Device for drying compressed gas and method for operating device for drying compressed gas

Abstract

Device for drying compressed gas, the device (1) being provided with an inlet (2) and an outlet (3) and a dryer (4) comprising a first and a second container (5a, 5b) and a controllable valve system (6) connecting said inlet (2) and outlet (3) to the containers (5a, 5b) wherein the controllable valve system (6) is such that the containers (5a, 5b) can each sequentially dry the compressed gas by controlling the valve system (6), wherein the device (1) is provided with a regeneration line (8), characterized in that the regeneration line (8) is connected to the collector block (9), and wherein a pressure controller (10) for controlling the pressure of the regeneration gas to a fixed desired pressure is combined wherein a plurality of collector lines (14) extend away from the collector block (9) towards each vessel (5a, 5b), wherein each of the collector lines (14) is provided with a constriction (16).

Description

Technical Field

[0001] This invention relates to an apparatus for drying compressed gas.

[0002] More specifically, the present invention is intended to dry compressed gases, such as compressed air, originating from a compressor. Background Technology

[0003] As is well known, compressed gases must be dried in most cases to remove water present in the gas in order to prevent damage to, for example, compressed gas consumers (such as pipes, valves, etc. in pneumatic tools or compressed air networks) from the presence of water.

[0004] For this purpose, an apparatus for drying compressed gas is known, which is provided with an inlet for the compressed gas to be dried and an outlet for the dried compressed gas.

[0005] This inlet is typically connected to the outlet of the compressor unit, and the outlet of the device for drying the compressed gas is typically connected to the consumer network.

[0006] A known apparatus includes a dryer comprising two containers containing a regenerable desiccant and a controllable valve system consisting of a first valve block and a second valve block, which respectively connect the inlet and the outlet to the containers.

[0007] The controllable valve system is configured to dry one container of compressed gas while another container is being regenerated, and the containers can be dried sequentially by controlling the valve system.

[0008] During the first stage of the drying cycle, compressed gas from the compressor is guided through one of the containers, such as container A, where it interacts with a desiccant. Moisture present in the compressed gas is absorbed by the desiccant, and the dried compressed gas exits container A.

[0009] Meanwhile, the regenerated gas will flow through another container, such as container B, to regenerate the desiccant in container B, or in other words, to remove moisture from the desiccant, which has dried the compressed gas during the previous stage of the drying cycle, thereby saturating the desiccant in container B with moisture.

[0010] After a certain amount of time, the desiccant in container A will be completely saturated, which means that the desiccant in container A can no longer absorb moisture.

[0011] At this moment, the next stage of the drying cycle will begin, in which the compressed gas to be dried is guided through container B, which now contains the regenerated desiccant, for drying via a switching valve system, while regenerated gas is guided through container A to regenerate the moisture-saturated desiccant.

[0012] To regenerate the container, i.e. to dry the moisture-saturated desiccant, regeneration gas is passed through the container.

[0013] For this purpose, known devices are equipped with a so-called regeneration line, which separates a portion of the dried compressed gas as regeneration gas and delivers it to the container being regenerated for the regeneration of the desiccant.

[0014] In known apparatuses, the regeneration line includes a line connecting an outlet located on two containers for this purpose, and the line guides a portion of the dried compressed gas from one container A, which is currently being dried, to another container B, which is currently being regenerated, and a constriction section is provided in the form of a nozzle therein.

[0015] The function of the nozzle is to ensure that the separated regeneration gas flows through container B at a specific flow rate.

[0016] The flow rate of regeneration gas through the container being regenerated is important because it affects the efficiency and speed of desiccant regeneration within the container.

[0017] Excessive flow rate will reduce efficiency and waste dried compressed gas, while insufficient flow rate will result in excessively long or incomplete regeneration time.

[0018] The characteristic of this nozzle is that, based on the pressure of the separated regeneration gas, a known specific flow rate will exit the nozzle.

[0019] Based on the properties of the compressed gas to be dried and the already dried compressed gas, and especially the pressure of the gas (also known as the operating pressure of the dryer), a suitable type and size of nozzle will be selected and arranged in the regeneration line so that the desired flow rate is achieved through the nozzle for this specific operating pressure.

