Device and method for drying compressed gas

Abstract

Device for drying compressed gas, which device (1) is provided with an inlet (2) and outlet (3), and vessels (6a, 6b) with a regenerable drying agent and a valve system (7) connecting the inlet (2) and outlet (3) to the vessels (6a, 6b), wherein the device (1) is provided with a regeneration line (9a) for the supply of a regeneration gas and with a regeneration line ((99bb)) for the discharge of regeneration gas, wherein the regeneration lines (9a, 9b) can be connected to a blow-off opening (13), or an outlet (ID of a blower (12) for the supply of ambient air, characterised in that an additional vessel (15) with a heat storage material is incorporated into the regeneration line (9a), and that a line (17) is provided connecting the inlet (18) of the blower (12) to the first regeneration line (9a), wherein in this line (17) a first closable valve (19) is arranged and wherein the device 1 is provided with a second valve (20) in the generation line (9a).

Description

[0001] Device and method for drying compressed gas

[0002] The present invention relates to a device for drying compressed gas .

[0003] More specifically, the invention is intended to increase the efficiency of a device for drying compressed gas , to make such device less dependent on environmental parameters and more reliable .

[0004] Devices for drying compressed gas , such as those known from BE2021 / 5615 , are already known, which are provided with an inlet for compressed gas to be dried and an outlet for dried compressed gas , wherein the drying device comprises at least two vessels containing a regenerable drying agent and an adj ustable valve system consisting of a first valve block and a second valve block connecting said inlet and said outlet , respectively, to said vessels , wherein the adj ustable valve system is configured such that at least one vessel can dry compressed gas while the other vessel is regenerated and cooled, and that by controlling the valve system, the vessels can each in turn dry compressed gas .

[0005] By regenerable drying agent is meant here a drying agent or desiccant which can absorb moisture from a gas by adsorption and which, when saturated with moisture , can be dried by passing a so-called regeneration gas through it . This process is also called regeneration of the drying agent . The regeneration gas is typically a hot gas . Although the principle of adsorption is involved here , the invention is also applicable to the principle of absorption .

[0006] When a vessel is drying, it will absorb moisture from the compressed gas being dried, causing the drying agent to become saturated . This means that it can absorb little or no additional moisture .

[0007] This vessel is then regenerated, typically passing a hot gas , said regeneration gas , for example hot air , through it . This hot gas will extract moisture from the drying agent and regenerate it .

[0008] The vessel can then optionally be cooled first before using it again to dry compressed gas . After regeneration, the drying agent will have been heated up . By first cooling the drying agent in a vessel before using the vessel again to dry, the drying agent will be able to extract moisture much more efficiently .

[0009] In order to provide for the regeneration of a vessel , the device known from BE2021 / 5615 is further provided with a first regeneration line , provided with heating means for the supply of a regeneration gas to the vessel being regenerated, and with a second regeneration line for the discharge of saturated regeneration gas , wherein the first and second regeneration lines are each connected to a different valve block, wherein the first and second regeneration lines respectively can be connected to a blow-off opening or to an outlet of a blower, respectively, or the like for the supply of ambient air , or vice versa . Said blower will be able to supply ambient air which is heated by said heating means before being sent to the vessel being regenerated, via the second valve block .

[0010] After passing through the vessel being regenerated, the saturated regeneration air will leave the device via said second regeneration line and the blow-off opening .

[0011] This known device has the specific feature that an additional vessel containing a regenerable drying agent is incorporated into the first regeneration line between the blow-off opening or blower and said heating means .

[0012] An advantage is that , during regeneration of the relevant vessel being regenerated, the ambient air will pass through the additional vessel before being heated .

[0013] All ambient moisture will be extracted by the drying agent in the additional vessel , such that regeneration can take place using this completely dry ambient air . This will ensure a more efficient regeneration .

[0014] This regenerated vessel is then first cooled .

