Water Systems
MPN Boilers can help you create a water management solution that will meet your exact requirements and minimize your expenses. We work with a variety of equipment manufacturers to select the best product for your needs and then help you manage the installation. After the installation, we can provide you prompt delivery of parts and service to keep your equipment running in the best possible condition and efficiency.
Water systems can include feedwater, deaerators, surge tanks, softeners, blowdown separators, blowdown heat recovery, chemical feed and boiler feed capabilities.
Deaerators
A deaerator is a device that is widely used for the removal of oxygen and other dissolved gases from the feedwater to steam-generating boilers. In particular, dissolved oxygen in boiler feedwaters will cause serious corrosion damage in steam systems by attaching to the walls of metal piping and other metallic equipment and forming oxides (rust). Dissolved carbon dioxide combines with water to form carbonic acid that causes further corrosion. Most deaerators are designed to remove oxygen down to levels of 7 ppb by weight (0.005 cm³/L) or less as well as essentially eliminating carbon dioxide.
There are two basic types of deaerators, the tray-type and the spray-type:
The tray-type (also called the cascade-type) includes a vertical domed deaeration section mounted on top of a horizontal cylindrical vessel which serves as the deaerated boiler feedwater storage tank. This unit can handle severe load swings, varying inlet water temperatures and changing operating pressures while maintaining deaeration efficiency.
In the tray type unit, water is sprayed into a pressurized steam atmosphere (first stage deaeration) in order to preheat and partially deaerate the incoming water. The water then cascades down through a series of stainless steel trays, while the countercurrent steam flow scrubs the remaining traces of oxygen out of the water. The steam acts as a carrier gas, to expel the removed oxygen out the vent. The deaerated water then falls into the horizontal storage section and is ready for use by the boiler, at saturated temperature and with oxygen levels at .005 cc/liter.
The spray-type consists only of a horizontal (or vertical) cylindrical vessel which serves as both the deaeration section and the boiler feedwater storage tank. It is best used for fairly stable loads and constant water inlet temperatures. It is the most economically priced unit in the 7,000 #/hr and higher flow range.
In the spray type unit, water is sprayed into a pressurized steam atmosphere (first stage deaeration) in order to preheat and partially deaerate the incoming water. The water is then directed to the scrubber (second stage deaeration) where the water is violently scrubbed to remove the final traces of oxygen. The steam acts as a carrier gas, to expel the removed oxygen out the vent. The deaerated water is then ready for use by the boiler, at saturated temperature and with oxygen
Surge Tank
A surge tank is a storage reservoir at the downstream end of a closed feeder to absorb sudden rises of pressure, as well as to quickly provide extra water during a brief drop in pressure. Because condensate return volume is largely unpredictable, a surge tank provides a means to collect intermittent condensate returns and supply water at a relatively constant volume, while limiting discharge to drain.
A surge/transfer system is an important component in a steam system when there is a high volume of condensate returns, or the returns come back in “slugs”. A surge tank will allow this condensate to be collected at varying rates, and transfer the condensate/make-up mix to the deaerator under steady state conditions.
Softeners
Water softener is a unit that is used to soften water, by removing the minerals that cause the water to be hard preventing scale build up on heat transfer surfaces while maintaining peak boiler efficiency. Removing hardness also reduces the need for expensive chemical treatment to control scale.
When water is hard, it can clog pipes and soap will dissolve in it less easily. Water softening can prevent these negative effects. Due to this build-up, pipes are blocked and the efficiency of hot boilers and tanks is reduced. This increases the cost of domestic water heating by about fifteen to twenty percent.
Water softening means expanding the life span of boilers and the life span of pipelines. A water softener is recommended whenever raw hardness exceeds 1 ppm.
Water softeners are available for boilers of all sizes, including multiple boiler applications, steam or hot water.
Chemical Feed System
A well-engineered chemical feed system is an integral part of an effective water treatment program. If a feed system is not designed properly, chemical control will not meet specifications, program results may be inadequate, and operating costs will probably be excessive.
A significant investment in a chemical feed system can often be justified when compared with the high cost of these control problems. When a chemical feed system is not properly engineered, chemical levels are often above or below program specifications. The use of a proper feed system can prevent this situation.
Automatic systems are available for single- or multiple-boiler installations.
Boiler Feed System
A boiler feedwater pump used to pump feedwater into a steam boiler. The water may be freshly supplied or returning condensate produced as a result of the condensation of the steam produced by the boiler. These pumps are normally high pressure units that take suction from a condensate return system and can be of the centrifugal pump type or positive displacement type.
Boiler feed systems help maintain peak efficiency and prolong the life of boilers where investment in a deaerator cannot be justified. Consisting of one or more feed pumps and a corrosion resistant receiver tank, the system automatically supplements condensate with makeup water to replace system losses. Pumps are available in centrifugal or regenerative turbine types and vertical or horizontal configurations to fit your application.
For your “non-standard” requirements, let BFS customize a system “tailor made” for your application. Customizing includes tanks of any size, material or configuration, electric controls with any level of sophistication and pumps of any style or manufacturer.
