JPS6142192B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling water circulation circuit that is open to the atmosphere for a metallurgical furnace exhaust gas treatment device, and in particular stores the heat retained in the cooling water and converts the intermittent fluctuations in the amount of heat retained in the cooling water into a constant amount of heat. This invention relates to a cooling water circulation circuit which makes the temperature of the cooling water at the inlet of the cooler constant and prevents the heat absorbed by the cooler from being wastefully dissipated by the heat of evaporation of the cooling water.

High-temperature gas generated from the metallurgical furnace is guided into a cooler, cooled, and collected after removing dust. The peripheral wall of the cooler is composed of a jacket or a water pipe, and the exhaust gas is cooled by cooling water circulating within the peripheral wall of the cooler.

Generally, metallurgical furnaces are operated intermittently. That is, there is a blowing time in which oxygen is blown into the metallurgical furnace for refining (hereinafter referred to as blowing), and a so-called non-blowing time in which the blowing of oxygen is stopped after the completion of refining and the molten steel is taken out from the metallurgical furnace. There is.

Therefore, a large amount of high-temperature gas is generated during blowing, but no gas is generated during non-blowing. Furthermore, even during blowing, the temperature and amount of gas generated fluctuate at the initial, peak, and final stages of blowing. Therefore, the amount of heat absorbed by the cooling water circulating in the cooler also fluctuates.

In order to effectively utilize the retained thermal energy of the cooling water, which varies with the intermittent operation of the metallurgical furnace, it is necessary to be able to extract a constant amount of thermal energy regardless of the intermittent operation of the metallurgical furnace.

Furthermore, the gas (CO) generated from metallurgical furnaces has the danger of explosion and is toxic to the human body, so safety is given top priority when designing coolers, etc. Therefore, due to the strength of the cooler, the pressure of the cooling water circulating inside the cooler must not be high, and the temperature can be kept constant by absorbing the radiant heat of the high-temperature gas in the form of a mixture of steam and water. In order to avoid applying thermal stress to the peripheral wall of the cooler, the cooling water circulation circuit is open to the atmosphere.

Conventionally, in such a cooling water circulation circuit that is open to the atmosphere, the thermal energy absorbed by the cooler is absorbed by the cooler as heat of evaporation and dissipated as steam to prevent the temperature of the cooling water circulating in the cooler from rising. Ta.

In this way, the thermal energy that had been dissipated into the atmosphere as heat of evaporation was wasted and was not utilized.

The present invention aims to provide a cooling water circulation circuit that is capable of extracting a constant amount of heat from the cooling water, which fluctuates intermittently, and also recovers the heat that was wasted as evaporative heat. .

That is, the present invention provides a metallurgical furnace cooling water circulation circuit, a heat storage circuit, and a heat utilization circuit, and switches between blowing and non-blowing by operating a valve, and the above three circuits are switched on during blowing. The thermal energy of the cooling water at the outlet of the cooler is absorbed by the heat storage circuit and the heat utilization circuit, eliminating evaporation of the cooling water within the cooler, and completely recovering the heat absorbed by the cooler. At the same time, during non-blowing, the metallurgical furnace cooling water circulation circuit, the heat storage circuit, and the heat utilization circuit are separated, and the thermal energy stored in the heat storage circuit is used by the heat utilization circuit, and the blowing It is characterized in that a certain amount of thermal energy can be used regardless of whether it is heated or not.

Hereinafter, details of the present invention will be explained with reference to an embodiment shown in the drawings. In the figure, gas generated in a metallurgical furnace 1 is cooled by a cooler 2, then removed by a dust remover (not shown), and recovered or diffused. The cooling water outlet side of the cooler 2 is connected to the steam/water separation tank 3 by a conduit 16 via a heat exchanger 34, and the inlet side thereof is connected to the steam/water separation tank 3 by conduits 17, 18, 19.
It is connected to the cooling water outlet side of the metallurgical furnace, forming a closed metallurgical furnace cooling water circulation circuit. A circulation pump 6 is disposed in the middle of the conduit on the cooler inlet side of the metallurgical furnace cooling water circulation circuit.

Next, reference numeral 4 denotes a heat storage device, the high temperature side of which is connected to the secondary side outlet of the heat exchanger 34 through a conduit 20, and the low temperature side connected to the secondary side outlet of the heat exchanger 34 of the heat storage circuit through conduits 24 and 25. It is connected to the side inlet and forms a closed heat storage circuit. In addition, 29 in the figure is a flow control valve, 35
is a temperature sensor. Further, 5 is a heat recovery device, the inlet side of which is connected to the high temperature side of the heat storage tank 4 through a conduit 22, and the outlet side thereof connected to the secondary side inlet conduit of the heat exchanger 34 of the heat storage circuit through a conduit 23. It is also connected by conduits 24, 25 to the low temperature side of the heat storage device 4 of the heat storage circuit. 7 in the diagram
is a hot water pump, 8 is a water supply pump, and each conduit 2
6 and 27, water can be supplied to the low temperature side of the heat storage device 4 and the steam/water separation tank 3. Also, 3
2 and 33 are check valves, 30 is a flow rate control valve, and 31 is a flow rate detector.

