JPH02102661A - Heat exchanger for medical treatment - Google Patents

Abstract

PURPOSE:To improve heat exchange capacity with a heat medium which flows from the upper part toward the lower part of heat transfer tubes by housing the many heat transfer tubes into a heat exchange chamber formed of a hollow core pipe and a housing and passing blood from an aperture bored in the lower part of the hollow core pipe toward the upper part. CONSTITUTION:The heat exchange chamber is formed between the cylindrical housing 1 and the hollow core pipe 2 erected to the center of the housing and the many heat transfer tubes 3 consisting of stainless pipes, etc., are housed in parallel with the hollow core pipe in the heat exchange chamber. The heat transfer tubes 3 are supported by partition walls 6, 6' of a high-polymer potting agent closing both ends of the housing in such a manner that both ends open. The top end of the housing 1 is covered by an upper head cover 7 having a heat medium inlet 10 communicating with the inner space of the heat transmission tubes 3 and a blood inlet 11 communicating with the inside of the hollow core pipe 2. The bottom end of the housing is covered by a lower head cover 8 having a heat medium outlet 13 communicating with the inside space of the heat transfer tubes 3. The aperture 9 communicating the inside of the hollow core pipe 2 and the heat exchange chamber is bored to the lower part of the hollow core pipe 2 and a blood outlet 19 communicating with the heat exchange chamber is provided to the upper side wall of the housing 1.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a heat exchanger used for heat exchange of blood in artificial lungs, whole body thermotherapy, etc., particularly an external perfusion type in which blood flows outside a heat transfer tube. The present invention relates to a heat exchanger.

(Prior art) Various types of heat exchangers have been widely used for heating and cooling blood in extracorporeal circulation blood circuits in conventional lung oxygenation, whole-body hyperthermia, etc.For example, heat exchangers made of stainless steel pipes A large number of heat exchanger tubes are accommodated in a cylindrical housing, supported by plastic partition walls that close both ends of the housing so that both ends thereof are open, and blood is allowed to flow inside the heat exchanger tubes.
Internal perfusion type multi-tube heat exchangers that flow a heat transfer medium outside the heat transfer tubes are widely used clinically.

(Problems to be Solved by the Invention) In such an internal perfusion type heat exchanger, if blood is evenly distributed and supplied to a large number of heat transfer tubes, there will be no blood channeling (unbalanced flow); Since the flow is completely laminar υ, it is necessary to reduce the inner diameter of the heat transfer tube in order to increase the heat exchange capacity (heat transfer rate per unit heat transfer area). However, even if the inner diameter of the stainless steel tube is reduced, the heat exchange performance will not be dramatically improved as long as blood flows in a laminar flow state. Furthermore, in this type of heat exchanger, it is difficult to cut the stainless steel tube to a predetermined length with high precision, and the cutting surface is roughened, resulting in blood damage.

On the other hand, the external perfusion method, in which blood flows outside the heat transfer tube, has very little risk of damaging the blood, and the distribution of the heat medium is good, but it is expected that turbulence will occur in the blood flow. However, there are problems such as a decrease in heat exchange performance due to blood channeling or a tendency for coagulation to occur in the blood retention area. Therefore, an object of the present invention is to provide a compact heat converter that has excellent heat exchange ability, has no blood stagnation or channeling, has low pressure loss, and has a small blood filling volume. Means for Solving the Problems) In order to achieve the above object, the present inventors have developed an external device that does not cause blood damage, has low pressure loss, and is expected to improve the gas exchange capacity per unit area. The present invention was achieved by focusing on perfusion type heat exchangers and conducting intensive studies to prevent blood channeling and blood stagnation, which are disadvantages of external perfusion type heat exchangers. That is, in the present invention, a hollow core tube is installed upright in the center of a cylindrical housing having a blood outlet on the upper side wall, and a large number of heat transfer tubes are housed in a heat exchange chamber formed by the housing and the hollow core tube. At the same time, the H-zinc is supported by a partition wall that closes both ends so that both ends are open, and an opening communicating with the heat exchange chamber is bored in the lower part of the hollow core tube, and an opening communicating with the heat exchange chamber is formed in the lower part of the hollow core tube. A rad cover is provided at an upper portion having a heat medium inlet communicating with the internal space of the heat transfer tube and a blood inlet communicating with the inside of the hollow core tube, and a lower portion having a heat medium outlet communicating with the internal space of the heat transfer tube at the lower end of the housing. This is a medical heat exchanger characterized by being equipped with a heat exchanger.

(Function) The heat exchanger of the present invention accommodates a large number of heat transfer tubes in a heat exchange chamber formed by a hollow core tube and a housing, and directs blood from an opening bored at the bottom of the hollow core tube toward the top. I try to let it flow. Therefore, it comes into contact with the heat medium flowing from the top to the bottom of the heat transfer tube in a nearly countercurrent state, improving heat conversion performance.

