RU2271931C2 - Screw extruded for vegetable raw material pressing - Google Patents

Abstract

FIELD: mechanical engineering, in particular, screw extruders for pressing moisture out of the vegetable raw material.

SUBSTANCE: the extruder has two loading hoppers, screw conveyer with flights made integral with a tapered shaft having perforated sections, cylindrical perforated screen, counter-knives and filtering counterblades. It is provided with an adjusting cone. The conveyer has a double screw thread with the flight lead decreasing to the adjusting cone. The perforated screen is made with zones of smooth surface and perforated sections. The filtering counterblades are arranged by sections along the screw conveyer shaft in the zones of perforated sections of the shaft and screen.

EFFECT: enhanced quality of pressing of vegetable raw material and enhanced capacity of the screw extruder.

3 dwg

Description

The invention relates to mechanical engineering, in particular to devices of screw presses for squeezing moisture from plant materials. This press is designed to improve the quality of pressed vegetable raw materials and increase the productivity of the machine.

A known press (GH2) [1] for squeezing beet pulp containing two feed hoppers, a three-feed screw with a constant pitch of turns, made at the same time with a perforated shaft of a conical shape, a counter blade, a cylindrical perforated sieve, an adjustment cone, the disadvantage of which is one-sided radial compression of the pulp in the working chamber of the press, a low degree of dehydration of the pulp.

Also known is a press (SU 175394 A1, 11/15/1965, 30 V 9/14) [2] for squeezing wort from the pulp, containing a screw, the shaft of which is hollow, intermittent turns, loading hopper, adjusting cone, wort collection trays, perforated bushings that fit freely on the screw shaft and overlap windows made on the screw shaft in the gaps between the turns.

The disadvantage of this press is that due to the constant rotation of the shaft, wort filtration through perforations of the bushings in the shaft cavity will occur unevenly, due to the successive penetration of the wort into the windows made in the shaft, then onto a continuous surface located radially between the windows. Also during squeezing, the pressed pulp can become clogged between the screw shaft and perforated bushings, which will increase the load on the shaft in areas weakened by windows and destroy it.

A known press for pressing (SU 1639970 A1, 04/07/1991, 30 V 9/12) [3], comprising a hollow shaft, a screw made double-entry with decreasing pitch of the turns, a loading hopper, a perforated cylinder, devices for removing the pressed material and liquids.

The disadvantages of this design are: one-sided removal of the squeezed liquid towards the perforated cylinder and the absence of devices in the working chamber that prevent radial rotation of the squeezed material, as a result of which the working chamber of the press is not uniformly filled, its productivity and quality of squeezing are reduced.

The closest adopted for the prototype is a screw press for the extraction of wet materials (SU 1821396 A1, 06.16.1993, 30 V 9/14) [4], containing two feed hoppers, filter cartridge cassettes, a screw, the turns of which are made at the same time as perforated conical shaft, counterblades, cylindrical perforated sieve.

The well-known press [4] has a number of disadvantages, namely, in its design there is no adjusting cone providing optimal pressing pressure at the exit of the press during its operation. Cartridges of filter elements allow more complete removal of liquid from the material only in the middle and at the end of the working chamber of the press. Also, due to the design features of the filter element cartridges, the screw shaft is prefabricated (the assembly zone (groove in the shaft) falls between the pressing zones I and II, opposite the filter element cartridges located in the middle of the press), this element has weakened its design. This is explained by the fact that when the material approaches from zone I to the annular row of filter element cartridges, the living section of the press working chamber is significantly reduced, which creates additional pressure on the squeezed material, which is transmitted in all directions, including the shaft. After passing through the filter elements, the material enters the working chamber, where its live section is much larger, as a result of which there is a sharp drop in pressure inside the press, and the screw shaft undergoes bending and torsion in this place. And since in this zone it consists of separate parts, then there is a high probability of its failure. Also, during the spin cycle, the material will penetrate, encountering the sharp edges of the upper plates, into the area between the filter element section and the screw shaft, where the bolted joints of the upper and lower plates are located. As a result, the squeezed material is clogged in the specified area and is subjected to undesirable additional grinding by the bulging heads and the ends of the bolts and nuts, which leads to excessive saturation of the liquid with dry substances of the squeezed material. The fastening of the filter element cartridges on the windows made in the case and the cylindrical screen of the press also weaken its design, since it occupies the entire annular space, and therefore, divide the case and the sieve into two parts.

