EP3053651A1 - Method and device for controlling the amount of air fed to or removed from a safety cabinet - Google Patents

Abstract

The invention relates to a method and a device for controlling the amount of air supplied to a safety cabinet and / or discharged from it. In this case, an exhaust air line (7) and / or air supply line to a cabinet body (2) of the relevant safety cabinet is connected. In addition, signals of at least one sensor (8) arranged in the exhaust air line (7) and / or the supply air line are evaluated for air quantity measurement. With the aid of a control unit (10) connected to the sensor (8), a time-dependent air control takes place in the exhaust air line (7) and / or supply air line.

Description

The invention relates to a method for controlling the amount of air supplied or discharged from a safety cabinet, according to which an exhaust pipe and / or air supply line is connected to a cabinet body of the safety cabinet, and then evaluated signals of at least one arranged in the exhaust duct and / or the supply air sensor for air flow measurement become.

Safety cabinets and in particular hazardous substance cabinets are usually used for receiving and storing liquid or solid hazardous substances, such as chemicals. For this purpose, such safety cabinets are typically equipped with a certain fire resistance and regularly have a so-called self-closing mechanism. The self-closing mechanism ensures that at elevated temperature, for example in case of fire, a cabinet door closes the cabinet body at an access opening reliably.

In the generic state of the art according to the WO 2012/150217 A1 Such a safety cabinet is described, which is additionally equipped with an air guide unit. In addition, the cabinet body has a supply line and a sensor located in the supply line, with the aid of which the amount of air conveyed in the supply line is detected and monitored. Depending on the admission of a media delivery device, the volume of air delivered is varied in the sense of a regulation.

The further prior art according to the DE 10 2012 020 127 A1 deals with an arrangement for monitoring and early fire detection for fire and / or potentially explosive vessels and housings. Individual smoke detectors are combined into modules and connected to each other via a ring bus. In this way, the total detection time of the smoke detectors should be reduced and the desired early fire detection be enabled.

The prior art has proven itself in principle, as far as the bus connection of smoke detectors on the one hand and the control of a safety cabinet supplied amount of air on the other hand in response to a media delivery. However, these are primarily situation-based approaches, ie those that are only used in the generic state of the art when a media delivery takes place. As a result, although the necessary energy for the admission of an associated ventilation arrangement can be partially reduced. However, there is still a high demand for further cost reductions, especially as far as the operating costs of such ventilation arrangements are concerned. The invention aims to remedy this situation.

The invention is based on the technical problem of further developing such a method and a device for controlling the amount of air supplied or discharged from a safety cabinet so that significant energy savings are observed.

To solve this technical problem, a generic method for controlling the amount of air supplied to or removed from a safety cabinet within the scope of the invention is characterized in that a time-dependent air quantity control in the supply air line and / or exhaust air line takes place with the aid of a control unit connected to the sensor. In the context of the invention, therefore, the at least one sensor present in the exhaust air line and / or the supply air line is used for the control or regulation of the amount of air guided through the relevant line, in connection with the control unit connected to the sensor. In this case, the control unit predefines the respective desired amount of air, wherein in connection with the sensor and a control loop formed in this way, the predetermined amount of air is regulated. This can be done in the supply air as well as in the exhaust pipe or in both lines. In this case, according to the invention, the control of the amount of air is performed time-dependent, so there is a time-dependent air quantity control.

In fact, it has proven to be particularly favorable in this context if the time-dependent air quantity control varies an associated ventilation arrangement or the performance of the ventilation arrangement. As a consequence, the amount of air guided through the relevant supply air line and / or exhaust air line also changes. The performance of the relevant ventilation arrangement can be varied, for example, depending on the time of day and / or weekday and / or depending on the date and / or season and / or year. This takes place overall with additional consideration of signals from the sensor, with the aid of the control unit and in the sense of a regulation.

In any case, the control unit is typically equipped with a timer, with the aid of which the time-dependent air control is performed by the performance of the ventilation arrangement undergoes the desired time-dependent variation. For example, it is conceivable that the performance of the ventilation arrangement during working hours in a laboratory to a normal value, the normal power is controlled. In contrast, you will reduce the power to control the ventilation arrangement after work or on weekends or reduced to a lowered power. Comparable variations are possible and conceivable depending on the season, the day of the week, the date etc.

