RU2027525C1 - Cyclon-type trap - Google Patents

Abstract

FIELD: textile industry; extraction of foreign particles from air-cotton mix being conveyed. SUBSTANCE: cyclon-type trap has cylindrical housing 1, branch pipe 2 for feeding flow to be cleaned and axial pipe 4 for discharging cleaned flow. Ring-shaped nozzle 5 opposes concentrically entry opening of pipe 4 and is intended to supply auxiliary air flow. Size of nozzle is selected with the use of special formulas. EFFECT: improved quality of cleaning. 1 dwg

Description

 The invention relates to the textile industry, in particular to centrifugal devices in a pneumatic transport system, and is intended to separate foreign bodies from the transported air-cotton mixture.

 Typical cyclones for cleaning the working medium are known, which are a cone with a short cylindrical part having an inlet (supply) pipe to which the working medium is supplied. The cyclone body is equipped with an outlet pipe and a hopper trap. The supply pipe is located so that the working medium is introduced tangentially into the cyclone and rotates in it with the formation of external and internal flows. Under the action of centrifugal forces, foreign bodies are brought to the cyclone wall and enter the hopper, while the purified mixture moves in the central part of the cyclone, forming an internal vortex flow [1].

 The disadvantages of this device are the large aerosol resistance, low separation efficiency and the lack of stabilization of the cyclone. The large aerosol resistance is due to the multiple rotation of the flow and the considerable height of the device. Low cleaning efficiency is associated with the impossibility of creating significant centrifugal forces without a significant increase in the resistance of the device and its size. The stabilization of the cyclone is violated due to clogging of the volumes of the cyclone body with an air-cotton mixture.

 A device of a vortex separator is also known, which, in order to increase the degree of separation, is equipped with an additional nozzle for supplying gas to the cyclone chamber. An additional pipe is installed tangentially in the housing above the inlet pipe [2].

 The disadvantages of this device include the high aerosol resistance of the cyclone chamber, which is explained by the high level of swirling flow, and the low stabilization of the cyclone due to the possibility of clogging with the air-cotton mixture of the working paths of the device.

 The aim of the invention is to stabilize the operation of the device by eliminating clogging with the air-cotton mixture of the outlet pipe and reducing the drag of the trap.

и r_н < r_вых, где r_вых - радиус трубы вывода; r_вх - радиус патрубка ввода; r_в - средний радиус сопла; r_н - наружный радиус сопла; φ - коэффициент заполнения, определяемый из уравнения

= (1-φ)

, где R_ц - радиус корпуса.This goal is achieved in that the input of the auxiliary air flow is made in the form of an annular nozzle directed towards the inlet of the outlet pipe concentrically to it. In this case, the nozzle dimensions are determined by the formula r _in = r

and r _n <r _o , where r _o is the radius of the outlet pipe; r _I - the radius of the input pipe; r _in - the average radius of the nozzle; r _n is the outer radius of the nozzle; φ - duty cycle, determined from the equation

= (1-φ)

where R _C is the radius of the housing.

 The proposed technical solution meets the criterion of "significant novelty."

 The drawing shows a schematic diagram of a cyclone trap.

 The cyclone trap consists of a cylindrical body 1 provided with an inlet tangential branch pipe 2, and a collector 3 of separated impurities. An axial tube 4 of the output of the cleaned stream and an annular nozzle 5 are placed in the housing.

 The cyclone trap works as follows.

, где φ - коэффициент заполнения, определяемый из уравнения

= (1-φ)

, где R_ц, r_вх, r_вых - радиусы цилиндрического корпуса, патрубка ввода очищаемого потока, трубы вывода очищенного потока соответственно. На радиусе r_в величина окружной составляющей скорости U имеет наибольшее значение, которое определяется уровнем закрутки потока и определяет аэросопротивление циклонной ловушки, так как большая часть располагаемой энергии потока расходуется на создание окружной скорости.The working medium (air-cotton mixture) enters the cyclone chamber of the housing 1 of the trap along the tangential pipe 3 input. The tangential inlet of the working medium provides a flow swirl in which two flow regions are poured: the potential flow region, where the condition of constant circulation is met ur = const, u is the peripheral velocity component at the current radius r, and the region of the axial flow of the working medium, where it rotates as a solid body i.e. u = Wr, where w is the angular velocity of rotation. The boundary between these regions runs along a circle of radius r _in = r

where φ is the duty cycle determined from the equation

= (1-φ)

where R _c , r _in , r _out - the radii of the cylindrical body, the input pipe of the cleaned stream, the output pipe of the cleaned stream, respectively. At a radius r _{in the} value of the peripheral component of the velocity U has the greatest value, which is determined by the level of swirling the flow and determines the drag of the cyclone trap, since most of the available flow energy is spent on creating the peripheral speed.

