DE2701006A1 - Freeze drying of gas - in vertical gas and coolant heat exchanger units in closed pitch circle arrangement - Google Patents

Abstract

Appts. for the freeze drying of gas, e.g. of compressed air, passes the gas through a gas/gas heat exchanger, through a gas/coolant heat exchanger, and again through the gas/gas heat exchanger. All heat exchangers consist of several identical vertical units which are arranged on one or several coaxial closed curves. Arrangement facilitates an extension of the capacity to match any future greater flow rates. It ensures high throughputs in a min. of space.

Description

Device for cold drying of gas,

in particular compressed air The invention relates to a device for Cold drying of gas, in particular compressed air, with a gas / gas heat exchanger as well as a gas / refrigerant heat exchanger in an essentially vertical arrangement, wherein the gas to be dried successively the gas / gas heat exchanger, the Gas / refrigerant heat exchanger and then the gas / gas heat exchanger again flows through in a continuous cycle.

Such an arrangement is from the applicant's DT-Gbm 73 25 813.6 known. The refrigeration dryer described in this publication has already has many advantages and also works advantageously in the countercurrent process, whereby a significant energy saving is achieved. The gas to be dried is first introduced into a gas / gas heat exchanger, where the gas receives some of the heat is withdrawn. The gas then flows from this gas / gas heat exchanger to a Gas / refrigerant heat exchanger, where the dew point of the gas to be dried is so high is reduced that the moisture contained therein as well as partly further Impurities deposited will. After removing the moisture the gas is fed back to the gas / gas heat exchanger in countercurrent in order to Now warm up dry gas again and at the same time the supplied still moist To pre-cool gas.

Compared to arrangements already known, this one stands out known device for cold drying in particular also characterized in that the natural The gradient of the air in its various temperature states is used, whereby a considerable reduction in the otherwise usual pressure loss is achieved. This natural gradient results from the fact that the first introduced into the refrigeration dryer warm air can flow downwards as it cools, which is its natural gradient therefore corresponds because gas compression occurs on cooling. The same The direction of flow is from top to bottom with the gas / refrigerant heat exchanger provided so that here too the gas through the heat exchanger along its natural Gradient flows. Conversely, the gas flows through the gas / gas heat exchanger when it is reheated from the bottom up, which is also the natural need of warming up and thus corresponds to gas that is becoming lighter. The downward movement of the still with Contaminants of the loaded gas to be cooled down through the heat exchangers is also advantageous because it not only reduces the moisture but also possibly

Contained dirt as well as oil residues collect below and in a simple Way can be deducted.

The known refrigeration dryer also has the advantage that the two Heat exchangers are in the form of insertable inserts, so that when a Damage or clogging of a heat exchanger this relatively easy can be pulled out of the boiler housing and repaired or replaced.

The boiler-like design also has a significant disadvantage with itself: the boiler size determines the maximum possible Performance of the Refrigerant dryer. An adjustment to higher performance is therefore not possible. Rather, it would be necessary to have several refrigeration dryers of the known type in parallel to switch, which is inexpedient for spatial reasons, but also for reasons of cost is.

But there is also a downward adjustment in the known refrigeration dryer makes little sense, since on the one hand the external dimensions do not change at all would, on the other hand, if a completely new design is not carried out but also a reduction in investment costs is hardly to be expected, since essential Parts of the dryer equipment unchanged even with smaller nominal power requirements must be taken over.

An adjustment to the required throughput, either during the manufacture of the refrigeration dryer, or by modifying an already manufactured one Refrigeration dryer, is a considerable advantage in many cases. If the requirements As throughput grew over time, it was more conventional to use Refrigeration dryer previously required to either provide additional refrigeration dryer, or the previous low-performance refrigeration dryer with a new refrigeration dryer to replace greater power.

But not only the expandability of a refrigeration dryer is important, but also the possibility of producing the most precise one possible Adaptation of the throughput of the refrigeration dryer to the special requirements of the To be able to make the customer. On the one hand, this can save space On the other hand, the arrangement is cheaper if there is less exchanger surface is needed than would normally have been foreseen.

It would also be beneficial to have a range of different refrigeration dryers To be able to offer performance, its size and its price with the respective nominal output are in harmony, whereby it would be of particular advantage if different for them huge Refrigeration dryer requires as few different components as possible would be.

The object of the invention is to create a refrigeration dryer that is designed so that it can be adapted to a required performance without major Enables effort and also in the direction of greater throughput rates without major Cost is expandable.

