RU2750158C1 - Extruder - Google Patents

Abstract

FIELD: food and processing industries.SUBSTANCE: invention relates to equipment for the production of extruded products and can be used in the food and processing industries of the agro-industrial complex. An extruder for the food and agricultural industry is described, including a drive, a working chamber with a combined screw located inside it, a die, a loading hopper and an unloading chamber for extrudate output, while the combined screw located inside the working chamber consists of six zones: a loading and transportation zone, a pre-compaction zone, an evacuation zone, a liquid component injection zone, a homogenization zone and a pressure stabilization zone; in the first zone of loading and transportation, the diameters of the shaft and turns of the auger, as well as the pitch of the turns of the auger, are constant, at the end of this zone, the turn of the auger has a gap, in the place of which an annular track is made on the shaft of the auger, in the second zone of pre-compaction the shaft of the auger has a constant diameter but it is larger than in the zone of loading and transportation. Thickness of the turns is increased. At the end of the second zone the turn of the screw has a break, in the third evacuation zone the diameter of the screw shaft is made conical (constantly increasing). There is a branch pipe in the body at the beginning of this zone. The branch pipe is used for connecting with a vacuum line, in the fourth zone for the introduction of liquid components, the shaft diameter and the pitch of the turns are constant and, starting from this zone and up to the end of the screw, slots are made in the turns, and in the body at the beginning of this zone there is a branch pipe for injecting liquid components, in the fifth homogenization zone the diameter of the screw shaft is made conical (constantly increasing), in the sixth pressure stabilization zone, the shaft diameter is constant, and in the body along the length of this zones with a pitch equal to the distance between the breaks along the axis of the annular tracks, adjusting bolts are installed, the unloading chamber for the extrudate outlet is equipped with a device for adjusting the size of the outlet gap using a matrix movable in the horizontal plane.EFFECT: invention makes it possible to obtain an extrudate of a given composition.1 cl, 1 dwg

Description

The invention relates to equipment for the production of extruded products and can be used in the food and processing industries of the agro-industrial complex.

The closest in technical essence and the achieved effect is an extruder for food processing [US Pat. No. 2177702, IPC ⁷ A23R 1/12. Extruder for food processing / Ostrikov A.N., Rudometkin A.S., Abramov O.V., Vasilenko V.N. (RF). - No. 2000131809/12, Appl. 12/18/2000, Publ. 10.01.2002, Bul. No. 1], containing a working chamber with a loading branch pipe and a matrix, a screw of variable diameter and a drive. The extruder has a working chamber, which consists of five modules with different configurations of the body and the screw, the first module containing sequentially located zones of loading, mixing, compression and plasticization. The working chamber has a conical body with an inner diameter decreasing towards the matrix and an increasing screw shaft diameter in the compression and plasticization zones. In the mixing and plasticization zones, the screw turns have slots, the flow area of which in the mixing zone is larger than in the plasticization zone, the second module containing the first pressure stabilization zone has a constant diameter of the housing and the screw shaft, on which double-thread rhombic pins are located with a constant pitch profile. The working surfaces of the screw and the housing are made with increased processing purity, the third module, containing sequentially located compression and homogenization zones, has a conical housing with a decreasing taper towards the matrix and an increasing diameter of the screw shaft. The fourth module, containing the second zone of pressure stabilization, has a constant diameter of the screw shaft with double-thread pins of the rhombic profile located on it with a constant pitch, and the working surfaces of the screw and the housing are made with increased processing cleanliness. The fifth module, containing sequentially located zones of compression, homogenization and metering, has a decreasing step of cutting in the zone of compression and metering, in the second and third modules in the zone of homogenization the screw is made with reverse threading and slots in the turns of the screw.

The known extruder has the following disadvantages:

- the extrusion process in it is not fully adapted in accordance with the basic kinetic laws of the extrusion process;

- low quality of the resulting extrudates due to the impossibility of removing air and introducing liquid components;

- lack of pressure regulation in the pre-matrix zone, which causes an uncontrolled increase in pressure and extrudate temperature.

