.

Steam systems up to 2% of factory thermal consumption

Null Immediate

Installation of steam accumulation tanks.

Steam systems about 0% Low - Low/Medium Immediate


62


Heat recovery from the boiler / steam generator smokes.

Heat from flue gases can be used to preheat boiler feed water in an economizer. By preheating the water supply, the temperature of the water supply at the inlet to the boiler is increased, reducing the amount of heat necessary to generate steam thus saving fuel.

Steam systems 5% Low - Low/Medium 2 - 4 years

Improvement of insulation of water / steam pipes.

Steam systems

up to 3% of thermal consumption up to 1% of electric consumption

Variable 1 years

Adoption of high efficiency boilers / steam generators.

Steam systems

from 0 to 4% of factory thermal consumption (in Italy) and up to 20% in disadvantaged backgrounds

Medium/High Medium

Condensates recovery in steam system.

Steam systems up to 5% Variable 1 years

Installation of cogeneration plant.

Steam systems

0% (no energy savings, but efficiency at the country level and economic saving for the company)

High Medium/Long


63


Reduce excess combustion air to minimum by CO2/O2 measurement.

Steam systems on average 2,3% of factory thermal consumption

Low < 1

Maximise completeness of combustion by Soot/CO measurement.

Steam systems < = 1% of factory thermal consumption

Low < 1

Maintain boiler cleanliness (soot/scale) by monitor for rise in flue gas temperature.


Low Short

Repair (replace) boiler and feedwater tank insulation.

Steam systems 6% - 26% of boiler energy use

Low/Medium Short

Replace steam traps with sensor controlled magnetic valves (Condensate output on demand with minimum loss of fresh steam.).

Steam systems on average 1,5% of factory thermal consumption

Medium Medium

Insert valves to isolate "periodic-use" items in steam system.


Low/Medium Medium

Remove/isolate "dead-legs" and redundant pipework of steam distribution system


Low/Medium Medium


64


Eliminate uneconomic “hot standby” periods, maintain heat supply only if absolutly necessary.

Steam systems

Variable A typical value is 1,1% of factory thermal consumption

Slight Short

Demand matching for steam generation.

A boiler is more efficient in the high-fire setting.

Steam systems < 2

Boiler allocation control for steam generation.

Systems containing multiple boilers offer energy-saving opportunities by using proper boiler allocation strategies. This is especially true if multiple boilers are operated simultaneously at low-fire conditions.

Steam systems

Flue shut-off dampers for steam generation.

Where boilers are regularly shut down due to load changes, the heat lost to the chimney can be significant. A solution to stop this loss of hot air is to fit fully closing stack dampers, which only operate when the boiler is not required. Another alternative is to fit similar gas tight dampers to the fan intake (CADDET, 2001).

Steam systems


65


Maintenance of steam system.

In the absence of a good maintenance system, the burners and condensate return systems can wear or get out of adjustment.

Steam systems up to 10% of boiler energy use

The establishment of a maintenance schedule for boilers has an average payback time of 0,3 years (U.S. DOE-IAC, 2006).

Optimization of boiler blowdown rate.

Steam systems

Recovery of heat from boiler blowdown.

Steam systems

The use of heat from boiler blow down on average has payback period of 1,6 years (U.S. DOE-IAC, 2006).

Proper pipe sizing for steam distribution plant.

Steam systems


66


Reduction of distribution pipe leaks in steam plant.

Steam systems

On average leak repair has a payback period of 0,4 years (U.S. DOE-IAC, 2006).

Repair leaks in vacuum pipework.

Vacuum systems


Low Short

Use a central vacuum system with variable speed and pressotatic control and with several delivery points equipped with dampers.

Vacuum systems

< = 1% of factory electrical consumption

Medium/High Medium/Long


67


Use dedicated vacuum systems in machines with low work regime or geografically offset from central system. Applies to machines with frequent changes, variable workhours and/or far from centralized system. if all machines suffer from such variancy, dedicated systems are more efficient than centralized ones.

Vacuum systems


Variable Variable

Adoption of solar thermal collector.

from 0 to 4% of thermal consumption for building heating

Low Short

Replacement of fossil fuels with renewable fuels.


Variable Variable

Replacement of electrical heater with fire heater.

from 0 to 1% of overall thermal consumption

Variable Variable


68


Installation of trigeneration plant.


High Long

Switch off the machines and turn off the lights during the lunch break.



Establish Energy Monitoring and Energy Management System.

Develop and implement a system to monitor the energy consumption in the enterprise. Establish an Energy Management System (ofthe the easiest way is to integrate it into existing quality management systems). Set up the sensors, which are needed to monitor the imporrant consumptions.

