GB2185243A

GB2185243A - A feeding device for a grain dryer

Info

Publication number: GB2185243A
Application number: GB08700019A
Authority: GB
Inventors: Jouko Juhani Alanko
Original assignee: Suomen Sokeri Oy
Current assignee: Suomen Sokeri Oy
Priority date: 1986-01-08
Filing date: 1987-01-02
Publication date: 1987-07-15
Also published as: FI74803C; NO865362L; FI74803B; DK633186D0; SE8605618D0; DE3643719A1; SE8605618L; FI860072A; FI860072A0; DK633186A; GB8700019D0

Abstract

A feeding device for a grain dryer comprises a rotating feeder (2), a slit (A) provided between the feeder and a bottom wall (3); a supporting shaft (6) parallel to the shaft of the feeder and supported by the walls of the grain dryer, one of the bottom wall (3) being fixed to said supporting shaft; an adjusting arm (7) for adjusting the position of the bottom wall (3) and hence the size of the slit; and a spring member (8) which allows the bottom wall (3) to be pivoted temporarily beyond a determined position. Lever (10) can be pivotted about shaft (6) by arm (7), which is pivotted to the lever (10), and this moves lever (9), which is fixed the shaft (6), via the tension in spring (8). The spring allows rotation of bottom wall (3) in the event of an over-size object passing under feeder (2). <IMAGE>

Description

SPECIFICATION A feeding device for a grain dryer The invention relates to feeding devices for particulate material. Devices of the invention may be used with grain dryers.

It is well known that the moisture content of grain should range from 13 to 15 per cent in order that the grain could be stored. On the other hand, it is known that the threshing moisture of grain varies from 20 to 45 per cent. This is why grain dryers are needed.

There are two types of grain dryers provided with a feeding device: a circulating batch dryer and a continuously operated dryer. The circulation batch dryer is first filled with grain, and the grain contained in the dryer is circulated during the drying process in such a manner that the feeding device discharges grain from the dryer and an elevator lifts the grain back into the dryer. In a continuously operated dryer the grain is passed through the dryer once and the feeding device dishcarges dry grain in proportion as the grain gets dry.

It is necessary both in the circulating batch dryer and in the continuously operated dryer that the feeding device discharges grain from the dryer evenly and in controllable amounts.

Besides grain, such products as pea, turnip rape and different kinds of hayseed require drying. In general, each crop type has a dryer of its own, because they have their own requirements both for the dryer and the feeding device. A farmer who grows small amounts of these products has to do with one dryer. The basic idea is that the more fine-grained the product, the smaller the slit between the feeding device and the bottom part.

A widely recognized problem is that stones get amongst the grain during the threshing, e.g. when the crop is flattened. Within the feeding device, such stones damage the feeder and cause unnecessary breaks in the drying process as well as hamper an even feed of the grain.

When the feeder is a rotating roll, the simplest way to protect the feeding device from damage is to fasten a sprocket positioned at the end of the shaft of the roll and connected to driving means on the shaft by means of a cotter which will break before the feeding device is damaged. It is time-consuming to remove the stone which caused the breakage of the cotter and to mount a new cotter. It may also happen that a broken cotter is replaced with a more durable one, with the result that the feeding device possible suffers damage as soon as a stone next gets within it. The slit between the roll and the bottom part cannot be adjusted, but the bottom part can usually be drawn away from under the roll so that obstacies and part of the grain can be removed directly from the hopper of the feeding device. When such a structure is used, each product requires a dryer of its own.

If the slit between the feeder and the bottom part is so large that even the most coarse-grained product can be passed therethrough, a fine-grained product runs through the slit by itself and too rapidly. In order to prevent grain from running through, the bottom part can be made trough-like as is the case e.g. in the feeding device according to German Patent Specification 333,943; it is thereby also possible to enlarge the slit. However, if the slit is enlarged, the feed becomes uneven and hardly controllable. This structure does not, either, prevent disturbances and damages caused by stones or the like, because the position of the bottom and the roll is fixed.

Danish Patent Specification 88,453 discloses a grain dryer in which the feed is carried out between the feeding roll, the nearly vertical wall of the hopper of the feeding device and the bottom part of the feeding device. The opening defined between an extension of the other hopper wall and the bottom part for the flow of the grain can be adjusted. However, the slit between the bottom part and the feeding roll and, on the other hand, between the feeding roll and the hopper wall cannot be varied by adjusting said opening. Consequently, this device does not solve the abovedescribed problems, because the feeding slit itself is fixed, and there are no kind of protective means, except the use of a cotter described above, provided for a situation when a hinder gets into this slit. With this structure, too, each product requires a dryer of its own.

