JPH0538031Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is aimed at reducing _NOx ,
This invention relates to a heat retention device for hot blast furnace iron skin to prevent low-temperature corrosion cracking and heat cracks caused by SX _X.

[Conventional technology]

Damage to the hot blast furnace shell is included in the combustion exhaust gas.
Because low-temperature corrosion cracking occurs due to NO _X and _SX

However, hot air stoves are subject to changes in operating conditions and weather conditions.
Furthermore, due to deterioration of the lining material, the temperature of the iron skin may rise significantly and heat cracks may occur.

In order to prevent the occurrence of low-temperature corrosion cracking and heat cracking, it is generally known to maintain the hot blast furnace shell within a temperature range of 200±50°C.

For example, there is a proposal in Japanese Utility Model Publication No. 57-184345 as a heat retention device to realize this, and this is
This will be explained with reference to FIGS.

A heat insulating device is provided around the outer periphery of the hot blast stove iron shell 1, in which a rectangular exterior iron plate 2 made of stainless steel or the like is fixedly supported by upper and lower support frames 10 with a gap 3 of about 100 mm.
A cutout lid 4 that can be opened and closed in a vertical direction with respect to the hot blast furnace shell 1 is provided at the bottom of the exterior iron plate 2.
When the temperature of the hot blast furnace shell 1 rises to 250°C or higher,
This notch cover 4 is opened (pulled open in the direction of arrow A in FIG. 4) to form an opening. Through this opening, outside air is allowed to flow into the gap 3 between the hot-blast stove shell 1 and the exterior iron plate 2, thereby cooling the hot-blast stove shell 1.

On the other hand, when the temperature of the hot air stove shell 1 falls below 150°C, the open notch cover 4 is pushed in the opposite direction (direction of arrow B) to close it and keep warm.

[The problem that the idea attempts to solve]

The temperature of the hot stove shell 1 constantly fluctuates due to changes in outside air temperature and operational changes, but if it exceeds the control temperature of 200±50℃, open and close the notch cover 4 each time to keep it within the control temperature range. need to be controlled.

However, since this notch lid 4 is bent and opened beyond the plastic deformation point in the direction of arrow A in FIG. 4 as described above, when the notch lid 4 is closed, it is difficult to return to the original closed state. The heat retention effect deteriorates,
After repeating this several times, it broke and had to be replaced with a new exterior iron plate 2.

In addition, since there is no overlap between the left and right ends of the cutout lid 4, rainwater easily enters through these openings during rainy weather, causing the temperature of the hot air stove shell 1 to drop dramatically and the heat retaining effect to be completely lost. In addition, if a heat insulating material is used in the gap, the heat insulating material will become wet with rainwater, leading to problems such as accelerated corrosion and deterioration of the surface of the steel shell.

The object of the present invention is to provide a heat retaining device for a hot blast furnace shell that solves the above-mentioned problems.

[Means to solve the problem]

In order to solve the above-mentioned problems, the inventors of the present invention, as a result of various experiments and studies, decided to overlap the upper, lower, left and right ends of the exterior iron plate 2, and to make it possible to attach the exterior iron plate 2 in a louver shape so that it can be opened and closed freely. It has been found that it is possible to prevent rainwater from entering during the cooling process without damaging the exterior iron plate 2.

The present invention was developed based on this knowledge, and its characteristic feature is that the hot-blast blast furnace shell is covered with a plurality of exterior iron plates with a predetermined gap around the outer periphery of the hot-blast blast furnace shell. In the heat retention device, the hot-blast stove or a beam installed on the hot-blast stove is erected by penetrating the corner of an exterior iron plate that is arranged around the outer periphery of the hot-blast stove so that its periphery overlaps vertically, horizontally, and vertically. long bolt and
This is a heat insulating device for a hot blast furnace iron shell, which has a nut screwed onto the long bolt with the exterior iron plate sandwiched between the upper and lower or left and right exterior iron plates so that the gap can be adjusted.

[Effect]

The operation of the present invention will be explained below with reference to FIGS. 1a and 1b.

Intrusion of rainwater is prevented by overlapping the upper, lower, left, and right ends of the rectangular exterior iron plate 2, and the overlapping distance may be about 30 mm to 70 mm.

Furthermore, in each of the overlapping exterior iron plates 2, a gap δ is provided between the lower end of the upper exterior iron plate 2a and the upper end of the lower exterior iron plate 2b, and the lower exterior iron plate 2
Each exterior iron plate 2 is tilted downward and fixed in position by long bolts 5 and nuts 6 so that a gap δ is provided between the upper end of the hot-blast furnace shell 1 and the upper end of the iron shell 1.