[0015] For this purpose , the first regeneration line is connected to the blow-off opening and the second regeneration line to said blower .

[0016] The blower will now send a refrigerant gas through the second regeneration line and then through the regenerated vessel , wherein the drying agent is cooled by means of the refrigerant gas .

[0017] This refrigerant gas will leave the device via the first regeneration line , the additional vessel and the blow-off opening .

[0018] This means that the heat from that regenerated vessel will be transported via the cooling gas to the additional vessel and the drying agent in the additional vessel will thereby regenerate .

[0019] A disadvantage of such devices is that a relatively large amount of heat from the heat , produced by the heating means ( to heat the regeneration gas ) , is lost during said cooling of the vessel , without being reused . Furthermore , the cooling is a so-called open-loop cooling, wherein the ambient air , after having passed once through the vessel being cooled, is blown off , in order to allow to loose the dissipated heat . Since ambient air is not dry air , this means that , during cooling , the drying agent becomes somewhat saturated by the moisture from the ambient air .

[0020] The present invention aims to provide a solution to at least one of said and other disadvantages .

[0021] The present invention relates to a device for drying compressed gas , wherein the device is provided with an inlet for compressed gas to be dried and an outlet for dried compressed gas , wherein the drying device comprises at least two vessels containing a regenerable drying agent and an adj ustable valve system consisting of a first valve block and a second valve block connecting said inlet and said outlet , respectively, to said vessels , wherein the adj ustable valve system is configured such that at least one vessel can dry compressed gas , while the other vessel is regenerated and cooled, and such that , by controlling the valve system, the vessels each in turn can dry compressed gas , wherein the device is further provided with a first regeneration line , provided with heating means for the supply of a regeneration gas to the vessel being regenerated and with a second regeneration line for the discharge of saturated regeneration gas , wherein the first and second regeneration lines each are connected to a different valve block, wherein the first and second regeneration lines , respectively, can be connected to a blow-off opening or to an outlet of a blower , respectively, or the like , for the supply of ambient air , or vice versa , characterised in that in the first regeneration line between the blow-off opening or blower and said heating means , an additional vessel is incorporated, or is heat-transf erably coupled to it , which contains a heat accumulation material , and that a line is provided which connects the inlet of the blower to a point of the first regeneration line , located between the blow-off opening or blower and said additional vessel , wherein, in this line , a first closable valve is arranged and wherein the device is provided with a second valve in the first generation line between said point and the blow-off opening or blower .

[0022] An advantage is that , when cooling the particular vessel that is being cooled, the heat from that regenerated vessel will be transported via the cooling gas to the additional vessel and the heat accumulation material in the additional vessel will heat up in the process .

[0023] In other words : the additional vessel will store heat , originally originating from said heating means , to heat up the regeneration gas . Up to 20% of heat can be recovered in this way .

[0024] In a subsequent cycle , when the vessel being regenerated is regenerated, the ambient air will pass through the additional vessel before being heated .

[0025] This will heat it up, which means that said heating equipment will not have to heat up as high , meaning that it can be dimensioned smaller .

[0026] Another advantage is that the line allows for so-called closed-loop cooling , wherein ambient air is circulated through the closed loop through the vessel being cooled and the additional vessel .

[0027] Because new ambient air is not constantly used, no more ambient moisture is constantly sent to the vessel being cooled .

[0028] In other words , no ambient air, and therefore moisture , is drawn in by the blower, such that there is no pre-loading of moisture in the vessel during the cooling process . The heat storage material in the additional vessel stores the heat from the vessel being cooled, such that the circulating ambient air cools down after passing through the vessel being cooled .

[0029] Due to the presence of the additional vessel with heat accumulation material , it is not necessary to blow off the heated ambient air after passing through the vessel that is being cooled to loose the heat .

[0030] Heat storage material here refers to a material with a high heat capacity .

[0031] In a practical embodiment , the additional vessel is incorporated into the first regeneration line and contains a solid heat storage material , such as , for example , basalt .

