Evaporators

Description

Chlorine is used in various industries for diversified applications. Chlorine is generally stored in liquid form in Ton containers or Cylinders. Generally, Chlorine gas withdrawal rates from these containers do not exceed the vaporization rate (normally it is 7 to 11 kgs/hr at around 28 deg celsius). Evaporators are used where large quantity of chlorine gas is required.

Working Principle

The Evaporator is divided into two Cubicles, the Inner Cubicle and the Outer Cubicle. Chlorine liquid is transferred directly from the source to the Inner Cubicle by container pressure.

This Inner Cubicle is immersed in a thermostat controlled hot water bath, which increases the temperature of chlorine causing it to boil and vaporize. Chlorine liquid enters the Inner Cubicle and maintains the required level necessary to meet the vaporization rate for gas demand. Automatically, a change in gas demand will cause the chlorine liquid level to adjust. The gas thus released is superheated as it passes through series of baffles while leaving the cubicle. Generally, a superheated gas is required to prevent re-liquification of chlorine in the process lines.

Installation

The Evaporator should be located close to the source of chlorine. The length of the chlorine gas and liquid chlorine pipelines should be as short as possible. All the safety equipments should be readily available and handy. The Plant should have provisions for exhausting chlorine gas, if a leak develops. Ideally a chlorine gas leak absorption system can be provided for gas leak evacuation and neutralization. It is recommended to fix a lifting device above the evaporator to remove the inner cubicle for ease in maintenance. Potable water [pH 7] should be provided to the System to prevent scale formation and increase the lifespan of Evaporator and Heaters.

Safety Features

The Outer Cubicle, which holds the hotwater, is protected against corrosion by two sacrificial anodes. These anodes being the most active material suffer corrosion, while the cubicle metal remains unaffected. In other words, the Outer Cubicle has Cathodic Protection. This Evaporator is designed to self adjust by maintaining the liquid Chlorine level in Inner Cubicle. The Evaporation rate is self-adjusting thereby preventing the build up of excessive pressure. An automatic or manual Shut-Off Valve and Pressure Relief Valve is also included for safe operation. A Temperature Controller is provided to automatically maintain the temperature of water in Outer Cubicle, so that vaporisation is continuous and thus ensuring constant supply of Chlorine Gas to process.

Proper water level in the Outer Cubicle is automatically controlled by a Water Level Controller, which automatically opens and closes a solenoid valve fixed in Evaporator water supply pipeline. Electric Heaters, Level Indicator, Temperature Gauge, Pressure Gauge form part of the accessories. We can provide additional accessories in Chlorine Liquid Pipeline, if required, like Expansion Chamber, Pressure Switches, Rupture Disc, Liquid Chlorine Supply Pipeline System with associated Manifolds, Valves etc

We can also provide additional accessories in Chlorine Gas Pipeline, if required, like Pressure Relief Valves, Rupture Disc, Pressure Switches, Shut-off Valve, Pressure Reducing Valve, Gas filter, Flow Control Valves, Flow meter, Pressure Gauges, Non Return Valves, Chlorine Gas Supply Pipeline System, Vent Pipeline, Chlorine Scrubbers, Chlorinators etc. This Evaporator is designed for reliability, safety and very little maintenance. This Evaporator can be made fully automatic or partially automatic depending upon the level of automation and sophistication required by the Client.