JPS6140007B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling water circulation circuit of a converter exhaust gas treatment device, and in particular, effectively utilizes the heat retained in the cooling water that cools the skirt portion, and The present invention relates to a cooling water circulation circuit in which the circulation circuit is a sealed circuit and the cooling water circulation circuit for the entire converter exhaust gas treatment apparatus is made into a sealed circuit.

The high temperature gas generated from the converter is recovered after being cooled and dust removed. This gas has the danger of reacting with oxygen in the air and causing an explosion, and if it leaks outside, it poses a danger to the human body, so it must be disposed of in an airtight manner.

In order to maintain this airtightness, a skirt is provided between the furnace opening of the converter and the gas cooler to make it airtight. The converter is sealed with a skirt as described above while oxygen is being blown into the converter for refining (during blowing), and when the hot metal in the converter is taken out after refining (non-blowing). During refining), the skirt is lifted upwards to tilt the converter, and the hot metal inside the converter is taken out. In this way, the skirt moves up and down depending on whether it is being blown or not.

Conventionally, this type of cooling water circulation circuit has been shown in FIG. That is, in FIG. 1, the converter 17
The cooling water circulation circuit of the skirt 10 provided between the gas cooler 16 and the gas cooler 16 was constructed by providing a movable swivel joint 18 in the middle of the circulation circuit in order to enable the skirt 10 to move up and down. .

Since this swivel joint 18 is not pressure resistant, if the pressure of the cooling water is high, high temperature water will spray out from the movable part, which is dangerous. Therefore, the cooling water circulation circuit of the skirt 10 had to be open to the atmosphere.

That is, as shown in the figure, the cooling water sent from the cooling tower storage tank 22 to the cooling wall of the skirt 10 by the skirt cooling pump 9 is heated to the saturation temperature of the atmospheric pressure, and then transferred to the cooling tower which is open to the atmosphere. Cooled at 19,
This cooled cooling water was stored in a cooling tower storage tank 22 to constitute a cooling water circulation circuit for the skirt 10.

Further, when the cooling water is cooled in the cooling tower 19, a part of it is dissipated into the atmosphere as steam, and the amount consumed is replenished by the pump 21 from the storage tank 20.

On the other hand, the cooling water circulation circuit of the gas cooler 16 is sealed, and the cooling water that has been completely treated in the pure water tank 1 and the feed water deaerator 4 is used as the circulating water.

In this way, the cooling water circulation circuit of the exhaust gas treatment equipment is divided into two systems: the gas cooler (closed circuit using pretreated cooling water) and the skirt section (open circuit using unpretreated cooling water). I was familiar with the circuit.

As a result, in the cooling water circulation circuit of the skirt, the heat held in the cooling water is wastefully dissipated into the atmosphere by the cooling tower, and the cooling water is dissipated and consumed as steam into the atmosphere, resulting in a large amount of heat being dissipated into the atmosphere. This cooling water circulation system that handles cooling water has the disadvantage that the overall loss of heat and water is large. In addition, since the cooling water in the skirt section is not treated as part of the cooling water circulation circuit for the entire exhaust gas treatment system, it is difficult to control the overall water quality of the cooling water. The disadvantage is that the contained impurities adhere to the cooling wall of the skirt as scale, resulting in damage to the cooling wall of the skirt, or that the cooling wall of the skirt is corroded by oxygen in the cooling water. Ta.

The present invention aims to provide a cooling water circulation circuit for the entire converter exhaust gas treatment apparatus that solves all the conventional drawbacks as described above.

