EXPLOSION-PROOF ARRANGEMENT

Abstract

The invention relates to an explosion-proof arrangement (10) having an explosion-proof housing (11) which encloses a housing interior (13) and which is designed with the pressure-resistant encapsulation type of flame-proof protection. The housing interior (13) is subdivided into a first subregion (16) and a second subregion (17) by an intermediate wall (15) in such a way that the two subregions (16, 17) are explosion-proof relative to one another and consequently each subregion (16, 17) provides the pressure-resistant encapsulation type of flame-proof protection. At least one outer wall section (12a) of an outer wall (12) of the housing (11) is designed in a flame-proof and gas-permeable manner and allows gas exchange between the second subregion (17) and the surrounding area (14). A refrigeration machine (22) is arranged in the housing interior (13), wherein the evaporator (27) is located in the first subregion (16) and the condenser (24) is located in the second subregion (17). Heat from at least one electrical and/or electronic device (21) or another heat source in the first subregion (16) can therefore be dissipated into the second subregion (17) and from there to the surrounding area (14). This measure can prevent hotspots, which can ignite the explosion-hazard atmosphere in the surrounding area (14), from forming locally.

Claims

1. An explosion-proof arrangement, comprising: an explosion-proof housing, wherein the housing encloses a housing interior that is subdivided into a first compartment and a second compartment by an intermediate wall, wherein the intermediate wall forms a flameproof barrier between the first compartment and the second compartment and wherein at least one gas-permeable outer wall section of the housing adjoining the second compartment is configured to allow a flameproof gas exchange with an explosive atmosphere in an environment of the housing; at least one device forming a potential ignition source that is arranged in the first compartment that radiates heat during operation in the first compartment; and a chiller comprising an evaporator arranged in the first compartment and a condenser arranged in the second compartment.

2. The explosion-proof arrangement according to claim 1, wherein the housing comprises outer wall sections adjoining the first compartment that enclose the first compartment in a gas-tight manner with respect to the environment.

3. The explosion-proof arrangement according to claim 1, wherein the intermediate wall of the housing closes the first compartment in a gas-tight manner relative to the second compartment.

4. The explosion-proof arrangement according to claim 1, wherein the intermediate wall of housing is configured to allow a flameproof gas exchange between the two compartment.

5. The explosion-proof arrangement according to claim 1, wherein the chiller comprises a compressor that is arranged in the first compartment.

6. The explosion-proof arrangement according to claim 1, wherein the chiller comprises an expansion device that is arranged in the first compartment.

7. The Explosion-proof arrangement according to claim 1, wherein at least one fan is arranged in the first compartment and/or the second compartment.

8. The explosion-proof arrangement according to claim 1, wherein the gas-permeable outer wall section of housing adjoining the second compartment is covered by a protection cover arranged on an outside of housing.

9. The explosion-proof arrangement according to claim 8, wherein the protection cover comprises at least one opening, wherein the at least one opening is not arranged directly opposite the gas-permeable outer wall section in a straight direction.

10. The explosion-proof arrangement according to claim 1, wherein and inner volume of the first compartment is larger than an inner volume of the second compartment.

11. The explosion-proof arrangement according to claim 1, wherein a control device for control of the chiller is provided in order to control or feedback control a temperature in the first compartment and/or the second compartment.

12. The explosion-proof arrangement according to claim 11, wherein the intermediate wall of the housing closes the first compartment in a gas-tight manner relative to the second compartment.

13. The explosion-proof arrangement according to claim 12, wherein the intermediate wall of housing is configured to allow a flameproof gas exchange between the two compartments.

14. The explosion-proof arrangement according to claim 13, wherein the chiller comprises a compressor that is arranged in the first compartment.

15. The explosion-proof arrangement according to claim 14, wherein the chiller comprises an expansion device that is arranged in the first compartment.

16. The Explosion-proof arrangement according to claim 15, wherein at least one fan is arranged in the first compartment and/or the second compartment.

17. The explosion-proof arrangement according to claim 16, wherein the gas-permeable outer wall section of housing adjoining the second compartment is covered by a protection cover arranged on an outside of housing.

18. The explosion-proof arrangement according to claim 17, wherein the protection cover comprises at least one opening, wherein the at least one opening is not arranged directly opposite the gas-permeable outer wall section in a straight direction.

19. The explosion-proof arrangement according to claim 18, wherein and inner volume of the first compartment is larger than an inner volume of the second compartment.

