RU2191640C1 - Device for separation of hard loose materials by dry method - Google Patents

Abstract

FIELD: technology of separation of hard loose materials by dry method, mainly, broken sheet glass; applicable in technology of grinding of materials in hammer crushers for production of powders of definite granulometric composition. SUBSTANCE: device includes located along symmetry longitudinal axis a flow shaper in the form of trough installed at an angle to horizon ensuring material sliding over its surface and conveyor belt conjugated with trough and installed for hoisting. Trough working surface is formed of central and side parts. Central part is triangular in shape and located with its base facing container unloading hatch with width B not less than that of unloading hatch and with vertex conjugated with straight section of conveyor belt. Angle α at triangle vertex is found from condition 20^°<α<80^°. Trough side parts are in the form of channels adjacent to triangle sides and convergent at triangle vertex and made with shelf downward increasing toward conveyor belt and with total width not exceeding the working zone conveyor belt, and angle β of rise of conveyor belt is found from relationship T $\genfrac{}{}{0ex}{}{\text{°}}{\text{1}}$ <β<T $\genfrac{}{}{0ex}{}{\text{°}}{\text{2}}$ , where T₁ is an angle of friction of separated material with separated material; T₂ is an angle of friction of separated material with material of conveyor belt. Channel bottoms are inclined toward side of shelf face through an angle δ determined from relationship δ = arctg(tgα/2×tgβ) in this case, channel depth on side opposite to shelf is not smaller than shelf depth whose value is not less than 0.6 of maximum size of fraction. EFFECT: highly efficient and economical separation of flat loose materials, mainly, broken sheet glass, increased reliability of separation of lying bulk material. 4 dwg

Description

 The invention relates to a technology for the separation of dry bulk solid materials stored in bulk, mainly flat glass waste (cullet), and can be used in the technology of grinding material in hammer crushers to obtain powders of a certain particle size distribution, in particular, for the production of glass microspheres.

 The use of cullet is an important source of saving raw materials. At the same time, the collection, transportation and especially sorting of waste are the most expensive and time-consuming technological stages, which account for up to 75% of the total amount of processing costs.

 To obtain some types of products, mainly colorless window glass is used, the waste of which has a maximum size of several tens of centimeters, is stored and transported in bulk. Subsequent processing, for example, for the production of granules of an ideally spherical shape, involves the preparation of an initial powder ranging in size from 5 to 1000 microns. This is achieved by using hammer crushers in combination with screens and screens.

 Material intended for processing in a hammer mill must have dimensions that do not exceed the width of the neck of the mill, and arrive there in the form of a uniform, monolayer stream, which requires an effective system for the separation of bulk waste.

 A wide range of devices for the separation and transportation of solid bulk materials is known, which are based on various physical principles. One of these is the principle based on different speeds of particles on the surface, due to different coefficients of friction of materials (relative friction).

 For example, "A device for separating spherical solid particles from particles of irregular shape" [US Pat. RF, 1478997, IPC В 07 В 13/00, prior 21.09.82], containing a horizontal rotating table with a concave conical surface and a central hole. At the top of the table, close to the outer contour, there are vertical pipes for feeding material and tangentially oblique scrapers to remove irregularly shaped particles. Particles are separated by the difference in their friction coefficients on the table: round particles at a given rotation speed roll toward the center of the hole, and irregular particles are forcibly removed by scrapers outside the outer contour of the table. Such a device does not allow the separation of flat bulk materials.

 Also known separator for the separation of bulk materials [US Pat. RF, 2017552, IPC В 07 В 13/10, prior. 04/03/91], including several coaxial helical grooves with a slope of the bottoms in the direction of the vertical axis of symmetry. The winding pitch of the screw gutters is made smoothly decreasing from the top to the bottom of the device. The lower the coefficient of friction of the granules, the higher the speed of their sliding along the helical trough and the greater the centrifugal acceleration, and therefore, the farther from the center they are displaced. Separation is based on this principle. Separation in such a device is ineffective and of poor quality, since particles due to mutual friction drag each other in opposite directions, preventing separation. Another significant drawback is the increased dimensions of the device. The device is not suitable for separating flat materials.

