摘要:
A system and method are presented for recovering heat from flue gas produced by a recovery boiler in a pulp and paper mill, the recovery boiler having a flue stack. Flue gas is drawn from the flue stack and passed through a first and second condensing heat exchangers before exiting through a separate stack. The first heat exchanger is used to heat boiler feedwater whereas the second heat exchanger is used to produce process hot water for use in the pulp and paper mill. Steam previously used to heat the boiler feedwater and produce the process hot water can now be used to generate electricity that can be used for the pulp and paper mill operations or to export to the electrical power grid.
摘要:
In a method for processing ash, fly ash is separated from a product gas flow obtained from gasification of fuel, which fly ash is burned in fluidized bed combustion to reduce the carbon content of the ash. After this, the flue gases from the combustion are processed. In a first step, the ash is burned in fluidized bed combustion (fluidized bed reactor 1) at a temperature of not higher than 800° C. to reduce the carbon content, and in a second step, the flue gases a burned in an independent combustion process (combustion chamber 7), the combustion conditions reaching the temperature of at least 850° C.
摘要:
A method for treating ash produced by waste coal fluidized bed boilers in which hot ash fines and heated secondary air are introduced into the boiler as the coarse ash is cooled. An ash treatment system for cooperation with a fluidized bed boiler operating on waste fuel having a high ash content receives and classifies hot ash from the boiler, returns ash fines to the boiler, cools coarse ash fines for disposal and burns carbon associated with the ash received from the boiler.
摘要:
Flue dust precipitated from the compressed gas from a fluidized-bed combustion chamber is conveyed by flue gas to an air-lock system while simultaneously being cooled to above the water and acid dew point of the flue gas. As it enters the air-lock system, the dust is separated from the flue gas and, once it has left the air-lock system, the dust is conveyed by air while simultaneously being cooled to a final temperature at which it can be removed.
摘要:
A pneumatic conveying system for conveying particulate material includes a connection chamber for changing the direction of flow so as to bring about a pressure drop. An upstream tube and a downstream tube are connected, spaced from each other, to an end wall in the connection chamber. Between the tubes, the end wall is formed with a double-curved surface bulging inwards towards the connection chamber, said surface being suitably saddle-shaped.
摘要:
A method and apparatus is provided for reducing and measuring carbon content in fly ash. The invention employs microwave energy as the method of heating for inducing combustion of the carbon in a fly ash sample. Measurement of the carbon content can be accomplished in accordance with the present invention by measuring temperature differential of an excess energy absorber in the form of water before and after the fly ash is exposed to microwave radiation.