20. The explosion-proof arrangement according to claim 19, wherein a control device for control of the chiller is provided in order to control or feedback control a temperature in the first compartment and/or the second compartment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Advantageous embodiments of the invention are derived from the dependent claims, the description and the drawings. In the following preferred embodiments of the invention are explained in detail with reference to the attached drawings. The drawings show:

[0025] FIG. 1 a schematic block-diagram-like illustration of an embodiment of an explosion-proof arrangement comprising an explosion-proof housing as well as a chiller,

[0026] FIGS. 2 and 3 a modified embodiment of the explosion-proof arrangement of FIG. 1 respectively and

[0027] FIGS. 4 and 5 a schematic perspective illustration of a gas-permeable flameproof structure respectively, as it can be used for a wall or a wall section in any embodiment of the explosion-proof arrangement.

DETAILED DESCRIPTION

[0028] FIG. 1 schematically shows an embodiment of an explosion-proof arrangement 10 that comprises an explosion-proof housing 11. The explosion-proof housing 11 has multiple and preferably six outer walls 12, of which only four outer walls are illustrated in the schematic sectional view in FIG. 1. For example, the housing 11 as a whole as a cuboid-shaped form. The housing 11 can also have other forms, such as cylindrical, prismatical or other free forms with planar and/or curved outer walls 12. The outer walls 12 enclose a housing interior 13 and separate it in a flameproof manner from an environment 14 having an explosive atmosphere surrounding the housing 11. The housing 11 is configured in the ignition protection category flameproof enclosure (Ex−d) according to one of the standards EN60079-1 or IEC 60079-1.

[0029] The housing interior 13 is separated by means of an intermediate wall 15 of the housing 11 in a first compartment 16 and a second compartment 17. The intermediate wall 15 is configured such that it separates the first compartment in a flameproof manner from the second compartment 17. The intermediate wall thus forms a flameproof barrier between the two compartments 16, 17. Both compartments 16, 17 are individually respectively configured in an explosion-proof manner in the ignition protection category flameproof enclosure (Ex−d).

[0030] A device that can be an ignition source for the explosive atmosphere in the environment 14, e.g. at least one electrical and/or electronic device 21 that is arranged in the first compartment 16 of the housing 11 or the housing interior 13 is part of the explosion-proof arrangement 10. The at least one electrical and/or electronic device 21 is housed in the first compartment 16 of the housing 11 in an explosion-proof manner. Potential electrical connections or conductors from the environment 14 into the first compartment 16 are guided through an outer wall 12 in an explosion-proof manner as known in the field of explosion protection per se. Such conductors or connections can be guided through the outer wall 12 in the first compartment 16 in an explosion-proof manner by forming a flameproof gap or by casting in a gas tight manner with the outer wall 12 or in another explosion-proof manner.

[0031] During operation the at least one electrical and/or electronic device 21 creates heat. The heat is radiated in the first compartment 16 and heats the outer walls 12 enclosing the first compartment 16. In addition, during operation of the at least one device 21 the temperature in the atmosphere of the first compartment 16 is increased, which can also be undesired for the operation of the at least one electrical and/or electronic device 21. For effectively dissipating heat out of the first compartment 16 the explosion-proof arrangement 10 comprises a chiller 22. The chiller 22 provides a closed fluid circuit of a cooling medium that takes different aggregate conditions in the fluid circuit. The cooling medium is compressed by means of a compressor 23 of the chiller 22 and is condensed and thus liquefied in a heat exchanger or condenser 24 following the compressor 23. During liquefaction of the cooling medium heat is radiated. The condenser 24 is arranged in the second compartment 17.

[0032] In the embodiment the condenser 24 is formed by a condenser tube coil 25 that is arranged in serpentine or meandering manner in the second compartment 17. The condenser tube coil 25 is guided through the intermediate wall 15 in a flameproof manner and is fluidically connected at one end with the compressor 23, whereas the other opposite end is fluidically connected with an expansion device 26 of the chiller 22.

[0033] The expansion device 26 can, for example, comprise an expansion valve and/or capillary tube. The expansion device 26 reduces the pressure of the cooling medium and the cooling medium is downstream of the expansion device 26 channeled to a heat exchanger or evaporator 27. In the evaporator 27 the cooling medium absorbs heat and evaporates at relatively low temperature. This process is also called evaporative cooling. Then the cooling medium from the evaporator 27 is again supplied to the compressor 23 and in doing so, a closed fluid circuit of the chiller 22 is achieved.

[0034] The evaporator 27 is arranged in the first compartment 16 in order to absorb heat that is radiated there from the at least one electrical and/or electronic device 21. In the embodiment also the compressor 23 and the expansion device 26 are arranged in the first compartment 16. In doing so, standard components or units can be used for the chiller. All of the components of the chiller 22 are arranged in an explosion-proof manner either in the first compartment 16 or in the second compartment 17.

