ITTO951023A1 - HEAT EXCHANGE AND / OR MATERIAL DEVICE - Google Patents

Abstract

A heat and / or fluid exchanger for fluids is described comprising a plurality of flat plates (1, 13) and a plurality of spacer means (6, 6.R; 22, 22.R), wherein these flat plates (1, 13) define, together with these spacer means (6, 6.R; 22, 22.R), one or more primary heat and / or material exchange chambers for the transit of a primary fluid, and these flat plates (1, 13) also define, together with these spacer means (6, 6.R; 22, 22.R), one or more secondary chambers for heat and / or material exchange for the transit of a secondary fluid. The primary chambers are in communication with each other and with the outside through a plurality of primary passages (IP, UP), and are intercalated with the secondary chambers, which are in communication with each other and with the outside through a plurality of secondary passages (IS, US). The characteristic of the exchanger according to the invention consists in the fact that at least one of these primary and / or secondary chambers comprises, as spacer means, two or more flat perforated plates (6, 6.R) each equipped with crossing openings (11) staggered to each other, so that the overlapping of these flat perforated plates gives rise to the formation of contact areas (11a) and crossing gates (11b), where the contact areas (11a) ensure thermal and mechanical continuity between the perforated flat plates (6, 6.R) and the passage openings (11b) communicate with each other at least some of the empty spaces that the crossing openings (11) create inside each perforated flat plate.

Description

Description of the industrial invention entitled:

"DEVICE FOR THE EXCHANGE OF HEAT AND / OR MATTER"

SUMMARY

A heat and / or material exchanger for fluids is described comprising a plurality of flat plates (1,13) and a plurality of spacer means (6,6.R; 22.22.R), where such flat plates (1,13) together with these spacer means (6,6.R; 22.22.R) define one or more primary heat and / or material exchange chambers for the transit of a primary fluid, and these flat plates (1,13) also define , together with these spacer means (6,6.R; 22.22.R), one or more secondary heat and / or material exchange chambers for the transit of a secondary fluid. The primary chambers are in communication with each other and with the outside through a plurality of primary passages (IP, UP), and are intercalated with the secondary chambers, which are in communication with each other and with the outside through a plurality of secondary passages (IS , US). The characteristic of the exchanger according to the invention consists in the fact that at least one of these primary and / or secondary chambers comprises, as spacer means, two or more perforated flat plates (6,6.R) each equipped with crossing openings (11) staggered between them, so that the overlapping of these perforated flat sheets gives rise to the formation of contact areas (11a) and crossing openings 11 b), where the contact areas (11a) ensure thermal and mechanical continuity between the perforated flat plates (6.6.R) and the crossing openings (11b) connect at least some of the empty spaces that the crossing openings (11) create inside each perforated flat plate.

DESCRIPTION

The present invention refers to a device for the exchange of heat and / or matter between substances in the liquid state, or in the vapor state, or in the gaseous state.

Plate heat exchangers are known; in their most widespread and consolidated version, these exchangers consist of metal plates, packed together in such a way as to define a certain number of parallel cavities.

Two fluids, which can be called primary and secondary, are made to pass through these cavities, between which a thermal exchange takes place; if the primary fluid flows in the cavities of even number, the secondary fluid flows in those of odd number, so that in each cavity one of the two fluids can exchange heat with the other through both plates that delimit the cavity itself. suitably confine each of the two fluids in their respective cavities and act as a spacer between one flat plate and the next.

Some of the aforementioned plates have holes in suitable positions, generally at the corners, through which the fluids that must be distributed in the cavities pass; the presence or absence of passage holes in at least some of the plates allows, according to known techniques, to arrange all the cavities crossed by the same fluid in parallel with each other, or to create paths consisting of packages of parallel cavities, but arranged in series with each other .

The plates through which the heat exchange takes place generally have a corrugated surface, since a series of parallel channels arranged in a herringbone pattern is formed on it by drawing; the slabs are assembled together, placing a straight one, an inverted one, and so on, so that the aforementioned channels of one slab are crossed with respect to those of the next slab; the presence of these channels improves the heat exchange, both because it increases the effective exchange surface, and above all because it increases the turbulence of the fluids, which are forced to follow a sinuous path between the channels.

A further purpose of the aforementioned channels is to allow contact between two successive plates, in small, closely spaced and regularly distributed areas, so that any pressure differences, even significant ones, between the two fluids can be supported by the plates without deformation; all the efforts are thus discharged on two terminal plates, closing the packet of plates, tightened by tie rods.

Plate heat exchangers are also known in which the aforementioned plates constituting the cavities are smooth; in these exchangers metal meshes are provided which substantially fill the cavity, without thereby preventing the fluids from flowing through the intertwining of the meshes of the mesh, so as to allow both the necessary turbulence and the mechanical and thermal contact between a plate flat and the next; for the rest, these exchangers do not differ substantially from the previous ones.

Finally, heat exchangers are known in which, by flaring the edges of each flat sheet by deep drawing, it is not necessary to use gaskets, since the seal can in this case be guaranteed by brazing, after having inserted each flat sheet with flared edges into the next.

Among the main advantages of plate heat exchangers is the possibility of creating very large exchange surfaces, albeit with very small dimensions, and the extreme simplicity with which series-parallel paths of various types, even very complex, can be obtained. simply alternating in the composition of the exchanger a few types of plates according to a suitable sequence.

Plate heat exchangers of the type using rubber gaskets have drawbacks, such as the difficulty of assembly in a totally automatic way and insufficient reliability in the case of use with toxic or corrosive liquids, especially if at high pressure. However, the welded versions also have limitations, since the coupling between the flared edges of the sheets is usually not sufficiently precise to allow the use of brazing alloys which guarantee the highest mechanical and chemical resistance; the latter in fact require particularly precise couplings between the pieces to be joined; therefore important uses such as ammonia refrigeration systems (both absorption and mechanical compression), are practically precluded to plate heat exchangers.

