JPH0975451A - Heat exchanger with high bubble removing function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep the uniform flow distribution of a heat exchange fluid and improve a bubble removing function by forming a heat fluid inlet at the lower end of a heat exchange fluid chamber and a heat exchange fluid outlet at the upper end of the chamber, and inclining the heat exchange fluid contact surface of at least the upper end seal material of seal materials at both ends, relative to horizontal surface. SOLUTION: A heat exchange fluid introduced via a heat exchange fluid inlet 5 flows vertically upward in a housing to perform a heat exchange process, and flows out from a heat exchange fluid outlet 2. In this case, the wetted surfaces 6 and 7 of seal materials at both ends of a heat exchanger are formed in such a state as inclined for a horizontal surface. In other words, the surfaces 6 and 7 are respectively inclined so as to rise in a direction for parting from the heat exchange fluid inlet and outlet 5 and 2. According to this construction, bubbles entering a heat exchange fluid chamber 8 move upward along a slope and do not stagnate at such a position as the connection of the seal materials and straight tubes. Also, the bubbles are removed from the heat exchange fluid outlet 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger installed in an extracorporeal blood circulation circuit for heating or cooling a heat exchange fluid containing blood, myocardial protection liquid and the like.

[0002]

2. Description of the Related Art During cardiac surgery, it is necessary to perform extracorporeal circulation using a blood circuit as an alternative means for the functions of the heart and lungs. In this blood circuit, an artificial lung for enriching (adding) oxygen to blood, a blood pump for sending blood, a blood reservoir for adjusting the blood volume in the circuit (securing a certain blood volume), A blood filter for removing air bubbles mixed in the circuit, a heat exchanger for cooling and heating the temperature of blood or myocardial protection liquid, and the like are incorporated. In heart surgery, a heat exchanger cools blood or cardioplegic solution such as crystalloid that flows in the blood circuit (for example, about 10 to 15).
C.) and then suppress the metabolic function of the heart by cooling the patient's heart tissue. Further, after the operation is completed, the metabolic function of the heart can be returned to the original state by circulating the cardioplegia solution that has been reheated to the living body temperature. Various shapes of the heat exchanger have been devised. For example, there is a heat exchanger in which a straight metal tube whose both ends are fixed by sealing materials is arranged in a cylindrical housing. . This heat exchanger circulates a myocardial protection liquid in the housing (outside the straight pipe) and a medium for heat exchange in the straight pipe so that the heat medium and the myocardial protection liquid exchange heat through the straight pipe. I do. In addition to the cardiac surgery, it may be necessary to locally lower or raise the body temperature as described above. (For example, in brain surgery or organ surgery other than heart) In such a case, a heat exchanger similar to the above is required,
It was not rare that it was actually used.

[0003]

However, the conventional heat exchanger has the following two contradictory problems. One is a decrease in heat exchange efficiency due to channeling (deflection flow; non-uniform flow state depending on regions), and the other is difficulty in bubble removal and increase in pressure loss. That is, in order to prevent the heat exchange fluid from flowing only to the region where the heat exchange fluid easily flows (particularly, the space region between the inner wall of the housing and the straight pipe adjacent thereto) by the channeling, only the region where the heat exchange fluid easily flows directly. A heat exchanger in which the arrangement density of the tubes is high and the arrangement density of the straight tubes is the same as that of the other regions is desirable. Further, from the viewpoint of increasing the heat exchange rate, a material for increasing the arrangement density of the straight pipes is preferable. Such a heat exchanger has little channeling, flows relatively uniformly in every region, and has a high straight tube arrangement density, so that the heat exchange rate increases. However, the above structure makes it difficult for the mixed bubbles to flow out. Especially, it is difficult to remove bubbles accumulated between the straight pipe and the straight pipe or between the straight pipe and the inner wall. If the air bubbles remain in the blood circuit in this way, the air bubbles may be mixed into the blood during extracorporeal blood circulation, which may cause a risk of life. If the density of straight pipes is increased to improve the channeling and heat exchange efficiency, or if the heat exchanger is designed to reduce the gap, the flow resistance of the heat exchange fluid in the heat exchanger increases. As a result, the pressure loss between the heat exchange fluid inlet and its outlet becomes large. However, in order to improve bubble removal and reduce pressure loss, the distribution density of straight pipes and the straight pipes close to the inner wall should be reduced so that the flow resistance of the blood, which is the flow medium of the bubbles, in the heat exchanger becomes small. Even if only the space region of and is changed, channeling occurs as in the original case, and the heat exchange rate decreases. As mentioned above, if the disposition density of straight pipes is increased to improve the channeling or heat exchange rate, or if the space of the straight pipes close to the inner wall of the housing is narrowed, the ability to remove bubbles becomes poor and the pressure loss is reduced. Will increase. On the contrary, when trying to improve the air bubble removal property and the pressure loss, there is a dilemma that channeling easily occurs and the heat exchange rate decreases. Therefore, an object of the present invention is to provide a heat exchanger in which the distribution state (representing the flow state) of a heat exchange fluid containing blood, cardioplegic solution, etc. is more uniform and good, and the bubble removal performance is improved. It is to be.

