JP5234578B2 - Water cooling duct - Google Patents

Description

  The present invention relates to a water cooling duct, for example, to an improvement in a water cooling duct used in a piping path of a system that directly sucks exhaust gas discharged from an electric furnace or the like and purifies it with a dust collector.

Conventionally, in a system in which high temperature exhaust gas including dust discharged from an electric furnace or the like is directly sucked, cooled to a predetermined temperature range, and purified by a dust collector, it is discharged from the electric furnace 1 as shown in FIG. A double structure (indicated by a broken line in FIG. 4) is adopted for the piping duct including the combustion tower 2 and the water cooling duct 3 through which the exhaust gas of about 1400 to 1500 ° C. is passed, and the cooling device 6 ( For example, the exhaust gas is cooled to 400 ° C. (preferably 250 ° C.) or less and is introduced into the dust collector 5 through the pipe 4 by circulating cooling water adjusted by a cooling tower or the like.
And the water cooling duct shown in FIGS. 5-6 is proposed as the water cooling duct 3 for cooling such high temperature waste gas to the range of predetermined temperature, and is utilized.
The water cooling duct 3 has a double structure of an inner cylinder 31 and an outer cylinder 32 which are cylindrical pipes, and cools exhaust gas passing through the inner cylinder 31 by flowing cooling water through the gap.

In this case, a water flow guide 33 is provided in the gap between the inner cylinder 31 and the outer cylinder 32 to form a flow path for circulating cooling water from the water supply port 3a to the drain port 3b. The heat of the exhaust gas transmitted from the surface is radiated to the cooling water side, and the inner cylinder 31 heated by the exhaust gas is cooled from the outer surface.
As shown in the development view of FIG. 6, the running water guide 33 flows the cooling water supplied from the water supply port 3 a from the lower side to the upper side in the drawing (in the assembled water cooling duct 3, the flow path R is (For example, it is configured to circulate 8 degrees so as to turn clockwise as viewed from the drain port 3b side. Hereinafter, the flow path R is divided into the flow paths a to h for each turn) And flow from upper left channel a to lower left channel a, then from b to b, ..., g to g, and finally from upper right h to lower right h and U-turn Then, it is divided into flowing cooling water and returned to the water tank W through the drainage port 3b.

  By the way, in the flow path R formed in the gap between the inner cylinder 31 and the outer cylinder 32 of the water cooling duct 3, a water supply port 3a communicating with the water supply header P and a drain port 3b connected to the water tank W are opened at both ends. If the temperature of the exhaust gas sent into the water cooling duct 3 is abnormally high, the cooling water supplied from the water supply port 3a is vaporized to reach the drain port 3b, and the cooling water is generated in the flow path. Insufficient cooling efficiency cannot be maintained, and the downstream inner cylinder 31 near the drain port 3b may be damaged by the vaporized cooling water.

  In view of the problems of the conventional water cooling duct, the present invention maintains a constant cooling efficiency even in the case of high-temperature exhaust gas, and prevents damage to the inner cylinder due to vaporized cooling water. An object is to provide a water-cooled duct that can be used.

In order to achieve the above object, the water cooling duct of the present invention comprises an inner cylinder and an outer cylinder, and circulates the cooling water sent from the water supply header in the gap between both cylinders from the water supply port to the drainage port. In a water-cooled duct provided with running water guides that form a flow channel that circulates while flowing, a branch port for branching the cooling water outside the system into the flow channel, and an auxiliary receiving the supply of cooling water from the water supply header separately from the water supply port characterized in that a water inlet.

In this case, a temperature measuring device for measuring the temperature of the cooling water branched from the branch port, a control mechanism for controlling the amount of water supplied to the auxiliary water supply port according to the value of the temperature measuring device, and the cooling water branched from the branch port. And a control mechanism for controlling the amount of.

According to the water cooling duct of the present invention, even when the exhaust gas temperature passing through the water cooling duct is abnormally high, the cooling water circulating around the flow path is replenished from the auxiliary water supply port, ensuring a sufficient amount of cooling water, and constant It is possible to provide a water cooling duct that can maintain the cooling efficiency of the inner cylinder and can prevent the inner cylinder from being damaged by the vaporized cooling water.

In addition, the control mechanism ensures a sufficient amount of cooling water, maintains a constant cooling efficiency, and when the cooling water is vaporized, without sending the vaporized cooling water to the drain of the water cooling duct, It is discharged out of the system from the branch port, and damage to the inner cylinder can be effectively prevented.