According to the invention the object is achieved in that in a device for the cold drying of gas of the type mentioned, the heat exchangers in each case of several identical, essentially vertical, arranged parallel to one another Exchanger elements exist whose axes are on one or more coaxial to one another closed curves.

With this basic construction it is possible to increase the number of To choose exchanger elements according to the performance requirements, with the cost for the exchanger elements make up most of the cost of the dryer and thereby a very good adaptation of the manufacturing costs to the required performance results. It is also possible afterwards without great difficulty to add more exchanger elements, thereby increasing the nominal output To adapt to requirements.

The construction becomes particularly simple if according to an advantageous one Further development of the invention, the axes of gas / gas heat exchangers and gas / refrigerant heat exchangers lie on only one closed curve, for example on a circle.

To further simplify the construction and expand it to facilitate greater performance with it are according to yet another embodiment of the invention gas / gas heat exchanger and gas / refrigerant heat exchanger one above the other arranged and at least some of the exchanger elements of the Gas-/ Gas heat exchangers are coaxial with corresponding exchanger elements of the gas / refrigerant heat exchanger.

By adding just a single column of exchange elements this makes it possible for both gas / gas heat exchangers and gas / refrigerant heat exchangers to increase the throughput at the same time.

The required number of components is further reduced, when the exchanger elements each lying on a closed curve from each other have the same distance. This is especially true if according to yet another Further development of the invention, each lying on a closed curve Exchanger elements are connected at their ends with two collecting lines each, which have substantially the shape of the closed curve, the one manifold for one exchange medium and the second collecting line for the second exchange medium is provided, and if the components mentioned form an exchanger module. By the same distances can then be of the same type for the various manifolds Components are provided.

The interchangeability is further improved when the four manifolds of the exchanger module each have a connection piece via which a connection to further modules and / or separators, filters, inputs and outputs of the refrigeration dryer can be produced.

Instead of arranging the refrigeration dryers one above the other, it can also be expedient be, especially for reasons of space, the diameter of the closed curves of the To choose modules so that they can be arranged one inside the other.

Finally, it is also an advantage if in accordance with yet another Embodiment of the invention, the manifolds are provided with approaches the other exchanger elements attached, z. B. can be flanged. on this way is e.g. B. the expansion of the system is particularly easy.

Further details, advantages and possible uses of the invention result from the attached representation of exemplary embodiments as well as from the following description.

1 and 2 show two sectional views of a device for Prior art refrigeration drying of gas; Fig. 3 is a cross-sectional view an embodiment of the device according to the invention for cold drying of gas; Fig. 4 is a sectional view taken along line A-B of Fig. 3; Fig. 5 shows a further embodiment the device according to the invention for cold drying of gas; Fig. 6 is a sectional view along lines A-B of Figure 5; FIG. 7 is rotated by 450 with respect to FIG Partial sectional view to show the pipe connection between the lower and upper Ring line; 8 shows yet another embodiment of the refrigeration dryer according to the invention for gas; and FIG. 9 is a sectional view taken along line A-B of FIG. 8.

In Fig. 1, a known type of refrigeration dryer 10 is shown.

It comprises a vertically arranged gas / gas heat exchanger 12 and a gas / refrigerant heat exchanger 14 inserted parallel to it. Inside of the gas / gas heat exchanger 12 is a heat exchanger insert 18, the is equipped with cooling coils 24.

The gas to be treated, for example coming from a compressor Compressed air, is fed to the gas / gas heat exchanger 12 via an inlet 28, with the compressed air temperature, for example, the compressed air flows into the inlet Cooling coils 24 from top to bottom and cools down in the process.

It exits at 30 (Fig. 1), 30a, 30b (Fig. 2) and passes over Filters 32a and 32b and a space 38 for the inlet of the gas / refrigerant heat exchanger 14th

The gas / refrigerant heat exchanger 14 also contains a heat exchanger insert 36 with cooling coils 46. The flowing into the gas / refrigerant heat exchanger 14, to a temperature of e.g. B. 200 C cooled gas flows through the heat exchanger insert 36 and leaves this with a temperature of + supplied, where possibly not with the Condensation water deposited or not retained by the previous filters Dirt residues and oil particles are caught. This then comes from this filter cold gas is returned to the gas / gas heat exchanger 12, where it is attached to the cooling coils 24 is passed up and out of the outlet 34. This warms up Gas back on to a temperature suitable for use.

The refrigerant supplied via a line 44 flows through the cooling coils 46 and exits again via line 50.

