WO1991017104A1

WO1991017104A1 - Portable storage and dispensing apparatus

Info

Publication number: WO1991017104A1
Application number: PCT/GB1991/000418
Authority: WO
Inventors: Michael John Nugent; Paul Robert Beaver
Original assignee: Michael John Nugent
Priority date: 1990-05-03
Filing date: 1991-03-18
Publication date: 1991-11-14
Also published as: AU7461291A

Abstract

Portable storage container from which dry cement powder or other particulate material is dispensed via apertures (22) in a tube housing a horizontal screw conveyor. Roof shaped members (21) are transversely affixed between apertures (22), forming hopper-like configurations to disrupt compaction of stored material and provide zones (43) whereby material is directed to the screw conveyor. Agitator (27) operates within zones (43). Material is dispensed via outlet (4) by manual rotation of the screw conveyor using a handle. Closure to outlet (4) is spring loaded to seal the container between each dispensing operation. The conveyor cannot be rotated unless lever (30) is first operated. The apparatus is primarily intended for use in conjunction with a bulk storage silo.

Description

PORTABLE STORAGE AND DISPENSING APPARATUS

The invention comprises a portable container for the storage, handling and dispensing of dry powders and particulate materials. It offers improvements to the use of such containers, in particular to the dispensing of the stored material by means of a horizontal screw conveyor. The invention is primarily but not exclusively intended to replace the use of paper sacks for cement powder.

The invention relates to the use of 50kg paper sacks for cement powder. Problems exist with their use from the point of manufacture to the point of use as they require to be transported, handled and stored several times. Other disadvantages are as follows: Firstly, the sacks are difficult to handle. Secondly, the life of the sacks on site is relatively short due to the action of moisture in the atmosphere. Thirdly, the sacks tend to become torn, whereby cement powder is wasted. Fourthly, it is necessary to provide covered storage for the cement sacks. Fifthly, there are security problems since such sacks are readily stolen. Sixthly, half-used or empty sacks are a source of litter on building sites. Thus the usage costs of cement in sacks is high when wastage, theft, transport, storage, handling and litter are taken into consideration.

In the case of dry cement powder it is known for storage containers to employ a horizontal screw conveyor to discharge cement powder from a transportable storage container. It has been found that cement will compact all around a screw conveyor mounted in a trough at the bottom of the container so that the conveyor is difficult to rotate. This can be due to the superimposed weight of the powder or an excess of powder causing the conveyor to clog or choke.

It has been tried or contemplated as a solution to this problem to cover the screw conveyor with moveable and mechanically operable slides or cover plates or the like. These mechanisms must be repeatedly operated unless all of the powder in the container is removed at one time.

It has also been found that cement powder can bridge within a container above a conveyor leaving a void between the powder and the conveyor. Agitator mechanisms are needed to collapse the bridged powder. These mechanisms are in addition to the operable cover plates, slides or the like already referred to. This is an inconvenient method of preventing compaction of cement causing difficulty in removing it from the container. Further, such anti- compaction mechanisms known to exist in containers for cement powder are relatively complex and difficult to service or repair.

It is conditional to the use of such containers that a closable valve is provided at an outlet from which the stored material is dispensed. It is required that this valve is opened prior to dispensing of material and then closed between each dispensing operation to prevent moisture ingress to the container. A consequent problem is that while the container is in use, the closure valve is left in the open position thus allowing of moisture ingress to the container.

Also the conveyor may be rotated while an outlet closure valve is in the closed position. This results in compaction of material within the outlet of the container which can lead to seizure of the screw conveyor so that it cannot be rotated.

It is therefore the object of the present invention to provide a method and apparatus which is easy to manufacture, use and service; for the storage and subsequent dispensing of cement power and other particulates. The invention also offers improvements -to one or more of the matters discussed above or generally. The present invention does not require the use of moveable and mechanically operated cover plates or the like above a horizontal screw conveyor. It provides a practical and non- operable solution to the problem of superimposed weight of material above a screw conveyor. In addition, it provides a method and apparatus offering a solution to the problems already defined herein as found relevant to the storage and subsequent dispensing of dry cement powder from a container using a horizontal screw conveyor.

