Steam boiler systems require high quality water to function safely and efficiently. Deaerators (DA’s) help to protect boilers from corrosion by removing dissolved gases from the feed water, and provide storage of clean, treated water for transfer to the boiler as needed.
Lockwood Products has over 75 years’ experience in the design, manufacturing, selling and servicing deaerators, feedwater systems, condensate return systems, vacuum and heat recovery systems, pumps and boiler room ancillary equipment.
Deaerators perform three basic functions:
How it works:
Spray Tray Type ST: This style uses two stages of deaeration – a spray nozzle and a tray section. The returned condensate and make-up water are sprayed into a tower column of pressurized steam, which increases surface area and rapidly heats the water to saturation temperature, so gases can escape. It falls through a series of trays, which further breaks up surface tension and releases the remaining traces of the dissolved gases.
Spray Scrubber Type SS: The spray scrubber type also uses two stages of deaeration – a spray nozzle and a scrubber section. The returned condensate and make-up water are sprayed into a column of pressurized steam, and then is collected into a dish and funneled into the scrubber section, which forces steam bubbles to further agitate and “scrub” the dissolved gases.
Atmospheric Type AD: These deaerators operate at atmospheric pressures, so the storage vessel is not pressurized. A common style is to have a single tank divided into two compartments – a pre-heated surge compartment and a deaerating compartment. The surge compartment includes a steam sparge heater to pre-heat the water to 180°F. The water is then pumped through a heat exchanger which, because the water is under pressure, can be heated to approximately 220°F. This water is sprayed into the deaeration compartment via a spray nozzle. Because the deaeration section is at atmospheric pressure, the 220°F water will flash into steam, were the dissolved gases are separated and vented with the steam to atmosphere. The remaining water will be at saturated temperature, or 212°F.
Surge Tanks: If there are higher levels of returned condensate, a surge tank may be required. When returned condensate makes up 50% or more of the total boiler feedwater, surge tanks are recommended for the following reasons:
Boiler Feed Systems: If a boiler system operates on a 24/7 basis, a deaerator is recommended to maintain a continuous supply of high-quality water. However, if a boiler system is not in continuous operation, a simple boiler feed system may be considered as a lower-cost alternative.
Blowdown Separators: Boiler blowdown is a critical step in the process of protecting boiler systems. Regular blowdown helps to keep the boiler clean and prevents build up of particles and sludge in the bottom of the boiler pressure vessel. As the blowdown is under high pressure, it remains liquid until it is exposed to atmosphere, and “flashes” to steam. This flash steam is separated from the liquid blowdown water by means of a blowdown separator. Also, the water must be cooled below 140°F to prevent damage to drainage pipes.
Condensate Return Systems: In a typical steam system, steam condensate is considered a valuable commodity, not to be wasted. As steam gives off it’s heat energy, it changes into the liquid phase called condensate. This condensate is pure, clean, heated water, and by returning it to the boiler room, users can save a considerable amount of money in fuel, water and chemicals by returning a much condensate as possible back into the system.
Pumps and Pump Skids: Lockwood maintains an inventory of various types of pumps – centrifugal, turbine, and multi-stage vertical pumps, and others. With a full engineering team, Lockwood can design, and manufacture pumps skid for a wide variety of applications. Pump skids typically include the pumps mounted on a stand, with the connecting suction and discharge piping and trim components, and a control panel that can be integrated into a customer’s facility or system.
Parts: Lockwood stocks a wide variety of replacement parts for their systems, and for boiler rooms in general. These include, but are not limited to the following:
Please contact us for further information on Lockwood Products.