Both heat exchangers and the three filters are in one pressure vessel 16 housed, which can be closed with a cover 17. Through this The pressure vessel, which encloses all components of the refrigeration dryer, is the Throughput is limited to a certain maximum value, which by the size of the pressure vessel is fixed. An adaptation to larger throughputs is not possible without changing the overall construction.

These disadvantages are highlighted in the following additional figures illustrated embodiments bypassed. So in Fig. 3 is a first embodiment an improved according to the invention compared to the prior art described above Refrigeration dryer shown in longitudinal section, while Fig. 4 is a cross section along the line A-B of FIG.

Here, too, there is the device for cold drying of gas as with State of the art comprising a gas / gas heat exchanger 12 and a gas / refrigerant heat exchanger 14. Both heat exchangers are arranged coaxially one above the other. This arrangement is advantageous according to the invention because it reduces the size of the various ring lines can all be chosen the same, so that these are essentially made of prefabricated Components can be produced. In addition, the heat exchanger columns that both include the gas / gas heat exchanger as well as the gas / refrigerant heat exchanger, can be built, replaced or supplemented as a unit, so that the Manufacturing, maintenance and expansion result in simplifications. In the drawings are the precautions required for this purpose, such as flange connections, Screw connections and the like, not shown for reasons of simplicity.

The refrigeration dryer according to the invention is modular in several respects built up. On the one hand, the construction of the gas / gas heat exchanger 12 (see Fig. 3) essentially identical to the gas / refrigerant heat exchanger 14, apart from of slight differences in the devices for feeding the individual media. An air inlet collector 45 is provided in the gas / gas heat exchanger, in FIG after being fed through a connecting piece 82, the gas to be dried is collected and then the individual heat exchanger tubes 62 of the combination the end Gas / gas heat exchanger 12 and gas / refrigerant heat exchanger 14 is supplied. A collecting space 47 which is practically identical to the air inlet collector 45 is at the bottom Arranged at the end of the exchanger columns and takes the one emerging from the tubes 62 Gas on. The annular collecting spaces 45 and 47 are therefore practically identical, because the same dimensions are provided in both cases and in each case in a side wall the tubes 62 of the heat exchangers end in a similar manner.

The attachment can be done by welding, but also for the purpose a flange connection or screw connection for better interchangeability be provided.

The two further collecting spaces 42 and 74 are similarly identical built up, which are used in the gas / gas heat exchanger outside the pipelines 62 take up flowing gas and feed it to the heat exchanger (room 74) or

take up gas emerging from the heat exchanger (collecting space 42) and to be delivered via a connecting piece 76. Very similar collection rooms could also provided in the gas / refrigerant heat exchanger 14 for the refrigerant circuit be.

Instead of rooms 65 and 80, each could have its own connections Have for the refrigerant, an annular space can also be provided for the gas the gas / gas heat exchanger 12 is provided. But also with the individual heat exchanger elements 59, the construction of which, for example, from the earlier patent application P 26 54 253.0 emerges and is therefore not to be described in detail here, can build up modular. So it can be seen in Fig. 4 that around four core tubes 62 is an outer tube 61 through which in the region of the gas / gas heat exchanger 12 from the air collector 74 cold air from the bottom up into the upper air outlet collector 42 flows, while in the area of the gas / refrigerant heat exchanger an inside The refrigerant located in the pipe 61 washes around the pipes 62, the refrigerant for example, fed to a lower refrigerant collector 65 and after flowing through of the outer tubes 61 are collected again at the upper refrigerant collector 80 and withdrawn will. The exchanger elements 59 could now take place four core tubes 62 also have a different number of core tubes, depending on the refrigerant and throughput per element.

Likewise, the number of heat exchanger elements 59 could be the respective If necessary, it could be adapted, for example, only the four in Fig. 4 with solid lines Exchanger elements shown in lines may be provided at higher throughput performance, it would be just as possible to add more exchanger elements between to provide those already shown, with the construction shown in FIG There would be space for a total of twelve elements, tripling that Throughput capacity. As the exchanger elements because of their relative complicated construction accounts for a significant proportion of the total cost of the refrigeration dryer make up, it succeeds by correspondingly lower numbers of exchanger elements with low throughput requirements, the total costs of the refrigeration dryer to be kept accordingly low.

An even more extensive adaptation would be possible in that columnar Heat exchangers, such as those of the gas / gas heat exchanger 12 with its annular spaces 42 and 74 are represented, are stacked several times on top of one another, in which case any flow modes by connecting the individual annular spaces accordingly for the various heat exchanger media are possible. It could e.g. B. several Gas / refrigerant heat exchangers are arranged one above the other, with each gas / refrigerant heat exchanger another refrigerant or a refrigerant with a different temperature is supplied.