Variable Variable Medium/High Varible


69


Identify excess non-variant consumption and turn off unneeded capacity.

Analyse the relation between consumption and production output. You can do this using the SESEC-Benchmark Tools. In general the energy consumption consist of a fixed part (like heating of buildings, lighting of offices) and a variable part, depending on the utilization of machines. A high fixed part may be reduced. A curve which increases more than linear might hint some production-planning optimizations potentials. It might be necessary to have a look at the departments seperately.

Variable < = 1% of electrical and thermal consumption

Variable < = 1% of electrical and thermal consumption

Slight Varible

Raise awareness of energy saving in all workers.

Train all staff to operate manual controls, to watch for energy saving opportunities, use posters, “switch-off”and “save-it” stickers as a tool of good housekeeping.

< = 1% of electrical and thermal consumption

< = 1% of electrical and thermal consumption

Low/Medium Short

Reduce the amount of ventilation by control optimization with a timer switch and/or occupancy sensor.


Low Medium


70


Use free-cooling whenever possible.

Avalilable when the outside temperature is lower than the inside and cooling is rquired, ex. cooling production plant in winter. Cold tab-water maybe used to cool machines and get waremd up at the same time.


Variable Medium

Preheating boiler feed water with heat from flue gas (economizer)

Preheating water Steam systems 5% - 10% of boiler energy use

< 2

Replacement of nozzles with energy efficient mist nozzles in yarn conditioning room

Replacement of nozzles Heating/Air conditioning

31 MWh/year/humidification plant


<1

Installation of Variable Frequency Drive (VFD) for washer pump motor in Humidification plant

Installation of VFD Pumping systems



<1

Replacement of the existing Aluminium alloy fan impellers with high efficiency F.R.P (Fobreglass Reinforced Plastic) impellers in humidification fans and cooling tower fans

Replacement of the existing Aluminium alloy fan

Fan systems 55,5 MWh/year/fan 500€/fan <1


71


Installation of VFD on Humidification system fan motors for the flow control

Installation of VFD Fan systems 18-105 MWh/year/fan 1450-6660€/fan 1-2

Installation of VFD on Humidification system pumps

Installation of VFD Pumping systems

35 MWh/year/ humidification plant


2,7

Energy efficient control system for humidification system

Energy efficient control system


5615-9380€/humidification plant

2-3,5

Energy conservation measures in Overhead Travelling Cleaner (OHTC)

Energy conservation measures

5,3-5,8 MWh/year/OHTC 140-750€ OHTC 0,5-2,5

Energy efficient blower fans for Overhead Travelling Cleaner (OHTC)

Energy efficient blower fans Fan systems 2 MWh/year/fan 77€/fan <1

Improving the Power Factor of the plant (Reduction of reactive power)

Improving the Power Factor 24,1 MWh/year/plant 2540€/plant 1,8

Replacement of ordinary 'V-Belts' by Cogged 'V-Belts'

Replacement of ordinary 'V-Belts' by Cogged 'V-Belts'

1,5 MWh/yar/belt 9,4€/belt <1



6 – Conclusions and Next Steps

The exercise resulting in this document allows the SET project team coordinated by

CITEVE to define textile processes and a list of energy efficiency measures, both

process specific and cross cutting, to be used in the SET project. Within these

efficiency measures, some newly developed technologies were also presented. The

amount of collected measures (105 process specific and 117 cross cutting) is far above

the targeted 60 of each.

The work performed during this task and the information collected and created are

very important for the upcoming project developments. The contents of this document

will be used in the development of ESET (Energy Saving and Efficiency Tool)

methodology and as guide of best practices for textile companies. Information

contained in this report is also expected to be used for training and dissemination

purposes at least throughout 2015 and 2016.




7 - Reference

[1] Hasanbeigi, A., 2010. “Energy-Efficiency Improvement Opportunities for the Textile

Industry”. Berkeley, CA: Lawrence Berkeley National Laboratory

[2] CITEVE, 2012, EFINERG Project, “Plano sectorial de melhoria da eficiência

energética em PME – Sector têxtil e do vestuário”

[3] ITMA 2015, “General Regulations and Index of Products”

[4] CITEVE, 2012, Competitividade Responsável Project, “Guia de boas práticas para a

eficiência energética no Setor Têxtil e do Vestuário”

[5] Renovare Project, 2007, “Guia de boas práticas de medidas de racionalização de

energia (URE) e energias renováveis (ER)”

[6] United Nations Industrial Development Organization (UNIDO), 1992. “Energy

Conservation in Textile Industry-Handy manual”


SET - Production Processes and Efficiency Measures

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