The closest in technical essence to the claimed invention is a device for laying out pieces of mineral raw materials [Ed. St. USSR, 1607980, IPC 07 13/16, 15/00, prior. 11.23.87], including a unloading device located along the longitudinal axis of symmetry, a flow shaping device in the form of a vibratory tray installed at an angle to the horizon, which allows the material to slide along its surface, and a conveyor belt that is connected with it and is lifted upward. In this case, the vibration tray is installed at the side of the drum of the conveyor belt so that its bottom is located above the axis of the conveyor drum and below the surface of the conveyor belt. The raw material in the vibratory tray is layered and moves continuously with a stable speed (most likely, the vibratory tray is equipped with means for adjusting the linear velocity of the material). The main disadvantage of this device is the low separation efficiency due to the short length of the separation zone (9.16 cm) at the arc of the drum with an angle equal to 35 ^o , which is less than the average size of the fraction. Moreover, along the length of the arc, the angles of inclination to the horizon are variable and amount to less or more than optimal, as a result of which the separation process is unstable and ineffective, since a piece of material is either not captured at all or 2 layers are captured immediately.

 We have proposed a high-performance, economical separator of solid flat bulk materials, mainly sheet glass breakdown, providing with a high degree of reliability the separation of bulk material by organizing its movement by self-emptying with the gradual transformation of the multilayer flow into a monolayer.

We have achieved such a technical effect when, in a device for the dry separation of solid bulk materials stored in bulk, mainly sheet glass breakdown, including a flow shaper placed along the longitudinal axis of symmetry in the form of a tray installed at an angle to the horizon, allowing the material to slide on its surface, and the conveyor belt attached to it mounted with a lift, it is new that the working surface of the tray is made of central and side parts, the contour of the central h STI has the shape of a triangle arranged base to the discharge hatch of the container, with the width B is not less than the width of the unloading hatch and the top, conjugate with the straight portion of the conveyor belt, the angle α at the apex of the triangle is found from the condition of 20 ^o <α <80 ^o, side parts of the tray are made in the form of gutters adjacent to the sides of the triangle and converging at its apex, made by a step downward, increasing towards the conveyor belt, and with a total width not exceeding the width of the working zone of the conveyor belt, and lifting β conveyor belt is found from the relation T ₁ ^o <β <T ₂ ^o, where T ₁ - the angle of friction material being separated by the separated material, T ₂ - angle of friction material being separated by material of the conveyor belt, the bottom of the troughs are inclined to the side faces ledge to the angle δ, found from the relation δ = arctan (tanα / 2 • tanβ), while the depth of the trench from the side opposite the ledge is not less than the depth of the ledge, the value of which is not less than 0.6 of the maximum size of the fraction.

 The new set of essential features made it possible to implement the technology of dividing the battle flow of sheet glass lying in bulk in a monolayer, providing spontaneous (self-filling) formation of an ordered flow, excluding material adhesion during flow narrowing, with the final separation in a monolayer on a conveyor belt due to relative friction.

 Figure 1 shows a diagram of a technological line for crushing cullet in a hammer mill (side view), where the flow former located along the longitudinal axis of symmetry is a tray consisting of the central part 1, side grooves 2, conveyor belt 3 of conveyor 4, transport container 5 s an unloading hatch 6, placed on a table 7, adjustable in height and inclination, with stops 8, a hammer mill 9 with a receiving neck 10.

AA is the cross section of the tray,
β is the angle to the horizontal horizon of the conveyor belt.

 Arrows indicate the direction of movement of the separated material.

 Figure 2 shows a diagram of the claimed device (top view), where the Central part of the tray 1 in the form of a triangle, side channels 2, conveyor belt 3 of the conveyor 4, transport container 5, unloading hatch 6, table 7, stops 8, crusher 9 with neck 10.

 SS - longitudinal section of the tray.

 B is the width of the base of the triangle, D is the width of the side grooves, S is the width of the conveyor belt, L is the length of the central part of the tray along the material flow.

 α is the angle at the apex of the triangle conjugated with a straight section of the conveyor belt 3.

 Arrows indicate the direction of movement of the separated material.

 In FIG. 3 shows a cross section AA of the tray indicated in FIG. 1, where tray 1, trough 2.

 B is the width of the base of the central part of 1 tray, D is the width of the trough, N is the height of the ledge of the trough at its beginning.

 δ is the angle of inclination of the bottom of the gutter to the edge of the ledge.

 The arrows indicate the direction of movement of the separated material from the central part of the tray into the gutters.

 In FIG. 4 shows a longitudinal section of the CC tray indicated in FIG. 2, where tray 1, trough 2, conveyor belt 3.

H is the height of the step at the beginning of the gutter, H ₁ is the height of the step at the end of the gutter at the conveyor belt.

 The device operates as follows. From the container 5, the separated material is poured in bulk onto an inclined tray, the width of which is not less than the width of the discharge hatch 6 of the container, which ensures the elimination of material losses during loading. The thickness of the layer of material to be separated on the tray can be determined by tilting the container. A significant excess of the angle of inclination of the container relative to the angle of friction of the separated material on the material of which the floor of the container 5 is made leads to an unjustified increase in the thickness of the layer, which in turn leads to an increase in the pressure of the layer on the moving belt 3 of the conveyor 4, leading to an increase in its wear .