[0032] An advantage of basalt is that it has a very high volume heat capacity, and can be provided in granular form in the additional vessel such that air can flow through it easily .

[0033] Alternatively, the additional vessel contains a liquid heat storage material , such as , for example , oil , and the additional vessel is heat-transf erably connected to the first regeneration line by means of a liquid circuit with a heat exchanger, incorporated into the first regeneration line .

[0034] A liquid heat accumulation material can also be used, in which case the liquid heat accumulation material is circulated through a liquid circuit that comprises a heat exchanger through which it can flow and which is incorporated into the regeneration line to ensure heat transfer between the regeneration and cooling gas on the one hand , and the heat accumulation material on the other hand .

[0035] In a preferred embodiment , the additional vessel is provided with means to supply external heat to the heat storage material .

[0036] "External" here means heat , not originating from the device , for example in the form of steam.

[0037] These means allow heat that would otherwise be lost , to be recovered in the heat storage material .

[0038] It is not excluded that said means are also capable of removing heat from the additional vessel .

[0039] In a practical embodiment , the additional vessel is thermally insulated .

[0040] This thermal insulation can, for example , take the form of an insulating coating on the inside and / or outside of the additional vessel and / or a layer of insulating material with which the additional vessel is packed .

[0041] An advantage of this is that the heat which temporarily ends up in the additional vessel during the cooling phase, is stored as optimally as possible . In a preferred embodiment , the device is provided with a closable branch line for compressed, dried gas , running from the outlet to a point of the first regeneration line , located between the heating means and the additional vessel , wherein expansion means for the compressed, dried gas are provided in the branch line .

[0042] By "closable" is meant that , for example , means , such as a closable valve , are provided in the branch line that allow the branch line to be closed such that no gas can flow through it .

[0043] The branch line will allow part of the compressed, dried gas to be used as regeneration gas instead of ambient air .

[0044] After the regeneration with ambient air, as described above , a second regeneration phase can be started, wherein compressed dried gas is branched off , expanded and then sent via the heating means to the vessel being regenerated in order to regenerate the drying agent .

[0045] Due to the expansion and the heating means , this gas will be very hot and also very dry . This will improve the regeneration vastly and a very low dew point for the device and the dried compressed gas will be obtained .

[0046] The invention also relates to a method for drying compressed gas , wherein the method comprises the step of passing the compressed gas to be dried through a regenerable drying agent to extract moisture from the gas to be dried, wherein the drying agent is saturated with the extracted moisture , wherein the method further comprises the step of regenerating the saturated first drying agent by passing a regeneration gas through it , wherein dried and heated ambient air is used for the regeneration gas , characterised in that the method comprises the step of heating said ambient air by passing this ambient air through a heated heat storage material before passing it through the saturated drying agent to regenerate said drying agent , wherein the method comprises the step of cooling the regenerated drying agent by passing ambient air through it , wherein the ambient air is heated, and wherein the method further comprises the step of passing this heated ambient air through the heat storage material to heat the heat storage material .

[0047] The advantages of such a method are similar to those described above for the device .

[0048] Preferably, a device according to the invention is used to carry out this method .

[0049] With the insight to better demonstrate the characteristics of the invention, some preferred embodiments of a device and method for drying compressed gas according to the invention are described below, by way of example but without any limitation, with reference to the accompanying drawings , wherein :

[0050] Figure 1 schematically shows a device according to the invention for drying compressed gas ;

[0051] Figures 2 and 3 show variants of the layout of Figure 1 . The device 1 for drying a compressed gas , shown in Figure 1 , comprises an inlet 2 for compressed gas to be dried and an outlet 3 for dried compressed gas .

[0052] In the example of Figure 1 , the inlet 2 is connected to the outlet 4 of a compressor 5 .

[0053] The device 1 further comprises two vessels 6a, 6b , containing a regenerable drying agent .

