JPS6143200Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an exhaust gas cooler in a non-combustion exhaust gas treatment device for a metallurgical furnace.

Conventional exhaust gas coolers of this type are shown in Figure 1 a and b.
As shown in Fig. 1c, castables 2 are stretched over the inner peripheral surface of a casing 1 having a rectangular cross section, and contact heat transfer surface tubes of round tubes 4 are arranged in a staggered manner in the vertical direction in the exhaust gas passage 3 as shown in Fig. 1c. It is fixed by a support tube 5, and a soot blower 6 for removing dust from the contact heat transfer surface tube is movably provided on one surface in a direction perpendicular to the contact heat transfer surface tube.

However, in such an exhaust gas cooler, the contact heat transfer surface tubes are arranged in a staggered manner, which is good in terms of heat absorption, but disadvantageous in terms of maintenance. In addition, since the contact heat transfer surface tubes are composed of round tubes 4 in combination with the staggered arrangement, there is a lot of dust D deposited on the front and rear sides of the round tubes 4 relative to the exhaust gas flow, as shown in Fig. 1c. Contact heat transfer efficiency is low. Furthermore, since the pitch of the contact heat transfer surface tube was selected with reference to general waste heat boilers and combustion type converter waste heat boilers, it was not possible to suppress the adhesion and accumulation of dust D.

In addition, in a combustion type converter waste heat boiler, the dust in the exhaust gas is mainly composed of stable Fe ₂ O ₃ , so
In addition, since the dust content in the gas is low, the technology for adjusting the pitch of the contact heat transfer surface tube to prevent dust adhesion and accumulation has been established, but it is difficult to In this case, since the dust in the exhaust gas is mainly unstable FeO and Fe ₃ O ₄ , and the dust content in the gas is high, the pitch of the contact heat transfer surface tube must be adjusted to prevent dust from adhering and accumulating. At present, the technology for how to do this has not been established. In addition, in the above-mentioned exhaust gas cooler, the wall around the contact heat transfer surface tube is made of castable 2 or a combination of castable 2 and loose tube 7 shown in chain lines, so dust easily adheres to it, and once it starts, it grows rapidly. The contact heat transfer surface spreads into the tube,
This leads to the exhaust gas passage being blocked.

The present invention was developed to solve such problems, and is easy to maintain, prevents dust from adhering to and accumulating on the contact heat transfer surface tube and surrounding walls, and prevents gas passages from being blocked. The purpose is to provide a cooler.

An embodiment of the exhaust gas cooler according to the present invention will be described below with reference to FIGS. 2a, b, and c in the case of hot water cooling. Reference numeral 10 denotes a membrane water cooling wall around the exhaust gas cooler having a rectangular cross section; A tube 13 with a center fin 12 is arranged in a grid pattern as a contact heat transfer surface tube with a width of 150 to 300 mm and a height of 60 to 150 mm.
A soot blower 6 for removing dust from the contact heat transfer surface tube is arranged at a pitch of mm, and is movably provided so as to penetrate the membrane water cooling wall 10 on one side in a direction perpendicular to the contact heat transfer surface tube.

Next, another embodiment of the exhaust gas cooler of the present invention will be explained in the case of a boiler with reference to FIG. 1.
Reference numeral 5 denotes a casing around the outer circumference of the exhaust gas cooler having a rectangular cross section, and a castable 16 is stretched on the inner peripheral surface of the casing, and a water cooling pipe wall 17 made of a loose tube is stretched close to the inner surface of the castable. Exhaust gas passage 1
1, tubes 13 with center fins 12 are arranged as contact heat transfer surface tubes in a grid pattern with a pitch of 150 to 300 mm horizontally and 60 to 150 mm vertically, as in the previous embodiment, and the tubes 13 with center fins 12 are arranged in a grid pattern with a pitch of 150 to 300 mm horizontally and 60 to 150 mm vertically. A soot blower 6 for removing dust from the contact heat transfer surface tube is provided so as to be movable back and forth through the casing 15 and the castable 16.

The water-cooled pipe wall 17 around the exhaust gas cooler includes a water-cooled pipe wall 18 made of a tube with a center fin as shown in FIGS. 4 and 5, and a membrane water-cooled pipe wall 1.
It may be replaced with 9.

