EP1754550B1 - Air jet device - Google Patents

Description

The present invention relates to an apparatus for blowing over a free fall distance or a link belt conveyed individual pieces of a stream of material with a gaseous medium, comprising at least one inlet opening for the gaseous medium, and a plurality of blowing nozzles, via which controls the gaseous medium to predetermined individual pieces of material flow is blown, as well as the Anblasdüsen associated valves, preferably solenoid valves through which the Anblasvorgang is triggered or stopped.

Such devices are used in sorting machines for transparent and non-transparent bulk materials such as metals, plastics, rocks and glass, paper or cardboard. They work preferably by means of optical or inductive transmitter and receiver units and serve to remove foreign matter located in the material flow from the material flow or to convey different types of the material of the material flow into different containers.

Such a sorting machine is for example from the AT 395,545 B known. The transmitter units consist for example of light rays emitting light sources, preferably diode light sources, which are bundled in the receiver unit via a lens system on a photocell.

However, embodiments are also known in which color cameras are used as receiver units and conventional light sources such as fluorescent tubes function as light sources.

Both transmitter and receiver units are connected to a central processing unit which controls the incoming Data processed and it due to the intensity of the incident on the receiver unit and emitted by the transmitter units light beams to detect location, size and type of individual pieces located in the material flow.

Subsequently, the sorting of the individual pieces is carried out in dependence on the successful detection of the individual pieces in the material flow. This takes place in a manner known per se by blowing the individual pieces by means of a gaseous or liquid medium, for example compressed air or water, during their free fall or during their transport on a link belt through the gaps of the link belt, whereby these from their trajectory or . Are deflected from the material flow lying on the link belt in a designated container.

In known sorting machines serves as a blowing the Anblasdüsen and leading to the Anblasdüsen flow channels containing component to which commercial acquirable solenoid valves are coupled, preferably screwed, whereby the Ventilauslassöffnung or the Ventilauslassöffnungen are connected to corresponding component provided on the input openings of the device to establish a connection to the blowing nozzles.

The coupling of the solenoid valves to the component containing the Anblasdüsen can not be done in any position. A conventional solenoid valve usually consists of a valve stem and a return spring, to reset the valve stem and an electromagnet, which causes the opening movement of the valve stem. Return spring and solenoid are, due to the operation of the valve, each seen on different sides of the valve stem with respect to the axis thereof, arranged. This only results in a very Limited arrangement possibility of the solenoid valve on the component containing the Anblasdüsen.

When using such known Anblasvorrichtungen has been found that the response or in other words the response time of the Anblasdüsen is in need of improvement due to the coupled construction. Reason for this are the long flow channels, which arise due to the connection commercially available solenoid valves, to which the Anblasdüsen having component. Overall, this results in long, from the valve to the Anblasdüsen leading flow channels, causing on the one hand large pressure losses and thus already requires a higher output pressure for exact blowing of the individual pieces in the material flow from the beginning and on the other hand also leads to a long "Nachblasen" after switching off the valve , which not only means an increased consumption of the gaseous medium but also a reduction in the sorting efficiency of the sorter.

But it is not only the length that causes the pressure loss in the known Anblasvorrichtungen, but also the required number of deflections, which passes through the gaseous medium to get from the valve seat to the Anblasdüsen and which due to the limited connectivity options of commercially available solenoid valves give the the Anblasdüsen having component. Each individual deflection causes an additional pressure loss. Considering that the gaseous medium used to date in the present technical field is compressed air, there is also a financial disadvantage in conventional blowing devices, since compressed air is one of the most expensive consumables and thus reducing the compressed air requirement and the required pressure not only technical Benefits such as smaller components and shorter reaction times but also savings financial nature due to the lower consumption of compressed air.

A further disadvantage of the known blowing devices is the fact that several of the commercially available solenoid valves have to be arranged on the component having the blowing nozzles. Due to a required minimum flow volume limits are set here as far as the size of the valves is concerned. A minimum size adapted to the respective field of application must not be undercut. However, each of the commercially available valves has its own housing with wall thickness, so that valuable space is lost on the Anblasdüsen having component by this wall thickness, whereby the number of usable valves is unnecessarily limited to a component having the blowing opening. In addition, commercially available valves must not be installed directly adjacent to each other to allow circulation of cooling air to the valve body.

