DE4118289A1 - Compact heat exchange appts. - for refrigeration dryer in compressed air plant - Google Patents

Abstract

Heat exchange equipment for refrigeration dryers in compressed air plants consists of an air/air heat exchanger (1), in the form of a plate heat exchanger, and a refrigerant/air heat exchanger (2) in the form of a combined tube/plate heat exchanger. Pref. the heat exchangers (1,2) are arranged alongside or on top of one another and are joined together as a structural unit. USE/ADVANTAGE - The equipment is useful for prodn. of absolutely dry compressed air for use e.g. in the foodstuff and paper industries and in medical applications. It has a small volume and is inexpensive to mfr.

Description

The invention relates to a heat exchanger device in the preamble of the claim 1 specified genus.

Compressed air systems of the type of interest here serve by means of a compressor generated and under a pressure of z. B. to provide up to 25 bar of compressed air. This compressed air, however, like atmospheric air, at least in Europe Areas with a high moisture content corresponding to a relative humidity 80% and more. For many applications, e.g. B. in food and paper industry or in the medical field, however, absolutely dry air is required. It is therefore known to the compressed air emitted by the compressor through a refrigeration dryer before it is put to its intended use, and in this refrigeration dryer completely remove the moisture.

Air is usually dried in such a way that the air coming from the compressor heated air first in an aftercooler to a temperature of e.g. B. 35-55 ° C is cooled. The air is then passed through a heat exchanger device has an air / air heat exchanger and a refrigerant-air heat exchanger.  

The air / air heat exchanger serves the purpose of being at approx. 35-55 ° C Compressed air on the one hand on z. B. 20 ° C to cool and on the other hand in countercurrent Incoming, strongly cooled compressed air coming from a water separator, for example warm to room temperature to prevent the outside from being too cold A cold bridge is created in air-carrying lines or apparatus.

In contrast, the refrigerant / air heat exchanger serves the purpose Compressed air coming in, cooled to approx. 20 ° C by means of a refrigerant, e.g. B. Frigen to cool to their dew point, which is usually 2-3 ° C. This will the refrigerant in a known manner by means of a compressor and a condenser liquefied, then expanded through the refrigerant / air heat exchanger and thereby to a temperature of z. B. minus 2 ° C at its input and plus 4 ° C brought its output, and then fed back to the compressor. The thereby on their dew point cooled air is passed through the refrigerant / air Heat exchanger supplied to a water separator, in which the moisture is completely men is withdrawn, and then passed through the air / air heat exchanger again by it while cooling the still warm air coming from the compressed air system Compressed air is heated to about room temperature.

In the known heat exchanger devices of the type described there are two heat exchangers made of nested, provided with fins or the like, preferably pipes made of copper or brass. Such heat exchangers correspond fully to the required in terms of the required heat transfer Claims, however, also have two major shortcomings. A lack in that the manufacture of the heat exchanger because of the variety of sweat required stitching is comparatively complex. Above all, the fact that the heat build-up disturbs have a large construction volume, correspondingly large cladding and insulation require materials and therefore also a refrigeration dryer with considerable dimensions weight and considerable weight.

The invention has for its object the heat exchanger device of the beginning designated genus so that it has a comparatively small volume and is cheaper to manufacture.  

The characterizing features of claim 1 serve to achieve this object.

The invention has the advantage that a heat exchanger device in Compact design was created, which makes it possible for the entire refrigeration dryer required construction volume up to about a third of the previously required volume wrestle. Since the heat exchanger of the heat exchanger device according to the invention are also preferably made of aluminum, the invention also leads to a significant weight reduction. Finally, the heat exchanger according to the invention Device inexpensive to manufacture, which increases the total cost of the refrigeration dryer let it decrease noticeably.

Further advantageous features of the invention emerge from the subclaims.

The invention is described below in conjunction with the accompanying drawing Embodiments explained in more detail. Show it:

Figure 1 is a schematic side view of a first embodiment of the inventive heat exchanger device.

FIG. 2 shows the top view of the heat exchanger device according to FIG. 1;

Figure 3 is a view of the heat exchanger device in the direction of an arrow X of Figure 1, wherein a collecting box provided with an inlet flange along the line III-III of Figure 2 shown in section...;

Fig. 4 is a section along the line IV-IV of Fig. 3;

Fig. 5 is a side view of a heat exchanger block of an air / air heat exchanger, the heat exchanger device according to Figures 1 and 2.

