RU2598909C2 - Method and device for grinding grain - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: group of inventions relates to devices for grinding and grinding on such devices. Device and method of grinding can be used in food industry and fooder preparation shops. Device for two-stage grinding of fodder grain comprises a bin, garbage catcher, magnetic separator, shutter, hammer drum, deck, counterdrive, electric motor and frame. Main working element - hammer drum, is supplemented with a roll section, and deck to increase probability of collision of hammers with defective grains or their particles are made in form of scattering and collecting sections. Grain milling method using above described device consists in that grinding process is divided into two stages. At first stage elastic properties of material are damaged. At second step plastic properties are violated and grains are finally broken down.

EFFECT: device and method of grinding provide improved quality of ready product due to more uniform granulometric composition, as well as reduced power consumption of grain grinding process.

2 cl, 4 dwg

Description

The invention relates to a device for grinding grain and can be used in the food industry and feed preparation workshops.

Known hammer crusher (RF patent No. 2477180, B02C 13/04, published 03/10/2013). It contains a casing of the crushing chamber with a lid, on the outer surface of which a stone separator is mounted. An electric motor is fixed on the housing, on the shaft of which an external fan and a hammer rotor are installed. The hammer rotor is made in the form of a hub with internal and external disks, between which there are axes, each with a set of hammers. The crushing chamber is formed by a lid, an external fan disk and a deck.

The disadvantage of the crusher is a large amount of dust fraction in the finished product and high energy intensity,

A known roller mill (RF patent No. 2465050, B02C 4/06, published October 27, 2012), which includes three horizontally mounted rolls forming two inter-roll gaps between the middle high-speed and two low-speed rolls, the bearings of the high-speed and low-speed rolls. The inter-gear transmission contains an interchangeable pair of gears mounted respectively on the high-speed roll and the intermediate axis, and a flexible transmission connecting the pulleys of the two low-speed rolls and the gear pulley of the intermediate axis. The entire structure is mounted on a bed and is driven by an electric motor.

The disadvantages of this technical solution are the difficulty of obtaining a given grinding module, high metal consumption, the absence of a device to prevent foreign material from entering the working area.

The objective of the present invention is to improve the quality of the finished product by obtaining a more uniform particle size distribution and reducing the energy consumption of the process of grinding grain.

To solve the problem in the proposed method, the process of grinding grain is divided into two stages. The first is the microdamage of grain by destroying the elastic properties of the material. The second is a violation of the plastic properties of grain and its complete crushing into particles.

This problem is solved due to the fact that to the main working body - the hammer drum, a roller section with an adjustable inter-roll gap is added.

A device for implementing this method (Fig. 1) comprises a hopper 1 with a shutter 2, a trap 3, a magnetic separator 4, a roller section consisting of a fixed shaft 6 and a movable shaft 12, a mechanism for adjusting the rolling gap 5, a typical meshless drum 8 s hammers 13, collecting and scattering decks 9, an electric motor 10 with a speed controller and a counter-drive 7. The whole installation is mounted on a frame 11.

The mechanism for adjusting the rolling gap (Fig. 3) consists of an adjusting rod 1 with a movable stop 2, which is pivotally attached to the bearing housing 3 of the movable roller, spring 4 and nut 5, which is supported on the housing 6.

The sensitivity of the movable roller is determined by the selection of the spring 4 and its compression ratio by the movable stop 2. The adjusting device is also a safety device in case a foreign body enters the working gap.

The proposed method is as follows: grain, from the hopper 1 with the shutter 2 open, passing the trap 3 and the magnetic separator 4, falls on the roller section, consisting of a fixed shaft 6 and a movable shaft 12 and a mechanism for adjusting the rolling gap 5. The gap between the rollers allows the grain receive microdamage while remaining intact. The effect of increasing deformation is observed. Further, the crushed material with the obtained structural defects falls on a typical lattice-free hammer drum 8, the working speed of the hammers of which is 35–40% less than the destructive one, according to V.P. Goryachkina (V.P. Kovalenko, I.M. Petrenko Mechanization of technological processes in animal husbandry - Krasnodar, Agroprompolygraphist, 2003. - 432 pages: ill. Textbooks and teaching aids for students of higher educational institutions, p. 73), where finally collapses. Particles of grain, colliding with hammers 13, first fall on the collecting sections of the deck 9, and with a secondary rebound from the hammers, on the scattering sections of the deck. Thus, the probability of collision of material with hammers is increased and the time spent by the grain in the working chamber is reduced. The drive is carried out from the electric motor 10 and the counter-drive 7. The working speed is set using the speed controller of the electric motor.

Calculation of the angle of inclination of the working surfaces of decks

where m is the particle mass, g

V _m - hammer speed, m / s

V _rebound - particle velocity after collision with a hammer, m / s.

соответственно

respectively

The projection of the particle velocity of the grain is determined by the formulas

α is the angle of the reflecting surface of the deck, deg;

a is the distance between the hammers, mm;

δ is the thickness of the hammers, mm;

n is the frequency of rotation of the hammers of the drum, rpm

k is the number of hammer packs.

The proposed device is illustrated by drawings:

In FIG. 1 shows a hammer mill - general view; in FIG. 2 - AA collecting and BB scattering decks; in FIG. 3 - determination of the angle of the working surfaces of the deck; in FIG. 4 is a diagram of an adjustment device.

The technical result when using this crushing scheme is:

- obtaining the finished product with a given grinding module;

- reduction in the amount of dust fraction in the finished product;

- reducing the energy consumption of grinding due to the obtained preliminary deformation and reducing the working speed of the hammer drum.

Claims (2)

1. The method of crushing grain, characterized in that the grinding process is divided into two stages: the first is the damage to the elastic properties of the material, the second is the violation of the plastic properties and the final destruction of the grain. 2. A device for a two-stage grinder of feed grain, including a hopper, a trash bin, a magnetic separator, a shutter, a roller section, a hammer drum, collecting and scattering decks, a counter drive, an electric motor and a frame, characterized in that a roller mill is added to the main working body - the hammer drum section and to increase the likelihood of collision of hammers with defective grains or their particles, the decks are made in the form of scattering and collecting sections.

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