RU2781925C2 - Cyclone element of multicyclone - Google Patents

Abstract

FIELD: multicyclones.

SUBSTANCE: invention relates to a cyclone element of a multicyclone. The cyclone element of the multicyclone includes a one-piece forged body 1 with a cylindrical part 2 and a tapering part 3, a guide vane 4 and an exhaust pipe 5. The length of the tapered part 2 is at least half the length of the cylindrical part 1. The tapering part of the body is made in the form of a shell of rotation with a central outlet hole. The profile of the walls of the tapering part is matched with the profile of the walls of the cylindrical part. The guide apparatus 4 is made in the form of two semi-volutes, the inlets 6 of which are located parallel to the axis of the exhaust pipe and directed in opposite directions. The guide vane 4 covers the exhaust pipe 5 and is fixed on the cylindrical part of the body 1. The length of the tapering part of the body is related to the characteristics of the gas flow being cleaned, the inner diameter of the cylindrical part of the body and the outer diameter of the exhaust pipe by the ratio:

,

where: "*" - the index of linear dimensions, expressed in fractions of the inner diameter of the cylindrical part of the body D,

is the length of the tapering part of the body;

is outer diameter of the exhaust pipe; d and d* - dust particle diameter in mm and fractions of the inner diameter of the cylindrical part of the housing; μ - dynamic viscosity of gas, Pa⋅s; ρ is the density of a dust particle, kg/m³; and t is the tangential velocity of a dust particle, taken equal to the velocity of the gas flow at the inlet to the cylindrical part of the body, m/s. The proposed ratios of the dimensions of the cyclone element provide a reduction in the mass, material consumption and labor intensity of its manufacture from standard pipes and exclude the ingress of liquid and dust into the ascending stream of purified gas.

EFFECT: reducing the consumption of resources in the production of cyclone elements and increasing the reliability of gas-pumping equipment of compressor stations.

5 cl, 3 dwg

Description

The invention relates to the field of gas purification using gravitational, inertial and centrifugal forces, namely, to multicyclones (also referred to as battery cyclones), and is intended for compressor stations of main gas pipelines.

The multicyclone is an inertial dust collecting apparatus, including a plurality of cyclone elements connected in parallel, combined in one housing and having a common gas supply and exhaust, as well as a collection bin. See Kropp L.D., Bronstein A.Sh. Operation of battery cyclones. - Moscow; Leningrad: Energy, 1964. - pp. 28-32, 62-71.

The cyclone element of the multicyclone includes a housing with cylindrical and tapering parts, a guide vane and an exhaust pipe. The lengths of the cylindrical and tapering parts of the housing are essentially the same. The tapering part of the housing is made in the form of a conical shell with a central outlet. The guide apparatus of screw or socket type is installed in the cylindrical part of the housing between the walls of the housing and the exhaust pipe. The details of the cyclone element are made of sheet steel and connected by welds.

Known cyclone element is not adapted to the separation of liquid entering the multicyclone with gas and settling on the inner walls of the housing in the form of creeping layers. Sliding along the inner conical walls of the tapering part of the housing, the liquid enters the zone of low pressure and is sucked in by the ascending gas flow. Sliding down the outer walls of the exhaust pipe “... Layers of fluid flow to the exhaust pipe opening, from where they are easily entrained by gas. The degree of creep depends on the properties of the liquid - its surface tension and viscosity, so, for example, oil is carried away faster than water. See Straus V. Industrial gas cleaning: TRANS. from English. - M.: Chemistry, 1981. - pp. 291-295.

In addition, in the tapered conical part of the housing, dust and liquid particles slip from the downward gas flow into the upward one. The particle is affected by the resistance force of the swirling gas flow, which carries the particle along a downward trajectory in the form of a tapering spiral, and the centrifugal force, which directs the particle to the conical wall. The motion of the particle is accompanied by counter impacts on the conical wall and rebounds of the particles to the axis of the cone. Near the outlet, the radial components of the flow resistance and impact forces may be sufficient to overcome the centrifugal force and slip the particle into the upward gas flow. The phenomenon of particle slippage into the updraft limits the purification efficiency.