Fig. 6 is a plan view of a passage for the one heat exchange medium of the heat exchanger block along the section line VI-VI of Fig. 5;

Fig. 7 is a plan view of a passage for the other heat exchange medium of the heat exchanger block taken along section line VII-VII of FIG. 5;

Fig. 8 is a side view of a heat exchanger block of a refrigerant / air heat exchanger shear of the heat exchanger device according to Fig. 1;

Fig. 9 is a plan view of the heat exchanger block taken along section line IX-IX of Fig. 8;

FIG. 10 is a view of the heat exchanger block according to Figure 8 in the direction of an arrow Y.;

FIG. 11 is a schematic side view of a second embodiment of to the invention OF INVENTION heat exchanger device;

FIG. 12 shows a plan view of the heat exchanger device according to FIG. 10 with the view of a detail C shown in the direction of an arrow Z;

FIG. 13 is a view of the heat exchanger device according to FIG. 11 in the direction of an arrow V and on an enlarged scale;

FIG. 14 is a section along the line XIV-XIV of Figure 12 in enlarged scale.

Fig. 15 is a side view of a heat exchanger block of a combined air / air and refrigerant / air heat exchanger, the heat exchanger device of Fig. 11; and

FIG. 16 is a plan view of the heat exchanger block taken along section line XVI-XVI of Fig. 15;

FIG. 17 shows a view of the heat exchanger block according to FIG. 15 in the direction of an arrow W; and

Fig. 18 is a plan view of the heat exchanger block taken along section line XVIII-XVIII of Fig. 15.

The heat exchanger device according to Fig. 1 and 2 comprises an air / air heat exchanger 1 and a refrigerant / air heat exchanger 2. Both heat exchangers 1 and 2 are arranged one above the other according to Fig. 1, wherein the refrigerant / air heat exchanger 2 under the air / air heat exchanger 1 is, although it could also be reversed.

The air / air heat exchanger 1 ( Fig. 1) consists of a plate heat exchanger and contains a heat exchanger block 3 ( Fig. 5-7) with passages 4 and 5 made in plate construction, each in the direction of the arrows, ie predominantly in counterflow, through which air flows. The air enters, as shown in FIGS. 6 and 7, laterally at one end of the passages 4 and 5 and in the longitudinal direction at the opposite end. The passages 4 and 5 are also arranged alternately one above the other in accordance with FIGS. 4 and 5.

Each passage 4 is of two parallel to the longitudinal direction of the heat exchanger block 3 , to the left in Fig. 6 end of the heat exchanger block 3 strips 6 and 7 with a substantially square or rectangular cross-section and two arranged above or below the same over the entire length and Width of the heat exchanger block 3 extending plates 8 are formed. At the left end in FIGS. 5 and 6, the passages 6 are open. In contrast, the passages 4 are completed at the right end in FIGS. 5 and 6 by strips extending over the width of the heat exchanger block 3 , while at the same time the strips 6 are shorter than the strips 7 , so that the passages 4 accordingly in FIG. 6 are not right end, but open to the side and the air can flow in from the side in the direction of the arrow. In the passages 4 , usual slats 10 are expediently inserted, which are only partially shown in FIG. 5 and whose passages are deflected along a line 11 by 90 ° according to FIG. 6.

In contrast, each through 5 is shown in FIG. 5 and 7 of two exchanger blocks to the longitudinal direction of the heat-3 parallel, adjacent to the right in Fig. 7 the end of the heat exchanger block 3 strips 14 and 15 with a substantially square or rectangular cross section and two further above or arranged below the same, formed over the entire length and width of the heat exchanger block 3 plates 8 . At the right end in FIGS. 5 and 7, the passages 5 are open. In contrast, the passages 5 at the left end in FIGS. 5 and 7 are closed off by strips 16 extending over the width of the heat exchanger block 3 , while at the same time the strips 14 are designed as strips 15 , so that the passages 5 according to FIG. 7 do not reach the left end , but to the side, expediently open to the same side as the passages 4 and the air can flow in from the side in the direction of the arrows shown. In the passages 5 lamellae 17 are expediently inserted, which are only partially visible in FIG. 5 and whose passages are deflected along a line 18 by 90 ° according to FIG. 7.

