What is convection in boiler?

Convection is the process of transferring heat by movement energy through a material. When any fluid in a steam boiler is heated, its density is decreases and the fluid become lighter. Then the heavier or cooler fluid will flow and replace the heated portion of the fluid. In turn the cooler portion becomes heated.

What is pass in boiler?

Each set of tubes that hot combustion flue gas travels through before making a turn within the boiler, is considered a “pass.” A 3-pass firetube boiler design consists of three sets of horizontal tubes, with the stack outlet located on the rear of the boiler.

How do I reduce boiler fouling?

Increase Heat Rate, Lower Furnace Gas Exit Temperatures (FGET) IGS ceramic coatings can help increase heat absorption into boiler tubes by reducing the amount of slag or fouling on the OD surface of the tube, and by eliminating the formation of corrosion scales on the tubes surface.

What is a boiler feedwater circulation system?

The piping system carrying the water to the economizer inlet header is called the feedwater piping system. The steam drum is 6.5 ft in diameter and collects and distributes the water/steam as it continuously circulates throughout the boiler.

Where are the convection pass enclosures located on a boiler?

The two pass type of utility boilers has convection pass enclosures that are located adjacent the furnace enclosure. The pendant convection pass enclosure connects the furnace enclosure to the horizontal convection pass enclosure.

How is convection involved in heat transfer in a boiler?

Involved in the heat transfer in a boiler. No convection does not occur in the core. There are two types of convection heat transfer one being free convection. For example in the sun the convection occurs only after the radiation zone. There are two ways to calculate heat transfer due to radiation in boiler.

What does the number of boiler passes mean?

The number of boiler passes simply represents the number of times the hot combustion gas travels across the boiler (heat exchanger). A boiler with two passes provides two opportunities for the hot gasses to exchange heat to the water in the boiler. A 4-pass unit provides four opportunities for heat transfer.

Where does convection take place in a furnace?

The part of a furnace between the radiant section and the stack. The area is filled with tubes or pipes which carry process steam and which absorb heat via convection heat transfer from the hot gases passing through the area on their way out of the stack.