HRP980140A2 - Device for conveying pulverulent or granular material - Google Patents

Abstract

Conveying device for transporting powdered or granular material such as mortar from a storage container (1) through a hose (3) to a consumer (2) comprises a compressor (4) producing compressed air for transporting the material, a shut-off valve (10) between the storage container and the hose, and a time switch element. When the shut-off valve is closed the time switch element controls further transport of the transporting air over a specified period. The storage container is connected to the hose via a line (5) and opens into the front of the shut-off valve. A valve is arranged in the line. An Independent claim is also included for a process for transporting powdered or granular material from a storage container through a hose to a consumer using compressed air. Preferred Features: A pressure-monitoring device (18), e.g. a pressure switch, in the hose closes the shut-off valve when a specified maximum pressure is exceeded.

Description

The invention relates to a transport device that transports powdered or granular material, such as plaster, from the container to the consumer through a transport hose, with a compressor for producing compressed air for transporting the material, and with a stop valve between the container and the transport hose.

The invention further relates to a method for transporting powdery or granular material using transport air in a hose for transport from a container to a consumer.

Such a device for transporting materials, such as plaster based on gypsum, lime or cement, is known. The material is then transported by means of a transport device to a silo towards a machine for further processing, for example towards a machine for ready mortar, which is also called a mixing pump, into which a certain amount of water can be continuously dosed to the continuously supplied dry mortar. By passing through the mixing zone, these components turn into a homogeneous wet mortar. After that, the plaster is pumped using the transport pump through the plaster hose towards the place of application. Using a spray device, wet plaster is accelerated using compressed air and applied to the surface to be plastered.

When transporting material from the silo to the mixing pump, relatively long hoses are often used, which on the one hand can lead to clogging during operation, and on the other hand, when the transport of the material is interrupted, to the settling of the material in the transport hose, which when restarted it can no longer release itself at the start of the transport, which can also lead to clogging. The transport hose must then be disassembled and cleaned manually, which can take several hours.

The task of the invention is to present a device for transport and a process in which the risk of clogging in the transport hose is reduced.

This task will be solved with the transport device according to the invention in such a way, that a connecting article with a clock mechanism is overlooked, which after closing the shut-off valve, controls the further transport of air for transport in a certain time interval.

In the process according to the invention, this task will be solved in such a way that after the interruption of the supply of material from the container to the transport hose, the air flow in the transport hose is still maintained for a certain time interval.

According to the invention, after the supply of material from the tank or silo to the transport hose is stopped, the supply of air for transport is maintained in the hose for a predetermined time interval, which will later be referred to as "post-blowing", which means that the transport hose the remaining material is removed and transported, for example, to a plastering machine.

This can occur when the transport of material is interrupted, for example after the work is finished, or when the dry material hopper of the plastering machine is full.

In the further construction of the transport device according to the invention, it can also be foreseen that a pressure monitoring device, e.g. a pressure switch, is provided in the transport hose in the transport hose, and that this monitoring device is pressure connected to the shut-off valve, whereby the shut-off valve is closed, when the set maximum pressure is exceeded. According to the invention, the air pressure for transport can be monitored and when the predetermined limit value is exceeded, the flow of material from the tank to the transport hose is interrupted.

If the predetermined maximum pressure is exceeded with the invention, this is simultaneously a sign that a blockage is forming or has already occurred in the transport hose. Monitoring the pressure actually prevents the blockage from progressing so far that it can only be removed manually. Then, in a certain time interval, they are additionally blown through, in order to remove the blockage, which succeeds in the majority of cases, and the transport hose is freed, after which the transport of the material can be continued.

Furthermore, in the transport device according to the invention, a further predictable device for monitoring the pressure in the transport hose can be provided, primarily a second pressure switch, which monitors the last lower pressure. According to the invention, it can be foreseen that after the beginning of transporting the air for transport, a certain time interval passes, for this, if during that time interval the certain pressure is not exceeded, the inflow of material from the container into the hose for transport begins.

