EP3523091B1 - Method and device for ascertaining the operating state of a blasting system - Google Patents

Description

The invention relates to a method and a device for determining an operating state of a blasting system for treating a surface of a workpiece with a blasting agent. Such a method according to the preamble of claim 1 and such an apparatus according to the preamble of claim 10 are from document DE 3131002 A1 famous.

the DE 20 2016 100 542 U1 discloses a system for the timely provision of treatment agent, in particular granular blasting agent. In the known system, a bunker for receiving blasting agent is provided with a weight measuring device. As soon as a measured value recorded by the weight measuring device falls below a predetermined threshold value, the treatment agent is manually replenished in the bunker. In this way, an undesired forced interruption of jet operation due to an insufficient quantity of treatment agent can be avoided.

the DE 31 31 002 A1 describes an automatic pressure blasting system with precise and reproducible dosing of the blasting agent. The pressure blasting system includes two main bunkers, each with a minimum and a maximum fill level switch, which, when a minimum fill level is detected, causes automatic refilling from a refill bunker until the maximum fill level is reached.

the DE 10 2015 000 632 A1 discloses a method for operating a particle beam system and a particle beam system. The throughput of the blasting agent is measured during operation using an inductive measuring device. From the WO 2014/040125 A1 an inductive level measurement in blasting systems is known.

the EP 0 456 502 A1 discloses a device for detecting a radiance or intensity in a blasting process. The measurement is based on the detection of sound waves.

the DE 103 32 713 B3 relates to a beam intensity measuring device for surface treatment facilities. The beam intensity measuring device comprises an impulse sensor for measuring the impulse generated by the beam of blasting agent.

Depending on the surface to be treated, blasting media with a specific predetermined grain size distribution are used in state-of-the-art blasting systems. The blasting agent is thrown against a surface of the workpiece to be treated by means of a blasting agent acceleration device, for example a turbine wheel or the like. The blasting abrasive is then returned to the main bunker and is thus ready for further surface treatment. The proportion of fines in the grain size distribution of the blasting agent increases over time. In order to keep the grain size distribution within a predetermined range, the fines are removed from the blasting medium by means of air classification. To compensate for the amount of fines removed, new blasting media is added to the blasting media. The new blasting agent is usually fed from a pre-bunker to the main bunker when the fill level in a main bunker falls below a minimum level. The pre-bunker is then usually refilled manually.

In the case of blasting systems according to the prior art, the consumption of blasting agent is usually determined or estimated empirically, depending on the surface to be treated. The efficiency of a blasting system is not determined according to the state of the art.

The object of the invention is to eliminate the disadvantages of the prior art. In particular, a method and a device are to be specified which make it simple and easy to determine an operating state of a blasting system enable quickly. A possibility should also be provided with which the efficiency of the blasting system can be determined.

This object is solved by the features of patent claims 1 and 10. Expedient configurations of the invention result from the features of patent claims 2 to 9 and 11 to 15.

• fortlaufende Messung eines Füllstands an Strahlmittel in einem stromaufwärts einer Strahleinrichtung vorgesehenen Hauptbunker,
• Nachdosieren von Strahlmittel von einem stromaufwärts des Hauptbunkers vorgesehenen Vorbunker in den Hauptbunker, so dass der Füllstand im Hauptbunker innerhalb eines vorgegebenen Füllstandbereichs gehalten wird,
• Messen der vom Vorbunker an den Hauptbunker nachdosierten Gewichte und Erfassen der gemessenen Gewichte über der Zeit,
• Messen einer Stromaufnahme einer Strahlmittelbeschleunigungseinrichtung und Messen einer tatsächlichen Strahldauer,
• Bestimmen eines Strahldauerzeitintervalls,
• Ermitteln eines mittleren Strahlmittelverbrauchs für einen bestimmten Zeitpunkt aus dem während des vorgegebenen Strahldauerzeitintervalls bis zum bestimmten Zeitpunkt nachdosierten Gesamtgewicht an Strahlmittel,
• Wiederholen des Schritts der Ermittlung des mittleren Strahlmittelverbrauchs für nachfolgende weitere bestimmte Zeitpunkte, und
• Anzeigen des jeweiligen mittleren Strahlmittelverbrauchs über den jeweiligen bestimmten Zeitpunkten.

