Chlorine Gas Leak Detector

Introduction

CHLORINE gas has many diversified uses, including water treatment and many other technical processes. However, chlorine gas is highly toxic and corrosive in nature. Therefore special precautions have to be taken in areas where chlorine is generated, stored or used.

If Plant Personnel are exposed even to low concentration of chlorine gas for an extended period it may affect grievously their respiratory system. Also, it corrodes costly plant machinery resulting in wastage of time and money, which is very much avoidable.

Chlordetect is an electronic detection system for chlorine gas and chlorine di-oxide in ambient air. Chlordetect monitors the contents of ambient air, detects leaks and warns personnel to take necessary preventive action.

This device will initiate a visual and audible alarm if the Threshold Limit Value (TLV) is exceeded. The TLV is the average concentration of the chlorine in ambient air for a normal 8-hour workday or 40 hour workweek to which nearly all workers may be exposed to day after day without adverse effects. Permissible TLV is 1 ppm or 3 mgms/cu.mt as per ACGIH Booklet on TLV 1984-85. However, this device can be set at more sensitive level of 0.5 ppm.

Working Principle

Chlordetect consists essentially of two parts,

• The Electrolyte sensor Cell and
• The Panel Box

The Electrolyte sensor is the gas-sensing Cell comprising two electrodes wrapped by a porous wick. The electrodes are partially immersed in the Electrolyte and kept constantly moist. In case of leaks, the chlorine gas in surrounding air comes in contact with the electrodes, an Electro-chemical reaction by de-polarization takes place causing a flow of electric current.

The electric current generated is proportional to the gas concentration in the air. An increase in the chlorine gas concentration is indicated in the Panel Box, which is equipped with an indicator of 0 to 5 ppm, or 0-10ppm or 0-50 ppm or 0-100 ppm chlorine. The desired level can be set by a potentiometer with a range of 0 to 5 ppm, or 0-10ppm or 0-50 ppm or 0-100 ppm chlorine.

During excess concentration of chlorine gas the leak detector will initiate a visual and audible alarm and operate an alarm relay. This alarm relay provides a voltage free contact for use of external Hooter or provide contacts for auto shut-off valves. When the gas concentration drops below the pre-set limit, the alarm contact will retain its former position.

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

If the level of chlorine in air exceeds the pre-set value the light emitting diode (LED) ALARM HORN will glow and another relay energized. The ALARM HORN is connected to the potential free output of this relay. The relay will remain energized until it is reset by means of a reset push button in the Panel Box. After having stopped the alarm and after the concentration has dropped below the preset limit the contact will be automatically in operating condition again.

The faultlight will glow when

• Electrolyte is empty
• Sensor Cell is dry
• Cable between Cell and Panel Box is disjointed.

Installation

Chlordetect consists essentially of two parts,

The Sensor Cell is located close to the place where the air is to be monitored. The Cell is mounted approximately between 300 mm to 400 mm from the floor since chlorine is heavier than air. The Cell should be fixed in a vertical position. The panel should be preferably installed in a chlorine free room.

The distance between Sensor Cell and Panel Box may be as per customer requirements. The distance may go upto 100metres using series of connection boxes and screened cable. Co-axial cable should be used between the connection box and the panel

Optional Arrangement

Chlordetect consists essentially of two parts,

In case of big Chlorination Plants, chlorine metering unit and chlorine containers are separately housed. In such areas, Chlorine Leak Detectors Panel with two sensors can also be provided. If required, separate alarm levels can be set for different rooms. Also, two Detector Cells in one room only, at different alarm levels (pre-alarm and main alarm) can be set, as per client's requirement. By providing working contacts it is possible to operate all kinds of ancillary equipments like alarm horns/Industrial Hooters, exhaust fans, automatic shut-off valves or comprehensive chlorine gas leak scrubbing/absorption systems.

Salient Features

• State of the art technology
• Instant response tshus detects gas leaks early
• Easy to install and maintain
• No cross sensitivity
• Very low operation costs
• Assured after sales support
• Long life span
• Economical