[0054] It is not excluded for the invention that the device 1 contains more than two such vessels 6a , 6b .

[0055] The device 1 also contains an adj ustable valve system 7 , consisting of a first valve block 8a and a second valve block 8b .

[0056] The first valve block 8a will connect the vessels 6a, 6b to said inlet 2 for compressed gas to be dried, while the second valve block 8b will connect the vessels 6a , 6b to said outlet 3 for dried compressed gas .

[0057] Said valve blocks 8a, 8b are a system of different lines and valves which can be controlled such that at least one vessel 6a, 6b is always regenerated and subsequently cooled, while the other vessel 6a, 6b or the other vessels 6a , 6b dry the compressed gas , wherein, by controlling the valve system 7 , the vessels 6a , 6b will each in turn dry compressed gas . According to the invention, the device 1 further comprises a first regeneration line 9a for supplying a regeneration gas to the vessel 6a , 6b being regenerated and a second regeneration line 9b for discharging saturated regeneration gas .

[0058] The first and second regeneration lines 9a, 9b are each connected to a different valve block 8a, 8b .

[0059] In the example shown in Figure 1 , the first regeneration line 9a is connected to the second valve block 8b and the second regeneration line 9b is connected to the first valve block 8a , but this could also be the other way around .

[0060] Heating means 10 are incorporated into the first regeneration line 9a to heat the regeneration gas before it enters and flows through the vessel 6a, 6b being regenerated .

[0061] These heating means 10 , in this case , comprise an electric heater, but it is not excluded that these comprise a steam heater or a heat exchanger , incorporated into the first regeneration line 9a .

[0062] The heating means 10 may also comprise a heat exchanger which uses the compression heat of the compressor 5 to heat the regeneration gas .

[0063] Both the first and second regeneration lines 9a , 9b can be connected to an outlet 11 of a blower 12 or to a blow-off opening 13 . The blower 12 is used to be able to draw in ambient air. It is, of course, not excluded that, instead of a blower 12, other means are provided for drawing in ambient air.

[0064] Either the first regeneration line 9a is connected to an outlet 11 of a blower 12 and the second 9b to a blow-off opening 13 or vice versa, i.e. the second regeneration line 9b is connected to an outlet 11 of a blower 12 and the first regeneration line 9a to a blow-off opening 13.

[0065] Although it is possible to provide a blower 12 and a blowoff opening 13 for each regeneration line 9a, 9b and switching means to switch between them, in the example of Figure 1, it was chosen to provide the device 1 with a valve device in the form of a four-way valve 14 in order to achieve a more compact design.

[0066] However, such a compact valve device does not necessarily have to be equipped with a four-way valve 14.

[0067] The valve gear preferably comprises one or more of the following components:

[0068] - four-way valve (14) ;

[0069] - three-way valve;

[0070] - butterfly valve;

[0071] - on / off valve.

[0072] The valve device can consist of, for example, four separate butterfly valves, four separate on / off valves or two three- way valves . Via the four-way valve 14 , the first and second regeneration lines 9a, 9b can be connected to the outlet 11 of the blower 12 and to the blow-off opening 13 or vice versa, respectively .

[0073] For this purpose , one connection point of the four-way valve 14 is connected to the first regeneration line 9a, one connection point to the second regeneration line 9b, one connection point to the blow-off opening 13 and one connection point to the outlet 11 of the blower 12 .

[0074] By switching the four-way valve 14 , it can be selected which of the two regeneration lines 9a , 9b is connected to the outlet 11 of the blower 12 and which to the blow-off opening 13 .

[0075] Figure 1 shows the situation of a position of the four-way valve 14 wherein the first regeneration line 9a is connected to the blow-off opening 13 .

[0076] Here , the device 1 is such that , in this position of the four-way valve 14 , the ambient air, drawn in by the blower 12 , can enter the vessel 6b that is being cooled via the four-way valve 14 , the second regeneration line 9b and the first valve block 8a .