According to a first aspect of the invention, a method for determining an operating state of a blasting system for treating a surface of a workpiece with a blasting agent is proposed, having the following steps:

• continuous measurement of a filling level of blasting agent in a main bunker provided upstream of a blasting device,
• Replenishment of blasting media from a preliminary bunker provided upstream of the main bunker into the main bunker, so that the filling level in the main bunker is kept within a predetermined filling level range,
• Measuring the weights added from the preliminary bunker to the main bunker and recording the measured weights over time,
• Measuring a power consumption of a blasting agent acceleration device and measuring an actual blasting duration,
• determining a beam duration time interval,
• Determination of an average blasting agent consumption for a specific point in time from the total weight of blasting agent metered during the specified blasting duration time interval up to the specific point in time,
• repeating the step of determining the mean consumption of blasting agent for subsequent further specific points in time, and
• Display of the respective mean consumption of abrasive over the respective specific points in time.

For the purposes of the present invention, the term "blasting agent" is understood to mean a material consisting of grains which has a predetermined grain size distribution in the delivery or initial state. The grains can be formed from different materials, for example metal, ceramic, glass or the like. - A "blasting agent acceleration device" is understood to mean a device with which the blasting agent is accelerated, in particular in the direction of the surface to be treated. This can be, for example, a turbine wheel, an accelerated gas flow or the like.

By "measuring the power consumption of the blasting agent acceleration device" it is possible to determine an "actual blasting duration". The term "actual blasting duration" is understood to mean a period of time during which the blasting agent hits the surface to be treated with a predetermined minimum impulse. The minimum impulse can be recorded indirectly through the power consumption of the blasting agent acceleration device. i.e. the blasting duration corresponds to the duration during which the blasting agent acceleration device works properly and is properly exposed to blasting agent. On the other hand, idling operation must be distinguished, for example, during which the blasting agent acceleration device is driven but not supplied with blasting agent. - The power consumption of the blasting agent acceleration device can also be recorded indirectly by measuring a total power consumption of the blasting system. On the basis of a measurement of the total power consumption, the overall efficiency of the blasting system can also be determined.

The term "beam duration time interval" means a time interval from the measured actual beam duration. The beam duration time interval can freely to be determined. A duration of 24 hours is usually selected as the beam duration time interval.

A "specific point in time" is understood to mean a predetermined selected point in time. It can be, for example, the full hour in each case.

In order to determine an "average consumption of blasting agent", starting from a specific point in time, a mean value is formed retrospectively from the total weight of blasting agent metered during the predetermined blasting duration time interval up to the specific point in time.

The predetermined blast duration time interval is preferably in the range between 6 and 48 hours, in particular 12 to 36 hours, particularly preferably 24 hours. i.e. For example, a total weight of subsequent blasting agent is determined for a specific point in time "8 o'clock" during a blasting time interval of 24 hours that has elapsed up to that point.

The step "determining the mean consumption of blasting agent" is then repeated for the subsequent further specific points in time. i.e. the mean consumption of blasting agent is determined, for example, for the specific points in time "8 o'clock", "9 o'clock", etc.

Finally, the respective mean consumption of blasting medium determined in this way is displayed over the respective specific points in time.

The mean consumption of abrasive is an objective measure of the efficiency of the blasting system. A blasting system can be optimized using the average consumption of blasting media. The optimization can be done, for example, by selecting a blasting agent with a different grain size distribution, a different geometry of a blasting agent acceleration device and/or a different specified performance for the operation of the blasting agent acceleration device can be achieved. Apart from that, the consumption of blasting agent can now be recorded exactly. This enables timely and sufficient storage of blasting media at all times.

A duration of n*12 hours is advantageously chosen as the beam duration time interval, where n is a natural number. i.e. durations of, for example, 12, 24, 36, . . . hours are selected as the beam duration time interval.

In order to calculate the average blasting agent consumption, the quotient is advantageously formed from the total weight of blasting agent metered in the predetermined blasting duration time interval and the duration of the predetermined blasting duration time interval.