According to the invention, with this extraordinary form, at the beginning of the transport, it is first examined whether the transport hose is blocked, since it is monitored at a certain time interval, whether a certain pressure has been exceeded. Exceeding a certain pressure would be a sign of clogging. Only after this time interval, if a certain pressure has not been exceeded, the shut-off valve between the tank and the transport hose is opened and the transport of the material towards the plastering machine begins.

According to the invention, the transport device can be upgraded so that the compressor is connected via a valve, primarily a return valve, to a pressure tank, which is connected to a stop valve, and further, that the compressor is connected to the tank via a pipe.

Thus, a single compressor can be used not only for controlling the shut-off valve via the pressure tank, but also for the production or maintenance of the required pressure in the tank, as well as for the production of transport air, which has not only a technical advantage but also an advantage in terms of cost.

Further features and advantages of the invention derive from the other sub-claims and the following description of the embodiment of the invention with reference to the drawing.

For the transport of powdery or granular material, such as plaster based on gypsum, lime or cement as dry plaster, from the tank 1 to the consumer 2, for example, a plastering machine or mixer-pump for plaster, through the transport hose 3, a compressor 4 is provided, which produces the necessary the pressure necessary to transport air for transport. The material is blown through the transport hose 3 from the tank 1 to the consumer 2 with the help of transport air.

Compressor 4 is connected via pipe 5 to tank 1 and via pipe 6 and pressure booster or pressure converter 7 to pressure tank 8. Pressure tank 8 is connected to valve 10 via pipe 9, which opens or closes the connection between tank 1 and transport hose 3. The valve 10 can be made as a clamping valve (pneumatic valve with a flange with a rubber cuff and is located in the distribution block 11, which forms a connection between the transport hose 3 and the tank 1.

Instead of the pressure transducer 7 which is connected to the compressor 4, another further compressor can be provided in this case in connection with the auxiliary source of electricity.

A control valve 12 is located in the pipe 5 between the tank 1 and the compressor 4. A control valve 13 is located in the transport hose 3 between the distribution block 11 and the compressor 4. A return valve 14 is located in the pipe between the compressor 4 and the pressure tank 8. In the connecting pipe 15 between pipes 5 and 6, the connections of which lie between the valve 12 and the tank 1, i.e. the return valve 14 and the pressure tank 8, a return valve 16 is arranged with leakage in the direction from pipe 5 to pipe 6.

In the pipe 5 between the compressor 4 and the tank 1, two pressure measuring devices 17 and 18 are provided, for example a pressure switch, the task of which will be explained later.

If the conveying device is put into operation, a blowdown is first carried out, if the pressure in the pipe 5 lies between a certain upper pressure and a certain lower pressure, as will be explained later.

After that, using the pressure measuring device 19, the pressure in the pressure tank 8 is tested, the minimum value of which lies, for example, between 2 and 3 bar, preferably 2.5 bar. If the pressure is lower, then the valves 12 and 13 first remain closed and the compressor 4 produces the required minimum pressure of 2.5 bar in the pressure tank 8 via the pressure converter 7.

When this pressure is reached, valve 12 is opened and two pressures are tested using pressure measuring devices 17 and 18, with pressure measuring device 17 testing the lower pressure and setting it between 1.0 and 1.4, primarily at 1.2 bar. and the pressure device 13 tests the upper pressure and adjusts it between 1.7 and 1.9 bar, primarily at 1.8 bar. If the actual pressure lies between these two pressures, the device remains at rest until either the pressure in the pressure tank 8 drops below 2.5 bar or the material level measuring probe 20, which measures the material level in the filling hopper 21 of the consumer 2, sends a claim signal material to the control mechanism of the transport device.

If the pressure in the pipe 5 is below 1.2 bar, then the pressure in the tank 1 is increased to that lowest pressure using the compressor 4. If this pressure cannot be reached after a certain time, e.g. 20 min, the device is disconnected after this time due to interference.

