GB2128571A - Apparatus for transferring particulate material from one position to another - Google Patents

Abstract

Apparatus for transferring particulate material from one position to another which minimises manual stress and avoids the creation of dust. It comprises a transfer duct (1, 3) with a conical cover (2) at one end providing an inner conical surface (S) which is presented to the surface of the bulk particulate material (5) to be transferred from the first position. The conical cover has a channel (10) around its rim to which air can be admitted and directed along the surface (S) so providing a fluidic interface between the surface (S) and the bulk material whereby when a pressure drop is introduced along the transfer duct (1, 3), the material flows therealong to the other position. <IMAGE>

Description

SPECIFICATION Apparatus for transferring particulate material from one position to another FIELD OF THE INVENTION The present invention relates to apparatus for transferring particulate material from one position to another, in particular for use in transferring powders and granules from a bulk source into small packets.

BACKGROUND ART In the field of packaging and dispensing powders and granules into small packets the filling machinery from which the powders and granules is dispensed is provided with hoppers which have to be loaded with powder from a bulk source.

In the food and pharmaceutical industries the bulk source may be either kegs or sacks, and in some cases transfer from such a bulk source to the filling machine is carried out manually using a scoop. In more recent times this primitive method has been replaced by making use of screw elevators and other such mechanical lift devices in order to raise and discharge the powder into the filling machines.

In the majority of the prior art lift devices it is a requirement that the sack or keg be tipped into the hopper at ground floor level by an operative from which the lifting device then elevates the product automatically. The act of tipping is not only strenuous manually, but inevitably creates dust which under modern health and safety environmental standards is not desirable.

To obviate the disadvantages involved in tipping, use can be made of suction devices such as large vacuum cleaners in which the operator inserts a probe into the keg or sack and the powder is raised using large quantities of air to carry it upwards. This expedient is not only labour intensive but also results in the entrainment of a considerable amount of air in the powder products which can be disadvantageous from the point of subsequent packaging.

SUMMARY OF THE INVENTION It is an object of the present invention to enable particulate material to be transferred from one position to another without significant air entrainment in the powder and without the creation of dust, particularly where the particulate material is to be transferred from kegs or sacks for filling small packages.

According to the invention there is provided apparatus for transferring particulate material from one position to another comprising a transfer duct for movement of the material from a first position to discharge at a second position, means attached to one end of the duct providing a surface to be held against or adjacent the material at said first position as the level of the material drops during transfer to said second position, and through which communication is maintained for passage of the material to said transfer duct, and means for introducing air or similar gaseous medium along said surface to provide a fluidic interface between that surface and said material whereby when a pressure drop is provided along the transfer duct between said one end thereof and said discharge, the material is caused to flow through the transfer duct to discharge at said second position.

The advantage of this arrangement is that since basically it provides a closed system, the creation of dust by, for example, a need to transfer the material to the second position by lifting and tipping, is avoided. Moreover since any introduced air is provided merely to form the fluidic interface, very little air is trapped in the material being transferred from the first position to be subsequently dispensed from the discharge point.

It is advantageous that the pressure differential is created by providing a vacuum at a point downstream of the transfer duct and applying a force acting to urge the material into the transfer duct upstream of the applied vacuum. The action of forcing the material into the transfer duct in this way may be carried out by employing the use of a pneumatic lift to raise a storage container for the material at said first position towards the surface of the attachment means which is held stationary.

On the discharge side of the transfer duct the vacuum may be held by a flap valve so that the vacuum may be pulsed in order to alternately load the discharge and release it into a filling machine residing at the second transfer position.

Advantageously the surface of the attachment means may be inwardly conical with the inlet to the duct positioned at its apex. This arrangement additionally assists in guiding the particulate material to the duct under the influence of the fluidic interface.

Other features and advantages of the present invention will become apparent from the following description having reference to a preferred method of carrying out the invention.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention therefore will now be described by way of example with reference to the sole accompanying drawing which shows schematically, apparatus for transferring particulate material from a stored position to a discharge position.

BEST MODES OF CARRYING OUT THE INVENTION The apparatus for transferring particulate material from one position to the other, particularly from a keg or sack to a filling machine for subsequently dispensing into small packages, comprises a vertically extending transfer duct 1, the inlet end of which is provided with a conical cover 2 and the outlet end leading into an inclined discharge tube 3.