Example: specified beam duration time interval: 24 hours Total weight of downstream abrasive in the blasting time interval: 24kg Average abrasive consumption: 24 kg / 24 h = 1 kg/h

According to an advantageous embodiment of the invention, in the case of metallic blasting media, the fill level in the main bunker is continuously measured by means of an inductive fill level measuring device. Such inductive measuring devices are generally known in the prior art.

Expediently, an outlet opening is automatically opened for a predetermined period of time for replenishment at the pre-bunker. For this purpose, a slide can be provided at the outlet opening, which can be opened and closed, for example, electrically or pneumatically. The proposed replenishment at intervals is robust and unaffected.

According to a further advantageous embodiment, a difference is formed between a first weight of the preliminary bunker together with the blasting medium contained therein before the subsequent dosing and a second weight of the preliminary bunker together with the remaining blasting medium after the subsequent dosing, in order to measure the weights of blasting agent that have been replenished in each case. The second weight is expediently measured immediately after the outlet opening has been closed. The second weight is compared to the previously measured first weight, which was determined before the outlet opening was opened. The difference between the first and the second weight results in a third weight of the blasting medium that is replenished at intervals. The proposed difference measurement between the first and the second weight is robust and insensitive. It can be done, for example, by pressure cells, on which the preliminary bunker is at least partially supported.

The third weights can be summed over the beam duration time interval. From the sum of the third weights, the replenished total weight of blasting agent during the blasting time interval can be determined.

According to a further, particularly advantageous embodiment, the third weights of replenished blasting agent are summed up over time, the respective sum is compared with a further quantity or weight in storage and when a predetermined minimum quantity or a minimum weight of blasting agent in storage is reached Remote data transmission causes a subsequent delivery of blasting media. This ensures that a sufficient supply of blasting agent is available at all times. An undesired standstill of the blasting system due to insufficient storage of blasting media is avoided.

Expediently, to determine the actual beam duration, those time sections are summed up in which the power consumption is greater than a predetermined limit value. The predetermined limit is advantageously chosen so that he to a predetermined optimal operating state Corresponds to blasting material acceleration device. Falling below the specified limit value indicates that, for example, the blasting agent acceleration device is worn out, not enough blasting agent has been replenished, or a grain size composition of the blasting agent has changed in an undesirable manner. By triggering a warning signal, you can react quickly and restore the desired operating status. A specified quality of the surface of the workpieces to be treated can thus be ensured. Waste is avoided.

According to a second aspect of the invention, a device according to claim 10 for determining an operating state of a blasting system for treating a surface of a workpiece with a blasting agent is proposed, comprising a data processing device prepared for carrying out the method according to the invention.

The device can also include a device for measuring a current consumption of the blasting agent acceleration device and/or the blasting system, which is or can be connected to the data processing device for signal transmission. In particular, the measurement of the power consumption of the blasting agent acceleration device and/or the blasting system enables an energetic evaluation of the efficiency of the blasting system. For example, it can be specified what total amount of current is required to treat a given surface, number of pieces or a given weight of workpieces. Furthermore, the abrasive consumption can be specified in relation to the weight or the surface of the treated workpieces.

Furthermore, the device can include a device for measuring the weight of the preliminary bunker, which is connected or can be connected to the data processing device for signal transmission. The device can also include a pre-bunker, which is provided with the device for measuring the weight.

Furthermore, the device can include a fill level measuring device for measuring the fill level of the main bunker. The filling level measuring device can be connected or can be connected to the data processing device for signal transmission.

Furthermore, the data processing device can be connected or can be connected via the Internet to at least one other data processing device for remote data transmission. The additional data processing device can be a mobile phone, a terminal at a blasting agent supplier or the like.

Fig. 1

eine schematische Darstellung einer Strahlanlage,

Fig. 2

das Gewicht an nachdosiertem Strahlmittel über der Zeit,

Fig. 3

die Stromaufnahme einer Strahlmittelbeschleunigungseinrichtung über der Zeit und

Fig. 4

die Strahlleistung über der Zeit.

An exemplary embodiment of the invention is explained in more detail below with reference to the drawings. Show it:

1

a schematic representation of a blasting system,

2

the weight of replenished blasting agent over time,

3

the power consumption of a blasting material acceleration device over time and

4

the beam power over time.