[0004]

A first aspect of the present invention is to provide a heat exchange medium outlet provided on one end side of the upper end side and the lower end side and another heat exchange medium outlet side. A heat exchange medium inlet, a tubular housing (A) having a heat exchange fluid inlet and a heat exchange fluid outlet provided between the medium inlet and the medium outlet, A large number of heat exchange straight pipes (B) arranged in the cylindrical housing (A), and both ends of the straight pipe are fixed to both ends, and the heat exchange fluid inlet and the heat exchange fluid are used. Heat exchange fluid chamber (C) communicating with the outlet
A heat exchange medium chamber (D) communicating with the heat exchange medium inlet and the heat exchange medium outlet, and both ends of the plurality of heat exchange straight pipes (B) are fixed, and the heat exchange medium chamber (D)
A heat exchanger having a sealing material (E) at both ends for liquid-tightly separating the heat exchange fluid chamber (C), and a heat exchange fluid flow at the lower end side of the heat exchange fluid chamber (C). A heat exchange fluid outlet is provided at the inlet and the upper end, and a contact surface (liquid contact surface) of the seal material (E) on both end sides with the heat exchange fluid (hereinafter, also referred to as a liquid contact surface). By using at least one of those inclined to the horizontal plane,
The above technical problems have been solved. That is, as described above,
Since the liquid contact surface of the seal material (E) is inclined, the bubbles mixed in the heat exchange fluid chamber (C) do not stagnate at the joint between the seal material (E) and the straight pipe (B). Thus, it becomes easy to move diagonally upward along the inclination. The second aspect of the present invention is to provide a heat exchange medium outlet provided on the lower end side, a heat exchange medium inlet provided on the upper end side, and a position between the medium inlet and the medium outlet. A cylindrical housing (A) having a heat exchange fluid inlet and a heat exchange fluid outlet provided,
A large number of heat exchange straight pipes (B) arranged in the cylindrical housing (A), and both ends of the straight pipe are fixed to both ends, and the heat exchange fluid inlet and the heat exchange fluid are used. A heat exchange fluid chamber (C) communicating with the outlet, a heat exchange medium chamber (D) formed in the straight pipe communicating with the heat exchange medium inlet and the heat exchange medium outlet, and the plurality of heat exchanges Heat exchange having both ends of the straight pipe (B) fixed, and sealing materials (E) at both ends for liquid-tightly separating the heat exchange medium chamber (D) and the heat exchange fluid chamber (C) In the container, a heat exchange fluid inlet is provided on the lower end side of the heat exchange fluid chamber (C), and a heat exchange fluid outlet is provided on the upper end, and at least the inner wall of the heat exchange fluid chamber (C) is provided. The above technical problem has been solved by providing a part of a vertically long rib along the liquid flow direction. That is, a vertically long rib (F) is formed on the inner wall of the heat exchange fluid chamber (C) of the heat exchanger.
Is provided in the vertical direction, the heat exchange fluid can be evenly distributed in the housing without causing channeling in which the heat exchange fluid is unevenly flowed only to the inner wall surface side of the housing (A). As the heat exchanger of the present invention, it is preferable to combine the second technical solution with the first technical solution because the effects based on the respective means can be exhibited. Further, the heat exchange medium inlet of the present invention is provided on the upper end side of the cylindrical housing, and the heat exchange medium outlet is provided on the lower end side of the cylindrical housing, so that the heat exchange medium flows in the direction opposite to the heat exchange fluid. This is preferable from the viewpoint of heat exchange efficiency. Further, as the heat exchanger of the present invention, the groove (G) is provided along the inner peripheral wall of the lower portion and / or the upper portion of the heat exchange fluid chamber (C), preferably along the inner peripheral wall of both the lower portion and the upper portion. It is preferable to provide a groove (G) having an inclination angle similar to that of the seal material. The groove (G) can be formed, for example, on the inner peripheral wall between the liquid contact surface of the sealing material (E) and the end of the rib (F) arranged on the inner peripheral wall. At least a part of the opening of the groove (G) is preferably installed so as to open to the heat exchange fluid inlet and the heat exchange fluid outlet. By providing the groove (G), the heat exchange fluid introduced from the heat exchange fluid inlet on the lower end side of the heat exchanger uniformly flows into the groove (G), so that the heat exchange fluid chamber ( C) There is an effect of flowing vertically in the inside. Similarly, by providing a similar groove (G) in the upper part of the heat exchange fluid chamber (C), the heat exchange fluid flows into this groove and bubbles are generated in the joint portion between the rib and the seal material (E). It is removed without stagnation (it is easy to discharge even if air bubbles exist). Except for each of the features of the present invention described above, the heat exchanger of the present invention is installed in an extracorporeal blood circulation circuit and conventionally used to heat or cool a heat exchange fluid containing blood, myocardial protection liquid, or the like. The heat exchanger may have a structure similar to that of the conventional heat exchanger. Examples of the heat exchanger of the present invention include P.I. F. (Heat exchange efficiency coefficient) = 0.96 or more is preferable.