The invention always ensures that, with the aid of the control unit and the sensor, the air control or air volume control is carried out in a time-dependent manner, in that the power of the associated ventilation arrangement experiences a corresponding variation. In this way, the invention takes into account the fact that a maximum supply of supply air to the security cabinet in question or removal of exhaust air is usually required only during a certain number of hours per day and not otherwise. In addition, the time-dependent air control or air volume control takes into account the distinction between working days and weekend days, so that as a result the average (electrical) power for controlling the ventilation arrangement drops significantly. As a result, drastic energy savings are sometimes observed.

In the context of the invention and according to a further advantageous embodiment, a vehicle-specific air quantity control can additionally be carried out with the aid of the control unit. That is, the control unit provides in this case not only for the above-described time-dependent air quantity control in the supply air line and / or exhaust air line, but the air quantity control is supplementary hazardous substances. By this is meant according to the invention that depending on the stored in the safety cabinet hazardous substances, the air quantity control is varied.

In this context, the invention initially recommends a detection of the hazardous substances, typically in terms of quantity, vapor pressure and hazard potential. These parameters can, for example, manually via a control unit or as it were automatically using a Reading unit are transmitted to the control unit. In the last-mentioned case, the reading unit may, for example, read out a label, a barcode, a QR code or the like on or on a canister or a comparable container which contains the relevant hazardous substance.

Depending on the parameters given above, the control unit then determines an optimum value for the required amount of air supplied or discharged and thus specifies the hazardous substance-specific air quantity control. Finally, as in the case of time-dependent air control, the control unit varies the performance of the ventilation assembly. This can also be practically reduced to 0 or almost 0 in the course of the hazardous substance-specific air quantity control, specifically in the event that currently no hazardous substances are stored in the relevant safety cabinet.

Additionally or alternatively, with the help of the control unit, a status-specific air quantity control can be carried out. This status-specific air flow control takes into account and reflects the current state of the relevant safety cabinet. Within the scope of the invention, the status or state of the cabinet means barrier properties which typically require a change in the air quantity control or a variation of the supplied or discharged air quantity.

These include, for example, status messages such as "door open" or "door closed", ie those which indicate the opening or closing status of the cabinet door regularly connected to the cabinet body. The status messages indicated above can be detected by at least one door opening sensor and reported to the control unit. In this case, you will proceed in response to signals from the door opening sensor regularly so that an open cabinet door automatically to increase the supplied or discharged Air volume corresponds, whereas a closed cabinet door represents the normal state.

A comparable status message of the safety cabinet is the circumstance, for example, if any leaks are present inside the cabinet or vapors escape uncontrollably. Any leaks can be determined, for example, by means of a moisture sensor located on the bottom of the cabinet. The signals of the humidity sensor are transferred to the control unit, which increases, for example, the amount of air removed as a function of the amount of liquid formed inside the cabinet. In this case, too, a status-specific air quantity control takes place in such a way that, taking into account the signals of the humidity sensor, the control unit correspondingly increases the power of the ventilation arrangement in the example. In principle, the statically-specific air control described with the aid of the control unit can also take into account, for example, the vapors produced in the interior of the cabinet during a media delivery, as is the case in principle in the prior art WO 2012/150217 A1 already described.

The ventilation arrangement may be designed on the cabinet side and / or on the building side. In any case, the control unit acts on the cabinet-side and / or building-side ventilation arrangement. In the case of the cabinet-side ventilation arrangement, the invention typically operates with a fan or fan arranged on or in the cabinet body, which fan can be installed in the associated exhaust air line and / or supply air line. The latter variant of the building-side ventilation arrangement corresponds in contrast to the fact that the ventilation arrangement is removed and separate from the safety cabinet is available. For example, it may be the ventilation arrangement to a part of a building-side ventilation arrangement or air conditioning unit in the building. That is, the building side Ventilation arrangement is basically present and according to the invention additionally modified to the effect that their performance is varied, at least in terms of time-dependent air flow control in the supply air and / or exhaust duct of the relevant safety cabinet. Optionally, the performance of the ventilation arrangement in question can also be modified specifically for the specific substance and / or status, as has already been described above.

