WO1980000097A1

WO1980000097A1 - Thin wall frame and plate heat exchanger

Info

Publication number: WO1980000097A1
Application number: PCT/FR1979/000050
Authority: WO
Inventors: J Charraudeau
Original assignee: J Charraudeau
Priority date: 1978-06-14
Filing date: 1979-06-14
Publication date: 1980-01-24
Also published as: FR2428811A1; EP0016029A1

Abstract

Heat exchangers between two gases blown at different temperatures, of the plates (1) and peripheral modular elements (12, 14, 16) type. The plates (1) and the peripheral modular elements (12, 14, 16) are made of thin walls formed mechanically before being assembled by means of bolts (4) and nuts (5). These apparatuses are essentially intended for hot air ventilation and heating stations.

Description

Thin wall plate and frame heat exchangers

The invention relates to the constitution and production of plate heat exchangers between 2 gases blown each at a different temperature.

These devices can be classified into two categories according to their method of assembly.

In a first category, practically the only one existing, the adjacent exchange plates are assembled edge to edge on the part of the periphery of the plates where it is desired to contain the gas using the conventional techniques of folding, riveting, welding or gluing.

This constitutes a first block of stacked plates which are generally placed inside a parallelepipedal box for distributing the incoming and outgoing flows in order to better integrate the assembly into the ventilation networks.

In a second category to which the invention more precisely belongs, there are added, around the plates, intermediate frames constructed using at least 2 classes of modular elements placed end to end, mainly:

- elements open to the passage of gas entering or leaving between the plates

- closed elements

These frames assembled alternately with the exchange plates are then held in place using connections.

For questions of cost price and weight, the modular elements of the frames must be made of plastic or synthetic resin obtained by conventional techniques of injection molding, but the manufacturing molds are expensive.

The materials thus imposed having limited physical characteristics restrict the use of these exchangers to the field of low temperatures. The heat exchanger plates, although more simplified than in the case of the first technique, require an additional operation of drilling holes for receiving assembly rods.

The condensate collector, essential to constitute a complete exchanger does not exist in the case of this 2nd category of devices.

Finally, poor aerodynamics of the flow inputs and outputs handicaps these devices by increasing their pressure drops.

The devices assembling the components of the invention make it possible to avoid these drawbacks:

- the devices can operate at higher temperatures by the "metallic" choice of the material constituting the frames.

- the molds are replaced by less expensive forming and stamping tools.

- The plates of the invention of very simplified manufacturing eliminate the execution of welding as well as any drilling, bending or riveting operation around.

- the condensates, by the effect of the pressure in the exchanger, are evacuated through the frames and collected overall using receivers whose lateral mounting does not increase the length of the devices.

- one can reduce the pressure losses of the inputs and outputs by simple addition to each plate, of a profile.

The characteristics and advantages of the invention will emerge from the description below and from the appended drawings which show, by way of nonlimiting example, wine embodiment of the modular elements of the invention, and, examples of assembly, as well : - Figure I shows a "closed" element of the invention in top view, and Figure 2 shows the same element seen in section AA. - Figure 3 shows an "open" element of the invention seen from the side.

- Figure 4 shows the same element seen from above.

- Figure 5 is a partial view, in the plane-of a sealing plate, in the case of a frame corner with condensate collector, corner with one side mounted on closed element, and the other. side mounted on an open element.

- Figure 6 is a partial view along D perpendicular to the plane of the exchange plates to show the shape of these plates and their mode of superposition on each other.

- Figure 7 is a top view of a frame corner element.

- Figure 8 is a sectional view BB of the same corner

- Figure 9 is a partial section GG of exchangers passing through the axis of an assembly rod perpendicular to the planes of the frames.

- Figure I0 is a top view of the means of profiling the inputs and outputs of devices.

- Figure II is a view of open or closed elements in section CC.

- Figure I2 is a view 'of open elements in section EE.

- Figure I2 is a partial sectional view FF of a closed element, assembled by means of profiling this element.

- Figure I4 is an external view of a "cross" exchange device according to the invention, as well as the connection of the sheaths.