At the in 1 shown blasting system is generally denoted by the reference numeral 1, a blasting device, in which a blasting agent acceleration device 2, z. B. a turbine, for accelerating blasting agent 3 onto a surface of a workpiece 4 indicated schematically here.

• Das Bezugszeichen 8 bezeichnet eine von der Strahleinrichtung 1 zum Hauptbunker 5 verlaufende Rückführeinrichtung, durch welche das Strahlmittel 3 - nach einer (hier nicht näher gezeigten) Windsichtung - zum Hauptbunker 5 zurückgeführt wird. Die Rückführeinrichtung 8 umfasst eine Rückführleitung, in welcher beispielsweise ein Schneckenförderer (hier nicht gezeigt) und/oder ein Becherförderer (hier nicht gezeigt), aufgenommen sind.

The reference numeral 5 generally designates a main bunker, which is arranged upstream of the blasting device 1 with respect to a conveying direction of the blasting agent 3 . A filling level measuring device 6 is provided in the main bunker 5 . Reference number 7 designates a first slide, which can be selectively opened and closed in order to provide blasting agent 3 .

• The reference number 8 designates a return device running from the blasting device 1 to the main bunker 5, through which the blasting agent 3 is returned to the main bunker 5—after an air classification (not shown in detail here). The return device 8 comprises a return line, in which, for example, a screw conveyor (not shown here) and/or a bucket conveyor (not shown here) are accommodated.

Upstream of the main bunker 5 there is a pre-bunker, generally designated by the reference numeral 9, which is provided with a second slide 10. The second slide 10 can be selectively opened and closed, so that blasting agent 3 can be fed from the preliminary bunker 9 to the main bunker 5 at intervals, in particular via the return device 8 . The blasting agent 3 can be replenished at intervals automatically depending on the fill level in the main bunker 5 .

The preliminary bunker 9 is supported against a substrate U via pressure cells 11 . A data processing device is indicated schematically by reference number 12 . The data processing device 12 is connected via a first signal line 13 to the blasting agent acceleration device 2 , via a second signal line 14 to the filling level measuring device 6 and via a third signal line 15 to the pressure cells 11 .

The reference number 16 designates a switch with which an open or closed state of the cover 17 of the pre-bunker 9 is detected. The switch 16 is connected to the data processing device 12 via a fourth signal line 18 .

Reference number 19 designates a fifth signal line, via which signals or data can be transmitted from the controller 12 to the second slider 10 for closing and opening the same.

Signals or data are supplied via the first signal line 13 which correspond to the power consumption of the blasting agent acceleration device 2 . Signals or data are transmitted via the second signal line 14 which correspond to the fill level of the blasting medium 3 in the main bunker 5 . Signals or data which correspond to the weight of the preliminary bunker 9 are transmitted via the third signal line 15 . Signals or data are transmitted via the fourth signal line 18 which indicate whether the cover 17 is open or closed.

Furthermore, a further device (not shown here) for measuring the power consumption of the entire blasting device 1 can be provided. The total power consumption also includes, in particular, the power required to transport the blasting agent 3 by means of the return device. For this purpose, the return device 8 includes, for example, a bucket elevator.

The function of the device and the process that can be carried out with it is as follows:
With the blasting agent acceleration device 2, blasting agent 3 is thrown against the surface of a workpiece 4, as a result of which the surface is removed. As a result, a fine grain fraction forms in the blasting agent 3, which is unsuitable for blasting the surface of the workpiece 4. The fine grain fraction is removed from the blasting medium 3 by means of a conventional air classification. The appropriately prepared blasting medium 3 is returned from the blasting device 1 to the main bunker 5 by the return device 8 . In the main bunker 5 the fill level of blasting agent 3 is continuously measured by means of the fill level measuring device 6 . The corresponding measured values are supplied to the data processing device 12 via the second signal line 14 .

As soon as the fill level in the main bunker 5 falls below a predetermined minimum value, the second slide 10 on the pre-bunker 9 is opened for a predetermined period of time. As a result, new blasting medium 3 is fed to the main bunker 5 at intervals via the return device 8 . In doing so, before opening of the second slide 10, a first weight of the preliminary bunker 9 together with the blasting agent 3 contained therein is measured by means of the pressure cells 11. The first weight is stored in the data processing device 12 . After the second slider 10 has been closed, a second weight of the preliminary bunker 9 together with the blasting agent 3 still remaining therein is measured. A third weight results from the difference between the first weight and the second weight, which corresponds to the amount of blasting agent 3 that has been replenished.