The task of the claimed invention is to improve the quality of squeezing of vegetable raw materials and increase the productivity of the machine.

The technical result of the invention is provided due to the fact that the claimed press is equipped with an adjusting cone, the screw is made two-way with decreasing the pitch of the turns to the adjusting cone, and the perforated cylindrical sieve and the screw shaft are made with zones of smooth surfaces and perforated sections. Filtering counterblades are arranged in sections in the areas of perforated sections of the shaft and sieve. This arrangement of filtering counterblades allows you to loosen the pressed mass and filter the liquid from the entire inter-turn space, during the entire pressing cycle. Also, fluid filtration is carried out through perforated sections of the shaft and cylindrical sieve. In turn, the zones of smooth surfaces in the upper and middle parts of the shaft and sieve provide a significant increase in the pore pressure of the liquid in the cells of plant materials.

Figure 1 shows the described press, General view; figure 2 - layout of the upper filtering counterblades; figure 3 - layout of the lower filtering counterblades.

The screw press for squeezing vegetable raw materials contains a perforated cylindrical sieve 2 installed in the housing 1, inside of which there is a vertical perforated hollow shaft of the screw 3 with two-pass pressing turns 4. The pitch of the turns decreases to the adjusting cone. The shaft and sieve have zones of continuous surfaces 5, 6, which do not remove moisture. Inside the working chamber there are installed counterblades 7, filtering counterblades 8-13 and an adjusting cone 14. To ensure the loading of plant material into the working chamber of the press, loading bins 15 are installed on the housing.

A screw press for squeezing plant materials works as follows.

The plant mass enters the hoppers 15, where it is picked up by turns 4 and is subjected to initial compression, while air is removed from it. Then the squeezed mass is transported to zone 5. There is a significant increase in the pore pressure of the liquid in the cells of plant materials. Further spinning is accompanied by fluid filtration through perforations of the shaft 3, sieves 2 and filtering counterblades 8-10. At the next stage, in zone 6, there is a repeated compression of the raw material, an increase in the pore pressure of the liquid in it, without filtering it. Then the raw material enters the lower part of the press, where liquid is finally removed from it through perforations of the shaft 3, sieves 2 and filtering counterblades 11-13. The layout of the counterblades 7 and filtering counterblades 8-13 guarantee the prevention of mixing, radial movement of the material in the working chamber of the press and loosen it. The optimal pressing pressure at the exit of the press is created by the adjusting cone 14.

The desired effect is achieved as follows. When the material passes in zones 5 and 6, continuous, non-perforated surfaces of the shaft and sieve, it undergoes constant compression from the side of the conical shaft and the turns of the screw. In these zones, for a short period of time, a significant increase in the pore pressure of the liquid occurs, which contributes to the maintenance of the optimal filtration rate for a longer time during further extraction than in the known presses [2, 3]. In the zones of perforations of the shaft, cylindrical sieve and filtering counterblades 8-13, due to their arrangement, intensive liquid filtration will take place from the material saturated with it during the entire extraction process. The filtering counterblades 8-13 during the spinning process will gradually divide the material flow into equal parts, thereby each time reducing the length of the liquid filtration path from the least dehydrated layers. All this contributes to the creation of new filtration channels throughout the volume of the material during the entire pressing cycle.

Information sources

1. Machines and equipment for pressing in the sugar industry. - M.: Mechanical Engineering, 1980. - 113 p. silt.

2. Ivanenko A.V. Press - aut. certificate SU 175394 A1, B 30 B 9/14.

3. Levchenko V.V. The screw press for an extraction - a car. certificate SU 1639970 A1, 30 V 9/12.

4. Gadzhimuradov G.T., Scherbakov A.M., Kolomiyets A.V., Shalygin V. B., Grechanichenko V. I. Press for the extraction of wet materials - ed. certificate SU 1821396 A1, B 30 B 9/14.

Claims (1)

A screw press for squeezing liquid from plant materials, containing two feed hoppers, a screw with turns made integral with a conical shaft having perforated sections, a cylindrical perforated sieve, counter-knives and filtering counter-blades, characterized in that it is equipped with an adjusting cone, the screw is made of double-feed with a decrease in the pitch of the turns to the adjusting cone, and the perforated sieve is made with zones of smooth surfaces and perforated sections, while the filtering counterblades are located sections along the screw shaft in the areas of perforated sections of the shaft and sieve.

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