By adjusting the void δ, that is, the amount of openings, the temperature can be easily and effectively adjusted.

Outside air flows out and flows in from this gap δ to cool the hot stove shell 1.

According to experiments conducted by the inventors of the present invention, as shown in FIG.
It flows between the exterior iron plate 2 and the hot-blast stove shell 1, and removes the heat from the hot-blast stove shell 1.

However, it was found that when the diameter exceeds 60 mm, the cooling capacity of the hot stove shell 1 becomes saturated.

Therefore, the length of the long bolt 5 should be such that it can secure a gap δ of about 60 mm, or at most about 100 mm, between the upper, lower, left, and right exterior iron plates 2, and is suitable for maintenance and inspection work of the hot air stove. There is no obstacle.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1a and 1b.

Figures 1a and 1b show the heat retaining structure, Figure 1a is an external view, and Figure 1b is a side sectional view.

In the figure, reference numeral 2 denotes a rectangular exterior iron plate that covers the hot air stove iron skin 1 with a gap 3 of 100 mm, and the upper, lower, left, and right exterior iron plates 2 are overlapped with each other with an overlap margin of 30 mm. Further, within the gap 3, a heat insulating material 8 having a thickness of 25 mm is provided in contact with the hot air furnace shell 1. 5 is a length of 150 mm with one end fixed to the beam 9 provided on the hot blast furnace shell 1.
It is a long bolt of mm, and passes through the overlapping portions of the four corners of each exterior iron plate 2. Reference numeral 6 denotes a nut screwed onto the long bolt 5, and the long bolt 5 is fixed at a predetermined position with two nuts 6 screwed onto the front and back sides of the exterior iron plate 2.

7 is a thermometer fixed to the surface of the hot blast furnace shell 1.

Measure the temperature of the hot blast furnace shell 1 with this thermometer 7, and if the temperature is below 150°C, tighten the upper, lower, left and right exterior iron plates 2 with nuts 6 so that there are no gaps, but the temperature is 250°C or lower. If this happens, first loosen the nut 6, move the lower part of the upper exterior iron plate 2a toward the tip of the nut 6, and then fix the lower exterior iron plate 2a.
A gap δ is formed between the hot air furnace shell 1 and the upper end of the hot air furnace shell 1 to cool it.

This gap δ is determined by the temperature measured by the thermometer 7.

At this time, it is preferable to remove the heat insulating material 8 if the temperature of the hot air stove shell 1 is difficult to decrease.

Then, when the hot blast furnace shell 1 becomes below 150℃,
The nuts 6 are tightened, and the lower part of the exterior iron plate 2a is moved to the hot stove shell 1 side, and the lower part of the exterior iron plate 2a and the upper part of the exterior iron plate 2b are brought into contact to keep the hot stove iron shell 1 warm.

[Effects of the invention] The present invention does not require each cutout cover to be provided on the exterior steel plate as in the past, so the processing of the steel plate is easy, and the cost is 2 to 3 times that of the conventional cutout cover method. It has a certain level of cooling capacity and can easily, quickly and reliably control any part of the hot stove shell to 200 ± 50℃, and can also withstand fluctuations in the shell temperature due to aging, changes in outside temperature, operational changes, etc. This has the effect of significantly reducing maintenance and inspection work over a long period of time.

[Brief explanation of the drawing]

Figures 1a and b are diagrams showing an embodiment of the present invention, a is its external view, b is a side sectional view, and Figure 2 is a diagram showing the opening amount δ between the exterior shells and the amount of temperature change in the hot blast furnace shell. FIG. 3 is a plan view of a conventional exterior iron plate with an opening/closing lid, and FIG. 4 is a side sectional view of the same. 1 is the hot blast furnace shell, 2 is the exterior iron plate, 2a is the upper exterior iron plate, 2b is the lower exterior iron plate, 3 is the gap, 4
is a notched lid, 5 is a long bolt, 6 is a nut, 7 is a thermometer, 8 is a heat insulator, 9 is a beam, 10 is a support frame, and δ is a gap.

Claims (1)

[Scope of utility model registration request] In a thermal insulation device for a hot-blast furnace shell, the outer periphery of a hot-blast furnace shell is covered with a plurality of outer iron plates with a predetermined gap, the periphery of each of the plurality of outer iron plates is superimposed on the outer periphery of the hot-blast furnace shell. , long bolts erected on the hot-blast furnace shell or on beams installed on the steel shell penetrate the corners of the exterior iron plates so that the corners of each of the exterior iron plates are stacked so that the distance between them can be adjusted. A heat retaining device for a hot blast furnace iron shell, characterized in that a nut is screwed onto the long bolt with an iron plate interposed therebetween.