[0035] Analog to the condenser 25 the evaporator 27 is formed by a serpentine-shaped or meander-shaped evaporator tube coil that can be placed in the first compartment 16 such that the heat radiation of the at least one electrical and/or electronic device 21 and the absorption by the cooling medium is optimized, particularly in that a section of the evaporator tube coil 28 is in spatial proximity to the at least one electrical and/or electronic device 21. In addition or as an alternative, at least sections of the at least one evaporator tube coil 28 can be placed along one or multiple outer walls 12—or at least sections thereof—that adjoin the first compartment 16. In doing so, a too high local heating of a respective outer wall 12 can be avoided.

[0036] For measurement of at least one temperature, at least one temperature sensor 30 can be arranged in the first compartment 16 and/or second compartment 17 that respectively creates a corresponding temperature signal T1 to T4 and is configured to transmit the respective temperature signal T1 to T4 to a control device 31. In the embodiment three temperature sensors 30 are arranged in the first compartment 16 that create a first temperature signal T1, a second temperature signal T2 and a third temperature signal T3 and transmit them to the control device 31. According to the example, an additional temperature sensor 30 is arranged in the second compartment 17 that creates a fourth temperature signal T4 and transmits it to the control device 31. The control device 31 can evaluate the temperature signals T1 to T4 and control the chiller 22, e.g. the compressor 23, by a first control signal S1.

[0037] In the embodiment illustrated in FIG. 1 it is shown in dashed lines that at least one fan can be arranged in the first compartment 16 and/or the second compartment 17 respectively in order to create an air circulation. For each provided fan 32 the control device 31 can create a respective control signal, e.g. a second control signal S2 for a fan 32 in the first compartment 16 and a third control signal S3 for a fan 32 arranged in the second compartment 17.

[0038] As schematically illustrated in FIGS. 1-3, at least an outer wall section of an outer wall 12 adjoining the second compartment 17 is configured as gas-permeable outer wall section 12a. In the embodiment illustrated in FIG. 1, one of the outer walls 12 adjoining the second compartment 17 is completely configured as gas-permeable outer wall, such that the gas-permeable outer wall section 12a forms the whole outer wall 12. The gas-permeable outer wall section 12a is configured in a flameproof manner, such that the second compartment 17 is explosion-proof with regard to the environment 14 and according to the example, complies with the requirements of a flameproof enclosure (Ex−d).

[0039] FIGS. 4 and 5 show highly schematically material structures respectively that fulfill provision of a flameproof gas exchange. For example, the gas-permeable outer wall section 12a can be formed by porous material 35 that is manufactured, for example, from a structure material of entangled fibers. The porous material 35 thereby comprises fibers entangled with one another, disorderly arranged that can have a diameter of about 70 μm to 130 μm. The pore size of the porous material 35 can have an amount of at least 80 μm and at most 250 μm. The porosity of the porous material 35 is preferably in a range of 60% to 80%.

[0040] In addition or as an alternative, the gas-permeable outer wall section 12a can be formed of a mesh or grid material 36 (FIG. 5). The mesh size has an amount of about at least 80 μm and at most 250 μm. Multiple layers 37 having different grid structures or grid bar orientations can be arranged on top of each other in order to allow a gas flow through the grid material 36 on one hand and to extinguish flames, sparks and hot gases on the other hand.

[0041] Also a combination of porous material 35 with grid material 36 is possible in order to form a gas-permeable outer wall section 12a.

[0042] A gas exchange between the second compartment 17 and the environment 14 is possible through the at least one gas-permeable outer wall section 12a. In doing so, heat radiated from the condenser 24 in the second compartment 17 can be dissipated outward in the environment 14. As already explained, for this a fan 32 can be arranged in the second compartment 17 in order to improve the gas exchange between the second compartment 17 and the environment 14.

[0043] As illustrated in FIGS. 1 and 2, the intermediate wall 15 can also comprise at least one gas-permeable intermediate wall section 15a that is configured in a flameproof manner. The flameproof gas-permeable intermediate wall section 15a can be configured analog to the gas-permeable outer wall section 12a and for this can comprise, for example, porous material 35 and/or grid material 36, which allows a gas exchange between the first compartment 16 and the second compartment 17 on one hand and however maintains the flameproof condition between the first compartment 16 and the second compartment 17 on the other hand.

[0044] In the embodiment illustrated in FIG. 1, the intermediate wall 15 is completely configured in a flameproof and gas-permeable manner analog to an outer wall 12 adjoining the second compartment 17. In modification thereto the intermediate wall 15 and/or an outer wall 12 can also be partly gas-permeable and can comprise an insert, for example, in order to form the gas-permeable outer wall section 12a and/or the gas-permeable intermediate wall section 15a, as schematically illustrated in FIG. 2.

[0045] In another alternative embodiment the intermediate wall 15 can also be substantially gas-impermeable, such that no purposed and intentional gas exchange occurs between the two compartments 16, 17 (FIG. 3).

