JPS6025719B2 - Kyupora - Google Patents

Description

[Detailed description of the invention] The present invention relates to a cupola.

Recently, from the standpoint of energy conservation, an increasing number of cupolas have been fitted with a heat exchanger in the bonito path section to utilize the heat in the exhaust gas to produce air for the feathers.

However, the installation area increases and it may be difficult to install it within a small factory. Furthermore, immediately after raw materials are introduced from the cupola charging port, the flame of combustion of carbon monoxide in the subtropical zone is extinguished, the temperature of the exhaust gas decreases, and then the combustion starts again. The exhaust gas temperature also rises repeatedly, and the temperature of the tuyere air preheated with such exhaust gas also fluctuates up and down, making it difficult to obtain products of uniform quality. was becoming difficult. The present invention was invented in view of this point, and the overall installation area of the cupola is reduced by 4.5 mm, making it possible to compactly install it in small factories, etc., and further preventing failures due to heat exposure of the heat exchanger. At the same time, the purpose is to keep the hot air temperature of the heat exchanger constant, thereby keeping the hot water temperature constant and making it possible to obtain products of uniform quality.

Therefore, the feature of the present invention is that a heat exchanger is installed coaxially with the furnace body and suspended via a suspension mechanism, and the hot air from the heat exchanger is A blow pipe is used to connect the air to the tuyeres, and a gap for hot air escape is formed between the upper end of the furnace body and the inner cylinder of the heat exchanger. C on the top surface of the metal near the entrance
An air supply hole for maintaining the temperature of the exhaust gas, which feeds air so that the pilot flame for burning O gas does not go out, is opened in the furnace wall at a height corresponding to the top surface of the metal, and immediately after the raw material is immersed through the charging port. The structure is such that the flame of the pilot flame does not go out. Hereinafter, the present invention will be explained in detail based on illustrated embodiments. In Fig. 1, reference numeral 1 denotes a furnace body made of a cylindrical steel plate lined with refractory bricks 2, and the furnace body 1 is mounted on a base plate 3.
．． The furnace body 1 is vertically supported, and a bag inlet 4 for feeding raw materials is opened near the upper end of the furnace body 1, and a bag inlet 4 for feeding raw materials is opened from the charging inlet 4 using a loading device consisting of a bucket, winch wire, etc. (not shown). Raw materials and coke are added.

A bottom door 5 is attached to the bottom of the furnace body 1 so as to be openable and closable.
7 is an outlet, and 7 is an outlet gutter. Primary tuyeres 8 are installed at predetermined circumferential intervals on the peripheral wall slightly above the outlet 6, and a wind box 9 and a tuyere conduit 101 are Tatsu-un is concluded. In the furnace body 1, the peripheral wall near the bottom of the charging port 4 is penetrated with air supply holes 11 for feeding the secondary air B at predetermined circumferential intervals. .

Figure 4 is an explanatory diagram of the classification names of the furnace height.
As shown in the cross-sectional view, the bed coke 12 is in the lower half of the furnace body 1, and the base metal 13 and additional coke 14 are in the upper half.
are mixed and piled up in each, resulting in the temperature distribution inside the furnace as shown in Figure 0. If classified according to the condition of the metal, from top to bottom, as shown in Figure M, they are divided into subtropical zone C, dissolution zone D, It can be divided into a superheat zone E and a pool zone F. On the other hand, the zone caused by the reaction between coke and furnace gas can be divided into a lower oxidation zone G and an upper reduction zone, as shown in FIG. This oxidation zone G
is the range from the position of the tuyere 8... to the middle of the bed coke 12, and the primary air sent from the tuyere □8... reacts with the coke 12, performing an oxidation reaction of C+02→C02, and the furnace The inner gas temperature is in a range where it becomes higher as it rises upward, and on the other hand, in the reduction zone, a part of the C02 gas generated in the oxidation zone G further reacts with coke, and the C02
A reduction reaction of 10C→XO takes place, and as an endothermic reaction, the temperature inside the furnace gradually decreases as it rises upwards, eventually forming a curve like 0 in the figure. By the way, as is clear from Figures 0 and 1, the temperature inside the furnace is low in the upper part of the child zone C, so in the conventional furnace structure, the above-mentioned reduction reaction cannot be carried out with only air from the charging port 4. The disadvantage of the conventional method is that the CO gas generated in the process is difficult to burn, and especially immediately after the raw material is introduced through the charging port 4, combustion is temporarily extinguished due to a decrease in the temperature inside the furnace and the blocking of air from the charging port 4. Met. In the present invention, an exhaust gas temperature maintenance air supply hole 11 for feeding secondary air B to the preheating zone C near the charging port 4 is opened, and the diamond inlet 4
The structure is such that the combustion flame of the CO gas does not go out immediately after the raw material is introduced. Because of this, C. 10 to 21C
. The flame of the second exothermic reaction is maintained and continued in the secondary zone C to efficiently heat the metal 13 etc. accumulated in the secondary zone C, and to reduce the exhaust gas temperature from the furnace body 1 to the upper bonito path. The temperature is also maintained at a relatively constant temperature at all times.

