JPS6340790Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a water supply and drainage system for water-cooled panels, water-cooled jackets, water-cooled pipes, etc., referred to in this document as water-cooled panels, used under severe thermal conditions such as electric arc furnaces. It is something.

[Conventional technology]

For example, arc furnace steelmaking uses UH to improve productivity.
P. (Ultra-High Power) operation technology is becoming more widespread, and with this operating condition, the conditions for furnace refractories are becoming even more severe, forcing them to shorten their lifespans and increasing costs. In response to this, water-cooled panels are being used instead of refractories on furnace walls and furnace lids, and are currently extending the lifespan of the panels.
Technological improvements are being made to prevent heat dissipation inside the furnace and expand the area of use, and many companies have filed patents and utility models related to water-cooled panels. However, the water supply and drainage system has conventionally been constructed using a simple circuit in which a flow control valve 16 and pressure gauges 32, 34 are attached to the water supply and drainage path of the water cooling panel 4, as shown in FIG. -102206 Publication) and energy-saving circuits that effectively utilize panel return water (Electric Steel Vol. 54, No. 1, p. 51), but these circuits directly contribute to extending the lifespan and stability of water-cooled panels. It's not an idea. In the future, as the use of water-cooled panels for furnace walls, furnace covers, etc. becomes more widespread, the safety, reliability, and longevity of the water-cooled panel as a whole system including the water supply and drainage system will become more important. Let's become.

[Problem that the invention attempts to solve]

As mentioned above, replacing refractories with water-cooled panels as a cost reduction measure to address the shortened lifespan of refractories in high-productivity oriented arc furnaces is important as it extends lifespan, improves reliability, and takes safety measures against steam explosions. This is a challenge.

The purpose of this invention is to solve the above-mentioned problems by focusing on the water supply and drainage system of water-cooled panels.

[Means for solving problems]

The present invention provides a three-way switching valve on the water supply side of a water supply and drainage system for water-cooled panels, a two-way switching valve on the drainage side, and further includes switching means for each valve.
This makes it possible to flush the water-cooled panel, shut off the water supply by remote control in the event of an abnormality in the water-cooled panel, and simultaneously discharge water inside the panel.

FIG. 2 shows an embodiment of the present invention (a water supply and drainage system for a water-cooled panel for an electric furnace), and FIG. 1 shows an extracted main part of the embodiment. In these drawings, 4
is a water-cooled panel installed on the electric furnace side (the figure shows an example of a furnace wall), and depending on the furnace capacity, multiple panels are attached to the furnace wall 2 or furnace lid 3, and the water supply and drainage are self-circulating. ing. 7 is a tank, 8 is a water pump, 9 is a main water supply pipe, 9-1 is a water supply header pipe, 12 is a water supply branch pipe, 17 is a drainage branch pipe, and 24 is a drainage basin. 25 is a drainage main pipe, which is a flow path that returns to the tank 7 by gravity, and as shown in the piping diagram shown in FIG. -n are connected in parallel, and the A section is common. The drainage basin 24 is located at a high position, and the cooling water flows into the drainage basin 24 from the drainage branch pipe 17 in an open state, making it possible to measure each water temperature and visually observe the water volume. 11 is a water supply temperature detector, and 14 is a wastewater temperature detector from each of the water cooling panels 4. Based on the measured wastewater temperature, trends in water temperature, water volume, pressure, etc. of each panel 4 are managed and an alarm is issued. . Reference numeral 16 denotes a variable water flow rate adjustment valve, which is used to adjust the water volume of the water cooling panel 4 during normal times and to normalize the water volume by adjusting the water volume when the temperature of the drain water rises in trend management using the waste water temperature detector 14. Reference numeral 18 indicates a three-way switching valve, and reference numeral 19 indicates a two-way switching valve, which are remotely controllable valves, and this example shows an example of an air switching valve. The operation is performed by a changeover switch 30 on a changeover panel 26 as a changeover valve means, and each valve 18, 19 is used for operation (steady).
The water supply branch pipe 12 and drainage branch pipe 17 are connected to drain pipes 20-1 and 20-2 that connect the drain tank 21. 20-1 is a first drain pipe for flushing inside the water-cooled panel 4 and for urgently discharging water in the water-cooled panel, and 20-2 is a second drain pipe. 22 is a pump for the drainage tank 21, which drains wastewater through a pumping pipe 23.
Send to 4. 13 is a safety valve, and when the drainage branch pipe system becomes blocked due to an abnormality, the water cooling panel 4
This is to prevent explosions. 10,15
is a flow meter, 27 and 28 are air pipes, 29 is a three-way switching check valve, 31 is an air supply source, 32,
33 is a pressure gauge, and 34 and 35 are supply branch valves.

[Effect]

During normal operation, as shown by the bold line circuit in Figure 2, the changeover switch 30 is in the neutral state, and the cooling water in the tank 7 is distributed from the water pump 8 through the water supply pipe 9 to each of the water cooling panels 4-1 to 4-n. The sink passes through the drainage branch pipe 17, collects in the drainage basin 24, circulates by gravity from the drainage main pipe 25 to the tank 7, and then flows through the water cooling panel 4.
performs the cooling function. Meanwhile, water supply and drainage temperature detectors 11 and 14, and flow meter 1 are used to manage the water cooling panel.
0, 15 and water pressure gauges 32, 33, and if the control value is abnormal, the variable water amount adjustment valve 16 is used to adjust the overall water amount balance while checking.