Since the slit defined between the feeder and the bottom part in the prior art devices is fixed in size, only seeds of a certain size can be fed in the desired manner. If the slit is too small, larger seeds are easily damaged.

The feeding device according to the invention provides a decisive improvement with respect to the above drawbacks. For the achievement thereof, the device according to the invention comprises a feeding device for particulate material, the device comprising a hopper for the material, a rotary feeder for producing a discharge flow of material from the hopper over an outflow surface located below the feeder, a slit for the discharge flow being defined between the feeder and the surface, means for selectively adjusting the width of the slit, and means allowing relative movement of the feeder and the outflow surface to take place in the slit-widening direction from a selected adjustment position against resilient means acting to restore the adjustment position.

The invention is advantageous mainly in that it is suitable for both fine-grained and coarsegrained products and that stones or the like do not damage the feeding device or cause breaks in the feeding process.

The structure be simple and reliable in oper ation. The adjustment can be easy to carry out, and the adjusting means of several feeding devices can be interconnected so that the slits of all feeding devices in a grain dryer can be adjusted at the same time. When the biassing force is adjusted to a sufficiently high value, the desired size of the slit can be maintained in spite of the pressure created by the grain column. The hoppers of the feeding device can be emptied rapidly by turning the adjusting means to an extreme position so that the slit is at its largest, and this can be carried out without the use of force.

Other, preferred but optional, features of the invention are specified in claims 2 to 15 of this application.

The invention will be described in the following by means of one preferred embodiment thereof, with reference to the attached drawing, wherein Figure 1 is a partial sectional view of a feeding device seen in the direction of the shaft of the feeding roll, and Figure 2 illustrates the feeding device of Fig.

1 seen in the direction of the arrows A-A.

Fig. 1 shows a feeding device of a grain dryer, a hopper of which feeding device for the grain running from a drying cell of the grain dryer is indicated by means of the reference numeral 1. A supporting shaft 6 is secured between two opposite walls of the grain dryer, of which walls a wall 14 is shown in the figures. A bottom part 3 bent in the form of a wide V is at one end thereof attached unrotatably to said shaft, e.g. by welding or by means of bolts. The supporting shaft 6 is positioned below an outwardly bent edge of a wall 12 of the hopper 1. A feeding roll 2 for feeding grain is positioned below an outwardly bent edge of another hopper wall 13 on the opposite side of the hopper 1, which feeding roll is supported on the walls of the grain dryer similarly as the supporting shaft. The bottom part 3 extends under the feeding roll 2 and slightly beyond it.In the feeding position, that portion of the bottom part 3 which is positioned below the feeding roll 2 is substantially horiziontal or slants slightly towards the hopper 1. A slit A is defined between blades 15 of the feeding roll 2 and the bottom part 3. An interacting whole formed by an adjusting lever 10, a retainer 11, a spring lever 9 and a helical spring 8 is attached to the end of the supporting shaft 6 outside of the wall 14. An adjusting arm 7 is connected to the adjusting lever 10 so that the lever 10 is interconnected with the other adjusting levers by means of the arm 7. The adjusting lever 10 is secured pivotably and the spring lever 9 stationarily on the supporting shaft 6.When the adjusting lever 10 is locked in a determined position, the pivoting of the integral whole formed by the spring lever 9, the supporting shaft 6 and the bottom part 3 is prevented in one direction, i.e. in the direction reducing the slit A, by means of the retainer 11, but allowed temporarily in the opposite direction with respect to the adjusting lever 10 when the force exerted on the bottom part 3 exceeds the elastic constant of the helical spring 8 tightened between the ends of the spring lever 9 and the adjusting lever 10.

Accordingly, the slit A is adjusted by moving the adjusting arm 7 to and fro so that the movement transferred to the adjusting lever 10 also displaces the spring lever 9 and, as a consequence, the bottom part 3, which is supported on the spring lever 9 by means of the supporting shaft 6, as illustrated by means of the arrows in Fig. 1. The spring 8 has the same initial stress in all positions of the adjusting lever 10, because the retainer 11 keeps the adjusting lever 10 and the spring lever 9 at a constant distance from each other.

