GB2067499A

GB2067499A - Pneumatic extraction apparatus

Info

Publication number: GB2067499A
Application number: GB8039908A
Authority: GB
Original assignee: Engelbrecht & Lemmerbrock; Engelbrecht and Lemmerbrock GmbH and Co
Current assignee: Engelbrecht & Lemmerbrock; Engelbrecht and Lemmerbrock GmbH and Co
Priority date: 1979-12-15
Filing date: 1980-12-12
Publication date: 1981-07-30
Also published as: IT8026651A0; NO157601C; DE2950662C2; IT1134727B; GB2067499B; DE2950662A1; FR2473478A1; FR2473478B1; NL8006530A; SE8008679L; NO157601B; NO803761L; CH653311A5; SE449089B; ATA580380A; AT384597B

Abstract

This invention relates to pneumatic extraction apparatus comprising a suction duct 1 connected to a suction blower 7 for extraction of agricultural stalk or leaf materials from a silo and for conveying the same to a feeding station for cattle. The suction duct 1 has interposed in it a container 2 subdivided by a horizontal sieve 3, the suction pipe for infeed of the material leading into a chamber 5, situated below the sieve 3 and shut off by means of floor flaps 8, 9, held shut by counterweights 11 and a chamber 4 located above the sieve 8 connected to the suction blower 7. The suction duct 1 may be shut off or the blower 7 switched off allowing the floor flaps 8, 9, to open as a result of the weight of the material present in the lower chamber 5. <IMAGE>

Description

SPECIFICATION Pneumatic extraction apparatus The invention relatesto pneumatic apparatus for extracting and conveying dry blade or leaf materials or silage from a silo or store by means of a suction head connected to a suction fan.

Pneumatic extraction apparatus hitherto known for conveying materials of the aforesaid nature operate by feeding the material present in a silo or store to a suction head of a duct leading to the blower, the material then passing through the blower and being conveyed at the pressure end to a place of consumption, e.g. a cow shed. In many cases, the materials conveyed consist of dry stalk or leaf materials, e.g. lucerne, clover or the like, the leaf components of which are comminuted considerably during traversal through the blower, so that a con siderabie proportion of the material is fed to the fodder passage of a cow shed in a condition in which it cannot be picked up by the cattle. Apart from this, the delivery of the material conveyed by compressed air into a cow shed results in excessive air displacement harmful to the health of the animals.

It is an object of the invention to prevent or minimise powerful displacements of conveying air within cow sheds or other consumer locations and at the same time to deal with dry stalk and leaf materials very carefully without comminution.

Accordingly, the invention consists in apparatus for pneumatically extracting and conveying dry blade or leaf materials or silage from a silo or store by means of a suction head connected to a suction blower, wherein a suction duct of the blower has interposed in it a container subdivided by a sieve, said container having a first chamber situated above the sieve which can be placed under a cancellable negative pressure via a connector pipe leading to said blower, and a second chamber situated below said sleeve, arranged to be supplied with conveyed material by the negative pressure and wherein said second chamber has a floor comprising at least one downwardly pivotable flap which is held in the closed position by a counterweight and opens under the weight of the material supplied when the negative pressure is cancelled.

The material conveyed is thus carried by means of negative pressure into the container chamber below the dividing sieve and the conveying air flows to the blower and from the latter into the ambient atmosphere, so that no appreciable air displacements can occur if the container separating the material conveyed is placed within a closed space, e.g. within a cow shed. The material conveyed consequently does not come into contact with revolving parts of the blower in any event, meaning that it arrives in practically undamaged form and without crumbling in the container chamber below the sieve, from which it is removed by dropping downwards as soon as the negative pressure within the chamber above the sieve is neutralised.

In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings which illustrate two embodiments thereof by way of example and in which: Figure 1 shows a diagrammatical axial section through an upright receiving container for conveyed material, with a suction blower connected thereto.

Figure 2 shows a diagrammatical longitudinal cross-section through horizontal receiving containers with a suction blower connected thereto, and Figure 3 shows a cross-section through one of the two horizontal containers according to Figure 2.

Referring now to the drawings and firstly to Figure 1, the apparatus there depicted is intended to extract silage material, primarily dry stalk or blade materials, pneumatically from a silo or store, and to feed the same to a consumer location e.g. a cow shed, without the possibility of causing powerful air displacements or subjecting the dry material to damage or comminution within the shed whilst doing so.

In this figure, the material present in the silo, for example a high-rise silo, is fed to a pneumatic suction head and is conveyed into a container 2, advantageously in tangential direction, via a suction duct and a connecting duct 1. This container 2, situated above a feeding passage in a cow shed for example is subdivided by a sieve 3 into two chambers 4 and 5, the first or upper chamber4 being connected via a duct 6 to a suction blower 7 the pressure end of which leads to the ambient atmosphere.

The second or lower chamber 5 advantageously comprises mutually superposed interconnectible annular elements madeto correspond in number two the capacity of the chamber 5 required in each case.

