Why the vacuum principle makes gas chlorination safe
In vacuum-type gas chlorination the chlorine leaves the cylinder under vacuum, not under pressure. Here is what happens if a line is damaged, and how the rooms of a chlorination plant are laid out.
Gas chlorine is still one of the most economical answers in disinfection. The real question is not the chlorine itself but how it travels inside the plant. In modern systems the answer is the vacuum principle.
Pressurised line versus vacuum line
In a pressurised system the gas fills the line from the cylinder to the injection point under pressure. A leak anywhere on that line means gas escaping into the room.
In a vacuum system a vacuum regulator is mounted directly on the cylinder valve. Gas is drawn by the vacuum created at the injector, so the pressure inside the line stays below atmospheric. If the line is damaged, gas does not escape — air is drawn in, the vacuum collapses and the regulator shuts the cylinder off.
The rooms of a chlorination plant
- Cylinder room: chlorine cylinders or containers, weighing system, automatic changeover units.
- Evaporator room: at higher capacities, the evaporator converting liquid chlorine to gas, with its safety equipment.
- Chlorinator room: vacuum regulator, dosing unit, injector and motive water line.
- Control and observation room: gas detectors, automation panel, observation window.
The second line of defence: the scrubber
The vacuum principle secures the line, but a leak at the cylinder itself remains possible. That is why the cylinder room is connected to a neutralisation (scrubber) system: when the gas detector senses a leak, room air is drawn to the scrubber by a fan and neutralised with caustic solution.
Three points often missed in maintenance
- Injector: the vacuum is created by the motive water flow. When the water pressure drops, dosing drops with it — check here first.
- Gaskets: renew the gasket at every cylinder change; a reused gasket is the most common source of leaks.
- Detector sensors: sensors have a limited life and must be calibrated and replaced at the manufacturer's intervals.
Let us work out your equipment list and room layout together — send us your flow and chlorine demand through the request form.
