EP2571657A1

EP2571657A1 - Method and device for conveying and metering bulk material in vacuum suction blasting

Info

Publication number: EP2571657A1
Application number: EP11735773A
Authority: EP
Inventors: Gerd Pieper
Original assignee: Pieper Innovationsgesellschaft mbH
Current assignee: Pieper Innovationsgesellschaft mbH
Priority date: 2010-05-17
Filing date: 2011-05-16
Publication date: 2013-03-27
Anticipated expiration: 2031-05-16
Also published as: EP2571657B1; DE102010020691B4; DE102010020691A1; DK2571657T3; WO2012019576A1

Abstract

The invention relates to a method for conveying and metering bulk material, for example blasting agent, welding flux, coating agent, or the like, during the processing, connecting, or coating of surfaces by means of vacuum suction blasting, wherein the bulk material is kept ready in a reservoir (5) placed under vacuum (p_uB) by a suction unit (2), the bulk material is conveyed from said reservoir to an injection blasting lance (14) through a hose line (3), accelerated there by an atmospherically suctioned foreign air flow and directed at a processing surface (1) kept under vacuum (p_uB) by a jet hood, suctioned out of the jet hood (14), then fed to a separating unit (4) for cleaning and conveyed back into the reservoir (5) so that the bulk material can be circulated. The aim of the invention is to provide a method and device for conveying and metering bulk material, wherein the conveying, transporting, and metering are possible exclusively under vacuum while the method processes and the assemblies for the reservoir and the metering are simplified, the operational reliability is increased, and costs are saved. Said aim is achieved in that a suction flow is produced by means of an injection metering pipe (9) immersed in a removal area (7) of the bulk material in order to remove and meter the bulk material, the vacuum (p_D) of said suction flow being set, by suctioning an air flow (L_D) at least under atmospheric pressure or vacuum as transport air, to a value that is greater than the vacuum (p_UB) in the jet hood (14) or in the reservoir (5), wherein the removal amount or metering amount of the bulk material is set by means of the vacuum difference (Δp), present between the blasting lance (14) and the injection metering pipe (9), of the suctioned air flows (L_D; L_ST) of the injection metering pipe (9) and of the blasting lance (14).

Description

Method and device for conveying and metering bulk material during vacuum suction blasting

Description: The invention relates to a method for conveying and metering bulk material, for example blasting agents, welding powder, coating agents or the like, during processing, bonding or coating of surfaces by means of vacuum suction blasting, in which the bulk material is placed under vacuum in a suction unit Reservoir kept ready, transported by this the bulk material via a hose line to an injection jet, accelerated by an atmospheric sucked foreign air stream and directed to a held by a jet hood under vacuum processing surface, sucked from the jet hood, then fed to a separation unit for cleaning and in the Reservoir is transported back so that the bulk material can be circulated.

BESTATIGUNGSKOPIE The invention further relates to an apparatus for performing the method, - with at least one reservoir for receiving a loose bulk material, a separation unit for cleaning the bulk material, a suction unit connected to the separation unit for generating a negative pressure in the reservoir, one connected to the reservoir Hose feed line for transporting the bulk material into an injection blasting lance guided to a blasting hood set under negative pressure for

Acceleration of the bulk material by sucked by the injection beam lance, at least at atmospheric pressure air flow in the direction of a processing surface and connected to the jet hood hose discharge for sucking the bulk material and the removed particles from the jet hood in the separation unit and zurückbefördern into the reservoir.

State of the art

From DE 101 02 924 Cl is a method for beam processing, in particular dimensionally accurate removal and / or compaction and / or coating of solid surfaces, such as removal of paint defects from Lackierflächen, smoothing of solder and welds, removal of contaminated concrete layers or Known rust layers, hardening, leveling or coating of metal surfaces, in which a blasting agent in a vacuum-generated Tragluftstrom metered by gravity and / or injector, transported in a hose system to a jet lance and directed through a blasting chamber under negative pressure processing surface, from there into the air flow back, cleaned and possibly circulated, wherein the acceleration of the blasting agent is generated by the negative pressure and the blasting chamber is shifted from the processing surface to the processing surface. The blasting agent is given at least one additional energy pulse by at least one further sucked by the negative pressure, at least atmospheric pressure gas stream to achieve a lying well above the flow velocity of the carrier air flow end velocity, with the energy input into the surface to be processed depending on the parameters, type and shape the working surface and the blasting agent, degree of loading of the carrier air stream with blasting agent, negative pressure in the carrier air flow, blasting time and

Beam temperature is set.