According to the invention, there is provided an apparatus for storing and dispensing particuiate materials, particularly cement powder as defined in the accompanying claims.

In an embodiment described below, an apparatus for storing and dispensing cement powder or other particuiate materials comprises providing storage apparatus including a closable storage container. The container is adapted to be portable. For example, it can be mounted on a trailer or it can be handled by a fork lift truck. The container provides a sealed and substantially airtight storage vessel for cement powder having a lid that may self-close e.g. by counterweight. It can be filled from a bulk storage silo and then the contents dispensed from the container by means of a screw conveyor sitting in a tube. The side walls of the container slope downwards and inwards to join with the tube which is horizontal and runs lengthwise of the bottom of the container.

The tube has roof-like members that are spaced at intervals along its length, the apexes of which span the container and the lower edges of which are shaped and fitted to the tube and the ends to the side walls of the container. The roof- shaped members act to make discontinuous the compaction of the stored cement powder in the lower portion of the container. They also form in combination with the side walls of the container a series of hopper-like configurations which distribute the weight of the stored powder and provide a series of zones within which the powder is readily agitated and directed to apertures in the tube.

An agitator shaft extends end to end within the container and is supported centrally above the tube by brackets affixed to the apexes of the roof-like members. From the agitator shaft, rods extend downwards into the zones of the container provided by the hopper-like configurations. The shaft and rods are manually activated by movement of a lever or wheel outwith the container.

The agitator shaft is covered by a roof-like member to facilitate the operation of the agitator and to distribute the weight of the stored powder above the apertures.

The size of the apertures in the tube controls at all times the amount of material having contact with the screw conveyor, so that when rotated, the conveyor itself agitates the cement powder and moves it within the tube towards the outlet but does not become choked with excess of powder and difficult to rotate.

At the outlet end of the tube the powder falls by gravity through a downtube, housing a closure means in the form of a butterfly valve, to seal the container against the ingress of moisture.

Adjacent to the outlet, a lever-operated encatchment is provided to prevent the conveyor shaft from being turned. When operated the lever does allow the conveyor to be rotated and also causes the outlet closure valve to become open. On being released, the encatchment lever automatically returns to position, closing the outlet valve and preventing further rotation of the screw conveyor. This provision makes it impossible for the operator or another person to leave the outlet closure valve open or to cause compaction of the stored material in the outlet or tube by rotating the conveyor when the valve is shut.

An embodiment of the invention will now be described by reference to the accompanying drawings. According to which: Figure 1 shows a side elevation of the apparatus according to the embodiment of the invention described.

Figure 2 shows the apparatus viewed from the dispensing end of the invention.

Figures 3 and 4 show the construction of the apparatus viewed from above.

Figures 5 and 6 show details of the dispensing end of the apparatus.

As shown in the drawings, the storage and dispensing container (1) is adapted for use with a fork lift truck, having welded support struts (2) to container (1) and support members (3) to raise the container to a height above the ground sufficient to place a bucket below outlet (4) . The apparatus further comprising a container or tank (1) with flat end walls (5), vertical (6) and sloping (7) side walls tapering down and welded to tube (8), in which is located a screw conveyor, having a helical flight (10) mounted on an axial shaft (11) constituting a discharge member.

The apparatus is generally of mild steel, with support struts (2) being open ended at (12) to receve lifting forks for transportation.

Filler opening (13) comprises a flanged collar (14) welded to an opening in container (1) and having a hinged and flanged lid (16) which can self close by a counterweight or spring(s) (not shown) and be held closed by an over-centre cam (also not shown). A rubber or equivalent seal (20) is provided on inner face of lid (16) for sealing purposes.

Tube (8) has roof-like members (21) between apertures (22) spaced at intervals along its length, the apexes of which span the container (1) and the lower edges of which are shaped and fitted to the tube (8). The ends of members (21) are fixed to the side walls (7) of the container. The sloping sides of the roof-shaped members (21) combine with the sloping side walls (7 ) of the container (1) forming a series of hopper-like configurations that make discontinuous the compaction of stored material and direct it to apertures (22) in the tube (8) .