That is, the present invention provides a skirt tank in the cooling water circulation system of the skirt, connects the cooling water inlet and outlet of the skirt to the skirt tank to form a closed circuit, and provides a boiler drum in the cooling water circulation system of the gas cooler to prevent gas Connecting the cooling water inlet and outlet of the cooler to the boiler drum to form a closed circuit, and connecting the skirt tank and the boiler drum with a cooling water conduit to substantially connect the skirt cooling water circulation system and the cooling water circulation system of the gas cooler. The converter exhaust gas treatment apparatus is characterized in that the entire converter exhaust gas treatment apparatus has a sealed cooling water circulation circuit, and cooling water pretreated by a deaerator is supplied from the pure water tank to the skirt tank.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 2 shows an embodiment of the present application. In the figure, 7 is a skirt tank, and the cooling water inlet of the skirt 10 is connected to the skirt tank 7 by a conduit 8 via a skirt cooling water pump 9.
The cooling water outlet side of the skirt 10 is connected to the skirt tank 7 by a conduit 8', forming a closed cooling water circulation circuit of the skirt 10. In addition, 18 is the conduit 8, 8'
A swivel joint provided in the middle allows the skirt 10 to move up and down. 13 in the figure is a boiler drum, and the cooling water inlet side of the gas cooler 16 is connected to the boiler drum 13 via a conduit 15 having a boiler circulation pump 14;
The cooling water outlet side of the gas cooler 16 is connected to the boiler drum 13 by a conduit 15', thereby forming a closed cooling water circulation circuit of the gas cooler 16.

Next, the skirt tank 7 and boiler drum 13 are
A flow rate control valve 23 and a boiler feed pump 11 are connected through a conduit 12, respectively. By connecting the skirt tank 7 and the boiler drum 13, the cooling water circulation circuit of the skirt 10 including the skirt tank 7 and the cooling water circulation circuit of the gas cooler 16 including the boiler drum 13 are connected, and the entire converter exhaust gas treatment system is connected. It constitutes a sealed cooling water circulation system.

On the other hand, the cooling water supply system includes a pure water tank 1, a heat exchanger 3, and a deaerator 4.

That is, the pure water tank 1 and the heat exchanger 3 are connected via a conduit 5 equipped with a pure water supply pump 2, and the pure water outlet of the heat exchanger 3 is connected to the deaerator 4 via a conduit 5'. It is connected. Also, the pure water outlet of the deaerator 4 is
It is connected to the heat exchanger 3 via a conduit 6, and furthermore, the deaerated pure water outlet of the heat exchanger 3 and the skirt tank 7 are connected via a conduit 6' equipped with a skirt tank water level control valve 25. It constitutes a pure water supply system.

In the embodiment of the present invention configured as described above, pure water from which impurities (for example, silica, etc.) in the cooling water have been removed is stored in the pure water tank 1. This stored pure water is guided to a heat exchanger 3 by a pure water supply pump 2 to raise its temperature, and then guided to a deaerator 4.
The temperature is further raised by the steam from 27 and degassed (oxygen removed). The degassed high-temperature pure water is led to the heat exchanger 3, where it exchanges heat with the pure water to lower its temperature, and is then cooled by the skirt tank water level control valve 25.
into the skirt tank 7 at a flow rate regulated by.

The pure water, whose temperature has been lowered and degassed in the heat exchanger 3 and stored in the skirt tank 7 in this way, is supplied to the cooling wall of the skirt 10 by the skirt cooling pump 9, and then the purified water is The cooling water is
It is returned to the skirt tank 7 where the temperature has been raised within the skirt 10.

In this way, during the process in which the cooling water circulates from the cooling water supply system to the cooling water circulation circuit of the skirt 10, the heat balance of the cooling water is determined by the outlet temperature of the degassed pure water of the heat exchanger and the skirt tank 7. There is a certain correlation between the temperature of the cooling water stored in the skirt 10 and the temperature of the cooling water at the exit of the skirt 10, and the saturation pressure in the skirt is adjusted to a pressure that the swivel joint 18 can withstand. There is.

By the way, to explain using an actual numerical example, the pressure force that the swivel joint 18 can normally withstand is 4 to 5 kg/cm ² g, so it is necessary to adjust the pressure inside the skirt 10 to within that pressure.

Therefore, as a result of actually conducting the experiment assuming a certain model device, we found that the cooling water inlet temperature of the skirt 10 was 80℃~80℃.
If the temperature is 90℃ and the outlet temperature is 115℃ to 120℃, the saturation pressure inside the skirt 10 will be 4 to 5℃.
Kg/cm becomes ² g. In order to maintain this heat balance, the temperature of the cooling water in the skirt tank 7 must be set at 80°C or more.
Must be kept below 90℃. This temperature control is controlled by a skirt tank water level control valve 25.

