JPH09280786A - Chemical resistant heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a chemical resistant heat exchanger capable of being used in a wide temperature range from a low temperature up to a high temperature. SOLUTION: This heat exchanger is provided with a heat exchanger substrate 2, a chemical resistant coated layer 3, a side wall body 5 made of a chemical resistant material and an inlet/outlet opening, and a gasket constituted of a core material 21 having an approximately trapezoidal cross-sectional shape and a chemical resistant jacket surrounding the core material 21 from three directions is provided in a seal groove 10 and line protrusions 15, 16 are formed on a circumference of the jacket and an outer circumference 21a of the core material is made to get into contact with an outer side wall face 12 of the seal groove and a small clearance is provided between an inner side wall face 11 and the gasket 20. The core material is allowed to expand and contract in directions of the clearance in accordance with temperature fluctuation so that pressure on a tapered face of the core material is effectively applied on the protrusions to obtain sealing performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger or a liquid temperature controller, and more particularly to a chemical resistant seal structure thereof.

[0002]

2. Description of the Related Art The reaction rate of a chemical solution depends on temperature in most cases. Therefore, in order to accurately control the reaction of highly reactive chemical liquids, particularly precise liquid temperature control is required, but at the same time, these chemical liquids are often extremely corrosive.
As a temperature controller for this type of chemical liquid, for example, one as shown in FIG. 6 is used. (JP-A-4-359
795).

The liquid temperature controller 100 includes a pair of heat exchange substrates 10 made of a material having good heat conductivity such as aluminum, stainless steel, alumina or graphite.
1, 101 are arranged in a face-to-face relationship with a predetermined space therebetween, and the opposing surfaces 102 of these heat exchange substrates 101 are coated with a fluororesin in order to prevent the heat exchange substrates from being eroded. Form a chemical coating. A space between the pair of heat exchange substrates 101, 101 is liquid-tightly enclosed by interposing a side wall body 103 made of a chemical resistant material, for example, a fluororesin between the pair of heat exchange substrates. so,
The heat exchange chamber 104 is formed.

[0004] The side wall 103 is provided with an inlet 105 and an outlet 106 for a chemical solution. On the outer surface of the heat exchange substrate 101,
One side of the thermoelectric conversion element 107, ... is closely contacted so that heat can be transferred,
On the other side of the elements 107, ..., A heat radiator 108 having a flow passage 109 through which cooling water passes is provided in a plate-like block made of a material having good thermal conductivity in a close contact state so that heat can be exchanged. Into the heat exchange chamber 104, a chemical liquid, for example, a semiconductor etching liquid is introduced from the chemical liquid tank T by a pump P from an inlet 105, adjusted to a predetermined temperature, and then sent from the outlet 106 to the chemical liquid tank T again. To be

In such a heat exchange chamber 104, the heat exchange substrate 101 and the side wall body 10 are provided in order to prevent the pressurized chemical liquid from leaking.
As shown in the figure, a packing storage groove 110 is provided around the side wall body made of a chemical resistant material such as a fluororesin at the contact portion with 3 and the chemical resistant material ( For example, an O-ring made of fluororubber or the like is housed or used, or a ring-shaped sealing material having a structure in which the O-ring 111 is wrapped with a fluororesin cover ring 113 having a protrusion 112 is devised, and a There is a structure that maintains the liquid tightness of the heat exchange chamber by using a material intended to further improve the sealing performance by deforming the cross-sectional shape of the sealing material so that the projection 112 is brought into pressure contact with the substrate 101. It is used.

The chemical temperature controller having such a structure is
Generally, it is required to adjust the temperature of a highly toxic or corrosive chemical liquid such as hydrogen fluoride, nitric acid or sulfuric acid in a wide temperature range of 10 to 90 ° C., if necessary. Therefore, if liquid should leak, it is extremely dangerous, and it is necessary to allow for a sufficient safety factor for the allowable pressure.
When used for applications such as semiconductor manufacturing, it is necessary to prevent the chemical solution from being contaminated due to the elution and mixing of impurities from the wall surface of the heat exchange chamber and the seal portion.

