HK1174888B - Waste emptying control - Google Patents

Description

Waste evacuation control

Technical Field

The present invention relates generally to pneumatic material transfer systems from a stockpiling point to a gathering point, and more particularly to emptying temporary storage spaces of such systems through associated discharge valves.

Background

Pneumatic systems are mainly vacuum operated systems, currently used for collecting and transporting various types of materials, such as general household waste, kitchen waste, laundry waste water and other waste fractions. Contemporary material collection systems of this type have a temporary storage space for the accumulated material and a discharge valve that controls the emptying of the space, and the operation of the discharge valve typically takes a fixed preset time to control the open state of the valve. When the system is continuously operating, the initially defined and set discharge valve opening time will sometimes become less than optimal and thus require adjustment to maintain effective emptying, in turn optimizing system operation.

In fact, it can be seen that the preset opening times of the discharge valves currently used often require some manual analysis and intervention and do not fully cater for the systems to which they are applied. This is due in part to the perturbations and variations that occur in the operating characteristics of the system. Variations in time, material type, season, etc. and too low a set time will cause undesirable disturbances, since the valve cycling and closing required to close the valve is time consuming. Similarly, too high a set time will result in long operating times and increased energy consumption.

Disclosure of Invention

It is a general object of the present invention to provide an improved emptying sequence control in a pneumatic material collecting and conveying system.

In particular, it is an object of the invention to propose a method for improving the emptying sequence controlling the system, thereby improving the emptying efficiency, reducing the operating time and reducing the energy consumption of the system.

In particular, another object of the invention is to propose an improved control device for such a system, so as to improve the efficiency of the emptying sequence of the system and to reduce the consumption.

These and other objects of the invention will be defined by the appended patent claims.

The present invention relates to a pneumatic system for collecting and conveying stacked material. In particular, it relates to such a system which uses air flow to convey material from a stockpile point storage space, wherein emptying of the storage space is performed by opening a discharge valve downstream of the storage space. To achieve an optimized storage space discharge cycle, the basic idea of the invention is to detect the emptying state of the storage space when the discharge valve is open, to monitor, record and evaluate the output from at least one emptying state sensor and to control the discharge valve opening time in dependence on the sensor output, and to close the discharge valve when the sensor output indicates that the storage space is in an empty state. This optimizes the emptying cycle for each storage space and the emptying sequence of the entire system.

In another aspect of the invention, an improved apparatus for control of an evacuation cycle of a temporary storage space of a pneumatic material collection and delivery system is provided wherein a flow of air delivers windrow material from the storage space through a downstream discharge valve. This apparatus includes a control system having emptying logic and valve actuator control means for controlling the opening and closing of the discharge valve. The basic idea of the invention is that the device further comprises at least one sensor for detecting the emptying state of the storage space during the opening state of the discharge valve; means for evaluating an empty state sensor output; and means for calculating the opening time of the controlled valve based on the monitored and evaluated output of the empty condition sensor, whereby the discharge valve is closed when the monitored and evaluated output of the empty condition sensor indicates an empty condition of the storage space. The control device of the present invention provides excellent conditions for each storage space to perform an effective discharge cycle, thereby providing an effective emptying sequence to the entire pneumatic material collection and delivery system.

Further preferred developments of the basic inventive idea and its embodiments are specified in the dependent subclaims.

Advantages offered by the present invention in addition to those described above will be readily appreciated upon reading the detailed description of embodiments of the invention.

Drawings

The invention, together with further objects and advantages thereof, may best be understood by making reference to the following description, taken in conjunction with the accompanying drawings.

FIG. 1 is a schematic view of a pneumatic waste collection system of the stationary type, and including a waste accumulation point variation to which the present invention may be applied;

FIG. 2 is a partially schematic illustration of a first embodiment of a waste accumulation point variation of the system of FIG. 1 in which the invention is practiced;

FIG. 3 is a similar view of a second embodiment of another waste accumulation point variation of the system of FIG. 1 with which the invention is practiced;

FIG. 4 is a similar view of a third embodiment of other waste accumulation point variations of the system of FIG. 1 to which the present invention is practiced;

FIG. 5 is a schematic view of an evacuation cycle control arrangement of the present invention;

FIG. 6 is a schematic flow chart diagram of an embodiment of an evacuation cycle control method in accordance with the present invention;

FIG. 7 is a very schematic illustration of a mobile waste collection system to which the present invention may be applied; and

figure 8 is a partially schematic illustration of another waste accumulation point variation of another practice of the invention applied to a pneumatic waste collection system.