Furthermore, as is clear from FIG. 1, a heat exchanger 15 that utilizes the latent heat of the exhaust gas is continuously installed directly above the furnace body 1 as a so-called furnace system.

The heat exchanger 15 includes a cylindrical inner cylinder 16 which also serves as a bonito pipe, and a cylindrical outer cylinder 1 having a slightly larger diameter than the inner cylinder 16.
7, forming a cylindrical gap between both the inner and outer cylindrical bodies 16 and 17, and forming a heat exchange gap chamber 18 in which air flows from above to below to heat the space, and each of the upper and lower sides of the chamber 18 The annular air chambers 19 and 20 are arranged in a circular shape and project from the upper and lower parts of the inner cylindrical body 16 in a winding shape. Then, the lower end green portion 1 of the inner cylinder body 16
6a and the upper green portion la of the furnace body 1 are not directly fixed, and the weight of the inner cylinder 16, outer cylinder 17, etc. is held in a suspended manner by the suspension mechanism 21. . That is, in the illustrated example, the base frame 22 is fixed as a protrusion in the horizontal direction from or near the upper end line portion la of the furnace body 1, while the inner cylinder 1
A connecting frame 23 is fixed in a horizontal direction from the upper end of the connecting frame 23, and the connecting frame 23 and the base frame 22 are connected to a plurality of supports 24.
The suspension mechanism 21 is constructed by connecting the upper and lower parts together. A gap 25 with a predetermined distance dimension K is formed between the upper end wire portion la of the furnace body and the lower end green portion 16a of the suspended inner cylinder 16 to escape thermal expansion of the inner cylinder 16 as a heat transfer body. The gap 25 is closed from the outer circumferential side by an outer bale band 26. This circumscribed band body 26 has an upper end green portion la or a lower end green portion 16a.
It is attached to the outer drum so that it can be moved up and down to the other side. Further, a bellows part 27 is provided in the middle part of the outer cylinder body 17.
, and is configured to absorb the thermal expansion tension of the outer cylindrical body 17. 28 is a blower pipe for sending hot air in the annular cavity 20 of the upper heat exchanger 15 into the lower air box 9; 29 is a blower pipe for sending cold air from the main blower 30 to the annular cavity 19; It's a blower pipe.

In the end, the cold air sent from the main blower to the heat exchanger 15
The air flows sequentially through the empty chamber 19, the empty chamber 18, and the empty chamber 20, where it is heated, becomes hot air, and is sent from the blast pipe 28 to the wind box 9, and then from the air conduit 10... to the tuyere 8. ... reached,
It is blown into the inner bottom of the furnace body 1 and burns the coke.
By heating the air blown from the primary tuyere 8 in this way, the thermal efficiency of the cupola is improved, the amount of coke used as fuel is reduced, the melting rate is improved, and the quality of tapped hot water is improved. We are trying to In FIG. 1, cold air is blown into the furnace by another secondary blower 31, a blow pipe 32, and a tuyere conduit 33 into the exhaust gas temperature maintenance air supply hole 11.
The air sent from this exhaust gas temperature maintenance air supply hole 11 burns only the above-mentioned CO gas and is constantly held as a so-called pilot flame to preheat the metal and keep the exhaust gas temperature high and constant. , from the blast pipe 28 to the primary tuyere 8...
・It is also possible to keep the temperature of the hot air sent to constant. Next, in other embodiments shown in FIGS. 2 and 3, the structure of the upper heat exchanger 15 is almost the same as that of the previous embodiment and is given the same reference numeral, but the lower furnace body 1 has a unique structure, and in the part of the child zone C already explained in FIG. It consists of three base legs from the foundation floor.
The lower half moving part 35 is fixed to a frame body 36 held at a predetermined height and a trolley body 38 which is horizontally movable along rails 37, 37 fixed thereon.

