DE885589C - Method for drying gas compressed in a compressor by means of an internal combustion engine drive and device for carrying out the method - Google Patents

Description

Method for drying in a compressor by means of an internal combustion engine drive Compressed gas and equipment for carrying out the process Compressed gas, especially air, often contains a certain amount of moisture, which in many Cases with. The further use of this compressed gas is disruptive. It is known such Compressed gas from. its moisture content. get rid of it by using a moisture-binding agent Means is brought into contact. This means must be in one to this end Pressure-tight container be included.,. Which is flowed through by the compressed gas. When the agent has reached the limit of its absorption capacity, it must counteract a fresh remedy can be exchanged. There are also means known which by strong warming returned to the usable state (regenerated) will. can. Such an agent is, for example, silicon gel.

The invention relates to the drying of compressed gas by means of one of these. moisture-binding and heat-regenerable agent that, Enclosed in a pressure-tight container (hereinafter referred to as the dry matter container) is. According to the invention is in the drying of such compressed gas in a was compressed by an internal combustion engine driven compressor, alternately once the compressed gas (the useful gas) is passed through the inside of the container, which remains without external heat input, and the other time hot exhaust gas the focal: Kraftmaschri; ne to the heat effect on the outside = soap brought the container; at the same time the container interior can with the Connect outside air; thus the vapors forming inside the container can pull off to the outside.

The evacuation of vapors from inside the container during regeneration the contents of the container can still: be particularly promoted by this. that during the heat exposure of the exhaust gas to your container through its interior heated-dried gas (purging gas) is passed, the- the inside of the container, takes the vapors formed with it to the outside, i.e. flushes them away. It becomes useful: this Purge gas taken from the gas flow conveyed by the compressor; its amount just needs to be a small fraction of this gas flow.

The means for carrying out this process can be of various types be designed .. The simplest 'arrangement is when a desiccant container is provided, which is switched on in -the compressor pressure line and removed from it can be so that it is flowed through by the useful gas while it is switched on, and after its removal from the compressor pressure line into the exhaust line the internal combustion engine can be used so that it is outside of the exhaust gases is flowed around and that the vapors formed inside Zn to the outside can kick. So that the compressor continues during the regeneration process can work and deliver dry useful gas is appropriate a; second desiccant container intended; Of these two containers, the one is used for gas drying in the Compressor pressure line switched on, the other to regenerate its contents inserted into the exhaust pipe. In general, that is necessary for regeneration Time is essentially shorter than the period of time during which a container is used for gas dehumidification is usable; the container subjected to the regeneration process can therefore after completion can be removed from the exhaust line and allowed to cool again during regeneration the other tank is still built into the compressor pressure line, so that then, if .this latter container has to be replaced, the former ohine further can take its place. It is then only effective when expanding the a container from the exhaust pipe and also be in the exchange of the other, the container lying in the compressor pressure line against: the aforementioned a short one Business interruption required.

One also wants to avoid these short-term interruptions and d1 The need to change the container can be saved, which is quite the case, especially in the case of larger systems laboriously design, the arrangement can be made as follows: The exhaust pipe will be in three. Branch lines divided; two of these branches included. ever a built-in desiccant container, and instead of: exhaust gas can also be flowed through by fresh air. For the compressed gas, the purge gas, the Exhaust gas upd the fresh air switching elements are provided in such a way that by each of the two containers alternately useful gas (for drying the same) and flushing gas (for Expelling the vapors when regenerating the container contents) flow. can and. that in each case the container switched to regeneration first (to heat its Content) of exhaust gas and afterwards (to cool down) fresh air flows around it will.

The invention also relates to measures for the operation the switching elements of such a. To make setup as simple as possible.

Further details of the invention emerge from the following Description of several furnishing examples.

In the drawing, Fig. I shows a schematic representation of the overall compression system; Fig. 2 shows in longitudinal section the installation of a desiccant container in an exhaust line; Fig.3 shows an exhaust line divided into three branch lines, in which two of the branch lines each contain a desiccant container; Fig. 3a shows a modification of the device according to Fig. 3; Fig.q. shows a schematic circuit diagram to Fig. 3 with jointly adjustable switching elements; Fig. 5 shows a schematic diagram an arrangement in which the adjustments of all switching elements by means of a single actuator can be brought about.

