Condensate pumps are used in low pressure heating systems to collect and quickly return condensate to the boiler feed unit. Their pumping action is controlled by the water level in the receiver.
Condensate is returned to the vacuum receiver through the return inlet. When the receiver water level reaches a set point, the high level float switch starts the return pump(s), pumping the water from the receiver to the boiler feed system.
When vacuum in the lower receiver reaches a low preset level, a float switch operated makeup valve is activated to replenish the water supply. A temperature sensitive switch, wiered in parallel to the makeup circuit, also permits the addition of cooling water into the water supply.
Advantages of the Vacuum Return/System
- Fast, positive air removal. Air impairs the flow of steam and acts as an insulator, preventing efficient heat emission.
- Faster return of condensate to the boiler, minimizing heat loss.
- Vacuum provieds for freer flow of steam through the system. In most cases piping can be reduced at least one size over that required for comparable gravity return systems.
- Boiler can be operated at lower pressures, resulting in lower operating costs.
- Better control of systems where zoned temperature is requred.
- Vacuum pumps are a must for systems with long runs and central power plants.
BOILER FEED PUMPING SYSTEMS
Boiler feed pumps are used to pump and precisely control the condensate and makeup water required by the boiler(s) in low pressure steam applications. Pumping action is controlled by the fluid level in the boiler.
OPERATION-BOILER FEED OR MAKEUP PUMPS
Condensate is returned to the vacuum receiver through return inlet. When the water level switch in the boiler(s) reaches set low level, receiver return pump is turned on, pumping water from the receiver to the boiler.
On duplex or semi-duplex units, the water level switch may control an electric alternator in motor control circuit.
When water level in receiver reaches set low level, the reverse acting float switch in the receiver turns on the solenoid valve, allowin water to feed from the hurling tank to boiler feed receiver.
When vacuum in the lower receiver eraches a low preset level, the vacuum switch(es) actuates the requried motor controls, to turn on the vauum pump(s) which circulates water in the upper water tank.
If water in the upper water tank reaches a low preset level, a float switch operated makeup valve is activated to replenish the water supply. A temperature sensitive switch, wired in parallel to the makeup circuit, also permits the additon of cooling water into the water supply.
RECEIVERS AND HURLING/SEAL WATER TANKS
Cast iron, receivers are available from 45 to 840 gallon standard capacities. Welded, heavy duty, rust resistant, copper bearing steel receivers are available in two configurations: rectangular, or cylindrical. Capacities of standard rectagular steel receivers range from 29 to 1,000 gallons; cylindrical verstions from 49 to 1,000 gallons.