The technical problem of the invention is achieved by the fact that in the proposed extruder for the food and agroindustrial industry, including a drive, a working chamber with a combined screw located inside it, a matrix, a feed hopper and an unloading chamber for extrudate output, it is new that located inside the working chamber the combined auger consists of six zones: loading and transportation zones, preliminary compaction zones, evacuation zones, liquid components injection zone, homogenization zones and pressure stabilization zones; in the first zone of loading and transportation, the diameters of the shaft and turns of the auger, as well as the pitch of the turns of the auger, are constant, at the end of this zone the turn of the auger has a gap, in the place of which an annular track is made on the shaft of the auger, in the second zone of pre-sealing the shaft of the auger has a constant but larger than in the zone of loading and transportation, the diameter and thickness of the turns are increased, at the end of the second zone, the turn of the screw has a break, in the third zone of evacuation, the diameter of the screw shaft is made conical (constantly increasing), and in the body at the beginning of this zone there is a branch pipe for connecting to the vacuum -line, in the fourth zone of the introduction of liquid components, the diameter of the shaft and the pitch of the turns are constant and, starting from this zone and up to the end of the screw, slots are made in the turns, and in the body at the beginning of this zone there is a branch pipe for injecting liquid components, in the fifth homogenization zone the diameter of the shaft the screw is made conical (constantly increasing), in the sixth pressure stabilization zone, the shaft diameter is constant, and in the body along the length of this zone Adjusting bolts are installed with a step equal to the distance between the discontinuities along the axis of the annular tracks, the unloading chamber for the extrudate outlet is equipped with a device for adjusting the size of the outlet gap using a matrix movable in the horizontal plane.

The technical result of the invention is to obtain an extrudate of a predetermined composition by evacuating the processed product and controlled introduction of liquid thermolabile components, as well as regulating the pressure and temperature in the pressure stabilization zone using adjusting bolts, and adapting the extrusion of products with a high content of valuable thermolabile components in accordance with the main kinetic laws of the process.

FIG. 1 shows a general view of an extruder for the food and agricultural industries.

An extruder for the food and agricultural industry includes an electric motor 1, a gearbox 2, a feed hopper 3, a combination auger 4, a nozzle 5 for connecting to a vacuum line, a nozzle 6 for introducing liquid components, adjusting bolts 7, a die 8, a discharge chamber 9 for the exit of the extrudate, a device for adjusting the size of the exit gap using the adjusting rod 10, the unloading chute 11, the working chamber 12 (Fig. 1). Slots 13 are made in the turns of the screw 4.

Inside the working chamber 12, a combined auger 4 is installed, consisting of six zones: zone I for loading and transportation, zone II for preliminary compaction, zone III for evacuation, zone IV for introducing liquid components, zone V for homogenization and zone VI for pressure stabilization (Fig. 1).

The device for adjusting the size of the outlet gap using the adjusting rod 10 and the unloading chute 11 form the VII unloading zone.

Structurally, the combined auger 4 (Fig. 1) is made as a composite of separate auger turns, differing in pitch and diameter, and intermediate rings, fitted on a smooth shaft and fixed against turning with a key.

In the first zone of loading and transportation, the diameters of the shaft and turns of the screw, as well as the pitch of the turns of the screw, are constant. At the end of the I zone of loading and transportation, the turn of the screw 4 has a gap, in the place of which an annular track of constant diameter is made on the screw shaft.

In the II zone of preliminary compaction, the screw shaft 4 has a constant, but larger diameter than in the zone of loading and transportation. The thickness of the turns is increased, and at the end of the second zone, the turn of the screw has a break.

In the III zone of evacuation, the diameter of the screw shaft 4 is made conical (constantly increasing), and in the housing at the beginning of this zone there is a branch pipe 5 for connection with the vacuum line.