Detailed Description

The present invention will be described with reference to the exemplary embodiments of the evacuation cycle control illustrated in fig. 2-9. These figures relate to the use of the present invention in a conventional vacuum waste collection system. It should be emphasized, however, that the drawings are for purposes of illustrating preferred embodiments of the invention and are not intended to limit the invention to the details thereof. The inventive concept can be applied with only minor modifications to most types of pneumatic collection and conveying systems, such as systems intended to collect general household waste, kitchen waste and different waste fractions, and pneumatic systems for collecting and conveying e.g. laundry waste water and other materials. It should also be emphasized that the use of the terms "stockpiling point", "temporary storage space" and "discharge valve" throughout the specification and claims should not limit the present invention to any particular type of system or system configuration. Thus, the term "stockpiling point" shall include any type of manual or automatic feeding device, the term "temporary storage space" shall include any type of intermediate storage device, regardless of size and shape, in a material collection and transfer system, and the term "discharge valve" shall include any type of device for opening and closing an outlet of a storage space in communication with a transfer pipe of the system.

Modern vacuum operated waste treatment typically involves temporary storage of accumulated waste in the system in a storage space located suitably close to the point of accumulation, as discussed in the introductory part of the specification. Much work has been done and is being done in the art with the goal of optimizing the system purge sequence. Due to these efforts, it is known to monitor the filling level of the temporary storage spaces by means of various types of sensors and to determine the emptying sequence of the individual storage spaces or groups thereof on the basis of one or more parameters. These parameters may vary from just the fill level of the storage space to a hybrid combination of system placement, system settings, and system performance or occupancy. Much work has also been done to facilitate and speed up the actual emptying cycle of the storage space. This means that the current pneumatic waste disposal is quite advanced in the category of emptying sequences involving different associated branches and accumulation points of the whole system and reliable emptying of the individual storage spaces. However, it has now been appreciated that current system operation does not adequately account for the dead time present in each storage space evacuation cycle. Dead time is the time that the storage space discharge valve remains open after it has been sufficiently emptied. Dead time is due to the fact that the emptying cycle of each storage space is conventionally based on a calculated and fixed emptying time that is not automatically and continuously updated as the conditions of the system change, so using a preset emptying time will unnecessarily slow down the emptying sequence of the system.

In order to overcome the above-mentioned drawbacks and problems with the operation of the known systems, the present invention now proposes a new method for optimizing the operation of the whole system by monitoring and controlling the emptying cycles for the individual storage spaces. According to the invention, the actual emptying state of each storage space is taken into account when determining the actual opening time of the associated discharge valve. This will enable time efficient operation of each discharge valve, enabling the next storage space emptying cycle in the system emptying sequence to begin after the previous storage space has been effectively emptied, rather than after a predetermined time. This improvement is therefore clearly not only attributable to the emptying sequence of the aging system, but also to the cost reduction due to the fact that the vacuum source operation reduces the overall effective time by reducing the relationship in which the system management will no longer need to be periodically adjusted due to the discharge valve opening time. In this regard, it should be clarified that the term emptying state as used herein generally refers to the actual amount of collected material remaining in the storage space during an emptying cycle.

As mentioned above, fig. 1 schematically illustrates an example of a conventional vacuum waste collection system 1, i.e. of the stationary type, in which waste accumulated at a stockpiling point is transported in a waste transport pipe system TP to a closed tank or container (not specifically illustrated) of a central waste collection terminal CT. In this system 1, a plurality of stacked spot variants 2, 3 have been shown; 102. 103; 202. 203; 302. 303, serve to illustrate that the present invention is applicable to most fixation system variations. The accumulation point can thus be of almost any conventional type, including the insert chutes 3, 103, which extend from the multistorey buildings B1, B2 and usually have waste inlets 2, 102 at each floor, or separate or individual so-called "trash bin" types of inserts 203, 303, which are positioned at a convenient level for inserting waste by being installed outdoors and likewise having at least one waste inlet 202, 302 positioned when the user is standing on the ground. The accumulation points 3, 103, 203, 303 are each associated with a storage space 5, 105, 205, 305 communicating with the transport pipe system TP through a controlled discharge valve 10, 110, 210, 310 arranged downstream of the storage space.

