GB1605129A

GB1605129A - Granular material handling

Info

Publication number: GB1605129A
Application number: GB4821/77A
Authority: GB
Original assignee: FOUNDRY EQUIPMENT International
Current assignee: FOUNDRY EQUIPMENT International
Priority date: 1977-02-05
Filing date: 1977-02-05
Publication date: 1981-12-16
Also published as: NL7801235A; FR2379318A1; FR2379318B3; ES466668A1; IT7847928A0; BE863680A; IT1101756B; DE2804679A1

Description

(54) GRANULAR MATERIAL HANDLING (71) We, FOUNDRY EQUIPMENT INTERNATIONAL LIMITED, a British Company, of Linslade Works, Leighton Buzzard, Bedfordshire, LU7 7LL, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to granular material handling and particularly to the reduction of agglomerated granular material to separate grains. The invention is especially applicable to recycling of casting sand.

Relatively lightly bonded lumps of sand residues from foundary casting processes employing chemically bonded sands are reduced to grain sand for recycling by subjecting an aggregate of such lump sand residues to attrition by means of vibration in a suitable apparatus.

It is an object of one aspect of the present invention to provide an improvement in ap paratus for the reduction of agglomerated grain material to separate grains.

Accordingly the invention seeks to achieve this object by subjecting the aggregate mass of the apparatus to circular excitation. Pre-.

ferably, the entire mass is subjected to the.

substantially same polar or circular pattern of vibration.

A suitable polar pattern of vibration may be produced in a reclaimer apparatus having an exciting out-of-balance motor, or similar such orbital body at, or close to, the effective centre of mass of the apparatus, the body of which is carried on flexible mountings.

Low or negligible directional restraints, are imposed fluid mounts by such for example as inflated pneumatic (air) or hydraulic (water) mounts.

Previous attrition apparatus have tended to cancel one or more components of true circular motion or to introduce substantial linear components, often due to the use and interaction of cooperating pairs of vibrator motors or a lack of symmetry of the motor position relative to the apparatus and its mass and weight even when loaded.

In a preferred form of apparatus, a chamber containing the aggregate mass is so shaped in the plane of vibration that grain sand as it is generated is concentrated towards the centre of mass of the apparatus. Such concentrated grain sand can conveniently be removed from the aggregate mass through fine slots in the chamber base plate positioned so that the sand grains pass over acceptance screens located in the lower body of the apparatus on each side of the vibratory motor. Acceptable sand passes through the screens and is discharged down inclined chute plates at one end and oversize reject material diverted for collection at the other end of each leg.

Frequently the processed grain sand is removed and elevated for de-dusting and storage and for this purpose a pneumatic suction conveyor is used. A problem arises in uansferring the sand to the stationary suction conveyor from the vibrating reclaimer body.

An object of a further aspect of the invention is to improve the transference of granular material from a vibrating body to a suction conveyor. Accordingly it is arranged for the reclaimed sand to be collected into a receiver pot attached to the vibrating body of the reclaimer. The stationary end of an input pipe of the suction convey line is positioned in the pot and picks up sand as the vibrating level rises in the reception pot. Provision for induction of the necessary conveying air is made according to one embodiment by chamfering the end of the suction line input pipe. In an alternative embodiment the end of the suction line input pipe with square end is inserted into a clearance tube.

Embodiments of the invention will now be described by way of example and with reference to the accompanying schematic drawings in which: Figure 1 shows a section through a vibratory reclaimer at right angles to the rotational axis of the vibratory mass.

Figure 2 shows a partial sectional view of a coupling between a vibratory apparatus and a stationary conveyor having a chamfered input pipe end and Figure 3 shows a similar view to that of Figure 2 with the input not chamfered but inserted into a co-axial tube secured to a container attached to the apparatus.

A vibratory apparatus body 10 comprises an upper open topped chamber 11 to receive lumps of agglomerated sand. The bottom plate 12 of the chamber has sides 13 sloping downwards to a central portion 14. Vibratory means in the form of an out-of-balance motor 15 is secured to the underside of the central portion 14.

The upper chamber 11 is supported by leg chambers 16 disposed each side of the motor 15 and the central portion 14, each leg chamber being flexibly secured to the floor or ground by a supporting flexible mounting 17.