According to an advantageous embodiment, the control unit, the sensor and the ventilation arrangement communicate via a data bus. Such a data bus is available in the present case because, on the one hand, the number of required lines can be reduced compared with conventional cabling and, on the other hand, a selective change and, in particular, expansion of the bus arrangement by connecting, for example, additional safety cabinets and / or sensors is not difficult. The data transfer is usually bidirectional.

In addition, it has proven useful if the data bus is designed as a local area network and the data transmission takes place in the form of data frames, in particular according to the Ethernet standard. Such local networks or data networks typically designate wired or wirelessly communicating data networks in which the data exchange takes place in a localized area, for example, extends over a building. The transmission rates of up to 100 Mbit / s and more observed here are entirely sufficient to vary the amount of air supplied to or removed from the safety cabinet as described. Because such variations are usually due to the inertia of the changed in their performance ventilation arrangement anyway on time scales of seconds or even more.

It has proven useful when several safety cabinets are connected to the data bus. Because in this way, the invention takes into account the fact that typically in a laboratory or other equipped with the safety cabinet space not only a copy is available, but usually several safety cabinets are set up. In the context of the invention, these security cabinets can now be connected to one another via the data bus in terms of data technology, specifically via one or more higher-level control units. That is, a control unit, for example, three safety cabinets above the data collected all the sensors of these 3 safes and also provides for the corresponding time-dependent air flow control in the associated exhaust duct and / or supply air.

Each safety cabinet can be equipped with its own exhaust air duct or supply air duct. Mostly, however, the cables are grouped together. Then you will usually work with a common central ventilation arrangement, which is part of the building-side ventilation arrangement respectively coincides with this.

In addition, it is of course within the scope of the invention, when each safety cabinet is equipped with its own cabinet-side ventilation arrangement. In addition, each safety cabinet can also each have an associated control unit and be connected via this to the data bus. With the help of each individual control units, the separate cabinet-side ventilation arrangements can be acted upon separately. But it is also possible that each individual control units or one or more parent Control units act on the common central building-side ventilation arrangement.

The higher-level control units thus communicate with the common central ventilation arrangement and / or the respective individual cabinet-side ventilation arrangements. The same applies to each individual cabinet-side control units. The communication of the control units connected to the data bus is typically carried out via a master / slave ranking. That is, the plurality of control units connected to the data bus issue their setting commands for the individual separate cabinet-side ventilation arrangements or the common central ventilation arrangement in a hierarchical form. This hierarchical management of the shared resource access in the form of the common data bus ensures that the individual users share the data channel according to a predetermined pattern.

For example, it is conceivable that a control unit or higher-level control unit as a master subscriber can control the common central ventilation arrangement at any time via the data bus. That is, in this case, the master control unit takes over the time-dependent air control in conjunction with the common central and mostly building-side ventilation arrangement. The other control units are included in this case only if the master control unit interrogates the associated slave control units in the sense of a "polling".

Either way, the invention opens the possibility to operate a single security cabinet with associated exhaust duct or supply air and control unit and cabinet-side ventilation arrangement as insular solution so that the amount of air supplied to him or discharged from him amount of air is varied depending on the time or with the help of the control unit, the time-dependent air quantity control takes place.

In addition to this island solution but also overall concepts are conceivable that not only summarize several safes in, for example, a room, but even all safety cabinets in a building that may be distributed over several rooms. Each individual one of these safety cabinets can be separated from the others with regard to the amount of air supplied or discharged from it. For this one will usually resort to an associated cabinet-side ventilation arrangement. Likewise, it is conceivable that the total quantity of air supplied to or removed from the safety cabinets is changed together. In this case, a common central ventilation arrangement is used regularly. This can be part of the already existing building-side ventilation arrangement, for example, part of an air conditioning unit or generally the building services. Here are the main benefits.

• Fig. 1 einen Sicherheitsschrank perspektivisch und
• Fig. 2 mehrere an einen Datenbus angeschlossene Sicherheitsschränke, die mit der erfindungsgemäßen Vorrichtung ausgerüstet sind.

In the following the invention will be explained in more detail with reference to a drawing showing only the embodiment; show it:

• Fig. 1 a safety cabinet in perspective and
• Fig. 2 a plurality of safety cabinets connected to a data bus and equipped with the device according to the invention.