In the IV zone of the introduction of liquid components, the shaft diameter and the pitch of the turns are constant and, starting from this zone and up to the end of the screw, slots 13 are made in the turns, and in the body at the beginning of this zone there is a branch pipe 6 for injecting liquid components.

In the V homogenization zone, the diameter of the screw shaft 4 is made conical (constantly increasing).

In the VI zone of pressure stabilization, the shaft diameter is constant, and adjusting bolts 7 are installed in the body along the length of this zone with a step equal to the distance between the breaks along the axis of the annular tracks.

The unloading chamber 9 for the extrudate outlet is equipped with a device for adjusting the size of the outlet gap using an adjusting rod 10 using a die 8 movable in the horizontal plane.

The unloading chamber 9 is equipped with an unloading chute 11.

Starting from zone IV and up to the end of the auger, slots 13 are made in the auger loop 4, the presence of which in the auger loops leads to turbulence of the moving product and reduces the rate of product temperature rise due to the dissipation effect.

An extruder for the food and agro-industrial industry works as follows.

An adjustable electric motor 1 is switched on, which, through a gearbox 2, drives the combined auger 4 into rotation. The feedstock is fed into the loading hopper 3, from which it enters the I zone for loading and transporting the working chamber 12. When the auger 4 rotates, the processed product is transported inside the working chamber 12.

Here the product is intensively mixed and moves along the screw 4. Due to the fact that the diameter of the screw shaft in this zone is constant and the diameter and pitch of the screw turns are also constant, the product moves along the screw channel of the combined screw 4. At the end of the I loading and transportation zone, the turn the screw has a break, after which an annular track of constant diameter is made on the screw shaft. The purpose of the rupture of the screw loop is that it contributes to additional turbulence of the transported flow when moving the product from the I zone of loading and transportation to the II zone of preliminary compaction. Due to the fact that in the II zone the screw shaft 4 has a constant, but larger than in the I zone of loading and transportation, the diameter and thickness of the turns is increased, then there is a decrease in the working volume of the turn-to-turn space along the screw 4. Due to the fact that in this in the zone, the screw shaft has a constant but larger diameter than in zone I of loading and transportation, i.e. there is a decrease in the volume of the turn-to-turn space, then the product begins to thicken, displacing air. As a result, the processed product is compacted and compressed. At the same time, with the help of a branch pipe 5 connected to the vacuum line, an area of reduced pressure (vacuum) is created in the III zone and air is removed from it. Due to the rupture of the screw loop at the end of zone II and a decrease in the shaft diameter at the beginning of zone III of evacuation, optimal conditions for air removal have been created. Due to the fact that the diameter of the screw shaft 4 in it is made conical (constantly increasing), the product is compressed. As a result of a decrease in the free volume of turns in the direction of movement of the material, due to a decrease in the pitch and an increase in the diameter of the shaft from the beginning to the end of the screw shaft 4, the material is compressed. This creates pressure in the material. From the III zone of evacuation, the product moves to the IV zone of the introduction of liquid components, in which the diameter of the shaft and the pitch of the turns are constant, and slots 13 are made in the turns of the screw 4. Simultaneously, liquid components are introduced through the nozzle 6 located in the body at the beginning of this zone.

Subsequently, the product moves to the V homogenization zone. Due to the fact that in the V homogenization zone the diameter of the screw shaft is conical (constantly increasing), the pressure in it increases, which leads to the melting of small inclusions. The melt is intensively mixed by means of a screw 4 and turbulizes the flow.

In the second stabilization zone, the pressure and temperature fields of the material are re-equalized. The third compression zone allows you to obtain the required final pressure of the product, by reducing the pitch of the screw turns.

With further movement of the product into the VI zone of pressure stabilization, due to the fact that the shaft diameter is constant, the pressure is stabilized.