(Example) Next, an embodiment of the heat exchanger of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a heat exchanger, in which a heat exchange chamber is formed between a cylindrical housing 1 and a hollow core tube 2 erected at the center of the housing. A large number of heat transfer tubes 3 made of stainless steel pipes or the like are housed in the heat exchange chamber in parallel with the hollow core tube. The heat exchanger tube 3 is made of polyurethane with both ends of the housing closed so that both ends are open.

It is supported by partition walls 6 and 6' made of a polymeric botting agent such as silicone or epoxy resin. The upper end of the housing is covered with an upper rad cover 7 having a heat medium inlet lO communicating with the interior space of the heat transfer tube 3 and a blood port 11 communicating with the interior of the hollow core tube 2.

Further, the lower end of the housing 1 is covered with a lower head cover 8 having a heat medium outlet 13 communicating with the internal space of the heat transfer tube 3.

An opening 9 is bored in the lower part of the hollow core tube 2 to communicate with the inside of the hollow core tube 2 and the heat exchange chamber. In addition, the upper side wall of the cylindrical housing 1 has a blood outlet 19 that communicates with the heat exchange chamber.
is provided. A partition wall 1 is provided at the blood outlet portion of the housing 1.
4 may be provided, and an opening may be provided in the upper part of the partition wall 14 to communicate the blood outlet section and the heat exchange chamber.

The blood population 11 is as shown in FIG.
Moreover, an opening 15 in the partition wall 6 that closes the upper part of the hollow core tube 2 communicates the inner space of the head cover with the inside of the hollow core tube 2.
may be provided. Furthermore, as shown in Fig. 3, the hollow core tube 2
The blood guide device 16 may be inserted and fixed in a liquid-tight manner into the hollow core tube through the partition wall 6' that closes the lower end of the tube. It is preferable that the surfaces of the inner wall of the cylindrical housing 1, the inner and outer walls of the hollow core tube 2, and the outer wall of the heat exchanger tube 3, which come into contact with the blood, are finished as smooth as possible. Metal surfaces can be finished smooth by mechanical surface treatments such as puff finishing. Alternatively, instead of mechanical surface finishing, a polymer coating such as silicone may be formed on the surface after surface finishing. In this case, the coating must not have its components eluted into blood or peel off, and must be durable.

Next, the present inventors conducted the following experiment in order to confirm the effects of the heat exchanger of the present invention.

Experimental exception diameter 93. Made of polypropylene with a thickness of 2.511 m
A hollow core tube made of polypropylene with an outer diameter of 13 mm and a thickness of 2.5 mm is erected inside the housing, and a heat exchanger formed by the housing and the hollow core tube has an inner diameter of 4.01 mm. 160 stainless steel tubes with a thickness of 0.25 mm and an effective length of 7 Wm are accommodated, supported by a recessed wall made of polyurethane resin that closes both ends of the housing, and the heat transfer structure is as shown in Figure 1. Area 0.
A 14m" heat exchanger was manufactured.

On the other hand, we separately manufactured a heat exchanger without a hollow core tube.

The above two types of heat exchangers were tested using bovine blood heated to 37°C to evaluate heat exchanger performance (oxygenator performance). supplied.

(Effects of the Invention) As described above, the heat exchanger of the present invention allows blood to flow outside the heat exchanger tube, and moreover, allows the blood to flow upward from the outside of the heat exchanger tube through the opening bored at the bottom of the hollow core tube. Because of this, the inside of the heat transfer tube can be brought into contact with the heat medium flowing downward in a nearly countercurrent state, and a high heat exchange performance as shown in the experimental example can be obtained. In addition, the heat exchanger of the present invention is an extremely safe heat exchanger that does not cause blood damage because all contact surfaces with blood can be made smooth6.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views of the medical heat exchanger of the present invention. 1...Housing 2...Hollow core tube 3...Heat transfer tube 6.6'°°°°゛°Partition wall 7. ...... Engraving of Rad cover drawing to the top (Contents (=no changes) 1st Figure 10...Heat medium inlet 11...Blood inlet 13 ...Heat medium outlet 19 Kinzume O Patent applicant Rira Shi Co., Ltd.

Claims (1)

[Claims] A hollow core tube is placed upright in the center of a cylindrical housing having a blood outlet on the upper side wall, and a large number of heat transfer tubes are housed in a heat exchange chamber formed by the housing and the hollow core tube. The housing is supported by partition walls that close both ends of the housing so as to be open, and an opening communicating with the heat exchange chamber is provided at the lower part of the hollow core tube, and an opening communicating with the internal space of the heat exchanger tube is formed at the upper end of the housing. An upper head cover having a heat medium inlet and a blood inlet communicating with the inside of the hollow core tube is provided, and a lower head cover having a heat medium outlet communicating with the internal space of the heat transfer tube is provided at the lower end of the housing. medical heat exchanger.