In other words, in the steady state of this model device, cooling water is supplied to the skirt tank 7 by the skirt tank water level control valve 25 in an amount corresponding to the amount of steam taken out from the steam take-off valve 24 provided in the boiler drum 13. Then, if the outlet temperature of the degassed pure water of the heat exchanger 3 is set to 60°C, the temperature of the cooling water in the skirt tank 7 will be exactly 80°C to 90°C.
Further, the heat balance of the heat exchanger 3 is such that if water is supplied by the pure water supply pump 2 by the amount of water flowing through the flow rate control valve 25 described above, the degassed pure water outlet temperature of the heat exchanger 3 is In the case of 60℃, the pure water inlet temperature is 20℃ and the outlet temperature is 65℃. This 65°C pure water is heated by steam supplied from 27 in the deaerator 4, reaches 105°C, enters the heat exchanger 3, and its outlet temperature becomes exactly 60°C.

In other words, in this heat balance, when compared with the conventional circuit, the temperature of the pure water entering the deaerator 4 becomes 65°C from the conventional 20°C. i.e. 65℃−20℃
= 45°C advantageous. In addition, the temperature of the cooling water supplied to the boiler drum 13 was conventionally 105°C because it was directly supplied from the deaerator 4;
Since the internal temperature is 80°C to 90°C, the disadvantage is 15°C to 25°C. If you put all these advantages and disadvantages together, the result is 20℃~0
This means that ℃ heat has been recovered, and this amount of recovered heat corresponds to the amount of heat absorbed from the exhaust gas by the skirt.

On the other hand, the cooling water of the gas cooler 16 is supplied from the boiler drum 13 to the cooling wall of the gas cooler 16,
The temperature is raised in the gas cooler 16 and returned to the boiler drum 13 again. Further, water is supplied to the boiler drum 13 by the boiler feed water pump 11 in an amount equal to the amount of water consumed from the steam take-off valve 24 provided in the boiler drum 13.

As detailed above, according to the present invention, a skirt tank is provided in the skirt cooling water circulation system to form a sealed circuit, and a boiler drum is provided in the gas cooling system to form a sealed circuit, and the skirt tank and the boiler drum are connected to each other. By connecting with a conduit, the skirt cooling water circulation system and the gas cooler cooling water circulation system are essentially connected, and the cooling water circulation system of the entire exhaust gas treatment equipment is configured as a closed circuit, and the pure water from the pure water tank and By supplying the degassed pure water from the deaerator to the skirt tank after heat exchange, it is possible to make the skirt cooling water circulation circuit a closed circuit while maintaining the pressure resistance of the swivel joint. I can,
Heat recovery in the skirt portion can be achieved with high efficiency.

Moreover, there is no evaporative consumption of cooling water due to atmospheric evaporation, and the cooling water that has been pretreated in the pure water tank and deaerator is used as cooling water for the entire equipment, making water quality management easier and the skirt It has great effects, such as preventing scale adhesion to the cooling walls of the cooling wall, preventing damage to the cooling walls due to overheating, and further preventing corrosion due to oxygen in the cooling water.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a conventional cooling water circulation circuit, and FIG. 2 is a system diagram showing a cooling water circuit according to the present invention. 1...Pure water tank, 3...Heat exchanger, 4...Deaerator, 7...Skirt tank, 10...Skirt, 13...Boiler drum, 16...Gas cooler.

Claims (1)

[Claims] 1. In a converter exhaust gas treatment device that seals the space between the converter and the gas cooler with a skirt and guides the gas coming out of the converter to the gas cooler for cooling, a skirt tank is provided in the cooling water circulation system, and the skirt tank is The cooling water outlet and the cooling water inlet of the skirt are connected via a water supply pump, and the cooling water outlet of the skirt and the cooling water inlet of the skirt tank are connected to form a sealed cooling water circulation circuit of the skirt. Cooling water circulation in a gas cooler in which the cooling water outlet and the cooling water inlet of the gas cooler are connected via a boiler circulation pump, and the cooling water outlet of the gas cooler and the cooling water inlet of the boiler drum are connected and sealed. A circuit is connected, and a conduit for guiding cooling water from the skirt tank to the boiler drum is connected to exchange heat between the pure water and the deaerated pure water, and the deaerated pure water outlet of the heat exchanger is connected to the skirt tank. The cooling water circulation circuit of the converter exhaust gas treatment equipment that is connected to the