 The angle of inclination of the tray to the horizon is selected from the condition of ensuring the sliding of the separated material on the surface, taking into account the coefficient of friction of the separated material on the surface of the tray, i.e. the angle of inclination of the tray is greater than the angle of friction of the material on the tray. Approaches to solving this problem are known. On the tray, the material is in bulk, layered. Due to the implementation of the tray from the central 1 and side 2 parts, the input stream is divided into 3 intermediate streams. Due to the fact that the central part 1 of the tray is made in the shape of a triangle, its side flows are rotated relative to the input to the right and left. The angle α at the apex of the triangle is selected to the extent that provides the length L and tray area necessary for the formation of the flow. For separated materials with a small fraction size, predominantly large angles are selected, for materials with a large fraction size, smaller ones are chosen. At an excessively large angle, oblique falling asleep of the material relative to the axis of symmetry of the conveyor occurs, the friction of the separated material on the walls of the troughs 2 increases, which leads to an undesirable increase in the transverse tilt of the troughs by an angle δ. Too small angle at the top unnecessarily increases the dimensions of the device.

The narrowing of the material flow on the inclined tray is not due to the lateral compression of the flow, in which the adhered sheets are inhibited and self-feeding is not achieved, but due to the flow breaking in the vertical direction at the edges of the narrowing central part of the tray. In this case, individual sheets are disconnected from each other and fall down on the left and right gutters. The experimentally found fall height H, as well as the height of the opposite wall of the gutter, is selected to be at least 0.6 of the maximum size of the fraction of the separated sheet battle, which ensures reliable separation of pieces when the material falls into the gutters. The height H of the ledge down at the side channels is variable along their length: the farther from the loading container, the deeper the ledge, the height of the conveyor belt is H ₁ . This, on the one hand, maintains the optimum height of falling pieces of material with increasing layer thickness at the bottom of the gutter as the material falls down from the center of the tray and the gutters are filled, and on the other hand, it creates the same sliding conditions for the material on the central and side parts of the tray with taking into account the laws of spatial geometry, since the length of the gutters is 1 / cos (α / 2) times longer than the length of the central part of the tray. The difference in height of the ledge at the end and beginning of the gutters is determined by the following relationship:
H ₁ -H = L • sin (α / 2) ([1 / cos (α / 2) -1], where L is the length of the central part of the tray along the material flow.

The lateral grooves 2 are conjugated with a conveyor belt 3 with their lower ends 3. In order to ensure a minimum clearance along the entire length of the mating line of the bottom of the grooves, they are made obliquely to the edge of the ledge, the angle of inclination δ is selected from the relation connecting this angle with the angle α at the apex of the triangle and the angle β of elevation conveyor belt, and is calculated by the formula δ = arctan (tanα / 2 • tanβ). The angle of "skew" of the lower end edge of the trough relative to the longitudinal axis of symmetry, it is advisable to perform equal to 90 ^o - α, which corresponds to the above dependence. In this case, the lower end of the gutter will be rectangular.

 The total width of the grooves in the interface zone with the straight section of the conveyor belt 3 does not exceed the width S of the working zone of the conveyor belt, which in turn corresponds to the width of the neck 10 of the hammer mill 9, and is selected, as a rule, slightly less than the width of the neck of the mill.

 The conveyor belt is mounted upward by an angle β greater than the friction angle of the material to be separated on the material to be separated and less than the angle of friction of the material to be separated on the material of the conveyor belt. This condition ensures the separation of pieces of material in a monolayer, because at any thickness, the lower layer of material is mated to the material of the conveyor belt and therefore transported to the crusher, all upper layers of the material slide back to the base of the conveyor belt. In case of accidental capture in the initial zone of the conveyor belt of two layers of material, the upper layer will inevitably slip during transportation. The efficiency and rationality of the separation principle is based on the fact that separation is carried out only in the lowest layer of a chaotic material, and all the upper pieces of material are not involved in the separation process.

 As a rule, a straight section of the conveyor belt goes under the gutters in order to prevent spilling of material on the floor. The magnitude of the entry of the conveyor belt under the gutters is due to the margin of the straight section of the conveyor belt, corresponding to the range of adjustment of the conveyor length while ensuring the belt tension. To ensure the elimination of losses of small fractions in this zone, the end ends of the gutters are equipped with an elastic apron.

 To eliminate the vibrations of the conveyor belt and change the angle of its inclination, the upper belt along the entire length between the drums is supported by a carrier made of wood.