[0020] The disadvantage is that the flow rate leaving the nozzle will change when the pressure of the dried compressed gas changes. The flow rate delivered by the nozzle depends on the pressure of the dried compressed gas, so an increase or decrease in this pressure will necessarily lead to an increase or decrease in the delivered flow rate.

[0021] This, of course, results in the regeneration gas being guided through the regenerating container at too high or too low a flow rate.

[0022] When the operating pressure of the compressor supplying the compressed gas to be dried changes, the pressure of the already dried compressed gas can be changed so that the device can be used for drying.

[0023] This primarily occurs in so-called mobile or "portable" applications, where operational pressure can vary daily.

[0024] To ensure that the desired flow rate of regenerated gas is still directed through the regenerated container under these conditions, various types and sizes of nozzles are available, which can be exchanged in the regeneration line based on the main operating pressure. In this way, by selecting a nozzle with the correct specifications, it is ensured that the desired flow rate of regenerated gas is always provided.

[0025] Of course, its disadvantage is that not only must all possible different nozzles be provided, but the device must also be shut down to allow for nozzle replacement in the regeneration line. Summary of the Invention

[0026] The present invention aims to provide a solution to at least one of the aforementioned and other disadvantages.

[0027] This invention relates to an apparatus for drying compressed gas, the apparatus having an inlet for compressed gas to be dried and an outlet for dried compressed gas. The apparatus includes at least one dryer, comprising at least a first container and a second container, and a controllable valve system. The first and second containers contain a regenerable desiccant. The controllable valve system includes a first valve block and a second valve block, which respectively connect the inlet and the outlet to the containers. The controllable valve system is configured such that at least one container dries the compressed gas while at least another container is being regenerated, and the containers can sequentially dry the compressed gas by controlling the valve system. The apparatus includes a regeneration line configured to separate a portion of dried compressed gas as regeneration gas and deliver it to at least one container being regenerated for regeneration of the at least one container being regenerated. The regeneration line is characterized by being connected to a collector block, wherein a pressure controller is incorporated into the regeneration line for controlling the pressure of the separated regeneration gas downstream of the pressure controller to a fixed desired pressure, wherein multiple collector lines exit the collector block, wherein each of the collector lines extends toward an inlet provided for this purpose in each container, and wherein a constriction is provided in each of the collector lines to obtain a desired flow rate of the separated regeneration gas.

[0028] The pressure controller controls the pressure of the separated regenerated gas downstream of the pressure controller to a fixed specific pressure, which is independent of the operating pressure of the device, i.e., the pressure of the dried compressed gas.

[0029] This means that even if the operating pressure of the device changes, the pressure of the regeneration gas downstream of the pressure controller will always have the same value.

[0030] Therefore, the regeneration gas in the collector block always has the same pressure, and thus the same pressure in the collector line.

[0031] One advantage is that the flow rate of regenerated gas passing through the contraction section will always be the same.

[0032] In other words, when the operating pressure changes, the same flow rate of regenerated gas will continue to flow through the container being regenerated, so that the regeneration of this container will always be carried out as efficiently as possible, without losing too much compressed dry gas due to insufficient regeneration of the regenerated gas or desiccant.

[0033] An additional advantage is that nozzle replacement is no longer required, and the constriction section, which can be in nozzle form, no longer needs to be replaced according to the main operating pressure. Therefore, it is no longer necessary to shut down the device.

[0034] The collector block enables the connection of regeneration lines to collector lines; the collector block is a collection block distributed to various "tap points," i.e., collector lines. The collector block can be implemented in various ways, as will be further explained in the description.

[0035] Furthermore, it is possible to have more than two containers in the dryer. In this case, the valve system will be expanded or modified so that one container is always drying while another is regenerating. The other containers can be dried or regenerated, or, if necessary, cooled after regeneration and before drying again.

[0036] Preferably, the pressure controller is bridged by a bypass line, incorporating a pressure equalization valve.

[0037] The purpose of a pressure equalization valve is to restore the pressure in the regenerating container to the operating pressure after regeneration.

[0038] At the start of regeneration, the container is at operating pressure, which is equal to the pressure of the compressed gas to be dried.

[0039] To initiate regeneration, first reduce the pressure in this container to or slightly above atmospheric pressure, and then pass the regeneration gas through the container.