The strips 6, 7, 9 and 16, each arranged between them plates 8 and arranged between each two plates 8 slats 10 and 17 are such übereinanderge stacks, as is known per se from produced in plate-type heat exchangers, and arranged such that alternately a passage 4 or 5 is formed and the heat exchanger block 3 is completed up and down by a plate 8 each. The plate 8 and possibly also the strips 6, 7, 9 and 16 are preferably made of aluminum plated with a solder and are first stacked in a manner known per se and then soldered to one another in an air or vacuum oven or also in a flux bath.

The strips 6 and 14 , the strips 7 and 15 and the strips 9 and 16 are expediently of identical design, so that, according to FIGS. 5 and 7, a symmetrical and particularly inexpensive production of the heat exchanger block 3 results. The number of passes 4 and 5 depends on the required performance of the Wärmetau block 3 .

The refrigerant / air heat exchanger 2 ( Fig. 1) consists of a combined tube / plate heat exchanger and contains a heat exchanger block 20 ( Fig. 8 to 10) with passages 21 for a refrigerant and passages 22 for the compressed air, the Passages 21 and 22 each in the direction of the arrows shown in FIG. 9, ie predominantly in direct current, through which the refrigerant or the compressed air flows.

The passages 21 for the refrigerant consist of tubes with a round or preferably rectangular or square cross section, which are arranged between two plates 23 each extending over the length and width of the heat exchanger block 20 . Each passage 21 extends in a serpentine or meandering fashion and has a plurality of straight sections 24 , which in the exemplary embodiment are arranged parallel to one another and perpendicular to the longitudinal axis and at a close distance. Each two adjacent straight sections 24 are connected in accordance with FIG. 9 by sections 25 bent by 180 ° in such a way that there is an uninterrupted flow path from an inlet 26 to an outlet 27 . In particular Figs. 8 and 10 show, there is each passage 22 consists of two at the side edges of two parallel plates 23 extended and holding them at a distance, in the longitudinal direction of the heat exchanger block 20 extending strips 28 and arranged between the two plates 23 disks 29 of conventional construction. The passages 22 are therefore open in FIGS . 8 and 9 at the right and left ends, respectively. The arrangement is such that the passages 21 and 22 alternate in the heat exchanger block 20 , that is to say that the tubes (passages 21 ) are covered on both sides with plates 23 and these are kept apart by the strips 68 to form the passages 21 . According to this scheme, three passages 21 and four passages 22 are formed in FIGS. 8 to 10. In addition, between each of two plates 23 , between which the tubes forming the passages 21 are arranged, end strips 30 running parallel to the straight sections 24 and an end plate 31 each are provided at the upper and lower ends.

The various parts of the heat exchanger block 20 , like that of the Wärmetau cutter block 3, are preferably made of aluminum, in particular aluminum clad with a solder, and are first stacked in a manner known per se and then soldered to one another.

According to Figs. 1 to 3, the heat exchanger blocks 3 and 20 one above the other and firmly joined together, for. B. soldered. The passages 5 are where the air enters them ( Fig. 7) with a laterally attached and over the height of the heat exchanger block 3 extending collection box 33 connected liquid-tight, which is provided with an inlet opening having an inlet flange 34 . In contrast, the passages 5 are at their right ends, which are open in FIGS. 1 and 2, by means of a collecting or deflecting box 35 , which extends across the width and height of both the heat exchanger block 3 and the heat exchanger block 20 , with the likewise open right ends of the passages 22 ( FIG . 10) of the heat exchanger block 20 liquid-tight manner. Furthermore, the passages 4 are of the heat exchanger block 3, where the air in entering (Fig. 6), connected in liquid-tight with a stretched over the height of the heat exchanger block 3 collection box 36 having a inlet opening inlet flange 37 is provided. In contrast, the passages 4 open at their open in Fig. 1 and 2 left end keitstight in another, over the height and width of the heat exchanger block 3 extending collection box 38 , which is provided with an outlet opening A laßflansch 39 . This is covered by the inlet flange 34 in FIG. 1 and is therefore only visible in FIG. 2. Finally, the open ends in FIG. 9 of the passages 22 are provided with a liquid-tight header box 40 which extends over the width and height of the heat exchanger block 20 , the corresponding FIG. 2 has an extension 41 projecting to the side, which has an outlet opening having connecting flange 42 is provided, wherein the flow direction is parallel to that of a lassflansches 34 , while its inlet opening is opposite to the outlet opening of the outlet flange 42 .