Known cyclone element, cast from high quality cast iron. See Straus V. Industrial gas cleaning: TRANS. from English. - M.: Chemistry, 1981. - pp. 291-295. One-piece cyclonic element contains a cylindrical part, a tapered part, a guide vane and an exhaust pipe. The length of the tapering part is at least half the length of the cylindrical part. The tapering part is made in the form of a parabolic shell of revolution with a central outlet. The profile of the walls of the tapered part is matched with the profile of the walls of the cylindrical part. The rosette-type guide apparatus is made between the cylindrical walls of the housing and the exhaust pipe.

In the elongated cylindrical part of the one-piece cast cyclone element, the layers of the deposited liquid slide into the tapered part outside the low pressure zone. The resistance force of the swirling gas flow carries the dust particle along a downward trajectory in the form of a cylindrical spiral. Centrifugal force directs liquid and dust particles to the cyclone wall. Dust and liquid particles are concentrated in the near-wall layer of the gas flow. The force of tangential impacts against the cylindrical wall is not sufficient for particles to slip into the ascending gas flow. In the short tapering part, the direction of the gas flow changes to the opposite, and the dust and liquid concentrated in the near-wall layer of the cylindrical part are removed through the central hole under the action of gravitational, inertial and centrifugal forces. The described cyclone element provides better gas purification relative to the first analogue, but retains the leakage of the settled liquid to the outlet pipe opening and the slippage of dust particles from the descending gas flow to the ascending one, due to the high velocity of the near-wall gas layer.

Closest to the proposed technical solution, taken as a prototype, the cyclone element of the multicyclone ANDERSON Multi-Cyclone Separator (AMCS) from Clark-Reliance Corporation. See AN-DERSON™ Bulletin. A Division Of The Clark-Reliance Corporation. AMCS Series Multi-Cyclone Separator. Section: A100. Bulletin: A100.45. Date: 3/1/98. Supersedes: 3/79., as well as content on the company's website: URL: https://www.crfiltrationsolu-tions.com/anderson-separators-gas-applications (Accessed: 01/31/2022).

The AMCS cyclone element consists of a cast housing and an exhaust pipe. Cast housing and exhaust pipe are welded together. The cast body contains a cylindrical part, a tapering part and a guide vane. The length of the tapering part is at least half the length of the cylindrical part. The tapering part of the cast housing is made in the form of a hemispherical shell with a central outlet. The profile of the walls of the tapered part is matched with the profile of the walls of the cylindrical part. The guide apparatus is made in the form of two semi-volutes covering the exhaust pipe from below. The entrances of the semi-volutes are parallel to the axis of the exhaust pipe and directed in opposite directions.

The location of the entrances of the semi-volutes prevents the liquid settled on the exhaust pipe from flowing into the internal cavity of the cyclone element. In the elongated cylindrical part of the body of the cyclone element, the layers of the deposited liquid slide into the converging part outside the zone of low pressure. The resistance force of the swirling gas flow carries the dust particle along a downward trajectory in the form of a cylindrical spiral. Centrifugal force directs liquid and dust particles to the cyclone wall. Dust and liquid particles are concentrated in the near-wall layer of the gas flow. The force of tangential impacts against the cylindrical wall is not enough for dust particles to slip into the ascending gas flow. In the short tapering part, the direction of the gas flow changes to the opposite, and the dust and liquid concentrated in the near-wall layer of the cylindrical part are removed through the central hole under the action of gravitational, inertial and centrifugal forces.

According to the manufacturer, the cyclonic elements of the AMCS multicyclone remove 100% of liquid and solid particles with a size of 8.0 microns or more and 99% of all particles with a size of 5-8 microns at the pressure and gas flow parameters specified by the manufacturer. However, changing the parameters of pressure and gas flow leads to a decrease in the cleaning efficiency of both the prototype and all the analogues discussed above. As a result, at partial operating modes of the multicyclone, the efficiency of gas purification in the cyclone element is reduced.

Cyclone elements and their bodies with a tapered part in the form of a parabolic or hemispherical shell are cast and are characterized by a greater mass, material consumption and labor intensity of production compared to analogues with a tapered tapered part made of sheet material.