This kind of chemical liquid temperature controller has a structure in which a side wall body made of a chemical resistant polymer such as fluororesin is firmly tightened by a bolt via a heat exchange substrate. When exposed to a high temperature under such a strong pressure, the side wall made of a substance undergoes deformation due to the creep phenomenon. Therefore, in the chemical temperature controller used even at a high temperature even once, deformation due to elongation at the molecular level of the resin that constitutes the side wall body, reduction of the tightening force of the bolt, and the like occur, and the low temperature range (for example, 10 When used at -30 ° C), the dimension of the side wall body in the thickness direction does not return to the original dimension, and the depth dimension of the packing accommodating groove 110 is slightly longer. Therefore, the pressure contact force of the packing with respect to the seal surface is relatively decreased, which is one of the causes of the decrease in the pressure resistance of the seal portion. Further, the lower the operating temperature is, the lower the rubber elasticity of the O-ring 111, which is the core material, is also a factor that accelerates the deterioration of the sealing property, and there is a risk of causing liquid leakage.

In order to avoid such a situation, as shown in FIG. 4, there is provided a device in which a circulation pump P, a chemical temperature controller 100, a filter F, and a chemical bath S constitute a circulation channel for the chemical. There is no other way than using two units, one as a temperature controller dedicated to high temperature chemicals and the other as a temperature controller dedicated to low temperature chemicals, depending on the operating temperature.
There was a heavy burden on equipment costs, installation space, and management costs.

[0009]

A first object of the present invention is to disclose a chemical resistant heat exchanger having a novel seal structure in which the pressure resistance does not change due to the temperature change of the passing chemical solution. . A second object of the present invention is to disclose a chemical resistant heat exchanger that can be used in a wide temperature range from low temperature to high temperature without limitation on the operating temperature.

[0010]

A first aspect of the present invention is to provide a pair of heat transfer substrates which are made of a material having good thermal conductivity and which are arranged to face each other with a predetermined space therebetween, and the pair of heat transfer substrates are opposed to each other. A chemical-resistant coating layer covering the surface and a heat-resistant substrate made of a chemical-resistant material and interposed between the pair of heat-conductive substrates to be pressed against the heat-conductive substrate through the chemical-resistant coating layer and exchange heat with the heat-conductive substrate. A series of seals including a side wall body surrounding the chamber and a fluid inlet / outlet for opening the heat exchange chamber to the outside, and a pressure contact portion of the side wall body with the chemical resistant coating layer surrounding the heat exchange chamber in a loop shape. In a chemical resistant heat exchanger in which a groove is provided and a gasket is housed in the seal groove to seal the heat exchange chamber, the gasket includes a loop-shaped core member made of a rubber elastic material and at least an outer peripheral surface of the core member. And a jacket made of a chemical resistant material covering the core material except A ridge is provided on each of the peripheral surfaces of the jacket, which face the bottom surface of the seal groove and the opening surface of the seal groove, and the core material is provided on the peripheral wall surface of the seal groove on the side remote from the heat exchange chamber. The chemical-resistant heat exchanger is characterized in that the outer peripheral surfaces of the two are in contact with each other.

Materials having good thermal conductivity include copper, aluminum or alloys thereof, metal oxides such as stainless steel and alumina, and non-metal materials such as graphite.
Those that can be easily molded are preferred. As for the property of the material, when a chemical resistant sheet (film) described below is used as the chemical resistant coating layer, it differs from the case where a chemical resistant coating is integrally formed by coating or vapor deposition on the surface of the heat transfer substrate. As long as it has the necessary rigidity, you can freely select it.

As the chemical resistant coating layer for covering the opposing surfaces of the pair of heat transfer boards, a chemical resistant thin film is integrally formed with the heat transfer board by coating a fluororesin or the like depending on the material of the heat transfer board. However, chemical resistant sheet (film)
May be adopted. The sheet and the heat transfer substrate can be bonded by using a method such as bonding, pressure contact by making the bonding surface a vacuum, or bonding via a semi-fluid such as heat conductive grease. The thickness of the sheet is preferably as thin as possible so long as the strength is maintained.