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. In the heat exchanger shown in FIGS. 1 and 2, the heat exchange fluid inlet 5 and the heat exchange fluid outlet 2 are symmetric with respect to the liquid flow direction axis of the housing, that is, opposite to each other in the cylindrical housing. It is provided on the side. Moreover, the heat exchange fluid inlet 5 is provided on the lower end side of the heat exchange fluid chamber, and the heat exchange fluid outlet 2 is provided on the upper end side of the heat exchange fluid chamber. The heat exchange fluid outlet port 2 is a multi-branch pipe as shown in FIG. 2, the branch pipe 2'is a pressure monitor line connection port, and 2 "is a temperature sensor insertion port. The heat exchange fluid introduced from the inlet 5 then flows vertically upward inside the housing, at which time the liquid contact surfaces 6 and 7 of the seal material on both ends of the heat exchanger are inclined with respect to the horizontal plane. That is, the seal on the lower end side is
The liquid contact surface 7 of the seal material rises as the distance from the heat exchange fluid inlet 5 increases, and the liquid contact surface 6 of the seal material on the upper end side decreases as the distance from the heat exchange fluid outlet 2 increases. ing. Since the liquid contact surface 7 of the seal material is inclined in this way, the bubbles mixed in the heat exchange fluid chamber 8 do not stay in the joint between the seal material and the straight pipe 3 and the like. It becomes easy to move diagonally upward along the. Finally, the bubbles that have moved to the uppermost part of the heat exchange fluid chamber 8 in the housing are removed from the heat exchange fluid outlet 2 that is provided near the uppermost part of the heat exchange fluid chamber 8. It The angles of inclination of the seal materials on the lower end side and the upper end side may be the same or different. When the inclination angle of the seal material on the lower end side differs from that of the seal material on the upper end side, if the difference in inclination angle is too large, the heat exchange area decreases, so the difference in inclination angle is preferably within 25 °. , For example, when they are substantially the same. Further, when the inclined portion is provided on either the lower end side or the upper end side, since the bubble removal performance is particularly affected by the inclination of the upper end side seal material, the inclined portion is provided on the upper end side. However, it is preferable that the sealing material on the lower end side is also inclined, because bubbles are more likely to escape from the sealing material on the lower end side.
The inclination angle of the lower end side and / or the upper end side is preferably 5 ° to 40 °, more preferably 10 °.
~ 35 °. This is because if the inclination angle is less than 5 °, the bubble removing effect is small, and if it exceeds 40 °, the heat exchange area is reduced and the heat exchange rate is reduced. In particular, as shown in FIG. 2, the housing is a rectangular parallelepiped, and four tangent lines L, M, N, and O obtained by contacting the seal material, for example, the seal material on the lower end side and the inner wall surface of the housing. However, that any two adjacent tangent lines are inclined to the horizontal plane, that is, the seal material is installed so that the inclination of the surface formed by the four tangent lines becomes three-dimensional. However, it is preferable for the reason of improving the bubble removing performance. As shown in FIG. 3, ribs 10 are provided on the inner wall surface of the housing wall 9 of the heat exchange chamber so as to be arranged between the housing wall 9 and the straight pipe 11 adjacent thereto.
Was provided. It is preferable that the rib 10 has an R portion so that liquid or air bubbles do not stay therein, and that the R portion has a diameter particularly similar to the diameter of a straight pipe in order to obtain uniform dispersibility. The ribs 10 can be evenly distributed in the housing without the occurrence of channeling that is unevenly distributed only on the inner wall surface side of the housing 9 when the ribs are not provided. When the tubular housing has a rectangular parallelepiped shape as shown in FIG. 2, the ribs 10 may be provided on all side surfaces of the tubular housing, but normally, the heat exchange fluid inlet 5 and the heat exchange fluid outlet 2 are provided. Channeling can be substantially prevented if it is provided on the inner wall surface of the side surface other than the opposite side surface provided with. In addition, the one with the R part at the corner of the cylindrical housing is
It is effective in terms of bubble removal performance and fluid retention (which results in improved heat exchange efficiency). Further, the needle tube 1 corresponding to the R portion of the corner of the housing
It is preferable that the four corners of the needle array plate for fixing both ends of 1 are chamfered and have R portions. Hereinafter, the heat exchanger of the present invention will be described in detail based on Examples of the present invention.