The screw conveyor is supported on end bearings (23) and (24) so as to provide minimal clearance (1 to 3 millimetres) between flight (10) and inner face of the tube (8). Shaft (11) projects through both end walls of container (1) and is there secured by removable bearing plates. At the outlet end of the container the conveyor shaft (11) is fitted with driving pin (38).

Agitator assembly comprises a shaft (25) supported on bearings at each end of the container and at intervals by brackets (26) mounted upon the apex tops of the roof-shaped members (21). The agitator shaft is placed centrally above apertures (22) and has extending downwards from it, rods (27) which, when the agitator shaft is operated by movement of a lever (28), agitate the stored material within the zones (43) provided by the said hopper-like configurations. Agitator shaft (25) is covered by roof shaped member (29) to facilitate operation of agitator assembly and distribute weight of stored powder above apertures (22).

At the outlet (4) lever (30) operates butterfly flap (32) and, via links (33) and crank arms (34) on shaft (35), it operates stop cams (36) on either side of conveyor shaft (11) which prevent engagement of dog clutch (37) with driving pin (38) on shaft of conveyor (11).

Moving lever (30) through 90° opens butterfly flap (32) and rotates stop cams (36) through 90° thus allowing the dog clutch (37) to move longitudinally within sleeve (47) to engage driving pin (38) on shaft (11) of conveyor. Final flight (39) of the screw conveyor has opposite reverse action twist to direct material to outlet. Eearing plate ι43- hol s housing cover plates (46) for bearing (24) to conveyor shaft : 11) and at (45) for felt washer (not shown) which protects searing (24) from dust. Leg of spring i41 ) is neid by groove in welded lug (44) to operate shafts (42).

Dog clutch (37) has squared end (40) to receive handle (not shown) for manual rotation of conveyor. Lever (30) is spring loaded (41) at shafts (42) and (35) to close flap (32) and disengage dog clutch (37) when lever (30) is released by causing reverse action of links (33) and crank arms (34) on shaft (35), and cams (36) on shafts (42). When lever (30) is rotated through 90° to open flap (32), cams (36) rotate to abut with bearing plate (43) to act as stop to lever (30) when flap (32) is in fully open position.

In use the container is filled through filler opening (13)^' from, for example, a static bulk cement silo. The lid is then shut and screwed down into airtight sealing engagement with flanged collar (14). Dry cement powder is subsequently dispensed from the container by operating lever (30) and rotating the conveyor by means of a handle (not shown), to dispense the stored powder into a bucket or similar through outlet (4). On cessation of dispensing and release of lever (30) the closure flap (32) will automatically operate to reseal outlet (4).

In this embodiment the container is transported to the filling silo. It is then returned to site and can be readily moved around the building site. In this way cement powder is obtainable quickly and easily when and where required.

Among the advantages offered by the invention are the following:

1. Substantial savings over cement wastage in comparison with paper sacks. Such losses, it is felt, could be reduced from 25% to 5% or less. 2. Elimination of the labour requirement involved in the storage and handling of cement in paper sacks.

3. Greatly increased storage life of cement powder in comparison to that offered by paper sacks. 4. Improved security of cement powder due to working parts of the invention, such as lever (30), being easily made lockable against theft.

5. The invention may be used to store and dispense any other particuiate powder or granulate material which requires protection against moisture or insect or rodent pest.

6. The dispensing of contents does not require the use of motor power. It is therefore energy saving and quiet in use. 7. The invention may be of merit in relation to materials used in the manufacture of foodstuffs, for example flour, and indeed for ingredients in the manufacturing of industrial goods.

It is considered that the following modifications may be within the scope of the claims:

1. Change to the shape of the container.

2. Angle of pitch of members (21) suited to density, weight, and angle of repose of the material to be stored. 3. Members (21) and (29) together with agitator assembly (25) and (27) may be removably affixed within the container to facilitate cleaning or repair, access for which purpose being via filler opening (13).