[0077] Of course , the valve system 7 is controlled appropriately to allow the correct flow path for the ambient air . When the four-way valve 14 is switched, the first regeneration line 9a will be connected to the outlet 11 of the blower 12 .

[0078] Here , the device 1 is such that , in this position of the four-way valve 14 , the ambient air, drawn in by the blower 12 , can enter the vessel 6b being regenerated via the fourway valve 14 , the first regeneration line 9a and the second valve block 8b .

[0079] Here , the valve system 7 is also controlled appropriately to allow the correct flow path for the ambient air .

[0080] According to the invention, an additional vessel 15 is incorporated into the first regeneration line 9a between the blow-off opening 13 or the blower 12 and said heating means 10 .

[0081] In this additional vessel 15 , a heat accumulation material is arranged . In this case , this material concerns basalt , in the form of granules .

[0082] In addition, the additional vessel 15 is in this case, but not necessarily, packed in an insulating material 16 to thermally insulate the additional vessel .

[0083] Alternatively, it is also possible to thermally insulate the additional vessel 15 by means of an insulating coating on the inside and / or on the outside of the additional vessel According to the invention, the device is also provided with a line 17 connecting the inlet 18 of the blower 12 to a point P of the first regeneration line 9a, located between the blow-off opening 13 of blower 12 and said additional vessel (15) .

[0084] A first closable valve 19 is provided in this line 17.

[0085] Furthermore, the device 1 is provided with a second valve 20 in the first regeneration line 9a between said point P and the blow-off opening 13 or blower 12. This valve 20 can also be located on the blow-off opening 13, i.e. the blow-off opening 13 is provided with the valve 20.

[0086] It is this line 17 that will be used to form a closed circuit when a vessel 6a, 6b is cooled.

[0087] The device 1 is, in this case, also provided with a first temperature sensor 21a at a location between the heating means 10 and the vessel 6a, 6b being regenerated, and in this case, but not necessarily, with a second temperature sensor 21b at a location in the second regeneration line 9b.

[0088] Said second valve 20 is, in this case, an adjustable valve, and is controlled by a control unit 22, based on the temperature, measured by the first temperature sensor (21a) and / or second temperature sensor (21b) .

[0089] The control unit 22 will also control the first closable valve 19. The operation of the compressed gas drying device 1 is very simple and as follows .

[0090] During operation of the device 1 , compressed gas to be dried will enter the drying vessel 6a via the inlet 2 and through appropriate control of the valve system 7 .

[0091] In the example of Figures 1 and 2 , the left-hand vessel 6a will dry compressed gas .

[0092] As it passes through this left-hand vessel 6a, the drying agent will extract moisture from the gas .

[0093] The dried compressed gas will leave the device 1 through the outlet 3 .

[0094] By appropriately controlling the valve system 7 , the correct flow path for the compressed gas to be dried is achieved .

[0095] The other , in this case right-hand, vessel 6b, which has already dried gas during a previous cycle or phase , contains moisture and is being regenerated in the meantime .

[0096] In this case , a regeneration cycle is used, which consists of heating ambient air and passing it through the relevant vessel 6b and then blowing it off .

[0097] To this end, the four-way valve 14 is positioned in the correct position . The blower 12 will draw in ambient air which will enter the additional vessel 15 via the four-way valve 14 .

[0098] Here , the ambient air will be heated by means of the heat , accumulated in a previous phase and then further heated by the heating means 10 , if necessary .

[0099] The heated ambient air will now be led via the second valve block 8b to the right-hand vessel 6b to regenerate the drying agent in this vessel 6b .

[0100] After passing through the vessel 6b, the drying agent in that vessel 6b will not only be dried but also heated .

[0101] The ambient air will then leave the device 1 via the first valve block 8a, the four-way valve 14 , and the blow-off opening 13 .