A fluororesin is suitable for the material of the sheet having chemical resistance and the chemical resistant material forming the side wall. Examples of the fluororesin include tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-perfluorovinyl ether copolymer (Teflon PFA ... registered trademark), polytetrafluoroethylene (PTFE), and the like. Is the moldability,
Although inferior to the former two, it is suitable because it has the best chemical resistance and heat resistance. The side wall body may be one whose outer surface is coated with the above-mentioned chemical resistant material, but is preferably made of a material itself having chemical resistance from the viewpoint of ease of manufacture and reliability.

As the loop-shaped rubber elastic material forming the core material of the gasket, in case of an accident such as damage to the chemically resistant jacket or the chemically resistant coating layer, fluorocarbon rubber or silicone rubber is used. It is preferable to use a chemical rubber, but even among fluororubbers, a fluorocarbon fluororubber having extremely small compression strain and excellent chemical resistance is most preferable.

In the heat exchanger defined in the above first aspect, the outer peripheral surface of the loop-shaped core member of the jacket type gasket which is not covered by the jacket is provided on the outer peripheral wall surface of the seal groove on the side remote from the heat exchanger. Since the gasket is mounted in the state of abutting or light pressure contact, when the temperature of the gasket rises, the outer peripheral surface of the core material expands to the outer peripheral wall surface side of the seal groove (in other words, the direction in which the diameter increases). (Expansion to) is not allowed, the deformation and increasing repulsive elastic force of the rubber material forming the core material acts only as a force to swell the jacket, and the pressure is concentrated on the ridges of the jacket, Delivers a strong sealing force. Therefore, in order to prevent the gasket from being unduly deformed, it is desirable to provide a slight gap between the gasket and the inner peripheral wall surface. With such a configuration, even if the operating temperature reciprocates from a low temperature range to a high temperature range, the sealing performance of the gasket is increased, so that no liquid leakage accident occurs.

A second aspect of the present invention is to cover a pair of heat transfer substrates which are made of a material having good thermal conductivity and which are arranged to face each other at a predetermined interval, and to cover the facing surfaces of the pair of heat transfer substrates. A chemical resistant coating layer and a chemical resistant material are interposed between the pair of heat transfer substrates and are pressed against the heat transfer substrate via the chemical resistant coating layer to surround a heat exchange chamber together with the heat transfer substrate. A side wall body; and a fluid inlet / outlet opening the heat exchange chamber to the outside.
A series of seal grooves that surround the heat exchange chamber in a loop shape are provided in a pressure contact portion with the chemical resistant coating layer, and a gasket is housed in the seal grooves to seal the heat exchange chamber. In the above-mentioned gasket, the gasket is made of a rubber elastic material and has a cross-sectional shape in which the thickness gradually decreases from the large diameter portion to the small diameter portion, and a chemical resistance that covers the core material except at least the outer peripheral surface of the core material. A jacket made of a flexible material, and a ridge is provided on each of the peripheral surfaces of the jacket that face the bottom surface of the seal groove and the opening surface of the seal groove. On the peripheral wall surface of the peripheral wall surface on the side remote from the heat exchange chamber, a gap is provided between the gasket and the peripheral wall surface on the side close to the heat exchange chamber while the outer peripheral surface of the core member abuts. Heat resistant to chemicals characterized by In the exchanger.

In the heat exchanger according to the second aspect, the cross-sectional shape of the core material is such that the core material peripheral surface facing the inner peripheral wall surface from the outer peripheral wall surface (the peripheral wall surface remote from the heat exchange chamber) of the seal groove. Since the distance between them is configured to be gradually reduced, the typical shape of the cross section of the loop-shaped core material is erected on the outer peripheral wall and becomes wedge-shaped or trapezoidal from the outer peripheral wall toward the inner peripheral wall. It has a protruding shape. However, it is sufficient that the slope of the trapezoidal slope has a very small slope of the order of several degrees. Alternatively, only one of the facing peripheral surfaces of the core material may be inclined.