In general, the object of the present invention is to solve the above-mentioned problems of known types of devices and to indicate a device for the exchange of heat and / or matter which is efficient, simple and compact to manufacture, low cost and of use. particularly versatile.

In this, a first object of the present invention is to indicate a device for the exchange of heat and / or matter which can be made by means of modular, substantially flat elements, obtainable with simple mechanical processes.

second purpose of the invention is to indicate a device for the exchange of heat and / or matter that can be obtained with a minimum assortment of said modular elements, used repetitively and in different quantities depending on the case, so that its automatic modularity is extremely simple.

A third object of the invention is to indicate a device for the exchange of heat and / or matter which is compact and of reduced dimensions, with the same capacity, compared to known devices. A fourth object of the invention is to indicate a device for the exchange of heat and / or matter in which the formation of the gravitational films can be obtained in a simple and economical way.

These objects are achieved according to the present invention through a device for the exchange of heat and / or matter incorporating the characteristics of the attached claims, which form an integral part of the present description.

Further objects and advantages of the present invention will become clear from the detailed description that follows and from the attached drawings, provided purely by way of non-limiting example, which illustrate:

- Figs. 1 to 8 show components and assemblies suitable for constructing a heat and / or material exchanger according to the present invention;

- Figs. 9 to 18 represent components and assemblies of a device for the exchange of heat and compact matter according to the present invention.

In the aforementioned figures, where the parts which do not concern the description of the invention have been omitted, all the elements are shown in a vertical position.

Fig. 1 shows a generic flat plate for separating two successive cavities of a plate exchanger according to the invention; this plate, indicated as a whole with 1, has:

- a first passage, indicated by IP, delimited by a passage hole 2, for the transit of a primary fluid to be distributed in the cavities forming part of a primary circuit of the exchanger,

- a second passage, indicated by US, delimited by a passage hole 3, for the transit of a secondary fluid to be collected from the cavities forming part of a secondary circuit of the exchanger,

- a third passage, indicated by UP, delimited by a passage hole 4, for the transit of the aforementioned primary fluid to be collected from the cavities forming part of the primary circuit of the exchanger,

- a fourth passage, indicated by IS, delimited by a passage hole 5, for the transit of the aforementioned secondary fluid to be distributed in the cavities forming part of the secondary circuit of the exchanger.

In Fig. 2 a generic perforated flat plate is shown, having the function of spacing and supporting the plates of Fig. 2, as well as distributing and providing turbulence of the fluids.

As can be seen, this perforated plate, indicated with 6, has the same passages already defined in Fig. 1, marked with the same references IP, US, UP and IS, respectively defined by passage holes 7, 8, 9 and 10. The plate 6 also has an array of through holes, indicated with 11, arranged in a regular manner substantially over its entire surface; the array of through holes 11 is suitably interrupted near the through holes 7 and 9, while it intersects the through holes 8 and 10.

In Fig. 3, 6.R indicates a perforated flat plate identical to that of Fig. 2, but rotated in a circular direction by 180 °; the references IP, US, UP and IS identify the same passages as already defined with reference to Fig. 1, which however are now delimited, due to the rotation of the plate, respectively by the passage holes 9, 10, 7 and 8; the aforementioned row of through holes 11 is also visible.

Fig. 4 shows, in axonometry, the packing criterion of the plates of Figs. 1, 2 and 3, in order to realize a generic portion of a plate exchanger according to the invention. In this Fig. 4, the perforated flat plate 6 of Fig. 2, the perforated flat plate 6.R of Fig.3 and the separating flat plate 1 of Fig. 1 are shown.

In Fig. 5 a generic portion of a heat and / or material exchanger according to the invention is frontally shown; as can be seen, a perforated flat plate 6 is superimposed on a perforated flat plate 6.R so that the arrays of crossing holes 11, relative to both said plates 6 and 6.R, can define crossing paths, some of which they are indicated with 12; in the specific case of Fig. 6, the crossing paths 12 relate to a fluid coming from the passage IS and directed to the passage US.

Fig. 6 shows in greater detail some of the innumerable paths 12, defined by the holes 11 of the perforated flat plates 6 and 6.R, superimposed on each other; in this Fig.

6, with 11. A indicates one of the contact areas between the flat perforated plates 6 and 6.R, while with 11.B one of the crossing openings is indicated, which are obtained by virtue of the offset position of the arrays of holes crossing 11 made on perforated flat slabs 6 and 6.R.

As is clear in Fig. 6, the contact areas 11.A ensure mechanical and thermal continuity to the plates 6 and 6.R, while the crossing openings 11.B put in communication with each other some of the empty spaces that the crossing holes 11 realize inside each of the perforated flat plates 6 and 6.R. In a preferred embodiment of the device according to the invention, practically all the empty spaces made by the holes 11 inside the plates 6 and 6.R are put into communication with each other through the crossing gates lb.

In order to obtain a heat and / or material exchanger according to the invention, the plates illustrated above are then packed together so as to define a certain number of parallel cavities.

For this purpose, Fig. 7 shows laterally, in a generic section A - A of Fig. 5, the sequence of cavities obtainable from the alternating composition of a flat separation plate 1 of Fig. 1, of a perforated flat plate 6 of Fig. 2, of a perforated flat plate 6.R of Fig. 3, of a further separating flat plate 1, and so on. The figure also shows the arrays of through holes 11 and the crossing openings 11.B.

Fig. 8 is similar to Fig. 7, but in this case the first and third cavities (from the left) are each made by means of two perforated plates 6 and two perforated plates 6.R; Fig.8 therefore clarifies how each cavity of the heat and / or material exchange device according to the invention can actually consist of an unspecified number of plates, even different from cavity to cavity.