This known method operates with a storage container for the blasting material in which a plurality of bulk hopper are arranged one above the other, which are pneumatically separated by closing members such as flaps, valves or valves. The blasting agent passes by gravity from these bulk hoppers in the metering device, which is under normal pressure. There are therefore separate vacuum and normal pressure ranges that complicate the promotion, transport and dosing of the blasting agent in the process significantly and increase the cost of a vacuum aspirator. In addition, the interfaces between the various pressure areas within a plant are often vulnerable, because blasting agents of different types and shapes are used, which complicate a pneumatic separation. Furthermore, the juxtaposition of underpressure and overpressure always leads to Pressure losses, which must be compensated by a corresponding dimensioning of the suction unit.

task

In this prior art, the present invention seeks to provide a method and apparatus for conveying, transporting and dosing of bulk material, for example blasting abrasive, welding powder,

Coating agent o. The like. To provide when processing, bonding or coating surfaces by vacuum suction, in the conveying, transporting and dosing exclusively in vacuum while simplifying the procedures and assemblies for the reservoir and the dosage, increasing the reliability and economy of costs becomes possible.

This object is achieved by a method of the type mentioned with the features of claim 1 and by a device with the Merkmaien of claim 7. Advantageous embodiments of the method and the device are the dependent claims.

The inventive solution is based on the

Awareness of laying the dosing process in the vacuum range, so that the conveying, transporting and dosing of the blasting agent can be carried out within a completely held under negative pressure circuit.

This is achieved by having one in one A suction flow for the removal and metering of the blasting agent is generated, the negative pressure is set by sucking an at least under atmospheric pressure or negative pressure air flow as transport air to a value which is greater than the negative pressure in the jet hood or in the Reservoir, wherein the removal and metering of the blasting agent by means of the rule between jet lance and In dosing metering

Subpressure difference of the intake air flows of

Injection metering tube and jet lance is set. Of particular advantage is that the bulk material bed is stored on a conical bottom in the reservoir in the tube-like, bottom closed removal area, the bulk material brought together by gravity and the bed height above the removal area almost a maximum value, wherein the injection metering tube generated by the injection Suction flow for removal and metering of the blasting medium is directed into this area. The removal area is sealed off from the separation unit by the bulk material charge arranged above it by a sufficiently large pad of bulk material, whereby two different levels of underpressure within the storage container can function safely next to one another. In a preferred embodiment of the method according to the invention, the bulk material bed is loosened in the removal area by an atmospheric external air flow, which is associated from the outside with a fluidizing tube or by a removal region Air admission hole is directed into the removal area. A further embodiment of the method according to the invention provides that the bulk material is loosened in the removal area by a removed from the suction air of the separation unit air flow, which is directed with a connected via an inlet cone in the separation unit Pitot tube in the removal area.

In a further embodiment of the method according to the invention, the negative pressure at the injection metering tube to values between 30 to 350 mbar, preferably 200 mbar and the negative pressure in the reservoir or the jet hood to> 400 mbar, preferably 150 to 250 mbar set. This pressure difference is sufficient to remove the blasting agent with the injection metering tube from the removal area of the blasting material bed and to meter accordingly sensitive in the transport stream.

Of particular advantage is further that the pressure difference between the jet dose and injection metering tube is maintained by an overpressure operated injector in the hose line, so that it is ensured that even with long hose leads the injection metering tube remains functional.

The inventive method is variable. Thus, it can be used anywhere where machining operations are carried out with the vacuum suction, for example, to remove paint defects from coatings, deburring, smoothing soldering and welding seams, removal of contaminated concrete layers or rust layers, hardening, leveling or coating metal surfaces, joining by welding, drilling and stripping solar cells, etc.