The ring-shaped construction of the various heat exchangers makes it possible it to provide further dryer elements in the center of the heat exchanger without these change the external dimensions of the refrigeration dryer. For example from the lower air outlet collector 47 the now maximally cold and partly still air laden with mist droplets, dirt and oil droplets either directly via a corresponding pipe (not shown) or via further dryer elements, like one Cyclone separator 84, calming room 88, chimney 92, filter 94, get into the annular space 74, from where they are in the manner already described Countercurrent flows through the gas / gas heat exchanger and over the upper air outlet collector 42 and the outlet connection 76 leaves the refrigeration dryer.

The optional additional elements are mainly used to better separation of entrained oil droplets, water droplets and dirt particles of the treated air to allow. In this context, reference is made to the patent application P 26 54 253.0 referenced by the applicant.

In Fig. 5 is a further embodiment of the refrigeration dryer according to the invention shown in the gas / gas heat exchanger 112 and gas / refrigerant heat exchanger 114 are arranged coaxially one inside the other. The embodiment shown here corresponds in many parts of the embodiment shown in FIG. To make things easier the overview has therefore been given corresponding parts with the same reference numbers and prefixed 111 designated.

By nesting the two heat exchangers, this is possible it to reduce the overall height of the device. The reduction in height, however, requires additional measures to prevent the pre-cooled gas exiting the gas / gas heat exchanger To collect gas, which happens in an additional collection space 175, then one of this collecting space upwardly leading pipe 177 (see FIGS. 6 and 7), which is in the plenum 173 opens, which is connected to the core tubes of the gas / refrigerant heat exchanger 114 is in communication. The pre-cooled gas flows from this (compared to Fig. 3) Collector 173 now located at the upper end of the refrigeration dryer into the core tubes of the gas / refrigerant heat exchanger 114 and pours into the lower air outlet header 147, where it has reached its lowest temperature of around 1.5 ° C. Separated liquid collects in both collector 175 and collector 147 and can be withdrawn from here will. This could now be done from collecting space 147 Gas directly into the collecting space 174 to be passed through the gas / gas heat exchanger as it ascends to be rewarmed and then to exit via the collector 142 and the nozzle 176.

Optionally, however, to improve the water, blood and dirt separation, as already in the embodiment shown in Fig. 3, In the center of the refrigeration dryer there is again a cyclone separator 184, a calming room 188, an adjoining chimney 192 and finally a filter arrangement again 194 should be provided. In this case the air coming from the filter would like in the embodiment of FIG. 3 in a space 183 around the chimney back to collector 174. Instead, you can also use the external Pipes of the gas / refrigerant heat exchanger another pipe 199 are laid, whose lumen is connected to a collector 181, which in turn is connected to filter 194 has. This has the advantage that the lumen of the tube 199, through which the still maximally cold gas flows back down into the collector 174, at the same time for the thermal insulation of the gas / refrigerant heat exchanger the adjacent gas / gas heat exchanger 112 is used.

In this embodiment, the refrigerant is supplied from below via the plenum 163 and is after the refrigerant the core tubes 162 of the gas / refrigerant heat exchanger and located in the collecting space 180 has collected, via a corresponding line at the upper end of the refrigeration dryer deducted.

Here, too, it would be easily possible and in many cases useful, compared to the embodiment shown in FIG. 5 even further with regard to to provide a standardized embodiment of the individual refrigerant dryer elements. For example, the annulus 174 and 142 could be made completely identical. If the isolation space 199 is omitted, the annular spaces are also standardized of gas / gas heat exchangers and gas / refrigerant heat exchangers possible, if also an identical construction because of the different diameters not is possible.

In FIG. 6 there are again only four outer tubes for each Heat exchanger shown. Of course, a smaller or a larger number of such exchanger elements can be provided, as is shown in FIG. 6 is indicated. In the present case, the two heat exchangers can even be different Have numbers of elements 59, which can be favorable under certain circumstances can. It should be noted that because of the connecting line 177 (see also Fig. 7) not the entire circumference of each heat exchanger ring for the arrangement can be used by exchanger elements.

Needless to say, the exchanger elements in each heat exchanger can also lie on several arcs instead of just on one as shown in the figures. Further heat exchanger units can also be used be placed around the two units shown coaxially, if the refrigeration dryer includes further heat exchanger stages.