- Figure I5 is an external view of an exchange device "against current" according to the invention.

- Figures, I6 and I7 are perspective views of condensate receivers

The exchangers of the invention mainly consist of

- exchange plates I (fig. 5 and 6) - frames 2 surrounding the edges of the exchange plates to channel the gas flows (fig. I4 and I5).

- thick end plates 3 (fig. I4 and I5).

- rods 4 and nuts 5 (fig. 9). - a condensate receiver 6 (fig. 5).

The exchange plates I are simple planes in thin sheet metal, square or rectangular on which we have distributed (fig. 6) bosses 7 called "pillars" on either side of the plane of each plate, so that each pillar bump 7 of a plate joins a pillar bump 8 of one of the 2 adjacent plates: the main function of these bumps is therefore to achieve a constant spacing I0 between 2 consecutive plates.

A variant of exchange plates is constituted by the addition between the pillar bosses 7 of smaller bosses II which are therefore optional in the invention. Thus, with the aid of preliminary tests, thanks to the choice of the number and the height of the small bumps, it is possible to produce plates of the same size, but having different exchange efficiencies. In this way, the mechanical strength of the exchange plates is also increased.

The frames 2 consist of:

- I2 elements of the "open" type (fig. 4) to allow the entry or exit of gas flows between 2 plates I3 which follow each other (fig 9).

- I4 elements of the "closed" type (fig I) to wall the space between 2 exchange plates I5 which follow one another (fig 9) and thus channel the gas flow.

- closed elements I6 of the "corner" type (fig. I7) to allow the construction of the 4 angles of each frame.

The frames of the devices have 4 sides. Any one of the 4 sides is constructed using at least one open type element to enter the gas. The other 3 sides can be constructed using at least one other open element to take out the gas, the rest of the sides can be occupied by elements open or closed in a number defined by the choice of device construction.

The 2 types of closed and open elements are made of thin sheet metal formed in a U-shaped profile.

The closed and open elements and the corners are terminated by male ends I7 or female I8 in order to allow the frames to be produced by an end-to-end mounting (fig. 5) such as I9 or 20 of the elements and the corners therebetween.

The male end pieces thus have an external U profile which matches the inside of the U profile of the female end piece.

The locks of the sockets of the male end pieces in the female end pieces are locked using complementary bosses 2I and 22, that is to say that the external shape of the bosses 2I matches the internal shape of the larger bosses 22.

These bumps 2I and 22 are produced by cutting along an unclosed line, without removing material. They are made using a cylindrical punch whose face of the metal to be cut is a plane slightly inclined relative to the plane perpendicular to the axis of the cylinder in order to obtain a bump having a steep sinking more effective.

The closed and open elements have recesses 23 in the form of bowls pierced at the bottom to allow the passage of the assembly rods 4. Each element I2 or I4 thus comprises 2 adjacent bowls 23 and 24 by passing rods (fig. 9).

These led elements comprise asperities or bosses 25 which can be housed at the time of mounting in other asperities or bosses 26 complementary belonging to open or closed elements of adjacent frames such as 27 and 28 (fig. I5).

The open elements comprise at the bottom of U (FIG. 3) longitudinal openings 29, in the middle part of the element, to allow the passage of gases in the exchanger. The closed elements comprise (fig. I3) asperities or bosses 30 identical to the bosses 2I which make it possible to retain elements 3I provided (fig. I0) for profiling the inlets and the. gas outlet (fig. 9 - fig. I4).

The roughness such as 25 and 30 (fig. I) of the elements of the frames 39 and 40 placed (fig. I4 and I5) joined to the 2 plates terminated the 3 have been removed so as not to provide a means of passage of air between these 2 frames and their adjacent end plate.

The corners drawn in fig. 7 and 8 allow the reception of male end pieces of open or closed elements, as desired, and their maintenance at 90 ° in the same plane.

In order to allow the feasibility by stamping, the corners comprise a small bowl 32 of low pronf. Depth formed by the 2 walls 33 and 34 (fig. 8) of 2 small planes 35 connected to the plane 36 or bottom of the bowl, each small plane 35 forming an angle of I35 ° with the plane 36.

