GB2302075A

GB2302075A - Pneumatic conveyor system

Info

Publication number: GB2302075A
Application number: GB9511892A
Authority: GB
Inventors: Alfred John Bailey
Original assignee: GREENLAND UK Ltd
Current assignee: GREENLAND UK Ltd
Priority date: 1995-06-12
Filing date: 1995-06-12
Publication date: 1997-01-08
Anticipated expiration: 2015-06-12
Also published as: GB9511892D0; GB2302075B

Abstract

A conveying system for granular material consists of a tank 1 for receiving and storing the granular material and preferably carried on the front of a vehicle, an ejector pump 2 remote from the tank, an air feed conduit 5 leading to the ejector pump 2 and a passage 7 arranged to connect the tank 1 and the feed conduit 5 so that granular material might pass from the tank 1 to the conduit 5 and be carried by entraining air to and through the ejector pump 2, and a delivery conduit 11 leading from the ejector pump 2 to second tank 4 at the rear of the vehicle to receive entrained granular material. The level of material in the second tank 4 is regulated by a sensor 15 which operates to open and close a valve 16 in the feed air conduit 5. Granular material from the second tank 4 may be metered and fed by pressurised air surplus to the requirements of the ejector to ground engaging coulters 18 also mounted on the vehicle.

Description

CONVEYOR SYSTEM FOR GRANULAR MATERIAL The present invention relates to conveyor systems for granular material and particularly for grain or granular fertiliser carried on and dispensed by agricultural vehicles.

Hitherto in recent years grain seeding and fertilising of soil by granular fertiliser has been carried out by using agricultural tractors either to pull wheeled seed/fertiliser drills or to carry them. Drilling systems carried on tractors are known as 'mounted' systems. These have the advantage in that they are more manoeverable than pulled drills but have the disadvantage that they cannot carry as much. The reason for this is that the storage tank for the granular material is carried in an overhung position behind the rear wheels of the tractor thus creating an increase in the load carried by the rear wheels. Even though the rear wheels may have a large 'footprint' the loads may still be such as to cause serious compaction of the ground and so the size of the tank must be limited.It is also possible that the size of the overhung load may be limited but the lifting capacity of the lifting arrangement on the tractor.It is known that carrying the storage tank at a position ahead of the front wheels of the tractor will spread the total load more uniformly between the front and rear wheels and as the front wheel track is often narrower than that of the rear wheels the damage to the ground by compaction is considerably reduced thus permitting an increase in the tank size without compromising manoeverability. However the granular material has to be moved from the front tank to the drills situated at the rear.

The present invention aims to provide a robust and economical conveying system for this purpose among others.

According to the present invention there is provided a conveying system for granular material comprising a tank for receiving and storing the granular material, an ejector pump separated therefrom, an air feed conduit leading to the ejector pump and a restrictable passage arranged to connect the tank and the feed conduit so that granular material might pass from the former to the latter and a delivery conduit leading from the ejector pump to a destination thereby enabling feed air and entrained granular material from the tank to be transferred to the destination.

Preferably the conveying system is adapted to be mounted on and driven by the auxiliary power source on an agricultural tractor, the destination in such a case being one or more soil engaging coulters of a drilling machine.

As a further preference the destination may be a second tank having a level sensor for material contained within it, signals emitted from such a sensor being received by valve apparatus adapted to restrict or stop flow of granular material through the feed conduit. When such a conveying system is mounted on an agricultural tractor the ground engaging coulters will constitute a further destination. for the granular material. In such a case the fan for operating the ejector pump would also be driven from the auxiliary power source on the tractor and air surplus to the requirements of the ejector pump would be used to convey a metered flow of granular material from the second tank to the ground engaging coulters.

According also to the present invention a method of providing a supply of granular material to a ground engageable coulter carried on a vehicle comprises the steps of supporting a first tank at the front of the vehicle, supporting a second tank in the vicinity of the ground engaging coulters, both tanks being capable of receiving and storing granular material, and conveying such granular material from the first tank to the second by means of an ejector pump and further conveying said material from the second tank to the coulters by pneumatic means.

