Heat medium distributor for an air inlet system including multiple heat exchangers

A heat medium distributor for an air inlet system having multiple heat exchangers includes a box-like housing, which is divided by a dividing wall into a first flow chamber, which is used as the forward collection pipe, and a second flow chamber, which is used as the return collection pipe. For each heat exchanger to be connected, a forward connection nozzle branches off the first flow chamber and for each heat exchanger to be connected, a return connection nozzle opens into the second flow chamber. The arrangement of the connection nozzles is such that all flow paths of the heat medium through the various heat exchangers and the distributor are of equal length. The heat medium distributor replaces traditional heat medium distributors which are produced by welding together individual pieces of pipe, and which are structurally relatively large and therefore expensive, and in general cannot be housed in the housing of the air inlet system.

The invention concerns a heat medium distributor for an air inlet system including multiple heat exchangers, with

a) a forward collection pipe for the heat medium, with a forward connection nozzle branching off it for each heat exchanger;

b) a return collection pipe for the heat medium, with a return connection nozzle opening into it for each heat exchanger, where

c) the forward and return connection nozzles are arranged so that the flow paths of the heat medium through the distributor are of equal length for all heat exchangers.

In many industrial processes, particularly painting, it is a requirement that the air which is brought into the treatment room should be conditioned, particularly heated. For this purpose, so-called air inlet systems, in which multiple heat exchangers are arranged in parallel to heat the air to be conditioned, are used. A heat medium distributor feeds heated heat medium, in most cases hot water, to the individual heat exchangers, and guides away the heat medium which has been cooled by passing through the heat exchanger.

Known heat medium distributors are produced by soldering or welding individual pieces of pipe to each other. This is associated with expensive manual work, which requires qualified personnel. Also, these known heat medium distributors are structurally relatively large, because all welds must be accessible. The consequence of this large construction is that the heat medium distributor is not normally fitted in the housing of the air inlet system, but must be placed on (not necessarily on top of) it. For this reason, they must be provided with expensive heat insulation.

The object of this invention is to create a heat medium distributor which is of the above-mentioned type, but can be produced more economically and requires less space.

According to the invention, this object is achieved in that

d) the heat medium distributor has a box-like housing, which is divided by a dividing wall into a first flow chamber, which is used as the forward collection pipe, and a second flow chamber, which is used as the return collection pipe.

According to the invention, therefore, the heat medium distributor itself no longer consists of pieces of pipe, but essentially is in the form of a box-like housing, which—remotely from the air inlet system on which it is to be fitted—can be produced by largely automatic methods. In this way, the quality of the joins is improved at lower cost. With equally large or even larger flow paths, the box-like housing can be housed in a smaller space than the traditional heat medium distributors. With greater flow cross-sections, the flow rate and flow resistance are reduced, resulting in lower operating costs. The heat medium distributor according to the invention can be fitted in the housing of the air inlet system, and then tested, in the factory, and then transported together with the air inlet system to the end customer, so that the installation time on the end customer's premises is reduced.

Specially preferred is an embodiment of the invention in which the housing is divided by two dividing walls into three flow chambers, of which the first is used as the forward collection pipe and the second and third communicate with each other in one end area, and are used jointly as the return collection pipe. The heat medium which returns from the heat exchangers thus flows through the distributor in one direction, then makes a 180° turn and flows back in the opposite direction. In this way, the connections via which the hot heat medium is fed to the heat medium distributor, and the cooled heat medium is fed away from it, are provided in the same end area of the housing.

It is useful if the housing is put together out of commercially available semi-finished products. As such semi-finished products, flat plates or sheet metal, curved sheet metal or similar can be considered. These must be cut to shape if necessary and then joined to each other. This also reduces considerably the costs which are associated with the production of the heat medium distributor according to the invention.

In particular, the housing can be welded together out of steel parts.

In an advantageous embodiment of the invention, all forward and return connection nozzles are arranged on the same side of the housing, running approximately parallel to the dividing wall. The forward or return connection nozzles pass through the flow chamber which is adjacent to the relevant side of the housing. This heat medium distributor can therefore be arranged, for instance, above the various heat exchangers in the housing of the air inlet system, and can be connected directly to the connections of the individual heat exchangers via its connection nozzles.