 The mass productivity (kg / h) of the material supply to the crusher is determined by the mass productivity of the latter, depends on the cross section of the monolayer of material on the tray and is determined by the speed of the conveyor belt. Approaches to finding the speed of conveyor belt are known.

 An example of a specific implementation. At our enterprise, a device for dividing the battle of sheet glass was manufactured according to the invention. After successful testing, the device was included in the technological line for obtaining the initial glass powder of a certain particle size distribution for the production of microspheres.

As a fight for sheet glass, glass production wastes (fraction size up to 300 mm, thickness 4 mm) used in transport containers with a carrying capacity of 3 tons and dimensions of 1.8 x 1.8 x 0.8 (m) (length, width, height) were used ) The container 5 was placed on the table 7 in front of the base of the Central part 1 of the tray. The inclination of the container 5 was performed using electric hoist with a carrying capacity of 5 tons. The angle of inclination of the container was 16 ^o . The steps 8 at the table do not allow the container to slide onto the tray when tilted. Cullet poured out through the unloading hatch 6. Opening in the side wall, the dimensions of the hatch were 1.8 x 0.6 (m). Cullet arrived on the central part of 1 tray installed at an angle to the horizon, equal to 16 ^o . This angle provided free sliding of the cullet on the surface of the tray made of steel (the angle of friction of the glass on steel is 15 ^o ).

The width of the central part of the tray was 2.4 m, i.e. with a margin of 300 mm on each side of the discharge hatch. The angle at the apex of the central triangular part of the tray was selected at 46 ^° , the length L of the central part of the tray along the material flow was 2.8 m.

The height H of the step was chosen experimentally and at the beginning of the side grooves was 0.2 m, at the end of the grooves, at the conveyor belt 0.3 m. The total width of the grooves was 500 mm, i.e. 250 mm each gutter. The width S of the conveyor belt is 600 mm, the angle β of its rise is 18 ^o ± 2 ^o (the friction angle of the glass on the glass is 11 ^o , the glass on the rubber conveyor belt is 22 ^o ). Adjustment of the elevation angle of the conveyor was carried out by two screw jacks in the middle part and an adjustable console console table in the rear.

The bottom of the gutters were made at an angle to the edge of the ledge at an angle δ of approximately 8 ^o . For precise pairing of the grooves with the conveyor belt and to prevent small fragments from falling onto the floor, the ends of the grooves at the place of pairing with the belt are equipped with a rubber apron 100 mm long, thereby compensating for belt vibrations and deformation of the channels.

 Hammer crusher type 9 MD - 5x5, design of the Research Institute "Mechanobr", St. Petersburg. The neck 10 of the crusher was 0.6 x 0.25 (m) in size. Crusher capacity up to 1500 kg / h. Therefore, the speed of the conveyor belt was equal to 9 m / min.

 The device for separating bulk materials of the proposed design per shift (6 hours) separates up to 9 tons of material. The unit worked for 3 months, malfunctions and wear of the conveyor belt during operation were not recorded. Separation in a monolayer was carried out automatically and without fail.

 Thus, an efficient, reliable and easy-to-use installation that does not require adjustment of the dosage of material has been proposed for the separation of bulk materials. The installation does not require the use of energy-intensive units such as a vibratory tray and an electric system for automatically adjusting the supply of material.

 Operation without vibration mode minimizes the generation of glass dust.

Claims (1)

A device for the dry separation of solid bulk materials stored in bulk, mainly sheet glass battle, including a flow former arranged along a longitudinal axis of symmetry in the form of a tray installed at an angle that allows the material to slide along its surface and a conveyor belt associated with it, mounted with a lift up, characterized in that the working surface of the tray is made of central and lateral parts, the contour of the central part has the shape of a triangle located at the base we take to the unloading hatch of the container, with a width B not less than the width of the unloading hatch, and a vertex mating with a straight section of the conveyor belt, while the angle α at the apex of the triangle is found from the condition 20 ^o <α <80 ^o , the side parts of the tray are made in the form of adjoining to the sides of the triangle and the gutters converging at its apex, made with a step down, increasing towards the conveyor belt, and with a total width not exceeding the width of the working zone of the conveyor belt, the angle of elevation β of the conveyor belt is found from the relation T ₁ ^o <β <T ₂ ^o , where T ₁ is the friction angle of the material to be separated over the material to be separated; T ₂ - the angle of friction of the separated material on the material of the conveyor belt, the bottom of the gutters are made inclined towards the edge of the step by an angle δ, found from the relation δ = arctan (tgα / 2 • tgβ), while the depth of the gutter from the side opposite the step is not less than the depth of the ledge, the value of which is not less than 0.6 of the maximum size of the fraction.

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