12272a- Evaporator for Zero Liquid Discharge Effluent (Capacity 500 kg per hr)

8/7/2019 12272a- Evaporator for Zero Liquid Discharge Effluent (Capacity 500 kg per hr)

1/10

The salient features of the system shall be as follows:

6. The system shall be operator friendly and shall be provided withfair degree of PLC based automation. The layout of the plant isvery simple and ensures that the human movement duringoperations shall be minimum and shall be restricted to the

ground floor only.

7. All the Calendria areForced Circulation type and not Falling filmtype. As, we, by design, maintain a threshold velocity of flow inthe tubes, the crystallization and deposition on the walls of thetubes is minimized. (Not so in falling film Calendria). This ensureslong,trouble free operation of Evaporator.

8. To give additional protection from corrosion, the Calendriatubes are of SS 316 Ti.The temperature profileof the systemissuch that thecorrosion is minimized. All the Steam jackets of theCalendria shall be in SS 304.

9. The liquid contact parts shall be in SS 316 L.10.The offered system With Thermo recompressor ensures

optimum Steam Consumption and hence lowers the operatingcost.

11.The condensate generated from our evaporator shall be clearwith TDS of 150 ppm or less. and hence can be reused backinto the process, Boiler, Cooling Tower after proper treatment.

I. TECHNICAL PARAMETERS / DESIGN BASIS :

1 System offered. Double Effect, Forced Circulation type Evaporation

system.

2 Operating hours. 8-10 hrs .

3 Feed Composition. Effluent From R.O. Rejects./Softener Reject .

4 Plant capacity.

Feed Rate to MEE.

10 cum/day.

500 Kg /hr.

5 % solids in Feed. 4.7 % w/w.

6 Evaporation Capacity. 500 kg/hr maximum by design.

7 Salts From Centrifuge. 26 kg/hr maximum @8%- 10 % moisture content.

8 Material of

construction.

Contact parts SS 316 L.

Evaporator Calandria Tubes SS 316 Ti .

(To Protect From Chloride Stress Corrosion)

Non Contact parts SS 304.


2/10

II.SCOPE OF SUPPLY

Sr

No

Description of Item

1 Balance tank .1 No

This tank of 50 lit. shall be supplied along with a float valve to receive thefeed solution and to keep the level in the tank. One no limit switch shall beprovided to the tank, which shall ensure that in an event of feed supplyfailure water flow shall be started by activation of solenoid valve on processwater line. The tank shall be constructed in SS 316L .

2 Online Duplex strainer1NoAn Online duplex type strainer of SS 316L shall be provided for filtering thefeed to the evaporator.


3/10

3 Feed Pump with motor.1 NoFeed pump shall be provided with mechanical seal and shall be coupleddirectly with a squirrel cage induction A.C. motor of suitable horsepower.

Type : Centrifugal.

MOC : SS 316.Drive : Squirrel cage induction motor.

4 Magnetic flow meter1 NoA magnetic flow meter with isolation valves shall be provided in the deliveryline of the feed pump for regulating the flow to the Evaporator.

5 Preheaters1 SetA set of two preheaters shall be provided to increase the temperature of thefeed solution equivalent to the evaporation temperature of Calendria I in theevaporation section. The purpose of the preheater is to provide the initialpreheating at cheaper cost, using the calendria chest vapours and each ofthe preheater is attached to one of the three calendria in Evaporationsection.Quantity : 2 Nos.

Type : Shell and tube type, Vapour in shell and liquid in tube.MOC: Contact Parts SS 316 L, Shell - SS 304, Tubes SS 316 Ti.

6 Evaporator Calendria2 Nos

The effluent shall be fed to the Calendria I.A typical Calendria shall consist ofstraight tubes welded to the tube sheets, one on the either side. The tubesshall be enclosed in SS 304 shell, which would act as a jacket for vapours.

The tubes shall be arranged in calculated number of passes of flow of liquidin order to minimize scaling of the salt. The top and the bottom tube sheetsshall be enclosed with domes. The shell shall be provided with outlet for non-condensable and Condensate.

