RU2848801C1 - Screw press for squeezing liquids - Google Patents

Abstract

FIELD: screw press.

SUBSTANCE: invention relates to a screw press for squeezing liquid. The technical result is achieved by a screw press, which includes a housing, a screw, a set of fixed rings installed coaxially with the screw with a gap between them by means of bosses, and a set of parts that move relative to the rotating screw during the operation of the press. In this case, the fixed rings 4 have smooth through holes evenly spaced around the circumference for installing threaded parts 7. The bosses 5 are made in the form of bushings installed between the fixed rings 4 on the threaded parts 7 with a gap. The parts that move relative to the axis of the rotating screw during press operation are additional movable rings 6, installed coaxially with the screw between the fixed rings 4 with the possibility of movement in the gap between them. The amount of movement is determined by the difference between the diameter of the circle inscribed in the space bounded by the outer surfaces of the bosses 5 and the outer diameter of the movable rings 6. Additionally, the press includes two flanges 8 installed at the ends of the outer bosses 5. The set of fixed rings 4, bosses 5 and flanges 8 is fastened with threaded parts 7 through through holes in the fixed rings 4 and secured to the end of the screw housing 1.

EFFECT: reduction in the duration of periodic maintenance of the screw press, elimination of the need for special tools to clean the liquid drainage holes, as well as elimination of the need for a steam generator and corresponding steam pipes for the same purposes, possibility of significantly increasing the pressure in the housing cavity.

5 cl, 3 dwg

Description

The invention relates to presses and can be used, in particular, in the food and chemical industries, in the production of building materials and in agriculture.

It is known that screw-type presses are widely used for squeezing liquids from raw materials of various types and purposes.

Another common design for such presses is one with so-called sieve chambers or sieve sections, which are a housing element with longitudinal or transverse openings for draining the separated liquid. The smallest opening width is selected to accommodate the amount of liquid being drained and to prevent the solid phase (cake) from passing through the opening. In some cases, screens are used. However, this carries a risk of press failure: if the pressure in front of the screen exceeds a critical value, the screen may fail.

Further, in the context of this application, the terms “cake” and “meal” will be used conditionally as synonyms.

The shell will be called the solid phase obtained after separating the liquid from the raw material.

A vegetable oil press is known, comprising rotors mounted in a housing made of alternating solid and perforated sections (patent RU 2071917, published January 20, 1997). According to the known solution, the arrangement of the solid and perforated sections in the housing corresponds to the arrangement of the groups of grinding and screw attachments on the rotors.

The disadvantages of the known solution include the complexity of the rotor design, due to the need to create sequentially arranged groups of grinding and screw attachments.

A screw press is known, comprising a seed cylinder formed as a set of rings and an auger placed therein, wherein the rings are installed with a gap relative to one another (A.S. SU 1460878, published 10/27/1996). According to the known solution, the rings are installed with a gap relative to one another by means of bosses, one of the end surfaces of each ring is made conical, in each ring on the inner cylindrical surface are longitudinal projections and an annular groove, and on the conical end of each ring an annular section is formed on a smaller diameter, parallel to the flat end. The bosses are located on the conical surface.

Common drawbacks of known solutions include the risk of clogging the oil drain holes with solid phase products, particularly oil cake or oil meal. All screw presses require periodic cleaning of the holes to maintain their functionality (see, for example, OIL EXTRACTOR EUJ-702 Oil Extraction Nozzle. Operating Manual. - sanaproducts.ru, vsesoki.ru, St. Petersburg, 2020; URL: https://eco2u.ru/docs/instructions/piteba/oil-piteba.pdf (accessed: 11.01.2025)). Cleaning, depending on the size of the press, can be performed with a knife, a special brush, or steam (see, for example, https://studme.org/424058/tehnika/osobennosti_ekspluatatsii_oborudovaniya_proizvodstva_kormovoy_produktsii (accessed: 11.01.2025)). In any case, cleaning the liquid outlet holes requires, firstly, interrupting the press's operation and, secondly, expending resources on its implementation.

The closest prototype of the claimed invention in terms of the set of essential features is a universal press for obtaining edible vegetable oil, containing a housing, a screw, a set of rings with grooves and a set of parts that, during operation of the press, move relative to the axis of the rotating screw without being mechanically connected to it (patent RU 2353521, published 04/27/2009. Bulletin No. 12). According to a known solution, a set of rings with grooves forms a zeer cylinder, in the annular grooves of the rings, made with end conical surfaces, annular springs with end conical surfaces are installed with the formation between the said end surfaces of a gap for the oil outlet, wherein the annular springs are made with the possibility of adjusting the said gap for the oil outlet, and the depth of the annular groove of the ring and the width of the annular spring are selected from the condition of excluding the exit of the spring from the groove of the ring in the assembled zeer cylinder, wherein the end conical surfaces of the rings and the end conical surfaces of the annular springs are located in parallel, and each annular spring is provided with a lock to prevent the oil from being pressed through it, wherein the end surfaces of the lock are made conical to ensure the displacement of the oil from the lock when the annular spring is compressed, the said annular springs are made with the provision of decompression in the radial direction with a decrease in the gaps for the oil outlet when the pressure in the zeer cylinder increases and compression in the radial direction with an increase in clearances for oil release when the pressure in the seizing cylinder decreases, and the maximum diameter of the annular spring is limited by the annular groove of the ring.

