BOILER
SYSTEMS
Boilers in their many shapes and sizes produce steam, which in turn is used for a variety of operations, including electrical power generation via turbines, chemical processing, and numerous heating applications. The steam produced in the boilers must be of acceptable purity, as dictated by the operation for which it is intended. The efficiency of the boiler depends upon the manner in which the boiler support systems are operated.
The three support system are: pretreatment, feed water, and condensate.
The pretreatment as the name implies, water is first treated before it reaches the boiler. The general purpose of the pretreatment is to remove both suspended and soluble solids that, if not removed, could lead to boiler deposits and poor steam purity. The pretreatment system usually consists of one or more of the following operations:
Hot or cold lime softening
Filtration
Ion exchange softening
Dealkalization
Demineralization
Reserve osmosis
Feed water is the final stream of water that enters the boiler. It is composed of water from the pretreatment system plus any water returned from the condensate system.
Condensate is a valuable component of feed water. It is of high purity and contains a significant amount of heat. The more condensate that can be returned, the less fuel that needs to be consumed, and generally the less makeup water is that required from pretreatment. Just as makeup water from pretreatment must meet certain criteria, so must condensate. It is imperative that each support system is at its best efficiently. Otherwise, maintenance costs and process inefficiency will increase, and ultimately, a plant or process shutdown could occur.
Successful boiler system operation requires a total system approach to
Prepare makeup water to meet system requirements before it goes to the boiler
Provide pre boiler, boiler, and post-boiler corrosion protection
Maintain clean internal boiler surfaces
Maximize system availability
Ensure reliable steam production acceptable for the intended use
Extend boiler system life
Protect production processes and equipment
Maximize the value of condensate return
Optimize energy efficiency
Assure safety and regulatory compliance