GB2181719A

GB2181719A - A device and method for dislodging material from the walls of storage vessels

Info

Publication number: GB2181719A
Application number: GB08524920A
Authority: GB
Inventors: Shlomo Anteby
Original assignee: IFINCORP ANTEBY SYSTEMS INTERN
Current assignee: IFINCORP ANTEBY SYSTEMS INTERN
Priority date: 1985-10-09
Filing date: 1985-10-09
Publication date: 1987-04-29
Also published as: WO1987002337A1; AU6476486A; GB8524920D0; EP0241503A1

Abstract

A device for dislodging stored material from the walls of storage vessels, such as silos, the device comprising: a main structure having a leading end; means coupled to the main structure for suspending the device inside the storage vessel in substantially horizontal alignment with the material to be dislodged, the leading end being nearer this material; a pair of arms movable attached to said leading end for movement in opposition towards and away from one another; actuator means coupled to the main structure and to the arms for causing said movement of the arms; and air supply means having outlets attached to the arms for directing compressed air at the material as the arms move thereby to dislodge the material randomly as the suspending means is used to direct the device towards the remaining material.

Description

SPECIFICATION A device and method for dislodging material from the walls of storage vessels This invention relates to apparatus for dislodging materials supported by the walls of storage vessels such as silos so thatthe material will fall to the bottom of the vessel where it is to be removed. More particuiarly, the invention relates to apparatus for dislodging stored material which has accumulated on the inside walls of such vessels.

Bulk materials are often stored in large containers or storage vessels commonly called silos. The materials may be in powderorgranularform and include products such as grain, coal, ore and animal feeds.

These silos receive the material from the top and dispense it from the bottom as required, to act as a stored age buffer in the system of delivery from the original source ofthe material to the end user. Such materials are often stored in silos for a significant period without dispensing, and during this period the material will settle and tend to consolidate locally in the silo. As a result, it is not unusual forthe bottom ofthe silo to empty, leaving material somewhere above the bottom ofthe silo supporting itself as a bridge or simplyasan accumulationonthewallsofthesilo.

This invention is related to breaking down accumulations of stored materials including those remaining after a bridge is penetrated and partly dislodged. Evi dently such accumulations can be of great dangerto anyone attempting to enter the silo from the bottom to dislodgethe material from thewall ofthesilo.

There are further hazards because the stored material may be of type subjectto spontaneous combustion because it mixes as dust with the air in the silo. Such a mixture may explode in the presence of a spark caused by metal parts rubbing against one another.

In general,the unpredictable nature of the atmos- phere in silos combined with the possibility ofsud- den collapse of material from the walls ofthesilo, leads to a hazardous situation.

Various methods of breaking accumulations off the walls ofsilos have been tried. In theorythe best approach is to disturb the material from the bottom where there is likely to be maximum compression loading. Once this material is dislodged, stress lines will pass upwardly through the material resulting in fracture and collapse. Clearly it would be very hazardous to attempt to achieve this from underneath the material insidethesilo.

Because of the extreme danger of working from the bottom of a silo, various techniques have been evolved in an attempt two dislodge material from the wall. This has included prodding from the top and otherwise attempting to knock the material offthe wall. There is a tendency for this to compact the material rather than dislodge it because the material is supported from the bottom.

In summary, the problems of breaking accumulated material ofthewalls of silos are quite significant.

It is therefore desirabletofind a method and structure capable of dislodging this material in a predictable fashion without danger to the operator and with no likelihood of causing explosions from spontaneous combustion. For reasons of safety, it is desirable to operate from the top of the silo and yet apply forces two dislodge the material from near the bottom ofthe accumulated material. This invention is directed to a method and apparatus capable of achieving these results.

In a first of its aspects, the invention provides a device for dislodging stored material from the walls of storage vessels such as silos, the device comprising: a main structure having a leading end; means coupled to the main structure for suspending the device inside the storage vessel in horizontal alignment with the material to be dislodged,the leading end being nearerthis material; a pair of arms moveably attached to said leading end for movement in opposition towards and away from one another; actuator means coupled to the main structure and to the arms for causing said movement of the arms; and air supply means having outlets attached to the arms for directing compressed air at the material as the arms move to thereby dislodge the material randomly as the suspending means is used to direct the device towards the remaining material.

In a second of its aspects, the invention provides a device for dislodging stored material from the walls of storage vessels, such as silos, the device comprising: a main structure having a leading end; suspension means attached to the main structure for hanging the device inside the storage vessel and fordirecting the device towards the stored material with the leading end nearerthe material; linkage means coupled to the main structure and having outer ends moveable with a predetermined motion; actuator means coupled to the main structure and to the linkage means and operable to cause said outer ends to move with said predetermined motion; and air supply means anchored to said outer ends for directing compressed air at the stored material as the outer ends move to thereby dislodge the material randomly as the suspension means is used to direct the device towards the remaining material.

In a third of its aspects, the invention provides a method of dislodging stored material from the walls of storage vessels such as silos, the method comprising the steps: suspending a device having an actuator, linkage means coupled to the actuator and air line ends attached to the linkage means inside the vessel; moving the suspension means to bring the device near the material to be dislodged; providing compressed airtothe air linesto cause airto blast from the ends of the air lines; andenergizingtheac- tuatorto causethe linkage means to move the air line ends in a predetermined pattern so that the air blasting from the air lines dislodgesthe material fromthe wall.

