JPS6064187A - Heat exchanger - Google Patents

Abstract

PURPOSE:To eliminate the possibility of breakage by a method wherein a ceramic pipe, communicating the supplying port of a fluid to be heated with the outflow port thereof, is suspended in parallel to the axial direction by a compression spring cooled by the fluid to be heated. CONSTITUTION:When high-temperature exhaust gas is flowed into the flow path of heat transfer fluid in a frame body 1 and the normal-temperature fluid to be heated is sent into a plurality of ceramic pipes 5, provided with supporting pipes 8, 9 communicated with the through holes 10, 10' of opposing wall surfaces 2, 2', from a supplying port 3, heat exchange is effected between the high-temperature exhaust gas and the fluid to be heated through the walls of the ceramic pipes. The ceramic pipes 5 can be slid slightly into the axial direction thereof by the compression springs 14 provided between the supporting pipe 8 of one side and the wall surface 2. According to this method, heat may be retrieved efficiently from the high-temperature exhaust gas or corrosive gas of 1,000 deg.C or more, further, ununiform thermal ecpansions or contractions, generated in respective ceramic pipes, may be absorbed and the breakage of the ceramic pipes may be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of industrial application) The present invention relates to a shell-and-tube heat exchanger for recovering waste heat discharged from various industrial furnaces.

(Prior art) Recovering waste heat from various industrial furnaces using a heat exchanger to preheat air for burning is widely used as the most effective energy-saving measure. A shell-and-tube heat exchanger has been put into practical use. However, in conventional heat exchangers of this type, stainless steel m-tubes are used as heat transfer tubes to bend the heated fluid, so the allowable heat resistance temperature is approximately 800°C, which takes into account internal cooling by air flow. Mo / OQ O” (
Stainless steel pipes cannot be used for heat exchange with exhaust gas at temperatures higher than S or higher, and stainless steel pipes are easily corroded by exhaust gas, so they have the disadvantage that their range of use is severely limited depending on the composition of the exhaust gas. Attempts have been made to use ceramic tubes, which have excellent heat resistance and corrosion resistance, as heat transfer tubes, but compared to ceramic 9F+ metal tubes, which cannot be welded to support walls like metal tubes. Due to large dimensional errors during manufacturing, it is difficult to hold the support wall closely, and
If the support wall is firmly attached by some means, it is more brittle than a metal tube and is more likely to be damaged by thermal stressC? i
There are many problems.

(Object of the Invention) The present invention solves these problems and can be used for exhaust gas with a high temperature of 1000°C or more or corrosive tJl gas, and also eliminates the risk of damage to the support wall. This was completed with the aim of creating a heat exchanger that allows heat exchanger tubes to be easily and accurately removed without being damaged.

(Structure of the Invention) The present invention provides a plurality of ceramic tubes, which are connected to a supply port and an outlet port for a fluid to be heated, between opposing walls of a frame whose interior is formed into a heat transfer fluid flow path. A compression spring cooled by a heated fluid is installed in parallel to absorb the expansion and contraction of the ceramic tube in the axial direction.

Next, the present invention will be explained in detail with reference to the illustrated embodiments.