[0006]

【Example】

Example 1 A heat exchanger having the structure shown in FIG. 1 and having the sealing material inclination angle, the number of needle tubes (pieces), the effective length (mm) and the heat exchange area (cm ² ) shown in Table 1 below. Is used as a heat exchange fluid, and tap water of 30 ± 1 ° C. is introduced from the heat exchange fluid inlet 5 at a flow rate of Q _B (heat exchange fluid flow rate) of 300 ml / min, and 40 ± 1 ° C. as a heat exchange medium. Tap water from the heat exchange medium inlet 1 to Q _W (heat exchange medium flow rate)
Blood was introduced at a flow rate of 5 L / min to exchange heat with blood.
The sample A corresponds to the embodiment corresponding to the comparative example of the present invention, and the sample C corresponds to the embodiment corresponding to the present invention. The sample A has a needle tube arrangement when the normal cylindrical housing shown in FIG. 4 is used, whereas the sample C has a cylindrical housing with R at each corner of the sample A and the needle tube shown in FIG. This is a case where needle tubes with two needle tubes at each corner of the array are arranged so as to correspond to the R portion of the cylindrical housing. The P. cerevisiae achieved by the embodiment carried out on the basis of samples A and C above. F. The (heat exchange efficiency coefficient) values are shown in Table 1. From the results of this implementation, the effective length of the needle tube of sample C (m
m) and heat exchange area (cm ² ) are reduced compared to those of sample A, although the P.I. F. If the value is the P. It is surprising that it does not change compared to the F value, and adding R to each corner (4 corners) of the housing is the same as P.F. F. It shows that it is effective in improving the value. In addition, the sample C has the same P.O. F. Although the value is achieved, it is presumed that the retention of the heat exchange fluid was reduced by adding R to the four corners of the housing.