From the DE 28 48 000 A1 For example, a flow divider for ore grading machines is known wherein ore rocks are passed by free-fall nozzles and selectively deflected. This is an elongated metal block with a polygonal cross-section, which has on one side a plurality of, each at an obtuse angle abutting surfaces for receiving valves, wherein the Anblasdüsen are provided on an opposite, flat side of the metal block. The flow divider has along its longitudinal axis a central fluid supply line through which the valve chambers adjacent to the objective surfaces are fed via paired fluid transmission lines. Each of the valve chambers has a flow channel extending transversely through the entire metal block and through the fluid supply line to the Fluid outlets. In order to achieve a linear juxtaposition of the fluid outlets along the metal block in spite of the angular arrangement of the valve chambers, one of the fluid outlet lines is straight and the other two are provided with a small curvature. These blowing device designed by the complicated feed of the valve chambers by means of the paired fluid transmission lines together with the completed in the case of Ausblasdüsenbetätigung 180 ° deflection of the flow medium in the direction of the flow channel as very complex, takes up much space and still requires a considerable friction or pressure loss of the system. In particular, the long flow channels, which are passed through the cross section of the central fluid supply line and there are exposed to abrasion by the flow medium, prove to be disadvantageous in the present application.

It is therefore an object of the present invention to avoid the mentioned disadvantages and to provide a device of the type mentioned above, on the one hand allows a shortening of the reaction time of the Anblassvorrichtung, while lowering the required pressure and reducing the pressure losses occurring.

It is a further object of the present invention to provide a device of the kind set forth which reduces the space requirement of the valves and thus enables the arrangement of more valves compared to the blowing devices known from the prior art, while maintaining the overall space requirement.

Another object of the invention is to reduce the number of parts required to manufacture such an inflator.

This is achieved by the characterizing features of claim 1 according to the invention.

A device for blowing over a free-fall line or a link belt conveyed individual pieces of a material flow with a gaseous or liquid medium comprises Anblasdüsen including associated valves, wherein between each Anblasdüse and the valve seat of a Anblasdüse associated valve, a flow channel is provided which only a single deflection of the gaseous or liquid medium causes.

By the valve stem of the valve according to the invention is arranged substantially perpendicular to the Anblasdüse or α encloses an acute angle α with the axis of the Anblasdüse, a space-saving and structurally particularly easily executable variant of a blowing device according to the invention, while maintaining the requirement that the working medium on its way from the valve seat to the blowing nozzle only once deflected proposed. In a preferred embodiment, the valve stem of the valve with the axis of the Anblasdüse forms an acute angle α in order to better respond to the prevailing space conditions and to facilitate accessibility to the device.

In this way, the pressure loss remains low and the reaction time can be kept correspondingly low. On the other hand, this also an optimal arrangement of the valves is possible.

According to the characterizing features of claim 2, the blowing device according to the invention is operated with compressed air or water.

The characterizing features of claim 3 provide that a valve several Anblasdüsen are assigned. The number of blowing nozzles determines the resolution or the accuracy with which individual pieces can be blown out of the material flow. By controlling multiple Anblasdüsen by means of a valve a simplified control is possible.

According to the characterizing features of claim 4 it is provided that each valve is associated with exactly one Anblasdüse. This variant makes it possible, with a given number of blowing nozzles, to achieve the highest resolution or blowing precision.

The Anblasdüsen, the valve stem including the valve seat, and the at least one inlet opening, and the flow channels, which establish a connection between the respective valve seats with the respective Anblasdüsen are housed according to the characterizing features of claim 5 in a single housing. As a result, a particularly compact design of a blowing device according to the invention can be achieved. The wall thicknesses of commercially available solenoid valves fall completely away, so that with the same flow rate of the valves much less space is required.

