CN1252414C - Wet coal particle environmental protection circular fluidized bed mixing combustion technology - Google Patents

Abstract

The present invention relates to mixing combustion technology of a wet coal particle environmental protection circulating fluidized bed. Coal has two coal inlets; large coal particles enter a furnace from the bottom; coal powder less than 3mm without wet combustible wastes are loaded into the furnace from the middle in particle shape through a special wet coal particle forming machine; a circulating fluidized bed boiler is reformed according to technical requirements; after the circulating fluidized bed boiler is reformed, the unburned carbon in flue dust is reduced by 2% to 4%, the heat transfer performance is increased, the abrasion is reduced, the heat efficiency is increased by about 3% to 5% and can reach 90%. Because bottom combustion makes preparations for middle combustion, the quick entering state of combustion of the coal entering from the middle, and the thorough combustion of the bottom unburned parts in the middle are guaranteed; a small number of desulphurizing agents is added into coal entering from the middle, and a strong desulfuring zone is formed in a middle high-temperature zone to guarantee effective devulcanization. In addition, combustible waste liquid of wet wastes such as urban mixing mud, etc. can be added into the coal to manufacture wet coal particles. The combustible constituent in garbage is used, garbage objects obsessing cities are processed, and the comprehensive utilization of environmental protection is realized.

Description

Wet coal grain environment-friendly type recirculating fluidized bed mixed combusting technology

The technology summary

This patent is used for coal-burning boiler mode thermal source manufacturing enterprise, cogeneration of heat and power enterprise.This patent has improved boiler combustion efficiency, reduce SO 2 from fume, oxynitrides content and unburned carbon in flue dust, and the municipal sludge of incendivity some etc. has the industrial wastes of combustible, play the effect of handling the environmental protection discarded object, changed grey slag ingredient simultaneously, but production infant industry, agricultural products.

The background situation

CFBB is called as cleaning combustion boiler, and its combustion temperature in hearth is controlled between the 850-950 degree, and this temperature range has been decomposed many harmful components, therefore is called environment-protection boiler, also allows to be used for the city proper abroad.But the CFBB of traditional single fuel firing, all in the same area burning, fail to distinguish by varigrained burning situation from the 0-10 millimeter for fuel granularity, and small particle powder is blown out burner hearth fast, causes unburned carbon in flue dust higher; Temperature range concentrates on concentrated phase area and dilute-phase zone position, the unburned thing have part too early leave the high-temperature region, cause imperfect combustionly, not only reduced efficiency of combustion, and influenced the control of desulfurization and oxynitrides, cause the environmental index of environmental requirement to be difficult to reach.Domestic CFBB all is this state basically at present, and boiler thermal output is between 80%-87%.

Patented technology

Adopt wet coal grain mixed combusting technology, coal supply is divided into two coal feed points, one in the bottom, and one at the middle part.The big coal grain of 3-12mm is sent into burner hearth from the bottom, the following powder of 3mm is added water make the moulded coal (hygrometric state) of prescribed level, send into burner hearth from the middle part with the on-fluent graininess through task equipment.According to the present technique requirement, all to make corresponding transformation to burner hearth, heating surface, abrasionproof, air distribution.Improved CFBB; Unburned carbon in flue dust reduces 2%--4%; Exchange capability of heat improves; Wearing and tearing reduce; The thermal efficiency can improve about 3%-5%, can reach 90%.

Because the small particle powder water is reunited it, has prolonged the burning time at burner hearth greatly, has increased the saturating property of combustion of powder; Owing to be divided into two sections coal supplies, coal feeding hole space-number rice has increased the primary zone area greatly again, and the air distribution amount more evenly is fit to, and it is more complete to burn, and high-temperature surface elongates, and exchange capability of heat greatly improves; The low combustion value fuel of bulky grain is adopted in the bottom, and available gangue etc. form the insulation siege, because understoke quantity reduces, the relative wear amount reduces; Base burning is that the middle part burning is prepared, and advance coal in the middle part of having guaranteed and enter fired state fast, and unburned part in bottom is thoroughly burnt at the middle part; Advance to have added little excessive desulfurizing agent in the coal at the middle part, formed a strong desulfurization zone in the high-temperature region, middle part, guaranteed effective desulfurization.

Owing to adopted wet combustion, the discarded object of hygrometric state can be contained the combustible waste liquid as municipal sludge, paper mill waste liquid, cotton mill waste liquid etc. in addition, call in the coal, make wet coal grain, promptly utilized the combustible constituent in the rubbish, handle the rubbish thing in puzzlement city again, realized the comprehensive utilization of environmental protection.

Embodiment

As shown in drawings

1, intrinsic burner hearth is increased (except the old stove), a coal inlet hole is opened at the middle part, and special-purpose wet coal grain make-up machine (2), adjustable wind-force coal conveyor (3) are installed.

2, at coal-hole (9) screening installation--screening machine (11) is installed, the following coal grain of 3mm (12) is sifted out, the above coal grain of 3mm (6) enters coal breaker (5), former coal bunker (4), sends into burner hearth (1) by original coal communication system.

3, the following coal grain of 3mm (12) is sent into the machine of being mixed (10), raw coal, lime stone, municipal sludge, combustible waste liquid etc. are mixed, send into wet coal grain make-up machine (2) through conveyer (8) by prescription.Send into burner hearth (1) by wind-force coal conveyor (3) again.

4, adjust operating mode, one time wind reduces, and gets final product than basic fluidisation is more bigger, moves on the zone of positive pressure appropriateness, causes the peroxidating burning.Adjust wet coal grain air-supply air quantity and reach smooth combustion.

This patent is simple and practical, small investment, operating cost is low, but and the processing section municipal refuse, improve energy utilization rate.With cool water mixture burning mode ratio, system oarage investment significantly reduces (be system oarage 1/10); Operating cost is low; Moisture is more than 35% in the water-coal-slurry simultaneously, and the latent heat of vaporization that enters the burner hearth generation will consume a large amount of heats, reduce boiler thermal output 2%--3%; Do not have coal oar sedimentation problem, store, carry all more simple and convenient.Wet coal grain mixed combusting technology is the new raising to CFBB.

Claims (3)

1, wet coal grain environment-friendly type recirculating fluidized bed mixed combusting technology; coal supply is divided into two coal feed points; one in the bottom; one at the middle part; the big coal grain of 3-12mm is sent into burner hearth from the bottom; the following powder of 3mm adds water through being mixed, stirring, and uses wet coal grain shaping mechanism to become the hygrometric state moulded coal of prescribed level, sends into the recirculating fluidized bed burner hearth from the middle part with the on-fluent graininess.

2, wet coal grain environment-friendly type recirculating fluidized bed mixed combusting technology according to claim 1 is characterized in that and hygrometric state combustible waste material such as municipal sludge, paper plant, textile mills, sugar refinery waste liquid etc. can be called in the wet coal particle, reaches the comprehensive utilization of environmental protection and energy saving.

3, wet coal grain environment-friendly type recirculating fluidized bed mixed combusting technology according to claim 1 is characterized in that the following coal dust of 3mm end is added flammable hygrometric state discarded object, is processed into hygrometric state on-fluent particle through wet coal grain make-up machine.