University of Cairo

Faculty of Engineering

Chemical Engineering Department

April, 2009

Vibrating Screens

University of Cairo

Faculty of Engineering

Chemical Engineering Department

Vibrating Screens

Submitted to: Dr. Ahmed Sherif Eissa

Chemical Engineering Department Faculty of Engineering, University of Cairo

Prepared by: Group 16

Sec: 4 B.N.: Marwan Sallam 1 Marwa Samir 2 Marwa Adel 3 Marwa Mahmoud Ahmed 4 Mostafa Ahmed Saad Mostafa Mohsen Rafeek Mostafa Mohammed Maghawry Moataz Said Eissa Moataz Mohammed Atef Moataz Nabil Elsayed

5 6 7 8 9 10

April 29th, 2008

I

Table of Contents

Abstract II

List of Figures and Tables III

1. Introduction 1

2. Basic Principles and Theory of Operation 1

3. Advantages of Vibrating Screens 1

4. Equipment Details 2

4.1 Illustrated Figures 2

4.2 Description 3

4.3 Equipment Photos 4

4.4 Material of construction 5

5. Equipment Design 5

5.1 Design equations 5

5.2 Commercially Available Designs 5

6. Manufacturers 6

7. Cost Estimation 7

7.1 Using Cost Charts 7

7.2 Factors affecting the cost of vibrating screen 8

Summary 8

References 9

II

Abstract

The vibrating screen is a type of sieving equipment used in grading and separating

materials into various sizes to be used in different fields such as minerals and building

materials.

This report includes the technical description of the vibrating screen. It discusses the

basic principles and theory of operation of the vibrating screen, detailed description of the

equipment and the equations governing the variables of vibrating screen showing all the

mechanical parts of the vibrating screen. It also discusses the approximate cost of the

vibrating screen and it shows some of the famous manufacturers of the equipment.

III

List of Figures

Figure 1: Side elevation as embodied in an inclined vibrating screen 2

Figure 2 : End elevation of the separator 2

Figure 3 : Three pictures showing vibrating screen 4

Figure 4 : Chart of Cost vs. Screen area with material adjustment factors 7

IV

List of Tables

Table 1: Parts name of the vibrating screens 4

Table 2: Standarized designs of vibrating screens 5

Table 3: List of famous manufacturers 6

Table 4: Chemical engineering plant cost index 7

Table 5: Annual index 7

Table 6: Cost table of custom material of construction 8

1

1. Introduction

The vibrating screen is a type of sieving equipment used to separate materials into various

sizes for further processing, or far end use, depending on your need.

They are mainly used for grading and screening materials in the following fields: coal

dressing, metallurgy, mines, building materials, transportation, chemical industries, smelting

and many other fields.

The material is separated by passing it through a vibrating screen box which has a

number of different sized screens, or meshes, which the material falls through like a sieve.

The material falls onto attached conveyors which stock pile the end product. The end

products can then be used in the building and construction industries.

2. Basic Principles and Theory of Operation

The vibrating screen consists of screen box, supporting device, vibration exciter,

transmission part, etc. The barrel-type vibration exciter is installed in the middle part of the

machine. During normal operation, the vibration of exciter will drive the screen mesh fixed

on the screen box vibrate, and then materials will be screened. The big and small materials

fall from the upper side and lower side of the screen to get them separated [1].

Amplitude or stroke adjustment provides vertical motion and the material which being

screened loses some of its particles that depends on size and nature of these particles.

Frequency or speed adjustment is directly related to a lower stroke with high speed or to a

greater stroke with low speed. The slope of the screen governs the speed of the material flow

Also direction of rotation controls the direction of flow. Maximum separation efficiency and

high capacity production are reached if proper rotation is selected [1].

3. Advantages of Vibrating Screens

1. Simple and dependable Eccentric type system.

2. High screening capacity.

3. High durability.

4. No transmission of screen panels.

5. Ready changing of screen plates.

6. Rigid and vibrating resistance screen body.

2

4. Equipment Details

4.1 Illustrated Figures

Figure 1: Side elevation as embodied in an inclined vibrating screen [2].

Figure 2: End elevation of the separator[2].

3

4.2 Description:

A conventionally constructer rectangular separator screen 1, figs 1 and 2 is held

between the parallel side walls 2 of an upper vibrating frame 3. The screen proper is secured

within the frame 3 by multiple turnbuckle means 4 accessible at the two side of the frame 3.

The vibration frame 3 is inclined, as shown, and is equipped at its upper end with a material

input chute 5, the lower discharge end of the frame 3 being indicated by the numeral 6. The

space 7 beneath the screen separator is unobstructed so that a conveyor or other collector

means an occupy this space and receive material passing through the vibrating screen.

The upper frame 3 carries depending divergent legs 8 resting on coil spring vibration

support 9, in turn mounted on a relatively stationary base frame or bed 10, as illustrated. in

this manner, the vibration frame 3 with its separator screen 1 is bodily and floatingly

supported on the spring means 9 for vibratory motion.