In each of the embodiments of the exhaust gas cooler of the present invention configured as described above, when the exhaust gas generated in the metallurgical furnace enters the exhaust gas cooler through the exhaust gas hood (not shown) without combustion, the When the combustion exhaust gas passes through the exhaust gas passage 11, it is rectified by the tube 13 with the center fin 12, which is a contact heat transfer surface tube, and flows as shown by the arrow in FIG.
Since the tube is made large to 300 mm and 60 to 150 mm in length, adhesion and accumulation of dust to the tube 13 with the center fin 12 is prevented. Further, since the non-combusted exhaust gas flows along the tube 13 with the center fin 12 having a large contact surface, the heat retained in the exhaust gas is efficiently absorbed, and the heat recovery rate is greatly improved. When the tubes with center fins are arranged in two rows as shown in FIG. 2d, a support 20 is inserted to support them. Further, since a membrane water-cooled wall 10 or a water-cooled pipe wall 17, 18, or 19 such as a loose tube, a center fin tube, or a membrane tube is provided around the exhaust gas cooler, the inner surface of the exhaust gas passage 11 is water-cooled, and therefore Dust does not adhere to the exhaust gas passage 11, and the exhaust gas passage 11 does not become clogged. Also, this water-cooled exhaust gas passage 1
Since the heat retained in the exhaust gas can be absorbed even on the inner surface of the exhaust gas, the heat recovery rate can be further improved.

However, after a certain period of time has elapsed, the soot blower 6 is moved back and forth into the exhaust gas passage 11, and the soot blowing medium gas is blown onto the tube 13 with the center fin 12, which is the contact heat transfer surface tube, to clean it. Therefore, there is no accumulation of dust on the tube 13 with the center fin 12.

In addition, the center fin 12 in the tube 13 with the center fin 12 which is a contact heat transfer surface tube
The longer the length, the better for preventing dust from adhering and accumulating, and for absorbing the heat retained in the exhaust gas. However, if it is too long, the temperature at the tip of the center fin 12 will rise and the allowable stress of the material will decrease, so the allowable temperature Select the length so that Generally, the length of the center fin 12 is preferably about 1/3 of the diameter of the tube 13.

In addition, if the pitch of the tube 13 with center fin 12, which is a contact heat transfer surface tube, is 300 mm or more, dust may adhere and accumulate in the exhaust gas passage 1.
Since the soot blower 1 does not become clogged, the soot blower 6 does not need to be provided.

As can be seen from the above explanation, the exhaust gas cooler in the non-combustion exhaust gas treatment equipment for metallurgical furnaces of the present invention has contact heat transfer surface tubes arranged in a checkerboard pattern, so that the contact heat transfer surface tubes are arranged in a checkerboard pattern. It is more maintenance friendly than hot surface tubes. In addition, since the contact heat transfer surface tubes are arranged in a grid pattern and a center finch tube is used, the flow of exhaust gas is rectified, preventing adhesion and accumulation on the duct, and eliminating the slightest amount of dust adhesion. It can be removed by periodically injecting soot-blowing medium gas with a soot blower. Furthermore, since the non-combusted exhaust gas flows along the center finch tube which has a large contact surface, the heat retained in the exhaust gas is efficiently absorbed, and the heat recovery rate is greatly improved. Furthermore, since the exhaust gas cooler is surrounded by a membrane water-cooled wall or water-cooled pipe wall, the inner surface of the exhaust gas passage is cooled and dust does not adhere and grow, preventing the exhaust gas passage from becoming blocked. effective.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional exhaust gas cooler in a non-combustion exhaust gas treatment device for a metallurgical furnace, Figure b is a vertical cross-sectional view taken along the line A-A in Figure A, and Figure c is a contact view of the exhaust gas cooler. Diagram showing the arrangement of heat transfer surface tubes, Figure 2a
1 is a cross-sectional view of an example of the exhaust gas cooler of the present invention, FIG.
d is a longitudinal cross-sectional view of another example of the exhaust gas cooler of the present invention, and FIGS. 3, 4, and 5 are cross-sectional views showing still other examples of the exhaust gas cooler of the present invention, respectively. . 10... Membrane water cooling wall, 11... Exhaust gas passage, 12... Center fin, 13... Tube, 15... Casing, 16... Castable, 17, 18, 19... Water cooling pipe wall, 20......
support.

Claims (1)

[Scope of utility model registration request] In an exhaust gas cooler in a non-combustion exhaust gas treatment device of a metallurgical furnace, the contact heat transfer surface tube of the exhaust gas cooler is a tube with a center fin, and the center fin tubes are arranged in a grid pattern and the pitch is 150 to 300 mm in width and 60 to 150 mm in height, the exhaust gas cooler is surrounded by a membrane water-cooled wall or water-cooled pipe wall, and the soot blower for dust removal of the center fin tube is installed on the wall so that it can move forward and backward. Exhaust gas cooler in non-combustion exhaust gas treatment equipment.