WT.050.200.001.UA.IM.0814
50-200 EVAPORATOR FOR CHLORINE
28
EVOQUA
W3T98237
WARNING: TO AVOID DAMAGING THE INTERNAL PLASTIC COMPONENTS
OF THE CHLORINATOR, OR TO AVOID SEVERE PERSONAL INJURY CAUSED
BY THE RELEASE OF CHLORINE GAS, BE CERTAIN THAT NO LIQUID CHLO-
RINE EXISTS IN CHLORINATOR ROTAMETER TUBE. IF CHLORINE LIQUID
IS PRESENT IN THE ROTAMETER TUBE, IMMEDIATELY SHUT DOWN THE
EVAPORATOR BY FOLLOWING THE CYLINDER EVACUATION PROCEDURES
IN PARAGRAPH 3.2.3B. REFER TO SECTION 4 FOR CYLINDER CLEANING
INSTRUCTIONS.
The need for cylinder cleaning can also be determined by observing the
gas temperature gauge on the front panel next to the pressure gauge. The
gas temperature gauge will show a drop in gas temperature at a given pres-
sure and rate of withdrawal as impurities are deposited inside the chlorine
cylinder. With some experience, the operator can use this indication to
determine when the evaporator will need cleaning. As long as there are
no blockages or closed valves between the evaporator and the supply, the
pressure within the evaporator cylinder is the same as the pressure in the
tank car or ton container, which in turn is a function of the temperature
of the liquid chlorine in the tank car or ton container. By reading the pres-
sure gauge for the evaporator cylinder, a close approximation of the liquid
chlorine temperature can be obtained by referring to the temperature/
pressure scale on the face of this gauge.
After evaporation at this temperature, the chlorine will pick up heat during
its passage through the evaporator. The additional heat picked up is called
“Superheat”. The amount of superheat at a particular time is function of
the difference in temperatures between the water bath and the liquid
chlorine, the efficiency of heat transfer through the wall of the chlorine
cylinder and the rate of withdrawal of gaseous chlorine. The face of the
pressure gauge is graduated for pressure and the equilibrium (evaporat-
ing) temperature at that pressure. Using the gas temperature gauge, an
approximate value of superheat can be obtained by reading the pressure
and gas temperature gauge. For example, the pressure is 85 psi and tem-
perature is 87°F. Reference to the temperature scale on the pressure gauge
will show that the equilibrium (evaporating) temperature for a pressure
of 85 psi is 70°F. Since the actual gas temperature is 87°F, the superheat is
17°F. It will be observed that a decrease in the withdrawal rate will result
in an increase in superheat. Likewise, increasing the withdrawal rate will
result in a decrease in superheat.
In general, as long as there is some superheat, the evaporator is functioning
properly. By periodically recording the superheat at a given chlorine feed
rate and water bath temperature, the plant operator has an indication of
the condition of the inside of the chlorine cylinder. Contaminants in the
liquid chlorine tend to accumulate in the evaporator cylinder and deposit
on the inside wall, thus reducing heat transfer from the water bath. When
sufficient impurities have collected to result in insufficient heat transfer,
the superheat will have dropped close to zero and liquid chlorine will begin
!
Summary of Contents for Wallace&Tiernan 50-200 Series
Page 1: ...Series 50 200 Evaporator For Chlorine BOOK NO WT 050 200 001 UA IM 0814 W3T198237 ...
Page 2: ...SERIES 50 200 EVAPORATOR FOR CHLORINE BOOK NO WT 050 200 001 UA IM 0814 W3T198237 ...
Page 15: ...WT 050 200 001 UA IM 0814 50 200 EVAPORATOR FOR CHLORINE 4 EVOQUA W3T98237 ...
Page 75: ...WT 050 200 001 UA IM 0814 50 200 EVAPORATOR FOR CHLORINE 64 EVOQUA W3T98237 ...
Page 95: ...CHLORINE HANDLING MANUAL Cl2 BOOK NO WT 025 000 001 UA IM 0614 W3T98244 ...