Preferably the method includes the step of so regulating the level of the material in the second tank as not to exceed a predetermined value by inhibiting the ability of the ejector pump to convey the material. The step of inhibiting the conveyance of material may consist in arranging for an opening in the first tank to deposit a limited amount of granular material in the ejector feed conduit such amount to be sufficiently large to block said opening and sufficiently small to be moved by the action of the ejector pump. The deposit may occur at the lowest point of a Vee shaped bend in the feed conduit.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows the general disposition of the parts of the conveyor system in relation to each other, Figure 2 shows the disposition of the conveyor system in relation to an agricultural tractor on which it may be mounted.

Figure 3 is a view of a version of the first tank shown in figure 1 Figure 4 is a detail view of a part of the feed conduit Referring to Figure 1 the conveyor system comprises a first tank 1, an ejector pump 2, a fan 3 and a second tank 4. Both tanks are shown as hopper and the first being apparently larger than the second. It is to be understood that they may be of any practical shape or volume. A feed pipe 5 having an inlet 6 passes under the first tank 1 and is connected to it by a restricted passage 7. Feed pipe 5 terminates in a nozzle or outlet 8 situated within the plenum chamber 9 of the ejector pump 2 and is aligned with the opening 10 of a delivery pipe 11 the two being spaced apart. The outlet 12 of the delivery pipe is located within the second tank 4. The fan 3 is driven by a shaft 13 and delivers air to the plenum chamber 9 through a flexible tube 14.

The second tank 4 is equipped with a level sensor 15 for the granular material and operates to cause a valve 16 placed at or near to the base of the first tank to close and open when needed to interrupt the flow of granular material. The dotted line 20 represents the electrical control over valve 16 Outflow from the second tank may be routed to any destination but in the case of the illustration shown in figure 1 the material passes to a series of metering units 17 which control the flow and, with the aid of an airstream, is delivered to the hollow ground engaging coulters 18 of an agricultural drill through flexible pipes 19. The pressurised air for the airstream is derived from the plenum chamber 9 of the ejector pump 2 through a pipe 20.

In operation the first tank 1 is filled with granular material which may be seeds or granular fertiliser when the conveyor system is used with an agricultural drill and the fan is started to pressurise the plenum chamber and develop suction in the feed pipe 5. The second tank being assumed to be empty and the valve 16 open, air entering the feed pipe 5 at inlet 6 as a result of suction will entrain granular material and pass it to the opening 10 of the delivery pipe for onward transmittal to the second tank 4. When the level there reaches the predetermined height at which the sensor is activated the latter closes the valve 16 and stops the flow of granular material meantime the air provided by the fan via pipe 20 is still operative to transmit metered material from the metering units to the coulters through pipe 19.

Figure 2 shows the main elements of the conveyor system mounted in an agricultural tractor 21. The elements carry the same reference numerals as appear in figure 1. The wheels 22 and 23 of the tractor are shown in ghosted form. The fan 3 and ejector pump 2 together with the second tank 4 are mounted on a frame 24 itself mounted on the power lift links 25 and 26 of the tractor and the fan is driven from the tractor power take off 26. As can be seen the placement of the larger first tank at the front of the tractor enables there to be a better weight distribution between the wheels and the possibility of a reduced size of second tank 4 leading to better manouverability and less ground compaction.

Figure 3 shows the view from the front of a first tank 1 which might have two outlets 27 and 28 which might each be served by its own ejector pump delivering to separated locations on a single secondary tank or to two secondary tanks. The possibility of carrying both seed and granular fertiliser and of dispensing both to coulters clearly exists.

Figure 4 is an enlarged cross section through the lower part of the first tank 1 and shows the inverted bend 30 in the feed pipe 5 in the vicinity of the restricted passage 7. The purpose of this arrangement is to ensure that, when the sensor 15 causes the valve 16 to close, the amount of material which drops out of the first tank will build up rapidly and seal the passage, but will not be of such a mass as to prevent the suction created by the ejector pump from moving it along the pipe 5 when the valve 16 open again. The benefit of this arrangement is that the valve 16 can work in air and not in the granular material where a much stronger and expensive construction of valve would be needed.