The device according to the invention, the constructive parts of which have been indicated in Figures 1-8, operates in the manner described below.

As said, the perforated flat plate 6.R of Fig. 3 is, in practice, constituted by the perforated flat plate 6 of Fig. 2 rotated in a circular direction by 180 ° on the plane (ie around an axis perpendicular to the plate itself); by making the row of through holes 11 in said flat perforated plate 6, in a suitable non-symmetrical position with respect to the center of the plate itself, and then overlapping the perforated plates 6 and 6R so as to make the axes of the holes delimiting the passages coincide IP, US, UP and IS, said arrays of through holes 11 overlap staggered with each other, as evident in Fig. 5, so as to create the crossing openings 11.B shown in Fig. 6. Between the two plates 6 and 6.R, however, large contact areas remain 11. A; by virtue of the presence of said contact areas 11. A, both peripheral and internal to the arrays of crossing holes 11, the plates 6 and 6.R can be solidly joined by gluing, brazing or other known techniques, to obtain a structure mechanically resistant and thermally conductive.

The assembly process can be continued indefinitely, as schematized in Fig. 4, alternating flat perforated plates 6 and 6.R and placing at the beginning and end of the package consisting of said perforated flat plates 6 and 6.R two flat plates of separation 1 of Fig. 1; in this way it is possible to obtain cavities in which, as shown in Fig. 5, a fluid (eg the secondary fluid) can freely circulate from the passage IS to the passage US, according to the innumerable crossing paths 12. This fluid does not however, it can in no way escape outside, nor mix with the primary fluid passing through the IP and UP passages.

If the cavity whose composition has just been described is alternated with another in which the perforated flat sheets 6 and 6.R are arranged overturned by 180 °, regardless of the horizontal or vertical axis (thus obtaining a mirror-like figure with respect to that of Fig. 5), then in this further cavity it will be the primary fluid that can freely circulate from the IP passage to the UP passage, without being able in any way neither to escape outside nor to mix with the secondary fluid passing through the IS and US passages.

The generic flat separation plate 1 shown in Fig. 1 can also be considered as the outermost plate of a heat exchanger; in this case, nozzles can be fixed in correspondence with the passage holes 2, 3, 4 and 5 (for example identical to the nozzles indicated with 51 in Fig. 19); through these nozzles, a primary fluid can be introduced into the exchanger through the IP passage and extracted through the UP passage; similarly, a secondary fluid can be introduced through the passage IS and withdrawn through the passage US.

It can be seen from Figs. 1,3,4 and 5 that said passages IP, UP, IS and US continue through all plates 1, 6 and 6.R without for this reason that the aforementioned primary and secondary fluids, as already demonstrated, can come into material contact between They; on the contrary, through the flat separation plates 1, a thermal contact is obtained between the fluids flowing in parallel and in countercurrent; as it can be understood, more complex circuits consisting of groups of cavities arranged in parallel with each other and in series with respect to other groups of cavities can be easily obtained, according to known techniques (for example, using separation plates similar to 1, in which however there are no one or more of the passage holes 2, 3, 4, 5)

The perforated flat plates 6 and 6.R can be of any thickness, even very thin, since there are only practical limits to the external dimensions of the device and to the thickness of the perforated flat plates themselves, as well as to the quantity of said plates in a single cavity. The flat separation plates 1 must have an adequate thickness to withstand the pressure differences that may exist between the two fluids between which the heat exchange takes place, and between these and the external environment.

As highlighted in Figs. 7 and 8, it is possible to obtain cavities composed of a variable number of perforated flat plates 6 and 6.R, since the heat transmission between the two fluids is ensured by the fact that all the perforated flat plates 6 and 6.R arranged in the same cavity they have thermal bridges formed by the contact areas 11.A.

Finally, it should be noted that it is not at all necessary that the perforated flat plates 6.R be obtainable only by rotation of 180 ° from the perforated flat plates 6; this is in fact a considerable production advantage, but for the purposes of the operation of the exchanger, the plate 6.R could be suitably different (for example by design of the row of through holes 11 and / or by the thickness) from the flat perforated plate 6. Furthermore, for reasons of fluid-thermodynamics, it is generally appropriate that the arrays of through holes 11 are designed according to the type of fluid that passes through them: therefore, in general, in the same exchanger the cavities in which the primary fluid flows could be made up of flat perforated plates 6 and 6.R different, according to the design of the array of through holes 11, thickness and quantity, from the corresponding perforated plates 6 and 6.R relating to the secondary fluid. It may also be advantageous for the array of through holes 11 to be suitably constituted, for thermo-fluid dynamics reasons, by holes having a different shape and distributed unevenly.

The only conditions required are that, by superimposing a perforated flat plate 6 on a perforated flat plate 6.R, the already said crossing openings 11.B and the already said contact areas 11.A.

Both the flat plates 1 and the perforated flat plates 6 can be made of metal or ceramic material of the heat-conducting type.

The circulation cavity of the primary and secondary fluids can be sealed by brazing plates 1 and 6 (if made of metal) or by using sealants or elastomeric gaskets. An alternative technique consists in covering the surface of the slabs with a deposit, for example of polytetrafluoroethylene, and then sealing the substance deposited on the slabs by sintering.

The device according to the present invention just described with reference to Figures 1-8 can be immediately applied as a heat exchanger, between a primary fluid, distributed in the primary chambers (cavity of odd number) through the passages IP and UP and a secondary fluid, distributed in the secondary chambers (even-numbered cavities) through the IS and US passages. The heat exchange between the primary fluid and the secondary fluid is carried out through the flat separation plates 1.