[0046] The embodiments according to FIGS. 1-3 can also be combined with each other. For example, in all embodiments a complete outer wall adjoining the second compartment 17 can be realized in a flameproof and gas-permeable manner, as shown in FIG. 1. In the embodiment shown in FIG. 3 the intermediate wall 15 can be realized according to the embodiment of FIG. 1. Apart therefrom the embodiments according to FIGS. 1-3 are identical, such that reference can be made to the description of FIG. 1 above. For sake of clarity, the temperature sensors 30 and the control device 31 have been omitted in FIGS. 2 and 3.

[0047] In the embodiment shown in FIG. 3 having a substantially gas-impermeable intermediate wall 15 no fan 32 is provided in the first compartment 16 according to the example. In this embodiment at least one fan 32 can be sufficient in the second compartment 17 in order to support the air circulation between the second compartment 17 and the environment 14. Depending on the configuration of the chiller 22 and particularly the evaporator 27, in the embodiment according to FIG. 3 also a fan 32 can be provided in the first compartment 16, if an air circulation within the first compartment 16 is advantageous to support the heat transfer to the evaporator 27 and/or an improved temperature distribution in the first compartment 16 and the outer walls 12 of the housing 11 adjoining the first compartment 16.

[0048] As an option, the explosion-proof arrangement 10 can in addition comprise a protection cover 40 that is configured to cover the at least one flameproof gas-permeable outer wall section 12a and is arranged on the outside of housing 11. The protection cover 40 covers the at least one gas-permeable outer wall section 12a, particularly in order to protect it from splash water that is directly directed at the gas-permeable outer wall section 12a. The protection cover 40 comprises at least one and preferably multiple openings 41 in order to allow the gas exchange between the second compartment 17 and the environment 14. The at least one opening 41 is arranged such that it is not opposed to the gas-permeable outer wall section 12a in straight direction.

[0049] An effective heat transfer of the heat radiated by the at least one electrical and/or electronic device 21 out of the first compartment 16 in the second compartment 17 is provided by the explosion-proof arrangement 10. In the second compartment 17 an air circulation with the environment is allowed in order to emit warm air to the outside and to receive cooler air from the environment 14. All in all, a very uniform heat distribution is achieved. In doing so, hotter locations on the outer walls 12 of housing 11 are avoided that could serve as ignition sources for the explosive atmosphere in the environment 14. For control or feedback control of the chiller 22 the temperature can be determined at one or more locations, particularly also at least one temperature of the housing wall 12 of housing 11, particularly at a location at which the danger exists that the respective outer wall 12 of housing 11 is remarkably heated and could serve as ignition source.

[0050] The invention refers to an explosion-proof arrangement 10 comprising an explosion-proof housing 11 that encloses a housing interior 13 and that is configured in the ignition protection category flameproof enclosure. The housing interior 13 is divided in a first compartment 16 and a second compartment 17 by means of an intermediate wall 15 such that the two compartments 16, 17 are explosion-proof relative to each other and thus each compartment 16, 17 complies with the ignition protection category flameproof enclosure. At least one outer wall section 12a of an outer wall 12 of housing 11 is configured in a flameproof and gas-permeable manner and allows a gas exchange between the second compartment 17 and the environment 14. In the housing interior 13 a chiller 22 is arranged, wherein the evaporator 27 is located in the first compartment 16 and the condenser 24 is located in the second compartment 17. Heat of at least one electrical and/or electronic device 21 or another heat source in the first compartment 16 can thus be dissipated in the second compartment 17 and from there in the environment 14. Due to this measure, it can be effectively avoided that locally hot spots are created that could ignite the explosive atmosphere in the environment 14.

LIST OF REFERENCE SIGNS

[0051] 10 explosion-proof arrangement [0052] 11 housing [0053] 12 outer wall [0054] 12a gas-permeable outer wall section [0055] 13 housing interior [0056] 14 environment [0057] 15 intermediate wall [0058] 15a gas-permeable intermediate wall section [0059] 16 first compartment [0060] 17 second compartment [0061] 21 electrical and/or electronic device [0062] 22 chiller [0063] 23 compressor [0064] 24 condenser [0065] 25 condenser tube coil [0066] 26 expansion device [0067] 27 evaporator [0068] 28 evaporator tube coil [0069] 30 temperature sensor [0070] 31 control device [0071] 32 fan [0072] 35 porous material [0073] 36 grid material [0074] 37 layer [0075] 40 protection cover [0076] 41 opening [0077] S1 first control signal [0078] S2 second control signal [0079] S3 third control signal [0080] T1 first temperature signal [0081] T2 second temperature signal [0082] T3 third temperature signal [0083] T4 fourth temperature signal