The conical cover 2 is shown inserted within a container 4, for example a keg or sack, containing bulk particulate material 5 with access to the inlet end of the duct 1 being through an aperture or opening in the apex of the conical cover 2.

The container 4 is supported on a pneumatic lift as indicated at 6 but not shown in detail, and the arrangement of the various parts is such as shown in the drawing, that the conical cover 2 is in contact with the bulk material 5 in the container 4.

The discharge end of the discharge tube 3 is provided with a flap valve 7, while the other end of the discharge tube 3 has an outlet 8 for connection to a vacuum source (not shown).

The conical cover 2 is provided with an air inlet 9 which opens into a channel 10 arranged around the inner periphery of the conical cover 2. The channel 10 opens out along its top inner edge 11 so that air introduced through the inlet 9 is directed into the container 4 and along the interior surface S of the conical cover 2.

In operation the powder 5 from the container 4 is drawn up the transfer duct 1 by the pressure differential created by the vacuum at the upper end of the discharge tube 3 and the pressing action of the powder being forced into the transfer duct 1 under the action of the pneumatic lift 6.

The conical cover 2, due to the inclined nature of its internal surface, directs and presents the powder to the inlet end of the discharge tube 1 and is aided in this function by the introduction of very small quantities of air from the outlet of the channel 10 and along the inner surface of the cover 2, the air effectively fluidising the material in intimate contact with the cover 2 thus encouraging and assisting movement of the material into the transfer duct 1.

The vacuum at the upper end of the discharge tube 3 is held during the lift operation by the flap valve 7. Release of the material collected at the lower end of the inclined discharge tube 3 to a filling machine (not shown) may be carried out intermittently by pulsing the vacuum as required.

The system as described is effectively closed thus avoiding the production of dust during a filling process. Moreover since only a small quantity of air is admitted through the inlet 9 there is no excessive entrapment of air in the particulate mass being passed through the transfer duct 1 and eventually to be discharged into the individual small packages.

The maximum height to which powder may be theoretically lifted by the device as described much depends upon the powder density but in practical terms it is envisaged that the device is capable of lifting most powders up to a height of 15 feet using a single lift module. It is most likely that greater lifts will be achieved using multiple modules.

The present invention has been described in a preferred way with reference to the emptying of kegs and sacks but of course it is readily usable for emptying much larger containers for example silos or large bins where the conical cover 2 would be in inverted relationship with respect to the contents of the container. In such a situation the apparatus would not require a pneumatic lift since the material to be discharged could be kept in contact with the conical cover under gravity assistance.

Moreover it is conceivable that instead of employing a pneumatic lift, as in the above described embodiment, to raise the storage source i.e. kegs or sacks, the transfer duct 1 and connected parts could be removed relative to the storage source which is maintained stationary.

Finally the apparatus of the invention has been discussed with reference to the packaging of powder in small containers but any application which requires the transfer of particulate material from one position to another would be eminently solved by the apparatus according to the invention.

Claims (6)

1. Apparatus for transferring particulate material from one position to another comprising a transfer duct for movement of the material from a first position to discharge at a second position, means attached to one end of the duct providing a surface to be held against or adjacent the material at said first position as the level of the material drops during transfer to said second position, and through which communication is maintained for passage of the material to said transfer duct, and means for introducing air or similar gaseous medium along said surface to provide a fluidic interface between that surface and said material whereby when a pressure drop is provided along the transfer duct between said one end thereof and said discharge, the material is caused to flow through the transfer duct to discharge at said second position.

2. Apparatus as claimed in claim 1 wherein said attachment means is a conical cover providing an inner conical surface which is presented to the material to be transferred.

3. Apparatus as claimed in claim 2 wherein said means for introducing air is a channel around the rim of said conical cover, the channel having a peripheral opening allowing admitted air to be directed along said inner conical surface.

4. Apparatus as claimed in any preceding claim and including a container holding a particulate material to be transferred, said surface of said attachment means being presented to the body of material in said container, and means for maintaining the body of material against the said surface as the level of material falls during transfer from said first position to said second position.

5. Apparatus as claimed in claim 1 wherein a discharge duct is provided for material transferring to said second position, a vacuum at one end of the discharge duct for producing said pressure drop whereby to collect particulate material in said discharge duct, and a flap valve at the other end of said discharge duct operable to allow the collected material to pass to said second position.

6. Apparatus for transferring particulate material from one position to another substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.