CN201218498Y - Flying ash circulating combustion system for circulating fluidized bed boiler - Google Patents

Abstract

The utility model relates to a circulating fluidized bed boiler, in particular to a flying ash circulating burning system of the circulating fluidized bed boiler. A bypass ash taking bucket is arranged below an ash collecting bucket of an electrical dust remover; the bypass ash taking bucket is connected with the first input port of a gas-solid mixer through a transfer piping, and the second input port of the gas-solid mixer is connected with a Roots blower; and the output port of the gas-solid mixer is connected to the hearth of the circulating fluidized bed boiler through a transfer piping. The utility model mainly solves the technical problem existing in the practical operation of a boiler in the prior art that part of limestone craps and calcium oxide does not react completely and break away from a combustion zone of the boiler to fly together with the flying ash, adopts a method of pneumatic transport to cause the limestone craps and the calcium oxide to return to the hearth of the boiler to be burned again, and improves the desulfurizing efficiency of flue gas and the combustion efficiency of the boiler.

Description

CFBB flying dust circulating combustion system

Technical field

The utility model relates to CFBB, particularly a kind of CFBB flying dust circulating combustion system.

Background technology

CFBB mixes the race (Main Ingredients and Appearance calcium carbonate) of 3%-5% in fire coal, in burner hearth in the process of high-temp combustion, calcium carbonate decomposes and carries out chemical reaction with sulphur content in the fire coal, generates calcium sulfate, reaches the purpose of boiler flue gas desulfurization.In the boiler actual motion, part race, calcium oxide do not have complete reaction, promptly break away from the boiler combustion district with flying dust, enter electric cleaner by flue.Be deposited in the flying dust of the first electric field ash bucket carbon content 5-10%, calcium oxide content 8-10%, the utilization rate of race is lower, Small and Medium Circulating Fluidized Bed Boiler particularly, the desulfuration efficiency that improves flue gas need drop into more race, certainly will increase the boiler operatiopn cost.

The utility model content

The purpose of this utility model is to provide a kind of CFBB flying dust circulating combustion system, mainly solve in the boiler actual motion of prior art, part race, calcium oxide do not have complete reaction, promptly break away from the technical problem of boiler combustion district with flying dust, the method that adopts strength to carry, turn back to burning once more in the boiler furnace, improve the smoke desulfurization efficiency and the efficiency of combustion of boiler.

For addressing the above problem, the utility model is achieved in that

A kind of CFBB flying dust circulating combustion system, it is characterized in that: below the electric cleaner flue-dust retainer, have bypass and get ash bucket, ash bucket connects the gas-solid blender by conveyance conduit first input end mouth is got in bypass, second input port of gas-solid blender is connected with roots blower, and the output port of gas-solid blender is connected to boiler hearth of circulating fluidized bed by conveyance conduit.

Described CFBB flying dust circulating combustion system is characterized in that: this bypass is got on the conveyance conduit between the first input end mouth of ash bucket and gas-solid blender has the VFC rotary valve.

Described CFBB flying dust circulating combustion system, it is characterized in that: this gas-solid blender is the threeway that is the T font.

By technique scheme, the utlity model has following advantage:

The utility model is under the extension tube attached below the electric cleaner first electric field ash bucket of CFBB, adopt a cover Pneumatic conveyer, flying dust is drawn from electric cleaner first electric field, be transported in the boiler furnace by pipeline, make the sulfur dioxide of calcium oxide in burner hearth and coal in the flying dust that chemical reaction take place once more, improve the desulfuration efficiency of boiler, the remaining char in the flying dust is burning once more in burner hearth, makes the also corresponding raising of efficiency of combustion of boiler.In addition, because flying dust is once more behind the circulating combustion, the utilization rate of race improves, and has reduced the use amount of boiler flue gas desulfurization race.Calcium oxide content reduces in the flying dust, and low calcium flying dust can be used as cement and mixes material, and the flying dust value is improved.

Description of drawings

Fig. 1 is a structural representation of the present utility model.

Among the figure:

The 1-roots blower;

2-electric cleaner flue-dust retainer;

Ash bucket is got in the 3-bypass;

4-VFC rotary valve;

5-gas-solid blender;

51-first input end mouth;

52-second input port;

The 53-output port;

The 7-boiler hearth of circulating fluidized bed.

The specific embodiment

See also Fig. 1, the utility model discloses a kind of CFBB flying dust circulating combustion system.As shown in the figure: below electric cleaner flue-dust retainer 2, have bypass and get ash bucket 3, ash bucket 3 connects gas-solid blender 5 by conveyance conduit first input end mouth 51 is got in bypass, second input port 52 of gas-solid blender 5 is connected with roots blower 1, and the output port 53 of gas-solid blender 5 is connected to boiler hearth of circulating fluidized bed 7 by conveyance conduit.This bypass is got on the conveyance conduit between the first input end mouth 51 of ash bucket 3 and gas-solid blender 5 has VFC rotary valve 4, the effect of this VFC rotary valve 4 is the variations according to boiler operatiopn operating mode, boiler flue gas desulfurization efficient, regulates the flying dust internal circulating load.This gas-solid blender 5 is the threeways that are the T font.

After CFBB of the present utility model adopted flying dust circulating combustion technology, the utilization rate of race improved, and use amount reduces 50%, and utilizations of burning once more of the carbon residue in the flying dust saved fire coal more than 1.5%.With 35 tons of/hour CFBBs operation was example in 7000 hours/year, reduce race and consume 470 tons/year, energy-conservation 470 tons of standard coals, press 280 yuan/ton of races, 875 yuan of/ton calculating of standard coal, annual 540000 yuan of the operating costs that reduce, 100,000 yuan of the Pneumatic conveyer costs that flying dust circulating combustion technology adopts come into operation and can recoup the investment in three months.

Being preferred embodiment of the present utility model only in sum, is not to be used for limiting practical range of the present utility model.Be that all equivalences of doing according to the content of the utility model claim change and modification, all should be technology category of the present utility model.

Claims (3)

1, a kind of CFBB flying dust circulating combustion system, it is characterized in that: have bypass in electric cleaner flue-dust retainer (2) below and get ash bucket (3), ash bucket (3) connects gas-solid blender (5) by conveyance conduit first input end mouth (51) is got in bypass, second input port (52) of gas-solid blender (5) is connected with roots blower (1), and the output port (53) of gas-solid blender (5) is connected to boiler hearth of circulating fluidized bed (7) by conveyance conduit.

2, CFBB flying dust circulating combustion according to claim 1 system is characterized in that: this bypass is got on the conveyance conduit between the first input end mouth (51) of ash bucket (3) and gas-solid blender (5) has VFC rotary valve (4).

3, CFBB flying dust circulating combustion according to claim 1 and 2 system, it is characterized in that: this gas-solid blender (5) is the threeway that is the T font.

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