|CHLORINE WITHDRAWAL FROM CONTAINERS
Chlorine is commonly available in upright position gas cylinders of ton containers set in a horizontal position.
Rate of withdrawal of Chlorine Gas from Ton Container.
Rate of discharge beyond the recommended value would cause reliquefaction of chlorine in the pipeline and cause malfunction of chlorine handling equipment.
When gas discharge from single ton container does not meet the requirements, two or more ton containers may be connected to a manifold.
Connecting more than four tonners to a manifold is not recommended as per IS:10553 (Part 2) 1983 clause 6.2
If a high rate of flow is required chlorine should be withdrawn as liquid and converted to gas by means of a vapourizer also known as evaporator.
LIST OF EQUIPMENTS AND CONTROLS FOR HANDLING CHLORINE
- Vapourizer Steam heated / Electrical heated type.
- Liquid & gas chlorine manifold for withdrawal of chlorine.
- Trunnion roller supports for mounting the container.
- Lifting beam with load indicator.
- Chlorine manifold valves.
- Ball valves of socket weld and flanged and connection with Hastalloy-C/Monel trim.
- Pressure regulating valve of chlorine gas/size from 15NB to 100NB. Capacity : 10-2500 Kg/hr.
- Auto shut off valve for automatic controls, 15NB to 100NB
- Flow control valves, 15NB to 100NB
- Flow meter (Rotameter type)
- Control instrument panel.
- Pressure relief Valves.
- Chlorine leak detector.
- Flexible copper connector to connect tonners.
- Yoke and Adopter for Tonner outlet.
- Chlorine Service pressure gauges.
- Chlorine Service pressure switches.
- Chlorine, gas filter to eradicate solid impurities in Cl2 gas.
FACTS & DETAILS YOU SHOULD KNOW
- Chlorine is bottled in compressed liquid form
- From 100 Kg. cylinder only gas can be drawn. Continuous gas supply from cylinders is 1 kg/hr at 27 deg.C. ambient.
- From tonner (900 kg. Capacity) chlorine gas can be drawn @13 Kg/hr at 27 deg. C ambient.
- Liquid chlorine can be drawn from tonners @ 300 Kg/hr.
- Manifold - One manifold is recommended to handle 4 Nos cylinders or tonners.
- To meet high chlorine gas flow rate requirements, Evaporators (Vapourizers) are used.
- Electrically heated constant water bath temperature vapourizers are used upto 300 Kg/hr. This type is expensive and consumes power at 10 KW/100 kg. of Chlorine vapourized.
- Steam heated vapourizers are economical and less expensive to operate. From 200 Kg/hr to 25000 Kg/hr various capacities can be provided. Steam consumed for vapourizing liquid chlorine to gaseous chlorine is 16Kg. steam per every 100 Kg. of chlorine vapourized. Properties of Chlorine - Atomic wt. 35.453 - Molecular weight 70.906 - dry gas density 3.029 gm/lit. at 0 deg. C. atm. Liquid chlorine density 1.468 gm/lit. at 0 deg . C. chlorine gas in non explosive and non flammable.
- Instruction and periodic drill on use of "Emergency Kit" is required.
- Instruction and periodic use of personnel protective aids, safety shower & eyewash baths, use of respiratory breathing apparatus to avoid inhalation of vapours of chlorine and direct contact with the liquid.
- Instruction to report to the proper authority about all equipment failures.
Gas masks should be available for handling emergencies with a full face mask, and with air supplied through a hose form a remote air source. This can be used in absence of compressed air breathing apparatus. Protective clothing is not required for performing routine plant operations. Resistant plastic or rubber gloves should be worn by personnel.
CHLORINE HAZARD AND MEDICAL ASPECTS
Chlorine gas is primarily a respiratory irritant. It is so intensely irritating that concentrations above three to five parts per million (by volume) in air are readily detectable by the normal person.
Chlorine is not a serious industrial hazard if workers are adequately instructed and supervised in proper means of handing the chemical
Emergency showers and eye-wash should be placed in convenient locations.
Oxygen has been found useful in the treatment of chlorine exposures. In most exposures, administration of 100 percent oxygen at atmospheric pressures has been found to be adequate.