JP2003314993A - Coke oven gas cooling method and its device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a COG cooling method for controlling the temperature of COG to cause no deposition of naphthalene, depending on a change in COG generation amount and a change in cooling water temperature, and the temperature of cooling water to hardly cause high-temperature corrosion in cooling pipes. <P>SOLUTION: The cooling method using sea water for indirectly cooling the COG with a number of cooling pipes comprises controlling the flow rate of the cooling water flowing in the cooling pipes depending on the COG amount and the cooling water temperature and shielding part of the cooling pipes to control the heat exchanging area thereof so that the cooling temperature of the COG is a preset temperature or higher to cause no deposition of naphthalene and the outlet temperature of the cooling water is a preset temperature or lower to hardly cause the high-temperature corrosion. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coke oven gas (hereinafter, also simply referred to as COG) cooling method and cooling device used in the field of coal gas chemistry. More specifically, the coke oven gas can be cooled by appropriate cooling operation according to the change of the COG generation amount and the change of the seawater temperature due to the seasonal change when the seawater is used as the cooling water. The present invention relates to a COG cooling method and a cooling device for cooling.

[0002]

2. Description of the Related Art A COG cooling device is generally an indirect cooling type cooling device using a vertical multi-tube heat exchanger consisting of a large number of vertical tubes (cooling tubes), and consumes a large amount. Seawater is often used as the cooling water for economic reasons.

On the other hand, about 10 g of naphthalene is contained in the COG (80 to 85 ° C.) discharged from the dry main of the coke oven.
It contains Nm ³ . Therefore, in the indirect cooling type cooling device alone, the heat transfer area (heat transfer efficiency) decreases due to naphthalene or the like deposited in the COG cooling process of cooling to about 30 to 35 ° C., and periodic cleaning is required. Also, CO
The temperature of G and the saturated concentration of naphthalene are as shown in FIG. 8 (extracted from “Aromatic Handbook”), and the precipitation of naphthalene is extremely low up to around 50 to 60 ° C. Therefore, a combination with a direct cooling type cooling device has been created (see Fig. 7).
Therefore, a method of extending the cleaning cycle of the cooling device by increasing the cooling temperature of the cooling device of the indirect cooling system is used.

FIG. 7 is a schematic view of a general COG cooling device in which the cooling temperature of the indirect cooling type cooling device is raised by combining with the direct cooling type cooling device (see FIG. 7). Like the COG cooling device shown in FIG. 7, the COG coming out of the dry main of the coke oven at 80 to 85 ° C. enters the indirect cooling type cooling device 701.
The seawater used as the cooling water has a temperature of 50 to 6 so that the precipitation of naphthalene in COG is extremely low and the load on the direct cooling type cooling device 703 does not become large.
It is cooled to a temperature of 0 ° C. Thereafter, the COG discharged from the indirect cooling type cooling device enters the direct cooling type cooling tower 703 through a pipe, and is cooled to a temperature of 30 to 35 ° C. by spraying the circulating cooling water from the upper part of the tower. The COG emitted from the direct cooling type cooling tower 703 is sent to the COG refining process via the blower 705. On the other hand, from the viewpoint of effective use, seawater used as the cooling water of the indirect cooling type cooling device 701 is subjected to heat exchange with the circulating cooling water of the direct cooling type cooling tower 703 by a heat exchanger (HE) 707, and then indirectly cooled. System cooling device 701.

By combining with such a direct cooling type cooling device, the cleaning period can be extended.
As for the indirect cooling type cooling device of the OG, the amount of COG generated changes depending on the regular repair of the coke oven and the production amount of coke, and therefore it is necessary to operate the cooling device adapted to this. Moreover, since seawater is used as cooling water, the seawater temperature fluctuates by about 10 to 28 ° C. depending on the season, and the heat exchange action changes depending on the season.

[0006] Therefore, in the COG indirect cooling type cooling device, a plurality of units are installed corresponding to the maximum amount of coke production. Therefore, during regular repair of the coke oven or low load operation of the coke production, the COG In many cases, measures were taken to operate only the cooling device of the number corresponding to the generated amount and stop the rest.

Further, the amount of cooling water for heat exchange which is passed through the cooling pipe has been adjusted.

[0008]

However, the method of operating only the cooling device of the radix corresponding to the amount of COG generated in the prior art described above is a method of operating the CO in the cooling device of the limited radix.
Since the radix corresponding to the G generation amount is operated, the capacity of the cooling device is likely to have excess or deficiency with respect to the COG generation amount, and work such as switching the COG flow path and cooling water of the operating / stopping cooling device is performed. Was complicated.

Further, with respect to the change in the temperature of the cooling water, the amount of water may be adjusted in consideration of the cooling action, but strict control has not been performed.

On the other hand, in the method of adjusting only the amount of cooling water according to the amount of COG generated, the capacity of the indirect cooling type cooling device (hereinafter, also simply referred to as indirect cooling device) during low load operation of the coke oven. Therefore, even if the amount of cooling water is adjusted to the required amount, the temperature of the cooling water after heat exchange (that is, the cooling water outlet temperature of the indirect cooling device) becomes too high, or the COG cooling temperature (that is, the cooling water outlet temperature). The COG outlet temperature of the indirect cooling device) was too low.