[0102] Now, the right-hand vessel 6b has been regenerated, that is to say, the moisture has been removed from the drying agent , and heated up .

[0103] In order to ensure that this vessel 6b can optimally dry compressed gas during a subsequent cycle or step , it is first cooled .

[0104] After all , cold drying agent can dry better than warm drying agent .

[0105] To this end, the four-way valve 14 is switched to the correct position, as shown in Figure 1 . The state or position of the valve system 7 is not changed, such that the left-hand vessel 6a can still dry compressed gas in the meantime .

[0106] By switching the four-way valve 14 , the ambient air, drawn in by the blower 12 , will now reach the vessel 6b via the first valve block 8a and remove the heat from this vessel 6b .

[0107] The now heated ambient air enters the additional vessel 15 via the second valve block 8b and the heater 10 .

[0108] The heated ambient air will now heat the additional vessel 15 , i . e . the heat extracted from the vessel 6b is stored in the heat storage material of the additional vessel 15 .

[0109] As a result of this process , the right-hand vessel 6b will be cooled and the heat accumulation material in the additional vessel 15 will be heated .

[0110] Due to the insulation 16 that is provided, all this heat will be optimally stored in the additional vessel 15 . It should be noted that this insulation 16 is not essential for the invention .

[0111] After the ambient air has released its heat into the additional vessel 15 , it will be led back to the inlet 18 of the blower 12 via the line 19 .

[0112] In other words , it will not be blown off , but recirculated . To enable this closed circuit , the control unit 22 will appropriately control the first closable valve 19 and the second valve 20 , in this case by opening the valve 19 and closing the valve 20 .

[0113] When the first temperature sensor 21a or the second temperature sensor 21b were to measure a temperature that is higher than can be tolerated by the blower 12 , the control unit 22 will close the closable valve 19 and open the second valve 20 . This results in the ambient air , after passing through the additional vessel 15 , being blown off via the blow-off opening 13 and the blower 12 will continuously draw in new ambient air to cool the vessel 6a .

[0114] At the end of this cooling step, the drying agent in the left-hand vessel 6a will be saturated and this vessel will be ready to be regenerated, while the right-hand vessel 6b is now ready to dry compressed gas .

[0115] By controlling or switching the valve system 7 , it will now be ensured that compressed gas to be dried ends up in the right-hand vessel 6b for drying .

[0116] Meanwhile, the left-hand vessel 6a will be regenerated in a similar manner as in the previous step .

[0117] Here , the four-way valve 14 will be set into the first position . The blower 12 will draw in ambient air which will end up in the additional vessel 15 .

[0118] Here , the ambient air will be heated by the heat , stored in the heat accumulation material .

[0119] As a result , dried and already preheated ambient air will enter the heating means 10 via the first regeneration line 9a .

[0120] Since the ambient air has already been preheated, the heating means 10 will have to be set lower, with the result that the maximum temperature the heating means 10 must deliver, will be lower .

[0121] Furthermore , the regeneration and subsequent cooling of this vessel 6a proceeds in the same way as described above for the right-hand vessel 6b .

[0122] After cooling of the left-hand vessel 6a, the right-hand vessel 6b will be saturated and the vessels can be exchanged again .

[0123] The entire cycle then repeats itself from the beginning .

[0124] Of course , it is not excluded that said control unit 22 is used to control said heating means 10 .

[0125] The control unit 22 can control the heating means 10 , based on the temperature sensors 21a and / or 21b . Although in the example shown and described, there are only two vessels 6a , 6b , it is not excluded that there are more than two vessels 6a, 6b, in which case at least one vessel 6a, 6b will always dry compressed gas .

[0126] For example , there may be six vessels 6a , 6b, of which three vessels 6a, 6b will dry compressed gas , two vessels 6a , 6b will be regenerated and one vessel 6a, 6b will be cooled .

[0127] Figure 2 shows an alternative embodiment .