Slots 18 at the junction of the central portion with each sloping side 13, allow sand to pass from the upper chamber 11 into each leg chamber 16.

In each leg chamber a fine mesh screen 19 is arranged beneath the slots 18 and slopes downwards away from the centre of the apparatus. An inclined chute 20 extends along the lowermost edge of each screen 18 to collect particles which do not pass through the screen and divert them to an outlet at one end of the apparatus, an inclined chute 21 extends beneath each screen to collect the reclaimed sand and deliver it to an outlet at the opposite end of the apparatus.

Mass balance weights 22, in the base of each leg chamber serve to adjust the centre of gravity of the apparatus to be close to the axis of the motor 15.

In operation, the out-of-balance motor induces a circular motion to the apparatus body and hence to the lumps of sand in the upper chamber wherein attrition takes place as the lumps vibrate.

The sloping lower surface of the chamber ensures that the grain thereby produced tends to accumulate near the centre of gravity of the apparatus, namely the central area 14, before passing through the slots 18.

Figure 2 shows the arrangement for transference of the sand from the vibrating machine to a stationary suction conveyor pick-up in which sand from the leg chamber outlets passes over sloping chute connections 25 into an open-topped container or pot 26, firmly attached to the vibrating body as indicated diagrammatically at 27. The independently and usually rigidly supported end of the suction conveyor line input pipe 28 extends into the container 26 to remove grain sand as the vibrating free surface rises, provision for induction of the necessary conveying air being made by chamfering the end of the pipe, as shown at 29. The chamfered portion 29 of the pipe extends from adjacent the bottom of the container to a position above the end of the chute connection 25.

In the alternative arrangement of Figure 3, the pipe 28 has a non-chamfered end and is inserted into a clearance tube 30 which extends downwards from the top 31 of the container 22, to a position near to the bottom of the container. The necessary con veying air is inducted by way of the space between the clearance pipe and the tube as shown by the arrows. The clearance tube 30 could, of course, be fixed to the pipe 28 and extend with clearance into the con tainer 22 as by an open top thereof.

WHAT WE CLAIM IS: 1. Attrition apparatus for reducing ag glomerated granular material, comprising a chamber for receiving lumps of the ag glomerated material and underlying screening and material removal chambers flanking means for vibrating the apparatus with its substan tially circularly directed action.

2. Attrition apparatus according to claim 1, wherein each removal chamber is within a supporting leg of the apparatus.

3. Attrition apparatus according to claim 2, wherein each supporting leg carries at least one floor mount of a flexible fluid filled type.

4. Attrition apparatus according to claim 1, 2 or 3, wherein the means for vibrating comprises an out-of-balance motor with a rotation axis through or close to the effec tive centre of mass of the apparatus in operation.

5. Attrition apparatus according to any preceding claim, wherein a single out-of balance motor is mounted to and below a central bottom of the material receiving chamber.

6. Attrition apparatus according to claim 5, wherein the material receiving chamber slopes downwardly to its said central bottom and is apertured for release of reduced material adjacent to said bottom.

7. Attrition apparatus according to claim 6, wherein each removal chamber includes separated inclined material removal chutes one covered by a screen to pass sufficiently fine material and the other to receive material rejected by the screen.

8. Attrition apparatus according to any preceding claim, wherein lower parts of the removal chambers afford accommodation for weights to set the effective centre of mass of the apparatus.

9. Attrition apparatus according to any preceding claim, further comprising delivery means for fine material from said removal chambers in the form of at least one container mounted to vibrate with the apparatus delivery passage means thereto for fine material, and clearance accommodation for suction take-off means.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

Figure 3 shows a similar view to that of Figure 2 with the input not chamfered but inserted into a co-axial tube secured to a container attached to the apparatus.

A vibratory apparatus body 10 comprises an upper open topped chamber 11 to receive lumps of agglomerated sand. The bottom plate 12 of the chamber has sides 13 sloping downwards to a central portion 14. Vibratory means in the form of an out-of-balance motor 15 is secured to the underside of the central portion 14.

