EP0291829B1 - Hopper for a pneumatic suction or pressure conveyor system - Google Patents

Abstract

The hopper is intended for pneumatic suction or pressure conveyor systems, in particular for waste-disposal vehicles having a monitoring means, the hopper being connected via a line to a pump/compressor provided with a driving motor and a suction line for receiving and conveying liquid, sludgy, dusting or otherwise free-flowing media being connected to the hopper. In order to maintain the vacuum which has carried out the suction or the pressure which has been applied during pressing out with essentially uniform waste-disposal operation corresponding to optimum speed, to reduce the safety risk considerably and to make the hopper simple and cost-effective to operate using the monitoring means and also to reduce environmental pollution in the case of such a hopper, there is arranged in the line (2) between the hopper (1; 1.1; 1.2) and the pump/compressor (4) a four-way valve (3) whose outlets (3.1; 3.2; 3.3; 3.4) are connected to the suction pipe (4.1) of the pump/compressor (4), to the line (2) to the hopper (1; 1.1; 1.2) and to the pressure pipe (4.2) of the pump/compressor (4), whereas the fourth outlet ends freely, the driving motor (5) of the pump/compressor (4) is designed to have adjustable speed and is provided with means (5.1) for changing over the speed, and a pressure-measuring device (6) having at least two switching contacts is arranged on the line (2) between the hopper (1; 1.1; 1.2) and the four-way valve (3), the switching contacts being connected via lines (6.1; 6.2) to a switching box (7), which in turn is connected to the means (5.1) which adjust the speed of the driving motor (5). Figure 1 is proposed for the publication. <IMAGE>

Description

The invention relates to a receptacle for vacuum suction and pressure systems with a monitoring device, the receptacle being connected via a line switchable from suction to pressure operation to a pump / compressor provided with a drive motor, the line having a four-way valve, the outlets of which are connected to the suction port of the pump / compressor, the line to the receptacle and the pressure port of the pump / compressor, while the fourth outlet ends freely, and a suction line is connected to the receptacle for receiving and conveying liquid, muddy, dusty or free-flowing media .

Such receptacles are used for disposal purposes in order to suck the media to be disposed of in liquid, muddy, dusty or free-flowing form into the container via the suction line and to store them there. After filling the container, these media are discharged via an emptying nozzle or through an openable container flap. if necessary with the help of an ejection piston. The container must be large enough to hold the media, it must be capable of being placed under the appropriate negative pressure and it must be placed under considerable excess pressure, particularly when using an ejection piston or when connecting a pneumatic delivery line to the emptying nozzle. In addition to stationary receptacles of this type, there are also receptacles which, mounted on vehicles, allow the accommodated media to be transported to the emptying point.

Such a receptacle for vacuum suction and pressure systems, which is connected via a line switchable from suction to pressure operation with a pump / compressor provided with a drive motor, a four-way valve being provided in the line, the outlets of which are connected to the suction port of The FR describes the pump / compressor, the line to the receptacle and the pressure port of the pump / compressor, while the fourth outlet ends freely, and a suction line is connected to the receptacle for receiving and conveying liquid, muddy, dusting or free-flowing media -PS 2 413 509; the container is placed in a switching position of the four-way valve by means of a pump under vacuum for sucking in liquid medium via a suction line, while after switching over the four-way valve the same container can be pressurized to over the absorbed medium to deliver a drain line again.

The pumps used have different vacuum or pressure capacities depending on the type and type. The performance for full working operation is given by the nominal speed of the pump. This full workload is not required in all operating modes. In practice, the speed of the drive motor of the pressure / suction unit is set by the operating personnel by hand, for example, using a hand throttle or the like. set. Only in favorable but rare cases is the operating option for speed adjustment within easy reach, the operating personnel must always pay attention to the speed and devote yourself to the speed setting. This additional load leads to distraction of the operating personnel for the other work and operating necessities and may also endanger the personnel or the environment.

This results in the object on which the invention is based, according to which a receptacle with a monitoring device of the aforementioned type is to be specified, in which the vacuum causing the suction or When the pressure is applied, the pressure can be maintained at a substantially constant speed, which corresponds to the disposal task, without additional stress or distraction of the operating personnel, that the safety risk is considerably reduced and that the operation of the receptacle by the monitoring device is simple and economical, and moreover, the environment - and environmental pollution are reduced.

This object is achieved by the features specified in the characterizing part of claim 1, advantageous refinements and developments are described in claims 2 to 15.