These and other aspects of the invention will be better understood with reference to the drawings, in which: Figure lisa side view, partly in section, of an ex emplary silo containing a preferred embodiment of a device according to the invention and shown in position to dislodge an accumulation of material attached to the inside wall of the silo; Figure2 is a perspective view of the device drawn to a largerscalethan that shown in Figure 1 and illustrating the device in a first position and having a portion broken away to show some of the internal parts; Figure 3 is a perspective view of the device suspended in a vertical orientation and with portions removed and other parts broken away to illustrate an actuator mechanism with the device in another position;; Figure 4 is a schematic diagram illustrating the pneumatic circuitry used in the device; and Figure 5is a sectional diagrammatic view of a spool valve used in the device.

Reference is made first to Figure 1 which illustrates a silo designated generally by the numeral 20 and containing a device 22 according to a preferred embodiment of the invention. The device is suspended on a pair of ropes 24,26 and supplied bythree compressed air lines 28,30,32. The silo 20 has a sidewall 34to which an accumulation of stored material 36 is attached and which is to be removed by the device 22.

The exemplary silo includes a bottom frustoconical outlet portion 38 having an opening 40 at its bottom. The silo stands on legs 42 and, at its upper end, has atop 44defining an inlet opening 46 and inspection openings 48. Two of these inspection openings are in use as shown in the drawing to ac commodatethe respective ropes 24,26. Evidently, there can be numerous arrangements using different openings so that the device can be suspended in any position within the silo. Further, by using a combination of ropes as shown, it is possible to bias the device towards the accumulation of materials 36 for reasons which will be explained. For the moment, it is sufficient to understand that compressed air is used to activate the device and also to provide a blast of air dislodge material and break up the accumulation 36.The operation of the device will be better understood with reference to subsequent drawings.

Reference is next made to Figure 2 which illustrates the device 22 looking from the back ortrailing end ofthe device forwardly past the leading end. The device consists of a main structure 50 containing an actuator mechanism designated generally by the numeral 52 and operable to move a pair of arms 54, 56 towards and away from one another. These arms carry nozzles 58,60 at the respective ends of the air lines 30,32 for directing air blasts to dislodge the material 36 (Figure 1). The device is suspended by attachment of the ropes 24,26 (Figure 1) to a pivoted bail 62 at the trailing end ofthe device and a ring 64 towards the leading end of the device.The main structure 50 is in the form of a welded box for strength and carries an end cap 66 having an integral cover 68 for part of the actuator mechanism as well as a connection piece 70 to receive the air line 28 for operating the mechanism 50.

Atthe leading end ofthe main structure 50, a pair of parallel legs 72,74 projectforwardly terminating at an axle76extending between the legs and support ing a pair of similar links 78,80 which are attached to respective tubes 82,84 adjacent their forward ends and with which they are free to rotate on the axle 76.

A spacertube 86 is positioned between the links for location purposes.

The ends of the links 78,80 remote from the axle 76 are pivotally connected to the arms 54,56. These arms are cranked so that outer portions converge in the position shown whereas inner portions diverge and the connection to the links is at the inner port- ions. The arms are pivoted at their inner ends as will be described and at their outer ends, carry respective brackets 88,90 to which the nozzles, 58,60 are attached. Consequently, as the arms move, the flexibility of the tubes 30,32 permits the nozzles to move with the arms to redirect the blasts of airfrom the nozzles in a pre-arranged pattern as will be described.

Reference is next made to Figures 2 and 3, with primary reference to Figure 3 to describe the actuator mechanism 52 and its attachment to the arms 54,56 in more detail.

The mechanism 52 includes a double-acting pneumatic cylinder 92 attached in the main structure 50 such that its piston rod 94 projectsforwardlyter- minating at a crosspiece 96 to which the arms 54,56 are pivotally attached. This crosspiece is also attached to a slave rod 98 extending in parallel with the piston rod 94 into the main structure 50. The slave rod isjournalledin a forward wall 100 ofthestructure 50 and in the cap 66 for movement with the piston rod to bring an adjustable striker 102 into engagement with one of a pair of followers 104, 106 attached to respective pneumatic valves 106, 110.In Figure 3, the striker 102 has engaged the follower 104 and, with reference to subsequent description, will be explained how this striker cooperates with the valves 108, 110 to control the movement of the piston rod 94 and hence the angular operation ofthe arms 54, 56to move the airjets in a predetermined pattern. Forthe moment, it can be seen that Figure 2 shows the striker in engagement with the follower 106 and the arms in a correspondingly closed position,whereas in Figure 3 the striker is in engagement with thefol- lower 104 and the arms are in a separated or open position.

