Patent Grant
8763813
This invention concerns an apparatus for the transport and sorting of loose materials, especially abrasives in manufacturing operations in which the surfaces of products are cleaned or ground—metal castings, for example. The invention solves the need for removal of already used and soiled abrasive material from the work place, the removal of impurities from the used abrasive materials, and the preparation of the cleaned abrasive material for re-use, all while maintaining a structural height of the apparatus that is as low as possible, and with minimal installation requirements.
Some manufacturing plants use loose abrasive materials for cleaning and grinding the surfaces of semi-finished products such as metal castings. Floor conveyors, worm conveyors, vibration conveyors, bucket elevators and integrated cleaning equipment, connected to containers, are used for the collection and sorting of such loose materials. The most common type of floor conveyor used is a rake conveyor with a horizontal plane surface which rakes with reciprocal movement above the horizontal surface; the rakes are attached to a supporting frame, which reciprocates in the horizontal direction. The driving units of known rake conveyors are located on the plane of the equipment. The workplace floor is located above the rake conveyors, and the floor consists of a supporting grate with mesh size of around 35×35 mm.
The disadvantage of these rake conveyors is that the abrasive material is either not actively removed from the places where the driving units are located, or the drives are located in rooms adjacent to the workplace, which increases space requirements. Other disadvantages of the existing systems are the difficult installation of rake conveyors using several drives and the fact that with the equipment described above, some small parts that are long and thin may fall through the supporting grate. This leads to parts accumulating on the floor of the workplace, e.g. screws or pieces of wire which may get stuck and cause the rake conveyor to fail.
Other existing systems contain two perpendicular conveyors that work on two planes (called a “lengthwise conveyor” and a “cross conveyor”), or in rare cases on one plane. A lengthwise conveyor is usually located above the cross conveyor, and the cross conveyor transports the loose material into a bucket conveyor outside the workplace. The disadvantages of these systems are the decreased load capacity of the floor at places where the conveyors cross and the unequal footing depth and increased costs for the construction of the foundation.
Worm conveyors are also utilized for horizontal transportation. The disadvantage of these conveyors is the difficult extension of worms to lengths exceeding 6 m, as the worms tend to sag at longer lengths. Another disadvantage of worm conveyors is doubled energy consumption in comparison to rack conveyors and the more expensive structural preparation of the floor.
Vertical bucket conveyors are typically connected to horizontal conveyors. The disadvantage of the connection to rack conveyors with a horizontal underlay surface is that when the bucket conveyor is connected to a rack conveyor at the same level, some spaces can occur from which the abrasives cannot be taken up by the bucket conveyor. On the other hand, a design in which the bucket conveyor is connected at a level lower than the rack conveyor requires other structural adaptations.
Vibration conveyors are also utilized for horizontal transportation. Their disadvantage that the building has to be tall to accommodate such a conveyor, which is unfavourable especially at long distances.
The bucket conveyors used in the past in air blasting are exclusively a single-row type. The use of a single-row type of bucket conveyor requires a large transportation height because of the column arrangement of the following equipment such as cleaners, silos, blasting equipment, etc. In such cases, the total height of the conveyors is about 3 m higher than in the system of the invention, and their structure sometimes reaches into the higher floors of the building or even above the roof structure. Another disadvantage is the necessity of installing the lower part of the bucket conveyor under the floor level. Because the belt is long, it stretches, which requires more frequent checking and tightening of the belt.
Double-row bucket conveyors are known from the design of sweeping machines, where it is used for connecting the input and output worm conveyors with the integrated cleaning apparatus for abrasives. The disadvantage of this design is that it cannot be used in workplaces where the large-area collection of abrasives is required in connection with blasting by pressurised air.
The disadvantages mentioned above are solved by an apparatus for transport and sorting of loose materials, consisting of a rack conveyor with a horizontal moveable part connected to a linear drive, and equipment for the sorting of loose material. The essence of this invention is that the rake conveyor further comprises an additional rotating-swinging part and/or a diagonal part. The apparatus also comprises a first bucket conveyor, which is located between the rotating-swinging part and/or the diagonal part of the rake conveyor and the equipment for sorting of loose materials. At least one of the outputs of the equipment for sorting of loose material is alternatively followed by a second bucket conveyor. According to another alternative, the driving wheels of the first and second bucket conveyors are arranged on one common driving shaft. Under other alternatives at least one of two or more screens is located above at least part of the rake conveyor, or the linear drive of the horizontal movable part of the rake conveyor is located above the horizontal movable part of the rake conveyor. In another alternative the second bucket conveyor and the first bucket conveyor together create a dual bucket conveyor. The buckets of the dual bucket conveyor can be arranged in two parallel rows on one common belt. The apparatus can also involve a silo, which can be advantageously located next to the equipment for sorting of loose material and in the process the second bucket conveyor or the dual bucket conveyor is equipped with an outlet for connecting to the silo. According to another alternative, the apparatus is further equipped with a container. In the process the silo is equipped with an outlet mouth leading into the container and the container has an outlet, which leads into the output of the first bucket conveyor or into the first input of the dual conveyor or the outlet of the container leads above the rake conveyor. The outlet of the container can advantageously lead above the rotating-swinging part or above the inclined part.