In this chemical resistant heat exchanger, when the temperature of the corrosive chemical is adjusted in a high temperature range, the elasticity of the gasket is sufficiently exerted so that the ridges of the ridges and the bottom surface of the seal groove and the heat exchange substrate. It strongly presses against the chemical resistant layer and seals the chemical. Next, when this heat exchanger is used in a low temperature range, the rubber structure that constitutes the core material of the gasket is reduced in elasticity as the temperature drops, and the rubber structure shrinks while hardening and further reducing the compression strain. To do. Due to this contraction phenomenon, the diameter of the loop-shaped core material becomes small, and the core material slightly moves toward the inner peripheral wall surface in the seal groove,
At this time, the slope of the core material strongly presses the ridges of the jacket against the mating surface as if the wedge had been driven into the jacket, thus compensating for the decrease in sealing pressure due to creep deformation occurring in the side wall body, etc. As a result, this can be prevented.

Thus, the chemical liquid temperature controller incorporating the heat exchanger of the present invention can be used in a wide temperature range from a low temperature region to a high temperature region, and has a great saving effect on equipment cost, installation space, management cost and the like. .

[0020]

1 and 2 show an example of an embodiment of the present invention, showing a case where a heat exchanger is incorporated in a chemical liquid temperature controller. The chemical liquid temperature controller Y is composed of a chemical resistant heat exchanger 1, electronic refrigerators 80 and 80 using thermoelectric conversion elements (Peltier elements), and radiators 90 and 90. The heat exchanger 1 includes a pair of heat transfer substrates 2 and 2 made of a material having good heat conductivity such as aluminum or graphite which is corrosion-resistant with aluminum or alumite treatment or fluororesin coating, and the heat transfer substrates 2 and 2. In between, there is a side wall body 5 that is interposed via chemical resistant sheets 3 and 3 as a chemical resistant coating layer and constitutes a heat exchange chamber 4 together with the heat transfer substrates 2 and 2.

The chemical resistant sheets 3 and 3 are heat transfer substrates 2 and 2.
By being adhered to the entire opposing surfaces 2a, 2a, they are integrally bonded to the heat transfer substrate. As the chemical resistant sheet 3, a PTFE sheet is used as in the side wall body 5. The electronic refrigerator 8 is provided on the outer surfaces (non-opposing surfaces) of the heat transfer boards 2 and 2.
One side of 0, 80 (acting mainly as a cooling surface) is press-contacted so that heat can be transferred, and the other side of the electronic refrigerator is
Similarly, a heat dissipation block 91 made of a material having good heat conductivity is in contact with the heat transferable. A pair of cooling water conduits 92, 92, ... Are connected to the heat radiation blocks 91, 91, and the cooling water is passed through the heat radiation blocks to cool the heat radiation blocks. Further, the heat exchange chamber 4 is also provided with inlets and outlets 6a and 6b of the chemical liquid by a pair of chemical liquid conduits 6 and 6 penetrating the side wall body 5.

As shown in FIG. 2, the side wall body 5 is integrally formed of a high-purity PTFE plate material having a predetermined thickness, and has a substantially cylindrical void 4a to serve as the heat exchange chamber 4 in the vertical direction.
Are provided so as to penetrate in the vertical direction. The upper and lower surfaces of the side wall body 5 that surrounds the void become contact portions 5b with which the opposing surfaces of the heat transfer substrate abut via the chemical resistant coating layer. The contact portion 5b that surrounds the void 4a has a cross section. A seal groove 10 having a substantially rectangular shape is engraved so as to surround the void 4a in a loop shape.
By the way, the space 4a to be the heat exchange chamber 4 is partitioned by the partition plates 7a and 7b in the form of a battledore so as to form a meandering flow path, and the chemical solution inlet 6a is provided at one end of the meandering flow path and the other end is provided at the other end. The outlet 6b is open.