The operation of this embodiment configured as above will be explained below. First, during blowing, in response to a blowing start signal, the flow control valve 29 is opened so that the minimum amount of water flows, and the heat storage circuit and the heat utilization circuit are connected. High temperature gas generated from the metallurgical furnace 1 is cooled by a cooler 2. At this time, the cooling water circulating within the cooler 2 absorbs heat. The cooling water that has absorbed heat in this manner enters the primary side of the heat exchanger 34 via the conduit 16. The heat exchanger 34 gives heat to the secondary side cooling water of the heat storage circuit and enters the steam/water separation tank 3. The secondary cooling water that has absorbed heat in the heat exchanger 34 is transferred to the heat storage tank 4
flows into the high temperature side (upper part) of the In this way,
The high-temperature water that has flowed into the high-temperature side of the heat storage tank 4 is supplied to the heat recovery device 5 by the flow control valve 30, flow rate detector 31, and hot water pump 7 in the amount required for the heat recovery device, and the remaining high temperature water is Cooling water is stored in a heat storage tank 4. On the other hand, the low-temperature cooling water leaving the heat recovery device 5 joins with the cooling water on the low-temperature side of the heat storage tank 4,
It enters the secondary inlet of the heat exchanger 34.

In this way, during blowing, heat is stored in the heat storage tank 4 while the heat energy is utilized by the heat recovery device 5. Along with this, the temperature of the cooling water is lowered by the heat recovery device 5, and the heat energy is stored in the heat storage tank 4. merges with the low temperature side of
The cooling water enters the heat exchanger 34 and removes heat from the primary cooling water, thereby keeping the temperature of the cooling water entering the cooler 2 constant. Even if the amount and temperature of the gas generated from the metallurgical furnace 1 fluctuates during the initial, peak, and final stages of blowing,
Based on the signal from the temperature sensor 35, the flow rate control valve 29
The amount of cooling water is adjusted according to the change in the opening degree so that the temperature at the secondary outlet of the heat exchanger 34 is constant at 100°C.

Next, the non-blowing time will be explained. Upon completion of the blowing, the temperature of the temperature detector 5 decreases and the temperature control valve 29 closes. At this time, in the metallurgical furnace cooling water circulation circuit, the hot water stored in the steam/water separation tank 3 is guided into the cooler 2 by the circulation pump 6 and circulated therein. On the other hand, the hot water stored in the heat storage tank 4 is supplied to the heat recovery device 5 by the hot water pump 7, and the low-temperature cooling water that exits the heat recovery device 5 is transferred to the heat storage tank 4.
is returned to the lower temperature side. In this way, during non-blowing, the retained thermal energy of the cooling water stored in the heat storage tank 4 is utilized.

Therefore, the steam/water separation tank 3 and the heat storage tank 4
Since it is open to the atmosphere, some water vapor escapes into the atmosphere. Therefore, in order to replenish the water, a water supply pump 8 is used.
Water is supplied to each area by

As detailed above, according to the present invention, a metallurgical furnace cooling water circulation circuit, a heat storage circuit, and a heat utilization circuit are provided, and the metallurgical furnace cooling water circulation circuit is used to communicate with the heat storage circuit and the heat utilization circuit by valve operation. This allows the heat retained in the cooling water to be extracted continuously, regardless of whether blowing is in progress or not. By keeping the temperature constant, it is possible to prevent the cooling water from evaporating in the steam/water separation tank, and all of the heat dissipated by the heat of evaporation can be recovered by the heat utilization equipment and heat storage tank. The effect is extremely significant, as it eliminates pressure rises and cooling water temperature rises due to the strength of the cooler, prevents thermal fatigue caused by thermal stress, and improves safety. .

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of the present invention, which is simplified by a flowchart. 1... Metallurgical furnace, 2... Cooler, 3... Steam/water separation tank, 4... Heat storage tank, 5... Heat recovery device,
6... Circulation pump, 7... Hot water pump, 8... Water supply pump.

Claims (1)

[Claims] 1. A mixture of water vapor and saturated water discharged from the metallurgical furnace gas cooler is led to a steam/water separation tank, and the saturated water accumulated in the steam/water separation tank is led back to the metallurgical furnace gas cooler via the circulation pump. A heat exchanger is connected between the metallurgical furnace cooling water circulation circuit, the gas cooler and the steam-water separation tank of the metallurgical furnace cooling water circulation circuit, and the low temperature side of the heat storage tank is connected to the secondary inlet side of the heat exchanger. A heat storage circuit is connected from the secondary outlet side of the heat exchanger to the high temperature side of the heat storage tank, and the high temperature side of the heat storage tank and the inlet side of the heat recovery device of the heat storage circuit are connected to a conduit via a hot water pump. and a heat utilization circuit, in which the outlet side of the heat recovery device is connected to the low temperature side of the heat storage tank of the heat storage circuit, respectively, and during blowing in the metallurgical furnace, heat is stored in the heat storage circuit and the heat utilization circuit. At the same time, the heat energy is recovered from the air, and the heat amount of the cooler cooling water is absorbed, and during non-blowing, the heat energy stored in the heat storage tank is used, and in this way, the valve can be operated to switch between blowing and non-blowing. A cooling water circulation circuit for a metallurgical furnace exhaust gas treatment equipment.