The profiled elements 3I (fig I3) have a V-shaped part. They are provided with straps 37 themselves pierced with small windows 38 and can be mounted in fig. 9 et.fig. I3 on each closed element.

One of the characteristics of the invention is the manufacture of frame elements from sheets using cutting techniques, folding punching and stamping which are part of the more general technique of mechanical forming.

Thus, for open and closed elements, we start from a continuous strip of flat sheet metal. This sheet, supposed to be wide, undergoes punching operations to make the different holes of the parts as well as stamping using dies to make the different flares, embossments or finally a cutting operation to achieve the desired lengths.

The forming of the U is then performed last by a stamping operation using an elongated die. The corners are also produced starting from flat sheet metal, by first drawing the shapes such as 22 before the other forming operations.

The 3I profiled elements are produced using cutting operations, then punching of the windows, and folding to obtain the final shape.

The mounting of a frame takes place by fitting the different types of elements (corners, open or closed elements) at their complementary end pieces so as to produce a four-sided frame as defined above.

The mounting of a plate is done on the periphery of a horizontal frame by placing the plate between the asperities 25 of the frame.

The placing of a frame on an adjacent frame having received a plate is done by superposition so that the housings such as 26 of one of the frames receive the complementary bosses such as 25 of the other frame.

The mounting of the devices, 2 examples of which are given in fig. I4 and fig. I5 is done by placing horizontally on a support a first thick plate 3 * then by placing the first frame 40 around the thick plate, then, successively placing, as said above, either a plate or a frame depending on the choice of device.

The device is completed by the installation of the 2nd thick plate, by the threading of rod 4 threaded and the tightening of nuts 5.

The profiles can be mounted from the outside after the devices have been completely assembled.

In the case of a large number of stacking of frames, the assembly is carried out barely for a part of frames comprised between the intermediate nuts such as 5 and such as 58 (fig. 9) _> the latter housed in the inside of frame elements no longer comprising a bowl 23 or, when the size allows, inside these same bowls 23. The nuts 58, in abutment at 59 on the last frame mounted, then allows the tightening along the rods 4 of the exchanger part considered.

The same boxes 58 are then reused as a means of tightening the next exchanger part which can be tightened using type 58 nuts and rod 4 extending the previous ones, or nuts 5, if the exchanger is completed.

The devices thus constructed can be made externally watertight by passing a coating on the 4 external faces perpendicular to the plane of plates with a brush or a spray gun. For this, the coating can be a silicone elastomer product capable of being more or less diluted, and resistant to 200 ° C.

Absolute tightness of the devices without leakage between the 2 gas flows on the one hand, and, without leakage between the flows and the outside on the other hand, can be obtained at the time of assembly by passing the coating over the lateral surfaces of the frames as well as around the edges of the plates.

The product, which has the property of becoming fairly quickly elastic, will ensure, thanks to the tightening pressure, the desired tightness.

The condensate receiver 6 has the function, when necessary, of collecting and evacuating the condensed water near the gas or cooled air outlets in the exchanger.

The condensate water can be discharged through orifices such as holes 4I (fig. 5) made either at the bottom of the corners surrounded by the condensate receiver in example I4 and the view in fig. 5 either at the bottom of U of closed elements (FIG. I) or open by means of holes 42 as in the mounting of the receiver 43 of FIG. I5.

In the case of evacuation through the corners of the invention, the receiver 6 (fig. I6) is very simplified. It can be an L-shaped profile 44 closed at the 2 ends by 2 triangular 45 planes which need only be welded to constitute the receiver. The collected water is out of the receiver through a metal sleeve 46 fixed to one of the 2 L-shaped sides

In the case of the lateral evacuation described above, the receiver (fig. I7) can be a profile 47 closed at both ends by covers 48.

The L-shaped receivers are mounted (fig. 5) by applying the edges of the L to the edges of the corners I6 of the assembled device and to the elements I2 or I4 fitted in these corners. The fixing is carried out using self-tapping screws 49 passing through the receiver through holes 50 and screwed onto holes previously drilled in the elements after assembly of the devices.