The use of the perforated flat plates 6 and 6.R as spacer elements between the separation plates 1, to obtain the primary chambers and the secondary chambers, has, as we have seen, numerous advantages with respect to known devices, and in patrticular:

1) the turbulence of the fluids is enhanced thanks to the crossing gates 11.B and the efficiency of the heat exchange is therefore improved;

2) the entire device can be built with a few modular elements (separation plates 1 and perforated flat plates 6 suitably oriented);

3) the assembly of the device can be carried out in an automated way;

4) the desired thickness of both the primary and secondary chambers is achieved simply by superimposing the appropriate number of plates 6;

5) the thermodynamic processes can be influenced in the desired way through simple constructive parameters of the plates 6, such as number, diameter and pitch of the holes 11.

The possibility of using the device described with reference to Figures 1-8 as a material exchanger for fluids is also evident for those skilled in the art.

A particularly advantageous heat and material exchanger device according to the invention will also be described with reference to Figures 9-18. This device will be described with reference, for greater clarity, to a distillation and rectification device; however, it is clear, as will be seen below, that the inventive idea is also applicable to other devices for the exchange of matter (with or without heat exchange).

As will be seen, also for the purposes of obtaining the distilling device according to the invention, plates of suitable shape are packaged together in such a way as to define a certain number of parallel cavities, in which a liquid mixture to be distilled can pass, a refrigerant fluid, a heating fluid, a vapor mixture to be rectified.

Fig. 9 shows a generic flat end or separation plate, indicated with 13, of the compact distillation and rectification device according to the invention; this plate 13 has:

- a passage IL, delimited by a hole 14, for the transit of a rich liquid mixture to be distilled, to be distributed in cavities which form distillation chambers;

- a passage IR, delimited by a hole 15, for the transit of a refrigerant fluid to be distributed in cavities for a refrigerant fluid,

- a UV passage, delimited by a hole 16, for the transit of a distilled vapor, to be collected from the aforementioned cavities of the distillation chambers,

- a passage UR, delimited by a hole 17, for the transit of the aforementioned refrigerant fluid, to be collected from the cavities of the refrigerant fluid,

- a passage IV, delimited by a hole 18, for the transit of a very rich mixture in the state of vapor to be rectified, to be distributed in the cavities of the distillation chambers,

- a passage UE, delimited by a hole 19, for the transit of a heating fluid, to be collected from the cavities for a heating fluid,

- a passage UL, delimited by a hole 20, for the transit of a lean liquid mixture, to be collected from the cavities of the distillation chambers,

- a passage IE, delimited by a hole 21, for the transit of the aforementioned heating fluid, to be distributed in the cavities of the heating fluid.

Figs. 10 and 11 show flat perforated plates 22 and 22.R, hereinafter referred to as the "rectification side", to be used for the formation of the cavities in which a mixture to be distilled flows; as will be seen, by packing two or more flat plates 22 and 22. R "rectification side", the distillation and rectification cavities are obtained in which the mixture to be distilled and / or rectified circulates, as will become apparent in the following of this description.

The plate 22 of Fig. 10 shows, indicated with the same letters IL, IR, UV, UR, IV, UE, UL and IE, the same passages already highlighted in Fig. 9, respectively delimited by passage holes 23, 24, 25, 26, 27, 28, 29 and 30; an array of through holes 31 are also visible, arranged in a regular manner substantially over the entire surface of the plate 22; the row of through holes 31 is suitably interrupted near the through holes 24, 26, 28 and 30, while it intersects the through holes 23, 25, 27 and 29 (in particular, of the row of through holes 31, they are the holes 31. A and 31. B, intersecting the passage hole 23) are highlighted; finally, 32 indicates a boiling area of the mixture to be distilled, an adiabatic rectification area 33 and a rectification area 34 with refrigeration; the reason for this denomination will become clear later.

In Fig. 11, with 22. R, a flat perforated plate "grinding side" is shown identical to that indicated with 22 in Fig. 10, which however has undergone a rotation of 180 ° with respect to the latter; the letters IL, ER, UV, UR, IV, UE, UL and IE identify the same passages already defined in Fig. 10, which are now delimited, due to the rotation of the plate, respectively by the passage holes 27, 28, 29, 30, 23, 24, 25 and 26; also indicated is the array of through holes 31 (of which in particular the holes 31.C and 31.D, intersecting the passage hole 27, are highlighted), as well as the aforementioned boiling zones 32, of adiabatic rectification 33 and grinding with refrigeration 34.

Figs. 12 and 13 show flat perforated plates "exchanger side", indicated with 35 and 35.R, to be used for making the cavities in which the heating or cooling fluids flow for the mixture to be distilled; as will be seen, the "exchanger side" perforated plates 35 and 35.R are the elements capable of forming, by packing, of two or more specimens, the heat exchange cavities in which the fluids intended to cause the partial boiling of the liquid mixture circulate to be distilled or the partial condensation of the vapor of the mixture to be rectified.

The perforated flat plate 35 "exchanger side" of Fig. 12 has, indicated with the same letters IL, IR, UV, UR, IV, UE, UL and IE, the same passages already defined in Fig. 10, respectively delimited by holes passing 36, 37, 38, 39, 40, 41, 42 and 43; furthermore, at the positions of the boiling zones 32, adiabatic rectification 33 and rectification with refrigeration 34 identified in Figs. 10 and 11, three rows of holes are indicated, namely:

- a heating fluid crossing array, indicated by 44 (suitably interrupted near the passage holes 40 and 42, while it intersects the passage holes 41 and 43),

- a neutral array, indicated by 45 (not intersecting any of the passage holes, but connected to the outside through vent openings 47),

- a cooling fluid crossing array 46 (suitably interrupted near the passage holes 36 and 38, while it intersects the passage holes 37 and 39).