[0128] In this case , the additional vessel 15 contains a liquid heat storage material , such as , for example , oil .

[0129] Also , it is not incorporated into the regeneration line 9a, but instead it is connected to it in a heat-transfer manner by means of a liquid circuit 23 .

[0130] In addition to the additional vessel 15 , the liquid circuit 23 also comprises a heat exchanger 24 which is incorporated into the first regeneration line 9a .

[0131] In addition, a pump 25 is also provided to pump the liquid heat accumulation material around in the liquid circuit in order to allow the ambient air flowing in the regeneration line 9a to extract or absorb heat from the heat accumulation material .

[0132] In the embodiment of Figure 3 , the difference with Figure 1 is the addition of a closable branch line 26 for compressed, dried gas , running from the outlet 3 to a point Q of the first regeneration line 9a, located between the heating means

[0133] 10 and the additional vessel 15 .

[0134] In this branch line 26 , in addition to a closable valve 28 , expansion means 27 for the compressed dried gas are provided .

[0135] By means of this branch line 26 , it will be possible to introduce a second regeneration phase , after the regeneration phase described above and before the cooling phase described above is started . The second regeneration phase preferably takes place at a higher temperature than the first regeneration phase .

[0136] In this second regeneration phase , dried compressed gas will be branched off at the outlet 3 and expanded by means of the expansion means 27 . This will already be accompanied by a heating of the gas .

[0137] Subsequently, the heating means 10 will further heat the expanded dried gas ; subsequently, it is sent to the vessel to be regenerated via the heating means to regenerate the drying agent .

[0138] Due to the expansion and the heating means 10 , this gas will be very hot and also very dry . This will improve the regeneration a lot and a very low dew point for the device 1 and the dried compressed gas will be obtained .

[0139] In all examples shown in Figures 1 and 3 , means 29 are provided in the additional vessel 15 to supply external heat to the heat accumulation material . This additional heat originates from outside the device 1 , and, in this way, can be recovered and usefully used during the regeneration of a vessel 6a, 6b .

[0140] Finally, it is also possible that for each of said examples , the heating means 10 have two temperature set points , with the lower of the two temperatures being applied first during the regeneration phase , for example during the first half of the regeneration phase , and subsequently the higher temperature , during the second half of the regeneration phase .

[0141] This has the advantage that the temperature of the drying agent in the vessel 6b that is regenerated will be higher after the regeneration . This will ensure that , when this vessel 6b is cooled, the heat storage material in the additional vessel 15 can store more heat .

[0142] The total consumption of the heating means 10 and the degree of regeneration of the drying agent achieved will be the same , whether regenerating at 1 average temperature or at 1 lower and 1 higher temperature , but in the latter case more heat can be recovered .

[0143] The present invention is by no means limited to the embodiments described by way of example and shown in the Figures , but a device and method for drying compressed gas according to the invention can be realised in all kinds of variants without departing from the scope of the invention .

