Heat Recovery Equipment
Used to preheat feedwater entering the boiler and to capture heat lost through boiler blowdown. Typically used on installations where boiler size, operating pressures or the amount of water make-up justify the purchase, installation and maintenance costs. A rule of thumb might be boiler units exceeding 100 hp and operating at 100 psi or more.
Economizers
A special type of heat exchanger that can be used to improve the efficiency of the overall system by 2% - 4% depending on fuel being burned, boiler size and operating conditions. The type of boiler and the overall boiler room layout dictate which style is used.
Blowdown Equipment
Used on continuous blowdown systems to capture heat from the blowdown and cool it to the point where it can be safely dumped to the sewer system. The heat is transferred to the make-up water, improving overall efficiency of the system.
Flash Tank Heat Exchanger
A boiler blowdown heat recovery system that also provides the benefit of flash steam to be reused in the plant.
Blowdown Separator
A special blowdown system which cools the bottom blowdown water, making it safe for discharge into the sewer system. Little or no heat recovery benefit due to the erratic flow of bottom blowdown.
Sample Cooler
Piece of equipment that cools samples of the boiler water so chemical tests can be performed.
Deaerators
Mechanical equipment used to remove oxygen and carbon dioxide from the feedwater, preventing costly corrosion in the boiler, steam lines, condensate lines and heat transfer equipment. May allow reduction in use of chemicals. The dearator provides an effective means for recovery of heat from boiler exhaust or flash steam. Also allows for recovery of condensate to reduce amount of make up water required. A tray deaerator is typically used in large plants, while a packed column or spay type deaerator is used for smaller boiler operations.
Feed Systems
A packaged feed system is used when conditions do not warrant the cost of a deaerator. The feed system preheats the boiler feedwater, reducing the amount of oxygen and carbon dioxide entering the boiler. This system will require more chemicals than a deaerator.
Pretreatment Equipment
A variety of filters and other equipment is available to remove impurities in the boiler feedwater. The type of equipment required is determined by a water analysis.
Surge Tanks
Tanks designed to accept condensate and make-up water before it goes into the deaerator. Used when there are intermittent peak loads of condensate that exceed the capacity of the deaerator, when there are varying pressures or temperatures in the condensate or when there is insufficient pressure for the condensate to enter the deaerator on its own.
Water Softener
Water softeners remove hardness in the water and prevent scale buildup on heat transfer surfaces, reducing the neat for chemical treatments used to control scale. Common softening systems include acolyte softening to remove calcium and magnesium, dealkalizers and reverse osmosis used to remove dissolved solids in the make-up water.
Manual Shot Feeders
Chemical "pot type" feeder typically installed in small boiler plants on the discharge side of the boiler feed pump. This feeder is convenient and economical.
Chemical Feed System and Metering Pump
An automated system designed to feed chemicals into a boiler at a predetermined and controlled rate. Typically used for oxygen removal, pH adjustment or any chemicals for prevention of deposits or corrosion.
Flame Safeguard Equipment
Programming control on boilers designed to control and monitor start up and operation of the boiler. They also provide for shut down of the burner if the load demand is satisfied and for shut down and alarm in the event of a safety shut down situation. Solid state or micro processor controls are typically used on the boilers currently available and may include additional alarm and monitoring features and possible interface to energy management systems.
Stacks
Stacks are used to vent exhaust to the external environment. A wide number of stacks are available, and the type of equipment used, the fuel choice, the exhaust temperatures, building use and type of construction and specific characteristics of the job site information should be considered in selecting the type of stack to be used in the system.
O2 (Oxygen) Trim
These systems continuously monitor oxygen concentrations in the boiler flue gas and adjust the fuel to air ration to maintain the oxygen level at a set point. These will improve the efficiency of the operation by compensating for changes in ambient air temperature, barometric pressure, humidity and slight variations in fuel characteristics.