Corresponding parts of different figures are labeled the same.

The gas digestion system according to Fig. I has a compressor i, which is driven by an internal combustion engine 2. That compressed by the compressor Gas (the useful gas) flows through a pressure line 3 to an aftercooler q., From there to a liquid separator 5, in that the q in the cooler. excreted drip Liquid collects, further to a filter 6, the dust and 4g1. holds back, then through a container containing a moisture-binding substance; through a filter 8, which holds back dust formed from this substance, and through an adjoining line 9 to the point of consumption. The exhaust pipe io the internal combustion engine contains a silencer ii and behind this silencer an approximately perpendicular widened piece 12, which is free at its upper end to make accessible to a fixed located near its lower end Joint 13 is pivotable and can awfneh a desiccant container 7, men. At this line piece 12 is connected to a fixed exhaust line 14. from the useful gas line 9 branches behind the filter 8, a shut-off member, i9 containing Line 15, which is designed as a pipe coil, in the exhaust pipe io arranged heat exchanger 16 and further to an outlet 17 leads with the one end of the inserted in: the line part 12, desiccant container 7 connected can be. At the other end of this container is a pipe leading to the open air is connected.

Fig. 2 shows the design of the part 12 of the exhaust pipe serving to accommodate the dry matter container 7. The exhaust line io coming from the muffler i i ends in its ascending part with a funnel-shaped extension 2o. The line part 12, which is pivotable about the joint 13, adjoins the wide end of this funnel. The upper end of this line part 12 is designed according to an arc described around the joint 13 and continues in a fixed line part 14 leading into the open. In the funnel 20 a cone 23 pushing the exhaust gas outwards is built in, which inside a mouth piece 24 for the gas line 9 branching off the gas line 9 which bil.diet a pipe coil 16 lying in the exhaust line io before this mouth piece. A discharge nozzle 25 is inserted into the mouth piece 24, the flow cross-section of which is dimensioned such that at the pressure prevailing in the useful gas line 9, a gas quantity which is only a small fraction of the compressor delivery can emerge. The outer end of the mouth piece 24 is spherical. The conical inner surface of the connecting part 26 used to connect the drying container 7 to the compressor delivery line can rest against this spherical surface. The contacting surfaces are pressed against one another by the weight of the container 7 and thus form a sufficient seal which allows the container a certain mobility. At the upper end of the line part 12 to be used in. The container is turned in by means of a wing nut27, the line part 12 to the outside. protruding pipe eats set, at its outer end, to the outside. has opening check valve 29 loaded by a weak spring 28. An inner jacket 30 , which is equidistant to it and which is only slightly larger than the outer diameter of the container 7, is firmly connected to the line part i2. The union nut 27 b..il @ det at the same time the upper one. conical closure d, this inner jacket. The jacket 3o together with the conical parts 23 and 27 adjoining its ends protects the container 7 from direct contact by the exhaust gases and thus from sooting, without significantly influencing the effects of heat .der exhaust gases on the container contents. The links 34, 35 connecting the joint 13 on the one hand with the fixed line part io and on the other hand with the pivotable part 12 have extensions 36, 37 which set the pivot angle of the line part i2. limit. The position of the line part 12 pivoted up to this limit is shown in dashed lines in the drawing.

This facility is handled as follows: After Removal of the container 7 from the compressor conveyor line is carried out at one end of the container the pipe i8 is screwed tight by means of the union nut 27, then the line part 12 pivoted out, the container 7 pushed into it and finally the line part 12 pivoted back again. In the compressor delivery line instead of the removed Another container with regenerated content is built into the container. Then: will the shut-off element in line 15. ig (Fig. i) open, it can now a small amount of gas (purge gas) determined by the width of the nozzle 215, which is contained in the Coil 16 experiences a considerable heating, into. The container interior and the vapors formed therein via the opening check valve 29 lead to the outside world. The flushing gas and the vapors could also flow out immediately into the exhaust pipe if precautions are taken to prevent it from entering to avoid soot and other contamination inside the container with certainty. When inserting and lifting the container 7 into or out of the line part 12 is used the tube i8 at the same time as a handle.