Problems solved by the invention:

- reduce the weight, material consumption and labor intensity of the cyclone element;

- increase the efficiency of gas purification when changing the parameters of pressure and gas flow.

The technical result from the use of the invention:

- reduction of resource consumption in the production of cyclone elements.

- increasing the reliability of gas-pumping equipment of compressor stations.

The invention is implemented in several versions.

1st execution.

The cyclone element of the multicyclone includes a housing with cylindrical and tapering parts, a guide vane and an exhaust pipe. The length of the tapering part is at least half the length of the cylindrical part. The tapering part is made in the form of a shell of revolution with an arcuate profile of the walls and a central outlet. The profile of the walls of the tapered part is matched with the profile of the walls of the cylindrical part. The guide apparatus is made in the form of two semi-volutes, the inlets of which are located parallel to the axis of the exhaust pipe and directed in opposite directions. The guide apparatus covers the exhaust pipe and is fixed on the body.

To solve the problem, the length of the tapering part of the housing is related to the parameters of the gas flow being cleaned, the inner diameter of the cylindrical part of the housing and the outer diameter of the exhaust pipe in the form of the ratio:

- длина сужающейся части корпуса;

- наружный диаметр выхлопной трубы; d и d* - диаметр частицы пыли в мм и долях внутреннего диаметра цилиндрической части корпуса; μ - динамическая вязкость газа, Па⋅сек.; ρ - плотность частицы пыли, кг/м³; и_t - тангенциальная скорость частицы пыли, принятая равной скорости потока газа на входе в цилиндрическую часть корпуса, м/сек.where: "*" - the index of linear dimensions, expressed in fractions of the inner diameter of the cylindrical part of the body (see dimension B in Fig. 1),

- the length of the tapering part of the body;

- outer diameter of the exhaust pipe; d and d* - dust particle diameter in mm and fractions of the inner diameter of the cylindrical part of the housing; μ - dynamic viscosity of gas, Pa⋅sec.; ρ is the density of dust particles, kg/m ³ ; and _t is the tangential velocity of a dust particle, taken equal to the gas flow velocity at the inlet to the cylindrical part of the body, m/s.

The expression in parentheses contains the parameters of the gas flow to be cleaned and has its own meaning for each field.

Dimensionless linear quantities with index "*" allow using relation (1) and creating geometrically similar cyclone elements for different gas flow rates. The rationale for relation (1) is presented in the description of an exemplary embodiment of the invention.

Version 1 reduces the weight, material consumption and labor intensity of cyclone elements due to the use of blanks from standard rolled tubing for the body and exhaust pipe. The length of the tapering part that satisfies relation (1) excludes the influence of the discreteness of standard pipe sizes on the efficiency of gas purification.

2nd execution.

Cyclone element of the multicyclone in version 1, characterized in that the profile of the inner wall of the tapering part of the housing is made by an arc of a circle, the radius of which is essentially determined by the ratio:

- радиус дуги окружности профиля; α - угол начала скатывания отделенных частиц жидкости под собственной тяжестью по стенкам сужающейся части, см. Зимон А.Д. Адгезия жидкости и смачивание. М., «Химия», 1974. 416 с. С. 97-100.where:

- radius of the profile circle arc; α - the angle of the beginning of the rolling of the separated particles of the liquid under its own weight along the walls of the tapering part, see Zimon A.D. Liquid adhesion and wetting. M., "Chemistry", 1974. 416 p. pp. 97-100.

Execution 2 provides liquid particles rolling from the inner wall of the converging part under its own weight and sufficient concavity of the inner wall to prevent dust and liquid particles from entering the upward flow. The design increases the efficiency of gas purification at partial operating modes of the multicyclone.

3rd execution.

The cyclone element of the multicyclone in execution 2, characterized in that the profile of the inner wall of the tapering part is made by an arc of a circle, the radius of which is essentially determined by the relations:

at:

Execution 3 provides the technological possibility of defect-free manufacturing of a one-piece forged body of a cyclone element in a swaging die from a single tubular billet. See Forging and stamping: Handbook: In 4 vols. 4. Sheet stamping / Ed. HELL. Matveeva; Ed. advice: E.I. Semenov (prev) and others - M .: Mashinostroenie, 1985-1987. - 544 p. Execution reduces the mass of materials and labor intensity of the cyclone element.