The only schematically shown in Fig. 2 and 10 inputs and outputs 26, 27 of the passages 21 are summarized according to FIGS . 3 and 4 each by a tubular construction. Since a total of three passages 21 are provided in accordance with FIGS. 8 to 10, the three resulting outlets 27 are guided in the manner shown in FIGS. 3 and 4 through curved intermediate sections 43 to a flange 44 with a common outlet opening, which is via a curved tube 45 is provided liquid-tight with a connecting nipple 46 . The inputs 26 are correspondingly connected to a connecting nip 47 ( FIG. 1), which is not visible in FIG. 3, because this arrangement comprises the parts 43 to 46 corresponding part.

The heat exchanger device described, consisting of two firmly connected heat exchangers 1 and 2 , forms a compact, space-saving unit which, as a whole, can above all be assigned to a refrigeration dryer with which conventional compressed air systems are equipped, as will be explained briefly below. This has the particular advantage that the two heat exchangers 1 and 2 have essentially the same width and length and can be combined to form a common block.

Compressed air is supplied from a compressor, which is preferably provided with an aftercooler. B. is at a temperature of about 35-55 ° C. This compressed air is first fed to the collecting box 33 by means of the inlet flange 34 and flows from there in the direction of an arrow line 49 (FIGS . 2 and 7) through the passages 5 of the air / air heat exchanger 1 into the collecting and deflecting box 35 . From there, the compressed air enters the refrigerant / air heat exchanger 2 ( FIG. 1) and then flows through its passages 22 in the opposite direction ( FIG. 10 and arrow line 50 in FIG. 9). At the same time, the refrigerant is guided in the direction of the arrows shown in FIG. 9 through the passages 21 and thereby relaxed, due to the long running time caused by the straight and curved pipe sections 24, 25 ( FIG. 9) in the refrigerant / air heat exchanger 2 Despite its comparatively short overall length, a high degree of effectiveness with regard to the desired cooling of the compressed air is achieved. Otherwise, the refrigerant is conducted in a manner known per se in a refrigerant circuit, it being fed to the connection nipple 47 and discharged at the connection nipple 46 ( FIGS. 1, 3 and 5).

The compressed air cooled to the dew point (e.g. approx. 2-3 ° C) flows after the passage through the passages 22 into the collecting box 40 ( FIG. 1), is deflected laterally in this and enters its lateral extension 41 ( Fig. 2) and the outlet flange 42 again. The compressed air is then fed to a water separator 51 , as is shown schematically in FIG. 2. The completely dried compressed air emerging from this is finally fed back to the air / air heat exchanger 1 via the inlet flange 37 ( FIG. 2) and the collecting tank 36 , so that they passages 4 in the direction of an arrow line 52 in FIGS . 2 and 6 can happen. In this case, the compressed air in interaction with the warm compressed air passing through the passages 5 is warmed up to approximately room temperature before it reaches the collecting tank 38 ( FIG. 2) and is supplied to the tap for the compressed air via the outlet flange 39 . Depending on the required output of the two heat exchangers 1 and 2 , the number of their passages 4 and 5 or 21 and 22 can in principle be increased as desired by stacking a corresponding number of further plates or tubes without the dimensions increasing in height and change the width of the heat exchanger device.

An even more compact and less space-consuming heat exchanger device, which is particularly suitable for smaller outputs, results from FIGS. 11 to 17 . It contains an air / air heat exchanger 56 and a refrigerant / air heat exchanger 57 . In contrast to FIGS. 1 to 10, the two heat exchangers 56, 57 are not superimposed on one another, but are arranged next to one another and connected to one another to form an integral structural unit. For this purpose, both heat exchangers 56 and 57 are produced from a coherent heat exchanger block 58 , which in its right part in FIGS. 15, 16 and 18 has a section 59 responsible for the heat exchange air / air and in its in FIGS. 15, 16 and 18 left section has a section 60 responsible for the heat exchange refrigerant / air. Both sections 59, 60 are formed by plates 61 , which extend over the entire width and length of the heat exchanger block 58 .

