Filtering unit for a compressor

Abstract

The invention relates to a filter unit (10) for a compressor, comprising a housing (12) with an inlet (14) and an outlet (28) for a gas to be compressed, a particle prefilter (16) arranged downstream of the inlet (14) in the flow direction of the gas to be compressed, an ultraviolet irradiation unit (22) arranged downstream of the particle prefilter (16) in the flow direction of the gas to be compressed and designed to emit ultraviolet light, and a pre-switching device (40) designed and arranged to drive the ultraviolet irradiation unit (22). In the flow, the filter unit (10) is designed such that the gas supplied at the inlet (14) and to be compressed first passes through the particle prefilter (16), is then irradiated by the ultraviolet irradiation unit (22) and finally the gas can be supplied through the outlet (28) to the compressor. The invention also relates to a compressor comprising such a filter unit (10) and to a method of compressing breathing air using such a compressor.

Description

Technical Field

[0001] The present invention relates to a filter unit for a compressor, a compressor equipped with such a filter unit, and a method for compressing and bottling breathing air using such a compressor. Background Technology

[0002] When gases, especially breathing air, are compressed and bottled, there are already strict regulations regarding quality and maximum permissible contamination, such as the breathing air standard EN 12021:2014-07, according to which all contaminants must be less than one-tenth of the national 8-hour exposure limit; however, recently it has also been desirable or necessary to inactivate any viruses that may be present in the gas to be compressed before compression and bottling. Therefore, it should be understood that, in the context of this specification, the term "gas" always includes gas mixtures as well.

[0003] Based on current understanding, due to the structure and size of the virus, this inactivation can only be achieved using heating, pressurization, appropriate chemicals, and ultraviolet irradiation.

[0004] When heating is used, the gas needs to remain at a temperature above 120°C for 8 minutes. Although such conditions can be created in the compressor's intake zone, the gas to be compressed must be cooled again in a complex manner because the maximum intake temperature that conventional compressors cannot exceed is approximately 45°C.

[0005] On the other hand, the compressor itself can sometimes exceed 200°C, but the gas residence time under these conditions is typically only a few seconds, so this method cannot reliably inactivate viruses. It should also be considered that heating an already pressurized container would result in a significant additional pressure increase, potentially damaging the container or necessitating its design for even higher pressures, leading to a substantial increase in cost.

[0006] Finally, raising the temperature before filling the container causes a significant drop in pressure within the container as the gas cools, thus preventing the storage of the intended amount of gas. Therefore, it is impossible to adequately heat the gas to be bottled in an efficient and cost-effective manner at any point during the compression and bottling process.

[0007] Similarly, viruses cannot be inactivated by pressurization or chemicals because, on the one hand, pressures exceeding 4,000 bar are required, which is not economically feasible, and on the other hand, many processes exclude the use of disinfectants, especially for the compression and bottling of breathing air. Summary of the Invention

[0008] Therefore, the object of the present invention is to provide a filter unit for a compressor that can reliably and efficiently inactivate viruses contained in the gas to be compressed.

[0009] For this purpose, a compressor filtration unit according to the present invention includes a housing having an inlet and an outlet for a gas to be compressed, a particulate pre-filter disposed downstream of the inlet in the flow direction of the gas to be compressed, an ultraviolet irradiation unit configured to emit ultraviolet light and disposed downstream of the particulate pre-filter in the flow direction of the gas to be compressed, and a ballast configured to control the ultraviolet irradiation unit. The filtration unit is designed such that the gas to be compressed, fed into the inlet, first passes through the particulate pre-filter, is then irradiated by the ultraviolet irradiation unit, and finally can be delivered to the compressor through the outlet.

[0010] Therefore, the inventors' contribution lies in their recognition that using the filter unit according to the invention, active viruses in the gas can be removed before the gas is actually compressed, wherein the particulate pre-filter protects the ultraviolet irradiation unit from contamination and prevents a decrease in its efficiency and inactivation rate.