The four-way valve in the line leading from the tank to the pump / compressor makes it easy to switch from suction to pressure, with just a single movement. The four-way valve connects either the suction port or the pressure port of the pump / compressor to the free atmosphere, while the other of the two is connected to the receptacle via the line. The vacuum or overpressure is monitored by a pressure measuring device, which is operatively connected to the speed changeover via limit contacts and, when the maximum contact (maximum overpressure or maximum vacuum) is reached, causes the speed to be switched over to a speed that is between the nominal speed for maximum performance and the idle speed. This speed, which can be switched on in this way, can be specified by the operating personnel, in accordance with the disposal task to be solved. When the maximum value is reached, the nominal speed of the pump is reduced to the preset speed until the pressure or vacuum has decreased so far that the minimum contact is reached.

With this preset speed, a "swinging" of the speed between the nominal speed and idling with considerable noise pollution of the environment is avoided, since the environment is annoyed more and more by the constantly occurring noise peaks than by a constant noise of an essentially constant speed, which is essentially only at extraordinary events (eg suction or air bubbles) must be increased to the nominal speed. In normal operation, the drive motor and pump run at the low speed which is adapted to the present disposal, which in addition to a reduction in noise emissions also results in a reduction in wear.

Hydraulic motors can be provided as drives for the pump / compressor as well as electric motors or internal combustion engines. In hydraulic motors, the speed can be adjusted accordingly by adjusting the hydraulic flow via a hydraulic valve with an adjustment drive. Electric motors are either pole-changing three-phase motors or speed-adjustable motors with corresponding ballasts (phase gating control, variable resistors), whereby either the pole switching or the adjustment of the phase-determining resistance or the variable resistance is carried out by the adjusting drive. When using internal combustion engines, the fuel supply is brought to the value necessary for this speed by the means adjusting the speed, the adjusting drive acting on the injection pump or the carburetor. It is advantageous to design the adjustment motor as a stepper motor, since fixed speed stages can be preselected by the number of steps. The introduction of a time delay in the adjustment drive (the time delay being synonymous with a reduction the adjustment speed) causes a delayed transition of the speed and thus a delayed start-up or a delayed shutdown with corresponding slow transitions of the noise level.

In order to enable manual control, push-button contacts are provided on the switch box in parallel with the switch contacts of the contact manometer and interact with the means switching the speed or with their adjustment drives. The insertion of an emergency switch allows the pump / compressor drive to be stopped in the event of danger. Signaling by optical signals in normal operation with a changed color or flashing frequency during the transition to maximum operation and finally again after changing the color and / or flashing frequency in the event of an emergency stop allows the operating state to be recognized remotely.

The further development of the circuit as a follow-up circuit allows fully automatic operation both in the suction state (vacuum) or during emptying (excess pressure). The sequential circuit assumes the maximum state, which triggers the speed down to the operating speed. If the overpressure does not drop within a specified time or the vacuum does not fill up, the emergency stop switch is activated and the drive is shut down. Afterwards, if the pressure conditions still remain in the maximum range, vacuum breakers and / or overpressure blow-off devices are finally activated and the corresponding valves are opened. In order to quickly reduce the particularly critical overpressure, a rupture disk can also be provided as the last stage, which is designed in such a way that it can just safely withstand the maximum pressure permitted for the receptacle, but tears when this pressure is exceeded. To make sure it rips apart, that's it Destroy with a detonating pill, triggered advantageously as the last step of the sequential circuit.

For receptacles with suction chamber and pressure chamber, which are separated from an ejection piston, there is a risk when emptying that the ejection piston is accelerated and ejected by the overpressure in the pressure chamber in the direction of the open container end. To prevent this, safety locking cams which can be actuated from the outside are provided near the openable end of the suction chamber and are triggered by the last stage of the sequential circuit so that they can be pushed into the path of the ejection piston. The cams protruding into the lumen of the receptacle after the release serve as a stop for the ejection piston moving in the direction of the container opening and have the task of stopping this piston. Since the kinetic energy of this piston can take on considerable values, these safety locking cams must be anchored accordingly firmly to the container, the ejection piston being designed in such a way that the ejection piston is deformed when it strikes the safety locking cams and through the deformation is deformed so that its movement in the receptacle is blocked by friction or tilting.

In a receptacle, which is designed in particular as a two-chamber receptacle with an ejection piston as a partition that can be moved between the pressure chamber and the suction chamber, it is proposed as an advantageous embodiment that both for the pressure chamber and for the suction chamber in the region of the container apex, a nozzle is provided and each of the Nozzle has a shut-off valve. This means that each chamber can be shut off individually, regardless of the switching of the four-way valve. If the connecting line is connected to the suction port via the four-way valve, Opening the valve assigned to the suction chamber, the suction operation for receiving the media to be disposed of can be carried out. It is also advantageous to open the valve assigned to the pressure chamber in order to prevent the discharge piston from being displaced by the overpressure (prevailing relative to the suction chamber). For emptying, the four-way valve is switched to pressure mode and the valve assigned to the suction chamber is closed. Via the valve assigned to the pressure chamber, the compressed air flows from the compressor into the pressure chamber via the four-way valve; the discharge piston can move towards the end of the container under the effect of the excess pressure. It does not matter whether the ejection takes place via the open container lid or through the opened emptying nozzle. Pressure relief is provided both by the opened container lid and by the opened emptying nozzle, so that pressure build-up in the suction chamber, which leads to pressure equilibrium (and thus to piston stoppage), is prevented. After emptying, the discharge piston must return to its old position. To do this, the four-way valve is switched to suction mode and, when the valve associated with the suction chamber is closed, the valve associated with the pressure chamber is opened. The negative pressure that arises in the pressure chamber moves the suction piston back into its rest position.