The vibration motor means comprise a pair of counter-rotating conventional vibration

motors 11 mounted on the exterior of the opposite side walls 2 of vibration frame 3. By virtue

of this external side mounting ,the two motors 11 are immediately accessible for adjustment ,

repair or replacement .Each motor 11 is attached by a suitable fastener means at 12 to a

motor mounting plate 13 having apertured end extensions 14. A coacting two-part motor

mount 15 for each vibrating motor 11 consists of a center disc 16 having an annular marginal

step groove 17. Surrounding the disc 16 in spaced concentration relation therto is an L-cross

sections ring 18. The disc 16 and ring 18 are preferably welded to adjacent side wall 2.

An annular T-cross section passage 20 is created between the two elements 16 and 18

for the reception of T-bolts 21, whose shanks are received through aperture 22 in extensions

14. The T-bolt shanks can travel in either direction through annular passage 20 when their

locking nuts 23 are released. The locking nuts 23 for T-bolts 21 engage the exterior face of

plate 11. By loosening the nuts 23 slightly, each vibration motor 11 can be bodily and

rotationally adjusted relative to the side wall 2 through a full 360 degrees in a plane parallel

to the side wall 2 and parallel to the axis of the motor armature shaft. Each vibration motor

can be securely locked in any selected adjusted position by tightening the nuts 23. The

rotational adjustment of each motor 11 around the circumference of the ring 18 changes the

angle of the motor armature of the rotation axis [2].

4

No. Part name No. Part name No. Part name

1 Rectangular separator screen

9 Spring means 17 Annular marginal step groove

2 Parallel side walls. 10 Relatively stationary base frame or bed

18 Rings

3 Vibration frame 11 Motor 19 Circular cap

4 Turnbuckle means 12 Motor mounting plate 20 Annular T-cross section passage

5 Chute 13 Apertured end extension

21 T-bolts

6 Numeral 14 Coacting two-part motor mount

22 Aperture

7 The space 15 Center disc 23 Nuts

8 Divergent legs 16 Annular marginal step groove

24 The floor

Table 1: Parts name of the vibrating screens [2].

4.3 Equipment Photos

Figure 3: Three pictures showing vibrating screens [3].

5

4.4 Material of construction

Screens may simply consist of parallel metal bars but more often they will take the

form of a perforated metal plate, woven wire cloth or fabric (such as silk). Commonly used

metals are steel, stainless steel, copper, etc…

5. Equipment Design

Design of vibrating screens depend on three major factors which are mesh sizes, aperture

and open area. The factors can be estimated by determining the flow rate and its properties

such as screen analysis of the feed and the desired product. Design parameters can be divided

into basic and tables of commercially available models.

5.1 Design equations

F= D+B F.Xf = D.XD + B.XB D/F = (Xf-XB) / (XD-XB) B/F = (XD-XF) / (XD-XB)

E � D. XD. B�1 XB�

F. XF. F�1 XF�

E ��Xf XB� �XD XF� �1 XB�. XD

�XD XB� 2 �1 XF�. XF

5.2 Commercially Available Designs:

Model Screen size

(mm) No. of Layer

Screen mesh (mm)

Max. feed size

(mm)

Handling capacity

(t/h)

Motor power (kW)

Vibrating frequency

(r/min)

Double swing (mm)

2YZS1237 3700×1200 2 3-100 400 10-80 11 750-950 5-9 3YZS1237 3700×1200 3 3-100 400 10-80 11 750-950 5-9 2YZS1548 4800×1500 2 3-100 400 30-200 15 750-950 5-9 3YZS1548 4800×1500 3 3-100 400 30-200 15 750-950 5-9 2YZS1848 4800×1800 2 3-100 400 50-250 18.5 750-950 5-9 3YZS1848 4800×1800 3 3-100 400 50-250 18.5 750-950 5-9 4YZS1848 4800×1800 4 3-100 400 50-250 18.5 750-950 5-9 2YZS1860 6000×1800 2 3-100 400 65-586 22 750-950 5-9 3YZS1860 6000×1800 3 3-100 400 65-586 22 750-950 5-9 4YZS1860 6000×1800 4 3-100 400 65-586 30 750-950 5-9 2YZS2160 6000×2100 2 3-100 400 81-720 22 700-900 5-9 3YZS2160 6000×2100 3 3-100 400 81-720 30 700-900 5-9 4YZS2160 6000×2100 4 3-100 400 81-720 30 700-900 5-9 2YZS2460 6000×2400 2 3-150 400 100-810 30 700-900 5-9 3YZS2460 6000×2400 3 3-150 400 100-810 37 700-900 5-9 4YZS2460 6000×2400 4 3-150 400 100-810 37 700-900 5-9

Table 2: Standarized designs of vibrating screens[4].