Type : Forced Circulation type.MOC : Contact parts SS 316 L, Tubes SS 316 Ti , Shell SS 304.

7 Vapour Separators2 NosEach Calendria shall be provided with its own vapour separator SS316Lplaced in front of it. A typical separator shall be designed to impart thegreatest effect of separation of the liquid droplets from the vapours. Thevapour enters the separator through a tangential inlet and leaves theseparator from the top through an outlet provided.

The separator shall be provided with the following additional accessories.:Demister arrangement,1no sight glass and light glass, 1 set connections fordial thermometer, sensors and vacuum gauge, Level controller sensor(Diaphragm type).


4/10

8 Thermo Re-Compressor1 NoOne no. thermo compressor for the vapour shall be provided to compressand re- feed a part of the vapours generated in the first effect back to thefirst effect chest. Live steam shall be used for compressing the vapours. Thematerial of construction of the Thermo Re-compressor shall be SS 304.

9 Recirculation Pumps with motors1 SetOne Set of recirculation pumps for each Calendria to recycle the contentsofCalandria through the separators. The pumps shall be of provided withexternally Water cooled double mechanical seals.

Type : Centrifugal, Open impeller type.MOC : Contact Parts - SS 316 , Drive : Squirrel cage induction

motor.10 Product Pump with motor.

1 NoThe construction of the product pump shall be similar to that of the Feedpump.

11 Condensate pump with motor1 NoCentrifugal pump shall be provided to extract the condensate generated inthe process out. The description of the pump shall remain the same as theproduct pumps.

Type : Centrifugal.MOC : Contact Parts SS 304.Drive : Squirrel cage induction motor.

12 Vacuum Pump with motor1 No+1No Stand ByA water ring vacuum pump shall be supplied along with the electrical motorthrough flexible coupling.The pump shall have a Cast iron body and a castiron rotor. The pump shall be selected to produce adequate vacuum in theplant during the operation.

Type : Water Ring type.MOC :Cast Iron.

13 Semi Barometric Condenser1 NoSemi Barometric condenser shall be provided to condense vapours from thesecond Effect. The barometric condenser has cascades in side a cylindricalshell. The vapours are fed from the bottom and water from cooling tower at

320

C is fed from the top in a counter current fashion.Type : Semi Barometric.MOC : Contact Parts SS 304.

14 Basket Centrifuges2 NosBasket Centrifuges shall be provided for filtration of the solids produced in

the Evaporator. The centrifuge shall be top open and shall be provided with aPolypropylene bag for filtration. The centrifuge shall have all the liquid


5/10

contact parts in SS 316L.

15 Filtrate Pump

1 NoA filtrate pump shall be provided with motor for Pumping the filtrate to theEvaporator. The pump shall be centrifugal pump with the description sameas feed pump.

16 Seal water cooling system1 Set

The vacuum pump discharge water along with the seal water for the pumpsshall be cooled in closed circuit using a PHE so that the water shall returnback to the vacuum pump / pump seals at required lower temperature. Thesystem shall consist of a Tank with a make up water line.

17 C.I.P. SystemA C.I.P. Solution of 4% Nitric Acid/3% Caustic Soda Shall be made inbalance tank (Item no 1), is circulated in first calendria for 3 hrs. The sameSolution is fed to remaining Calendrias for another 3 hrs. Finally used C.I.P.Solution fed back to ET.P.. This process is to be done once in week/fortnight. No extra Set is required for CIP.

18 Ducting, piping and fittings1 LotOne lot of Ducting, piping and fittings in SS 316 / SS 304/Carbon Steel shallbe provided complete with necessary pipes, bends, tees, valves, etc forinterconnection of various components to form an optimum and compactlayout. Cable Tray & Cable Tray Support shall be supplied.

