RU2456224C1 - Screw feeder - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: screw feeder comprises a body and a screw, lined by the material permeable to liquids and gases to form cavities communicated with a source of working body, and the transition node between the feeder and transport route, which is lined inside by the material permeable to gas and liquid to form a cavity communicated with the source of working body. Discharge end of the shaft leans on the outboard bearing.

EFFECT: provision of laminar regime of motion of the mixture along the pipe, removal of radial runout of the shaft.

3 dwg

Description

The invention is intended for the transportation of dust and gas and solid-liquid mixtures in the mining industry, industrial materials, chemical and other industries that produce or process the above products.

Known screw pumps (BH), for example, in the pneumatic conveying of cement and other fine products, containing a screw, a screw drive, a source of working fluid (air), a shut-off valve and a mixing chamber (for example, a pneumatic screw pump TA-14B LLC Stroitelnye Mashiny LLC, St. Petersburg).

The disadvantages of VN are the significant axial amplification of the screw due to air pressure in the mixing chamber, the intensive wear of the screw and the housing due to the plug from the product and centrifugal runout of the shaft end.

Closest to the claimed solution adopted for the prototype is a screw feeder (SU No. 1102751 A, application 3503655 / 29-11 of 10/18/1982, bull. No. 20 of 07/15/1984, author M. Pokushalov) containing a screw with a hollow shaft and with a double working blade, the blade in contact with the product being moved is made of a material that is permeable to gases and liquids, and the cavity between the blades is connected to the source of the working fluid under pressure through openings in the wall of the hollow shaft.

The disadvantages of the prototype:

1. The lack of a node connecting the feeder to the transport highway, which does not provide, in principle, and even more optimal, the modes of loading the highway and the movement of the mixture through it.

2. The lack of support for the discharge end of the feeder shaft, which determines its radial runout and the consequences caused by this (wear of the blades of the lining of the feeder, reduction of hydraulic efficiency).

The invention is directed to connecting the feeder to the line with the provision of coaxial movement of solid and gas particles (laminar flow) and to reduce friction losses at the exit of solid particles from the feeder to the line.

This goal is achieved in that the screw feeder, comprising a housing and a screw, lined on the working side with material that is permeable to gases and liquids (working fluid), with the formation of cavities connected to the source of the working fluid, is characterized in that it contains a transition node between the feeder and transport line, consisting of a solid outer housing and placed inside it with a gap that ensures the formation of a cavity, a sleeve made of a material permeable to liquids and gases, the ends of the body and bushings they are sealed and the cavity formed between them is in communication with the source of the working fluid, and between the ends of the feeder housing and the housing of the adapter assembly there is a suspension bearing consisting of a housing, racks, hub and sleeve made of a material permeable to liquids and gases, mounted on the shaft with the formation of a cavity between the sleeve and the shaft, sealed at the ends of the sleeve with the shaft and communicated through an opening in the wall of the shaft with an internal cavity of the shaft, the end of which is placed inside the transitional unit to ensure normal , in relation to the outer surface of the inner sleeve of the adapter, the gap between the outer diameter of the shaft end and the outer surface of the inner sleeve of the adapter, the size of which is determined empirically for the specific operating conditions of the feeder, and the cases of the feeder, outboard bearing and adapter are connected tightly dismountable by one of known methods.

The differences of the claimed device from analogue and prototype:

1. The feeder is connected to the transport line by a transitional unit, consisting of a durable outer case and placed inside it with a gap providing the formation of a cavity, a sleeve, of a material permeable to liquids and gases, the ends of the case and the sleeve are sealed, and the cavity formed between them is in communication with the source working fluid.

2. The feeder comprises a hanging bearing located between the ends of the feeder housing and the adapter assembly, consisting of a housing, racks, hub and sleeve made of a liquid and gas permeable material, mounted on the shaft to form a cavity between the sleeve and the shaft, sealed at the ends of the sleeve with the shaft and communicated through an opening in the wall of the shaft with the internal cavity of the shaft.

3. The end of the auger shaft is placed inside the transitional unit, ensuring a normal gap with respect to the outer surface of the inner sleeve of the transitional unit of the shaft between the outer diameter of the shaft end and the outer surface of the internal sleeve of the transitional unit, the size of which is determined empirically for the specific operating conditions of the feeder.

The above differences provide the following advantages of the claimed device in relation to the analogue and prototype:

1. The use of the proposed transitional node allows you to: a) prevent the accumulation of the product at the loading point of the transport highway; b) create a laminar mode of motion of the mixture of solid product with the working fluid in the transport highway.

2. The claimed position of the end of the shaft of the screw relative to the transition node provides a seal of the product flow when it enters the flow of the working fluid, thereby reducing the likelihood of movement of the working fluid in countercurrent through the feeder.