In the grain dryer, grain runs into the hoppers 1 of the feeding device under the influence of gravity. The bottom part 3 carries the grain column, and the feeding roll 2 discharges grain from the dryer. The bottom part 3 is adjusted to a position suitable for each kind of grain by means of the adjusting arm 7. When a small-grained product is to be fed, the slit A is small and the bottom part 3 is in its extreme slanting position towards the hopper 1, so that the small-grained product stays in place and does not run past the feeding roll 2 as a continuous flow. By correspondingly lowering the bottom part 3, more coarsegrained products can be dishcarged from the dryer without any damage.When a stone contained in the grain is wedged between the blades 15 of the feeding roll 2 and the bottom part 3, the bottom part 3 yields and the stone is passed past the feeding roll 2 without damaging it. The spring 8 returns the bottom part 3 to its predetermined initial position by means of the spring lever 9.

It is to be noted that the invention has been described above only by means of one preferred embodiment thereof. However, it is obvious to one skilled in the art that the invention can be applied and modified in various ways within the scope of protection defined in the attached claims. Accordingly, the spring member, for instance, can be formed by a helical spring attached at the ends thereof to the adjusting means 10 and the supporting shaft 6 and positioned around the end portion of the shaft 6, so that the spring lever can be replaced by a small projection formed on the shaft 6 so as to be supported on the retainer 11 under the influence of the force of the spring. Furthermore, it is possible to position the adjusting means and the spring means at the end of the bottom part 3 on the side of the feeding roll 2 in such a manner, for instance, that the adjusting means is attached to the bottom part 3 by means of a spring so that the adjustment is carried out by altering the vertical position of one end of the spring attached to the adjusting means. Thereby the hoppers 1 may be difficult to get empty instantly. It is also possible to utilize a vertically adjustable, resilient feeding roll 2 which, however, does not provide all the advantages mentioned above.

Claims

1. A feeding device for particulate material, the device comprising a hopper for the material, a rotary feeder for producing a discharge flow of material from the hopper over an outflow surface located below the feeder, a slit for the dishcarge flow being defined between the feeder and the surface, means for selectively adjusting the width of the slit, and means allowing relative movement of the feeder and the outflow surface to take place in the slit-widening direction from a selected adjustment position against resilient means acting to restore the adjustment position.

2. A feeding device according to claim 1, in which the outflow surface is a surface of an outflow member which is movable relative to a frame means of the device.

3. A feeding device according to claim 2, in which the adjustment means comprise a stop, the position of which is selectively adjustable and with which a portion of the outflow member is urged into abutment by the resilient means.

4. A feeding device according to claim 3, in which the resilient means act between the outflow member and a member moveable with the stop.

5. A feeding device according to any of claims 2 to 4, in which the outflow member is mounted in the frame means for pivotal movement about an axis extending parallel to the axis of rotation of the rotary feeder.

6. A feeding device according to claim 5 when dependent on claim 3 or 4, in which the abutment portion of the outflow member is on an arm extending outwardly from the pivot axis of the outflow member.

7. A feeding device according to claim 6, in which the stop is on an arm pivotable about the axis of pivotation of the outflow member and the resilient means act between the pivotable arm and the arm extending outwardly from the pivot axis of the outflow member.

8. A feeding device according to any of claims 2 to 7, in which the rotary feeder is mounted for rotation relative to the frame means about a fixed axis.

9. A feeding device according to any preceding claim, in which the resilient means comprise a mechanical tension spring.

10. A feeding device for a grain dryer, comprising -a rotating feeder for discharging from the grain dryer a granular material running out of a hopper of the feeding device on to a bottom part, a slit being provided between the feeder and the bottom part; -a supporting shaft parallel to the shaft of the feeder and supported by the walls of the grain dryer, one end of the bottom part being supported on the supporting shaft; -an adjusting means for adjusting the position of the bottom part supported by the supporting shaft and, as a consequence, for adjusting the slit; and -a spring member which allows the bottom part to be pivoted temporarily beyond an adjusted position, wherein the adjusting means is arranged pivotally and the spring member stationarily on the end of the supporting shaft mounted non-rotatably on the bottom part, and in which the pivoting of an integral whole formed by the spring member, the supporting shaft and the bottom part is prevented in the direction reducing the slit by means of a retainer positioned in the adjusting means when the adjusting means is locked in an adjusted position, but allowed temporarily in the opposite direction with respect to the adjusting means when the force exerted on the bottom part exceeds the force resisting the yielding of the spring member.

11. A feeding device according to claim 10, in which the spring member comprises a spring lever and a spring which is tightened between the ends of the spring lever and the lever-like adjusting means.

12. A feeding device according to claim 11, in which an adjusting arm is attached to the lever-like adjusting means for inter-connecting several adjusting means.

13. A feeding device according to any of claims 10 to 12, in which the spring is a helical spring.

14. A feeding device substantially as hereinbefore described with reference to the drawings.

15. A grain dryer incorporating a feeding device according to any preceding claim.