A ring-shaped jacket type gasket 20 is housed in the seal groove 10. The gasket 20 is composed of a loop-shaped core member 21 made of a fluororubber ring having a substantially rectangular cross section, and a ring-shaped jacket 22 surrounding the core member 21 from three sides. To be precise, the cross-sectional shape of the core member 21 is an isosceles trapezoid, and the outer peripheral surface 21a corresponding to the bottom of the trapezoid has a heat exchange among the peripheral wall surfaces 11 and 12 of the seal groove 10 facing each other. The heat exchange substrate 2 and the side wall body 5 are in contact with the outer peripheral wall surface 12 remote from the chamber 4 before the heat exchange substrate 2 and the side wall body 5 are clamped and fixed. Therefore, the inner peripheral surface 21b corresponding to the upper base of the isosceles trapezoid faces the inner peripheral wall surface 11 of the seal groove. The angle formed by the leg sides of the trapezoid and the lower base is extremely close to a right angle, for example, 85 to
It is appropriately selected within the range of 89 degrees.

A loop-shaped core material 21 having such a shape
The gasket 20 is formed by closely contacting the jacket 22 covering three sides of the core material 21 except for the contact peripheral surface (the lower base of the isosceles trapezoid) with the outer peripheral wall surface 12. The jacket 22 is made of a material having high chemical resistance such as PTFE or ETFE,
A pair of ridges 15, 15, 16, 16 is integrally formed on each of the peripheral surfaces of the seal groove 10 that face the bottom surface 14 and the opening surface 13. The ridges 15 and 16 have an isosceles trapezoidal shape (or a mountain shape) in cross section, and the heat transfer boards 2 and 2 are brought into contact with the side wall body 5 by the tightening bolts 9 that are inserted through the bolt holes 9a. By press-contacting the portion 5b, the projecting end of the projecting strip strongly presses the bottom surface 14 of the seal groove 10 and the chemical resistant sheet 3 to seal the heat exchange chamber 4.

Inner peripheral surface 2 of the core material 21 of the jacket 22
There is a very small gap between the peripheral surface of the jacket covering 1b and the inner peripheral wall surface 11 of the seal groove. The jacket 22 may be configured to completely cover the core material except for the outer peripheral surface 21a of the core material, or as shown in FIG. May be exposed.

[0026]

In the chemical-resistant heat exchanger of the present invention having such a structure, when the temperature rises, the loop-shaped core material 21 increases elasticity and expands in volume. Since the outer peripheral surface 21a of the core material is pressed and fixed by the outer peripheral wall surface 21a of the seal groove 10, the deformation of the core material due to the elasticity and expansion is exclusively
It is exerted on the jacket 22 that surrounds the core material from the other three sides and acts as a strong pressure on the upper and lower surfaces of the jacket in FIG. 3, which concentrates on the ridges, resulting in a strong sealing force. . At this time, the gap between the gasket 20 and the inner peripheral wall surface 11 of the seal groove acts as an escape space that allows a uniform expansion of the core material, and the core material is deformed due to excessive high pressure or partial bias pressure. Prevents loss of elasticity. The pair of ridges have a function of leveling the sealing force, and at the same time, even if a leak occurs in the inner ridge 15, the pressure applied to the seal portion of the outer ridge 16 is significantly reduced. The safety is extremely high because it has fallen to.

Further, when the temperature decreases, the elasticity of the core material decreases, the core material becomes stiff, and the compressive deformation also decreases. Furthermore, the low-temperature contraction of the core material progresses, and the loop-shaped core material 21 deforms so as to reduce the diameter. At this time, the jacket 22 and the core material 21
Since the core material 21 is made of different materials, the core material 21 is reduced in diameter in a state where a wedge is driven into the jacket 22 due to a difference in expansion, and the core material 21 having an isosceles trapezoidal cross section,
The sloped surface facing the ridges 15 and 16 strongly presses the ridge against the surface to be sealed, and compensates for the reduction in the sealing performance of the ridge due to the temperature decrease. The gasket 20 and the inner peripheral wall surface 2
Similarly, the gap with 1b serves as an escape space that does not hinder the diameter reduction of this gasket.

[0028]

[Effect] If the chemical resistance heat exchanger of the present invention is used as a chemical temperature controller, conventionally two identical chemical temperature controllers having the specifications shown in FIG. 4 are prepared, and a high temperature chemical temperature controller and a low temperature controller are used. As a temperature controller for chemical liquids, each of them was equipped with a circulation pump, a filter, a chemical liquid tank, a controller, etc., and was used as a dedicated device, and it was used properly according to the operating temperature. Space and management costs can be greatly improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a liquid temperature controller incorporating a heat exchanger according to the present invention.

