RU2486124C2 - Vertical screw conveyor - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: vertical screw conveyor comprises vertical shaft 1 articulated with drive and carrying helical coils 2 to rotate inside casing 3, loading and unloading devices. Said casing is composed of arched elements 4 welded together in lengthwise direction that flex outward from the shaft. Inner edges of said elements are arranged in circle arc with radius R₀ exceeding that of helical coils with minimum clearance 5. Magnitude of radius R of curvature of aforesaid arched casing elements is defined from relationships: $$R=\mathrm{0,25}{b}^2-\mathrm{0,5}\left[r+R_0-{\left(R_0^2-\mathrm{0,25}{b}^2\right)}^{\mathrm{0,5}}\right];$$

b = 2R₀ sin (π/n), where b is arched element width, m; r is maximum distance between circle of radius R₀ and inner surface of arched surfaces, m; n is quantity of said arched elements. Magnitude r is set depending upon the size of conveyed lumps not to exceed 1.5-2 transverse sizes of lumps.

EFFECT: higher efficiency, reduced power consumption.

4 dwg

Description

The invention relates to continuous transport vehicles for transporting small bulk cargoes, in particular to vertical screw conveyors, and can be used in processing plants of mining enterprises and enterprises of other industries.

Known for the prototype is a vertical screw conveyor containing a vertical shaft kinematically connected to the drive with continuous screw turns fixed to it with the possibility of rotation in a cylindrical casing, loading and unloading devices (Spivakovsky A.O., Dyachkov V.K. Transporting machines, M ., Engineering, 1968, p. 361-363, Fig. 257a, b).

A disadvantage of the known conveyor is the significant energy consumption of transporting bulk goods due to the increased rotational speed of the shaft with a helical surface to create the necessary centrifugal force of the transported cargo, pressed against the inner surface of the cylindrical casing in order to ensure transportation of the load up, which in turn is ensured when a condition for the excess of the friction force of the load on the casing over the friction force of the load on the helical surface of the drive shaft.

The technical result of the invention is to reduce the energy intensity of transportation of bulk cargo due to the possibility of reducing the frequency of rotation of the shaft with helical turns.

The technical result is achieved by the fact that in a vertical screw conveyor containing a vertical shaft kinematically connected to the drive with screw coils mounted on it with the possibility of rotation inside the casing, loading and unloading devices, the casing is made in the form of longitudinally interconnected by welding arcuate in transverse cross-section of elements with their deflection outward from the shaft, the inner edges of which are located on an arc of a circle with a radius R ₀ exceeding with a minimum clearance the radius of the screw coils c, wherein the radius R of curvature of the casing of the arcuate elements is taken from the relations

; b=2R₀sin(π/n), $$R=0.25b^2-0.5\left[r+R_0-{\left(R_0^2-0.25b^2\right)}^{0.5}\right]$$

; b = 2R ₀ sin (π / n),

where b is the width of the arcuate elements, m; r is the maximum distance between a circle of radius R ₀ and the inner surface of the arcuate elements, m; n is the number of arcuate elements forming the casing. The value of r is set depending on the size of the pieces of transported cargo and is taken no more than 1.5 ÷ 2 transverse dimensions of the pieces.

The vertical conveyor is presented in figure 1 is a side view of its middle part, in figure 2 is a cross section, in figure 3 is a cross section when covering the surface of the screw coils with antifriction material, in figure 4 is a longitudinal section of the middle part of the conveyor when performing vertical shaft in the form of a pipe.

The vertical screw conveyor comprises a vertical shaft 1 kinematically connected with the drive (not shown) with screw coils 2 mounted thereon with the possibility of rotation inside the casing 3, loading and unloading devices (not shown). The casing 3 (Fig. 1) is made (Fig. 2) in the form of elements 4 longitudinally interconnected by welding arched in cross section with their deflection outward from the shaft 1, the inner edges of which are located along a circular arc with a radius of R ₀ (m) exceeding with a minimum clearance 5 the radius of the screw turns 2. Moreover, the radius R (m) of the curvature of the casing of the arcuate elements 4 is taken from the relations

; b=2R₀sin(π/n), $$R=0.25b^2-0.5\left[r+R_0-{\left(R_0^2-0.25b^2\right)}^{0.5}\right]$$

; b = 2R ₀ sin (π / n),

where b is the width of the arcuate elements 4, m; r is the maximum distance between a circle of radius R ₀ and the inner surface of the arcuate elements 4, m; n is the number of arcuate elements 4 forming the casing 3. The value of r is set depending on the size of the pieces of the transported cargo 6 and is taken no more than 1.5 ÷ 2 transverse sizes of the pieces.

The surface of the screw turns 2, as well as the known horizontal and inclined screw conveyors, can be covered with a layer of antifriction material 7 with respect to the transported cargo 6 (Fig.3). In addition, as with the known screw conveyors, the vertical shaft 1 can be made in the form of a pipe 8 connected to a source of compressed air (not shown), and the surface of the pipe 8 is made with holes 9 along the entire length corresponding to the height of the transported cargo 6 (figure 4).

Vertical screw conveyor operates as follows. When the shaft 1 is rotated with screw coils 2 mounted on it, the transported load 6, located inside the arcuate elements 4 of the casing 3, is shifted upward without rotation in the horizontal plane at a shaft 1 rotational speed lower than that of the prototype conveyor. Moreover, due to the increased cross-sectional area of the load 6 with its placement in the segmented zones of the arcuate elements 4, the conveyor productivity can be increased. The condition for the transportation of cargo 6, which consists in the excess of the friction force of the cargo 6 on the casing 3 over the friction force of the cargo 6 on the working surface of the screw turns 2, is ensured by reducing the coefficient of friction of the load 6 on the screw turns 2, which are coated with a layer of antifriction material 7. This the condition is also satisfied by reducing the coefficient of friction of the load 6 on the surface of the screw turns 2, but by increasing the mobility of the pieces of transported cargo 6 in the area of their contact with the working surface of the screw turns 2 p One effect of penetrating through the holes 9 in the pipe 8, from which the shaft 1 is made, flows of compressed air. In addition, in this case, the friction force of the load 6 on the inner surface of the casing 3 is further increased due to the displacement of the particles of the load 6 towards the casing 3 under the action of jets of compressed air emerging from the openings 9 of the shaft 1, which is made in the form of a pipe 8.

Distinctive features of the invention provide a reduction in energy consumption of transportation by reducing the rotational speed of the shaft with helical turns, as well as increasing productivity by increasing the cross-sectional area of the cargo flow.

Claims (1)

A vertical screw conveyor comprising a vertical shaft kinematically connected to the drive with screw turns fixed on it with the possibility of rotation inside the casing, a loading and unloading device, characterized in that the casing is made in the form of elements longitudinally interconnected by welding arc-shaped in cross section with their deflection outward from the shaft, the inner edges of which are located on an arc of a circle with a radius R ₀ exceeding with a minimum clearance the radius of the screw turns, while the value of mustache R curvature of the casing of the arcuate elements is taken from the ratios:
$$R=0.25b^2-0.5\left[r+R_0-{\left(R_0^2-0.25b^2\right)}^{0.5}\right]$$

; b = 2R ₀ sin (π / n),
where b is the width of the arcuate elements, m; r is the maximum distance between a circle of radius R ₀ and the inner surface of the arcuate elements, m; n is the number of arcuate elements forming the casing, while the value of r is set depending on the size of the pieces of transported cargo and is taken no more than 1.5 ÷ 2 transverse dimensions of the pieces.

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