[0040] After regeneration, the container will begin drying again. This means that the compressed gas to be dried passes through the container. The pressure difference between the gas pressure in the newly regenerated container and the pressure of the compressed gas to be dried can cause impact and damage to the container and / or the desiccant.

[0041] Therefore, it is recommended to increase the pressure of the gas in the container before starting the drying process again.

[0042] By opening the pressure equalization valve, the pressure controller is bypassed, and the separated regeneration gas will eventually flow directly into the collector block and collector line, and thus into the container, without reducing the pressure.

[0043] In a practical embodiment, a second check valve is provided in each of the collector lines between the collector block and the constriction section, which allows gas to flow only from the collector block to the container.

[0044] This has the following advantages: when the corresponding compressed gas container is drying, no compressed gas can flow through the collector line or leak into the collector block, while when the container is regenerated, regeneration gas can flow into the container.

[0045] In this embodiment, each collector pipe is equipped with a second check valve.

[0046] In an alternative embodiment, the collector block is divided into sub-collector blocks, each sub-collector block being connected to a regeneration pipeline, wherein the number of sub-collector blocks is set as many as the number of containers in one or more dryers, wherein each container or all corresponding containers of the dryer is connected to one of the sub-collector blocks.

[0047] In other words, if two containers are placed in the dryer, two sub-collector blocks will be provided; if three containers are present, three sub-collector blocks will be placed in the device.

[0048] The corresponding containers refer to those that are always in the same stage of the drying cycle, meaning they are always drying and regenerating simultaneously. This implies that if the drying cycle also includes a cooling stage, the containers connected to a specific sub-collector block are always either completely drying the compressed gas, completely regenerating, or completely cooling.

[0049] In this case, it is preferable to have a third check valve in the regeneration line, between the pressure controller and each of the sub-collector blocks, which allows gas to flow to only one of the sub-collector blocks.

[0050] These third check valves will ensure that no compressed gas flows or leaks through the collector line and collector block when the corresponding compressed gas container is drying, while regeneration gas can flow into the container when it is being regenerated.

[0051] In other words, the third check valve performs the same function as the second check valve, but in this embodiment, the total number of third check valves will be equal to or less than the number of second check valves in the previous embodiment. In this embodiment, the number of check valves is equal to the number of sub-collector blocks, while in the previous embodiment, the number of check valves was equal to the total number of containers.

[0052] In the case of an apparatus that includes multiple dryers, this will greatly reduce the number of check valves required.

[0053] In one practical embodiment, the device is provided with a minimum pressure valve connected to the outlet, and a regeneration line is connected to the outlet of the device, so that the dried compressed gas is separated as regeneration gas at the outlet.

[0054] The minimum pressure valve will ensure that if the pressure in the container becomes too low, the compressed air network connected to the outlet of the device will not allow any compressed air to be delivered to the device.

[0055] The setting of this minimum pressure valve allows the use of a regeneration line to divert dried compressed gas at the outlet of the unit, for example, slightly upstream of the minimum pressure valve.

[0056] A minimum pressure valve will not always be present (or may be required), for example, in cases where a minimum pressure valve is provided on a compressor or compressor unit connected to the unit inlet.

[0057] In this variant embodiment of the device, where the device does not have a minimum pressure valve at the outlet, a dryer is provided with a connecting line between the first and second containers, and two separate fourth check valves are provided in the connecting line, which only allow gas flow from the containers, wherein the regeneration line is connected to the point in the connecting line between the two check valves.

[0058] In other words, in this case, the regeneration gas is diverted from the container rather than at the outlet of the unit to prevent gas from the compressed air network from being used as regeneration gas when the operating pressure of the unit is too low.

[0059] Furthermore, the present invention relates to a method for operating an apparatus for drying compressed gas, wherein the method includes the following steps:

[0060] -Dry the compressed gas in a first container containing a first amount of renewable desiccant;

[0061] -A portion of the compressed gas that has been dried in the first container is separated as regeneration gas;

[0062] - The second container containing a second amount of regenerable desiccant is regenerated using the separated regenerable gas.