[0011] The ballast is also responsible for providing electrical power to the irradiation unit, and can be configured, for example, to provide an increased current during the turn-on process and a substantially constant current thereafter.

[0012] Furthermore, the filter unit according to the invention is suitable for both mobile and stationary compressor systems because it is installed in the intake line in the atmosphere. This also makes the unit according to the invention particularly suitable as a retrofit solution, as it can operate completely independently and only requires itself to power the ballast and irradiation unit. Additionally, it should be noted that although this specification primarily relates to the inactivation of viruses in the gas to be compressed, the filter unit according to the invention can also be used effectively against bacteria, spores, etc.

[0013] In an advantageous embodiment, the housing of the filter unit according to the invention can be made, particularly internally, at least partially, and preferably entirely, of anodized aluminum in the region of the ultraviolet irradiation unit. For example, anodized aluminum has superior reflectivity in the relevant ultraviolet wavelength range compared to stainless steel, which improves irradiation efficiency, while the absorption of irradiation by stainless steel can lead to an undesirable increase in housing heat. In particular, the housing can be made, at least partially, of an aluminum tube commonly used in the manufacture of high-capacity air cylinders. This ensures a cost-effective supply of this critical component and allows the use of tubes, particularly those with product numbers 61089, 62333, and 60174.

[0014] Furthermore, the housing within the UV irradiation unit region can be elongated, particularly cylindrical, such as cylindrical. This not only creates a suitable receiving space for the typically elongated irradiation unit but also increases the residence time of the gas within the effective irradiation region, thus ensuring the efficiency of the filtration unit. Additionally, the cylindrical shape of the housing within the UV irradiation unit region ensures the generation of laminar airflow along the irradiation unit, where the gas is always guided to pass through at a clearly defined distance. Furthermore, it avoids undesirable flow within the housing that might be caused by undercuts, etc.

[0015] Another measure to improve the efficiency of the unit according to the invention may include further configuring the ballast to adapt the control of the ultraviolet irradiation unit to the ambient temperature and / or the temperature of the gas to be compressed, which can be input by the user using an input unit or detected by means of a suitably configured sensor unit. This improvement is based on the fact that the inactivation rate is generally temperature-dependent; therefore, the ultraviolet irradiation unit must be designed to be at least powerful enough to achieve the desired inactivation rate even in the least efficient temperature range. For example, at higher temperatures, its irradiation power can be reduced by the ballast. The input unit and / or sensor unit used can be any suitable known type of such unit and can be accordingly configured and operatively coupled to the ballast.

[0016] As a safety measure and to prevent the compression and / or bottling of insufficiently treated gas in the event of a malfunction or other problem with the ultraviolet irradiation unit, the filter unit according to the invention may further include a monitoring unit configured to monitor the proper operation of the ultraviolet irradiation unit. In particular, suitable methods may be considered for monitoring the electrical characteristics of the ultraviolet irradiation unit, such as interruptions in the power supply circuit, malfunctions of the irradiation unit during operation, short circuits or damage to the emitting electrodes, voltages below the minimum permissible power supply voltage, or voltages exceeding the maximum voltage applied to the irradiation unit. Furthermore, a sensor for ultraviolet irradiation may be provided within the housing, which outputs a corresponding signal when the irradiation intensity falls below a predetermined threshold.

[0017] One possibility for further processing incorrect operation of the ultraviolet irradiation unit detected by the monitoring unit is that the filtering unit according to the invention also includes a notification unit, which is operatively coupled to the monitoring unit and configured to output a notification upon detection of a deviation from the correct operation of the ultraviolet irradiation unit. Indicating devices such as displays or simply warning lights may be considered here, or alternatively or supplementarily, an audible signal unit may be considered. In addition to the notification unit, data may also be output from the monitoring unit to another device, such as the control unit of a corresponding compressor, which will be discussed further below.