In the first embodiment shown in FIGS. 1 and 2, (1) is a metal frame having openings on both upper and lower surfaces, and the inside thereof is formed as a flow path for heat transfer fluid such as high-temperature exhaust gas. a fluid inflow chamber (3) provided with an opposing wall surface (2) of the frame (1) and a supply port (3) for heated fluid on the outside of the wall surface (2);
A fluid outlet chamber (4) is provided with an outlet (4). (5) is formed with fins (6) for heat resistance and corrosion resistance such as silicon carbide, and these ceramic tubes (5)
) is sandwiched between the hexagonal columnar wall structure (7), <rfn+], and the outside of the wall structure (7), (7) is n
iJ wall and wall surface), (2) many through holes 01
, a metal support tube (8) and a support tube (
In this way, a large number of ceramic tubes (5) are installed in parallel between the wall surfaces T2) and (2). In addition, the wall structure (7)/ (7) is made of a ceramic material such as silicon carbide like the ceramic tube (5), and has a through hole 0υ equal to the inner diameter of the ceramic tube (5) in the center. 0υ is provided in the axial direction, and the joint surface μ4 between each wall structure (7), (7) and the ceramic tube (5), Ga and the wall surface (A), (7f) and the support tube ( The joint surfaces (1, 1, θ) with 8) and (9) are all formed into spherical surfaces, and the supply port (
A compression spring 04) is installed which is cooled by being exposed to the heated fluid supplied from 3). This support tube (
8) is shown in Fig. 2, and the through hole θ in the wall (2) is
It consists of a metal outer tube (, ra) welded around Q, and an inner tube (Jb) that can slide in the axial direction while keeping the inner circumferential direction of this outer tube (Ja) in close contact. Inside the outer tube (JR), the rear end is supported on the wall surface (2), and the front end is supported by the inner W.
The compression ring 0 is provided in contact with the inner pipe G! rb) It is pushed out by the compression spring 041 on the side of t and its convex spherical tip is
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No. 1 iiF 44' 6) fiha iMi 1 1
In addition, the outer support pipe (9) of the other wall structure (7) has a retaining flange (9) at its rear, and the wall structure The ceramic tube (5) supports the wall surface (2) immovably by the elastic force of the compression spring 041 while its both ends are held between the wall surface structures (7), (7). ), (
2) axial expansion, Il, elastically constructed between
V compression is absorbed by these 14 compression springs θ,
This ceramic tube (5) includes the wall structure (7), (
7) By communicating with the fluid inflow chamber (3) and fluid outflow chamber (4) through the support tubes (8), (9) and the through holes 01 and Q[J of the walls (2) and (2), Pipe (5
) forms a flow path for the heated fluid to flow through the inside of the tube.

In addition, when all the ceramic tubes (5) are installed between the wall surfaces (2), (2), the outer surfaces of the wall structures (7), (7) cover each other and form the frame (1). This system has airtight walls on both sides of the inside of the pipe, and the inside surrounded by these walls is used as a heat transfer fluid flow path through which high-temperature exhaust gas flows, thereby preventing exhaust gas leakage and compressed sedge links. Compression 119270 acting as a heat insulating wall of Q41
This prevents the elasticity of the straw from decreasing. Furthermore, as shown in the figure, a ceramic tube (5) and m-plane structures (7), (7j
A dividing fluid 0119 made by Nanau Mix with radial partition walls is fitted inside the ceramic tube (5), which finely divides the air flow flowing inside the ceramic tube (5) to increase the film heat transfer coefficient inside the ceramic tube. I'm letting you do it. In addition, in the above embodiment, support on the inflow side? ? (8) and wall rhj (2
), but a compression spring may also be provided between the support pipe (9) on the discharge side and the wall surface (2). Is tm outside? ! ′
. This is a gland packing provided on the joint surface between a) and the inner pipe σb). Furthermore, the wall structure (7) of this embodiment,
(7) When all the ceramic tubes (5) are arranged in parallel between the opposing walls (2), (2) of the frame (1), the outer surfaces of the wall structures (7), (7) Closely fit the frame 1]
By configuring an airtight wall surface inside the frame (1)
Although this is designed to prevent leakage of exhaust gas flowing inside the ceramic tube, it is also possible to omit this and directly support both ends of the ceramic tube (5) with the supports W (8) and (9). , Also, the support tube (8) and the compression spring θψ
Various liquid forms are also possible, for example @
As shown in Figure 3, the inner tube (Jc) is welded to the wall surface (2), and the outer tube σ presses the wall structure (7),
As shown in 1A7, the support tube (8) may be a single tube, the rear end of which is passed through the through hole 4 of the wall surface (2), and the compression spring Q41 may be attached to the outside thereof. In this case, the compressed nugling a plaster is installed between the flange (8) protruding from the n11 part of the support tube (8) and the pedestal Q camphor welded around the through hole in the wall surface (2), Press the wall structure (7) towards the ceramic tube (5) via the support tube (8).
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The compressed spring Q41 is cooled by the heated fluid that is separated from the supply port (3) through this narrow gap aυ with a width of approximately A wall surface facing the flow (2),
(Support pipe (3) connected to the 2f through hole □0%aL/,
If a fluid to be heated at room temperature is sent from the supply pipe 3) to a large number of ceramic tubes (5) equipped with (9) at both ends through the support tube (8), the tube walls of these ceramic tubes (5) The fact that heat exchange is performed between the heating fluid and the dvd tube is the same as in conventional heat exchangers of this type, but in the present invention, the heat exchanger tube has excellent heat resistance and corrosion resistance. Because the ceramic tube (5) is used, it is possible to exchange heat with the exhaust gas at a temperature of over 100°C, compared to the conventional method that could only be used for exhaust gas at a temperature of 100"C or less. In addition to providing much better thermal efficiency than heat exchangers, it also recovers heat from corrosive gases, which is not possible with heat exchangers using metal heat transfer tubes. Furthermore, when such high-temperature exhaust gas is introduced into the frame (1), each ceramic tube (5) undergoes significant thermal expansion, and furthermore, the expansion pattern ii. However, in the present invention, each ceramic tube (5) has at least one support tube (8).
The compression spring installed between the wall surface (2) and the wall surface (2) allows it to slide upward in the axial direction, so each ceramic!
The non-uniform thermal expansion of (5) is absorbed individually by each compressed slab ring U~, causing thermal stress in the ceramic tube (6).
damage can be prevented, and these compression springs have 0
The pressing force from the shovel is applied to the ceramic tube (5) and the wall structure (
7), (7) or between the wall structure (7), (7) and the support tubes (8), (9) to bring them into close contact with each other, so that the heated fluid flows outside. It can prevent leakage. Moreover, since the compression springs are constantly cooled by being exposed to the flow of the heated fluid supplied from the supply port (3), there is no elastic deterioration due to high temperature exhaust gas even after long-term use, and the wall surface Between (2) and (2), the ceramic tube (5) is properly and closely held, and efficient heat exchange can continue.