The object is further achieved by a device in that for dosing and conveying the bulk material immersed in the interior of the bulk bed in the reservoir, a removal area of the bed detecting injection metering tube is provided for sucking at least under atmospheric pressure or negative pressure air flow , In the downstream dosing tube is connected downstream with the injection jet through the hose inlet.

In a further embodiment of the device according to the invention, the reservoir on a cone bottom for Auflagerung the bulk material, which merges at its lowest point into a tubular, completed by a bottom removal area in which the bulk of the bed by gravity converges converges and the bed over the sampling area has an almost maximum bed height, whereby the injection

Metering tube is guided with its suction opening in the removal area for sucking and dosing of bulk material.

Another preferred feature of the device according to the invention provides that the injection metering tube has a suction opening which is in communication with the atmospheric air outside of the reservoir and whose size is adjustable by a slider.

In another embodiment of the The device according to the invention can be arranged in the injection tube but also completely within the reservoir. In this case, the suction port of the injection metering tube communicates with the negative pressure atmosphere in the reservoir.

The injection metering can with respect to the removal of any mounting position, preferably occupy an angle of 20 ° to the container axis, so that depending on the technical requirements, the injection dosing can be arranged horizontally, vertically or in an angular position.

In a further preferred embodiment of the device according to the invention is provided in the bottom of the removal area with the outside atmosphere in communication air inlet bore through which a certain amount of external air for loosening the Strahlmittelschüttung is directed into the removal area.

In a further preferred embodiment of the device according to the invention, a fluidizing pipe for supplying an atmospheric air flow for the purpose of loosening the bulk material in the bulk solids discharge of the removal area is performed. This allows an exact dosage of even the smallest amounts and prevents blockages at the suction port of the injection metering tube.

According to a further advantageous embodiment of the device according to the invention is in the removal area connected to the inflow cone of the separation unit Pitot tube for supplying an air flow from the negative pressure of the Separator provided for the purpose of loosening the bulk bed.

The device of the invention is simple and robust in construction and has the great advantage that the removal and metering of the bulk material quantity can be done directly from the negative pressure region of the reservoir without a special pneumatic separation of metering and feeding of bulk material are required.

Further advantages and details will become apparent from the following description with reference to the accompanying drawings.

Exemplary embodiment The invention will be explained in more detail below using an exemplary embodiment.

FIG. 1 shows a functional diagram of the method according to the invention with an injection tube in connection with the outside atmosphere, FIG.

Fig. 2 is a side view of the injection metering tube in a sectional view and

3 shows a variant of the method according to the invention, in which the injection metering tube communicates with the negative pressure atmosphere in the reservoir, Fig. 4a to 4c variants for loosening the abrasive bulk in the removal area.

Fig. 1 shows a schematic functional diagram of the method according to the invention for performing a processing on a vertical flat surface 1. With a suction unit 2, a carrier air flow T _LM of 20 m ³ / h to 300 m ³ / h and at the same time a negative pressure generated from 30 to 350 mbar. The suction unit 2 is connected via a hose 3 to a separation unit 4, which closes a reservoir 5 of about 0.1 to 200 liters pressure-tight, so that in the reservoir 5 of the suction unit 2 generated negative pressure of for example 200 mbar is applied.

The bottom 6 of the reservoir 5 is formed as a cone bottom 6a with an opening angle between 90 and 120 °, preferably 90 °, and has at its lowest point P in alignment with the container axis E-E closed by a bottom 8 removal area. 7

The reservoir 5 was filled before closing by the separation unit 4 with a loose bulk S of bulk material, such as corundum, glass breakage, zircon sand, slag, steel, cast steel, ceramics, welding powder, etc., which is stored on the conical bottom 6a. A portion of the bulk material slides by gravity along the conical bottom 6a and fills the closed by the bottom 8 to the outside removal area 7 with the bulk material, the bed height SH above the removal area 7 substantially reaches a maximum value.

In the removal area 7, an elongated injection metering tube 9 is guided, the suction port 10 close at the bottom 8 of the removal area 7 ends. The injection metering tube 9 penetrates the container wall 11 of the storage container 5 and is at an angle ß of> 5 ° (see also 4a) fixed to the container axis EE at this, wherein the penetration is pressure-tight. Downstream, the injection metering 9 has an intake 12, which is according to FIG. 1 outside of the reservoir 5 and thus has a direct connection to the atmospheric air. For further construction of the injection metering tube 9, reference is made to that in section [0034] (see also FIG. 2).