In the Fig. 1 is a safety cabinet or hazardous materials cabinet shown, which serves for the storage of only reproduced there chemicals 1. In order to accommodate the chemicals 1 inside the cabinet or the safety cabinet, are to a cabinet body 2 in the embodiment two hinged doors 3 posted. With the help of the swing doors 3, an access opening in the cabinet body 2 can be closed and opened. In principle, of course, you can also work with a single swing door 3, but this is not shown.

The swing doors 3 can be in the embodiment synchronously opened and closed by an operator with one hand (one-handed operation). In addition, a two-handed operation of the type is possible and is encompassed by the invention that the two swing doors 3 are operated separately from each other with two hands. Furthermore, an automatic door opening and door closing is covered by the invention. This is not shown.

As usual, the cabinet body 2 has side walls 2a and a top or top wall 2b, a bottom wall 2c and finally a rear wall 2d. The swing doors 3 are each connected to vertical axis 4 rotatably connected to the cabinet body 2. Both swing doors 3 are connected in the embodiment and not limiting to a common connecting element 5 and respective connecting elements 5. The connecting element 5 or the two connecting elements 5 undergo an arrangement in the region of the top wall 2b. The only connection element 5 in the exemplary embodiment operates via push rods 6 on the respectively connected swing door 3.

The top wall 2b of the cabinet body 2 is equipped in the embodiment with one or more openings to which in the illustration and not limiting an exhaust duct 7 is connected. In the exhaust duct 7, a sensor 8 is placed for air flow measurement. With the aid of the sensor 8, consequently, the amount of air discharged through the exhaust duct 7 from the interior of the cabinet body 2 is detected and converted into corresponding measurement signals become. The sensor 8 may be designed for this purpose as a flow sensor for measuring the volume flow. Also, a sensor 8, which detects a pressure difference on the input side and output side, is conceivable at this point.

In addition, it can still be seen in the exhaust duct 7 shown a ventilation arrangement 9, which in the embodiment of the Fig. 1 is designed cabinet side, that is part of the illustrated security cabinet and finds an arrangement in his vicinity or at him.

The ventilation arrangement 9, like the sensor 8, is connected to a control unit 10. For this purpose, a data bus 11 is realized in the embodiment as a whole. In addition to the sensor 8 for air flow measurement in the interior of the exhaust duct 7, an operating unit 12 is still provided, which is mounted in the embodiment outside of a cabinet door or swing door 3. Furthermore, one recognizes a humidity sensor 13. Both the operating unit 12 and the humidity sensor 13 also communicate with the control unit 10. This may again take place via the data bus 11.

With the aid of the operating unit 12, data and parameters can be transmitted to the control unit 10 via the chemicals 1 stored in the interior of the cabinet body 2. As already explained in the introduction, this can be the quantity of the respective chemical 1, its vapor pressure and possibly its potential danger. Depending on this, the control unit 10 determines an output value for a power with which the ventilation arrangement 9 is activated.

For example, the higher the vapor pressure of the respective chemical 1 at normal temperature, the greater will be the power to be set is. As a consequence thereof, the control unit 10 connected to the sensor 8 ensures that the ventilation arrangement 9 is subjected to the corresponding power and consequently an air quantity control is carried out in the exhaust air line 7; in the example described, it is specific to the fuel, that is to say as a function of the quantity and severity Internally stored hazardous substances or chemicals 1.

In addition to this uniform optional hazardous substance-specific air quantity control with the aid of the control unit 10, according to the invention, a mandatory time-dependent air volume control is carried out in the relevant exhaust air line 7. This time-dependent air quantity control is specified by a timer not expressly shown and located in the control unit 10. In fact, it is conceivable in this context and as already explained in the introduction that the control unit 10 controls the ventilation arrangement 9, for example, as a function of the time of day and / or on weekdays, so that overall the time-dependent air volume control is realized.

As a consequence thereof, the exhaust air discharged via the exhaust duct 7 from the safety cabinet is adjusted to a normal value of the delivered air quantity during normal working hours, for example, and lowered during the evening and night hours. In the same way, a weekday-dependent air volume control in the exhaust duct 7 can be realized.

