RU2392059C1 - Method for cleaning of gases from dust - Google Patents

Abstract

FIELD: heat power engineering.

SUBSTANCE: invention relates to technology of gases cleaning from dust in heat power engineering, ferrous and non-ferrous metallurgy. Method for cleaning of gases from dust includes supplying cleaned gas into cyclone with upper axial exhaust nozzle, cleaning of gas from dust due to action of centrifugal forces in reciprocal motion of rotary flow top-down with rotation of cleaned flow upward, collection of captured dust flow in dust collector, supplying flow of auxiliary coagulating liquid flow into cyclone, at the same time liquid is sprayed in dust collector in the form of jets, oriented for flow of captured dust, with production of captured dust and liquid mixture, afterwards mixture is briquetted at roller press installed in lower part of dust collector.

EFFECT: increased extent of gases cleaning from dust and expansion of method functionality.

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Description

The invention relates to a technology for cleaning gases from dust in the power system, ferrous and non-ferrous metallurgy.

There is a method of cleaning gases from dust, which consists in the tangential supply of dusty gas, cleaning gas from dust due to centrifugal forces, separating dust from gas in the sweep zone of the purified gas, collecting dust flows in a dust collector (see Dust collection in metallurgy. Reference / B .M. Aleshina, A.Yu. Waldberg, G.M. Gordon, etc. M .: Metallurgy, 1984, p. 48-52). The disadvantage of this method of cleaning gases from dust is the low efficiency of the dust collection process.

The closest in technical essence and the achieved result is a method of cleaning gases from dust, including introducing a gas to be cleaned into a cyclone with an upper axial exhaust pipe, cleaning gas from dust due to the action of centrifugal forces during translational movement of a rotating stream from top to bottom with a turn of the cleaned stream up, collection the flow of trapped dust in the dust collector, the supply of auxiliary coagulating liquid to the cyclone (see Patent No. 22259240, Russia, IPC 7 B04C 5/18, filed November 24, 2004).

The disadvantage of this method of gas purification is the low degree of gas purification from dust. This is due to the fact that the streams of captured dust enter the dust collector in the form of a loose dry mass, which is easily captured by the reverse gas flow in the headland. Humidification of dust flows by coagulating liquid in the reversal zone and in the dust collector is a useful action aimed at increasing the efficiency of dust collection, but the resulting mixture of dust and liquid in a stationary (static) state coalesces and forms a dense mass in the dust collector, which is difficult to unload from it. In order to ensure efficient dust collection and removal of trapped dust from the dust collector, it is necessary to irrigate it with coagulating liquid and subsequent briquetting of the trapped dust stream.

The objective of the invention is to increase the degree of purification of gases from dust and the expansion of technological capabilities of the method of purification of gases from dust.

This object is achieved in that in a method for cleaning gases from dust, including introducing a gas to be cleaned into a cyclone with an upper axial exhaust pipe, cleaning gas from dust due to the action of centrifugal forces during the forward movement of a rotating stream from top to bottom with a turn of the cleaned stream upward, collecting the flow caught dust in the dust collector, the flow of auxiliary coagulating liquid into the cyclone, the coagulating liquid is sprayed in the dust collector in the form of jets oriented to the captured dust flow, with the formation of a mixture of trapped dust and liquid, after which the mixture is briquetted on a roller press installed in the lower part of the dust collector.

The invention consists in the following. Coagulating liquid is sprayed in a dust collector in the form of jets oriented to the stream of captured dust, with the formation of a mixture of captured dust and coagulating liquid. Coagulating liquid is supplied under pressure in the form of jets oriented at an acute angle (30-45 °) to the streams of trapped dust. This ensures uniform dust humidification and acceleration of dust flows by dynamic pressure of the jets. The result is a mixture formation and accelerated transportation of the wet mixture to the loading unit of the roller press. After that, the wet mixture, consisting of trapped dust and liquid, is loaded into the gap between the rollers installed in the lower part of the dust collector and briquetted. The resulting briquettes are easily unloaded from the dust collector and are either sent to the dryer or recycled to consumers. When wetting the streams of captured dust, the capture of dust is completely eliminated by the reverse flow of the gas being cleaned, which increases the efficiency of dust collection. The mixture formed in the dust collector is briquetted to form briquettes ready for industrial disposal. This allows the mixture of dust and liquid in the form of briquettes to easily unload it from the dust collector. The organization of briquetting in the dust collector of the dust collector allows you to expand the technological capabilities of the device designed for cleaning gases from dust. Briquettes obtained in a cyclone can be used in technologies for the disposal of bulk industrial waste. Known binders are used as coagulating liquids: solutions of water glass, sulphite yeast brew (SDB), lime or cement milk. Their number depends on the type of dust caught, size and density. For briquetting dust in the proposed method for cleaning gases from dust, the content of the binder liquid, for example, SDB, should not exceed 5-6%, so as not to impair the flowability of the collected dust in the dust collector and to ensure its supply to the roller press.