[0063] The characteristic feature is that the pressure of the regenerated gas is controlled to a fixed desired pressure to obtain a desired flow rate of the regenerated gas flowing into the second container.

[0064] Clearly, this method has the same and / or similar advantages as the above-described embodiments of the apparatus for drying compressed gas according to the present invention. Attached Figure Description

[0065] To better illustrate the features of the invention, some preferred embodiments of the apparatus for drying compressed gas according to the invention and the method of operating the apparatus for drying compressed gas according to the invention are described below by way of example and not in any way limiting, with reference to the accompanying drawings, wherein:

[0066] Figure 1 A first embodiment of the device according to the invention is shown schematically;

[0067] Figure 2 A second embodiment of the device according to the invention is shown;

[0068] Figure 3 It shows Figure 1 Variations;

[0069] Figure 4 Show Figure 2 A variant of . Detailed Implementation

[0070] Figure 1 An apparatus 1 for drying compressed gas according to the present invention is shown schematically.

[0071] The device 1 mainly includes an inlet 2 for the compressed gas to be dried, an outlet 3 for the already dried compressed gas, and a dryer 4.

[0072] In this case, more than one dryer 4 is set up, that is, five dryers 4.

[0073] Obviously, the present invention is not limited thereto, and any number of dryers 4 are possible.

[0074] Dryer 4 is connected in parallel between inlet 2 and outlet 3 of device 1, which means that each dryer 4 is directly connected to inlet 2 and outlet 3.

[0075] Each dryer 4 includes at least a first container 5a and a second container 5b.

[0076] Furthermore, the number of containers 5a and 5b is not limiting for the present invention, and in the example shown, each dryer 4 has exactly two containers 5a and 5b, but there may also be three, four, five or more containers 5a and 5b.

[0077] Each container 5a, 5b contains or is filled with a regenerated desiccant or moisture-proofing agent.

[0078] The dryer 4 is equipped with a controllable valve system 6, which includes a first valve block 7a and a second valve block 7b.

[0079] In the example shown, the first valve block 7a and the second valve block 7b for each dryer 4 are separate components or parts of the device 1, but this does not preclude the integration of all first valve blocks 7a into a common first valve block 7a and / or all second valve blocks 7b into a common second valve block 7b.

[0080] The first valve block 7a connects containers 5a and 5b of the dryer 4 to the inlet 2, while the second valve block 7b connects containers 5a and 5b to the outlet 3.

[0081] Each valve block 7a, 7b is a collection or combination of pipelines and valves, such as solenoid valves, 3 / 2 pneumatic valves, check valves, controllable valves, butterfly valves, which allow the various containers 5a, 5b of the dryer 4 to be connected to the inlet 2 and the outlet 3 at the appropriate time.

[0082] In fact, the controllable valve system 6 is configured such that one container 5a dries compressed gas, meaning that compressed gas can flow from inlet 2 through container 5a to outlet 3, while another container 5b is being regenerated, meaning that regenerated gas passes through the other container 5b.

[0083] By appropriately controlling or actuating valve system 6, containers 5a and 5b will each sequentially dry the compressed gas, thereby achieving a cyclic process. This drying process comprises several stages, wherein, for example, in a first stage, one container 5a will dry the compressed gas while the other container 5b will regenerate, and in subsequent stages, container 5a will regenerate while container 5b will dry. These two stages are repeated repeatedly during the drying process. This will be explained in more detail below.

[0084] The device 1 is also provided with a regeneration line 8. This regeneration line 8 separates a portion of the compressed and dried gas as regeneration gas and directs it to the container 5b being regenerated for the regeneration of this container 5b.

[0085] This regeneration line 8 is connected to the collector block 9.

[0086] Pressure controller 10 is incorporated in regeneration line 8 to control the pressure of the separated regeneration gas downstream of pressure controller 10 to a fixed desired pressure.

[0087] This pressure controller 10 can take various forms and may include a pressure reducing valve or a pressure control valve with electronic or mechanical control or a pressure controller equipped with a control valve.

[0088] In this case, but not necessarily, the pressure controller 10 is bridged to the collector block 9 via a bypass line 11, in which a pressure equalization valve 12 is incorporated.