In the device according to Fig. 3, the exhaust line branches into three branch lines. 3i, 32, 33. In two of these branch lines, 3 1 and 32, a desiccant container 71, 72 is permanently installed. An air supply pipe 21, 22 also opens into the lower part of each of these two branch lines 3i, 32. The branch lines 31 and 32 unite. at their upper ends, again and thereby form nozzle-like openings 41 and 42, in such a way that a gas stream flowing through one branch line exerts a suction effect on the contents of the other branch line. At the lower ends of the branch lines 31 and 32 swing flaps 61 and 62 are arranged, which are connected by a linkage 6, 4 below and with an adjusting device 65 so that they can be adjusted together in two different positions. In one position, as shown, the branch line 31 is connected to the exhaust line and the branch line 32 is connected to the air line 22. In this case, it is determined by the flowing through the line 3i and through the mouth 41 in the direction of the arrows c. Exhaust gas air through the branch power 32 in the sense of the arrows! d sucked through. In the other position, the branch line 3i is connected to the air line 21 and the branch line 32 is connected to the exhaust line io. In this case, the exhaust gas exiting the nozzle 42 draws air through the branch pipe 3i. The swing flaps 61, 62 are held in place by a projection 66 provided on the linkage 64 and a locking bolt 67 that can be lifted out by hand in each end part. At the branch of the third branch line 33: a swing flap 63 is arranged in such a way that it feeds the exhaust gas coming from the line io either to the branch lines 3i, 32 or to the branch line 33. The branch line 33 encloses the nozzle-like orifices 41, 42 of the two other branch lines 3i, 32, so that an exhaust stream flowing through the connecting line 33 flows onto the contents of the other two. Branch lines exerts a suction effect. An adjusting rod 94 with an adjusting device 95 is connected to the swing flap 63, which in turn is held in one or the other end position by a projection 96 and a locking pawl 97 that interacts with it. The delivery line 3 coming from the compressor branches like the two branches 43 and 44, which each lead to one end of the container 7 i, 72 and each contain a shut-off valve 45, 46. Branch lines 53, 54 connect to the other ends of the container and combine to form the useful gas line 9 and likewise each have a shut-off valve 55, 56. The purge gas line 15 branching off from the useful gas line 9 behind the filter 8 forks in two parts 47, 48, each of which contains a heat exchanger designed as a pipe coil 51, 52 and a shut-off valve 39, 40. Each one of these branches 47, 48 opens into one of the branch lines 53, 54 coming from the containers 71, 72 at a point located between this container and the valve 55 or 56. The supply line 15 contains a narrow passage a5 which acts as a throttle before it branches off. From each of the branch lines 43 and: 44, also at one point between the container 71 and 72 and the valve 45 and 46 in the branch line, a secondary line: g57 and 58, the ci.n shut-off valve 49 and 5o, respectively, goes off and 'which open to the outside: the check valve 59 or 6o opens into the open.