In Fig. 13, with 35. R, a perforated flat plate is shown identical to that indicated with 35 in Fig. 12, but rotated by 180 ° with respect to this; the letters IL, IR, UV, UR, IV, UE, UL and IE identify the same passages already defined in Fig. 9, which in this case are delimited, due to the rotation of the plate, respectively by the passage holes 40, 41 , 42, 43, 36, 37, 38 and 39; the figure also indicates the same rows of holes, already identified in Fig. 12, as well as the vent openings 47.

Fig. 14 shows, in axonometry, the packing criterion of the plates of Figs. 9, 10, 11, 12, and 13, to make a generic portion of the distillation and rectification device, comprising the cavity in which the mixture to be distilled circulates and the cavity in which the heating or cooling fluids of said mixture circulate.

In this Fig. 14, a perforated flat plate "grinding side" 22, a perforated flat plate "grinding side" 22 are shown. R, a flat separation plate 13, a perforated flat plate "exchanger side" 35, a flat plate perforated "exchanger side" 35. R and again a flat separation plate 13; the usual passages IL, IR, UV, UR, IV, UE, UL and IE are also indicated, in the same position for each of said plates.

In Fig. 15 a generic portion of the distillation and rectification device made according to the invention is shown frontally; there is a perforated "grinding side" perforated flat plate 22 superimposed on a "grinding side" perforated flat plate 22. R, as well as the boiling zones 32, adiabatic rectification 33 and rectification with refrigeration 34; the passages IL, IR, UV, UR, IV, UE, UL and IE are also indicated, having omitted to mark the other elements whose identification is now clear.

Fig. 16 shows a perforated flat plate "exchanger side" 35 of Fig. 12, superimposed on a perforated flat plate "exchanger side" 35. R of Fig. 13 are also highlighted

- the array of heating fluid passage holes 44, which is in a position corresponding to the aforementioned boiling zones 32 of FiG. 15,

- the neutral hole array 45, which is in a position corresponding to the adiabatic rectification zones 33 of FiG. 15,

- the array of cooling fluid passage holes 46, which is in a position corresponding to the rectification areas with cooling 34 of FiG. 15,

- the vent openings 47,

- the passages IL, IR, UV, UR, IV, UE, UL and IE.

Fig. 17 shows, according to a section made along the axis A - A of Fig. 15, a cavity provided for the circulation of the fluid to be distilled and another cavity provided for the circulation of heating or cooling fluids; Fig. 17. A represents an enlarged detail of Fig. 18.

In these figures, therefore, a possible sequence of perforated plates "on the grinding side" 22 and 22.R are represented, constituting a distillation and rectification cavity 48, and a possible sequence of perforated plates "exchanger side" 35 and 35. R, constituting a heat exchange cavity 49; between the two aforementioned sequences there is a flat separation plate 13, between the distillation cavity 48 and the heat exchange cavity 49.

Fig. 17 also indicates, in the distillation cavity 48, the boiling zone 32 of the mixture to be distilled, the adiabatic rectification zone 33, the rectification zone with refrigeration 34; in the heat exchange cavity 49, on the other hand, the array of holes for passing through the heating fluid 44, the array of neutral holes 45 and the array of through holes for cooling fluid 46 are indicated.

Fig. 18 shows in axonometry a possible embodiment of a compact distillation and rectification device, indicated with 50, according to the present invention.

Said device 50 comprises an unspecified number of distillation cavities, intercalated with an equal number of heat exchange cavities, separated as previously described by separation plates; Fig. 18 also shows the several times cited passages IL, IR, UV, UR, IV, UE, UL and IE, delimited by nozzles 51; the arrows 52 indicate the direction of the flows entering or exiting the aforementioned nozzles 51.

The operating modes and the advantages of the heat and / or compact material exchange device according to the invention are now described in detail, illustrating some preferred but not exclusive embodiments and limiting itself to the case of the separation of two rather than more substances from one. single liquid mixture, in the case of a distillation and rectification device.

The "grinding side" perforated flat plates 22 and 22. R of Figs. 10 and 11 are, as mentioned, the elements suitable for constituting, by packing two or more specimens, the distillation and rectification cavities 48 of Fig. 17, in which the mixture to be distilled and / or rectified circulates; the perforated plates "exchanger side" 35 and 35. R of Figs. 12 and 13, on the other hand, are the elements suitable for forming, by packing two or more specimens, the heat exchange cavities 49 of Fig. 17, in which the fluids intended to cause the partial boiling of the liquid mixture to be distilled and / or the partial condensation of the vapor of the mixture to be rectified, or in which both said fluids circulate, without them being able to come into thermal or material contact with each other. The distillation and rectification cavities 48 and heat exchange 49 are separated by the flat separation plates 13 of Fig. 9; the first or last, or both of the flat separation plates 13 can be provided with the nozzles 51 of Fig. 18.

Some embodiments of the device according to the invention and other devices obtainable using the same inventive concept will now be illustrated. Each device, unless otherwise specified, consists of an indeterminate quantity of distillation and rectification cavities 48 intercalated with heat exchange cavities 49, in the manner described above.

COMPLETE DISTILLATION AND GRINDING DEVICE

In all the distillation and rectification cavities 48, shown frontally in Fig. 15, through the passage IL enters a rich liquid mixture to be distilled, through the UV passage the distilled vapor exits, through the passage UL the lean liquid mixture comes out; in this distillation and rectification process the passage IV is therefore not used and therefore said passage is closed with respect to the outside, for example in correspondence with the relative mouthpiece 51 of Fig. 18.

At the same time, in all the heat exchange cavities 49, shown frontally in Fig. 16, a refrigerant fluid enters the passage IR and exits the passage UR, while a heating fluid enters the passage IE and exits the passage UE.

