CRUSHING DEVICE PROVIDED WITH AN EXHAUST SYSTEM AND METHOD FOR CRUSHING HETEROGENEOUS CHUNKS OF MATERIAL

Abstract

The present invention relates to a crushing device comprising a jaw crusher provided with two jaws, at least one jaw of which moves reciprocally toward the other jaw and away from the other jaw in use, a supply device for supplying material to be crushed to the jaw crusher and a discharge device for discharging crushed material. The crushing device comprises a housing that encloses the jaw crusher, a ventilation device provided with air outlet openings that open into the crushing space, by means of which ventilation device air can be blown under pressure between the jaws of the jaw crusher device, and an exhaust device, which exhausts air mixed with fine material produced by the jaw crusher from the housing. The exhaust device is configured to convey the fine material mixed with the air to a collecting location. The invention further relates to a method for crushing material by means of such a crush device.

Claims

1. A crushing device configured to crush heterogeneous chunks of material, said crushing device comprising a crusher of the jaw crusher type provided with two jaws, at least one jaw of which moves reciprocally toward the other jaw and away from the other jaw in use so as to crush material that is present between the jaws, which jaws define a crushing space together with two bounding elements extending beside the jaws, parallel to the direction of reciprocation of the at least one jaw, a supply device configured to supply the material to be crushed to the jaw crusher and a discharge device configured to discharge material processed, which is at least partially crushed, by the jaw crusher, wherein the material flows from the supply device, through the crushing space, to the discharge device in a downstream direction of flow, wherein the crushing device comprises a housing that encloses the jaw crusher, at least one first ventilation device provided with an air outlet opening that opens into the crushing space, which ventilation device is configured to blow air under pressure between the jaws of the jaw crusher device and in upstream direction into the crushing space, and a first exhaust device which, in use, exhausts air mixed with fine material produced by the jaw crusher from the housing, wherein the exhaust device is configured to convey the fine material mixed with the air to a collecting location.

2. The crushing device according to claim 1, wherein the jaw crusher device is at least substantially hermetically sealed from the environment by the housing.

3. The crushing device according to claim 1 wherein at least one of the supply device and the discharge device is of the lock type.

4. The crushing device according to claim 1 wherein the air outlet opening is provided in a jaw or in a bounding element and opens into the crushing space, in a central part in a vertical direction of a jaw or a bounding element.

5. The crushing device according to claim 1 wherein the housing comprises one or more circumferential walls which define a cross-sectional area parallel to the horizontal at most five times greater than a perpendicular projection on a ground surface of the jaw crusher, with the jaws moved apart, and a discharge buffer device located downstream of the jaw crusher and upstream of the discharge device.

6. The crushing device according to claim 1 wherein at least one further ventilation device is provided, which further ventilation device is configured and disposed to blow air in upstream direction through material already crushed and/or to be crushed by the jaw crusher.

7. The crushing device according to claim 1 wherein at least one further exhaust device is provided, which further exhaust device is configured and disposed to exhaust air mixed with fine material produced by the jaw crusher from the housing.

8. The A crushing device according to claim 1 wherein an air pressure sensor is provided which is configured and disposed to measure the pressure prevailing in the housing.

9. The crushing device according to claim 1 wherein a flexible seal extends between at least one of the circumferential walls of the jaw crusher, comprising the jaws, and the housing, which seal separates a space provided with an inlet located above the crushing jaws of the jaw crusher from a space provided with an outlet located under the crushing jaws of the jaw crusher.

10. The crushing device according to claim 1 wherein an obstruction device is provided under an outlet of the jaw crusher.

11. The crushing device according to claim 1 wherein a hopper functioning as a discharge buffer device is provided under an outlet opening of the jaw crusher.

12. The crushing device according to claim 1 wherein a control device is provided which is configured to control the extent to which air is blown into the material by one or more ventilation devices to control the extent to which air is exhausted by one or more exhaust devices.

13. The crushing device according to claim 1 wherein a sensor is provided which is configured and disposed to analyse the quality of material exhausted by the exhaust device.

