Automatic Changeover System

In order to have uninterrupted chlorine gas supply to chlorination system necessary manifolds.Motorised valves and control panel are provided. Chlorine tonner are connected to manifold in which pressure gauge and pressure switch are installed. Pressure gauge indicates the chlorine tonner pressure and pressure switch actuate the electrically operated ball valve. Pressure switch is set at 1.0 kg/cm² that means chlorine cylinder is getting empty.
Filled tonner connected to manifold. All tonners valve are kept opened so that manifolds are under pressurized condition. Switch on the auto change over panel and keep the selector switch in auto mode now as soon as panel is energized electrically operated valve manifold –I will open first. Even though manifold –ll is pressurized ,manifold –ll side valve will not operate due to inter lock system.
As plant is in operation, chlorine gas will be consumed and tonner pressure may be coming down.When pressure switch actuator and alarm will come and electrically operated ball valve on manifold –l will close and valve on manifold – ll will open simultaneously. This system will be in operation till chlorine gas pressure is above 1.0 kg/cm² at the manifold. During this period fresh filled cylinders may be connected to manifold and kept ready for operation. As explained earlier, chlorine pressure started going below 1.0 kg/cm², alarm will be there and manifold –l valve in opened thus the operation of auto change over system continues.
Note :- Kindly note that when the manifold pressure is 1.0 kg/cm² the chlorine tonner is not fully empty there will be at least one or two kg of chlorine will be available. It is not advisable to send chlorine cylinders for refilling with so much of chlorine left over. This left over chlorine shall be exhausted by keeping auto/manual selector switch in manual mode and operate corresponding push button stations and electrically operated valve can be opened. Keep the valve in open position till chlorine pressure comes to 0.2 kg/cm² . pressing “off” push button, valve will be closed. Similar way manifold –ll side shall be operated. During this operation no need of opening bypass valves. During manifold-ll is in operation fresh filled tonner may be connected to manifold –l and kept ready for auto operation.