  Embodiments of a water cooling duct according to the present invention will be described below with reference to the drawings. In addition, about the structure similar to a conventional apparatus, the same code | symbol and a series of code | symbol are attached | subjected, and description is abbreviate | omitted.

1 to 3 show an embodiment of the water-cooled duct of the present invention.
This water-cooled duct 3 is for cooling the exhaust gas of about 1400 to 1500 ° C. discharged from the electric furnace 1 to 400 ° C. (preferably 250 ° C.) or less, as in the conventional example. After being processed by the above, it passes through the discharge pipe 5a as clean air and is discharged to the outside.

  The cooling water sent to the water cooling duct 3 is cooled from the water tank W by a cooling device 6 (for example, a cooling tower), and is fed into a gap between the inner cylinder 31 and the outer cylinder 32 from a water supply header P formed of a circulation pump through a water supply port 3a. The water is sent to the flow path R formed in the above, and after exchanging heat with the exhaust gas passing through the inside of the inner cylinder 31, it is returned to the water tank W through the drain port 3b.

On the outer peripheral surface of the inner cylinder 31 of the water cooling duct 3, a running water guide 33 that forms a flow path R that circulates while circulating the cooling water from the water supply port 3 a to the drain port 3 b at the same pitch as in the conventional example is arranged. Set up.
And in the flow path R, it branched from the branch port 34 which branches the cooling water outside the system, the auxiliary water supply port 35 which receives supply of cooling water from the water supply header P separately from the water supply port 3a, and A temperature measuring device 36 for measuring the temperature of the cooling water and a control mechanism 37 for controlling the amount of water supplied to the auxiliary water supply port 35 according to the value of the temperature measuring device are arranged.

The branch port 34 communicates with the branch pipe 38, joins the drain port 3 b, and is sent to the water tank W.
The number of the branch ports 34 is not particularly limited, and a plurality of branch ports 34 are preferably disposed at positions relatively close to the water supply port 3a. In this embodiment, an example in which four branch ports 34 are disposed is shown.

The auxiliary water supply port 35 is connected to the water supply header P through a valve V <b> 2 whose opening and closing is controlled by the control mechanism 37.
The number of auxiliary water supply ports 35 is not particularly limited, and a plurality of auxiliary water supply ports 35 are preferably disposed slightly downstream of the branch port 34. In this embodiment, the number of the auxiliary water supply ports 35 is the same as the four branch ports 34. Show.

A branch pipe 38 through which the branch port 34 communicates is provided with a temperature measuring device 36 composed of a thermocouple or the like for measuring the temperature of the cooling water branched from the branch port 34, and the cooling water branched from four locations in the figure. The temperature is measured and the measured value is transmitted to the control mechanism 37.
When the temperature of the cooling water exceeds the predetermined temperature range, the opening degree of the valve V2 is adjusted, and cooling water is additionally supplied into the flow path R of the water cooling duct 3 from the auxiliary water supply port 35. The temperature of the cooling water in the flow path R is lowered, and the valve V2 is closed when the temperature of the cooling water measured by the temperature measuring device 36 falls within a predetermined temperature range.
Further, as shown in FIG. 2, a valve V <b> 4 whose opening degree can be adjusted by the control mechanism 37 can be disposed between the water supply port 3 a and the water supply header P.
In this case, when the exhaust gas temperature passing through the water cooling duct 3 is low and the heat load is small, the amount of cooling water supplied into the water cooling duct 3 by the control mechanism 37 can be suppressed.

The branch pipe 38 branches a small amount of cooling water whose flow rate is adjusted by a valve V3 disposed in a bypass line L piped in parallel with the closed valve V1 from the flow path R, and is discharged from the drain port 3b. And the temperature of the cooling water branched by the temperature measuring device 36 is measured while being discharged to the water tank W.
The branch pipe 38 serves only to measure the temperature of the cooling water branched from the branch port 34 without using the valves V1 and V3 and the bypass line L, and closes the end. It doesn't matter.

The control mechanism 37 can adjust the opening degree of the valve V <b> 1 according to the value of the temperature measuring device 36 to control the amount of cooling water branched from the branch port 34.
As a result, the temperature of the cooling water measured by the temperature measuring device 36 is close to 100 ° C., and the cooling water branched from the branch port 34 is vaporized, that is, the cooling water in the flow path R is also When it is considered to be vaporized, the cooling water branched from the flow path R is added to the discharge from the bypass line L, and the valve V1 is opened to quickly and rapidly discharge the water into the water tank W. Can be prevented from being damaged.
In this case, the valve V2 is also fully opened, and cooling water is replenished into the flow path R from the auxiliary water supply port 35 to cool the exhaust gas.