[0089] In this case, but not necessarily, a first check valve 13 is incorporated in the regeneration line 8 between the pressure controller 10 and the collector block 9. This first check valve 13 is oriented such that it only allows gas to flow from the pressure controller 10 to the collector block 9.

[0090] According to the invention, the device 1 is further provided with a plurality of collection lines 14 extending from the collector block 9 to each container 5a, 5b, for which the containers 5a, 5b are provided with an inlet or connector 15 for one of these collector lines 14.

[0091] The number of collector lines 14 is equal to the total number of containers 5a and 5b; in Figure 1 In this case, there are ten collector pipelines 14.

[0092] According to the invention, a constriction section 16 is provided in each of these collector lines 14 to obtain the desired flow rate of the separated regeneration gas flowing to the containers 5a, 5b via the collector lines 14.

[0093] The constriction 16 in each of these collector lines 14 is located near containers 5a, 5b.

[0094] The constriction section 16 can be constructed in various ways: for example, as a nozzle or as an orifice plate. However, any component or device that can convert a specific pressure into a specific fixed flow rate is suitable for use as the constriction section 16.

[0095] Furthermore, in this embodiment, but not essential to the present invention, a second check valve 17 is provided in each collector line of collector line 14, between collector block 9 and contraction section 16, which only allows gas to flow from collector block 9 to containers 5a, 5b.

[0096] Furthermore, in this embodiment, but not essential to the present invention, a minimum pressure valve 18 is provided connected to outlet 3, and the regeneration line 8 is connected to outlet 3 of device 1, such that the dried compressed gas is separated from outlet 3 as regeneration gas.

[0097] Furthermore, in the example shown, a dew point sensor 19 is installed at outlet 3 to measure the dew point of the dried compressed gas leaving outlet 3.

[0098] Finally, in this case, but not necessarily required by the invention, the first valve block 7a is provided with purge valves 20a, 20b to purge regeneration gas after passing through the regenerating container 5b and / or purge compressed gas contained in the regenerating container 5b before regeneration begins.

[0099] More specifically, in this case, two purge valves 20a and 20b are provided, namely a first purge valve 20a and a second purge valve 20b, wherein the first purge valve 20a is used to purge compressed gas from container 5b before regeneration begins, and wherein both purge valves 20a and 20b are used to purge regeneration gas.

[0100] The operation of device 1 is very simple and is as follows.

[0101] Compressed gas to be dried, originating from a compressor or compressor unit, enters the device 1 through inlet 2.

[0102] The gas is guided to container 5a of dryer 4 via the first valve block 7a, where dryer 4 dries the compressed gas.

[0103] Compressed gas passes through desiccant container 5a, where the desiccant absorbs moisture present in the compressed gas.

[0104] The dried compressed gas then passes through the second valve block 7b to reach the outlet 3, where the dried compressed gas leaves the device 1 and is transferred to the compressed air network.

[0105] The other container 5b, which contains a moist desiccant, has already dried the gas during the previous cycle and is being regenerated at the same time.

[0106] For this purpose, the first valve block 7a and the second valve block 7b are properly connected.

[0107] First, the vent valve 20a will be opened to release the pressure from these containers 5b.

[0108] Subsequently, the dry compressed gas separated via regeneration line 8 and having an operating pressure equal to, for example, 12 bar will be depressurized by pressure controller 10 to a fixed desired pressure of, for example, 5 bar.

[0109] The regenerated gas enters the collector block 9 through the first check valve 13 at a pressure of 5 bar, and is then transferred to the container 5b to be regenerated via the collector line 14.

[0110] Since these containers 5b are under low pressure, regenerated gas can flow into these containers 5b through the second check valve 17.

[0111] Because the container 5a currently being dried is at operating pressure, the regeneration gas cannot pass through the second check valve 17 of these containers 5a.

[0112] Obviously, these second check valves 17 can be replaced by controllable or switchable valves that switch at the appropriate time to achieve the same function.

[0113] When the regenerated gas flows through the second check valve 17, the regenerated gas will be guided through the contraction section 16.

[0114] This ensures that the desired and appropriate flow rate of regenerated gas is directed through container 5b.

[0115] As the regenerating gas passes through these containers 5b, it extracts moisture from the saturated desiccant to regenerate it.