14. A method for crushing heterogeneous chunks of material into small parts and separating the same into discharge flows, comprising the steps of: a) providing a crushing device according to claim 1; b) supplying material to be crushed to a crushing space bounded by the jaws of the jaw crusher via the supply device; c) crushing material present in the crushing space while air is being blown into the crushing space by the ventilation device; d) exhausting fine material mixed with the air by means of the exhaust device and conveying said material to a collecting location; and e) discharging processed material from the crushing device via the discharge device.

15. The crushing device according to claim 2 wherein at least one of the supply device and the discharge device is of the lock type.

16. The crushing device according to claim 2 wherein the air outlet opening is provided in a jaw or in a bounding element and opens into the crushing space, preferably in a central part in a vertical direction of a jaw or a bounding element.

17. The crushing device according to claim 3 wherein the air outlet opening is provided in a jaw or in a bounding element and opens into the crushing space, in a central part in a vertical direction of a jaw or a bounding element.

18. The crushing device according to claim 2 wherein the housing comprises one or more circumferential walls which define a cross-sectional area parallel to the horizontal at most five times greater than a perpendicular projection on a ground surface of the jaw crusher, with the jaws moved apart, and a discharge buffer device located downstream of the jaw crusher and upstream of the discharge device.

19. The crushing device according to claim 3 wherein the housing comprises one or more circumferential walls which define a cross-sectional area parallel to the horizontal at most five times greater than a perpendicular projection on a ground surface of the jaw crusher, with the jaws moved apart, and a discharge buffer device located downstream of the jaw crusher and upstream of the discharge device.

20. The crushing device according to claim 4 wherein the housing comprises one or more circumferential walls which define a cross-sectional area parallel to the horizontal at most five times greater than a perpendicular projection on a ground surface of the jaw crusher, with the jaws moved apart, and a discharge buffer device located downstream of the jaw crusher and upstream of the discharge device.

Description

[0025] The present invention will now be described in more detail with reference to a schematic embodiment of the present invention as shown in FIG. 1.

[0026] FIG. 1 is a schematic view of a crushing device according to the present invention. The crushing device comprises two crushing jaws 1, which extend parallel to each other in vertical direction in FIG. 1. The two crushing jaws 1 are moved reciprocally toward and away from each other, in a manner that is known per se, by means of pivot arms 5, 6 in the form of eccentric shafts. During said reciprocal motion, the upper ends of the crushing jaws 1 are moved essentially away from each other by the upper pivot arms 6, whilst the lower ends of the crushing jaws 1 are moved toward each other by the lower pivot arms 5, and vice versa. The crushing jaws 1 move between a position as shown in FIG. 1 and a position in which the crushing jaws 1 converge from the top to the bottom to a more funnel-shaped configuration. In this way a crushing space of constantly varying diameter for receiving new material 7 to be crushed, which is supplied by the conveyor 23, is formed under an upper metering lock 2, which functions as a supplying device, by the crushing jaws 1 functioning as side walls 24 (of which only the side wall behind the crushing jaws is shown in the figure), whereupon the crushing jaws 1 move toward each other for crushing material present between the crushing jaws 1. During operation of the crushing device, material that is present between the crushing jaws 1 drops down while being crushed to an increasing extent. Disposed under the crushing jaws 1 is an obstruction device 10, in this case in the form of a plate 10 which extends horizontally under the crushing jaws 1, which obstruction device generates a partial obstruction of the through-flow. The obstruction device 10 causes the through-flow of the material between the crushing jaws 1 to slow down so as to improve the final result of the crushing device. Refer in this regard to the description of the method on page 8, lines 1-31 of International patent application WO 2011/142663 A1. Via the obstruction device 10, the crushed material flows into a receiving hopper 15 and subsequently through the rotary lock 3, which function as a discharge device, to a conveyor 16, which discharges the crushed material 8 for further processing. With the exception of an inlet opening 17, into which the metering lock 2 opens, and an outlet opening 18, which opens into the metering lock 3, the jaw crusher with the hopper 15 is entirely enclosed by a housing 13. The housing 13 is a rectangular block shape of circumferential walls of steel plate, in which the rotary locks 2 and 3 are integrated. The housing 13 may be supported on standards or the like. Shown within the housing 13 is an upper chamber 19, which is bounded by part of an upper wall of the housing 13, a vertical partition 20 and a flexible wall 4 which extends between the vertical partition 20 and the crushing jaws 1. The wall 4 is of the accordion type and is connected to the static vertical partition 20 on one side and to the reciprocating crushing jaws 1 on the other side. A discharge channel 21 connects to the upper chamber 19, to which discharge channel an exhaust device 12 is connected, which exhaust device generates an underpressure in the discharge channel 21 relative to the prevailing pressure in the upper chamber 19 for the purpose of exhausting the mixture of air and light particles 9 in a direction P1. In use, air is blown through air outlet openings 25 into the space between the crushing jaws 1 via ventilation devices P3. As a result, fine particles 9 are blown out of material that is present between the crushing jaws 1, whilst in addition a relative overpressure is created in the upper chamber 19. Because air is withdrawn from the chamber 19 through the discharge channel 21 in the exhaust direction P1, an air flow is created from the space between the crushing jaws 1 to the discharge channel 21, in which air flow light particles 9 are carried along. When the crushing device is used for crushing concrete, said light particles are in particular relatively light particles of hydrated cement, which are led to a discharge location (not shown) or a collecting location in the form of a silo (symbolically indicated at 27) via the discharge channel 21. In said silo, the hydrated cement is connected.