Instead of arranging the exchanger elements in a circle, there are also others closed curves, for example an approximate rectangle or square shape often expedient. Such a shape is different from that shown in Figs third embodiment of the device according to the invention used.

Here, too, there are gas / gas heat exchangers 212 and gas / refrigerant heat exchangers 214 coaxially interleaved. Instead of the ring-shaped collecting spaces with a rectangular one Cross-section are provided in this embodiment, however, the pipelines have certain structural advantages, e.g. B. from individual pipe sections and Tubular arches can be put together.

The gas to be dried is fed into a collecting pipe via the nozzle 282 245, to which the core tubes 262 of the gas / gas heat exchanger 212 are soldered, welded on or flanged or screwed on for better interchangeability are. Instead of the collecting space 174, a collecting pipe 274 is provided, around the purified cold air flowing upwards in countercurrent into the lumen of the outer one Introduce pipe 261 of the gas / gas heat exchanger, from where it flows through of the exchanger is collected in the collecting pipe 242 and fed to the outlet 276.

Instead of the collecting space 175, there is also a collecting pipe 275 for receiving of the pre-cooled gas provided. Arrived via an upward line 277 this precooled gas then into the pipeline corresponding to the collecting space 173 273. The core tubes of the gas / refrigerant heat exchanger 214 are supplied from there, which open into a lower manifold 247. This lower manifold 247 stands with a cyclone separator also provided here, but not absolutely necessary 284 via a pipe 248 in connection. In addition, a calming room 288 and again a filter 294 can also be provided. In this case the calming room is available 288 with the filter 294 via a pipe 292 in connection. From the filter arrangement 294 the gas reaches the collecting ring via an additional pipe 272 (see FIG. 9) 274. From this collecting ring, the one with the lumen of the outer tube of the gas / gas heat exchanger 212 is in connection, the gas is heated to the already mentioned Collecting ring 242 to be delivered to the consumer via outlet 276. For the refrigerant supply and discharge are not in the illustrated embodiment special manifolds provided. However, this can be done for reasons of standardization be quite an advantage.

The advantage of the construction shown is also in particular in that the pipes serving as collecting spaces are composed of elements which are commercially available as finished parts.

Patent claims a Blank page

Claims (9)

Claims: 1. Device for cold drying of gas, in particular Compressed air, with a gas / gas heat exchanger and a gas / refrigerant heat exchanger in a substantially vertical arrangement, with the gas to be dried successively the gas / gas heat exchanger, the gas / refrigerant heat exchanger and again the Gas / gas heat exchanger flows through in a continuous cycle, thereby characterized in that the heat exchangers (12, 14; 112, 114; 212, 214) each from consist of several identical, essentially vertical exchanger elements (59), their axes on one or more coaxial closed curves (Fig. 4, 6, 9). 2. Apparatus according to claim 1, characterized in that the axes of gas / gas heat exchangers and gas / refrigerant heat exchangers to only lie on a closed curve. 3. Apparatus according to claim 2, characterized in that the curves Circles are. 4. Device according to one of claims 1 to 3, characterized in that that gas / gas heat exchanger (12) and gas / refrigerant heat exchanger (14) one above the other are arranged and that at least some exchanger elements (59) of the gas / gas heat exchanger (12) coaxial with corresponding exchanger elements (59) of the gas / refrigerant heat exchanger lie. 5. Device according to one of claims 1 to 4, characterized in that that the exchanger elements (59) each lying on a closed curve have the same distance from each other. 6. Device according to one of claims 1 to 5, characterized in that that the exchanger elements (59) each lying on a closed curve connected at their ends to two collecting lines (242 and 245 or 274 and 275) are, which have substantially the shape of the closed curve, one Collecting line (242 or 274) for the one exchange medium and the second collecting line (245 or 275) is provided for the second exchange medium, and that said Components form an exchanger module (e.g. 212). 7. Apparatus according to claim 6, characterized in that the four Collectors (e.g. 242, 274, 245, 275) of the exchanger module (212) each have one Have connecting pieces (z. B. 276, 282), via which a connection to other Modules and / or separators (288), filters (294), inputs and outputs (282 or 276) of the refrigeration dryer can be produced. 8. Apparatus according to claim 5 or 6, characterized in that the diameters of the closed curves of the modules (112, 114; 212, 214) are selected in this way are that the modules can be arranged one inside the other. 9. Device according to one of the preceding claims, characterized in that that the collecting lines are provided with approaches to which the exchanger elements (59) attached, e.g. B. are flanged or screwed on.