Next, a description will be given of malathing for the purpose of cleaning deposits inside the water-cooled panel and extending the life and safety of the panel 4. One water cooling panel 4-1
In FIG. 3, which shows only one water-cooled panel as a representative, flushing is performed by selecting one of the water-cooled panels in order to secure a flow rate with the aim of cleaning at a high flow rate higher than the normal flow rate. In addition, in order to avoid pressure loss in devices such as the variable water flow control valve 16, a second drain pipe 20 is installed to reduce pressure loss.
-2 is used. In this case, the selector switch 30 is switched to the left position and the two-way selector valve 19 is utilized. The cooling water in the tank 7 passes through the water supply pipe 9 from the water supply pump 8, and high-velocity water flows through the selected water cooling panel 4-1, and the two-way switching valve 19 and the first
The water passes through the drain pipe 20-1 and flows into the drain tank 21, and then flows through the pump pipe 23, the drain basin 24, and the main drain pipe 25 to the tank 7 by the pump 22 operated by the tank water level gauge (shown in the figure). circulate,
The selected water-cooled panel 4-1 is subjected to high-speed cleaning flushing to clean the deposits inside the panel, thereby producing the effect of preventing deterioration over time and maintaining a new state for a long time.

The normal number of flushing times depends on water quality etc.
It may be done about once/(1 day to 1 week). The biggest factor in the occurrence of abnormal values during trend management mentioned above is increased pressure loss due to deposits inside the panels, so especially careful flushing should be done to ensure the amount of water supplied to the panels.

Next, emergency drainage performed when an abnormality occurs, such as water leakage from a water cooling panel, will be explained using the bold line circuit shown in FIG. When an abnormality is detected in the water cooling panel 4-1, the changeover switch 30 is switched to the right position and
The one-way switching valve 18 and the two-way switching valve 19 are switched.
Then, water is supplied from the water supply pump 8 to the three-way switching valve 1.
8. As a result, the water cooling panel 4-
At the same time, the remaining water in the pump 1 passes through the three-way switching valve 18 and flows into the drain tank 21 from the second drain pipe 20-2, and at the same time, the remaining water in the pumping pipe 17, etc. also flows through the two-way switching valve 19 and into the drain tank 21. Prevents water from entering the furnace and prevents major accidents. In this case, only the water cooling panel 4-1 becomes the main circuit, and the other circuits remain as the regular circuits shown in FIG.

In the above embodiment, the return water is allowed to flow naturally and is opened at the drainage basin 24, which eliminates the possibility of an increase in internal pressure in the water cooling panel 4, etc., and the safety valve 13 prevents blockage, vaporization, etc. in the water cooling panel 4. This double prevents explosions caused by In addition, although pumping pressure is required in this circuit, it has the advantage of being able to divert that amount to flushing pressure. Of course drainage 24
It is effective even in a closed circuit without a switch valve, and although in this embodiment each switching valve is operated remotely by air, the same effect can be obtained by electrical operation.

Further, the effect can be further amplified by using one or a combination of these circuits, and the manufacturing cost can be reduced.

[Effect of idea]

This invention has a high-speed flushing circuit for water-cooled panels and an emergency drainage circuit for water inside the water-cooled panels in case of an emergency.
By doing so, it is possible to maintain the longevity, stability and reliability of the water-cooled panel, and it is also possible to ensure safety.

Therefore, electric furnaces aimed at high productivity in the future
The water-cooled panel not only suppresses the cost increase of refractories associated with UHP conversion and makes UHP conversion itself possible, but also allows use in conventional low-power electric furnaces due to the long life of the water-cooled panel.

In addition, at present, when the effectiveness of water-cooled panels is common, full-scale water-cooled panels are being promoted. However, the present invention is also very effective as a safety measure.

In the future, if a means to detect extremely small amounts of water leaks due to cracks in water cooling panels is developed and available at low cost, this device will be even safer and its lifespan will be extended. For example, if an extremely small amount of water leakage can be detected based on the difference between the water supply flowmeter 10 and the drainage flowmeter 15, the effect can be even higher.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the main parts of an embodiment of a water supply and drainage system for an electric furnace water cooling panel according to the present invention;
FIG. 2 is a block diagram showing the entire system incorporating the water cooling panel water supply and drainage system shown in FIG. 1, and the arrows in FIGS. 1 and 2 indicate water flow during normal operation. Third
Figure 4 is a block diagram showing the water flow during flushing for one water-cooled panel in Figure 2, and Figure 4 is a block diagram showing the water flow during emergency drainage for one water-cooled panel in Figure 2. It is. FIG. 5 is a block diagram showing a conventional water supply and drainage system. 2... Furnace wall, 3... Furnace cover, 4... Water cooling panel,
7...Tank, 8...Water pump, 9...Water supply main pipe, 9-1...Water supply header pipe, 10...Flow meter for total amount of water supply, 11...Water supply temperature detector, 12...
... Water supply branch pipe, 13 ... Safety valve, 14 ... Drainage temperature detector, 15 ... Drainage branch pipe flow meter, 16 ... Variable water flow adjustment valve for drainage branch pipe, 17 ... Drainage branch pipe,
18...3-way switching valve, 19...2-way switching valve, 20
-1...First drain pipe, 20-2...Second drain pipe, 21...Drain tank, 22...Lifting pump,
23...Lifting pipe, 24...Drainage basin, 25...Drainage main pipe, 26...Switching panel, 27...2-way switching valve air piping, 28...3-way switching valve air piping, 32... Water supply pressure gauge, 33... Drainage branch pipe pressure gauge, 34, 35... Water supply main valve.

Claims (1)

[Scope of Claim for Utility Model Registration] (a) A water pipe configured to connect a plurality of water-cooled panels in parallel and supply cooling water from below to above the water-cooled panels; (b) A cooling water outlet of each water-cooled panel. (c) a second drain pipe connected to the cooling water inlet side of each water cooling panel via a three-way switching valve; ) Valve switching means for switching the two-way switching valve and the three-way switching valve for each water-cooled panel, A water cooling panel water supply and drainage device for a furnace, comprising: