RU2238138C1 - Device for granulation of viscous materials - Google Patents

Abstract

FIELD: equipment for granulation of high-viscous materials, such as resins, polymers; chemical and food-processing industries.

SUBSTANCE: proposed device includes inner cylindrical member secured on drive shaft, external envelope, unit for delivery of material to be granulated and mechanism for discharge of finished product. Inner cylindrical member is provided with longitudinal slots where plates are freely mounted. External envelope is shifted along vertical and horizontal axes relative to axis of symmetry of inner cylindrical member forming wedge-shaped clearance. External envelope is provided with radial holes in area of wedge-shaped clearance. External envelope is made in form of two engageable semi-envelopes of different radius; radius of envelope with radial holes is lesser. Device is provided with cooling unit for cooling the granulated product which is made in form of hermetic reservoir with extensible chute and flushing water circulating system.

EFFECT: reduced power requirements; enhanced operational reliability and safety.

3 cl, 5 dwg

Description

The invention relates to equipment for granulation (dosing) of highly viscous materials (resins, polymers, etc.) used in the chemical, food and other industries.

Known devices for granulation of floats, made in the form of vertical towers (Pozin ME Technology of mineral fertilizers. L., Chemistry, 1974, S. 225 and 249). The melt is pumped to the upper part of the tower, it enters a basket rotating at a certain angular speed and has radial holes on its side wall, and is squeezed out into the cavity of the tower by centrifugal forces. Drops of melt under the influence of gravity fall down and are cooled by a counter flow of air, turning into solid granules.

The disadvantages of this type of device include their increased dimensions due to the height necessary for cooling and hardening of the melt drops, as well as the significant difficulties in creating a centrifugal force of a certain size, necessary for squeezing high-viscosity material through the holes.

The closest claimed technical essence and the achieved effect is a device for granulating viscous materials (RF patent No. 2041068, 1992, class B 29 V 9/10), containing horizontally placed inner cylindrical element, an external heated shell with radial holes, node supply of granular material and the mechanism for unloading the finished product.

In this design, the outer shell rotates, and the coaxially placed cylindrical element in it is stationary. The metered material under pressure enters the inner cavity of the cylindrical element and through the radial hole into the annular gap formed by the inner surface of the outer shell and the outer surface of the inner cylindrical element, and then through the radial holes of the outer shell to the conveyor belt, where the metered granules are cooled and harden .

In this known construction, the cooling of granules on a conveyor belt requires considerable time, which affects the dimensions of the conveyor itself. In addition, a separate drive is required for the conveyor to operate. It should be noted that some products during granulation, for example resins, require rapid cooling of the granules to preserve the initial structure.

A high-pressure pump is required to force material to be dosed through all installation channels.

Outdoor cooling of the granular product is unacceptable for materials containing toxic or explosive and fire hazardous components, based on the safe operation of the installation and the protection of the environment from harmful emissions.

In this design there is no possibility of washing deposits of the dosed material in the channels of its supply without disassembling the device, which is inevitable when working with highly viscous materials.

The main design flaws: increased energy and material costs; large production areas occupied by the device; reduced reliability of the device due to its complexity; increased operating costs when working with highly viscous materials; reducing the safety of operation of the device in the presence of toxic, explosive and fire hazardous components in the granulation products, as well as the possibility of environmental pollution by harmful emissions.

The objective of the invention is the reduction of energy consumption for granulation of viscous materials; reduction of production space occupied by the device; increase the reliability of its work; improving the safety of operation of the device when granulating toxic, explosive and fire hazardous components. This is achieved by the fact that in a device for granulating viscous materials containing a horizontally placed inner cylindrical element, an external heated shell with radial holes, a granular material supply unit and a finished product unloading mechanism, according to the invention, the inner cylindrical element is provided with a drive shaft whose symmetry axis is offset along vertical and horizontal axes relative to the axis of symmetry of the outer heated shell, forming a wedge gap between the outer surface with the inner cylindrical element and the inner surface of the outer heated shell, while the radial holes are made on the outer shell in the zone of the wedge gap in its lower part. In this technical solution, when the inner cylindrical element is rotated, the granulated material enters the granulator, creates the pressure required for granulating the material, and conducts the granulation process.

It is advisable to make the heating unit of the outer cylindrical shell in the form of a jacket into which a coolant is supplied, placed on the outer surface of the heated shell without radial holes.

This solution allows you to intensify the process of heating the granulated material, without affecting the performance of the granulator.

It is advisable to equip the device with a granulation product cooling unit made in the form of a sealed container located below the heated shell and equipped with a drawer tray, as well as a washing liquid circulation system including a circulation pump and pipelines connecting the circulation pump to the granular material supply unit and the drawer tray, the pipeline connecting the circulation pump and the drawer, it is advisable to perform in the form of a flexible hose.

Such a constructive solution eliminates emissions of toxic and explosive and fire hazardous components of granulation products and provides the ability to flush the system from deposited granulation products without disassembling the system itself.

It is advisable to unload the finished granulation product in the form of a chain elevator associated with the drive shaft of the inner cylindrical element.

In this case, the need for a special drive for unloading the finished product is eliminated and the working area occupied by the device is significantly reduced.

It is advisable that the external heated shell be made in the form of two mating half-shells of different radius, and the radius of the half-shell with radial holes, forming a wedge gap between its inner surface and the outer surface of the inner cylindrical element, is smaller than the radius of the second half-shell mating with it.

With this embodiment of the outer shell, the energy consumption for granulating the product is reduced, and the larger the difference between the radii, the lower the energy consumption.

It is also advisable to make longitudinal grooves on the cylindrical surface of the horizontally placed inner cylindrical element, into which the plates can be freely mounted.

This constructive solution will limit the length of the obtained granules, and the more grooves there are, the shorter the granule will be.

Figure 1-5 presents the design of the proposed device.

Figure 1 shows a General view (longitudinal section) of the device; figure 2 is a section along aa (the position of the sliding tray when granulating the material); figure 3 is a view along BB (node unloading granular material); figure 4 - position of the sliding tray when flushing the granulation system with a solvent; figure 5 is a cross section of the outer shell when it is paired with two half-shells of different radius.

A device for granulating highly viscous substances contains an external heated shell 1. In the outer shell 1 there is a cylindrical element (rotor) 2, the axis of symmetry of which 3 is shifted relative to the axis of symmetry 4 of the outer shell 1 by h, forming between the inner surface 5 of the outer shell 1 and the outer surface 6 rotors 2 wedge clearance 7. In the wall of the outer shell 1 in the zone of formation of the wedge gap 8 made radial holes 9. The rotor 2 is mounted on the drive shaft 10, which is placed on the bearing bearings 11 and 12. Priv the bottom shaft using couplings 13 and 14 through the gear 15 is connected to the motor 16.

On the outer surface 17 of the shell 1 in a section devoid of radial holes 9, a shirt 18 is placed into which a heat carrier, for example steam, is supplied to heat the granulated material.

Bearing bearings 11 and 12 are mounted on the cover 19 of the granulation product cooling assembly 20. The cover 19 is hermetically connected by the casing 21 to the lower portion 22 of the outer shell 1, on which the radial holes 9 are made. In the cover 19 in the area bounded by the casing 21, a rectangular hole 23 is made form, the area of which is not less than the area of the lower section 22 of the outer shell 1.

The cooling unit of the granulation product 20 is made in the form of a rectangular sealed container equipped with nozzles 24 and 25, respectively, for supplying and discharging a cooling agent (for example, water), vertical partitions 26 and 27, and a sliding tray 28. The sliding tray 28 is equipped with a pipe 29 for connection the inner cavity 30 of the drawer with a flexible hose with a circulation pump (not shown).

In the cavity 31 formed by the vertical partition 27 and the walls of the capacity of the cooling unit 20, a finished product unloading mechanism is placed, which contains a traction chain 32, on which buckets 33 are mounted, intermediate sprockets 34 and 35 and driven 36 connected by a drive chain 37 with a shaft mounted 10 leading asterisk 38.

The device operates as follows. Through the supply unit 39, the granulated material is fed into the gap formed by the inner surface 5 of the outer shell 1 and the outer surface 6 of the rotor 2. When the rotor 2 is rotated, the granulated material is drawn into the wedge gap 7. Due to the decrease in the volume of the zone of the wedge gap 8, the pressure of the granulated material increases in it, under the action of which the material in the form of individual fragments (granules) is squeezed out through radial holes 9 and through a rectangular hole 23 enters the product cooling unit I 20, in which it is cooled by the refrigerant (water) supplied through the pipe 24 and discharged through the pipe 25. The cooled and hardened granules are deposited on the bottom 40, which is made with an inclination towards the vertical partition 27, and moved into the cavity 31, from which the buckets 33 mounted on the traction chain 32, in the form of the finished product are carried out of the cooling zone. At this stage of operation, the drawer tray 28 is removed from the cavity of the cooling unit (see figure 2).

To flush the internal cavities of the device from deposited granulation products, the drawer tray 28 is introduced into the cavity of the cooling unit 20 (see Fig. 4), a solvent is introduced through the supply unit 39, and when the rotor 2 rotates using a circulation pump (not shown), the solvent is repeatedly (up to required degree of purification) passes through the entire granulation system.

To ensure the necessary fluidity of the granulated material, which is especially important when granulating highly viscous resins, a coolant with the required parameters is supplied to the jacket 18 during the granulation process. Heating the outer shell 1 and rotor 2 is also necessary before starting the granulator in order to avoid hardening of the granulated product, which may affect its performance.

All the energy supplied by the electric motor 16 is mainly spent on overcoming the resistance of viscous friction between the surface of the rotating rotor and the layer of granular material. The thinner this layer, the greater the friction resistance. In the proposed device (see Fig. 5), the useful layer is the zone of formation of the wedge gap 8, formed by the inner surface 5 of the outer shell 1 and the surface of the rotor 2. Due to this wedge gap, the pressure required for extruding the granulated material through the radial holes 9 is created. Friction losses in the rest of the gap are useless and only lead to a decrease in the efficiency of the device. Therefore, it is advisable that the outer shell 1 be made in the form of two mating half-shells 41 and 42. The half-shell 41, forming a wedge gap 7, on which the radial holes 9 are made, has a smaller radius than the mating half-shell 42.

Studies have shown that if, with the same radius of the half-shells 41 and 42, the power consumption is taken to be 1.0, then with a ratio of the radii of these half-shells 0.725, the power consumption will be 0.6, i.e. will decrease by 40%.

When the rotor 2 rotates, the plates 43, placed in the longitudinal grooves 44, are pulled out from the grooves 44 by the action of centrifugal force and slide along the inner surface 5 of the outer shell 1, interrupting the jet forced through the radial holes 9 of the granulated material. The frequency of interruption of the jet or the length of the extruded granules is inversely proportional to the number of grooves 44 made on the surface of the rotor.

To exclude the exit from the grooves 44 of the plates 43 in the area of the half-shell 42, the half-shell 41 is equipped with limiters 45, while the radius of curvature of the limiter 45 is equal to the radius of the half-shell 41.

Claims (3)

1. A device for granulating viscous materials, containing a horizontally placed inner cylindrical element mounted on the drive shaft, with longitudinal grooves with plates freely mounted in them, an outer shell offset along the vertical and horizontal axes relative to the axis of symmetry of the inner cylindrical element with the formation of a wedge gap, in the zone of which on the outer cylindrical shell there are made radial holes, a node for supplying granular material and a mechanism for unloading the finished product, characterized in that the device is equipped with a cooling unit for granulating the product, made in the form of a sealed container located below the outer shell and provided with a pull-out tray, while the outer shell is made in the form of two mating half-shells of different radius, and the radius of the half-shell with radial holes has a smaller value . 2. The device according to claim 1, characterized in that it is equipped with a washing fluid circulation system, including a circulation pump and pipelines connecting the circulation pump to the granular material supply unit and the drawer tray, wherein the pipe section connecting the circulation pump and the drawer tray is made in form of flexible hose. 3. The device according to claim 1 or 2, characterized in that the mechanism for unloading the finished product is made in the form of a chain elevator associated with the drive shaft of the inner cylindrical element.

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