The base of the container comprises at least one and preferably two hinged flaps 8, 9 the combined area of which is a little greater than the cross-section of the container 2, so that the bottom edge of the container2 forms a stop for the upwardly pivoted flaps 8 and 9 which are connected via hinger 10 to the container 2 and pivoted into the closed position by counterweights 11. The container 2 is placed under negative pressure as soon as the blower 7 is switched on, so that the flaps 8,9 are pressed hermetically against the lower edge of the container and are thus able to bear an appropriate selected weight of the material conveyed. Conveyed material is then drawn by negative pressure from the silo or store into the lower container chamber 5 until the required quantity of material is obtained within the space 5.A throttle valve 12 is then closed wholly or partially either manually or mechanically within the duct 6, thereby cancelling the negative pressure within the container 2, so that the weight of material supplied may then pivot the flaps 8 and 9 downwards into the position shown dash-dotted, so that the conveyed material drops without hindrance, e.g. on to a feeding line, and may be picked up by the cattle.

The container 2 illustrated in Figure 1 may also be made in horizontal form and of optional length, e.g.

corresponding to the length of a feeding line, as illustrated in Figure 2.

In this case, conveyed material coming from a silo or from the floor of a store is fed to a horizontal container 2a via the duct 1 at one end thereof into the lower chamber 5a of the container 2a divided by the horizontal sieve 3a, by the fact that the upper con tainer chamber 4a is connected - at the other end of the container-to the suction duct 6 leading to the blower 7. The upper container chamber 4a is sub divided at appropriate intervals by suspended flaps 13, and in correspondance with this subdivision, the container 2a is provided with floor flaps 14 which are held in their closed position by counterweights 15 similar two those referred to with reference to Figure 1. The conveyed material is first fed to the end of the lower chamber 5a.When the charge reaches the point occupied by the first suspended flap 13a, this flap is pivoted by the conveying airflow denoted by dash-dotted lines into the dash-dotted position, so that the lower chamber 5a is then filled gradually.

As soon as the charge reaches the point occupied by the last flap 13c, the pivotal displacement of this flap 13c actuates a switch 16a which deactivates the blower 7 or closes a constrictor in the duct 6. This cancels the negative pressure within the container 2a and the weight of the conveyed material present in the chamber 5a presses the flaps 14 downwards, so that the material may drop downwards onto the feeding line in the shed.

In the embodiment described with reference to Figure 2, a container2b may be connected in parallel to the container 2a, e.g. for a second feeding line, and the conveying duct section 1 may then be connected via a switch 17 to the lower chamber Se of the container 2a orto a lower chamber Sb of the container 2b.

If, for example, the chamber 5a of the container 2a has been filled with conveyed material, the last sus pended flap 1 3c activates a switch 1 6b which then lies in a circuit reversing the switch 17 to allow of charging the chamber 5b of the container 2 with conveyed material. When the chamber 5b has been filled with material, a switch 1 6b is actuated again by the last suspended flap 13c for reversing the switch 17, and if applicable the blower7 is switched off at the same time or a throttle valve is closed within the duct 6, thereby cancelling the negative pressure in both containers 2a and 2b, and the container chambers 5a and 5b emptying via the then downwardly pivoting floor flaps 14a and 14b.

Claims

1. Apparatus for pneumatically extracting and conveying dry blade or leaf materials or silage from a silo or store by means of a suction head connected to a suction blower, wherein a suction duct of the blower has interposed in it a container subdivided by a sieve, said container having a first chamber situ ated above the sieve which can be placed under a cancellable negative pressure via a connector pipe leading to said blower, and a second chamber situ ated below said sieve, arranged to be supplied with conveyed material by the negative pressure and wherein said second chamber has a floor comprising at least one downwardly pivotable flap which is held in the closed position by a counterweight and opens under the weight of the material supplied when the negative pressure is cancelled.

2. Apparatus as claimed in claim 1, wherein a closing restrictor is incorporated in the suction duct leading to the blower from the first container chamber which is located above the second chamber.

3. Apparatus as claimed in claim 2, wherein the restrictor is manually or mechanically operable.

4. Apparatus as claimed in claim 2 or 3, wherein the subdivided container has a circular cross-section and below the sieve comprises annular segments which may be connected one above another, the lowest ring carrying a hinge or hinges of the floor flaps the combined area of which is greater than that of the base area ofthe container and wherein the bottom edge of the container forms a stop for said flaps in their closed position.

5. Apparatus as claimed in claim 1, wherein the container has an elongated horizontal form and is subdivided in the longitudinal direction by a horizontal sieve, the first chamber being situated above the sieve and connected tithe suction side of the blower and being subdivided by suspended flaps which are deflectible in the direction of the blower, and the second chamber being situated below the sieve and comprising closable floor flaps corresponding to the mutual spacing of said suspended flaps and openable by cancellation ofthe negative pressure within the container.

6. Apparatus as claimed in claim 5, wherein the flap farthest from the blower and suspended above the sieve within the upper chamber co-operates with a switch which deactivates the entrainment of the blower or closes a restrictor in the suction duct between the blower and the container.

7. Apparatus as claimed in claim 5 or 6, wherein the container is subdivided into two elongated con tainers connected in parallel, the two upper chambers situated above their respective dividing sieves having an extremity connected to the suction side of the blower and the two lower chambers situated below their respective sieves being chargable at will with conveyed material via a switch at the other end.

8. Apparatus as claimed in claim 7, wherein the switch is arranged to c-operate for reversing purposes with two contactors which co-operate, within the upper chambers ofthetwo containers, with the suspended flaps which are the farthest from the blower.

9. Pneumatic extraction apparatus, substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

10. Pneumatic extraction apparatus, substantially as hereinbefore described with reference to Figures 2 and 3 of the accompanying drawings.