Alternatively, it is possible to arrange the forward and return connection nozzles on a side of the housing running approximately perpendicularly to the dividing wall, offset laterally against each other and thus opening directly into the corresponding flow chambers. In this embodiment, it is unnecessary for the connection nozzles to penetrate through a flow chamber, which however in some circumstances makes a somewhat more expensive arrangement of pipes outside the distributor necessary.

The requirement for precision of the welds during production of the heat medium distributor itself, and production and fitting of the heat exchangers, can be reduced if the forward and/or return connection nozzles of the heat medium distributor each include a flexible connector, e.g. a piece of hose. In this way, it is easily possible to compensate for positional divergences of the connection nozzles of the heat medium distributor relative to the connections of the heat exchangers.

As mentioned above, because of the small construction of the heat medium distributor according to the invention, in many cases it is possible to house the heat medium distributor within the housing of the air inlet system. In this case, the housing of the heat medium distributor itself no longer requires thermal insulation, resulting in another significant cost advantage.

The heat medium distributor which is shown in the drawings, and which as a whole has the reference symbol1, is used to feed heat medium, for instance hot water, to multiple heat exchangers. These heat exchangers, which are not shown in the drawings, are in an air inlet system such as is found, for instance, in painting plants, and there conditions, particularly heats, the inlet air for the spray cabin.

The heat medium distributor1has a box-shaped housing2, which essentially is produced from commercially available sheet metal semi-finished products. This housing2comprises a rectangular, flat top side2a, a correspondingly shaped rectangular, flat bottom side2b, two curved side walls2cand2dwhich are semicircular in cross-section, and two correspondingly shaped end walls2eand2f, which can be understood as rectangles with semicircular surface sections placed on their narrow sides.

The housing2is divided by two dividing walls3,4, which extend perpendicularly to the housing top and bottom sides2band are tightly joined to them, into a total of three flow chambers5,6,7.

As shown by, in particular,FIG. 2, the first dividing wall3begins on the left-hand end wall2einFIG. 2, on a line by which the long dimension of the end wall2eis divided in the ratio 1:2. This first dividing wall3runs via a relatively short section parallel to the side walls2cand2dof the housing2, and is then offset in parallel by a wall piece3a, which runs parallel to the end wall2e, by about a third of the width of the housing2, seen in the direction of the longitudinal extent of the end wall2e. Another dividing wall section3cis put on the dividing wall section3b, and now runs parallel again to the side walls2cand2dand as far as the right-hand end wall2fof the housing inFIG. 2, and is welded to it.

Between the lower side wall2binFIG. 2and the first dividing wall3, a first flow chamber5is formed in this way. This is somewhat widened in the area5awhich is adjacent to the left-hand end wall2e, compared with the other area5b.

The second dividing wall4is put on the dividing wall3at a certain distance from the dividing wall section3band parallel to it, with a section4awhich in turn extends by about a third of the longitudinal dimension of the end walls2eand2fin the direction of the upper side wall2cinFIG. 2. On this section4a, a dividing wall section4b, which runs parallel to the side walls2cand2dand ends at a certain distance from the right-hand side wall2finFIG. 2, is then put.

The internal space of the housing2, between the first dividing wall3and the upper side wall2cinFIG. 2, is thus divided by the second dividing wall4into two flow chambers6,7, which communicate with each other at the right-hand end of the housing2inFIG. 2. The third flow chamber7, which is adjacent to the upper side wall2cinFIG. 2, is widened in an area7abetween the section3bof the first dividing wall3and the section4aof the second dividing wall4b.

Into the widened area5aof the first flow chamber5, an inlet nozzle8, via which the hot heat medium can be brought into the first flow chamber5of the distributor1, opens from above, i.e. passing through the top side2aof the housing, approximately in the centre of the transverse dimension of the top side2aof the housing. Similarly, into the widened area7aof the third flow chamber7, a return flow nozzle9, via which the medium which has flowed through the distributor1and the heat exchangers can be guided away, opens from above, passing through the top side2aof the housing.