[0027] In this exemplary embodiment, air is also blown into the crushed material collected in the hopper 15 via the air inlets P3 in the wall of the hopper 15. Exhaust devices 12 are provided above the hopper 15, at the location where crushed material flows into the hopper 15 via the obstruction device 10, which exhaust devices exhaust air mixed with fine particles 9 as fine material from the crushed material via a discharge channel 22, in a similar manner as with the discharge channel 21, and carry said material to the discharge location (not shown) in the form of a silo. Small particles 9, particles of hydrated cement in the case of concrete being crushed, carried along with the flow of material between the crushing jaws 1 in the direction of the obstruction device 10 and the hopper 15, can thus be removed from the crushed material yet. The crushed material, from which a large portion of the small particles, small particles of hydrated cement in the case of concrete being crushed, has been removed, flows into the metering lock 3 via the hopper 15 and is conveyed ahead on the conveyor 15 for further processing. In FIG. 1, the conveyor 23 is positioned above the metering lock 2 in such a manner that material that drops from the conveyor 23 into the metering lock 2 will automatically cause the metering lock 2 to rotate under the influence of the force of gravity. It will be understood that the metering lock 2 is configured so, that leakage of air from the chamber 19 to outside the housing 14 is minimised by using a relative overpressure. Likewise, the hopper 15 is positioned in such a manner relative to the metering lock 3 that crushed material 8 that finds its way from the hopper 15 into the metering lock 3 will automatically set the metering lock 3 moving. The crushed material collected in the hopper 15 and also the metering lock 3 restrict any flow of air from inside the housing 13 to outside the housing 13. Pressure sensors (P1C1, P1C2) are provided both inside and outside the housing 13, which sensors measure the local air pressure on the basis of which the air inlets P3 and the air exhaust devices P1 can be controlled.

[0028] In the figures and the above description thereof, the present invention is shown and described with reference to only one embodiment of a crushing device according to the present invention. It will be understood, however, that many variants, which may or may not be obvious to the skilled person, are conceivable within the scope of the present invention as defined in the appended claims. Thus, in particular the crushing of concrete and the associated separation of hydrated cement (stone) are discussed in the exemplary embodiment. It is also possible, however, to crush other materials, for example slag, using a crushing device according to the present invention, with other particles, such as fly ash particles, for example, being exhausted by means of the exhaust devices. Furthermore, the description concerns a specific jaw crusher device which is in particular configured for selectively crushing concrete. Of course it is also possible within the scope of the present invention to use other types or versions of jaw crushers. The supply of material to be crushed and/or the discharge of crushed material can be realised by means of lock types other than rotary locks. If use is made of an overpressure within the housing relative to a prevailing pressure outside the housing, open communication between the space inside the housing and the space outside the housing, for example via an inlet or outlet opening, is preferably prevented. In the figures, specific locations for the supply and exhaust of air are indicated. It will be understood that these positions can be adapted to a specific situation in dependence on the use and the air flows to be expected.