Thus, due to the distinguishing features, the claimed method acquires new properties: effective coagulation of the trapped dust streams moving along the inclined surface of the dust collector with a binder liquid; dynamic acceleration and granulating rolling of the captured dust by jets of atomized coagulating liquid and orienting it to the loading unit of the roller press; the organization of briquetting streams of captured dust directly in the cyclone dust collector. These properties increase the efficiency of dust collection in the proposed method and expand its technological capabilities.

A method of cleaning gases from dust is implemented using the device shown in the drawing.

It contains a supply pipe 1, a housing 2, an exhaust pipe 3, a dust collector 4, a pipe 5 for supplying coagulating liquid, a roller press 6. During operation of the device, jets of coagulating liquid 7, streams of trapped dust 8, briquettes 9 are formed in the dust collector.

The method of gas purification is as follows. The dusty gas stream through the pipe 1 enters the housing 2, where the gases are cleaned from dust due to the action of centrifugal forces during the translational movement of the rotating stream from top to bottom. An annular pipe 5 of coagulating liquid is installed in the reversal zone of the gas to be cleaned. Nozzles are installed in the annular pipe 5 through which a coagulating liquid flows in the form of jets 7. The cleaned gas stream enters the environment through the nozzle 3. Streams of captured dust 8 enter the dust collector 4 and move to its lower part. The jets 7 evenly moisten the dust streams 8 and accelerate their movement to the lower part of the dust collector 4. During the movement of the dust streams, they mix with a finely divided coagulating liquid and form a mixture. The mixture of dust and liquid enters the loading unit of the roller press 6. During the rotation of the rollers (the drive is not shown conventionally), the press 6 briquettes the wet mixture and briquettes 9 are formed, which are sent for recycling to consumers. If necessary, the rollers are cleaned with cleaners (not shown in the diagram) of any known construction used in industry.

Example. The processing of gas dust cleaning method was carried out on a laboratory centrifugal dust collector with a diameter of 300 mm, equipped with a coagulating fluid supply system and a roller press, according to the given technological scheme. Sulphite yeast mash (SDB) was used as a coagulating liquid, the flow rate of which was changed from 2 g / s to 6 g / s. The inlet stream was dusted with ash and slurry particles measuring 0-0.1 mm. The obtained briquettes with a size of 5 × 15 mm were determined by compressive strength. The results of the experiment are presented in the table.

Table Coagulating fluid flow, g / s The dust collection efficiency of the method,% The strength of briquettes, kPa one 2 64.9 80 2 four 71.6 140 3 6 78,4 300 Prototype Data four 63.6 -

Experimental data show that the proposed method for cleaning gases from dust has a higher efficiency (1.3-14.8%) compared with the prototype and allows to obtain ash and slag briquettes based on SDB with a strength of 80-300 kPa.

Claims (1)

A method of cleaning gases from dust, including introducing the gas to be cleaned into a cyclone with an upper axial exhaust pipe, cleaning gas from dust due to the action of centrifugal forces during the translational movement of a rotating stream from top to bottom with a turn of the cleaned stream up, collecting a stream of trapped dust in a dust collector, feeding it into a cyclone auxiliary coagulating fluid flow, characterized in that the coagulating fluid is sprayed in a dust collector in the form of jets oriented to the captured dust flow, with the formation of a mixture of captured dust and liquid sti, after which the mixture is briquetted on a roller press installed in the lower part of the dust collector.

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