CN1268389A

CN1268389A - Coal-fired flue-gas dust-removing and desulfurization process

Info

Publication number: CN1268389A
Application number: CN 99115305
Authority: CN
Inventors: 陈汉东; 王继微; 陈希宗; 张海良; 张生好; 陈建军; 何正华
Original assignee: Inst Of Environmental Protection Engineerings Nanfang Academy Of High & New Te
Current assignee: Inst Of Environmental Protection Engineerings Nanfang Academy Of High & New Te
Priority date: 1999-03-31
Filing date: 1999-03-31
Publication date: 2000-10-04

Abstract

A method for removing dust and sulfur in coal-burning flue gas is disclosed, and it uses water and lime milk liquid as dust collector and desulfurizing agent. In the dust collector tower, the dust removal rate is higher than 90% and sulfur removal rate is about 15%; and at the sulfur renoval tower, the sulfur removal rate is higher than 80%. After passing through dust collector tower and sulfur removal tower, the sulfur removal rate of final flue gas is about 95% and the dust removal rate of final flue gas is greater than 99%.

Description

Coal-fired flue-gas dust-removing and desulfurization process

The present invention relates to a kind of process of from coal-fired flue-gas, removing sulfur dioxide.

At present, large-scale coal-fired station, be rich in sulfur dioxide flue gas to airborne release, it is one of reason that causes global serious acid rain day by day, in order to reduce the content of coal-fired station's discharging sulfur dioxide in flue gas, to reach environmental requirement, a kind of rotating spraying dry flue gas desulphurization technology is adopted in these coal-fired thermal power generation, this is the method for the sulfur dioxide in a kind of direct smoke treatment, be that quick lime is mixed with certain density calcium hydroxide lime slurry, centrifugal atomizer with rotation at a high speed is 70 microns droplets that the left and right sides is superfine with the lime white atomizing, in the absorption tower, contact, strong heat exchange and chemical reaction take place, generate calcium sulfite dry state lime-ash and discharge with sulfur in smoke, mainly there is following shortcoming in this technology: 1. the utilization ratio of lime is low, and use amount is big; 2. the easy fouling of spray nozzle is stopped up, and is unfavorable for continued operation, and maintenance cost is too high; 3. dry state residue treatment difficulty, the equipment complexity; 4. moisture content raise significantly after flue gas was handled, to the equipment for after-treatment seriously corroded.

It is simple to the purpose of this invention is to provide a kind of equipment, and technological process is short, the dust-removal and desulfurizing rate coal-fired flue-gas dust-removing and desulfurization process of small investment.

2, technical scheme of the present invention is: coal-fired flue-gas dust-removing and desulfurization process, and it is:

1) with after the stirring in the digestion machine of lime and water adding additive, puts into the milk of lime pond

Stand-by;

2) the coal gas flue gas is introduced the gas wash tower bottom through pipeline from combustion furnace, use milk of lime

Pump and clarified water pump get off lime slurry and clear water from gas wash tower top atomized spray

Tail washings floss hole at the bottom of the dedusting Tata is discharged, and enters sedimentation basin, filters, with coal ash

Slag is together handled;

3) in the gas wash tower dedusting, the coal-fired flue-gas of partial desulfurization is drawn from the dedusting cat head, through pipe

The desulfurizing tower bottom is introduced in the road, extracts lime liquor with milk of lime pump out from the milk of lime pond

From desulfurizing tower desulfurization section top atomized spray;

4) coal-fired flue-gas of drawing at the desulfurizing tower desulfurization section, the foam removal section place through the desulfurizing tower top

Reason, remove the mist in the coal-fired flue-gas after, draw from the desulfurizing tower top, again through ventilating

Power traction is gone into the chimney emptying.

The present invention is because of adopting clear water, milk of lime two-stage dust-removal and desulfurizing, the technical indicator that reaches:

1. coal sulfur-bearing＜5%, desulfurization degree 85-95%;

Coal sulfur-bearing＜2.5%, desulfurization degree 90-95%;

2. dust removal efficiency＞99%;

3. lingemann blackness＜1 grade.

The present invention has following advantage:

1. equipment is simple, and technological process is short, small investment

2. the easy fouling of the equipment in the past that solved is stopped up, easily the problem of corrosion;

3. easily the waste liquid after the smoke treatment is collected, handled, production has high added value

Fine chemical product, eliminate the secondary pollution of waste liquid;

4. the utilization rate of lime improves greatly, has saved operating cost.

Below in conjunction with accompanying drawing the present invention is described in further detail:

Fig. 1 is a process flow diagram of the present invention.

As shown in Figure 1: lime and water doping generate lime slurry after the digestion machine is handled, enter in the milk of lime pond stand-by; Coal-fired flue-gas is introduced the gas wash tower bottom by pipeline, with milk of lime pump 1 and clarified water pump 2 respectively from the milk of lime pond and in the clear water reserviors, extract lime slurry and clear water to the gas wash tower top, atomized spray is got off, in gas wash tower, to coal-fired flue-gas mainly based on dedusting, efficiency of dust collection is more than 90%, desulfuration efficiency is more than 15%, through the gas wash tower dedusting, the coal-fired flue-gas of partial desulfurization is drawn through pipeline introducing desulfurizing tower bottom from the gas wash tower top, extracts lime slurry out from desulfurizing tower desulfurization section top atomized spray from the milk of lime pond with milk of lime pump 3, coal-fired flue-gas is fully contacted with lime slurry, at this section desulfuration efficiency more than 80%; Can produce certain mist at desulfurization section because coal-fired flue-gas contacts with lime slurry, the coal-fired flue-gas after the desulfurization section desulfurization enters the foam removal section in the desulfurizing tower, carries out foam removal and handles, and removes the mist in the coal-fired flue-gas, and is last.Coal-fired flue-gas is drawn from the desulfurizing tower top, introduces the chimney emptying through ventilation blower, and the waste liquid in the desulfurizing tower bottom is introduced in the reactor through pipeline, separates, and produces byproduct, avoids the secondary pollution of waste liquid.

Claims

1, a kind of coal-fired flue-gas dust-removing and desulfurization process is characterized in that:

1) lime and water are added after additive stirs in the digestion machine, it is stand-by to put into the milk of lime pond;

2) the coal gas flue gas is introduced the gas wash tower bottom through pipeline from combustion furnace, with milk of lime pump and clarified water pump lime slurry and clear water are got off from gas wash tower top atomized spray, tail washings floss hole at the bottom of the dedusting Tata is discharged, and enters sedimentation basin, filter, together handle with the coal ash slag;

3) at the coal-fired flue-gas of gas wash tower dedusting, partial desulfurization, draw,, introduce the desulfurizing tower bottom, from the milk of lime pond, extract lime slurry out from desulfurizing tower desulfurization section top atomized spray with milk of lime pump through pipeline from the dedusting cat head;

4) draw coal-fired flue-gas at the desulfurizing tower desulfurization section, after the foam removal section at desulfurizing tower top is handled, removed the mist in the coal-fired flue-gas, draw, introduce the chimney emptying through ventilation blower again from the desulfurizing tower top.