To the downstream opening 13 of the injection metering tube 9, a hose feed line 30 is connected to a

Injector jet lance 14 leads, the outlet end 15 in a

Beam hood 16 is introduced. The suction port 17 of

Injector jet lance 14 has connection to the outside atmosphere.

The further structure and operation of the injector jet lance 14 is described in detail in the prior art according to DE 101 02 924 Cl, so that further explanations can be omitted.

From the jet hood 16, a hose outlet 18 leads back to the reservoir 5, wherein the hose discharge 18 opens approximately in height of the Anströmkegels 19 of the separation unit 4 in the reservoir 5, so that a closed circuit for the carrier air Ström T _LM is formed, which ensures that in the injection metering tube 9, in the hose feed line 13, in the injector jet lance 14, in the jet hood 16 and the hose section 18 equally prevails in the reservoir 5 prevailing negative pressure p _UB , which may be in the range between 30 to> 350 mbar.

The carrier air flow T _LM promotes via the suction port 12 of the injection metering tube 9, an air flow L _D , the additional negative pressure p _D in the injection metering tube 9, ie at the suction opening 10 of the In dosing metering tube 9, and which sucks the bulk material from the removal region 7. The injection metering tube 9 is designed so that it can be operated at a negative pressure p _D of 60 to 360 mbar, ie there must always be a negative pressure difference Δρ between the negative pressure p _ST at the jet lance 14 and the negative pressure p _D at the injection metering 9 of at least 10 mbar in favor of the negative pressure at the injection metering tube 9 be present so that the injection metering 9 sure suck the desired amount of bulk material from the removal area 7 and can promote in the carrier air flow T _LM .

The bed height SH of the bulk bed reaches above the removal area 7 substantially a maximum, so that the bulk material in the reservoir 5 forms a sufficient barrier against the negative pressure p _VB in the rest of the reservoir 5. In other words, the removal region 7 is sealed off by the bulk material, so that the pressure applied to the injection metering 9, compared to the negative pressure P _U B in the reservoir 5 higher negative pressure p _D sufficient to remove the blasting agent from the removal area safely.

Depending on the type and shape of the bulk material can be adjusted by adjusting the amount of air flow L _D at the injection metering 9 depending on the pressure prevailing at the injection jet lance 14 negative pressure ₀ sT the amount of sucked bulk material.

Fig. 2 shows the basic structure of

Injection metering 9 in section in side view. The injection metering 9 consists of an outer tube 20 with a diameter of for example 20 mm, in which an inner tube 21 is inserted with, for example, a diameter of 10 mm and due to the small

Diameter difference forms an annular gap to S ugöffnung 10 out.

The inner tube 21 is shorter in relation to the outer tube 20 and ends in front of the suction opening 10 arranged in the outer tube 20. Both tubes 20 and 21 are fixed in a sleeve 22. At the downstream end 13 of the outer tube 20 is the suction port 12 for sucking the air flow L _{D /} whose size can be adjusted by a slider 23 according to the desired metered amount of bulk material to be sucked. The suction-side end 24 of the outer tube 20 is closed by a cover 25 bent at an angle of, for example, 35 °.

The suction opening 10 of the In ektions-Dosierrohres 9 is parallel to the longitudinal axis B-B of the outer tube in the lateral surface of the outer tube 20, so that a blockage of the suction opening 10 is counteracted by bulk material.

Depending on the nature of the bulk material, the outer tube 20 and inner tube 21 of the Inj dosing metering tube 9 made of stainless steel, ceramic or other wear-resistant materials.

FIG. 3 illustrates a further variant of the method according to the invention. The injection metering tube 9 is in this case completely in the reservoir 5 and has no connection to the outside atmosphere. The suction port 12 of the injection metering 9 sucks the air flow L _D from the

Low pressure atmosphere of the reservoir 5 at.