Here, a portion of the plates stretched 61 on the one hand arranged by extending perpendicular to the longitudinal direction, right on in Fig. 15 end of the heat exchanger block 58 strips 62 and on the other by longitudinally and to in Fig. 15, 16 and 18 left end extending to the Side edges of the plates 61 arranged strips 63 and 64 kept at a distance. This creates passages 65 between the plates 61 , which are open at the left end of the heat exchanger block 58 in FIG. 18. At the right end in FIG. 18, the lower strips 64 are somewhat shorter, so that a space 66 is created between their right ends and the strips 62 , through which air can enter laterally in the direction of the arrow shown. In addition, the usual slats 67 ( FIGS. 15 and 17) are arranged in the passages 65 , which are designed according to FIG. 18 in such a way that the air entering laterally is deflected along a line 68 ( FIG. 18).

The other part of the plates 61 is, according to FIGS. 15 and 16, in the part forming the section 59 by strips 69 which run parallel to the longitudinal direction, are arranged on the side edges of the plates 61 and extend to the right end of the heat exchanger block 58 in FIGS. 15 and 16 and 70 and a transversely extending, at the left end of the section 59 terminating strip 71 terminated. This creates a further passage 72 between two plates 61 , which is open at the right end of the heat exchanger block 58 in FIG. 16. On the side of the end bar 71 , the upper bar 69 in FIG. 16 is somewhat shorter, so that an intermediate space 73 is formed between the two, which is in comparison to the intermediate space 66 on the opposite side of the heat exchanger block 58 , so that air enters laterally and in Direction of the drawn line ( Fig. 16) can be deflected. The deflection is effected analogously to FIG. 18, preferably with appropriately designed slats 74 .

In section 60 , on the other hand, the same plates 61 are kept at a distance by a serpentine or meandering passage 76 which has straight and curved sections 77, 78 and is constructed and arranged essentially in the same way as passages 21 according to FIGS. 8 to 10 . The passage 76 extends from the end bar 71 to an end bar 79 arranged at the left end of the heat exchanger block 58 in FIG. 17.

Otherwise, the arrangement is such that the passages 72 and 76 are arranged in a central part of the heat exchanger block 58 , to each of which a passage 65 ( FIG. 15) connects up and down.

An inlet 81 and an outlet 82 ( FIG. 16) of the passage 76 are each provided with a connecting nipple 84 , 85 according to FIGS. 11 to 14 and analogously to FIGS. 1 to 4 via curved pipe sections 83 , of which only in FIG. 13 the connection nipple 85 is visible. Furthermore, 65 with a collecting tank 86 and an inlet port having inlet flange or inlet nipple 87 fluid-tightly connected the right in Fig. 15, 16 and 18, ends of the passages, while the left in Fig. 15, 16 and 18, ends of the passages 65 with a Collection box 88 are connected in a liquid-tight manner, similar to the collection box 40 according to FIGS. 1 and 2, having a lateral extension 89 which is provided with an outlet opening 90 having a connecting flange 91 . Finally, the side opening of the passage 72 ( Fig. 16) is fluid-tightly connected to a collecting box 92 and an inlet flange or inlet nipple 93 having an inlet opening, while the right-hand end of the passage 72 in FIGS. 11 and 12 is connected to a collecting box 94 and one Outlet opening having outlet flange or outlet nipple 95 is liquid-tightly connected.

Analog to the embodiment according to FIGS. 1 to 10, the coming from the compressed air system is coming to z. B. about 35-55 ° C heated compressed air via the inlet flange 87 the Sam melkasten 86 supplied so that it flows through the passages 65 in the direction of an arrow line 96 ( Fig. 18). The compressed air is first cooled in the heat exchanger 56 to a temperature of approximately 20 ° C. by the cold compressed air coming from a water separator (not shown) and supplied in counterflow via the inlet flange 93 or the collecting tank 92 . On its way through the passages 65 , the compressed air is then gradually cooled to the dew point in the heat exchanger 57 , since it interacts with the refrigerant that flows through the passage 76 in the direction of the arrows ( FIG. 16). The compressed air is then fed via the collecting box 88 and the outlet flange 91 to the water separator and from there to the inlet flange 93 , so that it is again heated to approximately room temperature at the outlet nipple 95 , which serves as a tap for the compressed air.