[0007]

[Table 1] The R. F. Value is Q _B (heat exchange fluid flow rate) = 300 m
1 / min Q _W (heat exchange medium flow rate) = 5 L / min.

Example 2 Using the heat exchanger shown in FIG. 1, differences in bubble removability when the inclination angle of the liquid contact surface of the sealing material was changed were examined. The heat exchanger shown in FIG. 1 was arranged in the blood circuit, and tap water at room temperature was perfused as a heat exchange fluid. The difficulty of removing bubbles from the heat exchange medium chamber when bubbles were mixed from the upstream side of the heat exchanger during tap water perfusion was evaluated. The heat exchange fluid flow rate was 300 ml / min. The results are shown in Table 2 below.
Shown in

[0009]

[Table 2] × ・ ・ ・ ・ Difficult to remove air bubbles even by tapping operation △ ・ ・ ・ ・ Need tapping operation to remove air bubbles ○ ・ ・ ・ ・ Can remove air bubbles by tilting the heat exchanger (no tapping operation required) ◎ ・ ・ ・ ・Allowing spontaneous discharge of bubbles From the results shown in Table 2 above, it is understood that angling the liquid contact surface of the sealing material is effective for removing bubbles. Further, it has been found that the angle needs to be 5 ° or more for large bubbles and 15 ° or more for small bubbles.

Example 3 The same procedure as in Example 1 was carried out using a heat exchanger with and without ribs, and the presence or absence of ribs in the heat exchanger was determined as follows. F. The effect on value was tested. Tap water of 30 ± 1 ° C. was introduced as a heat exchange fluid. Flow rate is 180, 24
It was set to 0, 300 ml / min in three ways. As the heat exchange medium, tap water of 40 ± 1 ° C. was caused to flow at a flow rate of 5 L / min. The results are shown in Table 3 below.

[0011]

[Table 3]

[Equation 1] TBout: Temperature of heat exchange fluid on outlet side TBin: Temperature of heat exchange fluid on inlet side TWin: Temperature of heat exchange medium on inlet side The results of the above table show that the heat exchange efficiency can be improved by providing the ribs, that is, effectively. It shows that channeling can be prevented.

[0012]

Since the heat exchanger of the present invention is less likely to cause channeling, the heat exchange rate is improved. Further, it is excellent in the performance of removing bubbles mixed in the heat exchanger, and the risk of injecting bubbles into the living body is reduced.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a heat exchanger according to an example of the present invention. .

FIG. 2 is a perspective view of a heat exchanger of an example of the present invention.

FIG. 3 is a cross-sectional view of the heat exchanger of FIG. 2 as seen from the ← direction.

FIG. 4 is an example of a needle tube arrangement of a conventional heat exchanger.

FIG. 5 is a needle tube arrangement of the heat exchanger used in Example 1 in which R portions are provided at four corners.

[Explanation of symbols]

 1 Heat exchange medium inlet 2 Heat exchange fluid outlet 2'Pressure monitor line connection port 2 "Temperature sensor insertion port 3 Heat exchange straight pipe 4 Heat exchange medium outlet 5 Heat exchange fluid inlet 6 Upper end Seal material liquid contact surface 7 Lower end seal material liquid contact surface 8 Heat exchange fluid chamber 9 Housing wall 10 Rib 11 Needle tube 12 R part L Tail line between the seal material and housing inner wall surface M Seal material and Tangent line where the inner wall surface of the housing is in contact tangent line where the N seal material is in contact with the inner wall surface of the housing O Tangent line where the seal material is in contact with the inner wall surface of the housing

Claims (10)