If the control mechanism of the transport device receives from the material probe 20 a signal for requesting material, it can be temporarily bridged over in the control mechanism of the existing potentiometer and/or in the housing of the material probe of the existing potentiometer, which can be adjusted continuously. At the end of this tensioning time, the so-called pre-blowing begins. In this pre-blowing, the compressor 4 is switched on, at the same time the valve 13 is opened and the transport air is blown through the transport hose 3. If the pressure during the pre-blowing, e.g. for 3 seconds, remains below the set lower pressure of 1.2 bar on the device for measurement 17, it can be assumed that the transport pipe 3 is not blocked and that the clamping valve 10 on the distribution block 11 is open, which pushes the material from the tank 1 into the transport pipe 3. The material is blown through the transport pipe for a long time 3 into the blowing funnel 21 of the consumer (eg pump-mixer for mortar) until the material probe 20 reaches the maximum level in the filling funnel 21 and informs the control mechanism of the transport device. Then the valve 10 is closed, so that no material can come from the tank 1 to the transport hose 3.

The compressor 4 blows after that within a certain time, so that the material, which is still in the transport hose 3, is blown out. The duration of the subsequent blowing can be adjusted using the hour switch, which is located in the control mechanism. After the set time has expired, valve 13 is closed and compressor 4 is disconnected.

If during transport the pressure rises above 1.8 bar, which is registered by the pressure measuring device 18, this indicates a blockage in the transport hose 3. Then the valve 10 closes and the compressor 4 will try to blow the residual material into the filling funnel 21 of the machine for plastering 2, which in most cases succeeds, because the blockage has not yet progressed so far that the transport hose could not be cleaned by blowing.

If the pressure in the transport hose 3 within a certain time interval, e.g. 30 sec, drops again to a value below 1.8 bar, then the valve 10 is opened again and the material can be sent to the consumer 2 again. If the pressure does not drop within a certain time interval to a value below 1.8 bar, then the transport hose 3 is purged for the entire time provided for subsequent purging. After that, the valve 13 is closed, the compressor 4 is turned off and the malfunction report indicates a blockage in the transport hose 3.

If during the transport phase, with subsequent deflation, the pressure in the transport hose 3 rises above 1.8 bar, then it can be taken, either simultaneously or after the end of the blow-down phase, to reduce the pressure in the tank 1, so that the air in the tank 1 is released through the hose for transport by opening valves 12 and 13. By reducing the pressure in tank 1, the transport of material from tank 1 to the transport hose 3 is reduced, so that the risk of clogging during the transport phase is reduced.

If during the transport phase the pressure in the transport hose 3 decreases, e.g. within 20 seconds, below 1.2 bar, then after the end of the transport and subsequent blowing, the pressure in tank 1 is automatically increased. 4 and simultaneously opening the valve 12 with compressed air pumps to 1.2 bar. This procedure continues either until a pressure of 1.2 bar is reached or until a time interval of 3 minutes has passed.

If during transport the existing pressure is less than 1.8 bar, and the "funnel full" signal does not come from the material probe 20, then the device transports the material through the transport hose 3 for a maximum of e.g. 30 min. If this time interval is exceeded, then the transport device stops by itself and reports the error "lack of material".

In case of power failure or intentional or unintentional disconnection of the transport device in operation, valves 12 and 13 open simultaneously. If valve 10 is fully open at the time of power failure or disconnection, it automatically closes, so that material from tank 1 can no longer enter the transport hose 3.

By opening the valves 12 and 13, the pressure in the tank 1 is used to deflate the transport hose 3, so that the device can be put into operation after re-connection without clogging the transport hose 3. When a certain time interval has passed, which can be set on the executive device 22, the valve 12 and 13 are closed again, so that not all the air from the silo is used to blow the transport hose.

The duration of subsequent blowing after stopping the flow of material from the tank 1 to the transport hose 3, regardless of the cause, can be adjusted to any hose length. in this way, silo 1 can also be completely emptied.

If, during subsequent blowing, a request for material is transmitted to the control mechanism of the transport device, then the valve 10 is opened, so that the transport of the material towards the plastering machine 2 could be carried out smoothly.