The cart body 38 has wheels 39 and wheels 39 that move over the rails 37, 37.
..., and the lower half moving part 35 can be moved horizontally with a small force. Then, the upper closed end green of the lower half moving part 35 and the lower open □ end green of the upper half fixing part 34 are connected by a connecting bolt 40 consisting of bolt/nut connections and various locking mechanisms. It can be divided into two parts, and the upper and lower parts can be connected together. When one lower half movable section 35 corresponds to the upper fixing section 34, the other lower half movable section 35 is located on either the left or right side to repair refractory bricks, etc. in the furnace. Therefore, it can be said that one cupola serves as two subordinate cupolas. In addition,
The middle portions of the blower pipes 28 are connected by a removable connection 41, and are separated when the lower half moving section 35 moves.

Further, the lower half moving portion 35 is attached to the truck body 38 at its upper end, and most of the portion extends downward from the truck body 38 in a suspended manner, so that there is no risk of it running over. The upper half fixed part 34 is supported by a support frame 42 erected from the middle part of the frame 36, and as shown by solid lines in FIGS. 2 and 4, the upper half fixed part 34 is A base frame 22 is fixed to the base frame 22, struts 24 are erected thereon, and the heat exchanger 15 is suspended via the connecting frame 23. Of course, as shown by the imaginary line in the same figure,
It is also preferable that the pillars 24... or the base frame 22 be connected to and held by the support frame 42. Alternatively, although not shown, the supports 24 may be erected directly from the frame 36. Thus, the upper fixed part 34 is provided with a charging port 4, and an air supply hole 11 for maintaining the exhaust gas temperature for feeding secondary air B into the child zone C, and the raw material is supplied to the charging port 4.
The structure is such that the combustion flame of CO gas does not go out immediately after being immersed in it.

According to the effects of the embodiment shown in FIGS. 2 and 3, the flue, heat exchanger 15, raw material loading device, barrier device, etc. can be shared by a single unit, and a significant reduction in equipment costs can be achieved. . Furthermore, when entering the furnace during refractory brick repair in winter, air is not drawn upwards, so the so-called draft phenomenon does not occur, and the work is easier because it is not too cold. Furthermore, as is clear from the figure, the stand legs 3 are located at a distance from the furnace main body, making tapping and repair work extremely easy.
Of course, since it is possible to repair one of the lower moving parts 35 while the other is in use, continuous melting work is possible with one cupola. As described in detail above, the present invention sends secondary air B into the preheating zone C near the charging port 4 to prevent the combustion flame of CO gas in the upper part of the secondary zone C from being extinguished.
Even if the exhaust gas temperature is always constant, and a heat exchanger that utilizes the latent heat of the exhaust gas is installed, the temperature of the air supplied to the primary tuyere is maintained constant, reducing fluctuations in the temperature inside the furnace. , Therefore, the tapping temperature becomes uniform and a homogeneous product is obtained.

Furthermore, a heat exchanger 1 is installed coaxially right above the furnace body 1.
5, the installation area of the cupola does not increase, which is convenient for small factories.

Moreover, the exhaust gas temperature decreases little, and the temperature of the air flowing into the tuyere 8 in the heat exchanger 15 increases more reliably. In addition, the heat exchanger 15 is suspended directly above the furnace body 1 via the suspension mechanism 21, and a gap 25 for escape of thermal expansion is formed, so even after long-term use of the cupola, cracks etc. No worries at all and it has a long lifespan.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view showing one embodiment of the present invention, and FIG.
The figure is a partially sectional front view of another embodiment, FIG. 3 is a side view of the same,
FIG. 4 is a diagram showing the names of the furnace height sections to explain the inside of the furnace body. 4... Diamond inlet, 11... Air supply hole for exhaust gas temperature maintenance, 15... Heat exchanger, B...
...Secondary air, C...Preliminary zone. Figure 1 Figure 2 Figure 4 Ship

Claims (1)

[Claims] 1. A heat exchanger 15 is installed coaxially right above the furnace body 1 and suspended via a suspension mechanism 21,
The hot air from the heat exchanger 15 is connected to the tuyere 8 through a blower pipe 28, and a gap 25 for thermal expansion escape is provided.
, the upper end of the furnace body 1 and the inner cylindrical body 16 of the heat exchanger 15
Further, an air supply hole 11 for maintaining exhaust gas temperature is formed between the exhaust gas temperature retaining hole 11 for feeding air B so that the pilot flame for combustion of CO gas does not go out on the upper surface of the base metal near the charging port 4,
A cupola characterized in that it is opened in the furnace wall at a height corresponding to the vicinity of the upper surface of the metal so that the flame of the pilot flame does not go out immediately after raw material is introduced through the charging port 4.