The device is divided, from bottom to top, into the following three areas:

I- Boiling and distillation zone.

In the boiling zone 32 of Fig. 15 the boiling and partial vaporization of the liquid mixture coming from II takes place by the heating fluid circulating in the array of heating fluid crossing holes 44 of Fig. 16; as a consequence of this, the liquid residue depleted of the more volatile substance leaves the passage UL, while the vaporized part rises in the adiabatic rectification zone 33 to meet, in counter-current, the rich liquid mixture which enters from passage IL. It should be noted that the liquid mixture coming from IL drips by gravity alone through a very bumpy path, created by the series of crossing gates (11. B, Fig. 7) interrupted by the contact areas (11.A, Fig. 6) and moreover hindered by the steam generated by boiling; therefore, by suitably designing the "grinding side" perforated flat plates 22 and 22.R, the descent can be sufficiently slow to allow a sufficiently depleted mixture to reach the passage UL.

II - Adiabatic rectification area.

The distillation and rectification cavities 48 can be constructed of sufficient width and with a sufficient number of flat "rectification side" perforated plates 22 and 22. R, so that the liquid mixture coming from the passage IL cannot flood said cavities, but must sliding along the surfaces of the aforementioned "grinding side" perforated flat plates 22 and 22.R; the possible tendency of said rich liquid mixture to collect in rivulets, instead of wetting said surfaces, is continually opposed by the fact that said mixture which descends is continually forced to change path in correspondence with the contact areas 11.A and the crossing openings 11.B; in this way a rectification is obtained according to the principle of gravitational films, avoiding however the drawbacks of the known art.

Alternatively, if this is considered advantageous for the specific process of use, there is nothing to prevent the arrays of through holes 31 of the "grinding side" perforated flat plates 22 and 22.R from having holes in this area small enough to slow down the descent. of the liquid mixture, forcing the vapor to bubble through it.

Therefore, in the adiabatic rectification zone 33 of Fig. 15 the liquid which descends is preheated at the expense of the steam which rises; in this way the equilibrium concentrations of the substances in the mixtures are shifted: therefore, the liquid mixture, when heated, will release part of the more volatile substance to the vapor, while the vapor, cooling down, will release part of the less volatile substance to the liquid; the process is therefore "adiabatic" in the sense that there are heat exchanges between the liquid and vapor phases, but not with fluids outside the distillation and rectification cavities 48.

In correspondence with the adiabatic rectification areas 33, the heat exchange cavities 49 have arrays of neutral holes 45, not traversed by any fluid, the purpose of which is to ensure structural continuity of the whole device; said arrays of neutral holes 45 are connected externally by means of vent openings 47, which are suitable for avoiding pressure increases or for disposing of gases which may be produced during the brazing phase of the device.

III - Rectification area with refrigeration.

When the steam has passed the passage IL, it enters the rectification zone with refrigeration 34, where a further cooling of the steam takes place by a colder fluid circulating in the heat exchange cavity 49; by virtue of this latter cooling of the vapor, an almost total condensation of the less volatile residues, still present in the vapor, occurs, while the more volatile substance, practically pure, leaves the UV passage; the purification process is facilitated by the fact that, also in this rectification zone with refrigeration 34, the condensate which descends is obliged to intimate contact with the rising steam, for the same reasons valid for the adiabatic rectification zone 33; moreover, the accidents of the path capture any condensate droplets carried by the steam. It has been pointed out that the distillation and rectification cavities 48 must be sufficiently large not to be flooded by the rich liquid mixture coming from the passage IL; taking this need into account, if the passage IL were intersected by the array of through holes 31 both in the upper part of its perimeter and in the lower part, it would be possible that all the rich liquid mixture coming from the outside of the distillation and rectification device it was drained from the first distillation and rectification cavities 48 encountered, flooding them, while the following ones would not be fed; for this reason, and with reference to Figs.

10, 11 and 15, it is advisable for the array of through holes 31 to intersect the passage IL only in correspondence with the holes 31. A, 31.B, 31.C and 31.D, which are all placed in correspondence with the upper half of the perimeter of the passage IL; in this way the rich liquid mixture distributed by the passage IL, before descending into the distillation and rectification cavity 48, must flood the lower half of the aforementioned passage IL and therefore overflow along the entire length of said passage IL, without being able to preferentially feed the first 48 distillation and rectification cavities encountered.

It has also been said that in the distillation and rectification process just discussed, step IV is not used; in reality it can be used in particular cases, in which the process, in addition to requiring relatively cold and extremely pure steam of the most volatile substance, also requires hotter and more easily condensable steam at low pressure, or in any case also requires steam relatively little rich; in this case, said steam can be tapped from passage IV, coming directly from the boiling zones 32.

It should be noted, with regard to steam tapping from passage IV, that said passage IV, in correspondence with the distillation and rectification cavities 48, is delimited by the same holes that delimit passage IL; therefore, as evident in Fig. 16, it communicates with the distillation and rectification cavities 48 only from the lower part, which constitutes a valid obstacle to the entry, in the passage IV itself, of the rich liquid mixture dripping from the passage IL. Finally, it should be noted that, since no thermal exchanges with the outside are foreseen (nor pressures to be endured, except for the flat separation plates 13 at the ends), the perforated flat plates '' grinding side "22 and 22. R can also not be made of material with particular thermal conductivity or mechanical resistance; in particular it is not necessary that said plates be metallic, but of any other material suitable for the purpose such as particular types of ceramics or synthetic material.

It is evident that the construction criteria described can be used even only partially, to build less complex devices than the one just described, without departing from the inventive idea.

By way of example, forms of the device according to the invention are now illustrated which use only some of the functions, processes or elements just described.