Disadvantages of the known solution include the technological complexity of manufacturing the device, due to the need to produce springs that require specialized materials and technologies. Furthermore, the known solution constantly changes the diameter of the ring springs due to pressure pulsations in the cavity in the housing around the auger. This creates additional risks of spring breakage and, consequently, press failure. When the pressure in the housing around the auger decreases, the ring springs compress, the gap between them and the stationary rings widens, and solids such as pulp, cake, etc., can enter the container along with the separated liquid.

The technical objective of the present invention is to increase the efficiency of a screw press for squeezing out liquid.

The technical result of implementing the present invention is a reduction in the duration of periodic maintenance of the screw press. An additional technical result of implementing the invention is the elimination of the need for a special tool for cleaning the liquid drainage holes, as well as the elimination of the need for a steam generator and associated steam lines for the same purpose. Another technical result is the ability to significantly increase the pressure in the housing cavity. This is of practical importance when working with strong feedstock particles: not only when the ultimate goal is to obtain a liquid product, but also when the purpose of processing the feedstock is to dry it for subsequent molding.

The solution to the technical problem is achieved by implementing the following design measures in a screw press, which contains a housing, a screw, a set of fixed rings installed coaxially to the screw with a gap relative to each other by means of bosses, and a set of parts that perform movements relative to the rotating screw during press operation:

- the fixed rings have smooth through holes evenly spaced around the circumference for installing threaded parts,

- the bosses are made in the form of bushings installed between fixed rings on threaded parts with a gap,

- the parts that perform movements relative to the axis of the rotating screw during operation of the press are additional - movable - rings installed coaxially to the screw between the fixed rings with the possibility of movement in the gap between them, and the amount of movement is determined by the difference between the diameter of the circle inscribed in the space limited by the outer surfaces of the bosses and the outer diameter of the movable rings, and the movable rings can have a forced drive and/or be mechanically connected to a source of ultrasonic vibrations.

The design of the proposed screw press is explained by drawings (Fig. 1, Fig. 2).

Fig. 1 shows a longitudinal section of the proposed screw press.

Fig. 2 shows a close-up, schematic view of the fixed rings, movable rings and bosses.

Fig. 3 shows a close-up view of a fragment of the end surface of the movable ring 6 with recesses.

The positions indicate:

1 - press body,

2 - auger,

3 - chambers for squeezing out liquid,

4 - fixed rings installed with axial clearance,

5 - bosses (spacer bushings),

6 - movable rings,

61 - recess on the end surface of ring 6,

7 - threaded elements,

8 - body parts.

In the figure, reference numerals designate only those elements of the screw press that contribute to the claimed technical result. Design features of other elements of the screw press are not subject to patent protection under this application.

Chamber 3, formed by a set of fixed rings 4 and spacer rings 5, tightened by threaded elements 7, with movable rings 6 and housing parts 8 installed between the fixed rings 4, forms an assembly unit, which may also be called a cassette. The number of cassettes may be arbitrary, determined by the type of raw material used, the permissible residual liquid content in the shell, and other factors known to those skilled in the art.

Fig. 1, as an example that does not exclude other embodiments of the invention, shows a screw press including three cassettes.

Fig. 2 shows, as an example that does not exclude other embodiments of the invention, a screw press in which the cassettes (chambers 3) are pulled together by four threaded elements 7, wherein the inner cylindrical surface of the rings is formed with four through partial holes (dimples). The number of threaded elements 7 and the shape of the depressions (protrusions) on the inner cylindrical surface of the rings may differ from that shown in Fig. 2. In Fig. 2 and Fig. 3, the screw 2 is not shown conditionally.

The first cassette, on the loading hopper side, is attached to the housing 1 by any method known in the art. It is preferably secured by threaded elements, such as studs, bolts, or special clamps.

If there is more than one cassette, they are mounted coaxially and fastened together using any method known in the art. The preferred method of fastening them is also threaded elements, such as studs, bolts, or special clamps.

Fig. 1, as an example that does not exclude other embodiments of the invention, shows a screw press comprising three cassettes fastened together and to the body 1 using clamps.

The height of the bosses 5 and, accordingly, the axial clearance between the fixed rings 4 may be the same or different in different cassettes. The movable rings 6 may have the same or different thicknesses.