The course and mode of operation of the method according to the invention then further correspond to that described in section [0034] shown way. It only has to be ensured that the pressure difference .DELTA..beta. In the negative pressure between the injection pipe 9 and the injection jet lance 14 reaches a corresponding magnitude. This can be assisted, for example, with an injector 29 which is additionally inserted into the hose feed line 30 and which is operated with overpressure.

4a to 4c show ways to loosen the filled with bulk removal area 7 in the reservoir 5.

This can -as shown in FIG. 4a-most simply take place in that an air inlet bore 26 is provided in the bottom 8 of the removal region 7, which makes it possible to direct an air flow L _F into the removal region 7, as a result of which the charge of the bulk material in the removal area 7 is locally loosened.

Fig. 4b shows another variant of the loosening, which consists in that a fluidizing tube 27 is guided into the removal region 7. Finally, Fig. 4c shows the possibility of the inflow cone 19 of the separation unit 4 via a pitot tube 28 an air flow L _R from the carrier air flow TLM targeted as a dynamic pressure in the removal area 7 to lead.

All variants equally ensure adequate loosening of the bulk material bed in the removal area 7, so that the appropriate amount of bulk material can be reliably removed with the injection metering tube 9.

It is understood that the injection metering 9 inside and outside of the reservoir 5 can have any mounting position with respect to the removal area 7. Thus, the injection metering tube 9 can be arranged horizontally, vertically or even at an angle β of, for example, 10 ° to the container axis EE.

[0039] List of Reference Numerals

Vertical working surface 1

Suction unit 2

Hose line 3

Separating unit 4

Reservoir 5

Bottom of 5 6

Cone bottom 6a

Removal area 7

Bottom of 7 8

Inj ektions-Dosierrohr 9

Suction opening of 9 10

Container wall of 5 11

Suction opening of 9 for air flow L _D 12

Outgoing end of 9 13

Inj ector beam lance 14

Exit end of 14 15

Jet hood 16

Intake opening of 16 17

Hose outlet 18

Flow cone of 4 19

Outer tube of 9 20

Inner tube of 9 21

Sleeve of 9 22

Slide of 9 23

Suction-side end of 9 24 Lid of 20 25 air intake hole in 8 26

Fluidizing tube 27

Pitot tube 28

Additional injector in 30 29

Hose feed 30 Tank axis E-E Suctioned from the injection metering tube 9

Air flow L _D Air flow L _ST sucked in by the jet lance 14

Air flow sucked in from the Pitot tube 28 L _A Air flow of the air Access hole L _F

Bulk filling S

Schütthöhe SH

Carrier air flow T _LM

Negative pressure in 5 PUB negative pressure on the injection metering tube 9 PD

Negative pressure on jet lance 14 p _ST

Vacuum difference between 9 and 14 Δρ

Lowest point of the sampling area 7 P

Opening angle of 6a et angular position of 9 ß

- For this 6 sheets drawing

Claims

claims

1. Method for conveying and metering bulk material, for example blasting agents, - welding powder,

Coating agent o. The like., During processing, bonding or coating surfaces by vacuum suction, in which the bulk material in one of a suction unit (2) under negative pressure (P _U B) set reservoir (5) held by this the bulk material on a

Hose line (3) to .Einj ektions-beam lance (14) transported there accelerated by an atmospheric sucked foreign air flow and held on a through a jet hood under negative pressure (P _U B)

Working surface (1) directed, sucked from the jet hood (14}, then a separation unit (4) for cleaning and fed back into the reservoir (5), so that the bulk material can be circulated, characterized in that with a in a A suction flow for removal and dosing of the bulk material is generated, the negative pressure (p _D ) set by sucking a standing at least atmospheric pressure or negative pressure air flow (L _D ) as transport air to a value is greater than the negative pressure ( _UB ) in the jet hood (14) or in the reservoir (5), wherein the removal or metering of the bulk material by means of between the jet lance (14) and injection metering (9) prevailing negative pressure difference ( Δρ) of the sucked air streams (L _D ; L _ST ) of injection metering tube (9) and jet lance (14) is adjusted.