In general, at start-up, increasing the control pressure in the pressure tank 8 has absolute priority over all other functions of the transport device. During operation, only subsequent blowing and transport is more important than increasing the control pressure. If it is necessary to increase the control pressure, care must be taken that the transport phase should not last longer than a predetermined time interval, for example 30 sec. This is necessary and appropriate, because in this way, enough compressed air is present to close the pinch valve 10.

The pressure increase in the tank 1 is basically of secondary importance to the functioning of the control pressure increase in the pressure tank 8, as well as the transport and subsequent blowing.

Subsequent blowing again has a secondary importance compared to material transport, but has priority over increasing the control pressure. This means that subsequent blowing in each case ends and then the control pressure increase in the pressure tank 8 is carried out. Since, through valve 14 or 16, pressure from tank 1 is always available to increase the pressure in pressure tank 8, for closing of the clamping valve, there is always sufficient pressure.

The same applies to the transport itself, even related to the increase in steering pressure.

Reducing the pressure in the tank is of secondary importance compared to increasing the pressure for management, as well as transport and subsequent filling, which can also be carried out when reducing the pressure in the tank 1.

If, after connecting the transport device, the pressure in the pipe 5 with the open valve 12 is 1.2 bar, then with the help of compressed air from the tank 1 with the open valve 13, the transport hose 3 is completely deflated, e.g. for 40 seconds, and this process can be interrupted.

If the control pressure in the pressure tank 8 rises after the transport device has been put into operation, and the lowest value of 2.5 bar is not reached within a certain time, then the device is disconnected due to malfunctions.

Valve 12 remains always open during the preparatory phase, i.e. when the device is switched on, and when all pressures correspond to preset values. With this open valve, the control pressure in the pressure tank 8 is maintained by the pressure transducer 7, using the compressed air of the tank 1, always at an optimal value above 2.5 bar.

If the transport device does not receive any signal within e.g. 15 min, the pressure in tank 1 is tested by switching on the compressor for a minimum time of e.g. 5 seconds, and if necessary, the pressure in tank 1 is increased.

As already mentioned, increasing the pressure during the working phase of the device has no absolute advantage. If the control receives a signal that an increase in the control pressure is necessary, the transport will continue again within a certain time interval. If the transport is not completed by then, subsequent blowing is carried out using the automatically increased control pressure. If an increase in control pressure is required during the post-purge, then the post-purge procedure is completed independently of the specified time interval and then the control pressure increase is carried out.

In conclusion, an exemplary embodiment of the characteristic transport device according to the invention can be described as follows:

When transporting powdery or granular material through the transport hose from the container to the consumer, e.g. the transport of dry plaster to the plastering machine, the transport air will be blown through the transport hose even after the material has been delivered from the air tank, in order to remove residual the material was removed by subsequent blowing. This prevents lagging or clogging of the transport hose during idle time, i.e. when the material is not being transported.

In a transport device that works in this way, a clock mechanism can be provided which, after closing the shut-off valve between the container and the transport hose, maintains the compressor to obtain compressed air and transport the material through the transport hose in the post-blowing drive within a certain time interval.

Claims (24)

