Boilers By Ryan Majkut

Transcript Boilers By Ryan Majkut

Boilers

By Ryan Majkut

Objective:

to discuss different types of boilers and explain how they work

What is a Boiler?

• A water containing vessel which transfers heat from a fuel source (oil, gas, coal) into steam • This steam is piped to a point where it can be used to run production equipment, to sterilize, provide heat, to steam-clean, etc • Boilers are commonly used to heat larger office buildings • They work by sending hot water through pipes around the building that heat up the air around them and cause the room to get warmer

Fire-tube Boiler

• • A

fire-tube boiler

was more common in the 1800s. It consists of a tank of water perforated with pipes. The hot gases from a coal or wood fire run through the pipes to heat the water in the tank, as shown here: The whole tank is under pressure, so if the tank bursts it creates a major explosion

Water-tube Boiler

• More common today are

water-tube boilers

, in which water runs through a rack of tubes that are positioned in the hot gases from the fire

Boiler Systems

• •

Closed System

- The energy given up by the steam is sufficient to convert it back into the form of water. When 100% of the steam produced is returned to be reused, the system is called a closed system.

Open System

- Since some processes can contaminate the steam, it is not always desirable to feed the condensate back into the boiler. A system that does not return the condensate is called an open system.

A More Complex Water-tube Boiler

Condensing Boiler

• • uses a secondary heat exchanger or condensing coil to recover heat from the hot flue gases The temperature of this flue gas will be near to that of flame.

Feed Water Contamination

• The boiler receives the feed water, which consists of recovered condensed water (

return water

) and fresh water (make-up water) • The steam, which escapes from the boiler, frequently contains liquid droplets and gases • The water remaining in liquid form at the bottom of the boiler picks up all the foreign matter from the water that was converted to steam • These impurities lead to poor heat transfer and reduction in the efficiency of the boiler • The impurities must be

blown down

by the discharge of some of the water from the boiler to the drains

More Complex Systems

• • • • • Boilers may contain additional components such as: Economizers to increase the boiler efficiency Superheaters to heat the steam above the saturation temperature Process heaters and steam turbine systems to power a variety of steam Feedwater heaters to remove dissolved gases, such as oxygen

References

• • • • •

http://www.alken murray.com/Boilerworks.html

home.btconnect.com/.../ condensing_boiler.htm

http://www.business wiz.com/products/boilers.html

http://www.abma.com/pack_ft_ boilers.php