On the side wall2dof the housing2, at the bottom ofFIG. 2, at regular intervals forward connection nozzles10, which open into the first flow chamber5, are attached. Offset against these forward connection nozzles10in the longitudinal direction of the housing2, also at regular, identical intervals, on the lower side wall2dinFIG. 2, return connection nozzles11are provided. They pass through the first flow chamber5and open into the second flow chamber6. Each of these connection nozzles10,11includes, outside the housing2, a flexible piece of hose10aand11arespectively, which is used as a connecting piece, and a connecting flange10band11brespectively.

All parts of the distributor1preferably consist of steel, and are tightly welded at the places where they are joined to each other.

Because of its comparatively small dimensions, the distributor1described above can be fitted within the housing of the air inlet system, directly adjacent to the heat exchangers. This has the advantage that the distributor1, unlike the previously known distributors which were put together out of individual pieces of pipe, and had to be arranged outside the housing of the air inlet system, does not have to be insulated. When the distributor1is fitted, the inlet nozzle8is connected to the house-side forward pipe of the heat medium, the return flow nozzle9is connected to the house-side return pipe of the heat medium, the forward connection nozzles10are connected to the corresponding forward connections of the heat exchangers, and finally the return connection nozzles11are connected to the return connections of the individual heat exchangers. Because of the flexible hose pieces10a,11a, it is possible to compensate for certain dimensional divergences in the position of the connections of the heat exchangers, so that to this extent it is unnecessary to maintain high welding precision.

In the operation of the air inlet system, hot heat medium flows via the inlet nozzle8on the top side2aof the distributor1into the first flow chamber5. It is fed from there via the forward connection nozzles10in the lower side surface2dinFIG. 2to the various heat exchangers, where it partly gives up its heat to the air to be heated. From each heat exchanger, the cooled heat medium returns via a return connection nozzle11ato the distributor1, where it first flows through the first through-flow chamber6, then makes a 180° turn at the right-hand end of the housing inFIG. 2, flows through the third flow chamber7in the opposite direction, and is finally guided away via the return flow nozzle9on the top side2aof the housing2to the house-side return pipe.

The arrangement of forward and return connection nozzles10and11respectively, via which the individual heat exchangers are supplied, corresponds to the Tichelmann principle. This means that the path of the heat medium through the distributor1and heat exchangers is of equal length for each individual heat exchanger, so that all heat exchangers are supplied with heat medium in the same way.

The described distributor1can be in modular form. This means that at least in its central area it consists of identical sections, in each of which the three described flow chambers5,6,7are formed and which have a certain number of connection nozzles10,11for heat exchangers. However, the widened areas5a,7aof the flow chambers5,7, the inlet nozzle8and the return nozzle9in the top side2aof the housing, and the connection between the flow chambers6and7, are absent from these central sections of the distributor1.

In an embodiment of the invention (not shown in the drawings), the third flow chamber7is absent. The heat medium is therefore not fed back to near that part of the housing2in which the inflow takes place. The inlet nozzle8and return nozzle9in the top side of the housing2are therefore at opposite end areas of the housing2.

It may be possible to do without the hose pieces10a,11ain the inlet connection nozzles10and return connection nozzles11, if care is taken for high precision in the case of the welds of the distributor1and in the fitting of the heat exchangers. Such rigid connection nozzles10,11are obviously more economical.

In the case of the embodiment which is presented above on the basis of the drawings, all connection nozzles10,11for the heat registers are arranged on that side2dof the housing2which runs approximately parallel to the dividing wall3. This makes it necessary that the return connection nozzles11penetrate the flow chamber5so that they can open into the flow chamber6. These penetrations are avoided in an embodiment (not shown in the drawings), in which the connection nozzles10,11are arranged on a side of the housing2running approximately perpendicularly to the dividing wall, for instance on its bottom side2b. By a certain lateral displacement of the return connection nozzles11relative to the forward connection nozzles10, it is possible for all connection nozzles10,11to open directly into the correct flow chamber5,6in each case.