COMPLETE GRINDING COLUMN

In this case, reference is made to Fig. 15, which remains unchanged, except that the passages IE and UE are not used and therefore must be closed with respect to the outside. From passage IV a very rich mixture in the vapor state enters the device, coming from a suitable steam generator external to the device itself; from the passage IL a rich liquid mixture enters as previously to be distilled; the lean liquid mixture and the rectified vapor exit respectively from the UL and UV passages as previously.

Since the device does not need to boil the mixture to be distilled, only the cooling fluid circulates in the heat exchange cavities 49, through the array of through holes 46, while the remaining rows of through holes have only a structural function.

ADIABATIC GRINDING COLUMN

Reference is still made to Fig. 15, which remains unchanged, except that the passages IE, UE, IR and UR are not used and are therefore closed with respect to the outside.

In this case, neither cooling fluid nor heating fluid are required and the rectification device according to the invention can be composed exclusively of a first separation flat plate 13, of an indeterminate quantity of perforated flat plates "on the grinding side" 22 and 22.R, alternating between them, and by a second flat separation plate 13.

DISTILLATION DEVICE OR STEAM GENERATOR

In all the distillation and rectification cavities 48, shown frontally in Fig. 15, through the passage IL enters a rich liquid mixture to be distilled, through the UV passage the distilled vapor exits, through the passage UL the lean liquid mixture comes out; in this distillation and rectification process, step IV is not used and is therefore closed from the outside.

The boiling zones 32 extend from the level of the lower passages UL and UE up to the height of the upper passages IR and UV.

In this application, in place of the cavities 49, there are heat exchange cavities made with the same type of perforated plates "grinding side" 22 and 22.R, however overturned by 180 ° around the horizontal axis, with respect to how they are shown in Fig. 15; in this way the heating fluid can enter the passage IR and exit the passage UE.

ABSORBER FOR ABSORPTION REFRIGERATING SYSTEMS

In the cavities 48, which in this case become the absorption cavity, the lean mixture is allowed to enter from the passage IL and the vapor to be absorbed from the UV passage, while the rich mixture exits from the passage UL.

As regards the heat exchange cavities, from which the heat generated by the absorption process must be removed, they can be made exactly as described for the "Distillation device or steam generator" just treated.

OTHER APPLICATIONS

It is evident that many other variants and applications are possible for the heat and / or compact material exchange device according to the invention.

For example, distillation or rectification columns can be created in which steam tapping occurs in several areas, for example to separate several substances from each other, as well as more than two heat exchange zones with more than two heat transfer fluids in the case of which, in complex systems, it is useful to make the best use of fluids available at various temperatures in various stages of the cycle.

Such heat recoveries, theoretically obtainable even now, are generally ignored due to the excessive cost of the quantity of exchangers required; with the present invention, the simplicity with which several heat exchange zones can be obtained (by making further passage holes) from a single compact device makes the cost increase irrelevant.

Intermediate fluid heat exchangers can be made when, for safety reasons, it is not advisable for the two fluids exchanging heat to directly touch the opposite faces of the same wall. In this case, using the known technique of the so-called heat pipes, a first fluid circulating in the cavities 44 can for example transferring heat to a second fluid circulating in the cavities 46 by means of an intermediate fluid which is continuously boiling and condensing in the cavities 48.

Finally, the intimate contact that is obtained between the liquid phase which descends and the vapor phase which rises, by virtue of the large surfaces that form the perforated flat plates of one of the types described, makes the present invention particularly interesting for the construction of chemical reactors.

It is evident that, as already explained above, the "grinding side" perforated flat plates 22. R can be obtained from the "grinding side" perforated flat plates 22 by simple rotation of the latter by 180 ° with respect to their center, as well as the already said "grinding side" perforated flat plates 22.R may originate from a completely different design with respect to that of the already said "grinding side" perforated flat plates 22; obviously the same condition applies to the "exchanger side" perforated flat plates 35 and 35. R, provided that the conditions are met that, in the overlapping of all the aforementioned plates, the arrays of crossing holes 31, 44, 45 and 46 create the contact areas 11. A and the U.B crossing gates and that the continuity of the passages is ensured (IL, UL, IV, UV, IE, UE, IR, UR).

It is also evident that all the arrays of through holes just mentioned must have holes of suitable dimensions, spacing and distribution for the individual processes and fluids and that said arrays of holes may also consist of a series of holes with a diameter and / or pitch. different within the same slab or different slabs.

However, it is important to point out that different fluid-thermodynamic needs, such as heat exchange efficiency or acceptable pressure drop, can be answered not only by varying, from case to case, the design of the arrays of crossing holes 33, 44 or 46, but also maintaining the design of the perforated flat plates 22 or 35 unchanged for many applications, and varying the quantity and / or thickness constituting each cavity 48 or 49.

Therefore, all the distillation and rectification devices described are substantially achievable with the sole use of the three elements:

- perforated flat plate "grinding side" 22 ",

- flat perforated plate "exchanger side" 35 e

- flat separation plate 13

arranged according to the appropriate position and suitably intercalated with each other and all equipped with the eight passages IL, IR, UV, UR, IV, UE, UL and IE, suitably used or intercepted. Finally, it is evident, as shown in some examples, that the constructive simplicity of the components of the complete distillation and rectification device according to the invention greatly extends the freedom of choice of materials and surface treatments necessary for the components themselves, compared to what possible with reference to the current state of the art.