[0116] After passing through, the moist regenerated gas is now guided via the first valve block 7a to the purge valves 20a and 20b, both of which are now open.

[0117] Once regeneration is complete and the desiccant is fully regenerated and thus dried, container 5b will first be restored to operating pressure before drying again.

[0118] Therefore, after first closing the two vent valves 20a and 20b, the pressure equalization valve 12 is opened to bypass the pressure controller 10.

[0119] The compressed and dried gas separated by regeneration line 8 will now enter collector block 9 via bypass line 11 without experiencing a pressure drop, and from there via collector line 14 into container 5b until the container is pressurized.

[0120] The presence of the first check valve 13 prevents compressed dry gas from flowing back to the pressure controller 10.

[0121] Then, the next stage of the drying cycle can begin.

[0122] The next stage will begin based on the measurement of the dew point sensor 19 at outlet 3: when the dew point of the dried compressed gas reaches the threshold, which means that the desiccant in the container 5a of the dried compressed gas is saturated, the next stage will begin.

[0123] When the measured dew point is below the threshold, the subsequent stages will not begin. This means that containers 5a and 5b will not be replaced, and container 5b will now enter a standby phase, during which no further regeneration will be performed, while container 5a, which is drying the gas, will continue drying the compressed gas until the dew point of the dried compressed gas reaches the threshold.

[0124] During the subsequent stage, the first valve block 7a and the second valve block 7b are used to switch containers 5a and 5b, such that the compressed gas to be dried is directed to container 5b, which now contains dried desiccant after regeneration, and that regenerated gas is directed through container 5a, which now contains saturated desiccant after drying the compressed gas. The operation in this subsequent stage is as described above for the first stage, except that only the functions of containers 5a and 5b are switched.

[0125] exist Figure 2 The image shows a second embodiment of the device 1 according to the present invention, which is related to... Figure 1 The apparatus is very similar to that in this case, collector block 9 is divided into sub-collector blocks 9a and 9b, each of which is connected to regeneration line 8.

[0126] There are as many sub-collector blocks 9a, 9b as containers 5a, 5b in dryer 4. In this case, each dryer 4 has two containers 5a, 5b, and therefore also two sub-collector blocks 9a, 9b.

[0127] These sub-collector blocks 9a and 9b are each directly connected to the regeneration pipeline 8.

[0128] Each container 5a, 5b of the dryer 4 is connected to one of the sub-collector blocks 9a, 9b, wherein each container 5a, 5b of the dryer 4 is connected to the other sub-collector block 9a, 9b.

[0129] The corresponding containers 5a and 5b of different dryers 4 are connected to the same sub-collector blocks 9a and 9b.

[0130] The corresponding containers 5a and 5b refer to containers 5a and 5b that are always in the same stage of the drying cycle, that is, they are always drying and regenerating simultaneously. This means that containers 5a and 5b connected to specific sub-collector blocks 9a and 9b are always fully drying the compressed gas, fully regenerating, or fully cooling (if the drying cycle also includes a cooling stage).

[0131] Furthermore, in this case, but not necessary for the present invention, a third check valve 21 is provided in the regeneration line 8 between the pressure controller 10 and each sub-collector block 9a, 9b, which only allows gas to flow to the sub-collector blocks 9a, 9b.

[0132] More specifically, in this case, the third check valve 21 is positioned between the first check valve 13, which is located after the pressure controller 10, and each of the sub-connector blocks 9a, 9b.

[0133] In this embodiment, the second check valve 17 is not present in the collector line 14.

[0134] Otherwise, device 1 and Figure 1 The devices are the same.

[0135] Therefore, the operations are very similar.

[0136] When the compressed gas is dried in container 5a during the first stage of the drying process, the sub-collector block 9a connected to these containers 5a will now be under operating pressure.

[0137] The sub-collector block 9b connected to the regenerating container 5b is at a pressure of, for example, 5 bar, or the pressure controller 10 reduces the separated regeneration gas from the operating pressure to a lower pressure.

[0138] The separated compressed gas is guided to the sub-collector block 9b via regeneration line 8, pressure controller 10, and third check valve 21.