In addition to the previously mentioned time-dependent air quantity control in the exhaust duct 7 and additionally the optional hazardous substance air quantity control in the respective exhaust duct 7, the invention additionally opens the possibility to perform a status-specific air flow control. This status-specific air quantity control takes into account the current state of the safety cabinet. In this context For example, data transmitted by the humidity sensor 13 to the control unit 10 is evaluated. Likewise data of a door opening sensor 14.

If, for example, the door opening sensor 14 notifies that one or both swing doors 3 are open in the exemplary embodiment, this is implemented in the control unit 10 in such a way that the performance of the ventilation arrangement 9 is increased, for example by the escape of chemicals generated in the interior of the cabinet body 2 1 largely prevent the access opening. Similarly, the performance of the ventilation assembly 9 via the control unit 10 may be increased in the event that the humidity sensor 13 at the bottom of the cabinet body 2 or on the bottom wall 2c registering liquid registers, for example, from a leakage of the chemicals 1 receiving canisters or container may result. In this case, too, the increased performance of the ventilation arrangement 9 as a consequence of the signal from the humidity sensor 13 takes account of the fact that the quantity of exhaust air conveyed through the exhaust duct 7 must be increased in order to prevent any danger to the health of the operating personnel in any case.

The operating unit 12 is equipped in the embodiment with a display unit 15. About this display unit 15, an operator from the outside and even with closed swing doors or closet doors 3 on the status of the safety cabinet, the funded amount of exhaust air, etc. are informed. Thus, the display unit 15 may also report a detected and determined by the humidity sensor 13 leakage. Likewise, a possibly not completely closed swing door or cabinet door 3, which is detected by means of the door opening sensor 14. That is, the display unit 15 generally serves as a status / warning indication.

The control unit 10 is in the example shown after Fig. 1 provided on the cabinet side. That is, the respective safety cabinet shown there is equipped with its own and associated control unit 10. In addition to this separate cabinet-side control unit 10, however, it is also possible to realize a so-called higher-level control unit 10, as shown in the diagram after Fig. 2 is shown. In this case, a control unit 10 is provided for three individual safety cabinets and, as it were, superior to them. In this case, the higher-level control unit 10 collects all the data of the sensors 8, 13, 14 assigned to the respective safety cabinet as well as the data of the operating unit 12.

Also with regard to the ventilation arrangement 9 different designs are conceivable and are included according to the invention. In fact, the embodiment according to the Fig. 1 a cabinet-side ventilation arrangement 9, ie such a ventilation arrangement 9, which is assigned to the respective safety cabinet directly and is located in his environment or directly on the cabinet. In contrast, the shows Fig. 2 a variant in which works with a building-side ventilation arrangement 9. This building-side ventilation arrangement 9 may be part of an already existing building technology, an air conditioning unit, etc. That is, in this case, the individual safety cabinets shown there are not separately equipped with their own Schrankkorpi 2 with its own cabinet-side ventilation arrangements 9, but the removal of the exhaust air via the respective exhaust ducts 7 solely and solely with the help of the common central and building-side ventilation arrangement. 9 Of course, this does not exclude that individual or all safety cabinets can not additionally be equipped with a cabinet-side ventilation arrangement 9. This is not shown.

As already explained and especially in the Fig. 2 to recognize the data bus 11 is provided to the control unit 10, the at least one sensor 8 and the ventilation assembly 9 to connect data technology together so that the aforementioned units 8, 9, 10 can communicate with each other. The data bus 11 can be wired or wirelessly realized, because this is designed as a whole as a local area network, so is limited by its extent typically on a building. Of course, mixed forms of the type are conceivable that individual sensors 8 and 13,14, for example, communicate wirelessly with the associated control unit 10, whereas the control unit 10 acts on the ventilation arrangement 9 via a bus line designed as a cable.

The data transmission via the data bus 11 takes place in the form of data frames, in particular according to the Ethernet standard. Here, in the embodiment of the Fig. 2 a total of three safety cabinets connected to the data bus 11. The bus character also offers the possibility to connect additional safety cabinets, if necessary. Of course, for example, in a building with multiple data buses 11 are worked. This is not shown.