2. The method according to claim 1, characterized in that the bulk material is stored on a conical bottom (6a) in the reservoir {5) b, in whose tube-like, bottom-side closed removal area (7), the bulk material brought together by gravity and the dumping height (SH) on the removal region (7) assumes almost a maximum value, wherein the suction flow generated by the injection metering tube (9) for removal and metering of the bulk material is directed into this area.

3. The method according to claim 1, characterized in that the bulk of the bulk material in the removal region (7) by an atmospheric external air flow (L _F ) is loosened from the outside with a fluidizing tube (27) or by a removal region (7) associated with air inlet bore (7). 26) is directed into the removal area (7),

4. The method according to claim 1, dadurchgekennzeichne that the bulk of the bulk material in the removal region (7) by a from the suction of the separation unit (4) removed air stream (L _Ä ) is loosened, with a via a in Anströmkegel {19} of the separation unit (4) connected pitot tube (28) in the removal area (7) is directed.

5. The method according to claim 1, characterized in that the negative pressure (P _U ST) arn

Injection metering tube (9) to values between 60 to> 360 mbar, preferably 200 mbar and the negative pressure in the reservoir (5) or the jet hood (14) is set to 50 to 350 mbar.

6. The method according to claim 1, characterized in that the pressure difference (Δρ) between injector jet lance (14) and injection metering tube (9) with positive pressure in the hose line (13) operated additional injector (29) is maintained.

7. Apparatus for carrying out the method according to

Claim 1, with at least one storage container (5) for receiving a loose bulk material, a separation unit (4) for cleaning the bulk material, a suction unit (2) connected to the separation unit (4) for generating a negative pressure (PUB) in the storage container (5). , a hose feed line (13) connected to the storage container (5) for transporting the bulk material into an injection jet lance (14) for accelerating the bulk material through an injection jet lance (14) guided to a jet hood (16) under reduced pressure (PUB). 16) sucked atmospheric air flow (L _ST ) in the direction of a processing surface (1) and a hose hood (16) connected to the hose discharge (18) for sucking the bulk material and the removed particles from the jet hood (16} in the separation unit (4), characterized in that for dosing and conveying the bulk material, a dipping into that of the bulk material in the reservoir (5}, a withdrawal region (7) of the filling detecting injection metering tube (9) is provided for sucking a at least atmospheric pressure or negative pressure air stream, said injection metering tube (9) downstream with the injection jet lance (14) through the hose feed line (13) connected is.

8 = An apparatus according to claim 7, characterized in that the storage container (5) has a conical bottom (6a) for depositing the bulk bed, which merges in its lowest point (P) in a tubular, through a bottom (8) closed removal area (7) , in which the bulk material of the bulk bed merges by gravity focusing and the bulk bed above the removal area (7) has a nearly maximum bed height (SH), wherein the Inj ektions Dosierrohr (9) with its suction opening (10) in the removal area (7) for sucking and dosing of the bulk material is performed.

9. The device according to claim 7, characterized in that the injection dosing tube (9) has an intake opening (12) which communicates with the atmospheric air outside the storage container (5) and whose size is adjustable by a slide (23).

10. The device according to claim 7, characterized in that the injection metering tube

(9) has a suction port (12) which is in communication with the negative pressure atmosphere of the reservoir (5).

11. The device according to claim 7, characterized in that the in dosing dosing tube (5) an arbitrary mounting position with respect to the removal area (7), preferably an angle (ß) of 10 ° to

Container axis (EE), comprising.

12. The device according to claim 7, characterized in that in the bottom (8) of the removal region (7) an air inlet bore (26) communicating with the outside atmosphere is arranged for loosening the bulk material bed of the removal region (7).

13. The device according to claim 7, dadurchgekennzeichne that a fluidizing tube (27) for supplying an atmospheric air flow (L _F ) for the purpose of loosening the bulk material in the

Bulk filling of the removal area (7) is guided.

14. The device according to claim 7, characterized in that in the removal region (7) to the Anströmkegel (19) of the separation unit (4) connected pitot tube (28) for supplying an air flow (L _A ) from the negative pressure atmosphere in the reservoir (5) in order Loosening of the bulk bed in the removal area (7) is guided.

15. Device according to claim 7, characterized in that in the hose feed line

(13) an overpressure operated additional injector (29) for maintaining the pressure difference (Δρ) is provided.