4th execution.

Cyclone element of the multicyclone in one of the versions 1, 2, 3, characterized in that the tapering part of the housing is made with an annular step around the central outlet.

The annular stage increases the cross-sectional area of the gas flow, which leads to a local drop in the velocity of the near-wall layer and the radial component of the flow resistance force. The drop in velocity of the near-wall layer already saturated with dust and liquid prevents particles from slipping into the ascending flow of purified gas. The axial component of the downward flow resistance force, centrifugal forces, inertial and gravitational forces press the particles losing speed to the surface of the stage and divert them into the central hole. The design increases the efficiency of gas cleaning.

5th execution.

Cyclone element of the multicyclone in one of the versions 1, 2, 3, 4, characterized in that the semi-volutes of the guide vane are made in the form of curved cylindrical shells fixed between two oval flanges, the cylindrical shells and flanges are made of sheet material and connected by welds.

Version 5 reduces the weight, material consumption and labor intensity of cyclone elements due to the shaping of parts from sheet material, the use of programmable laser cutting and bending equipment.

In FIG. 1 is a general view of a preferred design of the cyclone element, FIG. 2 - geometrical parameters of relation (1), in Fig. 3 - remote element A in Fig. 1 indicating the forces acting on the separated dust particle and its speed.

Relation (1) was obtained from the analysis of the motion of a dust particle in the converging part of the cyclone element.

A dust particle is affected by the gravitational force, the resistance force of the swirling gas flow, which carries the particle along a downward trajectory in the form of a narrowing spiral, and the centrifugal force

The radial component of the gas flow resistance force is determined by the Stokes formula:

where: F _S - gas flow resistance force, N; and _R is the radial velocity of the gas flow in the converging part of the cyclone element, m/sec.

Centrifugal force:

where: F _c - centrifugal force, N.

The radial gas flow rate is determined from the condition of equality of gas flow rates at the inlet to the cylindrical part of the cyclone element body and in the cylindrical section of the tapering part with a diameter D _e and length L _e :

where: Q _c - gas flow rate at the inlet to the cylindrical part of the body, m ³ / sec. Q _S - gas flow rate in a cylindrical section with a diameter D _e and length L _e , m ³ /sec.

From (7)-(9) follows:

To prevent dust particles from entering the ascending gas flow, on the circumference of the entrance to the narrowing flow with a diameter D _e , the centrifugal force must be greater than the resistance force of the gas flow:

From (5), (6), (10), (11) the relationship between the geometric parameters of the cyclone element and the parameters of the gas being purified is established:

After representing the linear dimensions of the left side (12) in fractions of the inner diameter of the cylindrical part of the body (by dividing the numerator and denominator of the left side by D), the relationship between the geometric parameters of the cyclone element and the parameters of the gas being purified was obtained in a generalized dimensionless form:

From (13) relation (1) follows for the length of the tapered part.

The preferred design of the cyclone element of the multicyclone includes the features of all the described designs. The cyclone element of the multicyclone includes a one-piece forged body 1 with a cylindrical part 2 and a tapering part 3, a guide vane 4 and an exhaust pipe 5. The body 1, the guide vane 4 and the exhaust pipe 5 are connected by welds. The semi-volutes of the guide apparatus are made in the form of curved cylindrical shells 6 fixed between two oval flanges 7. Cylindrical shells and flanges are made of sheet material and connected by welds. The entrances of 8 semi-snails of the guide vanes are parallel to the axis of the exhaust pipe and directed in opposite directions. The guide apparatus 4 covers the exhaust pipe 5 and is fixed on the cylindrical part of the housing 1.

The length of the tapering part 2 of the body is at least half the length of its cylindrical part 1. The tapering part of the body is made in the form of a shell of revolution with a central outlet and an arcuate profile of the walls. The profile of the walls of the tapered part is matched with the profile of the walls of the cylindrical part.

The length of the tapering part of the cyclone element is determined by relation (1). The profile of the inner wall of the tapering part is made by an arc of a circle, the radius of which is determined by relations (2), (3), (4).

