DE2720527A1 - METHOD OF GRINDING GRAIN - Google Patents

Description

PATc [NTANWAIJE

Quantity υ Frahl

Erhardtstrasse 12. D-8000 Munich 5

272C527

Patent Attorneys Menges & Prahl, Erhardtstr 12, D-8000 Munich 5

Graduate engineer Rolf Menges Dipl-Chem Dr Horst Prahl

Telephone (089) 26 3847 Telex 529581 BIPATd Telegram BIPAT Munich

Your reference / Your ref Our reference / Our ref Datum / Date

P 175

May 6, 1977

Simon-Barron Ltd.
Gloucester, England

Method of grinding grain

The invention relates to the grinding of grain using a hammer mill, which means a mill with a grinding chamber to which a sieve for the passage of ground material is assigned and in which rotating hammers are arranged which grind the ground material supplied to the chamber.

The Applicant in has observed that grain which is in a hara

709849 / 07A7

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mermühle is entered, within the grinding chamber aufqrund of blows it receives from the hammers before whirling around it is pulverized and exits the mill. Observations suggest that this phenomenon is at least partially is due to the aerodynamic shape of the grain.

The invention provides an improvement in the efficiency of grinding grain in a hammer mill by the Grain is subjected to a pretreatment aimed at destroying the streamlined shape of the same.

A method for grinding grain in a hammer mill of the type mentioned at the beginning is therefore characterized according to the invention characterized in that the grain is first crushed before it is fed to the mill.

Further refinements and advantages of the invention emerge from the following description of exemplary embodiments of the method according to the invention.

The grain to be ground is first passed through the gap between at least two steel rollers, whereby it is comminuted will. This crushing has two important effects.

First, the crushing creates the streamlined shape of the grain, thereby reducing the tendency of the grain to whirl around within the mill when it is yours

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is then fed.

Second, the crushing causes the hard outer skin to be broken, thereby reducing the impact force which is required in the mill to grind the grain into particles of a certain size.

The applicant has found that there is an optimal gap setting for the steel rollers during the comminution process and that this gap setting is dependent on the mean minimum dimension of the grain to be comminuted. It has been shown, for example, that the gap setting should be 25 o of the mean minimum dimension of barley grains and 75 % of the mean minimum dimension of wheat and maize kernels. If the average minimum dimensions of barley, wheat and maize are assumed to be 3 mm, 3 mm or 5 mm, the gap setting during the shredding process should be 0.75 mm, 2.25 mm or 3.75 mm.

After the grain has been crushed, it is fed to the hammer mill for normal milling.

It has been found that wheat kernels can be milled to a certain degree with a total energy saving of the order of 20 % by using the pre-shredding step. Thus, for the same input power, a higher throughput can be achieved in comparison with the conventional milling process, in which no pre-comminution takes place .

709849/0747

Claims (5)

PATENT CLAIMS; \ l) Method for grinding grain in a hammer mill, characterized in that the grain is first crushed before it is fed to the mine. 2. The method according to claim 1, characterized in that the grain is crushed by passing it through the gap between two rollers. 3. The method according to claim 2, characterized in that the grain to be crushed is barley and that the gap between the V. 'salts is set to 0.75 mm or about this value. 4. The method according to claim 2, characterized in that the grain to be crushed is wheat and that the gap between the rollers is set to 2.25 mm or about this value. 709849/0747
ORIGINAL INSPECTED 27; ··· ^ 77 5. The method according to claim 2, characterized in that the grain to be crushed is corn and that the gap between the rollers is set to 3.75 mm or about this value. 709849/0747
ORIGINAL INSPECTED