The storage space 5, 105, 205, 305 is used for temporarily storing the piled waste until the next emptying cycle. The storage space has various forms and may be formed by the lower part 5 of the actual multi-level chute 3, or an expanded lower part thereof, a curved lower section of the multi-level chute 105, the lower part 305 of the curved tube of the "trash" type insert 303 being connected to the transfer pipe TP, or by the space 205 formed in the actual "trash" type insert 203.

FIGS. 2-4 illustrate waste accumulation points 2, 3 for the system 1 of FIG. 1; 102. 103; 202. 203; 302. 303 is applied to more details of the first to fourth embodiments. In particular, fig. 2 relates to a multi-level waste chute 3 in building B1, and to the inventive proposal of providing at least one sensor 6, 7 to detect waste remaining in the storage space. In this case, two first and second, or upper and lower, sensors 6, 7 are provided spaced apart from each other at the lower portion of the chute 3 forming the temporary storage space 5. Downstream of the storage space 5, a discharge valve 10 and its drive 14 are provided. The emptying of the storage space 5 is thus controlled by means of the discharge valve 10, which in the open state conveys the emptied waste material to the transport line TP via the connecting line 16.

The emptying state sensors 6, 7 are provided to detect the actual emptying state of each storage space 5 during the open state OC (fig. 6) of the discharge valve 10. Although the sensors 6, 7 of the present invention can be designed very similar to the prior art fill level sensors, they each use two completely unique approaches. According to the invention, the emptying state sensor is not used as in the previous invention for determining when emptying should be started, but instead for detecting when the associated storage space has been sufficiently emptied, so that the discharge valve can be closed again and the next storage space emptying cycle in the system emptying sequence can be started as soon as possible. As mentioned above, two sensors 6, 7 are illustrated in the embodiment of FIG. 2, but it should be emphasized that the present invention is not limited to the use of any particular number of sensors. The actual number of sensors may vary depending on a number of conditions, such as sensor type, chute type, material pieces, etc. In advantageous conditions, only one suitable type of sensor may be required, and in extreme cases, even more than two sensors. The actual type of sensor used may equally well depend, for example, on the conditions prevailing and may comprise digital and/or analogue level sensors, mechanical and/or ultrasonic and/or infrared type sensors. The output from the sensors 6, 7 is shown in fig. 2 as being transmitted to control system emptying logic CSEL, which will be described more closely below in connection with fig. 5, and which controls the operation of the actuator 14 for the discharge valve 10.

Figure 3 relates to the two types of accumulation points of figure 1, in the form of a multi-level waste chute 103 and associated inlet 102 in building B2, and a "trash bin" type insert 303 and associated inlet 302, respectively. Common to the stacking point variants is that in each case a storage space 105, 305 is formed in a chute/pipe bend 105A, 305A, which chute/pipe bend 105A, 305A is connected at one end to the lower end of the chute 103 and the insert 303, respectively, and at the opposite end to a connecting pipe 116, 316, which connecting pipe 116, 316 transports the emptied waste material to the transport pipe TP. The discharge valve 110, 310 is likewise arranged downstream of the storage space 105, 305, more specifically in the generally horizontal section of the connecting line 116, 316, together with its drive 114, 314. The illustrated first and second sensors, 106, 306 or upper and lower sensors, 107, 307 are disposed in spaced relation to one another adjacent the chute/pipe bends 105A, 305A, respectively, that form the temporary storage spaces 105, 305. In particular, in the illustrated embodiment, the first sensor 106, 306 is positioned directly at the level of the lower end of the slideway 103 or at the upper part of the insert 303, and the second sensor 107, 307 is positioned in both cases slightly beyond the longitudinal midpoint of the bend 105A, 305A. However, these positions are merely illustrative, and the actual positions may vary, for example, depending on the above conditions, which also determine the number of sensors used. All other considerations discussed above with respect to the sensor of fig. 2 are also valid for these stack point variants.

Fig. 4 illustrates a further variant of the accumulation point according to fig. 1, this variant being formed by another type of "trash" type insert 203 with an inlet 202. In this case, the storage space 205 is formed by an actual "waste bin", the downstream of which is in direct communication with a connecting pipe 216 of the conveying pipe TP via the discharge valve 210 and its drive 214. First and second, or upper and lower, sensors 206,207 are provided spaced from one another as before, with the first sensor 206 also preferably being provided at an upper portion of the insert 203, and the lower sensor 207 being positioned slightly above or upstream of the discharge valve 210. Similar to the foregoing, all other considerations already discussed above with respect to sensors are valid for these accumulation point variants.