19 Local instrumentation and indicators

1 Lot

The supply shall include the following indicators to be given for localmonitoring.

a) Temperature gauges / thermometers mounted on :Feed to Calendria I, product outlet.

b) Vacuum gauges ./Pressure gauges mounted on:Calendria I chest,Vapour separators in all effects.Main steam header.

20 Electrical Panel1 No

A Common Electrical control panel shall be provided in damp proofconstruction out of CRCA sheets of thickness 14/16 gauge and painted withsynthetic enamel paint. This panel shall be kept in Non flameproof area .Amimic diagram of the flow sheet of the plant shall be supplied printed onacrylic sheet. The panel shall be equipped with fuses, contactors, relays,sequential timer, The panel shall be pre-wired and tested before dispatch.


6/10

All the controls shall be PLC based.Following shall be the instrumentation provided :

a. Digital Indicator of vapor temperature in vapour separators , Chest of IEffect calendria.

b. Steam pressure controller based on thetemperature of I Effect chest. For the

thermocompressor.c. Variable speed drive for Feed pump.d. All vapour separators are provided with level

controllers.e. Magnetic flow meter for Feed line.

One lot of cables shall be supplied along with the panel.

21 Cooling Tower, Pumps ,Piping and accessories1SetA induced draft cooling tower shall be supplied for supplying the coolingwater to the barometric condenser of the Evaporator . The tower shall bemainly in FRP construction .

The cooling water from the Semi Barometric condenser shall be pumped fedback to the cooling tower by the following water extraction pump providedwith a single mechanical seal. The pump shall be in CI construction

22 Support Structure1 Set

The entire evaporator shall be placed in open on a prefabricated Red OxidePainted Carbon steel structure with platform and staircases. We shall givetotal drawings for the structure.


7/10

III. UTILITIES REQUIRED:

Electricity -3 Phase, 415 V , 50 Hz.Evaporator.

Connected Load .

Consumed .

32 Kw. (With Utilities)

27 Kw.

Steam Dry & saturated at 7 bar g .Evaporator.

175 Kg/hr. max. @ 500 Kg./hr.Evaporation

Cooling Water - @ 320C with max. hardness of100 ppm as

CaCO3. T of 70C.

Quantity reqd.

Make up water.

Cooling Tower.

14 cum/hr.

0.12 cum/hr.

30 TR.

Dry Instrument Air @ 5 bar 7 CFM. Max.

Wash Water As and when required.

Utilities mentioned are with +/- 10% Tolerance.

VI. SPACE REQUIREDEvaporator

8 m L x 6 m W x 12 m H . May be kept in open.

/Shed.

Panel Room

4 m L X 4 m w x 3 m H. Should be provided with


8/10

AC.


9/10

ANNEXURE I

MAKES OF BOUGHT OUT ITEMS

Sr.No

Item Make

1. Pumps. Johnson /KSB.

2. Thermocompressor.

Croll Reynolds.

3. Major Panelcomponents.

Siemens.

4. Level controllers. Yokagawa./Siemens.

5. Magnetic Flowmeter.

ABB.

6. Vacuum pump. Prime Engineering.

7. Basket Centrifuge. Ace Make.

8. Motors. ABB./Crompton Greaves

9. Mechanical Seals. Sigma Seals./J.K.Seals.

10. Cables. Polycab.

11. PLC. ABB/Siemens.


10/10

ANNEXURE II

OPERATING COST FOR MULTIPLE EFFECT EVAPORATOR:

Sr.No.

Item.

1. Power Required 27 Kw X Rs.6/- per Unit of Kw.2. Steam Required 175 Kg/hr X Rs.2/- per Kg of Steam (CNG gas

As Fuel).3. Man Power Required (3 Skilled & 3 Unskilled labours) And C.I.P.

Chemicals.4. Miscellaneous.(Spare Parts Mainly Mechanical Seals of Pumps)

@ 5% of Capex./year.

12272a- Evaporator for Zero Liquid Discharge Effluent (Capacity 500 kg per hr)

Documents

Transcript of 12272a- Evaporator for Zero Liquid Discharge Effluent (Capacity 500 kg per hr)