The mode of operation is as follows: In the illustrated position of the swing flaps 61, 62, 63, exhaust gas flows in the direction of the arrows c through the branch line 31 and fresh air in the direction of the arrows d. through the branch line 32. The useful gas valves 45 and 55 are closed, the useful gas valves 46 and 56 are open. The flushing gas valves 19, 39 and 49 are open, the flushing gas valves 4o and 5o are closed. So useful gas flows in the direction of the arrows. through the container 72 arranged in the branch line 32 and releases its moisture content from the contents of this container, which is kept cool by the air flowing around it. The contents of the container 71 located in the branch line 31 are regenerated by the hot exhaust gas flowing around this container. At the same time, a flow of purge gas flowing in the direction of arrows b is passed through this container. When the regeneration is finished, all swing flaps 6.i to 63 are switched over; The exhaust gas then flows through the branch line 33 and now sucks in fresh air through the branch line 31, so that the container 71, which was previously surrounded by the hot exhaust gas, is now cooled and therefore when the dry sauna container is switched over later for the dehumidification of the useful gas is ready. At the same time as the swing flaps are switched over, the valve located in the purge gas supply line 15 is also closed, so that no further consumption of purge gas occurs. If the contents of the container 72 have absorbed sufficient moisture, the swing flap 63 is moved to the other position, then the previously closed valves 45, 55 and 40, 50 are opened, while the previously open valves 46, 56 and 39, 49 closed. The valve i9 is opened again. The useful gas now flows through the container 71, while the container 72 is now washed around by the exhaust gas and flowed through by the flushing gas, its contents being regenerated. After this regeneration is complete, all swing flaps 61 to 63 are adjusted again so that the exhaust gas flows out through branch line 33 and fresh air flows through branch line 32. At the same time, the purging gas valve i9 is closed again. This is followed by the switching of the swing flap 63 and the switching of the container 71 to regeneration and the container 72 to drying as well as the opening of the valve i9, whereby the starting position shown in the drawing is reached again; the processes described can now take place again.

Fig. 3a illustrates another possibility, the swing flap adjustment. According to this, the projection 66 of the adjusting rod has a central depression 68 to accommodate the pawl 67, so .that the swing flaps 61, 62 can also be held in their middle position shown in Fig. 3a. The aforementioned flaps are in this position after the regeneration is complete the contents of one or the other container 71 and 72, respectively. Then it won't only the container with the regenerated contents of fresh air flows around it The fresh air circulating during regeneration also remains of the other container is maintained. The flow of fresh air can for example help to dissipate heat released during moisture retention and as a result of any strong warming that is detrimental to the dehumidification effect to prevent dry matter. In the case of the establishment of Fig. 3 or 3a, it is true the alternating installation and removal of the desiccant container in the compressor feed line and avoided in the exhaust line, designed the operation of the many switching elements but rather cumbersome and requires a lot of attention. The invention therefore continues to provide arrangements in which the switchover from: drying. on regeneration by adjusting only a few, in the most favorable case only one actuator is achieved, so that on the one hand the operation is made much easier and on the other hand: the possibility of incorrect switching is largely reduced or turned off completely.

An example of a device with only two actuators to be operated is shown in Fig. 4. The two drying and regenerating dryers 71, 72 are installed in the same way in branch lines through which exhaust gas and air flow alternately as in the example according to Fig. 3. Of the useful gas and purging gas valves as shown in Fig. 3 the valves 45, 55 and 40, 50 which are closed in one operating case and the valves 6, 56 and 39, 49 which are open in the same operating case are each combined into a group. The valve plates of each group are connected to a common displacement member 69 or 70 via balance levers 73, 74, 75 wind 76, 77, 78 so that in the closed position the closing pressure is transferred to all valve cones in the ratio determined by the lever dimensions , so that a safe closing is brought about, and that on the other hand, a complete opening of all valves is achieved. The mutually facing ends of the sliding members 69 and: 70 grip. each with a projection 81, 82 in one each. Slot 83 or 84 of a plate 79 which can be displaced perpendicular to the direction of displacement of the displacement members 69, 70 . Each of the slots 83, 84 has a shorter part directed parallel to the direction of displacement of the plate 79 and a longer part extending at an acute angle to this direction of displacement. These obliquely running slot parts are parallel to each other, so that when the plate 85 is adjusted, the one sliding member, for. B. 69, in the sense of closing the connected valves, the other sliding member, z. B. 70, is adjusted in the sense of opening the connected valves. A screw suspension 85 is firmly connected to the plate 79 and engages in a nut 87 which is immovably mounted in a fixed bearing 86 and to which a handwheel 88 is connected. Furthermore, a pointer 89 is connected to the plate 79 and cooperates with a scale 9o which has two setting marks I and III.

