CN1010345B - Device for purification of combustion gas - Google Patents

Abstract

The present invention relates to combustion equipment 10. a pair of heat exchangers 14 of the combustion equipment 10 respectively have storage space 15 containing alkaline granules so as to alternately make combusted gas and air pass through the storage space. Residual heat carried by the combusted gas is absorbed by the granules, moisture contents in the gas are condensed on the granules, sulfur dioxide in the combusted gas reacts with magnetic materials so as to generate calcium sulfite, and smoke particles and other pollutants in the gas can be caught by humid granules. After valve gates 21 and 24 are rearranged, the air is preheated by passing through the granules; heated air is guided to a combustor 11, a granule regenerator 27 or is transmitted to an exhaust conduit 25 by a conduit 33, the granules are transmitted to the regenerator 27 so as to carry out mechanical treatment after a certain operating time, and separated calcium sulphate and powder dust particles are preferably and simultaneously heated.

Description

Device for purification of combustion gas

Contain a certain amount of heat energy from the burnt gas in the stove, this heat energy can not be utilized in combustion apparatus or conventional heat exchanger again.Wherein also contain for example corrosive substance, dust granule and other pollutant such as sulphur compound, these materials are difficult to remove, and may cause environmental pollution.

The objective of the invention is to propose a kind of equipment, the amount of residual heat will that it can effectively utilize in the burnt gas adds hot-air, and simultaneously can also the purifying burnt gas, comprising in and corrosivity one acid compound, collect the dust that gas carries secretly, heavy metal and some the gaseous mercury compound that particle adheres to.The product that stays is a kind of chemically stable compound, can easily be handled.

The present invention includes a regenerative heat exchanger that is connected on the equipment that produces dusty gas, said heat exchanger has at least two groups to be used alternatingly, each group all has the storage space that holds heat storage, and is equipped with the passage that burnt gas and air are passed through.The invention is characterized in that heat storage comprises a certain amount of alkali grain, every group of heat exchanger bottom is equipped with some passages, there are other passages on its top, reversal valve is installed in addition air-flow is directed to storage space, so that contaminated gas is passed through along a direction, and air alternately passes through along opposite direction, wherein every group of heat exchanger and the gas admission passage that is connected thereto are arranged to such an extent that make temperature in the storage space, are reduced to below the dew point of institute's water content in the burnt gas.

These moisture content can adhere to heavy metal and some gaseous mercury compound of flue dust, particle adhesion, and can promote the reaction between sulfur dioxide and the alkali grain.

The passage that leads to storage space is preferably arranged to such an extent that make burnt gas from top to bottom by this storage space, and air is then from bottom to top by this storage space.Perhaps passage is arranged to such an extent that burnt gas is outwards flow through from storage space inside, air then inwardly flows through from the storage space outside.This storage space preferably is equipped with internal partition wall with holes, and storage space is divided into two chambers at least, can make burnt gas and air make lateral flow basically respectively.

This heat exchanger is to mediate a settlement its conveying device that be returned to storage space combined from storage space to scavenge unit with the device of removing the alkali grain superficial layer and the inefficacy material of this superficial layer being removed and with particle preferably.This scavenge unit preferably comprises the heated cylinder of a rotation, at other pipeline of receiving unit hot-air is housed, so that chemical reaction is proceeded, further is oxidized to calcium sulfate so as to the calcium sulfite that will adhere on the particle.And calcium sulfate is stable, inertia residual product, and it can be processed and have tangible inconvenience.When cylinder rotated, chemically the particle surface layer of Shi Xiaoing was ground off, and therefore can obtain fresh material, these particles is returned in the heat exchanger reuses.

The heated air of part can be transported to the burner of stove, in burner, produce the burnt gas that pollutes.

Under certain operating condition, in heat exchanger, produce excessive heated air, preferably this excessive air that is heated is transported to gas emission pipe, so that improve the climb performance of burnt gas.

This heat exchanger preferably is equipped with the device of measuring content of sulfur dioxide in the gas-flow, exports or sends into particle to storage space so that control from storage space for the response intensity value that keeps the alkalescence contact be scheduled to.

Hereinafter with reference to accompanying drawing the present invention is described, wherein

Fig. 1 is the profile of a heat exchanger of the present invention, and this heat exchanger is connected on stove and the regenerating unit, and stove and regenerating unit schematically illustrate, and

Fig. 2-4 schematically illustrates the storage space and the different situations of arranging of passage wherein.

In Fig. 1,10 expressions constitute the stove of boiler component with reference to label, be equipped with gaseous fuel, liquid fuel or solid fuel burner 11 on it, to wherein supplying with hot-air, this hot-air is provided by burnt gas clarifier-heat exchanger via conduit 12.Burnt gas conduit by label 13 expressions is directly connected on boiler-stove.