Fig. 1

das Schaltschema eines einfachen Aufnahmebehälters mit Überwachungsvor-richtung und

Fig. 1a

das Schema eines Zweikammerbehälters mit Ausstoßkolben, vorbereitet für die gleiche Überwachungseinrichtung

The essence of the invention is explained by way of example with reference to the accompanying figures. Show

Fig. 1

the circuit diagram of a simple receptacle with monitoring device and

Fig. 1a

the diagram of a two-chamber container with ejection piston, prepared for the same monitoring device

1 shows a single-chamber container 1 with a connected monitoring device. The single-chamber container 1 - which can also be mounted as a container on a vehicle - is provided with an openable cover 1.5 and has an emptying nozzle 1.3 at the lower end of the cover or bottom of the container, which is closed by a valve. For emptying, either the valve of the emptying nozzle 1.3 is opened or the entire cover 1.5 is opened (with hinges and cylinders, not shown). A suction dome 1.9 with a suction hose connection is provided on the top of the container, the connected suction hose being guided, for example, over an extension arm or being able to be unwound from a horizontally lying suction hose reel arranged on the connection. A vacuum breaker or pressure relief valve 1.8 is also provided on the container and can be operated remotely. A nozzle 1.7 is also provided, which is closed with a rupture disk. The container 1 is connected via line 2 to a four-way valve 3. Arranged in the train of the line is a contact manometer 6, the limit contacts for pressure and / or vacuum, each equipped with a maximum and a minimum contact, are connected to the switch box 7 via the lines 6.1 and 6.2. The connecting line 2 is connected to the connector 3.2 of the four-way valve, the connector 3.1 is firmly connected to the suction port of the pump 4 and 3.3 to the pressure port of the pump 4. The fourth connection piece 3.4 opens freely into the atmosphere. Depending on the position of the chick, there is a direct connection from the atmosphere to the suction port 4.1 or from the pressure port 4.2 to the atmosphere. While in the first case air can be sucked in from the atmosphere for the pressure operation, in the second case the air sucked out of the container 1 is expelled into the vacuum for the suction operation.

The pump / compressor 4 is driven by means of a drive motor 5 via a reduction gear 5.3, which permits a rough adaptation of the nominal motor speed to the nominal pump speed. The operating speed is selected using means for setting the speed 5.1, a drive 5.2 making it possible to adjust the operating speed to the (maximum) nominal speed. The operating speed can be pre-selected on the setting means for the respective disposal case.

The control is in principle carried out by the contact manometer 6, the maximum and minimum contacts of which give switching impulses to the switch box 7 either only for vacuum or for both pressure and vacuum via lines 6.1 and 6.2. Parallel to the maximum and minimum contacts are the buttons 7.1, which allow manual intervention in the automatic system. The switch 8 can also be used for manual operation only, by means of which the automatic system can be switched off. Finally, an emergency stop switch 7.2 is connected to the switch box, it goes without saying that a plurality of electrically switched emergency stop switches can be provided, which are arranged in such a way that they can be easily reached by the operating personnel during normal operation of the receptacle. When the minimum contact is reached (either by dropping the overpressure or by increasing the underpressure), the actuator 5.2 for the means for speed change is activated via the switch box 7, the speed change switches in steps with a delay or the drive motor 5 switches from operating speed to nominal speed by slow transition. Due to this run-up, including the suction vacuum pump, the pump output is increased, the pressure gauge moves in the direction of maximum contact. If this is reached, another pulse goes to the switch box 7, which reverses the speed change again makes. If the pressure does not follow the reduced speed, e.g. due to a malfunction, the emergency stop is activated and the pump drive is shut down. If this does not cause a change in the limit state either, the vacuum breaking valve or the pressure relief valve 1.8 is opened, thus forcing a change in the limit state. Should this valve also fail, the rupture disk 1.7 (unless it has burst due to the overpressure reached) is finally destroyed by mechanical action, for example by means of a detonated detonating pill.