As in the embodiment of FIGS. 1 to 10, the performance of the heat exchanger device can be changed in that the number of passages 65, 72 and 76 is changed accordingly while the length and width of the heat exchanger block 58 remain the same.

The invention is not limited to the exemplary embodiments described, which can be modified in many ways. For example, it is conceivable to assemble the passages 21 and 76 not from a continuous tube, but rather from a plurality of parallel tubes or from tube sections produced in a conventional plate construction, the sections corresponding to the straight portions being transverse to the longitudinal direction of the heat exchanger block 20 and 58, respectively extending strips and the sections corresponding to the curved sections are likewise formed by straight, but longitudinally extending sections, for example by the above-mentioned strips alternately ending in front of one or the other longitudinal edge of the respective heat exchanger cutter block, thereby freeing the refrigerant by 180 ° deflecting deflection sections.

It is also possible to use the connections shown (inlet and outlet flanges and -nipple) to other places if this should prove to be expedient. Finally, the flow directions indicated by arrows for the air and that Refrigerants are just examples.

Claims (11)

1. Heat exchanger device for refrigeration dryers on compressed air systems, consisting of an air / air heat exchanger and a refrigerant / air heat exchanger, characterized in that the air / air heat exchanger ( 1, 56 ) from a plate heat exchanger and the refrigerant / air Heat exchanger ( 2, 57 ) consists of a combined tube / plate heat exchanger. 2. Heat exchanger device according to claim 1, characterized in that the two heat exchangers ( 1, 2 ) lying one above the other and connected to one another with one another. 3. Heat exchanger device according to claim 1, characterized in that the two heat exchangers ( 56, 57 ) are arranged side by side and are connected to one another to form a structural unit. 4. Heat exchanger device according to one of claims 1 to 3, characterized in that the refrigerant / air heat exchanger ( 2, 57 ) from stacked plates ( 23, 61 ) and these spacing strips ( 28, 30 and 64th , 71, 79 ) and between the plates at least one passage ( 22, 65 ) provided with fins ( 29, 67 ) and a passage ( 20, 76 ) consisting of at least one pipe are formed. 5. Heat exchanger device according to claim 4, characterized in that the pipeline consists of a continuous, meandering pipe with parallel sections arranged in parallel ( 24, 77 ) and these connecting, by 180 ° deflecting sections ( 25, 78 ). 6. Heat exchanger device according to claim 5, characterized in that the straight sections ( 24, 77 ) are arranged perpendicular to the flow direction in which the fins ( 29, 67 ) on facing passages ( 22, 65 ). 7. Heat exchanger device according to one of claims 2 and 4 to 6, characterized in that the air / air heat exchanger ( 1 ) has two different types of passages ( 4, 5 ), one of which by a collection and deflection box ( 35 ) with the fins ( 29 ) having passages ( 22 ) of the refrigerant / air-heat exchanger ( 2 ) are connected. 8. Heat exchanger device according to one of claims 3 to 6, characterized in that the two heat exchangers ( 56, 57 ) have a common heat exchanger block ( 58 ). 9. Heat exchanger device according to claim 8, characterized in that the heat exchanger block ( 58 ) from stacked plates ( 61 ) and these spacing strips ( 62, 63, 64, 69, 70, 71, 79 ) is formed, wherein between at least two plates ( 61 ), a first passage ( 72 ) forming part of the air / air heat exchanger ( 56 ) and, in the longitudinal direction, a second passage ( 76 ) forming part of the refrigerant / air heat exchanger ( 57 ) are arranged . 10. Heat exchanger device according to claim 9, characterized in that little least one of these plates ( 61 ) with one formed by at least one further plate ( 61 ), substantially over the entire length of the heat exchanger block ( 58 ), third passage ( 65 ) interacts. 11. Heat exchanger device according to one of claims 1 to 10, characterized in that both heat exchangers ( 1, 2 and 56, 57 ) are made of aluminum.