Claims (22)

CLAIMS 1. Heat and / or material exchanger for fluids comprising a plurality of flat plates (1; 13) and a plurality of spacer means (6,6.R; 22.22.R), said flat plates (1; 13) defining, together with said spacer means (6,6.R; 22,22. R), one or more primary chambers for heat-to-material exchange for the transit of a primary fluid, said flat plates (1; 13) further defining, together with said spacer means (6,6. R; 22.22.R), one or more secondary heat and / or material exchange chambers for the transit of a secondary fluid, called primary chambers, communicating with each other and with the outside through a plurality of primary passages (IP.UP), and said secondary chambers, communicating with each other and with the outside through a plurality of secondary passages (IS.US), being interspersed, characterized in that at least one of said chambers comprises, as spacer means, two or more perforated flat plates (6,6.R; 22.22.R), said perforated flat plates (6,6.R; 22,22. R) essen do each equipped with through openings (11; 31) offset from each other, in such a way that the overlapping of said perforated flat plates gives rise to the formation of contact areas (11. A) and crossing openings (11.B), called contact areas (11.A ) ensuring thermal and mechanical continuity between said flat perforated plates (6,6.R; 22.22.R), said crossing openings (ll.B) by connecting at least some of the empty spaces that said crossing openings (11; 31) create inside each of said flat perforated plates (6,6.R; 22.22.R). 2. Heat and / or material exchanger, according to claim 1, characterized in that said crossing openings (11.B) put in communication with each other most of the empty spaces that said crossing openings (11; 31) they produce inside each of said flat perforated plates (6.6.R; 22.22.R). 3. Heat and / or material exchanger, according to claim 1 or 2, characterized in that said crossing openings comprise arrays of holes (11; 31), interrupted near the edges of said plates (6,6.R; 31). 4. Heat and / or material exchanger, according to claim 3, characterized in that said plates (6,6.R; 22.22.R) each have at least four main holes (7,8,9,10) for making of said primary (IP, UP) and secondary (IS.US) passages, two (8,10) of said main holes being intersected by said crossing holes (11; 31) in order to connect said primary or secondary passages together through said crossing gates (11.B). 5. Heat and / or material exchanger, according to the preceding claim, characterized in that said main holes (7,8,9,10) are made near the edges of said plates (6,6.R; 22.22.R ). 6. Heat and / or material exchanger, according to claim 4, characterized in that said main holes intersected (8,10) by said crossing holes (11; 31) are made at different heights on said perforated flat plates (6 , 6.R; 22.22.R). 7. Heat and / or material exchanger, according to claim 1, characterized in that said flat perforated plates (6,6.R) comprise plates of the first type (6; 22) and plates of the second type (6.R; 22.R), said second type plates (6.R; 22. R) being obtained starting from said first type plates (6; 22) by rotation of 180 ° on their plane. 8. Heat and / or material exchanger, according to claim 1, characterized in that each primary chamber is separated from a secondary chamber by means of one of said flat plates (1; 13), said flat plates (1; 13) each presenting at least one hole (2, 3, 4, 5) to secure or interrupt said primary (IP, UP) and / or secondary (IS, US) passages in order to provide the desired types of connection between said chambers and with the outside. 9. Heat and / or material exchanger, according to claim 1, characterized in that at least some of said primary chambers and at least some of said secondary chambers comprise said perforated flat plates (6,6.R; 22,22.R) . 10. Heat and / or material exchanger, according to the preceding claim, characterized in that said perforated flat plates (6,6.R; 22.22.R) used in said secondary chambers can be obtained from perforated flat plates (6,6. R; 22.22.R) used in said primary chambers by overturning by 180 ° with respect to an axis of said plates. 11. Heat and / or material exchanger, according to claim 1, characterized in that said crossing openings (11; 31) comprise holes of variable shape, size and interval along the extension of the same plate (6.6.R; 22.22 .R). 12. Heat and / or material exchanger, according to claim 3, characterized in that said arrays of (11; 31) are interrupted in such a way as to cancel some of said crossing openings (11.B) in determined areas, at in order to prevent certain passages of the circulating fluid. 13. Heat and / or material exchanger, according to claim 1, characterized in that a plurality of said primary and / or secondary chambers each comprise a plurality of said perforated flat plates (6,6.R; 22.22.R), being the number of flat perforated plates included in one of said primary or secondary chambers different from the number of flat perforated plates included in another of said primary or secondary chambers. 14. Heat and / or material exchanger, according to claims 7 and 10, characterized in that it is made by stacking an appropriate number of said first type perforated plates (6; 22) suitably arranged in a straight or 180 rotated position ° on the plane, or overturned by 180 ° with respect to an axis, or rotated by 180 ° on the surface and overturned by 180 ° with respect to an axis, being inserted between said plates, in suitable intermediate positions and at the ends, of the flat plates (1 ; 13). 15. Heat and / or material exchanger, according to the preceding claim, characterized in that said perforated plates (6; 22) and said separation plates (1; 13) are made of metal. 16. Heat and / or material exchanger, according to the preceding claim, characterized in that the sealing of said chambers is achieved by brazing said plates (1,6; 13,22) 17. Heat and / or material exchanger, according to claim 14, characterized in that said perforated plates (6; 22) and said separation plates (1; 13) are made of ceramic material. 18. Heat and / or material exchanger, according to claim 14, 15 or 17, characterized in that said chambers are sealed by means of elastomeric sealants or gaskets. 19. Heat and / or material exchanger, according to claim 14, 15, 17 or 18, characterized in that the surfaces of said plates (1,6; .13,22) are covered, at least partially by a substance deposited therein , in particular from polytetrafluoroethylene. 20. Heat and / or material exchanger, according to the preceding claim, characterized in that the sealing of said chambers is achieved by sintering said deposited substance. 21. Heat and / or material exchanger, according to one of the preceding claims, characterized in that one or more of said perforated flat plates (6; 22) and / or separation plates (1; 13) has a different thickness from the remaining perforated flat plates (6,22) and / or separation plates (1; 13). 22. Heat exchanger and / or material, as it results from the present description and the annexed drawings.