Since the moment of momentum (swirl) created due to the tangential supply of the working medium remains approximately constant during the movement of the working medium, with decreasing r (narrowing of the flow), the peripheral velocity component increases and centrifugal forces arise that press the flow against the wall. Under the action of centrifugal forces, foreign bodies having a higher density than the air-cotton mixture are brought to the cyclone wall and fall into the collection of 3 separated impurities. The cleaned cotton-air mixture rises along the outer surface of the axial outlet pipe 4 and is entrained at its slice by an auxiliary stream of air flowing from the annular nozzle 5. The supply of an auxiliary air stream from the annular nozzle along the circumference r _in , firstly, reduces the maximum level of the peripheral velocity component due to the message to the swirling flow of additional movement parallel to the axis of the pipe and the output, and secondly, it creates an ejection effect due to the translational axial movement of air. The auxiliary air stream destroys the inner vortex and pushes the air-cotton mixture, reducing the likelihood of clogging of the outlet pipe with the working mixture. In order to increase the efficiency of the trap as a jet pump, the outer radius of the annular nozzle r _{n is} made smaller than the radius of the outlet pipe r _o , i.e. r _n <r _o

=0,0635 м. Поскольку расход рабочего тела (воздушно-хлопковой смеси) составляет 1,5 м³/с, а его скорость 25 м/с, то выбирая расход вспомогательного воздуха 0,15 м³/с и скорость истечения вспомогательного потока воздуха 35 м/с, из уравнения расхода можно найти толщину кольцевого сопла, равную 0,01 м. По известному среднему радиусу сопла и толщине определяется наружный радиус сопла r_н = =0,0685 м, который обеспечивает выполнение неравенства r_н < r_вых.An example of a specific implementation of the proposed device can be a cyclone trap installed on the pneumatic conveying line of the air-cotton mixture having a radius of 0.1 m. In this case, the radii of the inlet tangential branch pipe 2 and the axial outlet pipe 4 are equal to the radius of the pneumatic conveying line, i.e. r _in = r _out = 0.1 m. From the condition of ensuring the swirling of the flow by means of a tangential supply of the working fluid into the swirling chamber without a significant increase in drag, the radius of the cylindrical body R _c = 0.225 m is assigned. For the selected sizes of the elements of the cyclone trap from equation (1) is determined the value of the fill factor φ = 0.6, and then the average radius of the nozzle r _in = 0.1

= 0.0635 m. Since the flow rate of the working fluid (air-cotton mixture) is 1.5 m ³ / s and its speed is 25 m / s, choosing the flow rate of auxiliary air 0.15 m ³ / s and the flow rate of the auxiliary flow air 35 m / s, from the flow equation you can find the thickness of the annular nozzle equal to 0.01 m. From the known average radius of the nozzle and the thickness, the outer radius of the nozzle r _n = 0.0685 m is determined, which ensures the inequality r _n <r _o .

The proposed device has compared with the known, selected as a prototype, a number of advantages:
provides stabilization of the cyclone trap due to the creation of an ejecting effect and an additional high-speed pressure at the inlet of the axial pipe output of the cleaned stream;
reduces the aerosol resistance of the cyclone trap due to a decrease in the peripheral velocity component, destruction of the inner vortex and additional energy flow to the air-cotton mixture flow;
reduces the air resistance of the section of the pneumatic transport line located downstream of the trap, and improves the working conditions of the aggregates of the transport line due to the destruction of the vortex structure of the stream at the exit of the trap.

Claims (1)

A CYLON TRAP containing a cylindrical body, a nozzle for introducing a stream to be cleaned, an axial pipe for withdrawing a purified stream, an inlet of an auxiliary air stream, a collection of separated impurities, characterized in that the inlet of the auxiliary stream is made in the form of an annular nozzle directed toward the inlet of the outlet pipe, concentrically to it while the nozzle dimensions are determined by the formulas

r _n <r _{s in x,}
where r _{in s x} is the radius of the outlet pipe;
r _{in x} is the radius of the input pipe;
r _in - the average radius of the nozzle;
r _n is the outer radius of the nozzle;
φ - duty cycle, determined from the equation

where R _c is the radius of the housing.