Claims

Claims1.- Device for drying compressed gas, which device (1) is provided with an inlet (2) for compressed gas to be dried and an outlet (3) for dried compressed gas, wherein the device (1) comprises at least two vessels (6a, 6b) containing a regenerable drying agent and an adjustable valve system (7) consisting of a first valve block (8a) and a second valve block (8b) connecting said inlet (2) and said outlet (3) , respectively, to said vessels (6a, 6b) , wherein the adjustable valve system (7) is configured such that at least one vessel (6a, 6b) can dry compressed gas, while the other vessel (6a, 6b) is regenerated and cooled, and such that, by controlling the valve system (7) , the vessels (6a, 6b) each in turn can dry compressed gas, wherein the device (1) is further provided with a first regeneration line (9a) , provided with heating means (10) for the supply of a regeneration gas to the vessel (6a, 6b) being regenerated and with a second regeneration line (9b) for the discharge of saturated regeneration gas, wherein the first and second regeneration lines (9a, 9b) each are connected to a different valve block (8a, 8b) , wherein the first and second regeneration lines (9a, 9b) , respectively, can be connected to a blow-off opening (13) or to an outlet (11) of a blower (12) , respectively, or the like, for the supply of ambient air, or vice versa, characterised in that in the first regeneration line (9a) between the blow-off opening (13) or blower (12) and said heating means (10) , an additional vessel (15) is incorporated, or is heat-transf erably coupled to it, which contains a heat storage material, and that a line (17)is provided which connects the inlet (18) of the blower (12) to a point (P) of the first regeneration line (9a) , located between the blow-off opening (13) or blower (12) and said additional vessel (15) , wherein, in this line (17) , a first closable valve (19) is arranged and wherein the device (1) is provided with a second valve (20) in the first generation line (9a) between said point (P) and the blow-off opening (13) or blower (12) .2.- Device according to claim 1, characterised in that the additional vessel (15) is incorporated into the first regeneration line (9a) and contains a solid heat accumulation material, such as, for example, basalt.3.- Device according to claim 1, characterised in that the additional vessel (15) contains a liquid heat accumulation material, such as, for example, oil, and that the additional vessel (15) is connected in a heat-transferring manner to the first regeneration line (9a) by means of a liquid circuit (23) with a heat exchanger (24) incorporated into the first regeneration line (9a) .4.- Device according to any one of the preceding claims, characterised in that the additional vessel (15) is provided with means (29) for supplying external heat to the heat accumulation material .5.- Device according to any one of the preceding claims, characterised in that the device (1) is provided with a first temperature sensor (21a) at a location between the heating means (10) and the vessel (6a, 6b) being regenerated and / orwith a second temperature sensor (21b) at a location in the second regeneration line (9b) .6.- Device according to claim 5, characterised in that said second valve (20) is an adjustable valve, and that the device (1) is provided with a control unit (22) for controlling the first valve (19) and the second valve (20) which are controlled on the basis of the temperature, measured by the first temperature sensor (21a) and / or second temperature sensor ( 21b ) .7.- Device according to any one of the preceding claims, characterised in that the device is provided with a closable branch line (26) for compressed, dried gas, running from the outlet (3) to a point (Q) of the first regeneration line (9a) , located between the heating means (10) and the additional vessel (15) , wherein expansion means (27) for the compressed, dried gas are provided in the branch line (26) .8.- Device according to any one of the preceding claims, characterised in that the heating means (10) have two temperature set points .9.- Device according to any one of the preceding claims, characterised in that the additional vessel (15) is thermally insulated.10.- Device according to any one of the preceding claims, characterised in that it has a valve device that is connected to said regeneration lines (9a, 9b) and configured such that it can connect the first and second regeneration lines (9a,9b) respectively to the outlet ( 11 ) of a blower ( 12 ) or to the blow-off opening ( 13 ) respectively, or vice versa, wherein the valve device comprises one or more of the following :- four-way valve ( 14 ) ;- three-way valve ;- butterfly valve ;- on / off valve .11 . - Method for drying compressed gas , wherein the method comprises the step of passing the compressed gas to be dried through a regenerable drying agent to extract moisture from the gas to be dried, wherein the drying agent is saturated with the extracted moisture , wherein the method further comprises the step of regenerating the saturated first drying agent by passing a regeneration gas through it , wherein dried and heated ambient air is used for the regeneration gas , characterised in that the method comprises the step of heating said ambient air by passing this ambient air through a heated heat storage material before passing it through the saturated drying agent to regenerate said drying agent , wherein the method comprises the step of cooling the regenerated drying agent by passing ambient air through it , wherein the ambient air is heated, and wherein the method further comprises the step of passing this heated ambient air through the heat storage material to heat the heat storage material .12 . - Method according to claim 11 , characterised in that a device ( 1 ) according to any one of the preceding claims 1 to 10 is used to carry out the method .

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