The weight of replenished blasting agent 3 or the amount resulting therefrom is recorded over time by the data processing device 12 (see FIG 2 ). Furthermore, the power consumption of the blasting material acceleration device 2 over time is recorded with the data processing device 12 via the first signal line 13 (see FIG 3 ).

A limit value is expediently specified with regard to the power consumption. If the power consumption is above the limit value, the blasting agent acceleration device 2 is properly loaded with blasting agent 3 . The blasting agent acceleration device 2 is in “blasting mode” above the limit value. If the current consumption falls below the limit value, this indicates improper operation of the blasting agent acceleration device 2 or that it is idling. Improper operation can be caused, for example, by worn turbine blades, bearing damage or the like. An idle state can be caused, for example, by an interruption in conveying in the return device 8 .

If the power consumption falls below the limit value, an alarm signal is advantageously triggered by means of the data processing device 12 .

The power consumption of the blasting agent acceleration device 2 is recorded over time by the data processing device 12 . Advantageously, only those are used to determine the actual beam duration Sums up the time intervals at which the current consumption is above the limit value.

4 shows the mean abrasive consumption over time. In order to determine the average blasting agent consumption, a value is advantageously plotted on the y-axis for the respective specific points in time, which z. B. for the time 08:30 a.m. results as follows: $${\mathrm{y}}_{08:30\mathrm{Clock}}=\sum \left(\begin{array}{l}\mathrm{downstream}\mathrm{third}\mathrm{weights}\mathrm{in\; the}\mathrm{chosen}\mathrm{Beam-}\\ \mathrm{duration\; time\; interval}\end{array}\right)/\left(\begin{array}{l}\mathrm{number}\mathrm{the}\mathrm{hours}\mathrm{of}\mathrm{beam\; duration\; time\; interval}\\ \mathrm{Valls}\end{array}\right)$$

In 4 the average abrasive consumption for the specific time 08:30 a.m. is 20 kg/h. In the blasting time interval between 8:30 a.m. (previous day) and 8:30 a.m., 24 x 20 kg = 480 kg of blasting agent were used. - For the specific point in time at 09:30 a.m., the average blasting agent consumption is 30 kg/h, ie in the selected blasting time interval from 09:30 a.m. (previous day) to the specific point in time at 09:30 a.m., a total of 24 x 30 kg = 720 kg of blasting agent is used been.

From the increase in the average consumption of blasting media, it can be concluded that the effectiveness of the blasting system has decreased if the workpieces to be blasted have not been changed.

To optimize the method, for example, the grain size distribution of the blasting agent 3, a pulse transmitted from the blasting agent acceleration device 2 to the blasting agent 3, etc. can be varied. Furthermore, depending on the workpiece 4 to be machined, optimal beam powers determined beforehand can be set from the outset.

Due to the continuous recording of the weight of blasting agent 3 removed from the preliminary bunker 9 (see 2 ) it is possible by means of the data processing device 12 via the Internet automatically via a supplier Trigger additional delivery to blasting agent 3. In this way, undesired interruptions in delivery can advantageously be avoided.

The switch 16 is used to monitor whether the cover 17 is open or closed. When the cover 17 is open, the second slide 10 is automatically blocked, i.e. as long as the cover 17 is open, there is no replenishment of blasting agent 3 from the preliminary bunker 9 into the return device 8. This prevents the weight being measured when the preliminary bunker 9 is refilled replenished blasting agent 3 is falsified. When the switch 16 or the cover 17 is closed, on the other hand, automatic replenishment of blasting agent 3 is possible, as described above.

reference list

1

blasting device

2

Abrasive acceleration device

3

abrasive

4

workpiece

5

main bunker

6

level gauge

7

first slider

8th

return device

9

prebunker

10

second slider

11

load cell

12

data processing facility

13

first signal line

14

second signal line

15

third signal line

16

counter

17

lid

18

fourth signal line

19

fifth signal line

f

conveying direction

u

underground

Claims (15)