According to a further preferred embodiment of the invention as described in claim 6, the Anblasdüsen are covered with a removable bar, which has eccentric or concentric bores to the Anblasdüsen. Wear or contamination caused by contact of the blowing device with the flow of material can thereby adversely affect the operability of the blowing device according to the invention, since, before such a condition occurs, the bar can be replaced by a new one. The actual, arranged in the housing Anblasdüsen are neither worn nor dirty.

Due to the eccentric arrangement of the holes, the medium used can be distributed after leaving the Anblasdüsen along the bar without increasing the number of Anblasdüsen, whereby the Anblasauflösung can be increased overall.

According to the characterizing features of claim 7, it is provided that at least for a defined number of Anblasdüsen the distance between the opening of an Anblasdüse the associated valve seat is at most 16 mm. As a result, depending on the size of the blowing device, a particularly short reaction time can be made available, at least for a defined number of blowing nozzles.

Fig.1

eine axonometrische Ansicht einer erfindungsgemäßen Anblasvorrichtung

Fig.2

eine Frontansicht einer erfindungsgemäßen Anblasvorrichtung

Fig.3

eine Schnittansicht einer erfindungsgemäßen Anblasvorrichtung entlang Linie A-A aus Fig.2

Fig.4

eine Schnittansicht einer erfindungsgemäßen Anblasvorrichtung entlang Linie D-D aus Fig.2

Fig.5

eine Schnittansicht einer erfindungsgemäßen Anblasvorrichtung entlang Linie B-B aus Fig.2

Fig.6

eine schematische Darstellung einer aus dem Stand der Technik bekannten Sortiervorrichtung

Fig.7

eine Schnittansicht einer alternativen Ausführungsform einer erfindungsgemäßen Anblasvorrichtung

Following is now a detailed description of the invention with reference to drawings. It shows

Fig.1

an axonometric view of a blowing device according to the invention

Fig.2

a front view of a blowing device according to the invention

Figure 3

a sectional view of a blowing device according to the invention along line AA Fig.2

Figure 4

a sectional view of a blowing device according to the invention along line DD Fig.2

Figure 5

a sectional view of a blowing device according to the invention along line BB Fig.2

Figure 6

a schematic representation of a known from the prior art sorting device

Figure 7

a sectional view of an alternative embodiment of a blowing device according to the invention

Fig.1 shows an axonometric view of a blowing device according to the invention. This consists of a housing 1, on which electromagnet 2, are held, and a replaceable bar 3, which will be discussed in more detail below.

The housing is preferably made of aluminum. However, alternative materials such as steel, stainless steel, brass or plastic can also be used.

Fig.2 shows a front view of the blowing device according to the invention with a view towards the bar. 3

How out Figure 3 it can be seen which is a sectional view taken along the line AA Fig.2 shows, the housing 1 in its interior a plurality of cavities 4, which each serve to receive a valve. Each valve is constructed from a valve stem 5 and a return spring 6. Furthermore, two seals (0-rings) 7, 8 and an abutment 28 also form constituents of the valve and the electromagnet 2 arranged outside the housing 1 and causing the movement of the valve stem 5.

The housing 1 further comprises inlet flow channels 9, 10, 11, 12, 13 (see FIG Figure 4 ), via which the gaseous working medium, preferably compressed air, is passed from a connection opening 15 to the valves, as well as flow channels 14, 24 (see FIG Figure 5 ), which lead from the respective valve seats 19 to the associated Anblasdüsen 16. These flow channels are composed of a section which forms the outlet nozzles 16 and a section 20 which adjoins directly the valve seat 19 and thus, as viewed from the injection nozzles 16, follows the deflection from the latter to the valve seat 19.

Before the Anblasdüsen 16, a strip 3 is arranged, which is connected via screws 18 interchangeable with the housing 1. The strip 3 has holes 17 which are arranged in the mounted position of the strip 3 eccentrically to the Anblasdüsen 16, so that the Anblasdüsen 16 leaving medium can be distributed along the bar 3, whereby the Anblasauflösung increases.

Alternatively, the arrangement of the holes 17 can also be made concentric to the Anblasdüsen 16, whereby, however, the number of holes 17 is limited to the number of Anblasdüsen 16.

