RU78903U1 - SOLID FUEL PREPARATION SYSTEM FOR COMBUSTION - Google Patents

Abstract

A system for preparing solid fuel for burning, including a raw fuel hopper sequentially located in the technological chain, a raw fuel feeder, a hot air path, a mill, a separator, a dust return dust pipe, a cyclone, a dust hopper, a mill fan, a dust feeder, a mixture mixture, burners, a boiler , an air heater, characterized in that in front of the burners of the boiler, an activator additive hopper, an activator additive feeder, an active mixture pipeline and a mixer are additionally installed.

Description

The invention relates to the field of preparation of solid fuel for combustion at thermal power plants.

A known system for preparing and burning solid fuel in a dust preparation system. A system for preparing and burning solid fuels, including sequentially arranged means for receiving and dosed feed of raw coal into devices for drying and grinding it in a stream of a gaseous drying agent pumped through the latter, a device for separating aerosol mixtures obtained after grinding coal into spent, slightly dusty drying agent and coal dust, coal dust storage - industrial bin with coal dust feeders, a mill fan for exhausting spent slack a flax drying agent, a furnace, for example, a steam generator of a boiler plant, equipped with main fuel burners located at different levels along its height, discharge burners and nozzles for supplying clean (secondary) air separately from the burners, dust conduits for supplying aerated highly concentrated air-fuel mixture to the main fuel burners with primary air, each equipped with a separate mixer, into which coal dust is supplied with a separate dust flow from the coal dust feeder of the industrial bin and of primary air water, dust supply lines to the exhaust burners of the part of the spent drying agent pre-enriched with the main fuel, air and gas pipelines for supplying respectively hot air from the air heater and flue gases from the furnace as the main drying agent or its component and for supplying these media to other system nodes. The dust pipelines of the supply to the exhaust burners of the flow of the spent drying agent, previously enriched in basic fuel, are each equipped

a mixer into which coal dust is supplied (with an adjustable flow rate) from the coal dust feeder of the industrial bin with a separate dust heat, and the supply of the spent slightly dusty drying agent is made to these mixers from the outlet of the mill fan (directly or through the box of spent drying agent) with the addition of flow, if necessary, of flue gases (RU 2202739 C2, RF, IPC 7 F23K 1/00).

The system has the disadvantage that when preparing fuel for burning, it cannot improve its physicochemical characteristics, as a result of which the process of burning fuel dust in the furnace of a steam boiler (steam generator) proceeds due to combustible elements of fuel dust or in its mixture with highly reactive fuels (natural gas or fuel oil).

Known individual closed dust preparation system with an intermediate hopper. The system includes: a raw fuel bunker, a raw fuel feeder, a hot air path (box), a mill, a separator, a dust return pipe (heat), a cyclone, a dust bunker, a mill fan, a dust feeder, an air mixture, burners, a boiler, an air heater . A dust preparation system with an intermediate hopper makes it possible to grind crude fuel, separate large fractions from small fractions, mix fuel dust with hot air and route it through pipelines to the boiler burners (Thermal and Nuclear Power Plants: Reference Book / Ed. By V.A. Grigoriev and B .M. Zorina. - 2nd ed., Revised. - M.: Energoatomizdat, 1989, S. 28-39.).

The disadvantages of the prototype include the lack of the ability to improve the physico-chemical characteristics of the raw fuel crushed in the mill in front of the boiler burners, which is necessary to improve the combustion process in its combustion chamber.

The objective of this solution is to increase the physicochemical characteristics of crude solid fuel, including low-reactivity, and to improve the process of its ignition in the boiler furnace.

The technical problem is solved as follows, a system for preparing solid fuel for burning, including a raw fuel hopper sequentially located in the technological chain, a raw fuel feeder, a hot air path, a mill, a separator, a dust return dust pipe, a cyclone, a dust hopper, a mill fan, a dust feeder , a mixture pipeline, burners, a boiler, an air heater, and in front of the burners of the boiler an additional activator-hopper, an activator-additive feeder, and an active mixtures and mixer, which contributes to the active mixing of the additive with aerosol (mixture of crushed fuel and air) and to improve the process of ignition and combustion of fuel in the boiler furnace.

Figure 1 shows a system for preparing solid fuel for combustion.

The system for preparing solid fuel for combustion consists of: 1 - a raw fuel bin; 2 - raw fuel feeder; 3 - mills; 4 - dust return pipe; 5 - separator; 6 - cyclone; 7 - dust bunker; 8 - mill fan; 9 - dust feeder; 10 - hopper additives activator; 11 - feeder additives activator; 12 - mixer; 13 burners; 14 - boiler; 15 - air heater; 16 - hot air tract; 17 - pipeline mixtures; 18 - pipeline active mixture.

The system for preparing solid fuel for combustion works as follows. Crude solid fuel is fed into the crude fuel bin 1, from where it passes to the mill 3 through the raw fuel feeder 2, which controls its flow rate. Hot air is supplied from the duct 3 to the mill 3 from the duct 16 for drying and transporting the fuel to cyclone 6. In the mill 3 the fuel is ground to the required grinding fineness, which is then sent to the separator 5, where

separation of large fractions of fuel from small ones. Coarse fuel through the dust pipe 4 is returned to the mill 3 for re-grinding. Fine fuel with hot air (drying agent) is sent to cyclone 6, where the drying agent and fine fuel are separated, while the drying agent is sent to the burners of boiler 14 using a mill fan 8. Fine fuel is poured into the dust bin 7, from where, through the dust feeder 9, it is sent to the pipe 17, where a fuel mixture (aerosmix) of hot air is created, heated in the air heater 15, with finely ground fuel, which is sent to the burners 13 of the boiler 14. To improve Due to the formation of the aerosol mixture due to the formation of its physicochemical characteristics, an activator 10 bin is built into the solid fuel preparation system, from where, through the feeder of the activator additive 11, the activator additive is sent to the mixer 12, in which the additive is actively mixed by ejection suction -activator with aerosol. After which the newly formed active mixture through the pipe 18 is sent to the burners 13 of the boiler 14.

The proposed technical solution allows you to change the physico-chemical characteristics of solid fuel (coal dust), including its reactivity, and thereby improve the ignition and combustion of coal dust in the boiler furnace.

The invention can be implemented on the basis of existing systems for the pulverization of thermal power plants.

Claims (1)

A system for preparing solid fuel for burning, including a raw fuel hopper sequentially located in the technological chain, a raw fuel feeder, a hot air path, a mill, a separator, a dust return dust pipe, a cyclone, a dust hopper, a mill fan, a dust feeder, a mixture mixture, burners, a boiler , an air heater, characterized in that in front of the burners of the boiler, an activator additive hopper, an activator additive feeder, an active mixture pipeline and a mixer are additionally installed.