As already explained, the control unit 10 can be designed as a higher-level control unit 10, thus evaluating signals from the sensors 8, 13, 14 as well as the signals from the control unit 12 from a plurality of safety cabinets. In addition, there is the additional or alternative possibility that each safety cabinet is equipped with a respective associated control unit 10, as the Fig. 1 represents. In a similar way, cabinet-side ventilation arrangements 9 can be realized, as described in the Fig. 1 are shown. Alternatively or additionally, building-side central ventilation arrangements 9 can be used, such as Fig. 2 shows.

The higher-level control units 10 can also with the common central ventilation arrangement 9 as shown in the Fig. 2 communicate as well as the possibility exists that in the Fig. 2 shown superordinated control unit 10 with the respective individual cabinet-side ventilation arrangements 9 according to the example case after Fig. 1 is connected by data technology.

If several elements or control units 10 as well as various sensors 8, 13, 14 and the control unit 12 at the same time want to use the data bus 11 or use this for data transmission, one will generally work with a master / slave ranking. That is, in particular for the control units 10. That is, when realizing one or more control units or higher-level control units 10, one of these control units 10 assumes the function of a master control unit 10. The other control units 10 act in contrast as slave control units 10. This is convenient especially in the event that only one (only) building-side ventilation arrangement 9 is realized, as the Fig. 2 shows.

In fact, in such a case, the master control unit 10 is used to control the performance of the central common building-side ventilation arrangement 9. Depending on the specifications of this master control unit 10, the power of the ventilation arrangement 9 is set and specified accordingly. With the amount of air generated in this way and discharged via the respective exhaust ducts 7 then all the other safety cabinets are (also) acted upon in the example case. In this context, it is of course fundamentally also conceivable that the master control unit 10 polls the individual other slave control units 10 in each case according to rotation and possible specifications for the central common building-side Ventilation arrangement 9 modified according to the query results accordingly.

In addition to the described control of the ventilation arrangement 9 or the plurality of ventilation arrangements 9, a control loop is usually realized. That is to say, the control unit 10 predefines the electrical power that activates the ventilation arrangement. Depending on the signals of the associated sensor 8 then this electrical power for the ventilation arrangement in the sense of a control can be modified.

Claims (10)

Method for controlling the amount of air supplied to and / or discharged from a safety cabinet, after which an exhaust air line (7) and / or supply air line is connected to a cabinet body (2), and then signals at least one in the exhaust air line (7) and / or the supply air line arranged sensor (8) are evaluated for air flow measurement, characterized in that by means of a sensor (8) connected to the control unit (10) a time-dependent air quantity control in the exhaust duct (7) and / or the air supply takes place. A method according to claim 1, characterized in that by means of the control unit (10) additionally a hazardous substance-specific air quantity control is performed. A method according to claim 1 or 2, characterized in that by means of the control unit (10) additionally a status-specific air quantity control takes place. Method according to one of claims 1 to 3, characterized in that the control unit (10) acts on a cabinet-side and / or building-side ventilation arrangement (9). Method according to one of claims 1 to 4, characterized in that the control unit (10), the sensor (8) and the ventilation arrangement (9) communicate with each other via a data bus (11). A method according to claim 5, characterized in that the data bus (11) is designed as a local network and the data transmission takes place in the form of data frames, in particular according to the Ethernet standard. A method according to claim 5 or 6, characterized in that a plurality of safes are connected to the data bus (11), via one or more higher-level control units (10) and / or via a respective cabinet-side control unit (10). Method according to one of claims 1 to 7, characterized in that the control unit (10) in each case to the cabinet associated separate cabinet-side ventilation arrangements (9) acted upon separately from each other. Method according to one of claims 1 to 8, characterized in that the respective control unit (10) communicates with a common central ventilation arrangement (9) and / or the respective individual cabinet-side ventilation arrangements (9). Device for controlling the amount of air supplied to and / or discharged from a safety cabinet, wherein an exhaust duct (7) and / or supply air duct is connected to a cabinet body (2), and wherein signals at least one in the exhaust duct (7) and / or the supply air duct arranged sensor (8) are evaluated for air flow measurement, characterized in that by means of a sensor (8) connected to the control unit (10) a time-dependent air quantity control in the exhaust duct (7) and / or air supply takes place.

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