An advantage of the apparatus according to this invention is low structural height and minimal requirements for excavation. Another advantage is the possibility to use more than one driving unit, offering longitudinal adjustment of the rake strips without any limitation of their total length. Another advantage of the apparatus is its low failure rate. If the apparatus is used for the collection and cleaning of abrasives, the collected abrasive material is pre-cleaned before being discharged to the rake conveyor. Another advantage is that the rake conveyor rakes through its entire area, which is enabled by the arrangement of driving units located above the rake frame; the active flights also rake the area under the drives located inside of the workplace. The area taken up by the rake conveyors does not exceed the area from which the loose material is being collected. An advantage of the use of the container is that the silo does not need to be large or, above all, high, even in the case where a very uneven operation is expected; as such, the arrangement ensures a low structural height. In the case of uneven operation, the passage of the abrasive material through the apparatus becomes more even, as the immediate excess amount of abrasives is returned back in front of the input into the equipment for cleaning the abrasives.
The apparatus of this example is intended for the collection, cleaning and storage of loose material, in this case abrasive materials used for cleaning steel castings by blasting. Referring to
The apparatus under this example works as follows: the surface of a metal casting is cleaned by blasting by abrasives using pressure blasting equipment. The used abrasive material falls onto floor 5 of the workplace together with the released iron scales and other impurities, where it falls through the holes in grates 52. Particles of the removed impurities and the used abrasives are deposited at the horizontal part of base 111 of rake conveyor 1 and are transported gradually over the surface of the base 111 by the reciprocating movement of flights 113 towards the cylindrical part of base 111, which is located under the rotating-swinging part 12 of rake conveyor 1. Arm 121 is in contact with frame 112 of the horizontal part of rake conveyor 1 and due to the reciprocal movement of the frame 112 it performs the reciprocal-swinging movement about its rotational axis. Flights 113 located at the circumference of the arcuate part 122 move the abrasives gradually over segment 123 of base cylindrical surface of the base 111, while the abrasive material moves upwards above input 31 of the first bucket conveyor 3. Through the first bucket conveyor 3, the mixture of used abrasives and impurities is transported to the first chamber 25 of equipment 2 for sorting loose material, and on inclined vibrating screen 251 the remaining coarse impurities are separated. The mixture that is now free of coarse impurities falls through the first slit 253 into the second chamber 26. During their free fall, the particles move along the second slit 263, through which the air drawn from the ambient environment reaches the third chamber 27 in a direction, which is perpendicular to the movement of the particles of the mixture. The smallest and lightest particles of the mixture are carried away on the air stream into the third chamber 27, where most of the particles are deposited due to decreased air velocity. The air is exhausted from the third chamber 27 through outlet 271. The abrasive material, now free of both coarse impurities and fine particles, is deposited in the second chamber 26, from which it is taken through second output 22 to input 41 of second bucket conveyor 4, which raises it to the first input 61 of silo 6. From silo 6, the cleaned abrasive material is taken out for the further use through its second output 63 and pressure valve 71 into pressure blasting equipment 7. Since pressure blasting equipment 7 works under pressure, the input of the pressure blasting equipment 7 is closed by pressure valve 71 during the operation. During uneven operation the abrasives can accumulate in silo 6. To avoid clogging of the second bucket conveyor 4 with the collected abrasives, silo 6 is equipped with outlet mouth 62, through which the excess abrasives falls into container 9. If the level of abrasives in the system with container 9 decreases, the required abrasive material fills up through valve 92 and through input 31 of first bucket conveyor 3 back to the system. Because the used abrasive material is depleted during operation, new abrasive material is added as necessary into container 9 through filling hole 96 after lid 93 has been raised. The machine operator adds new abrasives into container 9 as necessary.
As will be discussed in some detail below, the apparatus of example 2 (shown in
The apparatus under example 2 works in the same way as the apparatus, described in example 1, with the only difference being that the abrasive material from outlet 91 of container 9 is diverted (by a configuration not apparent from
The apparatus of example 3 is much like that of the apparatus described in example 1, except that first and second bucket conveyors 3, 4 are replaced by dual bucket conveyor 45 as described in example 2.
Perspective Views
Turning to
From this figure the alert reader may more fully appreciate the many benefits of the invention. The entire flow path of the loose material fits easily within a relatively small footprint, does not require excavation or installation of equipment below an existing floor, and does not stick up too high (and thus does not require a high ceiling).
The apparatus according to this invention can be used for collecting and sorting loose materials such as abrasive grit and small balls, sorting grain from weeds and stones, sorting crushed stones into fractions, etc. Thanks to the modular design and small installation dimensions, the apparatus can be installed into transport containers, with the individual containers arranged into assemblies according to particular customer requirements and taking advantage of the described variable possibilities.
Table 1, which is part of the specification and which follows, provides in tabular form a list of reference numerals for the convenience reference of the reader.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-2 | Jan 2011 | CZ | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5575427 | Karpisek | Nov 1996 | A |
| 5577618 | Rafferty | Nov 1996 | A |
| 20030146315 | Boast | Aug 2003 | A1 |
| 20050040015 | Schlegel et al. | Feb 2005 | A1 |
| 20100193618 | Lewis-Gray | Aug 2010 | A1 |
| 20110073529 | Sprouse et al. | Mar 2011 | A1 |
| 20120138426 | Cruz | Jun 2012 | A1 |
| 20130000933 | Neuwirth | Jan 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| 2474361 | Jul 2012 | EP |
| Number | Date | Country | |
|---|---|---|---|
| 20120168355 A1 | Jul 2012 | US |