The upper chamber 11 is supported by leg chambers 16 disposed each side of the motor

15 and the central portion 14, each leg chamber being flexibly secured to the floor or ground by a supporting flexible mounting 17.

Slots 18 at the junction of the central portion with each sloping side 13, allow sand to pass from the upper chamber 11 into each leg chamber 16.

In each leg chamber a fine mesh screen

19 is arranged beneath the slots 18 and slopes downwards away from the centre of the apparatus. An inclined chute 20 extends along the lowermost edge of each screen

18 to collect particles which do not pass through the screen and divert them to an outlet at one end of the apparatus, an inclined chute 21 extends beneath each screen to collect the reclaimed sand and deliver it to an outlet at the opposite end of the apparatus.

Mass balance weights 22, in the base of each leg chamber serve to adjust the centre of gravity of the apparatus to be close to the axis of the motor 15.

In operation, the out-of-balance motor induces a circular motion to the apparatus body and hence to the lumps of sand in the upper chamber wherein attrition takes place as the lumps vibrate.

The sloping lower surface of the chamber ensures that the grain thereby produced tends to accumulate near the centre of gravity of the apparatus, namely the central area 14, before passing through the slots 18.

Figure 2 shows the arrangement for transference of the sand from the vibrating machine to a stationary suction conveyor pick-up in which sand from the leg chamber outlets passes over sloping chute connections 25 into an open-topped container or pot 26, firmly attached to the vibrating body as indicated diagrammatically at 27. The independently and usually rigidly supported end of the suction conveyor line input pipe 28 extends into the container 26 to remove grain sand as the vibrating free surface rises, provision for induction of the necessary conveying air being made by chamfering the end of the pipe, as shown at 29. The chamfered portion 29 of the pipe extends from adjacent the bottom of the container to a position above the end of the chute connection 25.

In the alternative arrangement of Figure 3, the pipe 28 has a non-chamfered end and is inserted into a clearance tube 30 which extends downwards from the top 31 of the container 22, to a position near to the bottom of the container. The necessary con veying air is inducted by way of the space between the clearance pipe and the tube as shown by the arrows. The clearance tube

30 could, of course, be fixed to the pipe

28 and extend with clearance into the con tainer 22 as by an open top thereof.

WHAT WE CLAIM IS: 1. Attrition apparatus for reducing ag glomerated granular material, comprising a chamber for receiving lumps of the ag glomerated material and underlying screening and material removal chambers flanking means for vibrating the apparatus with its substan tially circularly directed action.
2. Attrition apparatus according to claim 1, wherein each removal chamber is within a supporting leg of the apparatus.
3. Attrition apparatus according to claim 2, wherein each supporting leg carries at least one floor mount of a flexible fluid filled type.
4. Attrition apparatus according to claim 1, 2 or 3, wherein the means for vibrating comprises an out-of-balance motor with a rotation axis through or close to the effec tive centre of mass of the apparatus in operation.
5. Attrition apparatus according to any preceding claim, wherein a single out-of balance motor is mounted to and below a central bottom of the material receiving chamber.
6. Attrition apparatus according to claim 5, wherein the material receiving chamber slopes downwardly to its said central bottom and is apertured for release of reduced material adjacent to said bottom.
7. Attrition apparatus according to claim 6, wherein each removal chamber includes separated inclined material removal chutes one covered by a screen to pass sufficiently fine material and the other to receive material rejected by the screen.
8. Attrition apparatus according to any preceding claim, wherein lower parts of the removal chambers afford accommodation for weights to set the effective centre of mass of the apparatus.
9. Attrition apparatus according to any preceding claim, further comprising delivery means for fine material from said removal chambers in the form of at least one container mounted to vibrate with the apparatus delivery passage means thereto for fine material, and clearance accommodation for suction take-off means.
10. Attrition apparatus according to claim

9, comprising a suction take-off pipe with a chamfered end extending into said container.
11. Attrition apparatus according to claim 9, comprising a suction take-off pipe within a clearance pipe both extending into said container and the clearance pipe terminating above the maximum level for the fine material to be taken-off.
12. Attrition apparatus arranged and adapted to operate substantially as herein described with reference to and as shown in the accompanying drawing.