[0018] Because conventional compressors generate considerable vibrations during operation that will eventually damage the UV irradiation unit, it is advantageous, particularly in embodiments according to the invention where the filter unit is in direct contact with the compressor, to secure the UV irradiation unit within the housing in a vibration-damping manner, especially by means of at least one spring clip, preferably made at least partially of a ceramic and / or metal plate material. Materials such as ceramic and metal plates are preferred alternatives to cheaper plastics because they offer greater resistance to UV radiation.

[0019] Alternatively or supplementarily, particularly in embodiments according to the invention where the filter unit is mounted on the housing of the associated compressor, the filter unit may include at least one support disposed on the outside of the housing and preferably includes at least one damping element for mechanical vibration, such as an elastomeric damping element, wherein the support preferably includes at least one permanent magnet to allow it to be easily fastened to a surface made of ferrous metal without tools. However, alternatively, other fastening means, such as screws or adhesive materials, may of course be provided.

[0020] While irradiation across the entire ultraviolet spectrum has an inactivating effect on viruses, bacteria, and the like, the ultraviolet irradiation unit of the filter unit according to the present invention can be specifically configured to emit ultraviolet light in the UVC range, preferably at a wavelength of about 254 nm. Lamps emitting light in this wavelength range are commercially available, and this radiation offers good performance in terms of absorption in various gases and, as mentioned, reflection on anodized aluminum oxide, without causing the unwanted generation of ozone from oxygen, which can occur even under short-wave radiation conditions.

[0021] Although particulate pre-filters can be of various suitable types in order to reliably prevent dirt particles from entering the housing of the filter unit according to the invention, it has been shown that particulate pre-filters of at least filter class F7 are particularly suitable for this purpose.

[0022] A further contribution to ensuring the intended operation of the filter unit according to the invention could be to provide a vacuum monitoring unit configured to provide notification of excessive pressure differential between the interior of the housing and the surrounding environment, and which in particular could be located in the area of ​​the particulate pre-filter. Commercial vacuum monitors (monitors for pressures below ambient pressure) could be considered here, which would issue a corresponding signal indicating that the particulate pre-filter is clogged with particles accumulated over its service life and must be replaced when such a pressure differential exceeds a predetermined threshold.

[0023] According to a second aspect, the present invention relates to a compressor, particularly a breathing air compressor and / or a multi-stage reciprocating compressor, comprising a compressor body having at least one compressor motor and a filter unit according to the invention. Multi-stage reciprocating compressors are known to those skilled in the art and typically include, in addition to multiple reciprocating stages connected in series, cooling, drying, and separation units for handling compressed gases.

[0024] In the example described above, where the filter unit includes a monitoring unit and the compressor also includes a control unit, the control unit can be operatively coupled to or integrated with the monitoring unit and can be configured to adjust the compressor's operation, such as shutting down the compressor or opening a flush valve, upon detecting a deviation from the correct operation of the UV irradiation unit. In this way, the compressor is prevented from being filled with insufficiently treated gas, where the use of the flush valve allows the compressor to compress the gas drawn in through the filter unit but simply vent it from the compressor into the environment instead of bottling it, and prevents at least one compressor motor from repeatedly switching on and off in the event that the UV irradiation unit is only temporarily malfunctioning.

[0025] As an alternative or supplement, the compressor may also include a timing unit configured to ensure the time interval between the start-up of the UV irradiation unit and the start-up of at least one compressor motor. On one hand, a fixed value for this delay can be considered, which experience has shown is necessary for the irradiation unit to achieve its intended performance; alternatively, an electrical or electronic circuit can be considered that is assigned to the irradiation unit and only issues a start signal for the compressor motor when the intended performance is achieved. In this case, starting at least one compressor motor can also be understood as closing the corresponding flushing valve. In either case, this measure ensures that bottling of the compressed gas only begins when the UV irradiation unit has reached its intended operating state (i.e., it has undergone a preheating phase).