Fig. La shows the receiving container 1, which is designed here as a two-chamber container. The discharge piston 1.4 separates the pressure chamber 1.2 from the suction chamber 1.1. The suction chamber 1.1 serves to collect the media to be disposed of, while the pressure chamber 1.2 is essentially responsible for the ejection and movement of the ejection piston 1.4. Both lines are connected to line 2 via shut-off valves 2.1 and 2.2. The connection for the suction hose 1.9 is of course in the area of the suction chamber 1.1. Both chambers are provided with the remotely operable vacuum break or pressure relief valves 1.8 near the end position. In the two-chamber design of the receptacle, safety locking cams 1.6 that can be inserted into the interior of the container are provided on the side of the openable container lid 1.5, near the end of the container. These locking cams - also remotely operated - have the task of stopping the ejection piston 1.4 that is in motion before it emerges from the receptacle 1.

Claims (15)

1. Container for vacuum suction and pressure plants with a monitoring device, said container (1; 1.1; 1.2) being connected via a line (2) switchable from suction operation to pressure operation to a pump/compressor (4) provided with a drive motor (5), said line (2) having a four-way valve (3), the outlets (3.1, 3.2, 3.3, 3.4) of which are connected to the suction fitting (4.1) from the pump/compressor (4), to the line (2) leading to the container (1; 1.1; 1.2), and to the pressure fitting (4.2) of the pump/compressor (4), the fourth outlet terminating freely, and with a suction line being connected to the container for receiving and delivering liquid, sludgy or pourable media, characterised in that the drive motor (5) from the pump/compressor (4) is adjustable, the adjustable speed lying between full load and no load and being preselectable, and in that a pressure gauge (6) having at least two switching contacts is mounted to the line (2) between the container (1; 1.1; 1.2) and the four-way valve (3), the switching contacts being connected via lines (6.1, 6.2) to a switch box (7), which in its turn is connected to means (5.1) for adjusting the speed of the drive motor (5).
2. Container according to Claim 1, characterised in that a hydraulic motor is provided as drive motor (5) for the pump/compressor (4), the means (5.1) for adjusting the speed of said hydraulic motor having the form of a hydraulic valve with an adjusting actuator (5.2).
3. Container according to Claim 1, characterised in that a variable speed electric motor is provided as drive motor (4) for the pump/compressor (4) which is preceded by speed adjusting means (5.1) with a drive/controller (5.2).
4. Container according to Claim 1, characterised in that an internal combustion engine is provided as drive motor (5) for the pump/compressor (4), the speed adjusting means (5.1) of said internal combustion engine having the form of an injection pump or carburettor provided with an adjusting actuator (5.2).
5. Container according to any one of Claims 2 to 4, characterised in that an adjusting motor, preferably a step motor is provided as adjusting actuator.
6. Container according to any one of Claims 2 to 4, characterised in that the adjusting actuator is in the form of a lifting magnet.
7. Container according to any one of Claims 2 to 5, characterised in that the adjusting actuator is provided with an adjustable time delay.
8. Container according to any one of Claims 1 to 7, characterised in that the switch box (7) to the switching contacts of the pressure gauge (6) has touch contacts (7.1) arranged in parallel.
9. Container according to any one of Claims 1 to 8, characterised in that at least one emergency stop switch (8) cooperating with the drive motor (5) or the speed adjusting means (5.1) thereof is provided, said emergency stop switch (8) preferably being looped via the switch box (7).
10. Container according to Claim 8 or 9, characterised in that at least one optical and/or acoustic alarm is provided which is capable of indicating when at least the maximum values of vacuum or pressure have been reached.
11. Container according to Claim 8, 9 or 10, characterised in that the switch box (7) comprises a sequence control, through which, upon actuation of the maximum limit contact of the pressure gauge (6) or of the touch contact (7.1) arranged in parallel thereto, initially the speed can be controlled, then the emergency stop switch can be actuated and then a vacuum interruption valve provided on the container (1) or a vacuum interruption valve provided on the suction chamber (1.1) and a pressure relief valve provided on the pressure chamber (1.2) can be opened.
12. Container according to any one of Claims 6 to 11, characterised in that the container (1) is at least on the side of the pressure chamber (1.2) provided with a bursting disk (1.7) preferably destructable in connection with the emergency stop by means of the mechanical impact of e.g. an explosion pill.
13. Container according to any one of Claims 1 to 12, in particular a two-chamber container with an ejection piston as a baffle shiftable between the suction chamber and the pressure chamber, characterised in that the container (1) is provided with two connection fittings, each fitting being arranged in the area of the container apex close to both ends of the container (1) and both connection fittings being connected via stop valves (2.1, 2.2) to the line (2) connecting the container (1) with a pump/compressor (3).
14. Container according to Claim 13, wherein the end of the suction chamber is closed with a detachable lid, characterised in that safety lock cams are provided, which are externally actuated and can be slided into the lumen of the suction chamber (1.1) and block the path of the ejection piston (1.4).
15. Container according to Claim 14, characterised in that the safety lock cams can be triggered by remote control, the sequence control provided into switch box (7) having a further switching step for triggering the safety lock cam.

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