The one-piece forged body 5 is made from one tubular billet in a swaging die. The body 5 is made of a standard pipe with an inner diameter!), and the exhaust pipe is made of a standard pipe with an outer diameter D _e . The length L _e of the tapered part excludes the effect of discrete sizes of standard pipes on the efficiency of gas purification.

The tapering part of the cyclone element is made with an annular step 9 around the central outlet.

The cyclone element of the multicyclone operates as follows.

The gas to be purified enters through the inlets 8 of two semi-volutes of the guide vane 4 and is directed into the cylindrical part 2 of the housing 1 by two swirling flows.

In the elongated cylindrical part of the housing, the layers of the deposited liquid slide into the tapered part outside the low pressure zone. The resistance force of the swirling gas flow carries the dust particle along a downward trajectory in the form of a cylindrical spiral. Centrifugal force directs dust and liquid particles to the cyclone wall. Dust and liquid particles are concentrated in the near-wall layer of the gas flow. The force of tangential impacts against the cylindrical wall is not enough for particles to slip into the ascending gas flow.

In the short tapering part 3 of the body 1, the direction of the gas flow changes - the flow becomes ascending. The annular stage 9 increases the cross-sectional area of the gas flow, which leads to a local drop in the velocity of the near-wall layer and the radial component of the flow resistance force. The drop in velocity of the near-wall layer already saturated with dust and liquid prevents particles from slipping into the ascending flow of purified gas. The axial component of the downward flow resistance force, centrifugal forces, inertial and gravitational forces press the particles losing speed to the surface of the stage and divert them into the central hole.

EFFECT: invention makes it possible to produce cyclone elements from standard pipes and sheet material using high-performance stamping processes, programmable laser cutting and bending equipment.

The product differs from analogues in its lower weight, lower material consumption, lower labor intensity of production and better efficiency of gas purification.

The production of the proposed cyclone element is implemented in a metalworking plant.

The industrial applicability of the invention is confirmed by testing a prototype multicyclone with a set of proposed cyclone elements.

Claims (12)

1. The cyclone element of the multicyclone includes a body with cylindrical and tapering parts, a guide vane and an exhaust pipe, the length of the tapering part of the body is at least half the length of the cylindrical part, the tapering part of the body is made in the form of a shell of revolution with an arcuate wall profile and a central outlet , the profile of the walls of the tapering part mates with the profile of the walls of the cylindrical part, the guide vane is made in the form of two semi-volutes, the inlets of which are parallel to the axis of the exhaust pipe and directed in opposite directions, the guide vane covers the exhaust pipe and is fixed on the cylindrical part of the housing, characterized in that the length of the tapering part of the housing is related to the parameters of the gas flow being cleaned, the inner diameter of the cylindrical part of the housing and the outer diameter of the exhaust pipe by the ratio

where "*" is the index of linear dimensions, expressed in fractions of the inner diameter of the cylindrical part of the body,

- the length of the tapering part of the body;

- outer diameter of the exhaust pipe; d and d ^* - dust particle diameter in mm and fractions of the inner diameter of the cylindrical part of the housing; μ - dynamic viscosity of gas, Pa⋅s; ρ is the density of dust particles, kg/m ³ ; u _t is the tangential velocity of a dust particle, taken equal to the gas flow velocity at the inlet to the cylindrical part of the housing, m/s. 2. The cyclone element of the multicyclone according to claim 1, characterized in that the profile of the inner wall of the tapering part of the body is made by an arc of a circle, the radius of which is determined by the ratio

where

- radius of the profile circle arc; α - the angle of the beginning of the rolling of the separated fluid particles under its own weight. 3. The cyclone element of the multicyclone according to claim 2, characterized in that the body of the multicyclone is made integrally stamped, and the profile of the inner wall of the tapering part of the body is made by an arc of a circle, the radius of which is essentially determined by the ratio

at

4. The cyclone element of the multicyclone according to one of paragraphs. 1-3, characterized in that the tapering part of the body is made with an annular step around the central hole. 5. The cyclone element of the multicyclone according to one of paragraphs. 1-4, characterized in that the half-volutes of the guide vane are made in the form of curved cylindrical shells fixed between two oval flanges, the cylindrical shells and flanges are made of sheet material and are connected by welds.

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