JPS60165493A - Air heat exchanger - Google Patents

Abstract

PURPOSE:To prevent the leakage of air between the outer peripheral surface of heat transfer tube and the penetrating hole of a double wall by a method wherein the space between the double wall of the main body of heat exchanger is filled with heat resistant particles such as sand or the like, in the multitube heat exchanger, especially an air preheater utilizing high-temperature waste gas. CONSTITUTION:Multitude of tubes 1 are incorporated into a waste gas chamber 12, through which the high-temperature waste gas passes, and the tubes 1 are heated to a high temperature by the waste gas. On the other hand, low-temperature air to be preheated is sent into the tubes 1 by a fan from a distributing chamber 10 to heat it and is collected into a collecting chamber 11, further, is sent into the combustion chamber of a boiler. The space 4 between the wall 2 and the wall 3 is filled with sand or fine grain or the like and the thickness of the layer of sand is determined so as to be the several times of the diameters of the tubes, whereby the passing of air may be precluded.

Description

[Detailed Description of the Invention] In conventional polyphosphorous heat exchangers, especially in air preheaters that utilize high-temperature waste gas, metal tubes are usually used as heat transfer tubes, and they are fixed to the wall by Fi welding. In other cases, as shown in FIGS. 6 and 7, a heat-resistant gasket 15 is pressed against the outer part of the tube 1 using a gasket presser 16 to seal it. In particular, when an inorganic material such as glass or ceramic is used as a heat transfer tube, sealing with this heat-resistant packing 15 is usual.

However, the selection of the material for this heat-resistant packing 15 is questionable in order to compensate for the 0J of movement caused by the expansion and contraction of the tube due to the tension of the heat IFG, and if the shape is small in cross-section, it cannot withstand use for a short period of time. Also, since this heat-resistant packing 15 is held down by the bolt 17 using the packing press 16, the required area becomes large, and therefore, the distance between the pipes must also be made relatively large. Therefore, the main body of the heat exchanger is large.The heat exchanger holder 16 and the bolt 17 are not water resistant and therefore need to be expensive.

According to the present invention, by arranging a large number of tubes 1 at small intervals, it is not only possible to make the heat exchanger main body small, but also because the Alti structure is 1 to 11 units, manufacturing costs can be significantly reduced. The walls of the heat exchanger main body are made into double walls 2 and 3, and the space 4 between them is filled with heat-resistant particles such as sand, so that the heat is transferred to the outside of the tube 1 and the double walls 2 and 3. The first air heat exchanger has a structure that prevents leakage of air between the through holes 5 and 6 of the
Figures 2 and 2 show the case of air preheating using waste gas at temperature I1 as 14+l+ of the present invention, in which there are many lights 1 in the waste gas chamber 12 through which high-temperature waste gas passes. installed, the tube 1 is heated to a high temperature by the waste gas. On the other hand, 1 liter of air to be preheated is sent from the distribution chamber 1o into the pipe 1 by the blower, heated, collected in the collection chamber 11, and further sent to the combustion chamber of the boiler. In this process, pressurized cold air tends to leak into the waste gas chamber 12 through the gaps 11) 1 between the through holes 5 and 6 in the walls 2 and 3 and the outer circumferential surface of the tube 1. By filling the space 4 between the walls 2 and 3 with fine sand, etc., the space 4 is divided into micro air spaces formed by countless sand particles, and the pressurized air flows out. The pressure is reduced by the labyrinth fruit.

Therefore, by making the thickness of the sand layer several times that of the pipe 1←, the passage of air can be blocked. In addition, if it is particularly necessary to increase the pressure of the blower, an additional wall 7 is installed between the double walls 2 and 3 to form a triple wall, and the space 8 on the high temperature side is filled with heat-resistant particles such as sand. After filling the space 9 on the low temperature side with fine particles of sand, etc., it is moistened with a heat-resistant liquid such as oil or water to make it airtight.
It is possible to increase the temperature.

In the present invention, since the shape of the tube 1 is very simple, glass, ceramic, etc. can be used in addition to heat-resistant metals as the tube material.

Since the outward sealing method of the tube 1 is simple and can accommodate thermal expansion and contraction of the tube 1, assembly and disassembly of the entire heat exchanger is extremely easy. When using glass or ceramic as the tube 1, the heat conduction is inferior to that of fully shrunk materials, so in order to compensate for this, a thin metal tube 13 with heat dissipation protrusions 14 on the inner periphery is attached to the inner periphery of the tube 1. By sandwiching them so that they touch each other, it is possible to increase the contact area with low-temperature air and improve the efficiency of heat exchange.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of the double wall according to the present invention, Fig. 2 is an x-x rgj plane view thereof, Fig. 3 is a longitudinal cross-section of the triple wall case V1, and Fig. 4 is a protrusion for radiation V~. Fig. 5 is a side view of the heat exchanger tube, Fig. 6 is a longitudinal sectional view showing the conventional mounting method, and Fig. 7 is a side view of the heat exchanger tube. be. 1... Heat exchanger tube 2 and 2'...
...Walls 3 and 3' on the high temperature side...Walls 4 and 4' on the low temperature side...Space 5 between the double walls
and 5'...92 through holes 6 and 6'.
・・・・・・・・・? 3 through holes 7 and 7'...
... Intermediate walls 8 and 8'... Spaces 9 and 9' on the high temperature side of the triple wall... Space 10 on the low temperature side of the triple wall.
・・・・・・Preheated air distribution room 11・・・・・・・
... Preheated air collection chamber 12 ... High temperature filled gas chamber 13 ... Thin walled metal tube 14 ...
... Heat dissipation protrusion 1/l of the same material Applicant: Ryozo Ota; 5. ] Q 〆′ pierce 1 figure X × air 3r53 v2 eyes $811! l Fig. r L Tei / IJ / f d ・Math 6 Fig. 7

Claims (1)

[Claims] 1) Double walls 2 and 3 in a multi-tubular air heat exchanger
By filling the space 4 between them with heat-resistant particles such as sand, air leakage between the outer peripheral surface of the heat exchanger tube 1 and the double walls 2 and 30 through holes 5 and 6 can be prevented. air heat exchanger. 2) Another wall 7 is provided between the double walls 2 and 3, and the air 8 on the high temperature side is filled with heat-resistant particles such as sand, and the space 9 on the low-temperature side is filled with heat-resistant particles such as sand. The air heat exchanger according to claim 1, wherein after filling the particles, the particles are moistened with a heat-resistant liquid to make them airtight. 3) Gold n (thin-walled tube 1) with a purposeful protrusion 14 on the inner periphery.
Patent I7 in which heat conduction is improved by suppressing heat exchanger 3 so as to be in contact with the inner periphery of an inorganic heat exchanger tube 1;