1. A method of detecting an operating condition of a blasting machine for treating a surface of a workpiece (4) with a blasting medium (3), comprising the steps of:

   continuously measuring a level of abrasive (3) in a main hopper (5) provided upstream of a blasting device (1), and

   replenishing blasting medium (3) from a pre-bunker (9) provided upstream of the main bunker (5) into the main bunker (5) so that the filling level in the main bunker (5) is kept within a predetermined filling level range,

   characterized in that the method comprises the following further steps:

   measurement of the weights replenished from the pre-bunker (9) to the main bunker (5) and recording of the measured weights over time,

   measuring a current consumption of a blasting medium accelerating device (2) and measuring an actual blasting time,

   determining a blasting duration time interval,

   determining an average abrasive consumption for a specific point in time from the total weight of abrasive (3) replenished during the specified blasting time interval up to the specific points in time,

   repeating the step of determining the average abrasive consumption for subsequent further specified points in time, and

   display of the respective average abrasive consumption over the respective specific points in time.
2. The method of claim 1, wherein the blasting duration time interval is selected to be n * 12 hours, where n is a natural number.
3. The method according to any one of the preceding claims, wherein, in order to calculate the average abrasive consumption, the quotient is calculated from the total weight of abrasive (3) subsequently replenished in the predetermined blasting duration time interval and the duration of the blasting duration time interval.
4. The method according to any one of the preceding claims, wherein the continuous measurement of the filling level in the main hopper (5) is carried out by means of an inductive filling level measuring device (6).
5. The method according to any one of the preceding claims, wherein an outlet opening (10) is automatically opened for a predetermined period of time at the pre-bunker (9) for subsequent replenishment.
6. The method according to any one of the preceding claims, wherein for measuring a respective replenished third weight of abrasive (3) a difference is calculated between a first weight of the pre-bunker (9) before replenishment and a second weight of the pre-bunker (9) after replenishment.
7. The method according to any one of the preceding claims, wherein the third weights of subsequently replenished blasting medium (3) are summed over time, the respective sum is compared with a further quantity in stock or a further weight and, when a predetermined minimum quantity or a predetermined minimum weight of blasting medium (3) in stock is reached, a subsequent delivery of blasting medium (3) is automatically initiated via remote data transmission.
8. The method according to any one of the preceding claims, wherein for determining the actual blasting duration, those time periods are summed for which the current consumption is greater than a pre-set limit value.
9. The method according to any one of the preceding claims, wherein a warning signal is generated when the value falls below the predetermined limit value.
10. A device for detecting an operating condition of a blasting machine for treating a surface of a workpiece (4) with a blasting medium (3), comprising a data processing device (12),

    characterized in that

    the data processing device (12) is adapted to perform a method according to any one of the preceding claims,

    wherein the data processing device cooperates with

    a level measuring device (6) for continuously measuring a level of blasting medium (3) in a main hopper (5) provided upstream of a blasting device (1),

    a device for replenishing blasting medium (3) from a pre-bunker (9) provided upstream of the main bunker (5) into the main bunker (5), so that the filling level in the main bunker (5) is kept within a predetermined filling level range,

    a device for measuring the weights subsequently replenished from the pre-bunker (9) to the main bunker (5),

    a device for measuring a current consumption of a blasting medium acceleration device (2) and for measuring an actual blasting time, and

    a device for displaying.
11. The device according to claim 10, comprising a device for measuring a current consumption of the abrasive blasting means (2) and/or of the blasting machine, which is connected or connectable to the data processing device (12) for signal transmission.
12. The device according to claim 10 or 11, comprising a device (11) for measuring the weight of the pre-bunker (9) which is connected or connectable to the data processing device (12) for signal transmission.
13. The device according to claim 12, comprising a pre-bunker (9) provided with the device (11) for measuring the weight.
14. The device according to any one of claims 10 to 13, comprising a filling level measuring device (6) for measuring the level of the main hopper (5), which is connected or connectable to the data processing device (12) for signal transmission.
15. The device according to any one of claims 10 to 14, wherein the data processing device (12) is connected or connectable via the Internet to at least one further data processing device for remote data transmission.

Images