[0026] Although the outlet of the filter unit can be directly connected to the air inlet of the compressor body via a flange, a suction hose can also be installed between the filter unit and the compressor body, attached to, and preferably sealed to, the outlet of the filter unit using an elastic material. This allows for flexible positioning of the filter unit; for example, the filter unit can be secured to the compressor housing using the permanent magnet mentioned above.

[0027] Furthermore, the compressor according to the invention may include a safety device configured, for example, based on a monitoring unit of the aforementioned filter unit, to ensure that the compressor can only operate when the filter unit is operational. However, it may be advantageous for the safety device to also include a means to exceptionally allow the compressor to operate even when the filter unit is not operational, for example, in situations where the availability of the compressor's basic functions far outweighs the disadvantage of the filter unit ceasing operation during a disaster. Such a means may include a push-button switch or a code input device.

[0028] Finally, the present invention relates to a method for compressing and bottling breathing air using a compressor according to the invention, wherein the breathing air to be compressed is drawn in through a filter unit, then compressed by at least one compressor motor, and finally bottled at a pressure, for example, between 90 bar and 550 bar. Attached Figure Description

[0029] Further features and advantages of the invention will become clearer from the following description of the embodiments taken in conjunction with the accompanying drawings. Specifically, in the drawings:

[0030] Figure 1 A schematic side view of the filtering unit according to the present invention is shown;

[0031] Figure 2 It shows Figure 1 The filter unit along Figure 1 A sectional view of section AA; and

[0032] Figure 3a and Figure 3b It shows Figure 2 A magnified, detailed view of two areas. Detailed Implementation

[0033] The filter units according to the present invention are respectively in Figure 1 and Figure 2 As shown in the figure, and generally indicated by reference numeral 10, the filter unit 10 includes a multi-part housing 12, which includes an inlet 14 for gas located on a first part 12a, which is located at the top in the figure and can optionally be connected to a suction hose. The various parts of the multi-part housing 12 described below are respectively and firmly connected to each other, for example by riveting, threading, welding, etc., wherein in some embodiments, the multiple parts of the housing 12 may also be formed integrally with each other.

[0034] The chamber in the first portion 12a of the housing 12 contains filter material that forms an annular particulate pre-filter 16, through which gas flowing in through inlet 14 passes before entering the actual interior of the housing 12. The filtration unit 10 includes a vacuum monitoring unit 18, also assigned to the first portion 12a of the housing 12, for indicating potential blockage of the particulate pre-filter 16. Since the first portion 12a of the housing 12 is closed at its top by a releasably clamping and sealing cap 12e, an openable passage to the interior of the housing 12 can be provided therein, through which the filter material of the particulate pre-filter 16 can be removed and replaced, for example, periodically.

[0035] The second part 12b of the housing 12 is located below the first part 12a, and it is in Figure 3a The enlarged detailed view again shows, and therein is a first fastening element 20a for the rod-shaped ultraviolet irradiation unit 22, which can be inserted and replaced by loosening and removing the second part 12b, which is screwed onto the third part 12c of the housing 12 described below by means of threads (not shown). The irradiation unit 22 can be designed, for example, as a fluorescent tube for ultraviolet light with a wavelength of about 254 nm, by means of which any viruses, bacteria, spores, etc. present in the gas flowing inside the housing can be inactivated or killed.

[0036] In the illustrated embodiment, the first fastening element 20a is formed of a spring clip, which holds the irradiation unit 22 in a vibration-damping manner, to which a socket 24 for supplying power to the irradiation unit 22 is detachably mounted from above. A threaded cable connection 26 is also provided on the outer side of the second portion 12b of the housing 12 to which a power cable for supplying power to the ultraviolet irradiation unit can be fastened, wherein an electrical connection (not shown in the figure) between the threaded cable connection 26 and the socket 24 is provided within the second portion 12b of the housing 12.