(Effects of the Invention) As is clear from the above description, the present invention is capable of recovering heat from the conventional shell-and-tube heat exchanger using heat transfer tubes made of #4 gold. I couldn't do it 1
It is possible to efficiently recover heat from exhaust gases and corrosive gases that are hotter than ooo''C, and in addition, by individually absorbing the uneven thermal expansion and contraction that occurs in each ceramic tube with a compression spring, It can prevent damage to pipes due to thermal stress and can also be compressed.

Both ends of the ceramic tube are held closely between the walls using the pressing force of the ring t, and this compression spring continues to cool while heat exchange is performed by the heated fluid supplied from the supply port. This has various advantages such as the compression spring can be used for a long period of time and there is no need to install any special cooling mechanism, which reduces the cost. It is extremely useful in contributing to the development of the industry as a product that has solved the problem of melting point.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing an embodiment of the present invention, Fig. 2 is a partially cutaway front view of the main part, and Figs. 3 and 7 are main parts showing other embodiments of the invention. Partial cutout 11: This is a side view. (02 frame body, (2), (2): wall surface, (3): supply port,
(4): Outlet, (5): Ceramic tube, (8): Support tube, 0 slope: Compression spring, α7): Slit.

Claims (1)

[Scope of Claims] /, The interior is formed into a heat transfer fluid flow path, and the heated fluid is supplied between the opposing wall surfaces (2), (2) of the compressor frame (1) [1 (3)
) and a large number of ceramic tubes (
5) is mounted on a rack 7 in parallel so that the ceramic tube (5) can expand and contract in the axial direction with a compression spring a41 cooled by the heated fluid supplied from the supply port (3). A heat exchanger characterized by: 2. Introducing the compression spring Q4) to the fluid to be heated.
(3) is provided inside the support 'i'i' (8) attached to the wall surface (2) so as to communicate with the ceramic pipe (5) through the support pipe (8) from the supply port (3). 8. The heat exchanger according to claim 7, wherein the heat exchanger is cooled by a fluid to be heated flowing through the heat exchanger. 3. Connect the compressed slab ring Q4 to the heated fluid supply port (3)
It is installed on the wall surface (2) so as to be in communication with the supply port (3) and connected to the support pipe (8), which is connected to the wall surface (2) (07).
The flow is diverted through 1-ri &-1. J+Words IeL4
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, -C, +b+=-C1 The heat exchanger according to claim 1.