RU2142853C1 - Electric cyclone - Google Patents

Abstract

FIELD: applicable for dust catching, dust may be with any specific electric resistance. SUBSTANCE: the apparatus may be both of single and group modifications, which makes it possible to make the dust - catching system of any capacity for gas. The apparatus has a body, inlet connection, hopper, central pipe, corona-forming electrode and an exhaust pipe; the central pipe is made gas-permeable (for example, due to perforation in its peripheral surface), which makes it possible to increase the gas capacity, and has an adapter connected to the exhaust pipe through gas outlet pipe connections. EFFECT: enhanced efficiency of dust catching. 3 dwg, 1 tbl

Description

 The invention relates to dust collecting equipment, and more particularly to centrifugal-electric dust collectors, and can be used to clean gases from suspended particles in chemical, metallurgical, cement and other industries.

 Known dust collecting apparatus (GB 800345, B 01 C, 1958), which is an electric cyclone consisting of a housing, an inlet pipe, a hopper and a corona electrode made in the form of a spiral and located coaxially inside the housing. A dusty gas stream, entering the body through the inlet pipe, is cleaned under the combined action of centrifugal and electric fields. Such an apparatus can be manufactured for greater gas productivity.

 The disadvantage of this apparatus is that the gas inside the spiral is not subjected to electrical cleaning, which reduces the efficiency of dust collection.

 This disadvantage is eliminated in the closest to the proposed device (av. St. USSR 364346, B 03 C 3/16, 73), which is an electrocyclone (a combination of countercurrent cyclone and tubular electrostatic precipitator). It contains a housing with a central exhaust pipe, an inlet pipe, a hopper and a corona electrode, in which a dusty gas moving in a countercurrent circuit is cleaned: first under the influence of centrifugal field forces, and then in a corona discharge electric field. In order to increase the efficiency of fine dust capture, the corona electrode is placed coaxially in the central exhaust pipe.

 The disadvantage of this device is its low gas performance.

 The aim of this invention is to increase gas productivity with high dust collection efficiency.

 The goal is achieved by the fact that the central pipe is provided with perforations along its lateral surface and contains a nozzle below, consisting of a cone and a cylinder, the latter being connected to the exhaust pipe by gas exhaust pipes.

 The proposed electrocyclone, as well as the prototype, is a combination of a cyclone and an electrostatic precipitator combined in one housing. It contains a housing with a central pipe and a corona electrode located inside it, an inlet pipe, a hopper and an exhaust pipe. The gas productivity of the apparatus is determined by the gas velocity in the annular space between the housing and the central pipe and the cross-sectional area of this space.

 With an equal cross-sectional area of the annular space of the prototype and the proposed apparatus, the productivity of the latter can be increased due to a higher gas velocity in the upper cross-section (to perforations), since then, as you move down, a gradual outflow of gas from the annular space into the central pipe through its perforated wall. However, the hydraulic resistance of the proposed device does not increase compared with the prototype.

 High gas cleaning efficiency is achieved due to the ordered movement of compacted dust and gas. So, the nozzle at the bottom of the central pipe, consisting of a cone and a cylinder, prevents entrained dust from the lower part of the body into the exhaust pipe through an annular hole between the central and exhaust pipes. A small part of the gas (about 3%) enters the hopper with the dust, which helps it to pass through the annular openings between the body and the cone, the central and exhaust pipes. This part is discharged from the hopper through the exhaust pipes into the exhaust pipe due to the ejection effect of the gas in the latter. Before entering these nozzles, the gas, bending around the cone and cylinder, sharply changes its direction, being freed from the trapped dust. Thus, the nozzle and exhaust pipes provide for the removal of gas from the hopper without intersecting with the flow of dusting dust.

 The results of comparative tests of the prototype and the proposed apparatus are presented in the table, from which it can be seen that with different hydraulic resistances of the prototype and the proposed apparatus, the latter has a high gas performance with high dust collection efficiency.

 A comparative analysis of the proposed solution with the prototype shows that the proposed device is characterized by the presence of new structural elements - perforation in the central pipe and nozzles, which are connected to the exhaust pipe by exhaust pipes. Thus, the proposed device meets the criteria of the invention of "novelty."

 A comparison of the solution with other technical solutions shows that the use of once-through cyclones and electrostatic precipitators separately is known. However, in this technical solution, the combination of two dust collectors in one housing exhibits new properties - it allows to increase gas productivity while increasing the efficiency of dust collection.

 In FIG. 1 shows a diagram of a longitudinal section of the apparatus, FIG. 2 and FIG. 3 is a schematic cross-sectional view of the apparatus.

 The electric cyclone is a housing 1, equipped with an inlet pipe 2 at the top and a hopper 3 with a dust discharge fitting 4 at the bottom.

 Inside the housing 1, an electrode system is installed: precipitation - the central pipe 5 and corona - the rod 6 with discharge devices such as needles - 7. The corona electrode 6 is suspended on the insulator 8, which is closed on top of the insulator box 9. An exhaust pipe 10 passes through the hopper 3. The central pipe 5 contains a nozzle consisting of a housing 11 and a cylinder 12. The latter is connected to the exhaust pipe 10 by a gas outlet 13.

 Electrocyclone works as follows.

 The dusty gas stream enters the housing 1 through the exhaust pipe 2 and acquires a reciprocating movement down the housing 1 of the apparatus. In the annular space between the casing 1 and the central pipe 5, the main part of the dust, discarded by centrifugal force to the wall of the casing 1, moves down and enters the hopper 3 through the annular gap between the casing 1 and the cone 11. Further, the gas cleaning process from the fine dust remaining in it is organized as follows: the gas is directed from the periphery into the central pipe 5 towards the flow of gas ions moving from the corona electrode to the inner surface of the central pipe 5. At the same time, inside the central pipe 5 a series of dust particles and their deposition under the influence of electrostatic field forces on the inner surface. Thus, the central pipe 5 performs the function of a precipitation electrode. Due to the downward flow of gas, dust particles deposited on the inner surface of the central pipe 5 are moved down to the dust-discharge ring hole between the central pipe 5 and the exhaust pipe 10. Through this ring hole, captured dust enters the space between the housing 11 and the exhaust pipe 10 and is poured into the hopper 3 A part of the gas entering the hopper 3 is discharged from the latter through the exhaust pipes 13 into the exhaust pipe 10. The generation of ions inside the central pipe 5 is due to the intense coronary with a number of needles 7 arranged on the rod 6. The last hanging on the insulator 8 that closes the box insulator 9.

 The collected dust from the hopper 3 is discharged through the dust discharge fitting 4.

 Inside the central pipe 5, the gas maintains a rotational movement, which contributes to the cooling of the particles.

Literature
1. England patent N 800345, B 01 d, 1958.

 2. USSR Author's Certificate N 364346, B 03 C 3/16, 1973.

Claims (1)

 An electric cyclone for cleaning gases from dust, comprising a housing with a central pipe and a corona electrode located inside it, an inlet pipe, a hopper, an exhaust pipe, characterized in that the central pipe is provided with perforations along its side surface and contains a nozzle at the bottom consisting of a cone and a cylinder and the latter is connected to the exhaust pipe by exhaust pipes.

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