SU1204516A1 - Jet pump for pneumatic transportation of loose material - Google Patents

Description

The invention relates to the pneumatic transport of bulk material and can be used for pumps moving gas mixtures containing solid particulate dust-like materials, for example, cement.

The purpose of the invention is to increase productivity and reliability by reducing stagnant zones.

FIG. 1 shows schematically a jet pump, a general view; in fig. 2 is a section A-A in FIG. one; in fig. 3 is a graphical interpretation of characteristic zones in the pump chamber of FIG. 1 with a distribution of velocities and pressures; in fig. 4 is a diagram of the gas flows in the annular gap of FIG. 1-, FIG. 5 is a graphical interpretation of the distribution of velocities and pressures in the annular gap of FIG. four.

The jet pump contains a chamber 1 with a loading opening 2, an integrated nozzle 3 and an airfoil 4, a mixing chamber consisting of a tapering part (confusor) 5, a cylindrical section f and an expanding part (diffuser) 7.

Inside the chamber 1 on the side wall around the nozzle 3 installed concentric: nozzle 8, the inner surface of which is made in the form of an aerodynamic profile. An additional nozzle 9 is directed into the annular space between the nozzle 3 and the nozzle 8. Tangentially directed to the inner surface of the annular nozzle 8. Through channels 10 are made in the body of the annular nozzle 8, and the axis 11 of the channels 10 is at an acute angle and to the axis of the outlet 12, The openings of the channels 10 with their expanding part 13 extend into the annular gap between the nozzle 3 and the nozzle 8 in the zone of its smallest section.

The device works as follows.

The bulk material is supplied to the chamber 1. of the jet pump through the charging opening 2. The ejecting gas is supplied under pressure to the nozzles 3 and 9; aerating gas - to the aero bottom 4.

FIG. 3 and 5, the characteristic lines and zones of the operating pump are shown: the gas flow line 14 from the nozzle 3; gas flow line 15 from annular packing 8 (circulation zone boundary); line 16 zero speeds in chamber 1; a constant mass flow zone 17 limited by the boundary of the circulation zone 15 and the walls of the pump; vortex zone 18 (hatched), limited by current line 15 and line 16 zero speeds; zone 19 with reverse gas flow; line 20 plot of static pressure along the axis of the pump; line 22 diagrams of the total pressure along the pump axis; line 23 of velocity diagrams in the annular gap between nozzle 8 and nozzle 3 at the most characteristic points; line 24 epures of average speeds along the annular gap between the nozzle 8 and the nozzle 3; Line 25 of plot of average pressures along the annular gap between nozzle 8 and nozzle 3. Expanding in nozzle 3, the flow of ejecting gas Wi acquires a high velocity of 5 Vi. The ejecting gas W2, also exiting the nozzle 9 at a sufficiently high velocity V2, is twisted in the annular space between the nozzle 8 and the nozzle 3, rushing along the spot 3 to the exit from the annular space.

 - Due to the aerodynamic effect of the profile of the inner surface of the nozzle 8, the initial velocity of the gas flow Ug, as the annular gap between the nozzle 8 and the nozzle 3 narrows, ages to the ultrasonic value. The gas flow W2, the passage at high speed through the annular gap, due to the discharge on the inner surface of the nozzle 8, produces a suction of the gas flow Wa through the through channels 0 from the outside of the nozzle 8 from the zone

0 and passive gas chamber 1, capturing suspended particles of the material. The interaction of gas flows W2 and Shz leads to a general compaction of the flow in a narrow place of the annular gap and an even greater increase in the flow rate to Y4. General average

 The flow pressures in the annular gap between the nozzle 8 and the nozzle 3 tend to decrease with a characteristic pressure drop in the zone of the through channels 10. The average velocity Vcp of the flow in the annular gap increases with a sharp increase in the speed AV in the zone of through channels 10. At the exit from the annular gap the gas stream is mixed with the gas stream Wi exiting from the nozzle 3. In the mixing zone of chamber 1, the jet of active gas interacts with the feed material, forming an air-material mixture.

In view of the presence of the nozzle 8 and the gas leaking through the channels 10, the circulation boundary 16 and the vortex zone 17 are moved away from the nozzle 3,

occupies almost the entire volume of the camera 1.

The zone 19 with the reverse movement of the gas is reduced and practically remains only in the zone of the loading opening 2. The constant flow zone 17 is expanded due to the nozzle 8. In addition, the material is continuously supplied from the vortex zone 18 and the zone 19 with reverse current through the channels 10 to zone 17 of constant mass flow. The residence time of a part of the material in the passive gas zone is shortened, which reduces the deposition and adhesion of the material to the walls of the chamber 1 and the air floor 4.

In combination with the rotational movement (around the nozzle 3) of the gas flow in the annular gap, these features lead to sharp phase oscillations inside the fast-moving gas flow in zone 17. Kinematic and, as a result, dynamic effects (especially sharp phase

The oscillations) of the compressed gas flow ensure the complete mixing of the air mixture. In the mixing zone, the gas flow accelerates the resulting air mixture and entrains it into the diffuser 5, where the resulting air mixture is compressed. Then, in the cylindrical part 6 of the chamber, further mixing of the flows and equalization of the velocity fields occurs, and in the diffuser 7 - acceleration of the aero-material mixture to the transport speed.

13

Passive gas zone (wicreo-zone and gradient flow zone)

20

Mixing zone

Zone of constant mass flow

Zone 8i (section V

3

  I 0

Wxx /

Compiled by E. Guchkova

Editor L. Veselovska Tehred I. VeresKorrektor S. Cherni

Order 8478/20 Circulation 833 Subscription

VNIIPI USSR State Committee

inventions and discoveries

113035, Moscow, Zh-35, Raushsk nab. 4/5

Branch PPP "Patent, Uzhgorod, st. Project, 4

Claims (2)

1. JET PUMP FOR PNEUMATIC TRANSPORTATION OF BULK MATERIAL, containing a chamber with loading and outlet openings made respectively in its upper and lateral walls, an aerial plate installed and a nozzle placed above it, a transport wire connected to the chamber, and a compressed air source in communication with the nozzle and the aerodrome, the fact that, in order to increase productivity and reliability by reducing stagnant zones, it is equipped with an annular nozzle mounted concentrically to the nozzle mounted on its side the chamber wall and made with an inner surface in the form of an aerodynamic profile with the formation of an annular gap expanding towards the side wall of the chamber, with an opening in the zone of the largest gap and through channels located at the end of the annular nozzle remote from the side wall of the chamber and inclined at an acute angle to the axis nozzles toward the outlet of the chamber, and an additional nozzle mounted tangentially to the outer surface of the first nozzle in said hole of the annular nozzle and communicated with compressed air meter. 2. The pump according to π. 1, characterized in that the through channels are made expanding towards the outlet of the camera. FIG. 1