In order to utilize the amount of residual heat will in the burnt gas again, make wherein unwanted effluent become harmless material, be equipped with heat exchanger-filter 14.In these heat exchangers, replace, thereby remove to add hot-air with the amount of residual heat will that burnt gas is emitted by burnt gas and air.Therefore this equipment comprises unit like two categories at least, but has only drawn among this accompanying drawing one group.Preferably have Unit the 3rd as deposit, can cut off one group of cleaning and general overhaul so successively.

The shape of heat exchanger unit can change, and its size depends on the ability of combustion apparatus certainly.A kind of embodiment preferred comprises a kind of tower structure, and its base size ratio is highly little, and impales a storage space 15 that is filled with alkali grain 16.In the storage space the broken lime stone of filling or similarly material be favourable, but also can be with the rubble with basic surface clad or some other carrier.

In illustrated specific embodiments, storage space is equipped with a base plate 17, and the slype 18 that this base plate is continuous along the longitudinal from the center is downward-sloping towards outlet 19 to both sides.Outlet can be closed dead by cover plate 20, and near slype 18 clack valve 21 is installed.

Storage space 15 is equipped with internal partition wall 22 and external partition wall 23 respectively.This internal partition wall is installed in the top of slype 18, and forms wedge gap above slype.External partition wall 23 is parallel with the internal partition wall, so that remain with wedge gap between baffle wall and the equipment sidewall outside.

Be connected with the air conduit 12 that leads to burner and gas conduct pipe 13 respectively at the ridged top of equipment, and the top also is equipped with second clack valve 24.Final waste gas is by 25 expressions, and it is discharged from the space that is under the base plate 17.

Purpose is respectively alternately by burnt gas and air in this storage space, and in an equipment, use simultaneously under the situation of two unit heat exchangers, supply with burnt gas in the unit with heating particle wherein, while air supply in another unit, the particle that makes it to be heated in advance heats.After certain operating time, exchange this two kinds of air-flows.

Under mode of operation shown in the drawings, heat exchanger 14 bubbling airs, the heat that utilizes the earlier stage particle to be absorbed.

Air enters into a side that is in space under the base plate 17 through duct 26, and duct 26 is arranged on the opposite of the passage that connects burnt gas conduit 25.In this accompanying drawing of swing clack valve 21(is to be flapped toward the right side) so that duct 26 is communicated with the space that is between the internal partition wall 22 by slype 18.

Because this design of baffle wall, air (and burnt gas afterwards) will be essentially horizontally by having the stratum granulosum of substantially uniform thickness.

Rotate the clack valve 24 on top, make it to cut off burnt gas conduit 13, but but keep connecting air conduit.When this two clack valve 24 and 21 was transformed into its relative position, burnt gas entered with outflow pathway and is opened respectively, and meanwhile air flue is turned off.

In burnt gas, always have certain moisture content, and the burnt gas outlet temperature is very high in legacy equipment, the phenomenon of condensing of moisture content can not take place on the area of heating surface of boiler.This means and in waste gas, have considerable amount of residual heat will.

According to the present invention the passage before storage space 15 and the burnt gas outlet is suitably arranged, make water vapour in storage space generation condensation.The moisture content that condenses has like this promoted to generate between sulfur dioxide composition in the burnt gas and the alkali grain reaction of calcium sulfite greatly.In most zone of storage space, ubiquity has the particle of moist and viscosity, and this makes them have the ability of very high seizure flue dust, and catches the heavy metal of particle adhesion and the ability of some gaseous mercury compound.

Except preheated air, can also make burnt gas obtain good purifying.When air afterwards by these particles and when being heated, the calcium sulfite that begins to generate generates more stable end product calcium sulfate to I haven't seen you for ages by partly further oxidation.

After using a period of time, the superficial layer reactivity of these particles will reduce.These particulate matters are slowly moved down in heat exchanger,, supply with new particle simultaneously at the top with reactivity so that remove the particle of inefficacy from its bottom.

In accompanying drawing 1, reference marker 27 representatives are encapsulated in the rotatable cylinder in the shell (not shown), supply with particle with some suitable conveying device 28 in cylinder.Carry particle one transfer unit to represent with some similar device from the opposite side of heat exchanger by dotted line 29.

Regeneration and mechanical removal particle surface layer in cylinder 27.For example use the cylinder have the hole, all or partially the epidermal area of particle is ground off and separate.Thereby in these particles, powdered material and smaller particles are removed, meanwhile these particles of handling are sent in cylinder by means of the proper device (not shown).

The device of eliminating particle epidermal area preferably two heat exchangers is public, and excessive particle wherein is housed, so that the state that the storage space of two heat exchangers remains full of when handling particle.

