RU2271278C2 - Screw press for squeezing out liquid from vegetable raw material - Google Patents

Abstract

FIELD: special-designation presses, namely screw type apparatuses for squeezing out liquid from vegetable raw material.

SUBSTANCE: press includes zeer arranged inside it auger drive shaft and mechanism for controlling pressure. Shaft for driving auger is in the form of trapezoidal cross-section spring. Last turn of spring is in the form of cone and it is coaxially mounted in mechanism for controlling pressure of press; apex of cone is turned inside zeer. Such design prevents jamming of press.

EFFECT: improved design, prevention of press jamming.

1 dwg

Description

The invention relates to presses for special purposes, in particular to screw devices for squeezing liquids from plant materials, juice, oil, etc.

The main working bodies of the pressing screw mechanism are a siege, a screw and a mechanism for controlling the pressure of pressing. The screw is an active working body of the press and is designed to create a pressure gradient in the volume of the pressed material and to move the latter along the axis of the screw, as well as to filter the squeezed liquid. Zeer is a passive working body of the press and is designed to filter squeezed liquid. The mechanism for controlling the pressure of the pressing ensures the coordination of the forces acting by the screw on the pressed material by the reaction forces of the material, sufficient to separate the pressed material into liquid and solid, by changing the area of the passage section.

The closest to the claimed technical solution for its functionality and technical essence is a screw press mechanism for squeezing oil from seeds (patent No. 1807944, IPC 5 V 30 V 9/14, published 07.04.93 in BI No. 13).

Compared with a whole-made screw shaft, the assembled screw drive shaft provides permeability and liquid outlet not only through the Zeer, but also through the shaft itself.

The perforation of the pressing screw shaft is carried out mainly by a set of many rings, cut screw washers and other elements assembled (mounted) on the drive shaft and tightened with a clamping nut. In this case, the filter slots of the pressing shaft, which is also a Zeer, are formed by the end surfaces of washers, rings, plates, wedges, etc. Additionally, various grooves, bevels, and indentations can be performed on the end surfaces of the elements. The linear size of the filter slots, i.e. their width, is determined by the design of the washers and, to some extent, by the force of the coupling nut.

The process of squeezing liquids from raw materials by pressure is mainly determined by the pressure value. During the process, the volume of compressible material decreases mainly due to the removal of fluid from it. In this case, the pressure should be constant. Engineering this is done by reducing the volume between the turns of the screw shaft to the output of the squeezed material. However, the following phenomenon is observed.

The value of the volume between each turn of the screw shaft - the value is constant in geometry. But the mass of the pressed material entering the space of the first turn is a variable value. It is determined by flowability, humidity, internal friction, natural density, particle size, etc. A variable mass with a constant volume leads to a variable density and, as a result, to a variable pressing pressure, which in turn leads to the phenomenon of non-spinning of the liquid or jamming of the material and stopping of the press. Both phenomena significantly worsen the quality indicators of the squeezing process.

Based on the analysis of analogues, including the nearest ones, the creation of the claimed invention was based on the task of developing such a design of the screw press pressing mechanism, during operation of which the following requirements are observed:

- the volume formed by the inner surface of the grain chamber and the outer surface of the screw shaft between each two adjacent turns should be a variable depending on the mass of the pressed material located in this space in order to eliminate the phenomenon of jamming;

- the screw of the pressing mechanism must be permeable to the squeezed liquid and the linear size of the grain slots should decrease with increasing pressing pressure in order to prevent the ingress of grain scree;

- the screw shaft must act on the mechanism for controlling the pressing pressure in order to automatically control the latter within the appropriate limits.

The tasks are carried out in the inventive screw press for squeezing liquid from plant materials containing a sieve, a screw drive shaft and a pressure control mechanism located inside the sieve, wherein the screw drive shaft is made in the form of a trapezoidal spring, and the last coil of the spring is made in the form of a cone, coaxially installed in the mechanism for regulating the pressure of the press with the direction of the taper inward of the sieve.

The drawing shows a General view of the claimed press. The press consists of a sieve 1, in the cavity of which a spring-loaded auger shaft is mounted 2. To regulate the pressing pressure, a pressure control mechanism is provided 3. The last turn of the spring auger shaft ends with a cone 4, coaxially mounted in the pressure control mechanism with the taper direction inward of the siege. The cone and the pressure control mechanism form an annular gap 5 for the output of the solid fraction of the squeezed material. The inner surface of the Zeer and the outer surface of the spring screw shaft form the inter-turn volume 6. Inside the spring shaft, a cavity 7 is made for collecting the liquid fraction. To withdraw fluid from the cavity 7 in the front hub 8 channel 9 is made.

Press works as follows.

The squeezed material is captured by the coil of the spring shaft and transferred from the coil to the coil through the inter-turn volume 6. The technological pressing pressure is set by the pressure control mechanism 3 by setting the corresponding size of the annular gap 5. Through this annular gap, the solid part of the pressed material leaves, and the liquid fraction leaves the inter-turn space 6 through slots zeera 1 and the gaps of the spring screw shaft 2 into the cavity 7 and channel 9.

Due to the fact that a different amount of mass of the squeezed material enters the first interturn space with different physical and mechanical characteristics in size, humidity, porosity, oil content, a local increase in pressure occurs in a particular turn. Due to this, this coil is twisted according to the law of a cantilever beam, that is, its diameter is reduced. The working volume of this inter-turn space increases, which leads to equalization of the pressing pressure. Reducing the diameter of this coil will lead either to an increase in the neighboring ones, if the pressing pressure in each coil allows, or to an elongation of the spring screw shaft. The extension will lead to the movement of the cone 4, which will provide an increase in the gap in the mechanism 3 and, as a result, the solid fraction will be removed more and will lead to a decrease in the pressing pressure. With a decrease in the pressing pressure due to the stiffness of the spring, the coils restore their working position.

Claims (1)

A screw press for pressing liquid from plant materials, containing a sieve, a screw drive shaft and a pressure control mechanism located inside the sieve, characterized in that the screw drive shaft is made in the form of a trapezoidal spring, and the last coil of the spring is made in the form of a cone coaxially mounted in the mechanism regulation of the pressure of the press with the direction of the taper inward of the zeera.