A control arrangement for controlling a storage space emptying cycle and associated method will now be described with particular reference to figures 5 and 6. In particular, fig. 5 illustrates an exemplary control arrangement for controlling an emptying cycle of a temporary storage space of the pneumatic material collection and conveying system 1, wherein an air flow conveys material from the storage space through a controllable discharge valve arranged downstream of the actual storage space. The flow chart of fig. 6 illustrates the relevant emptying cycle control method and, to the extent applicable, the apparatus and method will also be described with particular reference to the accumulation points 2, 3 of fig. 2, but it should be clear that the description applies equally to all accumulation point variants.

The control means essentially comprise the above-mentioned single or multiple emptying state sensors 6, 7, the control system emptying logic CSEL and a control device 19 for controlling the opening and closing of the discharge valve 10 by means of the actuator 14. The sensor or sensors 6, 7 are arranged in connection with the storage space 5 to detect the emptying state of the storage space 5 continuously or at least at very short time intervals during the discharge valve open state OC. The valve open condition OC is achieved by activating the discharge valve actuator 14 when a condition for the commencement of storage space emptying is met, for example in response to an output from a display fill condition controller 8 such as a conventional level sensor.

The output of the emptying state sensor/sensors 6, 7 is input to means 17 for recording and evaluating the emptying state sensor output signals SS1, SS 2. The evaluation may for example preferably relate to a set of empty state periods EST during which the sensor/sensors do not register any waste items present in the storage space to indicate the empty state EC of the storage space. The recorded or monitored and evaluated outputs from the emptying state sensor/sensors are then input to a device 18 for calculating the controlled discharge valve opening time COT to effect closure of the discharge valve 10 by a discharge valve drive control device 19 when the monitored and evaluated outputs from the sensor/sensors 6, 7 indicate the storage space empty state EC and other timing and emptying conditions are met.

Said other emptying conditions are provided in a very schematically shown timer and/or counter or other input means 20. One example of other emptying conditions is a discharge valve timing condition TC, which may comprise a minimum discharge valve opening time OTMIN overriding the calculated opening time COT, depending on the type of waste deposit point 2, 3 and/or the type of controlled discharge valve 10 and/or the type of sensor/sensors 6, 7 applied and/or the type of material collected. Another example would be to set a maximum discharge valve opening time OTMAX for denying interruption of the entire system emptying sequence when the correct empty state EC signal is not received. Other examples of such other conditions may be the addition of an additional storage space purge time ECT which may include an additional discharge valve open time ECT1 for ensuring that the storage space is properly purged and calculated based on the waste fragments and/or the storage space diameter to compensate for the friction of the waste fragments against the walls of the storage space; or additional discharge valve open time ECT2 for compensating for accelerating and transporting material through the horizontal segment of the pipe bend storage space 105, 305 of the accumulation point variation 103, 303 of fig. 3.

FIG. 6 is a flowchart outlining an exemplary method for controlling an evacuation cycle for a temporary storage space in accordance with the present invention. The control method will be initiated after the storage space emptying start condition is fulfilled. The purge start condition may relate to a combination of a predetermined system purge timing control and a fill state sensor output. In a first step S1, after the emptying start condition is fulfilled, emptying of the storage space is initiated by opening the associated discharge valve and by applying a vacuum to the storage space. In step S2, the emptying state of the storage space is detected and monitored by means of the recording signals SS1, SS2 emitted by the single or multiple emptying state sensors or multiple sensors. This sensor signal monitoring is performed during the entire period in which the discharge valve is in its open state OC. In fact, this monitoring can be activated before step 1 and is preferably performed continuously during said valve open state OC.

In step S3, the detected sensor outputs SS1, SS2 are evaluated in the correlating means 17 and the discharge valve opening time COT is calculated and controlled by the correlating means 18 based on the monitored and evaluated outputs of the emptying state sensor/sensors. Monitoring continues in step 4 as long as the sensor input monitoring indicates that the storage space has not reached the empty state condition EC. In the basic embodiment, when the monitored, evaluated and calculated empty state sensor signals SS1, SS2 indicate that the storage space has reached the empty condition EC, the discharge valve will close at step S5 to terminate the empty cycle.