[Claims] 1. A heat exchange medium outlet provided on one end side of the upper end side and the lower end side, a heat exchange medium inlet port provided on the other end side, and the medium. A tubular housing (A) having a heat exchange fluid inlet and a heat exchange fluid outlet provided between the inlet and the medium outlet, and disposed inside the tubular housing (A) A plurality of heat exchange straight pipes (B), a heat exchange fluid chamber (C) communicating with the heat exchange fluid inlet and the heat exchange fluid outlet, the heat exchange medium inlet and the heat exchange medium A heat exchange medium chamber (D) communicating with the outlet and both ends of the plurality of heat exchange straight pipes (B) are fixed, and the heat exchange medium chamber (D) and the heat exchange fluid chamber (C) are fixed. In a heat exchanger having sealing materials (E) at both ends for liquid-tightly separating the heat exchange fluid from the heat exchange fluid chamber (C), A body inlet, a heat exchange fluid outlet is provided at the upper end portion, and at least the seal material on the upper end portion side of the seal material on the both end side contact surfaces with the heat exchange fluid (hereinafter, (Also referred to as a liquid contact surface) is inclined with respect to a horizontal plane. 2. A heat exchange medium outlet provided on the lower end side, a heat exchange medium inlet provided on the upper end side, and a position provided between the medium inlet and the medium outlet. A tubular housing (A) having a heat exchange fluid inlet and a heat exchange fluid outlet, and a plurality of heat exchange straight pipes (B) arranged in the tubular housing (A), A heat exchange fluid chamber (C) communicating with the heat exchange fluid inlet and the heat exchange fluid outlet
A heat exchange medium chamber (D) communicating with the heat exchange medium inlet and the heat exchange medium outlet, and both ends of the plurality of heat exchange straight pipes (B) are fixed, and the heat exchange medium chamber (D)
In a heat exchanger having sealing members (E) at both ends for liquid-tightly separating the heat exchange fluid chamber (C), a heat exchange fluid inlet port is provided on a lower end side of the heat exchange fluid chamber (C). A heat exchange fluid outlet is provided at the upper end, and a longitudinally long rib (F) along the liquid flow direction is provided on at least a part of the inner wall of the heat exchange fluid chamber (C). A heat exchanger characterized by. 3. The heat exchange medium inlet is provided at the upper end side of the tubular housing, and the heat exchange medium outlet is provided at the lower end of the tubular housing. The heat exchanger according to 2. 4. The heat exchanger according to claim 2 or 3, wherein the liquid contact surface of at least the upper end side seal member of the seal members (E) on both end sides is inclined with respect to a horizontal plane. A heat exchanger characterized in that 5. The heat exchanger according to claim 1, 3 or 4, wherein the inclination of the lower end side seal material (E) increases as the distance from the heat exchange fluid inlet increases, and the upper end side seal is also increased. The heat exchanger characterized in that the inclination of the material (E) on the liquid contact surface side is lowered as the distance from the heat exchange fluid outlet is increased. 6. The heat exchanger according to claim 1, 3, 4 or 5, wherein the inclination angle of the liquid contact surface of the seal material (E) at the upper end portion and / or the lower end portion is 5 to 35 °. A heat exchanger characterized by. 7. The heat exchanger according to claim 1, 2, 3, 4, 5 or 6, wherein a groove (G) is provided along an inner peripheral wall of a lower portion and / or an upper portion of the heat exchange fluid chamber (C). A heat exchanger characterized by that. 8. The method of claim 1, 2, 3, 4, 5, 6, or 7.
The heat exchanger according to claim 1, wherein the cylindrical housing (A) has chamfered R portions at four corners, and the four corners of the needle tube array plate (H) for fixing both ends of the needle tube are the cylindrical shape. A heat exchanger characterized by being chamfered so as to correspond to the R part of the housing (A). 9. The method of claim 1, 2, 3, 4, 5, 6, or 7.
The heat exchanger according to claim 1, wherein a vertically long rib is provided between the inner wall of the cylindrical housing and a straight pipe adjacent thereto. 10. The heat exchanger according to claim 1, which is for installation in an extracorporeal blood circulation circuit.