[0037] The irradiation unit 22 extends from the first fastening element 20a through the third portion 12c of the housing 12 to the fourth portion 12d, in which it is held in a similar manner by the second fastening element 20b, which also... Figure 3b The image is shown in a magnified, detailed view. Here, the third part 12c of the housing 12 is made of anodized aluminum because this material reflects ultraviolet light of the wavelength in question, thus improving the efficiency of the device and counteracting overheating. Other parts of the housing 12 may also be made of aluminum or other materials, such as stainless steel, because they are less exposed to radiation from the irradiation unit 22.

[0038] Finally, a flanged outlet 28 is attached to the lower side of the fourth portion 12d of the housing 12, to which a suction hose 30, for supplying irradiated gas to the compressor body (not shown here), is fastened in a configuration not shown in the figures. It should be noted that no additional passages to the interior of the housing 12 are provided in the areas of the third portion 12c and the fourth portion 12d, as well as the outlet 28. Therefore, no complex measures are required to seal the housing 12 on this side of the filter unit 10, where the gas has been irradiated and is thus ready for compression and final bottling, while reliably preventing severe contamination of the treated gas.

[0039] Furthermore, it should be noted that on the outer side of the housing 12, particularly in the region of its third part 12c, two brackets 34 are mounted by means of mounting clamps 32. Each bracket includes an elastomeric damping element 36 and a permanent magnet 38, and by means of them the filter device 10 can be mounted on a surface made of ferrous metal, such as the outer side of a compressor system (not shown). Together with the fastening elements 20a and 20b described above, the damping element 36 serves to isolate the filter device 10, particularly the ultraviolet irradiation unit 22, from vibrations and shocks generated during compressor operation.

[0040] Furthermore, the ballast 40, in the form of a switch box, is mounted on the housing 12 in a similar manner via two mounting clamps 32 and undertakes all control tasks required for the operation of the filter unit 10, particularly the ultraviolet irradiation unit, as well as power supply via an additional threaded cable connection 42 and a cable (not shown). The ballast 40 is powered from the power grid via the connection (not shown), allowing the filter unit 10 to operate autonomously. The ballast 40 can also be operatively coupled to additional electronic components, optionally provided and not shown herein, such as sensors for ambient temperature or the temperature of the gas drawn into the filter unit 10, a monitoring unit for the function of the ultraviolet irradiation unit, a notification unit for the user, and / or a control unit for the compressor body.

Claims

1. A compressor comprising a compressor body having at least one compressor motor and a filter unit (10), said filter unit (10) comprising: The housing (12) has an inlet (14) and an outlet (28) for the gas to be compressed. A particulate pre-filter (16) is disposed downstream of the inlet (14) in the direction of flow of the gas to be compressed; An ultraviolet irradiation unit (22) is disposed downstream of the particulate pre-filter (16) in the flow direction of the gas to be compressed and is configured to emit ultraviolet light; as well as A ballast (40) is constructed and configured to control the ultraviolet irradiation unit (22). The filter unit (10) is designed such that the gas to be compressed, introduced at the inlet (14), first passes through the particulate pre-filter (16), is then irradiated by the ultraviolet irradiation unit (22), and finally is sent to the compressor through the outlet (28). The compressor also includes a safety device configured to ensure that the compressor operates only when the filter unit is in operation, and the safety device also includes means to exceptionally allow the compressor to operate even when the filter unit is not in operation.

2. The compressor according to claim 1, wherein, The housing (12) is at least partially made of anodic aluminum oxide in the region of the ultraviolet irradiation unit (22).

3. The compressor according to claim 1 or 2, wherein, The housing (12) is elongated in the region of the ultraviolet irradiation unit (22).

4. The compressor according to claim 1 or 2, wherein, The ballast (40) is also configured to adapt the control of the ultraviolet irradiation unit (22) to the ambient temperature and / or the temperature of the gas to be compressed, which can be input by the user using the input unit or detected by the sensor unit.