The connecting rods 64 of the swing flaps 61, 62 and the swing flap 63 are each connected to a rod 10 or 102 which is displaceable in the longitudinal direction. Each of these rods engages with a pin 103 or io.I in a self-contained groove io5 or io6 of a disk 107 which can be rotated with the aid of a handle io8 in the direction of arrow e. The groove io5 is similar to an ellipse, so it has two points closer to the axis of rotation and two points further away. The groove io6 consists essentially. from two semicircles of different sizes. Connected to the rod io2 connected to the swing flap 63 is an arm iog which can act on the spindle of a valve i io located in the purge gas line IS and which is loaded to close by a spring iii, so that the valve is opened when the branch line 33 is closed off from the exhaust line io. The disk 107 has four projections 112 which cooperate with a resilient detent 113 so that the disk is held in four specific positions I, II, III, IV.

The mode of operation is as follows: When the plate 79 is in the position shown, its pointer 89 points to the mark I. Here, the useful gas can flow through the desiccant container 72 in the sense of the arrows a. The handle io8 of the disk io7 also assumes position I .; In this case, the container 71 is flowed around by exhaust gas, the container 72 by fresh air, the branch line 33 is closed off from the exhaust line io, the purge gas valve iio is open. Purge gas can therefore flow through the drying container 71 in the direction of the arrows b. Accordingly, the dehumidification of the useful gas takes place in the container 72 and the regeneration of the container contents in the container 71. When this regeneration has ended, the disk 107 is rotated into position II. Here, all swing flaps 61, 62, 63 are switched over and the purging gas valve i io is closed. The exhaust gas now flows through the branch line 33, while the branch line 31 is traversed by fresh air, which cools the container 71. If the container 72 has absorbed sufficient moisture, the disk io: 7 is rotated further into position III and the plate 79 is moved to its other end position, ie which the pointer 89 points to the mark III. Here, the swing flap 63 has been switched over and the purge gas valve iio has been opened. The exhaust gas now passes through the branch line 32 and sucks in fresh air through the branch line 31; furthermore, the useful gas now flows through the container 71 and is: dehumidified therein; purge gas flows through container 72 and its contents are regenerated. After this regeneration has ended, the disk io7 is turned into position IV, in this case all swing flaps are switched over again and the gas flow valve is closed again. The exhaust gas then flows through the branch line 33 and sucks in fresh air through the branch line 32. Finally, the disk 107 is rotated further into position I and the plate 79 is also brought back into position I, whereby the game begins again. To switch the two containers 71 and 722 from Eptfeuchten to regeneration, the machine operator in this exemplary embodiment only needs to operate two actuators, the handwheel 88 and the handle i o8, to complete the regeneration only the handle io8.

Again, the adjustment of the swing flaps 61 and 62 in the on, hand of Fig. 3a described. Way to be done. For that purpose only needs the Groove io6 of disk io7 to be designed so that these swing flaps in the positions II and IV of the disk 107 are in their central position.

For handling it is even easier and safer if the correct one Adjustment of all switching elements by adjusting a single manual control element can be brought about. An example: Fig. 5 shows this type.

The Nutzgasventile 45, 46 and 55, 56 as well as the Spülgasventile 39, 4o and 49 so .are ebensu as in the example according Abb..I in: combined two groups, the valves of each group to the balance beam 73, 7d-, 75 and 76 , 77, 78 connected. The end balance beams 75 and 78 of each group are connected to one another by a rod 15 carrying a piston 116. A second piston 117 is connected to the linkage 64 of the swing flaps 61 and 62 and a third piston i 18 is connected to the linkage 9.4 of the swing valve 63. These pistons are in, fixed cylinders. 119,12O, 121 movable. The piston rod 122 of the last-mentioned piston 118 acts at the same time on the spindle of a valve i io located in the purge gas line 15 and loaded to close by a spring iii in such a way that. it keeps this valve open, wend .die Schvvingklappe 63 closes the exhaust branch 33. The three cylinders are each over two lines, which in; the spaces on both sides of each piston open out, connected to three valve housings 123, 124, 12'5, in each of which a valve 126, 12'7, 128 can be moved and which are each connected to an inflow and outflow line 129 via an inflow and outflow line and a main discharge line 130 for a or liquid pressure medium are connected. The valve bodies are in; Certain angular distances, namely the housings 123 and 12 [at a distance of 90 °, arranged around a disc 107 which can be rotated in the direction of arrow e and which is designed in the same way as in the example according to FIG. 4. The slides 126 and 127 assigned to the pistons 116 and 117 engage with pins 131 and 132 in the outer groove, and the slide 128 assigned to the piston 118 engages with a pin 113 in the inner groove 105 . The housing and the slide are provided with control channels that in one. End position of each slide is one of the two spaces of the cylinder associated with this slide with the main inflow line 129 and the other is connected to the main outflow line 130 and that in the other: slide end position, these connections are interchanged.