As shown in the developed view of FIG. 3, the arrangement location of the branch port 34 and the auxiliary water supply port 35 is, for example, eight times around the water cooling duct 3 (the flow channel a to the flow channel h) as in the conventional example. ), The branch port 34 is disposed on the same axis as the drainage port 3b of the first to fourth rounds, and the auxiliary water supply port 35 is wrapped around the branch port 34 for the third to sixth rounds. On the same axis as the water supply port 3a (position shifted from the branch port 34 by 180 °).
As a result, even when the cooling water vaporized from the branch port 34 on the upstream side of the flow path R is forcibly discharged to the water tank W, locations where the cooling water does not flow in the flow path R can be reduced as much as possible. Insufficient cooling water in the flow path R can be compensated.

In this water-cooled duct, when the exhaust gas discharged from the electric furnace 1 passes through the water-cooled duct 3, heat is transferred from the inner surface to the outer surface of the inner cylinder 31, and heat is radiated from the flowing water guide 33 as in the conventional example. Cooled down.
Then, the cooling water supplied from the water supply header P to the flow path R through the water supply port 3 a is branched out of the system from the branch port 34, and the temperature is measured by the temperature measuring device 36.
When the measured temperature is within the predetermined temperature range, the cooling water is supplied only from the water supply port 3a and the passing flow rate is reduced to a small amount by the valve V3 arranged in the bypass line L. Continue to branch and discharge the cooling water from the branch port 34.

  When the temperature of the cooling water measured by the temperature measuring device 36 exceeds the predetermined temperature range, the opening degree of the valve V2 is adjusted by the control mechanism 37, and the cooling water is added into the flow path R from the auxiliary water supply port 35. To reduce the temperature of the cooling water.

  Further, when the temperature of the cooling water measured by the temperature measuring device 36 is measured at a temperature at which the cooling water near 100 ° C. is vaporized, the control mechanism 37 adjusts the opening degree of the valve V1 and the vaporized cooling water is supplied. It is possible to positively discharge the water tank W outside the system and prevent the inner cylinder 31 from being damaged.

  As mentioned above, although the water-cooled duct of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, The structure is suitably changed in the range which does not deviate from the meaning. It is something that can be done.

  The water cooling duct of the present invention is arranged in the cooling water flow path with a branch port for measuring the temperature of the cooling water and discharging the vaporized cooling water, and an auxiliary water supply port for the insufficient cooling water, Since it has the property of preventing damage to the inner cylinder due to vaporized cooling water, it can be used for a new electric furnace dust collection system, as well as a water cooling duct in an existing electric furnace dust collection system. It can also be used for alternative applications.

It is a general view of an electric furnace dust collection system using the water cooling duct of the present invention. It is a top view which shows one Example of the water cooling duct. It is an expanded view explaining the flow path of the water cooling duct. It is a general view of an electric furnace dust collection system using a conventional water cooling duct. It is a top view of the conventional water cooling duct. It is an expanded view explaining the flow path of the conventional water cooling duct.

Explanation of symbols

3 Water cooling duct 31 Inner cylinder 32 Outer cylinder 33 Flowing guide 34 Branch port 35 Auxiliary water supply port 36 Temperature measuring device 37 Control mechanism P Water supply header R Flow path

Claims (3)

A running water guide that forms a flow path that circulates while circulating the cooling water sent from the feed header from the feed port to the drain port is arranged in the gap between the two tubes. water cooling duct in a water-cooled duct, and a branch port for branching the cooling water outside the system in the flow path, characterized in that the water supply port and a separate auxiliary water inlet for receiving a supply of cooling water from the water supply header. 2. A temperature measuring device for measuring the temperature of the cooling water branched from the branch port, and a control mechanism for controlling the amount of water supplied to the auxiliary water supply port according to the value of the temperature measuring device. The water cooling duct described. A temperature measuring device for measuring the temperature of the cooling water branched from the branch port, and a control mechanism for controlling the amount of the cooling water branched from the branch port according to the value of the temperature measuring device. Item 2. A water-cooled duct according to Item 1.

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