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 CIRCULATING HOT WATER BATH VAPOURIZER CH-01
For Chlorine, Sulphur Dioxide and Ammonia
HOT WATER BATH VAPOURIZER
The design & manufacture of Vaporizer meets Chlorine Institute recommendations for liquid vapourization using Hot water. The liquid is inside the tube and the heating media `Hot water' is outside the tube. The vapourizer design pressure of 300 lbs meets Chlorine Institute Recommendations with corrosion allowance of 3 mm on chlorine side and 1.5 mm on water side.
Series CH-01 Vapourizer is of heavy duty construction. The internal and external surface of the vapourizing chamber can be easily inspected during servicing which is an unique feature of the design. Ease of cleaning is an added advantage to remove the sediments. CH-01 can be easily cleaned by removing the top bolt. Suction trap has a sacrificial chamber provided at the gas outlet which protects the main body from corrosion attack.
The water chamber has nozzle connections for hot water inlet, water outlet, Temperature indicator, Temperature controller and drain. Insulation on shell must be done by the client at site.
TO PLACE THE SYSTEM IN OPERATION
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1. |
Open water valve (12) |
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2. |
Allow vapourizer to warm, admit liquid slowly by opening the valve to vapourizer. Liquid flows due to the gas pressure prevailing in the container. |
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3. |
Observe vapour pressure gauge(1a) to come in line with liquid pressure gauge (1) |
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4. |
Open valve (6) |
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5. |
The pressure regulating valve (10) is factory set to reduce the gas pressure. |
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6. |
Operate the flow control valve (11) to control the gas flow |
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7. |
Interlock
Low water flow switch(15) and Temperature controller(16) is interlocked to the automatic shut of valve on gas line (5) to prevent liquid flooding in the absence /failure of heating media. |
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8. |
Observation
Observe the temperature on gauge. It must read above 4 deg.C than the ambient. This superheat prevents reliquefaction of gas in down stream of vapourizer gas line. It also indicates the healthy condition of vapourizer. If the superheat reduces less than 2 deg.C it indicates the fouling has occurred in the liquid chamber of vapourizer demanding cleaning of the internal surface. |
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TO SHUT DOWN THE SYSTEM |
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1. |
For Regular shut down operation close the liquid valve to the vapourizer and completely allow the gas to be consumed. Make sure the pressure gauge (1a) falls to `0' indicating the gas empty in vapourizer. |
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2. |
Alternate shut down
During emergency or intermittent operation sudden gas stoppage may be required. During this period close the gas line valve (6) but keep all the liquid line valves open. The pressure balances so that the vapourizer gas phase remains equal to the container gas pressure. |
OPERATING PRINCIPLE
In operation, liquid is introduced through liquid inlet which is connected to the bottom of the vapourizer tube by a dip pipe. Here the liquid rises to contact sufficient surface to meet the vapour demand rate. After equilibrium is reached vapourizer operates at essentially on container pressure.
As gas demand reduces, vapour pressure at the vapourizer raises thus reducing the inflow of liquid feed. On sudden shut down of gas valve, liquid would be forced out of vapourizing chamber back to the container.
With evaporation, the vapour rises through the vapour baffle to the super heating chamber, enters the suction trap and leaves through the gas outlet. Suction trap collects moisture and prevents such moisture from corroding vapourizer chamber. Since suction trap is not a pressure part, it can be severely corroded without impairing operation or safety.
Depending on the vapourizer capacity, type of liquid to be vapourized and hot water temperature available (minimum 65 deg.C), the hot water flow rate required for the vapourization can be calculated on case to case basis.
System Safety interlocks and alarms
alarms
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Liquid chlorine pressure high
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Chlorine gas pressure high
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Vapourizer water bath temperature low
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Vapourizer water bath temperature high
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Hot water low flow
INTERLOCKS
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Low temperature of hot water bath and low flow of hot water condition is interlocked with chlorine gas line auto shut off valve.
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High pressure on chlorine gas line is interlocked with waterline auto shut off valve.
MATERIALS OF CONSTRUCTION OF VAPOURIZER
LIQUID SIDE (Vapourizing side) |
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Tube |
ASTM A106 Gr.B |
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Flanges |
ASTM A105 |
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Dip pipe |
ASTM A106 Gr.B |
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Suction trap |
ASTM A106 Gr.B |
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Gaskets |
Lead / PTFE |
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WATER SIDE |
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Shell |
IS 2062 / IS 1239 Heavy |
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Flanges |
IS 2062 |
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Gasket |
Asbestos / PTFE |
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DESIGN PARAMETERS –Vapourizing chamber |
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Design Temperature |
120 deg.C (250 deg.F) |
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Design Pressure |
64.6 Kg/cm2 (920 psig) |
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DESIGN PARAMETERS - Water chamber |
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Design pressure |
5 Kg/cm2 |
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HYDRAULIC TEST PRESSURE |
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Liquid side |
102 Kg/cm2(1450 psig) |
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Water side |
10 Kg/cm2 |
CAUTION
Do not trap liquid in vapourizer by closing liquid and gas valves
TYPICAL SCHEME DRAWING 
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VAPOURIZER WITH FLOW CONTROL, MEASUREMENT AND REQUIRED SAFETY INTERLOCKS |
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1,1A,1B |
PRESSURE INDICATOR |
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2. |
EXPANSION CHAMBER WITH RUPTURE DISC AND PRESSURE SWITCH |
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3. |
VAPOURIZER |
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4. |
TEMPERATURE GAUGE |
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5. |
GAS LINE AUTO SHUT OFF VALVE |
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6, 6A |
BALL VALVE |
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7. |
GAS VENT VALVE |
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8. |
GAS FILTER |
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9. |
GAS PRESSURE RELIEF VALVE |
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10. |
PRESSURE REDUCING VALVE |
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11. |
FLOW CONTROL VALVE |
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12, 12A |
GLOBE VALVE |
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13. |
STRAINER |
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14. |
AUTO SHUT OFF VALVE (HOT WATER LINE) |
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15. |
FLOW SWITCH |
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16. |
THERMO COUPLE WITH THERMOWELL |
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17. |
CONTROL PANEL |
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18. |
CATHODIC PROTECTION FACILITY |
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19. |
CHLORINE GAS FLOW TRANSMITTER |
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