The mode of operation is as follows: In the drawn position I of the disk 107, all slides have their outer end position. The container 72 is switched to dehumidifying., The container 71 is switched to regeneration. If the disk 107 is rotated in position II, the slide 126 does not experience any adjustment, and consequently the piston also retains. 116 its location. The sliders 127 and 128 are. adjusted inward, the pistons i, 7 and 118 move accordingly, and accordingly the swing flaps 61, 62 and 63 are swiveled and the purging gas valve iio is closed (termination of the regeneration in the container 71). When the disk continues to rotate in position III, slide 126 is moved inward and slide 128 outward. The piston 116 is thus displaced and this moves all of the valves connected to it; At the same time, the piston 118 pivots the swing flap 63 and opens the purging gas valve (switching the container 71 to dehumidifying, .the container 72 to regeneration). If the disk 107 is then brought into position IV, the slide 12.7 is moved outwards and the slide 128 is moved inwards. The pistons 117 and i 18: adjust all swing flaps 61, 62, 63 and close the purging gas valve i io (termination of the regeneration in the container 72). When the disk 107 is then rotated further to position I, the slides 1z6 and 128 are moved outwards, the piston 116 switches the valves connected to it, the piston 118 switches the swing flap 63 and opens the purging gas valve iio (dehumidification in the container 72, regeneration in the container 71). This restores the initial status and the game can begin again. The pressure medium for adjusting the pistons 116, 117, 118 is expediently one that is already present during operation of the machine system, for example the useful gas compressed by the compressor or pressurized lubricating oil. Instead of such a pneumatic or hydraulic auxiliary force, an auxiliary force of another type, e.g. B. Electricity, serve.

Claims (7)