4. Apertures (22) may be differently sized within a container appropriate to the dispensing of the material to be stored.

5. Affixed members (21) may have an additional angle of pitch so as to modify zones (43).

5. An arcuate trough may be used where appropriate to house the screw conveyor (9), then members (21) may each be provided with an additional curved bottom side to sit compatibly over the conveyor. 7. The outlet (4) may be positioned integral to the dispensing end of the container with consequent change to position of lever (30) and arrangement of mechanism for clutch (37) . S. The invention may be made of, or lined with, a variety of materials.

9. The container may be made larger with additional members (29) being placed and affixed in the upper portion of the container. These may be transversly placed. Additional means of agitation (25-28) may also be employed in the upper portion of the container with shaft(s) (25) being also transverse to length of the container.

10. Agitator shaft (25) may be operated by means of a wheel instead of lever (28). Shaft (25) may have additional members (27) of differing lengths, which may be affixed at varying angles to shaft (25).

Claims

CLAIMS :

I. Portable storage and dispensing container (1) for particuiate material having a lid (16) through which container is filled with material and an outlet opening through which stored material is subsequently dispensed (4), characterised in that both said lid (16) and outlet (4) are closable against ingress of moisture to the container and that a horizontal screw conveyor is provided lengthwise to the bottom of the container, whereby stored material can be discharged through said 0 opening (4) and further characterised by having provision to prevent the compaction or bridging of the stored contents causing difficulty in getting the contents from the container (1) in controlled small quantities through the outlet opening (4).

5 2. A storage and dispensing container according to claim 1 characterised in that side walls of the container (1) slope downwards and inwards to join with a tube (8) housing a screw conveyor horizontally lengthwise of the bottom of the container, said tube (8) having apertures 0 (22) spaced at intervals along its length to control quantity of material having access to the conveyor, and further characterised in that roof-shaped members (21) are transversely affixed to said tube (8) and/or inner sloping side walls (7) of the container (1) so as to form 5 hopper-like configurations leading to said apertures (22) in said tube (8) .

3. A storage and dispensing container according -co claims 1 or 2 characterised by having provision to agitate stored material within the zones (43) of the container (1) iϋ provided by the said hopper-like configurations, said means of agitation being a shaft (25) supported by or above said roof-shaped members (21), said shaft (25) bearing affixed rods (27) at an angle or angles to it extending into said zones (43), said shaft *(25) beinσ operated by a lever (28) or wheel outwith the container and further characterised by having fixed above said agitator shaft (25) a roof-like member (29) lengthwise end to end of said container.

4. A storage and dispensing container according to claims

1, 2, or 3 having provision to prevent the ingress of moisture to the container via said outlet for dispensing (4) characterised in that closure means (32) to said outlet will automatically close after each dispensing operation.

5. A storage and dispensing container according to claims 1,

2, 3, or 4 characterised by having provision to make impossible the operation of said screw conveyor to dispense the stored material unless lever (30), to operate mechanism (33), (34), (36), (37), to open outlet closure seal (32) is first operated and further characterised in that said mechanism w ll act automatically to close and reseal the outlet (4) while preventing operation of the screw conveyor between each dispensing operation.

6. A portable storage and dispensing container according to claims 1-5 characterised in that all parts necessary to the operation of the apparatus may be made removable from the said container thereby providing a method whereby the apparatus is easily cleaned, repaired, or serviced.

7. A method of storing and dispensing according to claims 4 or 5 whereby the integrity of the stored material is protected against human failure to operate lever (30) tc close valve (32) to dispensing outlet (4) of container (1).

8. A method of extending the utility of buik storage silos by providing means to take smaller quantities of stored material from such silos.

9. A method whereby material may be transferred from a bulk storage silo without difficulty of handling the said material and then be transported and kept in like condition to a bulk silo.

10. A method of dispensing stored powder or particuiate material successively in small amounts from a container by means of a horizontal screw conveyor using any combination of the features defined in claims 1-5.