FIG. 2 is a perspective view showing a structure of a side wall body of FIG.

3 is an explanatory view showing a part of the heat exchanger of FIG. 1 in an enlarged manner. FIG.

FIG. 4 is an explanatory diagram showing an example of a temperature control device for a corrosive chemical liquid.

FIG. 5 is an explanatory diagram showing an example of a conventional technique.

FIG. 6 is an explanatory diagram showing a part of FIG. 6 in an enlarged manner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chemical resistance heat exchanger 2 Heat transfer board 2a Opposed surface 3 Chemical resistance sheet 4 Heat exchange chamber 5 Side wall body 10 Seal groove 11 Inner peripheral wall surface 12 Outer peripheral wall surface 13 Opening surface 14 Bottom surface 15 and 16 Ridge 20 Gasket 21 Loop-shaped core material 21a Outer peripheral surface 21b Inner peripheral surface 22 Jacket

Claims (3)

[Claims] 1. A pair of heat transfer substrates, which are made of a material having good thermal conductivity and are arranged to face each other at a predetermined interval, and a chemical resistant coating layer which covers the facing surfaces of the pair of heat transfer substrates. A side wall body which is made of a chemical resistant material, is interposed between the pair of heat transfer boards, is in pressure contact with the heat transfer board through the chemical resistant coating layer, and surrounds a heat exchange chamber together with the heat transfer board, and the heat exchange. A fluid inlet / outlet for opening the chamber to the outside is provided, and a series of seal grooves surrounding the heat exchange chamber in a loop shape is provided at a pressure contact portion of the side wall body with the chemical resistant coating layer, and a gasket is provided in the seal groove. In a chemical-resistant heat exchanger that houses and seals a heat exchange chamber, the gasket has a loop-shaped core member made of a rubber elastic material, and a chemical resistance that covers the core member except at least the outer peripheral surface of the core member. And a jacket made of material. The outer peripheral surface of the core member is in contact with the peripheral wall surface of the seal groove on the side remote from the heat exchange chamber. A chemical resistant heat exchanger characterized by 2. A pair of heat transfer substrates which are made of a material having good heat conductivity and which are arranged to face each other at a predetermined interval, and a chemical resistant coating layer which covers the facing surfaces of the pair of heat transfer substrates. A side wall body which is made of a chemical resistant material, is interposed between the pair of heat transfer boards, is in pressure contact with the heat transfer board through the chemical resistant coating layer, and surrounds a heat exchange chamber together with the heat transfer board, and the heat exchange. A fluid inlet / outlet for opening the chamber to the outside is provided, and a series of seal grooves surrounding the heat exchange chamber in a loop shape is provided at a pressure contact portion of the side wall body with the chemical resistant coating layer, and a gasket is provided in the seal groove. In a chemical resistant heat exchanger that houses and seals a heat exchange chamber, the gasket is made of a rubber elastic material, and the cross-sectional shape is a loop-shaped core material whose thickness gradually decreases from a large diameter portion to a small diameter portion. , A jar made of a chemical-resistant material covering at least the outer peripheral surface of the core material And a pair of peripheral wall surfaces facing each other of the seal groove, each of which is provided with a protrusion on the peripheral surface of the jacket that faces the bottom surface of the seal groove and the opening surface of the seal groove. A gap is provided between the gasket and the inner peripheral wall surface on the side closer to the heat exchange chamber while the outer peripheral surface on the side far from the heat exchange chamber abuts the outer peripheral surface of the core material. A chemical resistant heat exchanger characterized by the following. 3. The seal groove is substantially U-shaped, and a plurality of trapezoidal or chevron-shaped protrusions are formed on each of the opposing peripheral surfaces of the jacket, and the cross-sectional shape of the loop-shaped core member is the outside of the seal groove. The chemical-resistant heat exchanger according to claim 2, wherein the chemical-resistant heat exchanger has an isosceles trapezoid having an outer peripheral surface abutting on the peripheral wall surface as a lower bottom.