A pulverized coal boiler is an industry or utility boiler which generates thermal energy by burning pulverized coal (also known as powdered coal Or Coal dust because it is as fine as powder For cosmetic makeup) which is blown into the focus.

The basic idea of ​​a firing system using pulverized fuel is to use the entire volume of Furnace for the combustion of solid fuels. The coal is ground to the size of a fine grain, mixed with air and burnt in the flue gas stream. Biomass and other materials may also be added to the mixture. Coal contains mineral matter converted to ash during combustion. The ash is removed as ash and fly ash. The bottom ash is removed from the bottom of the oven.

This type of boiler dominates the electric power industry, supplying steam to drive large turbines. Pulverized coal provides thermal energy that produces about 50% of the world’s power supply.

History edit ] / H2>

Before the developments leading to the use of pulverized coal, most boilers used Firing grid , where the fuel was mechanically distributed on a moving grid at the bottom of the firebox in the form of partially crushed gravel. Air for combustion was blown upward through the grid carrying the lighter ash and smaller particles of unburned coal with them, some of which would adhere to the sides of the combustion chamber. In 1918, Railway and Light Company of Milwaukee Electric , Later Wisconsin Electric, conducted tests in the use of pulverized coal at its Oneida Street Factory . These experiments helped Fred L. Dornbrook develop methods to control pulverized coal-spoiled ash residues with hot water jackets that reduced the surface temperature of the fireplace walls and made it possible to easily remove deposits of ashes. This plant became the first power plant in the United States to use pulverized fuel.

The Oneida Street Generating Station near Milwaukee City Hall was then decommissioned and renovated in 1987. It is now the site of the Milwaukee Theater.

How it works ]

The concept of burnt coal that has been sprayed into a fine powder stems from the belief that if the coal is fine enough it will burn almost as easily and efficiently as a gas. The rate of coal supply according to boiler demand and the amount of air available for drying and transporting pulverized coal are controlled by computers. Pieces of coal are crushed between balls or cylindrical rollers that move between two tracks or “races”. The raw coal is then introduced into the sprayer with air heated to about 650 ° F / 340 ° C of the boiler. As the coal is crushed by rolling action, the hot air dries it and blows the fine coal powder usable for use as fuel. The powdered coal of the sprayer is directly blown into a burner in the boiler. The burner mixes the powdered coal in the air suspension with additional preheated combustion air and the force out of a similar nozzle in action for the fuel being atomized by a fuel injector in modern cars. Under operating conditions, there is sufficient heat in the combustion zone to ignite all incoming fuel.

Ash Removal Edit ] Pulverized_coal-fired_boiler &

There are two methods of removing ashes from the bottom of the oven:

The fly ash is taken with
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Pulverized coal-fired power plants fall into three categories; coal plants subcritical based on pulverized coal (SubCPC) supercritical pulverized coal (SCPC) Ultra-supercritical plants and plants with pulverized coal (USCPC). The main difference between the three types of pulverized coal boilers are temperatures and operating pressures. Subcritical plants operate below the critical water point (647,096 K and 22,064 MPa). Supercritical and ultra-supercritical plants function above the critical point. As the pressures and temperatures increase, the operating efficiency is also high. Subcritical plants are about 37%, supercritics about 40% and ultra-supercritical in the range of 42-45%.

Steam Locomotives Edit ] title = Pulverized_coal-fired_boiler & action = edit & amp; >

Pulverized coal fired was used, to a limited extent, in Steam locomotives . For example, see Prussia G 12 .

Merchant Ships

In 1929, United States Shipping Board evaluated A sprayer The charcoal boiler on Mercer , a merchant ship of 9,500 tons. According to their report, Mercer with its pulverized coal boiler ran 95% efficiency of its best oil voyage. It was cheaper to operate and install than the ship’s boilers using oil as fuel. [1]

See also See also edit ] >

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