JPS6111505A - Uniform distributor for gas current containing dust in boiler - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a device for evenly distributing a dust-containing gas flow at the boiler inlet in an exhaust heat recovery boiler such as a boiler attached to a coke dry extinguishing equipment. be.

(Prior Art) In an exhaust heat recovery boiler such as a boiler attached to a coke dry fire extinguishing facility (CDQ), wear problems of boiler tubes often occur due to dust in the gas.

In this type of boiler, gas drift and dust segregation within the boiler are unavoidable due to the gas flue or boiler structure, and local wear of the tubes within the boiler due to these gas drift and dust segregation is inevitable. arise. This local wear can be significantly reduced if there is no uneven flow of gas or segregation of dust, and troubles caused by local wear of the boiler tube can be prevented.

for that,? A collision inertia type dust catcher or the like is installed before the input to remove coarse-grained dust, but this method cannot completely remove even small-grained dust. 1. Since the gas temperature is high, it is not economical to install a dust catcher that guarantees high performance.

Therefore, in the case of a dust catcher according to this method, gas drift and dust segregation at the boiler inlet inevitably occur due to the shape of the dust catcher at the boiler inlet and the shape of the flue following it.

As a device for preventing gas drift inside a boiler, it is known to provide a rectifying plate at a portion where a gas passage largely changes direction.

For example, ``Steam Boiler'' by Ichimatsu Tanishita et al.
-5) Each of the figures in Kyoritsu Shuppan P, 207-209, 251 shows a boiler in which a rectifying plate is provided in the flue such as the outlet of the boiler combustion chamber.

This can be simply illustrated as shown in FIG. r-in front flue 5
The dust-containing gas entering the boiler 7 is guided by a rectifying plate 11 provided at the boiler inlet, passes through 4 groups of boiler tubes arranged on the stay 12, and exchanges heat with steam or canned water in the boiler tube 4. It is then discharged outside the boiler.

Especially when the gas temperature is high, it is difficult to install these current plates 11 due to heat resistance problems. Moreover, if the boiler wall is composed of water-cooled pipes, the installation becomes even more difficult.

Furthermore, in the case of exhaust heat recovery boilers such as CDQ, the gas temperature at the boiler inlet is as high as 800 to 1,000°C, and the dust content, which is mainly composed of coke fine powder, in the gas is 8 to 12,117 Nm.
Third, the installation of the rectifying plate 11 is becoming increasingly difficult due to the problem of wear.

On the other hand, in the case of a boiler with a structure in which the boiler tube is supported by both tubes, there is a technique that simply protects both tubes. This is shown in FIG. The figure is a front view of the boiler inlet.

In this case, ceramic protectors 9 are attached to both tubes 2 suspending the boiler tube 4 disposed in the boiler 7 and have the same shape. Therefore, the air gap 1 between both tubes 2
0 is also a rectangular shape with evenly spaced gaps.

Therefore, when there is uneven flow or dust segregation in the gas flow, these ceramic protectors 9 do not have the function of uniformly distributing the gas flow, and the gas flow and duct segregation occur *-
! There is a disadvantage that the gas flow contacts the boiler tube 4 and causes local wear of the intube 40.

(Problems to be solved by the invention) In order to solve the problems of the prior art as described above, the present invention has the following points:
This measures the uniform distribution of dust-containing gas flow at the boiler inlet to prevent local wear of the boiler tube.

(Means for Solving the Problems) The present invention provides an outer shape of a protector that protects a boiler tube at the inlet of a hanging tube boiler that exchanges heat with dust-containing gas.
This is a device for evenly distributing dust-containing gas flow in a boiler that becomes relatively smaller from the ceiling to the bottom.

As a result, the gas passage becomes smaller as it approaches the ceiling of the boiler, and conversely, the gap becomes larger as it approaches the bottom, and dust-containing gas flows into the gas passage below the boiler ceiling, where there is less air resistance. be guided.

Therefore, concentration of the dust-containing gas flow near the furnace wall on the return port side of the boiler is prevented, and dust segregation is also equalized.

(Example) An example of the present invention will be described in detail using the drawings. 1st
The figure is a front view of the boiler inlet, and FIG. 2 is a side view of the boiler inlet.

High-temperature dust-containing gas entering from the inlet flue 6 of the boiler 7 collides and reverses in the dust catcher 1 to remove coarse dust, and then enters the boiler 7 through the boiler inlet flue 5.

In the dirough, a boiler tube 4 is suspended from the boiler ceiling by both tubes 2, and high-temperature gas? Iratube 4
It is cooled by exchanging heat with the steam inside or boiler water. A ceramic protector 3, which is a heat-resistant and wear-resistant material, is attached to both tubes 2 for the purpose of protecting them.

In this embodiment, the shape of the ceramic protector 3 is gradually reduced from the ceiling to the bottom, so that the resistance of the gas passage 8 is reduced from the ceiling to the bottom, and the dust-containing gas is removed from the flue. The uniform distribution of the dust flow was measured by guiding it to the bottom.

In this embodiment, the outer shape of the protector 3 is gradually reduced from the ceiling to the lower part for all the hanging pipes 2, but even if it is applied to the hanging pipe of the boiler 7 port, the immersion port will become smaller. It is also effective to narrow the gas passages toward the sides.

In addition, the shape of the protector is an inverted truncated pyramid or an inverted truncated cone,
It can also be made smaller continuously from the ceiling to the bottom.

(Effects of the Invention) The present invention utilizes a hanging pipe of a boiler tube and changes the cross-sectional shape of the gas passage formed by a ceramic protector attached to the hanging pipe, thereby preventing deviation of the gas flow and rectifying the gas flow. Effect: 11, enemy double drop
19...stay.

This has the effect of improving the uneven flow of gas and the segregation of dust that come into contact with the tube on the downstream side.

Therefore, by eliminating or significantly reducing the protectors installed on the downstream tubes, it is possible to simplify the boiler structure, extend the tube life, and significantly improve the stability of the equipment. becomes.

[Brief explanation of drawings]

Fig. 1 is a front view of the boiler inlet and a sectional view taken along line A-A in Fig. 2, a side view of the boiler inlet, and Fig. 3 is a side view of the boiler inlet. Figure 4 shows a conventional method in which a rectifying plate is provided at the inlet, and Figure 4 shows a conventional method in which a protector of the same shape is attached to a hanging pipe.

Claims (4)

[Claims] (1) In a boiler that exchanges heat with dust-containing gas and a boiler tube supported by a hanging pipe, the outer shape of the protector that protects the hanging pipe of the boiler tube is made relatively smaller from the boiler ceiling to the bottom. A device for evenly distributing dust-containing gas flow in a boiler. (2) The device for evenly distributing a dust-containing gas flow in a boiler according to claim 1, wherein all of the hanging pipes are equipped with the protector. (3) The device for evenly distributing a dust-containing gas flow in a boiler according to claim 1, wherein the protector is attached only to the hanging pipe at the inlet of the boiler. (4) In the hanging pipe of the boiler, the outer shape of the protector is increased from the inlet to the counter-inlet side. Gas flow even distribution device.