CN100451524C

CN100451524C - Method for converting to hot air from flue gas in baking furnace

Info

Publication number: CN100451524C
Application number: CNB200710055854XA
Authority: CN
Inventors: 张清波; 汪丹; 鲁玉春; 谷志君
Original assignee: CHINA NATIONAL GOLD Corp TECHNOLOGY CENTER
Current assignee: Changchun Gold Research Institute
Priority date: 2007-07-06
Filing date: 2007-07-06
Publication date: 2009-01-14
Anticipated expiration: 2027-07-06
Also published as: CN101093150A

Abstract

This invention relates to a method for converting smoke of calcining furnaces into hot air including: leading smoke into a heat exchanger and feeding cold air into it for heat exchange to reduce the temperature of the smoke to 350-400deg.C from 600-750deg.C and rise the cold air from 20deg.C under natural condition to 300-400deg.C, which is advantaged that a gas- heat exchanger is used to convert waste heat of baked smoke to hot air for reusing so as to fully utilize the waste heat resource and save cost of production.

Description

The method of converting to hot air from flue gas in baking furnace

Technical field

The present invention relates to a kind of method of UTILIZATION OF VESIDUAL HEAT IN, particularly a kind of method of converting to hot air from flue gas in baking furnace.

Background technology

As everyone knows, the hot flue gas that produces in the roasting process, owing in the subsequent technique flue-gas temperature is had certain requirement, so the processing of usually hot flue gas being lowered the temperature is satisfied subsequent technique and is reclaimed the improvement requirement; But, the hot flue gas that different roasting techniques produces, because smoke property difference, it is also different to reclaim the technology of administering, and for example high arsenic flue gas should satisfy the recovery of dust, satisfy the recovery of arsenic again, in order to prevent the formation of glass arsenic, sharply cooling when reclaiming arsenic is so the cooling type of cooling can be obviously different;

Generally, it is following several to take the cooling way roughly to have to baking flue gas: the one, and water-cooling wall and hot flue gas heat exchange obtain hot water, the method that hot water utilizes again; The 2nd, steam boiler and hot flue gas heat exchange obtain steam, utilize the method for steam-electric power; The 3rd, the method for utilizing plate type heat exchanger and surrounding air heat exchange to lower the temperature; The 4th, utilize the method for shower in the cooling of the outside directly spray of pipeline cold water; In the said method, preceding two kinds of commercial Application are more universal, also both economical, but, in more remote economically less developed region, because the hot water that reclaims can't utilize again or utilize nowhere, thermal water utilization is a cover system engineering in addition, need a large amount of investments, so, adopt the enterprise of spray cooling still to exist, like this, just wasted a large amount of residual heat resources, be badly in need of being improved.

Summary of the invention

The object of the present invention is to provide a kind of method of converting to hot air from flue gas in baking furnace, the hot-air of acquisition uses as the hot air source recirculation of roaster, has solved the problem that residual heat resources can not effectively be utilized, and then has saved the energy, reduces production costs.

Technical scheme of the present invention is: the hot flue gas converting to hot air of roaster, can well solve the problem that a large amount of waste heats are wasted, raw ore fluidized bed roasting engineering particularly, because roasting material thermal unbalance, need the external energy concurrent heating, like this, just hot flue gas converting to hot air can be supplied with roaster as the hot air source of fluidizing reactor uses, and then reduce coal-fired additional amount, so,, saved a large amount of energy additionally not increasing under the situation of investment, reduce production cost, improved the business economic benefit.

Concrete steps of the present invention are:

Step 1: flue gas is introduced heat exchanger

The flue-gas temperature that roaster produces is higher, and generally at 600 ℃～750 ℃, heat content is very big, owing to contain certain dust in the flue gas, so, require heat exchanger must possess the deashing function;

Flue gas is introduced by the heat exchanger bottom under the high temperature draught fan effect, and the dust that gravity settling chamber obtains returns roaster by the overflow spiral;

Step 2: air infeeds heat exchanger

The air of supplying with roaster at first feeds heat exchanger and carries out heat exchange, and air feeds from heat exchanger top, forms three stage countercurrent heat exchange forms with flue gas and carries out heat exchange;

Step 3: heat exchange

Flue gas feeds bottom heat exchanger, discharge on top, be covered with the air tubulation in the exhaust gases passes, air is fed by heat exchanger top tubulation, from top to bottom through after the heat exchange of three grades of tubulation bundles, 600 ℃～750 ℃ flue-gas temperature drops to 350 ℃～400 ℃, and air themperature is elevated to 300 ℃～400 ℃ by about 20 ℃ under the natural conditions.

The invention has the advantages that: utilize heat exchanger that baking flue gas waste heat converting to hot air is utilized again, made full use of the baking flue gas residual heat resources, reduce production costs, increase the business economic benefit; Reduce flue-gas temperature, satisfied follow-up flue gas managing technique needs, practical.

Description of drawings:

Fig. 1 is a process equipment schematic diagram of the present invention.

