GB1571678A - Grain separator - Google Patents

Description

(54) GRAIN SEPARATOR (71) We, SATAKE ENGINEERING CO.

Lam., a corporation organised under the laws of Japan, of 19-10, Ueno-l-chome, Taito-ku, Tokyo, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a grain separator which uses a cylindrical perforated wall for the separation of grainy material from jill- purities.

In separating grainy materials from impurities such as longer chaff, broken stems, bits of cords, and fibrous matter by means of a perforated plate, separators have been employed which either vibrate a fiat perforated plate or revolve a cylindrical perforated plate to allow the normal grains alone to pass through the perforations. In either case the perforated surface of the plate is directly subjected to the weight of the grains, and the surrounding edges of the perforations provide resistance to the flow of the grains pass- ing over them.Consequently, the mass of grains moving over the perforations tends to form a dense, concentrated flow, Grains practically comparable lin size to the perforations, once caught by the perforations, will be forced deeper into them under the weight of the mass. The grains will not easily come away even if urged outward from the rear side of the perforated plate by a brush or the like. Thus, the separators using the perforated plates of the types described have a common disadvantage of reduction in separation efficiency due to frequent clogging of the perforations during operation.

The present invention has been arrived at in an effort to acheive a separator which eliminates the foregoing disadvantage of the existing separators and maintains stable separation performance.

According to the present invention, there is provided a grain separator including a hol- low cylinder with a perforated wall mounted to rotate about its axis which is horizontal or at a slight angle to the horizontaI, means for rotating said cylinder, means located at one end of said cylinder to feed thereinto a grainy material Ito be separated, and discharge means located at the other end of said cylinder, characterized in that said cylinder comprises a cylindrical wall formed in to a number of folds with inwardly projecting ridges extendiing in parallel and su stantaaily folds that lead in the direction of rotation axially of said cylinder, and the faces of said are unperforated, whereas the trailing faces on the opposite sides of said ridges are form- ed with perforations.

When the cylinder of the construction embodying the invention is revolved and a grainy material containing impurities to be separated out is fed to it, the force resulting from a combination of the gravity indue to weight d the material and the force imparted ;by the revolution of the cylinder is applied solely to the leading faces of the folds of the cylinder.The opposite, perforated faces that follow are subjected only to the force of gravity since they face oppositely to the direction of rotation of the cylinder, and, because of the inertia of the material, not all of the gravity act. The material now flows in the form of a loose mass, Idue to less resistance caused by the surrounding edges of the perforations. The grains finer than ;the perforations are passed with weak force through the perforations to the outside of the cylinder. The impurities are left inside the cylinder for further separation.The grain about the size of the peforations, even if lodged in the perforations, will be insecure and will come away almost completely by gravity as the perforations dse upward with the revolution of the cylinder. Complete removal of the remaining entrapped grains can be ensured by the provision, adjacent to the cylinder, of a brush Or the like which will pat and move in sliding contact with the outer surface of the cylinder. Thus, with no pos sibility of clogging, the separator of the invention stably maintains its separation per- formance.

In practice of the invention, the per forations in the trailing faces of the folds may be square, circular, elliptical or of other su table contour, depending on the kind of grainy material to be handled. Also, the cylinder need not be round in cross section; when desired, it may be polygonal instead.

The brush for patting and moving in sliding contact with the outer surface of the cylinder may be supplanted by various devices, such as a flexible muiti-bladed patting wheel to be described below in connection with an embodiment of the invention.

The invention will now he described in more detail with reference to the accompanying drawings of a preferred embodiment.

In the drawings: Figure 1 shows a separator in vertical section, and Figure 2 shows a perspective view of the cylinder and patting wheel of the separator of Figure 1.

Preferring to Fig. 1, a housing 1 contains a hollow open-ended cylinder 2 slightly in dined from the horirontal. The end portions of Ithe cylinder are provided with annular loops or rails 3, 4, which engage two pairs of rollers 5,6 disposed, in spaced relation and across the axis of the cylinder, on the bot- tom of the housing. The cylinder is thus revolvably supported by these rollers. On the bottom of the housing is also mounted an electric motor 7, whose pulley 8 is connected to a pulley 9 on one end of the cylinder by an endless belt 10, so that the cylinder can revolve in the direction indicated ;by an arrow A in Fig. 2.

As shown in Figs. I and 2, the body of the cylinder 2 consists of a cylindrical wall 12, most of which is formed into folds, in zigzag pattern, with the inner ridges 11 extending in parallel axially of the cylinder. On the two flanks or faces of each fold as separated by the inner ridge 11, the face 1,3 leading in the direction A of revolution of the cylinder is solid and hopeless, whereas the trailing face 14 is formed with a number of perforations 15.