PATENT CLAIMS: i. Process for drying in a compressor with Brennkraftmasch.inen - eel drive compressed gas (useful gas) by means of moisture-binding and substances that can be regenerated by heat, which are stored in a pressure-resistant container (dry material container) are included, characterized in -that alternately the one time the useful gas passed through the interior of the container, which remains without external heat input and the other time hot exhaust gas from the pulverulent engine for heat exposure is brought to the outside of the container, the interior of which here with the Outside air can come into contact. 2. The method according to claim i, characterized in that that during the heat action of the exhaust gas on the desiccant container through the inside of the same heated dried gas (rinsing gas) passed in an amount which is only a small fraction of the amount of gas conveyed by the compressor. 3. The method according to claim i and 2, characterized in that two desiccant containers (71, 72) alternately so in each one of their interior pulling through useful gas and flushing gas flow and in each of them flowing around them from the outside: exhaust gas and fresh air flow switched «ground that always one of the containers is flowed through by the useful gas for a certain period of time, while the other container in the same time interval first flows around the exhaust gas and is flowed through by the flushing gas and then by: the flushing gas supply shut off and by; Fresh air is flowed around. 4. Procedure according to Claim 3, characterized in that the container through which the useful gas flows at least fresh air flows around the outside during part of the period of time of this flow will. 5. Device for performing the method according to claim i, characterized in that that a desiccant container (j) in the Verdichterdruckleihu ing (3, 9) can be switched on is that it is flowed through by the useful gas and: that this container (7) further after its expansion. the compressor pressure line (3, 9) into the exhaust line (i o, 12) the internal combustion engine (2) can be used that he outside of: the exhaust gases flow around and that the, thereby, inside itself forming vapors can escape (Fig. 2). 6. Implementation facility of the method according to claim i and 2, characterized in that the feed line (15) for the desiccant container (7) while exhaust gas flows around it The purge gas to be supplied is a heat exchanger which is also purged by the exhaust gas (16) and a nozzle (25) which determines the amount of flushing gas (Fig. 2). 7. Device according to claim 5, characterized in that the for receiving the desiccant container (7) certain piece (12) of the exhaust line (io, 12, 14) about a pivot point near one end (13) is pivotable so that the Container (7) with the pipe section (12) swung out over its other end! can be introduced into or removed from the line piece (12) (Fig. 2). B. Device according to claim 5 to 7, characterized in that the desiccant container (7) to be used in an at least approximately perpendicular piece (12) of the exhaust line (io, 12, 14) extends with its lower thread (2.6) by its own weight the orifice (24), which is fixed in the exhaust line (io), of a line (i5) supplying the flushing gas is supported, at least one of the contacting parts (24, 26) having a spherical contact surface (Fig. 2). Device for carrying out the method according to claims 1 and 3, characterized in that the exhaust line (io) is subdivided into three branch lines (31, 32, 33), and two (31, 32) of these branch lines each have a desiccant container (71) , 72) is permanently installed that switching elements for the useful gas (45, 46 and # nd.55, 56), for the flushing gas (39, 4 and 49, 50)> for exhaust gas and fresh air (61, 62, 63) in such a way are provided that each of the two containers (71, 72) can alternately flow through one of the useful gas, while the other in. The same period of time initially from. Exhaust gas flows around and. flushing gas flows through it and, then, the flushing gas can be switched off and fresh air can flow around it (Fig. 3 to 5). ok Device according to claim 9, characterized in that the exhaust branch lines (34, 32, 33) merge again behind the desiccant containers (71, 72) to form a line (14) in such a way that the exhaust gas flowing through the branch line (33) which does not contain a container arrives the junction on the: contents of the other branch lines (31, 32) exerts a suction effect (Fig. 3). i i. Device according to Claim g, characterized in that the switching elements for the useful gas (45, 46 and 55, 56) and the flushing gas (39, 40, 49, 50) are connected to one another in such a way that by adjusting only one actuator (handwheel 88) .The switching of the desiccant container (71, 72) from the useful gas flow to the flushing gas flow and vice versa is brought about (Fig. 4). 12. Device according to claim g, characterized in that the switching elements for exhaust gas and fresh air (61, 62, 63) and a switching element on and off the purge gas flow (iio) so on., Two self-contained cam tracks (io5 , io6) containing rotatable actuator (107, io8) are connected that the flow of exhaust gas and fresh air to the desiccant containers (71, 72) regulating switching elements (61, 62) at every half. Rotation, that the exhaust gas temporarily to the containerless Z.we'igleiltung (33) leading switching element (63) and the purging gas switching element (iio), however, are switched with each quarter turn of this actuator (107, 108) (Fig., 4). 13. Device according to claim g for performing the method according to claim 4, characterized in that the switching elements (61, 6 @ 2) which are arranged in the branch lines (3.1, 32) provided with containers (71, 72), except in their end positions: are also adjustable in their central position, so that at. this last-mentioned setting and with the simultaneous passage of the exhaust gas through the third branch line (33), the two first-mentioned branch lines (31, 32) are simultaneously traversed by fresh air (Fig. 3a). 14. EinrichtuIag according to claim g, 11 and 12, characterized in that the switching elements to be adjusted simultaneously for each switching process, i.e. the useful gas and purging gas valves (45, 46, 55, 56 and. 39, 40, 49, 50) , .the exhaust gas fresh air switching elements (61, 62) and the individual switching elements for exhaust gas (63) and flushing gas (iio) each with one by means of an auxiliary force in one. or other direction adjustable force member (116, 117, 118) are connected, .that for each force member an auxiliary force action on the same regulating control member; (126, 127, 128) and an actuator (1o7, 108) determining the number and sequence of these actions are provided in such a way that the correct switching can only be achieved by gradually moving this one actuator into certain successive positions (I to IV). of the two desiccant containers (71, 72) is brought about from drying on the one hand to regeneration and subsequent re-cooling on the other hand, and vice versa (Fig.5).