Utilize suitable equipment 30, the particle that for example utilizes bucket elevator or conveying worm to handle sends back to storage space.Instrument 31 is connected on the combustion gas waste gas, and this instrument and equipment detects the circulation of from the burnt gas that heat exchanger is discharged content of sulfur dioxide and control particle, so that make content of sulfur dioxide be no more than predetermined value.

The thermal content of burnt gas, when feeding air in the burner usually above heating the thermal content that can utilize.Remaining air can be delivered in the cylinder 27 by conduit 32.Send into the hot-air in the cylinder, promote the calcium sulfite on the particle to generate the oxidation of calcium sulfate, and calcium sulfate is a kind of stable residual product, it can simply be removed from particle by mechanical wear or washing.May carry a certain amount of dust secretly from the air that cylinder is discharged, preferably it be delivered to burnt gas conduit 13 or directly send in the heat exchanger 14, so that contaminated air must be removed dust by particle storage layer.

At some in particular cases, when not needing excess air in the scavenge unit 27, can there be the conduit 33 of nozzle 34 that the part air is transported in the burnt gas waste gas 25 by terminal, so that improve the climb performance of burnt gas.

Accompanying drawing 2-4 illustrative particle holds, and connection gas conduct pipe thereon and some specific embodiments that substitutes of air conduit.In each figure, the air approach represents that with solid line combustion gas body approach with dashed lines is represented.

The embodiment of accompanying drawing 2 basically with accompanying drawing 1 quite, but the shape of storage space 15a is down " V " font.Baffle wall 22a and 23a tilt approximately quite or just over the static natural angle of rest (repose) of these particles.

Here the relatively little surface of cold side is exposed to still and may has in corrosive burnt gas.

What accompanying drawing 3 was represented is a kind of remodeling, and its mesospore 22b and 23b are limiting storage space, and it just is being shaped as " V " font.Here, corresponding increase is compared with that embodiment of front in the cold side surface, but on the other hand, has only less surface in hot side, therefore must be in addition heat insulation to prevent that condensation from taking place.

As being seen from accompanying drawing 4, can make that baffle wall 22c is vertical with 23c to be placed, so just obtained two parallel accumulation of heat tube 15c, these two accumulation of heat tubes both can separate fully, also can interlink by the device of supplying with and draw off particle.Burnt gas outwards passes through internally, and air then inwardly passes through from the outside.

The specific embodiments of showing in description and the accompanying drawing is only considered as embodiment above, and its component parts can change in accompanying drawing following claim scope in many ways.Storage space can be made single logical tube, promptly be confined between two baffle wall, and it be centroclinal a side direction can be made in the end 17.These measures will be guaranteed sending into of particle and draw off simpler.

Can use shaking screen or some similar equipment to replace revolving cylinder 27, particle is subjected to the influence of mechanical wear and air effect in these equipment, removes smaller particles simultaneously.

The present invention is as using with stove and describing, and still clearly, the present invention also can unite use with many industrial process of the dusty gas that can produce heat.

Claims (5)

1, the equipment of a kind of preheated air and purification burnt gas, comprising a kind of regenerative heat exchanger that produces on the dusty gas device that is connected to, this heat exchanger contains at least two similar unit (14) that are used alternatingly respectively when gas purification and air preheat, each unit has the storage space (15) that holds heat storage, this heat exchanger is equipped with the water conservancy diversion reversal valve (21 of gas and air, 24), make gas and air can pass through storage space (15) in the opposite direction

It is characterized in that:

Each storage space (15) is equipped with passage (25,26) in its underpart, be equipped with passage (12,13) in the top, and fills a certain amount of alkali particle (16),

Each unit (14) is installed into the interior temperature of the feasible storage space that is connected with the gas admission passage (13) that is connected thereto, is lowered to be lower than below the burnt gas dew point that feeds often,

Each storage space (15) is equipped with internal partition wall (22,23) with holes, and the space is separated into two chambers at least, and make gas and air make substantial lateral respectively and flow with respect to the particle in the storage space,

This equipment also has the device (27) of removing the alkali grain superficial layer and the material of surface failure being removed, and the device that said particle is carried and turned back to said storage space to said device from storage space (15).

2,, it is characterized in that scavenge unit (27) comprises the hot cylinder of a rotation according to the equipment of claim 1.

3,, it is characterized in that said scavenge unit (27) is equipped with the passage (32) of receiving unit heated air according to the equipment of claim 1 or 2.

4, according to the equipment of aforementioned arbitrary claim, it is characterized in that being equipped with the instrument (31) of measuring content of sulfur dioxide in the burnt gas waste gas, in order to control from storage space and the particle carried to storage space, so that keep the response intensity of its alkaline contact surface to have predetermined numerical value.

5,, it is characterized in that the air that any amount is heated is transported to the conduit (33) of burnt gas blast pipe according to the equipment of claim 4.

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