The specific embodiment:

Embodiment 1:

As shown in Figure 1, concrete steps of the present invention are as follows:

Step 1: flue gas is introduced heat exchanger

Flue gas 1 temperature that roaster produces is 680 ℃, exhaust gas volumn 30000m ³/ h under the high temperature draught fan effect, is introduced this flue gas 1 by the bottom of heat exchanger 2, the dust that contains in the flue gas is through gravity settling chamber and return roaster by overflow spiral organ 3;

Step 2: air infeeds heat exchanger

Air 4 temperature of supplying with heat exchanger are 20 ℃, and amount of supplied air is 28000m ³/ h, this air 4 feeds from heat exchanger top, forms three stage countercurrent heat exchange forms with flue gas and carries out heat exchange;

Step 3: heat exchange

Flue gas 1 by heat exchanger 2 bottoms feed, top discharges, be covered with air tubulation 7 in the exhaust gases passes, air 4 is fed by heat exchanger top tubulation 7, from top to bottom through after three grades of tubulation 7 heat exchanges, flue-gas temperature 5 is reduced to 380 ℃, air 4 temperature are elevated to 400 ℃, and the flue gas 6 after the cooling is discharged by the top of heat exchanger 2.

Present embodiment roaster coal supply amount 4.5% is equivalent to coal supply amount 1.125t/h, saves coal consumption and amounts to 4 yuan/ton of RMB, 800,000 yuan of year saving production costs.

Embodiment 2:

As shown in Figure 1, concrete steps of the present invention are as follows:

Step 1: flue gas is introduced heat exchanger

Flue gas 1 temperature that roaster produces is 700 ℃, exhaust gas volumn 32000m ³/ h under the high temperature draught fan effect, is introduced this flue gas 1 by the bottom of heat exchanger 2, the dust that contains in the flue gas is through gravity settling chamber and return roaster by overflow spiral organ 3;

Step 2: air infeeds heat exchanger

Air 4 temperature of supplying with heat exchanger are 20 ℃, and amount of supplied air is 30000m ³/ h, this air 4 feeds from heat exchanger top, forms three stage countercurrent heat exchange forms with flue gas and carries out heat exchange;

Step 3: heat exchange

Flue gas 1 by heat exchanger 2 bottoms feed, top discharges, be covered with air tubulation 7 in the exhaust gases passes, air 4 is fed by heat exchanger top tubulation 7, from top to bottom through after three grades of tubulation 7 heat exchanges, flue-gas temperature 5 is reduced to 390 ℃, air 4 temperature are elevated to 380 ℃, and the flue gas 6 after the cooling is discharged by the top of heat exchanger 2.

Present embodiment roaster coal supply amount 3.3% is equivalent to coal supply amount 1.122t/h, saves coal consumption and amounts to 4.5 yuan/ton of RMB, 1,200,000 yuan of year saving production costs.

Embodiment 3:

As shown in Figure 1, concrete steps of the present invention are as follows:

Step 1: flue gas is introduced heat exchanger

Flue gas 1 temperature that roaster produces is 720 ℃, exhaust gas volumn 33000m ³/ h under the high temperature draught fan effect, is introduced this flue gas 1 by the bottom of heat exchanger 2, the dust that contains in the flue gas is through gravity settling chamber and return roaster by overflow spiral organ 3;

Step 2: air infeeds heat exchanger

Air 4 temperature of supplying with heat exchanger are 20 ℃, and amount of supplied air is 30500m ³/ h, this air 4 feeds from heat exchanger top, forms three stage countercurrent heat exchange forms with flue gas and carries out heat exchange;

Step 3: heat exchange

Flue gas 1 by heat exchanger 2 bottoms feed, top discharges, be covered with air tubulation 7 in the exhaust gases passes, air 4 is fed by heat exchanger top tubulation 7, from top to bottom through after the 7 bundle heat exchanges of three grades of tubulations, flue-gas temperature 5 is reduced to 400 ℃, air 4 temperature are elevated to 360 ℃, and the flue gas 6 after the cooling is discharged by the top of heat exchanger 2.

Present embodiment roaster coal supply amount 2.8% is equivalent to coal supply amount 1.176t/h, saves coal consumption and amounts to 5 yuan/ton of RMB, 1,650,000 yuan of year saving production costs.

Claims

1, a kind of method of converting to hot air from flue gas in baking furnace, it is characterized in that: concrete steps are:

Step 1: flue gas is introduced heat exchanger

The flue-gas temperature that roaster produces is higher, and at 600 ℃～750 ℃, heat content is very big, contains certain dust in the flue gas, requires heat exchanger must possess the deashing function;

Step 2: air infeeds heat exchanger

Step 3: heat exchange

Flue gas feeds bottom heat exchanger, discharge on top, be covered with the air tubulation in the exhaust gases passes, air is fed by heat exchanger top tubulation, from top to bottom through after the heat exchange of three grades of tubulation bundles, 600 ℃～750 ℃ flue-gas temperature drops to 350 ℃～400 ℃, and air themperature is elevated to 300 ℃～400 ℃ by 20 ℃ under the natural conditions.