1. A transport device that transports powdery or granular material, such as plaster, from the tank (1) through the transport hose (3) to the consumer (2), with a compressor (4) for producing compressed air to transport the material, and with a shut-off valve (10) ) between the container (1) and the transport hose (3), indicated by the fact that a connecting article with a clockwork mechanism is provided, which, after closing the shut-off valve (10), manages the further transport of air for transport in a certain time interval. 2. Transport device according to claim 1, characterized in that a device (18) is provided for monitoring the pressure in the transport hose (3), e.g. a pressure switch, and that this pressure monitoring device (18) is appropriately connected via control with shut-off valve (10), whereby the shut-off valve (10) is closed, when the set maximum pressure is exceeded. 3. Transport device according to claim 1 or 2, characterized in that the compressor (4) is connected via the valve (14), primarily via the return valve, to the pressure tank (8), which is connected to the stop valve (10). 4. Transport device according to claim 3, characterized in that there is a pressure booster (7) between the compressor (4) and the pressure tank (8). 5. Transport device according to one of claims 1 to 4, characterized in that the compressor (4) is connected via a pipe (5) to the tank (19. 6. Transport device according to claim 5, characterized in that the connecting pipes (5 and 6) from the compressor (4) to the tank (1) and to the pressure tank (8) are connected to each other via the pipe (15) with the valve 816), there, the anti-pressure valve with the closing direction from the pipe (6) towards the pressure tank (8) to the pipe (5) towards the tank 81) is primarily used. 7. Transport device according to one of claims 1 to 6, characterized in that a further device (17), a second pressure switch, is provided for controlling the pressure in the transport hose 83), which controls a certain lower pressure. 8. A transport device according to one of claims 1 to 7, characterized in that the consumer (2) has a measuring device (20) in the filling funnel (21) which gives the transport device control plant a signal for material supply. 9. Transport device according to one of claims 1 to 5, characterized in that in the pipe (5) from the compressor (4) to the tank (1) and in the transport hose (3) between the compressor (4) and the pressure valve (10) provided for each one pressure valve (12, 13), which can be controlled. 10. Method for transporting powdery or granular material, from the container to the consumer using air for transport in the transport hose, characterized by the fact that after the interruption of the supply of material from the container through the transport hose, the transport of air for transport in the transport hose is maintained. 11. The method according to claim 10, characterized in that the transport of transport air is maintained at a certain time interval. 12. The method according to claim 10 or 11, characterized in that the air pressure for transport is monitored and that when the predetermined limit value is exceeded, the supply of material from the tank to the transport hose is interrupted. 13. The method according to one of claims 10 to 12, characterized in that the disconnection between the tank and the transport hose is controlled by means of compressed air from the pressure tank and that the predetermined minimum pressure is controlled in the pressure tank. 14. The method according to claim 13, characterized in that the transport of air for transport is interrupted, if the minimum pressure is not reached after a certain time interval. 15. The method according to one of claims 10 to 14, characterized in that if upon receipt of a signal for a request for material supply from the consumer, the transport of air for transport begins, if necessary after a time delay and the supply of material from the tank to the transport hose follows. 16. The method according to claim 15, characterized in that after the beginning of air transport, a certain time interval passes and that, if the certain pressure is not exceeded during that time interval, the supply of material from the tank to the transport hose begins. 17. The method according to one of claims 15 or 16, characterized in that upon receiving a signal to stop the transport of material from the consumer, air for transport is still transported in a predetermined time interval, even if the supply of material from the tank to the transport hose is interrupted. 18. The method according to claim 17, characterized in that when during transport the transport pressure is below a certain value and no stop signal comes from the consumer, then due to the lack of material, the transport air is transported only in a certain time interval through the transport hose. 19. The method according to one of claims 10 to 18, characterized in that if during the transport phase the pressure in the transport hose falls below a certain value, after the end of the transport phase and the subsequent additional filling, the pressure in the tank rises to a certain value. 20. The method according to one of claims 10 to 19, characterized in that if during the transport phase the pressure in the transport hose increases above a certain value, the pressure in the tank decreases. 21. The method according to claim 20, characterized in that the reduction of pressure in the tank occurs by releasing air through the transport hose. 22. The method according to one of claims 12 to 21, characterized in that if, after interruption of the supply of material from the tank to the transport hose, the pressure in the transport hose falls in a certain time interval below a certain maximum value, the connection will be re-established. 23. The method according to one of the claims 10 to 22, characterized in that if after the end of the transport of transport air, which is for example produced by a compressor, in any case the open connection between the tank and the transport hose is closed, and that takes the air from the tank through the transport hose in a certain time interval. 24. The method according to one of claims 10 to 23, characterized in that after the device is plugged in, air is first transported for a certain time interval, in which the existing pressure in the transport hose lies in predetermined upper and lower values.