Coil-in Water Bath
The Vapouriser unit consists of a stainless steel coil, immersed in a hot water bath. Heaters are provided to heat the water. Water temperature is controlled by switching the heaters on and off, using thermostats. Water level is controlled by a float valve. Level can be seen in a level indicator. Water supply line with a strainer should be connected to it and this line should be open whenever the unit is in operation.
Liquid LPG enters the coil at bottom and gets vapourised as it travels through it and the LPG vapours leaves at the top.
A Solenoid Valve (SV) is provided at LPG inlet. The solenoid valve controls the liquid LPG supply to the vapouriser, depending upon vapour pressure and water temp.
The Pressure Switch (PS) is provided to sense the pressure in the vapour line downstream of the pressure regulator. Pressure in this line increases if the off take from the vaporizer reduces. PS will cut off power supply to the solenoid valve, if the pressure increases beyond the value set on the regulator, thus stopping liquid LPG supply to the vaporizer. When the pressure falls below set pressure, the PS will switch ON the SV and liquid LPG will start again. Thus the vaporizer caters to the varying load automatically.
A float valve is fitted at the end of the coil. If the LPG liquid enters the valve chamber, the float closes the incoming flow to the valve chamber, and stops liquid LPG from entering the system.
A thermostat controls the solenoid valve, sensing the water temperature and opens the solenoid valve only if the temperature is more than the value set on the thermostat. This ensures that liquid LPG is not supplied to the unit when the water temperature is not sufficient.
When off take from vaporizer is less than its rated capacity or stops completely, the water temp rises. When it reaches the value set on the thermostat, the power supply is cut off. This results in power saving.
A pop action safety relief valve is fitted at the vapour outlet of the vapouriser. If there is pressure build up in the coil in most unlikely situation, pressure will be relived.
The vaporizer unit is insulated from outside using glass wool with aluminium cladding. This reduces heat losses to atmosphere and also makes the unit touch safe.
Vapourisers of this design are manufactured with capacity of 50 to 750 kg/hr.