[0139] Because the pressure in sub-collector block 9a is higher than the pressure of the regeneration gas downstream of pressure controller 10, no regeneration gas will enter this sub-collector block 9a, and no dried compressed gas will flow from sub-collector block 9a to regeneration line 8 and another sub-collector block 9b.

[0140] In other words, the regenerated gas only enters the container 5b that needs regeneration. Even when the pressure equalization valve 12 is opened to repressurize the container 5b, the regenerated gas will only enter the sub-collector block 9b and thus the container 5b due to the action of the third check valve 21.

[0141] In addition, operation and Figure 1 The operation is the same as in the embodiments described above.

[0142] Figure 3 It shows Figure 1 A variation of device 1, wherein, in this case, there is no minimum pressure valve 18 at outlet 3.

[0143] Furthermore, the regeneration line 8 will not be connected to the outlet 3 of device 1, such as Figure 1 and Figure 2 The situation in the middle.

[0144] Conversely, a dryer 4 is provided with a connecting line 22 between the first container 5a and the second container 5b, and the connecting line 22 is provided with two separate fourth check valves 23, which only allow gas flow from containers 5a and 5b, wherein the regeneration line 8 is connected to point P in the connecting line 22 between the two check valves 23.

[0145] In addition, this embodiment is similar to Figure 1 The embodiments are the same as those in the example.

[0146] Therefore, the operation is very similar, except that in this case, the compressed gas will not be separated at outlet 3, but will be separated from connecting line 22.

[0147] Such an embodiment can be used when there is indeed no minimum pressure valve 18 at outlet 3, for example, because it is undesirable or impossible, or because the minimum pressure valve 18 already exists elsewhere in the system.

[0148] To prevent the regeneration line 8 from drawing compressed gas from the consumer network connected to the outlet 3 when the pressure in device 1 is too low, the regeneration line 8 is connected to the connection line 22 provided for this purpose.

[0149] Figure 4 It shows Figure 2 A variation of device 1, wherein, in this case, there is no minimum pressure valve 18 at the outlet.

[0150] Furthermore, the regeneration line 8 will not be connected to the outlet 3 of the device, such as Figure 1 and Figure 2 The situation in the middle.

[0151] Conversely, a dryer 4 is provided with a connecting pipe 22 between the first container 5a and the second container 5b, as... Figure 3 In this configuration, two fourth check valves 23 are provided that allow gas to flow only from containers 5a and 5b, with the regeneration line 8 connected to point P in the connecting line 22 between the two check valves 23.

[0152] In other respects, this embodiment is similar to Figure 2 The embodiments are the same as those in the example.

[0153] Therefore, the operation is very similar, except in this case, such as Figure 3 In this process, the compressed gas will not be separated at outlet 3, but will be separated from connecting line 22. The rest of the operation is as follows: Figure 2 The explanation.

[0154] For all four embodiments, what is the same is the method of controlling or operating device 1, which involves drying compressed gas in a first container 5a containing a regenerable desiccant, and separating a portion of the compressed gas dried by the first container and using it as regeneration gas to regenerate the regenerable desiccant in a second container 5b, wherein the pressure of the regeneration gas is controlled to a fixed desired pressure each time to obtain a desired flow rate of the regeneration gas to the second container 5b.

[0155] The present invention is by no means limited to the embodiments described by way of example and shown in the accompanying drawings, but the apparatus for drying compressed gas according to the invention can be implemented in various shapes and sizes without departing from the scope of the invention as defined in the claims.

Claims

1. An apparatus for drying compressed gas, the apparatus (1) comprising an inlet (2) for compressed gas to be dried and an outlet (3) for dried compressed gas, wherein, The device (1) is provided with at least one dryer (4), which includes at least a first container (5a) and a second container (5b) and a controllable valve system (6). The first container (5a) and the second container (5b) contain a regenerable desiccant. The controllable valve system (6) includes a first valve block (7a) and a second valve block (7b), which respectively connect the inlet (2) and the outlet (3) to the first container (5a) and the second container (5b). The controllable valve system (6) is configured such that at least one container (5a) of the first container (5a) and the second container (5b) dries compressed gas while at least another container (5b) of the first container (5a) and the second container (5b) is being regenerated. By controlling the controllable valve system (6), the first container (5a) and the second container (5b) can each sequentially dry compressed gas. The device (1) is provided with a regeneration line (8) configured to separate a portion of the dried compressed gas as regeneration gas and deliver the regeneration gas to at least one container (5b) being regenerated for regeneration of the at least one container (5b) being regenerated. The device is characterized in that the regeneration line (8) is connected to a collector block (9), wherein a pressure controller (10) is incorporated in the regeneration line (8) for controlling the pressure of the separated regeneration gas downstream of the pressure controller (10) to a fixed desired pressure. A plurality of collector lines (14) exit the collector block (9), wherein each of the collector lines (14) extends toward an inlet (15) for this purpose, the inlet (15) being provided in each of the first container (5a) and the second container (5b). A constriction section (16) is provided in the collector lines (14) to obtain a desired flow rate of the separated regeneration gas.