To obtain the watertightness of the receivers 6, care is taken to produce, for example using the silicone elastomer, continuous strips 5I or seals surrounding the inner circumference resting on the walls of the device at the time attaching a receiver.

The connection of the devices to the sheaths 52 can be done (fig. 15) by means of self-tapping screws 53 and. gasket 54 in the same way as for the condensate receivers.

The various holes 50 for fixing the receivers as well as the holes for receiving the self-tapping screws are preferably drilled only in frames not exposed to the production of condensate so as not to make it necessary to carry out a watertight seal at level of these fasteners due to the presence of condensation water.

We can use the condensate receivers as "sprinklers" of the exchange plates in order to practice a summary cleaning of these

For this, it suffices to mount at least "two other condensate receivers such as 55 and 56, then called" sprinklers ", in the upper part of the apparatus (fig. I5) and at least two other condensate receivers in the lower part, simply called water receptors such as 57 and 43 in such a way: - that at least one of the water sprinklers 55, which brings the irrigation water through the nozzles. either in communication with one of the gases via orifices such as 4I, while at least one other sprinkler 56 will be in communication with the other gas via other orifices.

- That at least one of the water receptors such as 57 intended for discharging the cleaning or sprinkling water is in communication with one of the gases by means of orifices such as 4l, while at least another water receiver such as 43 will be in communication with the other gas.

Another possible function of the sprinklers combined with the water receivers is to allow, by sprinkling the plates, sprinkling with a section of air or gas, and therefore at least summary humidification of the gases.

The sprinkler or humidification means can be improved by means of sprinklers installed in the lateral periphery of the frames in place of the holes for supplying sprinkling water and for humidifying the plates.

The advantage of installing the exchangers of the invention is present whenever there are two independent flows of gas blown at different temperatures and duct networks. This is the case of buildings or dwellings provided with forced air, as well as each time that one wishes to exchange calories from one gas for the benefit of another, in particular within the framework of energy savings.

Claims

I - Heat exchangers of the type consisting of successive stacks tightened with the aid of assembly members, exchange plates, and, placed at the periphery of the segment plates provided with openings and closed segments characterized in that that the segments and the exchange plates are obtained from the forming of thin plates.

2 - Heat exchangers according to claim I characterized in that at the 4 corners, the devices are constructed with truncated corner elements obtained from thin plates mechanically formed.

3 - Heat exchangers according to claim I characterized in that the exchange plates of the devices are planar quadrilaterals on which are distributed pillar bumps optionally coupled to pressure drop protuberances, the number and size of which are chosen for devices of the same size.

4 - Heat exchangers according to claim I characterized in that a longitudinal condensate receiver is mounted on one of the outer faces of the devices, perpendicular to the surfaces of the exchange plates.

5 - Heat exchangers according to claim I characterized in that additional V-shaped elements are added against the closed segments as profiles of the inputs and outputs of the devices.

6 - Heat exchangers according to claim I characterized in that a means for watering the plates is coupled to at least one means for receiving the coolant and in that these means are mounted on the external surfaces of the "devices, perpendicularly at the edges of the exchange plates.

7 - Receivers of condensates and coolant according to claims 4 and 6 characterized in that they consist of thin profiled plates closed at the ends, surrounding orifices.

8 - Watering means according to claim 6 characterized in that it consists of thin profiled plates, closed at the end, has at least one connection for supplying liquid and surrounds watering orifices.

9 - Watering means according to claim 6 characterized in that the means comprises sprinklers.

I0 - Heat exchangers according to claim I characterized in that the open and closed elements are formed mechanically according to a U-shaped profile.

II - Heat exchangers according to claim I characterized in that the assembly members are axes comprising at least one intermediate bolt with two end bolts.

I2 - Heat exchangers according to claim I characterized in that the open and closed elements are crossed by the assembly members by means of adjacent bowls pierced at the bottom.

I3 - Heat exchangers according to claim I characterized in that the open and closed elements include complementary bosses formed mechanically.