The conveyor system shown in figure 2 may be dismounted from the tractor very readily especially if the tractor is equipped with a power lift at the front. Also the possibility exists in the case of a vehicle having space between the front and rear wheels of mounting the first tank in this position.

Claims

1. A conveying system for granular material comprising a tank for receiving and storing the granular material, an ejector pump separated therefrom, an air feed conduit leading to the ejector pump and a passage arranged to connect the tank and the feed conduit so that granular material might pass from the former to the latter and a delivery conduit leading from the ejector pump to a destination thereby enabling feed air and entrained granular material from the tank to be transferred to the destination.

2. A conveying system as claimed in claim 1 which is adapted to be mounted on and driven by the auxiliary power source on an agricultural tractor, the destination in such a case being one or more soil engaging coulters of a drilling machine.

3, A conveying system as claimed in claim 1 wherein the destination is a second tank having a level sensor for material contained within it, signals emitted from such a sensor being received by valve apparatus adapted to restrict or stop flow of granular material through the feed conduit.

4. A conveying system as claimed in claim 3 and in the case when such a conveying system is mounted on an agricultural tractor the ground engaging coulters will constitute a further destination for the granular material.

5. A conveying system as claimed in claim 3 wherein the fan for operating the ejector pump is also driven from the auxiliary power source on the tractor.

6. A conveying system as claimed in claim 4 wherein air surplus to the requirements of the ejector pump is used to convey a metered flow of granular material from the second tank to the ground engaging coulters.

7. A conveying system as claimed in claim 1 wherein a feed chamber, open to atmosphere, is positioned at the bottom of the tank to receive granular material by natural flow to a natural level and the entry of the air feed conduit is adjustable to below this level in order that air sucked into the air feed conduit shall entrain granular material during operation.

8. A method of providing a supply of granular material to a ground engageable coulter carried on a vehicle comprises the steps of supporting a first tank forward of the rear wheel, supporting a second tank in the vicinity of the ground engaging coulters, both tanks being capable of receiving and storing granular material, and conveying such granular material from the first tank to the second by means of a feed conduit leading to an ejector pump and further conveying said material from the second tank to the coulters by pneumatic means.

9. The method according to claim 7 including the step of so regulating the level of the material in the second tank as not to exceed a predetermined value by inhibiting the ability of the ejector pump to convey the material.

10. The method according to claim 8 wherein the step of inhibiting the conveyance of material consists in providing a valve in the ejector feed conduit capable of closing said conduit.

11. The method according to any one of claims 7,8 or 9 including the step of arranging for an opening in the first tank to deposit a limited amount of granular material in the ejector feed conduit such amount to be sufficiently large to block said opening and sufficiently small to be moved by the suction of the ejector pump.

12. The method according to claim 8 wherein the step of depositing a limited amount of granular material consists in arranging for the deposit to occur at the lowest point of a Vee shaped bend in the feed conduit.

13. The method according to any one of claims 7,8 or 9 including the step of arranging an open topped feed chamber at the bottom of the first tank to receive and contain granular material which naturally flows into it therefrom and the further step of locating the intake at an appropriate level below the surface of the granular material so that the air sucked into the feed pipe will entrain granular material with it.

14. A conveying system for granular material substantially as described herein with reference to the accompanying drawings.

Amendments to the claims have been filed as follows 1. A conveying system for granular material which is adapted to be mounted on and driven by the auxiliary power source on an agricultural tractor,comprising a tank for receiving and storing the granular material, an ejector pump separated therefrom, an air feed conduit leading to the ejector pump and a passage arranged to connect the tank and the feed conduit so that granular material might pass from the former to the latter and a delivery conduit leading from the ejector pump to a destination thereby enabling feed air and entrained granular material from the tank to be transferred to the destination.

2. A conveying system as claimed in claim 1 in which the destination is one or more soil engaging coulters of a drilling machine.

4. A conveying system as claimed in claim 3 in which the ground engaging coulters constitute a further destination for the granular material.

5. A conveying system as claimed in claim 3 wherein the fan for supplying the air feed is also driven from the auxiliary power source on the tractor.

9. The method according to claim 8 including the step of so regulating the level of the material in the second tank as not to exceed a predetermined value by inhibiting the ability of the ejector pump to convey the material.