The remainder of the elements of the device will be described with reference to Figures 3 and 4. Compressed air is supplied to the connector piece 70 (as previously mentioned) and this air is available both to a controlling spool valve 112 and to a T-piece 114 mounted on the side ofthe connector piece 70. Following the path through the T-piece, air is available at respective inlets 116 and 118 on the pneumatic valves 108, 110. In the position shown, the valve 108 is open to permitflowto pass from the inlet 11 6to a port 120 on the spool valve 112. As seen in Figure 5, this applies pneumatic pressure in an end cavity 122 of the spool valve, thereby moving spool 124 to the left as drawn.

Returning to Figures 3 and 4, because the valve 110 is closed, there will be noflowto a port 126 on the spool valve so that the pressure on the chamber 122 (Figure 5) can maintain the spool in the position shown in Figure 5. Itwill be seen inthisfigurethatair from the connectorpiece70 is availablethrough an inlet 128 pastthespool 124to a port 130 where itin turn travels (as shown in Figure 4) to a port 132 on the pneumatic cylinder 92. To drive the piston rod 94 upwardly as drawn and thereby moving the arms tow ards the position shown in Figure 2.As this motion takes place, air is displaced through a second port 134 on the pneumatic cylinder 92 and is driven through a further port 136 on the spool valve 112 where, as seen in Figure 5 it is free to pass the spool 124 and leavevia a channel 138 exiting through a sintered metal cover 140 to atmosphere. The motion of the piston will continue until such time as the slave rod 98 carries the striker 102 into engagement with the follower 106 on the valve 110. Atthis point, the valve 110 will be opened and compressed airwill pass through the port 126 ofthe spool valve 11 2to forcethespool 124 to the right (as shown in Figure 5) displacing airfrom the chamber 122.Thespool 124 then takes up a position corresponding to that shown in Figure 5 but reversed in the sense that air can now escape through a second sintered cover 142 to permit the piston to drive the piston rod 94 back to its original position wherethe arms are in thedeflected or open position shown in Figure 3.

The automatic reciprocation of the piston rod will continuejustas long as the air pressure is applied two the pneumatic cylinder. Also the speed of the movement can be controlled by throttling the flow of air to the cylinder.

The nozzles 58,60 (Figure 2) can take many forms including defining multiple outlets. They can be angled to cause a swirling action and they can be combined with flexible ends which will oscillate independently as the air issues from the ends. Such flexible pieces can have chain flails orthe like attached to further enhance the forces and impacts used to dislodge the stored material. The form of the device will be varied to match the requirements for dislodging different materials.

In circumstances where explosion may be a problem the device will be coated in any suitable plastics material to avoid contacts which could cause sparking.

The exemplary device is typical of structures included within the scope of the invention as described

Claims

and claimed. CLAIMS

1. A device for dislodging stored material from the walls of storage vessels such as silos, the device comprising: a main structure having a leading end; means coupled to the main structure for suspen ding the device inside the storage vessel in hori zontal alignmentwiththe material to be dislodged, the leading end being nearerthis material; a pair of arms moveably attached to said leading end for movement in opposition towards and away from one another; actuator means coupled to a main structure and to the arms for causing said movement of the arms for causing said movement of the arms; and air supply means having outlets attached to the arms for directing compressed air atthe material as the arms move to thereby dislodge the material randomly as the suspending means is used to direct the device towards the remaining material.

2. Adevice as claimed in claim 1 in which theactuator means is air-operated, self-reciprocating and double-acting pneumatic device.

3. A device as claimed in claim 1 in which the supports are arms coupled to the actuator means and pivoted on outer ends of respective links having inner ends pivoted on a common axis.

4. A device for dislodging stored material from the walls of storage vessels, such as silos, the device comprising: a main structure having a leading end; suspension means attached to the main structure for hanging the device inside the storage vessel and for directing the device towards the stored material with the leading end nearerthe material; linkage means coupled to the main structure and having outer ends moveable with a predetermined motion; actuator means coupled to the main structure and tothe linkage means and operableto cause said outer ends to move with said predetermined motion; and air supply means anchored to said outer ends for directing compressed air at the stored material as the outer ends move with said predetermined motion to thereby dislodge the material randomly as the suspension means is used to direct the device towards the remaining material.

5. A device as claimed in claim 4 in which theac- tuator means is a double-acting pneumatic cylinder and includes means causing the cylinder to reciprocate automatically.

6. A device as claimed in claim 4 in which the air supply means includes airjectsto better directthe air.

7. A device as claimed in claim 4 in which the actuator means includes a double-acting pneumatic cylinder.

8. A method of dislodging stored material from dislodging stored material from the walls of storage vessels such as silos, the method comprising the steps: suspending a device having an actuator, linkage means coupledtothe actuatorand airline ends attached to the linkage means inside the vessel; moving the suspension means to bring the device near the material to be dislodged; providing compressed airtothe air lines to cause airto blast from the end ofthe air lines; and energizing the actuator to cause the linkage means to move the air line ends in a predetermined pattern so that the air blasting from the air lines dislodges the material from the wall.

9. A method as claimed in claim 8 in which the actuator is energized by compressed air.

10. A device substantially as herein described in accordance to and as shown in the accompanying drawings.

11. A method of dislodging stored material from the walls of storage vessels substantially as herein described with reference to the accompanying drawings.

12. Any novel feature or combination offeatures disclosed herein.