JPS622478Y2 - - 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. The 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 in non-combustion converter exhaust gas treatment equipment, 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.

The present invention was developed to solve such problems, and provides an exhaust gas cooler that is easy to maintain, prevents dust from adhering to and accumulating on the contact heat transfer surface tube, and prevents the gas passage from being blocked. This is what I am trying to do.

An embodiment of the exhaust gas cooler according to the present invention will be explained in the case of hot water cooling with reference to FIGS. In the aisle
The contact heat transfer section 12 in the exhaust gas passage 11 is divided into several blocks, two blocks in this example, and the contact heat transfer surface tube of each block is a tube 14 with a center fin 13. The tubes 14 with center fins 13 are arranged in a grid pattern, and the contact heat transfer section 12 near the metallurgical furnace side
In this example, the pitch of the tubes 14 with center fins 13 in the lower contact heat transfer section 12 near the metallurgical furnace side is set to 300 mm, and the pitch of the tubes 14 with center fins 13 in the lower contact heat transfer section 12 near the metallurgical furnace side is increased to 300 mm. Tube 1 with center fin 13 of part 12
The pitch of 4 is 150mm.

A soot blower 6 for removing dust from the tube 14 with the center fin 13 is provided so as to be movable back and forth, penetrating the membrane water cooling wall 10 on one side in a direction orthogonal to the tube 14 with the center fin 13.

Next, another embodiment of the exhaust gas cooler of the present invention will be explained in the case of a boiler with reference to FIGS. Castable 16 on the surface
is stretched, and a water-cooled pipe wall 17 consisting of a separate tube is stretched close to its inner surface. The contact heat transfer section 12 in the exhaust gas passage 11 is divided into several blocks, three blocks in this example, and the contact heat transfer surface tube of each block is connected to the center fin 1.
3 tube 14. The tubes 14 with center fins 13 are arranged in a grid pattern, and the pitch of the tubes 14 with center fins 13 in the lower contact heat transfer section 12 near the metallurgical furnace side is 300 mm.
The pitch of the tubes 14 with center fins 13 in the middle contact heat transfer section 12 is 250 mm, and the pitch of the tubes 14 with center fins 13 in the upper contact heat transfer section 12 is 200 mm.

The tube 1 with the center fin 13 passes through the casing 15 and castable 16 on one side in the direction orthogonal to the tube 14 with the center fin 13.
4 soot blowers 6 for removing dust are provided so as to be movable forward and backward.

Note that the water cooling pipe wall 17 may be replaced with a water cooling pipe wall made of a tube with a center fin or a membrane water cooling wall.

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 gas passes through the exhaust gas passage 11, it is rectified by the tube 14 with the center fin 13, which is the contact heat transfer surface tube of each contact heat transfer section 12, and is rectified as shown in FIGS. 2c and 3b.
In addition, as the flow approaches the metallurgical furnace, the pitch of the tube 14 with the center fin 13 of the contact heat transfer section 12 is increased, so that the tube 14 with the center fin 13 is free of particles scattered from the metallurgical furnace. Adhesion and accumulation of gold, slag, dust, etc. are prevented, and the exhaust gas passage 11 is not blocked. In addition, non-combustible gas is handled by the center fin 1, which has a large contact surface.
Since the exhaust gas flows along the three-tube tube 14, the heat retained in the exhaust gas is efficiently absorbed, and the heat recovery rate is greatly improved.

Note that the soot blower 6, when a certain period of time has elapsed,
The tube 14 with the center fin 13 is moved forward and backward into the exhaust gas passage 11 and cleaned by blowing soot-blowing body gas.

Regarding the length of the center fin 13 in the tube 14 with the center fin 13, the longer the length, the better for preventing dust from adhering and accumulating and for absorbing the heat retained in the exhaust gas, but if it is too long, the temperature at the tip of the center fin 13 will rise. , the allowable stress of the material decreases, so the length is selected so that the allowable temperature is achieved. Generally, the length of the center fin 13 is preferably about 1/3 of the diameter of the tube 14.

Further, when the pitch of the tube 14 with the center fin 13 is set to 300 mm or more, there is no adhesion or accumulation of dust, so the soot blower 6 does not need to be provided.

Further, in the above embodiment, the contact heat transfer section 12 is divided into two blocks and three blocks, but the contact heat transfer section 12 may be divided into four blocks or five blocks. However, if it is divided into more than that, the number of tubes 14 with fins 13 in each block will decrease, and each time the flow of exhaust gas passes through each block, one tube with center fins 13 will be formed.
Since the flow changes by branching between the four, the perpendicular flow decreases and the rectifying effect of the tube 14 with the center fin 13 is lost.

As can be seen from the above explanation, the exhaust gas cooler in the non-combustion exhaust gas treatment device for a metallurgical furnace of the present invention divides the contact heat transfer section in the exhaust gas passage into 2 to 5 blocks.
The contact heat transfer surface tubes of each block are arranged in a grid pattern as center fin tubes, and the pitch of the center fin tubes of each block is gradually increased to 150 to 300 mm toward the metallurgical furnace, so contact heat transfer is achieved. It is more advantageous in terms of maintenance than conventional exhaust gas coolers with staggered surface tubes.
Moreover, the flow of the exhaust gas is rectified, and the accumulation of metal, slag, dust, etc. scattered from the metallurgical furnace is prevented, and the exhaust gas passage is not clogged. Furthermore, since the exhaust gas flows along the center fin tube with a large contact surface, the heat retained in the exhaust gas is efficiently absorbed, resulting in excellent effects such as a significant improvement in the heat recovery rate.

[Brief explanation of the drawing]

Figure 1a is a cross-sectional view of a conventional exhaust gas cooler in a non-combustion exhaust gas treatment device for a metallurgical furnace, and Figure 1b is a
Fig. 2c is a diagram showing the arrangement of the contact heat transfer surface tubes of the exhaust gas cooler, Fig. 2a is a cross-sectional view of an example of the exhaust gas cooler of the present invention, Fig. 2b is a longitudinal sectional view taken along line B-B in figure a, and figure c is a diagram showing the arrangement of the contact heat transfer surface tubes of the exhaust gas cooler.
FIG. 3a is a cross-sectional view showing another example of the exhaust gas cooler of the present invention, and FIG. 3b is a diagram showing the arrangement of the contact heat transfer surface tubes of the exhaust gas cooler. 10... Membrane water cooling wall, 11... Exhaust gas passage, 12... Contact heat transfer section, 13... Center fin, 14... Tube, 15... Casing, 1
6... castable, 17... water cooling pipe wall.

Claims (1)

[Scope of utility model registration request] In the exhaust gas cooler in the non-combustion exhaust gas treatment equipment of the metallurgical furnace, the contact heat transfer part of the exhaust gas cooler is
A metallurgy characterized by dividing the block into 5 blocks, making the contact heat transfer surface tube of each block a tube with a center fin, and gradually increasing the pitch of the center fin tube of each block to 150 to 300 mm toward the metallurgical furnace side. Exhaust gas cooler in non-combustion exhaust gas treatment equipment of furnace.