4 annular tracks of constant diameter made after rupture on the screw shaft are designed to move in the radial direction of the adjusting bolts 7. The bolts 7, when tightened, enter the interturn space of the VI zone of the working chamber 12, filling the space above the annular track, while the volume of the screw channel decreases, which in turn leads to an increase in the pressure of the transported stream.

In the turns of the screw 4 in this zone there are slots 13, between which on the shaft of the screw there are annular tracks 16. The product, passing through the slots 13 in the turns of the screw, is turbulized. The adjusting bolts 7, located above the annular tracks, when moving in the radial direction, change the volume of the screw channel, which in turn leads to an increase (when tightening the bolts 7) or decrease (when unscrewing the bolts 7) the pressure of the transported product flow.

The extruded material at the exit from the working chamber 12 meets with a device 10, which regulates the thickness of the exit slot using a movable die 8. The adjusting device 10 controls the pressure in the working chamber 12 of the extruder.

In the VI zone of pressure stabilization, a melt is finally formed that is homogeneous in structure and temperature, the presence of slots in the turns of the screw 4 contributes to the passage of the product and extrusion through the matrix 8.

The geometric dimensions of the slots 13 in the turns of the screw 4 in the IV, V and VI zones, as well as the number, pitch and diameter of the adjusting bolts 7 in the VI zone of pressure stabilization, depend on the properties of the processed material and the technological mode of processing.

With the help of the adjusting rod 10 located in the device for adjusting the size of the outlet gap, the required pressure value in the VI zone is regulated and set.

When leaving the extruder into the unloading chamber 9, as a result of a large pressure drop, the homogeneous mass swells (its explosion occurs). Due to the gelatinization of starch, the destruction of cellulose-lignin formations, its nutritional value is significantly improved.

The finished product is removed from the chamber 9 along the unloading chute 11.

The proposed extruder for the food and agricultural industry has the following advantages:

- the extrusion process in it is adapted in accordance with the basic kinetic laws of the extrusion process;

- obtaining an extrudate with a given chemical composition due to the use of controlled pressure along the length of the working chamber 12;

- the possibility of improving the quality of the extrudate due to evacuation and introduction of liquid thermolabile components and the use of softer, "sparing" temperature conditions and uniform processing;

- extrusion of various raw materials due to a smooth, gradual increase in temperature and pressure with their stepwise stabilization, necessary for the course of physicochemical changes in the main components of products;

- universalization of the extruder, i.e. its use in the extrusion of various products of plant or animal origin.

Claims (1)

Extruder for the food and agricultural industry, including a drive, a working chamber with a combined screw located inside it, a die, a loading hopper and an unloading chamber for extrudate output, characterized in that the combined screw located inside the working chamber consists of six zones: loading and transportation zones, zones of preliminary compaction, zones of evacuation, zones of injection of liquid components, zones of homogenization and zones of pressure stabilization; in the first zone of loading and transportation, the diameters of the shaft and turns of the auger, as well as the pitch of the turns of the auger, are constant, at the end of this zone the turn of the auger has a gap, in the place of which an annular track is made on the shaft of the auger, in the second zone of pre-sealing the shaft of the auger has a constant but larger than in the loading and transportation zone, the diameter and thickness of the turns are increased, at the end of the second zone the screw turn has a break, in the third evacuation zone the screw shaft diameter is made conical - constantly increasing, and in the body at the beginning of this zone there is a branch pipe for connecting to the vacuum -line, in the fourth zone of the introduction of liquid components, the diameter of the shaft and the pitch of the turns are constant and, starting from this zone and up to the end of the screw, slots are made in the turns, and in the body at the beginning of this zone there is a branch pipe for injecting liquid components, in the fifth homogenization zone the diameter the screw shaft is made conical - constantly increasing, in the sixth pressure stabilization zone, the shaft diameter is constant, and in the body along the length of this zones with a step equal to the distance between the breaks along the axis of the annular tracks, adjusting bolts are installed, the unloading chamber for the extrudate outlet is equipped with a device for adjusting the size of the outlet gap using a matrix movable in the horizontal plane.

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