In step S6, the calculated valve opening time COT may in certain situations be overridden by setting the above-mentioned additional storage space purge time ECT, which may include an additional discharge valve opening time ECT1 for ensuring the purging of temporary waste storage spaces of the type disclosed in fig. 2 and 4, where the piled material is stored on a gravity plate discharge valve. As described above, the additional discharge valve open time ECT1 may be calculated, for example, based on the waste fragments and/or the storage space diameter. The additional storage space purge time ECT may alternatively include an additional discharge valve open time ECT2 to compensate for the horizontal storage space segment that accelerates and transports material through a temporary waste storage space of the type disclosed in fig. 3. In other variations of the control method, a discharge valve timing condition TC, such as the minimum discharge valve opening time OT described above overriding the calculated opening time COT_MINAnd/or maximum opening time OT of the discharge valve_MAXAlternatively or additionally in a further step S7.

In the inventive control method, the storage space emptying state is detected and monitored during the discharge valve open state OC by means of a digital and/or analog level sensor and/or by means of a mechanical and/or ultrasonic and/or infrared type sensor as a first emptying state sensor and/or as a second or further emptying state sensor. However any suitable type of existing or future sensor may be used within the scope of the present invention.

Application of the inventive principles to a point of accumulation variation is disclosed in fig. 7, which includes a temporary waste storage space in the form of a waste storage tank 405, the storage tank 405 having an access chute 403 and associated access 402 and optional bottom screw 409. Although the holding tank 405 is illustrated as part of the mobile vacuum operated waste collection system 401, it is shown in the drawings that it may also be associated with a stationary vacuum operated waste collection system of the type described above having a central collection station CT. In the former case, waste is temporarily stored in the waste storage tank 405 and may be intermittently discharged from the tank by a partial vacuum in the transfer pipe TP from the waste storage tank discharge area 405A through the discharge valve 410 to the vacuum cleaner VT. A first or rear empty state sensor 406 is disposed in the upper tank section proximate to the inlet chute 403 and a second or front empty state sensor 407 is disposed in the upper tank section proximate to the tank discharge section 405A. The inventive emptying cycle control described above is also generally applicable to this embodiment, but it is preferred here to incorporate a tank operation control system such as that disclosed in the earlier swedish patent No. 529358C 1. In other variations, the bottom screw 409 is operated to optimize the volume within the can, as described in international PCT application number WO2009038531a 1. In this case, the described control method, and in particular the display of the empty state EC of the storage space, can also preferably be associated with a signal input representing a plurality of forward-directed bottom helical volume optimization operations.

Finally, FIG. 8 illustrates other stacked-point variations to which the present invention may be applied. Here, waste material is deposited in a carousel type inlet 503 comprising a storage space 505 consisting of a plurality of individual compartments (not shown) which can be rotated to bring the inlet (not shown) into position in line with the designated compartments for depositing waste material. When the compartments are ready to be emptied, they are rotated to align with the discharge valve 510 and the empty status sensor 506. The evacuation of each compartment is performed and controlled according to the general control cycle described above.

Alternatively, variant embodiments of the invention of different illustrative character, but not specifically illustrated, may be applied without departing from the general scope of the invention. One example of this is the actual positioning of the evacuation status sensor/sensors of the present invention. Depending on the type of temporary storage space, its shape, size and the point of accumulation associated therewith, the sensor/sensors may optionally be positioned to detect a storage space empty condition. Thus, for example, the sensor may be positioned inside, outside, above or below the storage space.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment. The invention is therefore intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims (10)

1. A method for controlling an emptying cycle for a temporary storage space (5, 105, 205, 305, 405, 505) and a material accumulation point (2, 3; 102, 103; 202, 203; 302, 303; 402, 403; 503) connected thereto of a pneumatic material collection and conveying system (1, 401), which pneumatic material collection and conveying system (1, 401) conveys collected material from said temporary storage space using an air flow, emptying being performed by opening a discharge valve (10, 110, 210, 310, 410, 510) arranged downstream of the temporary storage space, characterized in that:

-detecting a temporary storage space emptying condition when the discharge valve is in an Open Condition (OC); by passing

-monitoring and recording outputs (SS1, SS2) from at least one temporary storage space emptying status sensor (6, 7; 106, 107; 206, 207; 306, 307; 406, 407; 506);

-evaluating an output from the at least one temporary storage space emptying status sensor (SS1, SS 2);

-closing the discharge valve and initiating a next temporary storage space emptying cycle when the monitored and evaluated output of the at least one temporary storage space emptying status sensor indicates that the temporary storage space is in an empty state (EC).

2. The method according to claim 1, characterized in that the discharge valve open time (COT) is calculated from the monitored and evaluated output of said at least one temporary storage space emptying status sensor and an additional preset discharge valve Timing Condition (TC).