3. The use of an outboard bearing of the claimed design provides: a) a decrease in the amplitude of the beats of the end of the screw shaft; b) reducing the gap between the auger blade and the inner surface of the feeder sleeve; c) increasing the hydraulic efficiency of the feeder; g) reducing the size and weight of the feeder.

4. The use of a bearing of the claimed design provides: a) a decrease in the coefficient of friction in the axle; b) a decrease in the rate of wear of the friction pair elements and an increase in the overhaul period of the assembly; c) prevention of contamination of the bearing friction zone with the moved products.

The combined effect of all the differences provides a new technical and economic super-effect and gives reason to consider the inventive screw feeder invention.

Screw feeder device

The screw feeder is shown in FIG. 1 (general view), in FIG. 2 (section along A-A), FIG. 3 (outboard bearing) and consists of the following main components and parts: screw 1, blade 2, longitudinal discontinuous protrusion 3 on the blade 2. Part 4 of the blade 2 is made of a liquid and gas permeable material, drilling 5 communicates the cavity of the blade 2 with the hollow shaft 6 of the screw 1. The device also includes a housing 7, a longitudinal discontinuous protrusion 8 on the inner surface 7, on which the sleeve 9 rests made of liquid and gas permeable material, fitting 10 for supplying ochego body (air, liquid) into the cavity between the sleeve 9 and the housing 7, the seal 11 between the housing 7 and the sleeve 9.

The ratio of the distance h between adjacent protrusions 8 of the housing 7 is equal to the distance B between adjacent protrusions 3 of the blade 2, and its ratio to the thickness of the permeable material is selected no more than ten from the condition of preventing deflection of the permeable material.

The transition node between the feeder and the transport line consists of an external solid-weight housing 12, the inner surface of which has a relief shape, and an inner sleeve 13 of material permeable to liquids and gases, such as cermets, the ends of the housing 12 and the sleeve 13, are sealed, for example, with epoxy resin , and the cavity between them is connected by a pipe 14 with a source of a working fluid (not shown), and the relief, for example, pin protrusions on the inner surface of the housing 12, provides mechanical support for the sleeve 13 and the spread of the working fluid in the cavity between the housing 12 and the sleeve 13. The outboard bearing consists of a housing 15, uprights 16, a hub 17, a sleeve 18 made of a liquid and gas permeable material, such as cermet, fixed, for example, by a tight fit with glue over the local recess shaft 6 with the formation of a gap between the inner surface of the sleeve 18 and the surface of the shaft 6 with its inner cavity. On the end of the shaft 6 are movably fixed, for example, on the thread, the sleeve 19 and the fixing position of the sleeve 19 of the sleeve 20.

The end parts of the housing of the feeder 7, the housing of the transition assembly 12 and the housing of the bearing 15 are made, for example, in the form of flanges with holes that ensure their tight connection to the assembly, for example, by means of a threaded fastener 21. The end of the transition assembly is connected to the transport highway 22.

Screw feeder operation

Preliminarily, on the basis of experiments, the optimal position of the sleeve 20 relative to the outer surface of the inner sleeve 13 is determined. In the absence of a working fluid (P = 0), a feeder drive (not shown) is turned on until the internal product of the transitional unit is filled with the transported product, and then the supply of the working body in P ₂ . The product supplied by the screw 6 into the annular plane between the end of the sleeve 20 and the sleeve 13, is picked up by the working fluid and enters the transport line 22. When the transportation process is completed, the product is stopped flowing into the housing 7, the feeder loading window (not shown) is sealed and, after stripping, the transport the main line, the supply of the working fluid to the cavity of the auger shaft and to the transition node is stopped.

Claims (1)

A screw feeder, comprising a housing and a screw, lined on the working side with material permeable to gases and liquids (working fluid), with the formation of cavities connected to the source of the working fluid, characterized in that it contains a transition node between the feeder and the transport line, consisting of a durable the outer casing and placed inside it with a gap that ensures the formation of a cavity, a sleeve made of a material permeable to liquids and gases, and between the ends of the feeder housing and the transition assembly housing and a suspension bearing is placed, consisting of a housing, racks, hub and sleeve made of a liquid and gas permeable material, mounted on a shaft to form a cavity between the sleeve and the shaft, sealed at the ends of the sleeve with the shaft and communicated through an opening in the shaft wall with an internal a cavity of the shaft, the end of which is located inside the transitional unit, ensuring a normal gap with respect to the outer surface of the inner sleeve of the transitional transitional unit between the outer diameter of the shaft end and the outer surface of the inside the lower bushings of the adapter assembly, the size of which is determined empirically for the specific operating conditions of the feeder, and the feeder housing, the outboard bearing and the adapter assembly are connected firmly and separably using one of the known methods.

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