2. The apparatus according to claim 1, characterized in that, The pressure controller (10) is bridged by a bypass line (11), in which a pressure equalization valve (12) is incorporated.

3. The apparatus according to claim 1 or 2, characterized in that, A first check valve (13) is incorporated in the regeneration line (8) between the pressure controller (10) and the collector block (9), the first check valve allowing gas to flow from the pressure controller (10) to the collector block (9).

4. The apparatus according to claim 1 or 2, characterized in that, The device (1) is provided with a plurality of dryers (4), which are connected in parallel between the inlet (2) for the compressed gas to be dried and the outlet (3) for the already dried compressed gas.

5. The apparatus according to claim 1 or 2, characterized in that, In each of the collector lines (14), a second check valve (17) is provided between the collector block (9) and the contraction section (16), the second check valve allowing gas to flow from the collector block (9) to the first container (5a) and the second container (5b).

6. The apparatus according to claim 1 or 2, characterized in that, The collector block (9) is divided into sub-collector blocks (9a, 9b), each sub-collector block being connected to the regeneration line (8), wherein the sub-collector blocks (9a, 9b) are configured to be as numerous as the containers (5a, 5b) in the one or more dryers (4), wherein each container or all corresponding first containers (5a) and second containers (5b) of the dryer (4) is connected to one of the sub-collector blocks (9a, 9b).

7. The apparatus according to claim 6, characterized in that, A third check valve (21) is provided in the regeneration line (8) between the pressure controller (10) and each of the sub-collector blocks (9a, 9b), the third check valve allowing gas to flow to only one of the sub-collector blocks (9a, 9b).

8. The apparatus according to claim 1 or 2, characterized in that, The device (1) is provided with a minimum pressure valve (18) connected to the outlet (3), and the regeneration line (8) is connected to the outlet (3) of the device (1), such that the dried compressed gas is separated at the outlet (3) as regeneration gas.

9. The apparatus according to claim 1 or 2, characterized in that, The device (1) has no minimum pressure valve (18) at the outlet (3), and a dryer (4) has a connecting line (22) between the first container (5a) and the second container (5b), in which two fourth check valves (23) are provided, which only allow gas to flow from the first container (5a) and the second container (5b), wherein the regeneration line (8) is connected to a point (P) in the connecting line (22) between the two fourth check valves (23).

10. The apparatus according to claim 1 or 2, characterized in that, The contraction section (16) is implemented as a nozzle or an orifice plate.

11. The apparatus according to claim 1 or 2, characterized in that, The pressure controller (10) includes a pressure reducing valve or a pressure control valve or a pressure control valve with electronic or mechanical control or a pressure controller with a control valve.

12. The apparatus according to claim 1 or 2, characterized in that, The first valve block (7a) is provided with a purge valve (20a, 20b) to purge the regenerated gas after it passes through the container (5b) being regenerated, and / or purge the compressed gas contained in the container (5b) to be regenerated before regeneration begins.

13. A method of operating an apparatus for drying compressed gas, wherein, The method includes the following steps: - The compressed gas is dried in a first container (5a) containing a first amount of regenerable desiccant; -A portion of the compressed gas dried in the first container (5a) is separated as regeneration gas; -The second container (5b) containing a second amount of regenerable desiccant is regenerated using the separated regeneration gas. The characteristic feature is that the pressure of the regenerated gas is controlled to a fixed desired pressure to obtain a desired flow rate of the regenerated gas flowing into the second container (5b).

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