Disinfection of Drinking Water - Evaporation Technologies

*Evaporators Types and Designevaporator will suffer corrosion and supply the
Evaporation is an operation used to remove a liquidelectrical current needed to protect the structure.
from a solution, suspension, or emulsion by boiling offSAFE & SELF ADJUSTABLE CAPACITY
some of the liquid. It is thus a thermal separation, orEvaporator cannot fill with liquid to build excessive
thermal concentration, process. The evaporationpressure because its liquid level is self-adjusting. An
process is one that starts with a liquid product andautomatic shut-off and pressure reducing valve is
ends up with a more concentrated, but still liquid andincluded. A water temperature control thermostat
still pump-able concentrate as the main product fromand contacts for low water temperature alarm are
the process. During the design of evaporation plantsalso included. Other devices, as optional are high
Legal regulations, materials of construction andwater temperature alarm switch; a gas temperature
surface finishes,product's heat sensitivity, viscositygauge on the instrument panel; and a low water
and flow properties, foaming tendency, fouling andalarm actuated by a level probe.
precipitation, boiling behavior,costs for operation andBecause the evaporation rate is self-adjusting, the
maintenance,operating media,Site conditions etc.,proper liquid level is always maintained in the gas
have to be considered.There are differentchamber. The proper water bath level is maintained
evaporator types like Electrically heated, circulatingby a make-up-water flow meter with a manual
hot water vapouriser.control valve. Or, an automatic make-up-water level
ELECTRICALLY HEATED EVAPORATORSsystem is optional, Level probes in this
CAPACITIES UPTO 200 Kg/hr E-205resistance-type system open and close a solenoid
For Chlorine, also used for Sulfur Dioxide or Ammoniavalve to maintain the proper water-bath level.
GENERAL Electrically heated evaporators are used toRELIABLE OPERATION FULLY AUTOMATIC
convert liquid chlorine as specified into gaseous state.This is a water immersed-tank heat exchanger
The unit has adequate controls and safety functions.specifically designed to evaporate liquid chlorine. Sulfur
Chlorine is available in liquid form but is generallydioxide of ammonia. Heat from a hot water bath
utilized as a gas. Chlorine gas is normally withdrawnconverts liquid to gas. immersion type electric heaters
directly from containers when withdrawal rates dosupply the heat. The evaporator is designed for
not exceed the container vaporization rate. If a largesafety. It requires minimum maintenance. With several
quantity of chlorine gas is required, Chlorineoptions, operation can be fully automatic.
evaporators are used.Power Characteristics: 400-440 V. 3 phase, 50/60Hz
OPERATING PRINCIPLE* Dimensions: Dimension drawing numbers same as
Liquid chlorine is transferred from its source to themodel numbers with prefix "DM".
evaporator chamber by container pressure.* Installation: Installation drawing numbers same as
This chamber is immersed in a controlled heatedmodel numbers with prefix "IN".
water bath, which increases the temperature of theMaterials of construction
liquid, causing it to boil. Liquid enters the chamber and* Cabinet: Fiberglass reinforced
maintains the required liquid level necessary to meet* Water chamber: Steel
the vaporization rate for the gas demand. A change* Vapourizing chamber: Steel
in gas demand will cause the chlorine liquid level toAccessories
adjust. The gas released, rises through baffles andAutomatic water level control
superheated as it leaves the chamber. A superheatedImmersion heater contractor
gas is required to prevent gas reliquefaction inLiquid lines
process piping.Gas lines
INSTALLATIONGas pressure reducing and shut-off valve
Location- The evaporator should be located close toCathodic protection in water chamber
the source if possible. The length of liquid and gasElectric control panel
lines should be kept to a minimum. Container roomOrdering information
with provisions for exhausting gas, if a leak develops,Model number
is ideal. A lifting device above the evaporator isMedium to be vapourized
recommended for servicing the chamber.Capacity (kg/h)
CATHODIC PROTECTIONAccessories-required and optional
The water wetted surfaces of the evaporator areInstallation and service
protected against corrosion by two sacrificial anodes.Specialized technicians are prepared to install and
The anodes being the most active metal in theservice this and associated equipment.