5. The compressor according to claim 1 or 2, further comprising a monitoring unit configured to monitor the proper operation of the ultraviolet irradiation unit (22).

6. The compressor of claim 5, further comprising a notification unit operatively coupled to the monitoring unit and configured to output a notification upon detection of a deviation from the correct operation of the ultraviolet irradiation unit (22).

7. The compressor according to claim 1 or 2, wherein, The ultraviolet irradiation unit (22) is fastened inside the housing (12) in a vibration-damping manner.

8. The compressor according to claim 1 or 2, further comprising at least one bracket (34) disposed on the outside of the housing (12).

9. The compressor according to claim 1 or 2, wherein, The ultraviolet irradiation unit (22) is configured to emit ultraviolet light in the UVC range.

10. The compressor according to claim 1 or 2, wherein, The particulate pre-filter (16) is at least filter class F7.

11. The compressor according to claim 1 or 2, further comprising a vacuum monitoring unit (18) configured to provide notification of excessive pressure difference between the interior of the housing (12) and the surrounding environment.

12. The compressor according to claim 5, wherein, The compressor also includes a control unit that is operatively coupled to or integrated with the monitoring unit and is configured to adjust the operation of the compressor when a deviation from the correct operation of the ultraviolet irradiation unit (22) is detected.

13. The compressor according to claim 1 or 2, further comprising a timing unit configured to ensure a time interval between the start-up of the ultraviolet irradiation unit (22) and the start-up of the at least one compressor motor.

14. The compressor according to claim 12, wherein, A suction hose (30) is provided between the filter unit (10) and the compressor body, which is attached to the outlet (28) of the filter unit (10).

15. The compressor according to claim 1, wherein, The compressor is a breathing air compressor and / or a multi-stage piston compressor.

16. The compressor according to claim 2, wherein, The housing (12) is at least partially made of anodized aluminum in the region of the ultraviolet irradiation unit (22).

17. The compressor according to claim 2, wherein, The housing (12) is made entirely of anodized aluminum in the region of the ultraviolet irradiation unit (22).

18. The compressor according to claim 2, wherein, The housing (12) is made entirely of anodized aluminum in the region of the ultraviolet irradiation unit (22).

19. The compressor according to claim 2, wherein, The shell can be manufactured using a tubing.

20. The compressor according to claim 3, wherein, The housing (12) is cylindrical in the region of the ultraviolet irradiation unit (22).

21. The compressor according to claim 20, wherein, The housing (12) is cylindrical in the region of the ultraviolet irradiation unit (22).

22. The compressor according to claim 7, wherein, The ultraviolet irradiation unit (22) is secured within the housing (12) by means of at least one spring clip.

23. The compressor according to claim 22, wherein, The spring clip is at least partially made of ceramic and / or metal plate material.

24. The compressor according to claim 8, wherein, The support (34) includes at least one damping element (36) for mechanical vibration.

25. The compressor according to claim 24, wherein, The damping element (36) is an elastic damping element.

26. The compressor according to claim 8, wherein, The support (34) includes at least one permanent magnet (38).

27. The compressor according to claim 9, wherein, The wavelength of the ultraviolet light is 254 nm.

28. The compressor according to claim 11, wherein, The vacuum monitoring unit (18) can be positioned in the area of ​​the particulate pre-filter (16).

29. The compressor according to claim 12, wherein, The control unit is configured to shut down the compressor or open the flushing valve when a deviation from the correct operation of the ultraviolet irradiation unit (22) is detected.

30. The compressor according to claim 14, wherein, The suction hose (30) is sealed to the outlet (28) of the filter unit (10) by means of an elastic material.

31. A method for compressing breathing air using a compressor, wherein, The compressor is a compressor according to any one of claims 1 to 30, wherein breathing air to be compressed is drawn in through the filter unit (10), then compressed by at least one compressor motor, and finally bottled at a pressure between 90 bar and 550 bar.

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