6

Nomenclature

If we take the model 2YZS1237 for example,

2 Number of layers. Y The letter refers to the circular motion.

ZS They are specific for each company i.e. these letters are for Henan Liming Road & Bridge Heavy Industry Co., while they are replaced by 'K' in Shanghai Zenith Electric Power Equipment Co., so it differs from one company to another.

1237 Stands for the screen dimensions, mm = (1200x3700) and so on for the other models.

6. Manufacturers

Seller-Manufacturer Anping Kaibo machinery limited co., China

Seller-Manufacturer China NanChang ChangJiang Minning machinery co., China

Seller-Manufacturer Anping Yuzhihao Wiremesh products factory, China

Seller-Manufacturer Shanghai Shibang machinery co. LTD, China

Seller-Manufacturer Shanghai Zenith co., China

Seller-Manufacturer Hongchdaoda co., China

Seller-Manufacturer Zhengzhou Yifan machinery cooperation LTD, China

Seller-Manufacturer Henan Liming Road and Bridge Heavy Industry Co., China

Seller-Manufacturer Shanghai Zenith Power Equipment co., China

Seller-Manufacturer Lutai International Trade Department, China

Seller-Manufacturer Henan Dahua Minning machinery co. LTD, China

Seller-Manufacturer Yusheng company, China

Manufacturer Rotex, Inc., Ohio , US

Manufacturer Triple/s Dynamics, Texas, US

Seller-Manufacturer Won Duck Industrial Machinerty Co., Ltd, South Korea

Seller-Manufacturer Foladsaza-e Almanabad Co, ltd, Iran

Seller-Manufacturer VIBRA Maschinenfabrik Schultheis GmbH & Co. KG, Germany

Manufacturer KG Mogensen GmbH & Co, germany

Seller-Manufacturer Pioneer Weld and Weaves Pvt Ltd, India

Table 3: list of famous manufacturers[5],[6],[10],[11],[12].

7

7. Cost Estimation

7.1 Using cost charts

Figure 4: Chart of Cost vs. Screen area with material adjustment factors [7].

Table 4: Chemical engineering equipment cost index [9].

Table 5: Annual index [9].

(1957-59 = 100) Jan. ’09 Dec. ’08 Jan. ’08

Prelim. Final Final Equipment 642.4 654.3 632.7

Annual Index 2001 = 394.3 2002 = 395.6 2003 = 402.0 2004 = 444.2 2005 = 468.2 2006 = 499.6 2007 = 525.4 2008 = 575.4

8

7.2 Factors affecting the cost of vibrating screen

1- Capacity, where bigger ton per hour needed equal bigger wider screen box needed,

bigger shafts, bigger bearings, bigger slide plates, more steel to build and more safety factor.

2- Type of screen. (single, double, triple deck), where bigger vibrating screen require

more engineering knowledge to create structure.

3- Material of construction.

4- Deck area.

5- Horizontal or flat screens are generally costly to buy, more costly to run and more

costly to maintain.

Price Material of cloth wire Material of construction Deck area Screen type

18700$ Medium carbon steel wire Carbon steel 32 ft2 1- deck medium

20600$ Medium carbon steel wire Carbon steel 32 ft2 3- deck

23200$ Medium carbon steel wire Stainless steel 32 ft2 1- deck medium 33200$ Medium carbon steel wire Nickel alloy 32 ft2 1- deck medium 19900$ Medium carbon steel wire Carbon steel 50 ft2 1- deck medium 18800$ Heavy carbon steel wire Carbon steel 32 ft2 1- deck medium

Table 6: Cost table of custom material of construction [8].

Summary

The vibrating screen is a type of sieving equipment of high capacity and high

efficiency. It adjusts the amplitude by tube-shaped violent vibration screen of eccentric shaft

and eccentric blocks. The body moves like a circle, in order to make the materials screened. It

is widely used for grading and screening materials in the following fields: minerals, mines,

building materials, water conservancy and hydropower, transportation, chemical industry,

smelting and many other fields.

It features long flowing line, many screening specifications, strong violent vibration

force, high screening efficiency, small vibrating noises, firm and durable construction,

convenient maintenance and safe operation.

9

References

[1] http://www.break-day.com/en/vibrating-screen.html, cited in December 2008

[2] United States Patent No. 4274953 , June 23rd, 1981

[3] Shangahai Shibang Machinery Co., Ltd, http://www.sbmchina.com

[4] Henan Liming Road & Bridge Heavy Industry Co., Ltd, http://www.vibratingscreen.cn

[5] http://www.tradeegypt.com, cited in December 2008

[6] William D. Robinson, The Solid Waste Handbook, 1986, Pg460

[7] Max S. Peters, PLANT DESIGN AND ECONOMICS FOR CHEMICAL ENGINEERS 5Ed., 2002, Pg865

[8] http://www.matche.com, cited in December 2008

[9] http://www.che.com/business_and_economics/economic_indicators.html/,cited in April 2009

[10] http://www.laxmi-group.com,cited in April 2009

[11] http://www.industrystock.com, cited in April 2009

[12] http://www.made-in-china.com, Cited in April 2009