Turning to Fig. il, the sylinder 2 is associa ted at one end with a screw conveyor unit 17, the opposite end of which is communicated with the lower part of a hopper 16 extended Ithrough, and secured to, the top wall of the housing. The conveyor unit comprises a housing 18, a screw conveyor 19, a pulley 20 for driving the conveyor, and an opening 21 formed in the housing to feed the material to be separated into the cylinder. At the other end of the cylinder is provided a discharging trough 22 which extends through the corresponding end wall of the housing to the outside.Adjacent to, and in parallel with, the outer periphery of the cylinder 2, a rotary paddle wheel with flexible blades 23 is rotatably supported by bearings 24, 25, which in turn are fixed to the underside of the top wall ,of the housing.

In the operation of the apparatus, the cylinder 2 is revolved dn 'the direction A by the motor 7, the screw conveyor 19 is driven, and the unclean material to be separated is fed from the hopper 16 to one end portion of the space inside the cylinder through the feed opening 21. Thus, in the manner already described, the force that results from the combination of gravity due to the weight of the material itself and the force produced by the revolution of the cylinder acts upon the leading faces 13. The trailing faces 14 with the perforations are subject oniy to gravity since they face opposite to the direction of the revolution of the cylinder, and not all of the gravity acts since it is partly counteracted by the inertia of the material.The material, now in the form of a loose mass, is tumbled inside the revolving cylinder.

While fine grains smaller in diameter than the .perforations are weakly forced out through the holes 15 onto lithe bottom of the housing, the remaining mass is gradually transferred to the opposite end of the cylinder with the rotation of the latter, until it is discharged through the trough 22 to the outside of the housing. The material that has passed through the perforations is taken out of the housing via suitable collector means (not shown).The grains substantially as large in diameter as the perforations if caught by and lodged in the latter, will not be secure in pos- ition and will mostly come away gravita- jtionally as the cylinder portion having the perforations in which the grains are lodged rises upward with the revolution of the cylinder. The rest of the grains entrapped are forced out completely from the perforations' by the action of the rotary paddle wheel the flexible blades 23 of which both pat and turn in sliding contact with the ,outer surfaces of the folds of the cylinder wall 12 as the cylinder and paddle wheel rotate.Thus, the possibility of separation efficiency drop due to clogging as has usually been the case with the existing equipment is ,totally precluded Although the cylinder in the embodiment so far described is mounted with some inclination to the horizontal, this inclination is not essential. The cylinder may be installed to rotate on a horizontal axis instead, in which case again Ithe material inside the revolving cylinder is urged to the advancing or ascending side of the bottom and is gradually scattered and shifted axially of the cylinder toward its discharge end. To facilitate the axial movement of the material, the folds of the cylinder wall 12 may be gently helically curved rather than being straight in parallel with the axis d;the cylinder, or such helical folds may be combined with inclination of the cylinder. For practical purposes the mere inclination of the cylinder as dn the embodiment described above is most desirable.

WHAT WE CLAIM IS:- 1. A grain separator including a hollow cylinder with a perforated wall mounted to rotate about its axis which is horizontal or at a slight angle to the horizontal, means for rotating said cylinder, means located at one end of said cylinder to feed thereinto a grainy material to be separated, and discharge means located at the other end of said cylinder, characterized in that said cylinder comprises a cylindrical wall formed into a number of folds with inwardly projecting ridges extending in parallel and substantially axially of said cylinder, and the faces of said folds that lead in the direction of rotation are unperforated, whereas the trailing faces on the opposite sides of said ridges are form ed with perforations.

2. A grain separator according to claim 1 wherein there is disposed externally along side the cylinder rotary flexible patting means having elements for patting, and turning in sliding contact with, the outer surfaces of the folds in the cylinder wall.

3. A grain separator according to claim 1 or claim 2, wherein the ridges of the folds into which the cylindrical wall is formed are gently helically curved with respect to the axis of the cylinder.

4. A grain separator substantially as des cabled with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. as dn the embodiment described above is most desirable. WHAT WE CLAIM IS:-

1. A grain separator including a hollow cylinder with a perforated wall mounted to rotate about its axis which is horizontal or at a slight angle to the horizontal, means for rotating said cylinder, means located at one end of said cylinder to feed thereinto a grainy material to be separated, and discharge means located at the other end of said cylinder, characterized in that said cylinder comprises a cylindrical wall formed into a number of folds with inwardly projecting ridges extending in parallel and substantially axially of said cylinder, and the faces of said folds that lead in the direction of rotation are unperforated, whereas the trailing faces on the opposite sides of said ridges are form ed with perforations.

2. A grain separator according to claim 1 wherein there is disposed externally along side the cylinder rotary flexible patting means having elements for patting, and turning in sliding contact with, the outer surfaces of the folds in the cylinder wall.

3. A grain separator according to claim 1 or claim 2, wherein the ridges of the folds into which the cylindrical wall is formed are gently helically curved with respect to the axis of the cylinder.

4. A grain separator substantially as des cabled with reference to the accompanying drawings.