3. A method according to claim 2, characterized in that the minimum Opening Time (OT) is set for the discharge valve (10, 110, 210, 310, 410, 510)_MIN) Which overrides the calculated discharge valve opening time (COT) and which is calculated according to the material accumulation points (2, 3; 102. 103; 202. 203; 302. 303; 402. 403; 503) and/or the discharge valve and/or at least one temporary storage space emptying status sensor (6, 7; 106. 107; 206. 207; 306. 307; 406. 407; 506) and/or the type of material collected.

4. A method according to claim 2 or 3, characterized in that for the discharge valves (10, 110, 210, 310, 410, 510) a maximum Opening Time (OTMAX) is set which overrides the calculated discharge valve opening time (COT) when no correct empty state (EC) signal is received.

5. Method according to claim 1, characterized in that the temporary storage space emptying state is detected during the discharge valve open state (OC) by means of a digital and/or analog level sensor (6, 7; 106, 107; 206, 207; 306, 307; 406, 407; 506) and/or by means of a sensor (6, 7; 106, 107; 206, 207; 306, 307; 406, 407; 506) of the mechanical and/or ultrasonic and/or infrared type as first temporary storage space emptying state sensor (6; 106; 206; 306; 406; 506) and/or as other temporary storage space emptying state sensor (7; 107; 207; 307; 407).

6. A method according to claim 1 for controlling the emptying cycle for a temporary storage space (5, 205, 505), where the material deposited is stored on a gravity plate discharge valve (10, 210, 510), characterized by adding an extra discharge valve opening time (ECT1) calculated on the basis of the material fragments and/or the diameter of the temporary storage space for compensating the material fragments against rubbing against the walls of the temporary storage space.

7. Method according to claim 1 for controlling an emptying cycle for a temporary storage space (105, 305), wherein piled material is stored in a pipe bend (105A, 305A) and a discharge valve (110, 310) is positioned in a substantially horizontal pipe section (116, 316), characterized in that an additional discharge valve opening time (ECT2) is added for compensating for accelerating and transporting material through said substantially horizontal pipe section.

8. An emptying cycle control device for a temporary storage space (5, 105, 205, 305, 405, 505) and a material accumulation point (2, 3; 102, 103; 202, 203; 302, 303; 402, 403; 503) of a pneumatic material collecting and conveying system (1, 401) connected thereto, wherein an air flow conveys accumulated material from said temporary storage space through an open discharge valve (10, 110, 210, 310, 410, 510) arranged downstream of the temporary storage space, said control device comprising a control system with emptying logic (CSEL) and valve drive control means (19) for controlling the discharge valve to open and close, characterized in that:

-at least one temporary storage space emptying status sensor (6, 7; 106, 107; 206, 207; 306, 307; 406, 407; 506) for detecting a temporary storage space emptying status during a discharge valve open status (OC);

-evaluation means (17) for evaluating an output (SS1-SS2) from the at least one temporary storage space emptying status sensor;

-calculating means (18) for calculating a valve open time (COT) based on the monitored and evaluated output from said at least one temporary storage space emptying status sensor, whereby said discharge valve is closed and a next temporary storage space emptying cycle is initiated when the monitored and evaluated output from said at least one temporary storage space emptying status sensor indicates a temporary storage space empty status (EC).

9. An apparatus according to claim 8, characterized by setting means (20) for setting a minimum Opening Time (OT) for the discharge valve (10, 110, 210, 310, 410, 510) depending on the type of material accumulation point (2, 3; 102, 103; 202, 203; 302, 303; 402, 403; 503) and/or the type of discharge valve and/or the type of at least one temporary storage space emptying status sensor (6, 7; 106, 107; 206, 207; 306, 307; 406, 407; 506) utilized and/or the type of material collected_MIN) Which overrides the calculated discharge valve open time (COT).

10. Device according to claim 8 or 9, characterized in that the at least one temporary storage space emptying status sensor (6, 7; 106, 107; 206, 207; 306, 307; 406, 407; 506) for detecting the temporary storage space emptying status comprises a first temporary storage space emptying status sensor (6; 106; 206; 306; 406; 506) and in relevant cases other temporary storage space emptying status sensors (7; 107; 207; 307; 407), and that the at least one temporary storage space emptying status sensor is a digital and/or analog level sensor (6; 106; 206; 306; 406; 506) and/or a mechanical and/or ultrasonic and/or infrared type sensor.