Each flow channel 14,24 between the Anblasdüsen 16 and the valve seat 19 has only a single deflection, which by the transition from the Anblasdüse 16 forming portion of the flow channel 14,24 in those immediately adjacent to the valve seat 19 portion of the flow channel 14,24 is formed. Pressure losses and reaction time can be reduced by the fact that the gaseous working medium experiences only a single change of direction. At the same time is ensured by the inventive arrangement of the valve stem 5 is substantially perpendicular to the exhaust nozzles 16, that the valve construction can be very easily installed in the housing 1, wherein the required electromagnet 2 and the return spring 6 axially arranged on different sides of the valve stem 5 are.

Figure 6 shows a schematic representation of a known from the prior art sorting device, in which genus same blowing devices are used. In this case, a subsequent to a task station 29 slide 21 is provided in the lower region of a transmitter units 22 and receiver units 23 and a central processing unit (not shown) existing Detector device is arranged for detecting individual pieces in the material flow. This detector device controls an arranged at the end of the chute 21 blowing device 25, which are arranged below the following in this area the course of a parabola material flow and upon activation, the desired individual pieces (foreign bodies, foreign varieties, etc) deflect upwards, so that they in one provided container or containers 26 are transported.

Figure 7 shows a sectional view of an alternative embodiment of a blowing device according to the invention. This corresponds in the essential features of those in Figure 5 shown device, but with the difference that the valve axis 27 and the valve stem 5 with the axis of the Anblasdüsen 16 include an acute angle α, where α can be both positive and negative, ie in Figure 7 the valve stem 5 can tilt to the left or to the right. Depending on the space required, the installation of the device according to the invention can be facilitated in this way.

The operation of the blowing device according to the invention is as follows:

Via the connection opening 15, the working medium is conducted into the housing 1, where it is first distributed via the inlet flow channel 9 into the inlet flow channels 10, 11, 12 and 13 until it has reached the respective valve seat 19 of the individual valves. These are closed at this time, ie. Each valve plunger 5 closes tightly with the valve seat 19. Depending on a control signal of a central processing unit, which in turn is based on a detection of individual pieces to be sorted out in the material flow, the electromagnets 2 are activated whereby the valve tappets 5 move and the valve opens. The gaseous working medium can now flow to the Anblasdüsen 16, where it is deflected once.

Claims (7)

1. A device for blowing against individual pieces of a material flow conveyed via a freefall path or a link conveyor using a gaseous or liquid medium, comprising at least one connection opening (9) for the gaseous or liquid medium, as well as multiple blowing nozzles (16), via which the gaseous or liquid medium is blown in a controlled way on predetermined individual pieces of the material flow, as well as valves, preferably solenoid valves, assigned to the blowing nozzles (16), through which the blowing procedure is triggered and stopped, a flow channel being provided between each blowing nozzle (16) and the valve seat (19) of the valve assigned to a blowing nozzle (16), which only causes a single deflection of the gaseous or liquid medium, characterized in that the valve plunger (5) of the valve is situated essentially perpendicularly to the blowing nozzle (16) or encloses an acute angle α with the axis of the blowing nozzle (16).
2. The device according to Claim 1, characterized in that the gaseous/liquid medium is compressed air/water.
3. The device according to Claim 1 or 2, characterized in that multiple blowing nozzles (16) are assigned to one valve.
4. The device according to one of Claims 1 through 2, characterized in that one blowing nozzle (16) is assigned to each valve.
5. The device according to one of Claims 1 through 4, characterized in that the blowing nozzles (16), the valve plunger (5) together with valve seat (19), as well as the at least one connection opening (9) and the flow channels, are housed in a single housing.
6. The device according to one of Claims 1 through 5, characterized in that the blowing nozzles (16) are covered by a replaceable strip (3), which has eccentric or concentric holes (17) to the blowing nozzles (16).
7. The device according to one of Claims 1 through 6, characterized in that, at least for a defined number of blowing nozzles (16), the distance between the opening of a blowing nozzle (16), and the assigned valve seat (19) is at most 16 mm.

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