The movable rings 6 may have a forced drive for their movement (not shown in the figure). The drive design may be any known from the prior art and is not the subject of protection under this application.

The movable rings 6 can be connected to ultrasonic vibration emitters (not shown in the figure). The frequency and amplitude of the vibrations transmitted to the movable rings 6 are determined by the characteristics of the raw material being processed in the screw press, the objective to be achieved during processing, and are not the subject of protection under this application.

Preferably, the end surfaces of the movable rings 6, which contact the surfaces of the fixed rings 4, are provided with recesses 61, evenly spaced around the circumference, shaped in plan view as two diverging rays with an opening angle extending from the ring's axis of rotation to the periphery. The bottom of the recesses may be flat or concave. The number of recesses is determined by the diameter of the movable ring 6. In the applicant's experience, the presence of recesses 61 on the ends of the movable rings 6 facilitates self-cleaning of the gap between the movable rings 6 and the fixed rings 4.

The screw press for squeezing out liquid proposed as the present invention operates as follows.

The raw material enters the loading hopper of the screw press (not indicated by a position in the figure), is captured by the screw turns and is transported to the cassette (chamber 3) for squeezing out the liquid.

According to the applicant's experience, the pressure in the meal during screw press operation is distributed unevenly across the screw's transverse plane. In the proposed design, this results in rings 4 and 6 experiencing resultant forces of varying magnitude and direction in this plane. The movable rings 6, carried by the meal, rotate at small angles within the gap between adjacent fixed rings 4. This effectively self-cleans the gap, eliminating the risk of clogging with cake. Furthermore, as noted above, the movable rings can be driven by an external, forced-action drive.

In this case, the movable rings 6 are made in the form of fairly simple parts, are not spring elements, do not work in bending and have minimal risks of destruction.

Example 1 of the invention.

The applicant mass-produces screw presses in accordance with the proposed invention at its own production facilities. The presses come in various designs, with varying numbers of cassettes, and are used by consumers, in particular, to extract juices such as sea buckthorn, viburnum, and currant, as well as to separate liquid from horse and cow manure.

The applicant mass-produces screw presses in accordance with the proposed invention at its own production facilities. The presses come in various designs, with varying numbers of cassettes, and are used by consumers, in particular, to extract juices such as sea buckthorn, viburnum, and currant, as well as to separate liquid from horse and cow manure.

To date, 16 screw presses of the proposed design, designed for various throughputs (from 0.05 t/h to 2 t/h), have been manufactured and are in operation. During operation (the longest period to date has been 36 months, including 7 months of continuous operation in three shifts, and the remainder of the time in one-shift (5 months) and two-shift (24 months) operation), the operator has never cleaned the presses' fluid drain holes. The equipment operates flawlessly.

Example 2 of the invention.

A batch of screw presses for sunflower oil production is currently in production. The end surfaces of the moving rings of this batch of presses are knurled with flat-bottomed indentations ranging from 0.5 to 0.8 mm deep. Extensive testing has demonstrated more effective self-cleaning of the screw presses.

Claims (5)

1. A screw press for squeezing out liquid, including a housing, a screw, a set of fixed rings installed coaxially to the screw with a gap relative to each other by means of bosses, and a set of parts that perform movements relative to the rotating screw during operation of the press, characterized in that in the fixed rings (4) uniformly spaced smooth through holes are made along the circumference for installing threaded parts (7), the bosses (5) are made in the form of bushings installed between the fixed rings (4) on the threaded parts (7) with a gap, the parts that perform movements relative to the axis of the rotating screw during operation of the press are additional - movable - rings (6), installed coaxially to the screw between the fixed rings (4) with the possibility of movement in the gap between them, and the amount of movement is determined by the difference between the diameter of the circle inscribed in the space limited by the outer surfaces of the bosses (5) and the outer diameter of the movable rings (6), additionally includes two flanges (8), installed at the ends of the outer bosses (5), and the set of fixed rings (4), bosses (5) and flanges (8) are pulled together by threaded parts (7) through through holes in the fixed rings (4) and secured to the end of the body (1) of the auger. 2. A screw press according to claim 1, characterized in that it includes more than one set of fixed rings (4), bushings (5) and flanges (8), wherein said sets are installed in series, coaxially to the screw and connected to each other. 3. A screw press according to item 1, characterized in that the movable rings (6) have a forced drive for their movement. 4. A screw press according to item 1, characterized in that the movable rings (6) are connected to ultrasonic vibration emitters. 5. A screw press according to the preceding points, characterized in that on the flat end surfaces of the movable rings (6) there are uniformly made depressions (61), uniformly located around the circumference and having in plan the shape of two diverging rays with an opening angle from the axis of rotation of the ring to the periphery.