The reason why the cooling operation cannot be properly performed by the means for adjusting only the amount of cooling water during the low load operation of the coke oven is that the cooling capacity (the number and length of cooling pipes) of the indirect cooling device is excessive. This is because it is fixed.

When the cooling temperature of COG in the indirect cooling device becomes too low and becomes lower than 50 ° C., naphthalene is deposited and adheres to the outer surface of the cooling pipe to narrow the flow passage, resulting in an increase in pressure loss. come. Further, if the outlet temperature of seawater used for cooling water becomes too high and exceeds 70 ° C, the cooling pipe is likely to be damaged by high-temperature corrosion of seawater due to the formation of highly corrosive CaCO ₃ .

Therefore, when the amount of naphthalene attached to the cooling pipe increases, a cleaning operation for removing it becomes necessary,
There is a problem that the life of the cooling pipe is shortened due to high temperature corrosion.

Therefore, an object of the present invention is to solve the above problems and to change the COG generation amount and the cooling water temperature without adjusting the radix of the cooling device (that is, without suspending a part). In response to the change, the COG cooling temperature at which naphthalene is not substantially deposited is adjusted, and the temperature of the cooling water after heat exchange is adjusted so that high-temperature corrosion does not easily occur in the cooling pipe.
The present invention provides a COG cooling method and an indirect cooling device for indirectly cooling seawater by passing seawater as cooling water through a large number of cooling pipes.

[0015]

In order to achieve the above object, the inventor of the present invention is eager to provide a COG cooling method and an indirect cooling device for indirectly cooling COG by passing seawater through a large number of cooling pipes. As a result of the examination, the cooling pipes can be blocked or bypassed by partially blocking the passage for passing the cooling water to the cooling pipes without changing the fixed cooling capacity (number and length of cooling pipes) of the cooling device. By freely adjusting the effective heat exchange area of, naphthalene is less likely to precipitate (preferably,
The present invention has been completed based on the finding that the cooling temperature of COG (which does not precipitate) and the temperature after heat exchange of cooling water that does not easily cause high-temperature corrosion can be set.

That is, the means (1) of the present invention is a COG.
In a COG cooling method in which multiple cooling pipes are used for indirect cooling, the flow rate of cooling water flowing through the cooling pipes is adjusted according to the COG amount and cooling water temperature, and a part of the cooling pipes is shielded to provide a heat exchange area. Is adjusted so that the COG cooling temperature is equal to or higher than a predetermined temperature at which naphthalene is not substantially precipitated, and the cooling water outlet temperature is equal to or lower than a predetermined temperature at which hot corrosion does not easily occur.

In the means (2) of the present invention, as a means for adjusting the heat exchange area of the cooling pipe, a rubber shield plate that can be automatically opened / closed from the outside is provided in a part of the cooling pipe to adjust the COG cooling temperature. The cooling method according to (1) above is characterized in that the heat exchange area of the cooling pipe is adjusted by automatically opening and closing the flow paths of some of the cooling pipes according to the temperature of the cooling water after heat exchange.

The means (3) of the present invention is a COG cooling method for indirectly cooling COG using a plurality of cooling pipes,
A cooling water bypass passage whose flow rate can be adjusted from the outside is provided, and a part of the cooling water is bypassed to the cooling water outlet side according to the COG amount and the cooling water temperature.
The bypass flow rate is adjusted so that the cooling temperature of the COG is equal to or higher than a predetermined temperature at which naphthalene does not substantially precipitate, and the temperature after heat exchange of the cooling water is equal to or lower than a predetermined temperature at which high temperature corrosion does not easily occur. Is the way.

In the means (4) of the present invention, as a means for bypassing, a flow rate control valve capable of automatically operating the opening of the bypass passage from the outside is provided, and after the COG cooling temperature and the cooling water are exchanged with each other. It is also achieved by the cooling method described in the above (3), characterized in that the bypass flow rate is automatically adjusted according to the temperature.

The means (5) of the present invention is a coke oven gas cooling device for indirectly cooling the coke oven gas by passing seawater as cooling water through a large number of cooling pipes to cool the coke oven gas at a naphthalene temperature. Is a predetermined temperature at which substantially no precipitation occurs and a cooling means for adjusting the cooling water outlet temperature to a predetermined temperature at which hot corrosion does not easily occur is provided.

The means (6) of the present invention is, as the adjusting means, according to the coke oven gas amount and the cooling water inlet temperature,
The coke oven gas according to the above (5), further comprising: a unit for adjusting a flow rate of cooling water flowing through the cooling pipe; and a unit for shielding a part of the cooling pipe to adjust a heat exchange area. It is a cooling device.

In the means (7) of the present invention, as a means for adjusting the heat exchange area of the cooling pipe, a part of the cooling pipe is provided with a rubber shielding plate which can be automatically opened and closed from the outside, and the coke oven gas outlet temperature and The coke oven gas cooling device according to (6) above, wherein an automatic opening / closing mechanism for a part of the cooling pipe flow path using the shielding plate is provided depending on the cooling water outlet temperature.

In the means (8) of the present invention, as the adjusting means, means for bypassing a part of the cooling water to the cooling water outlet side is provided depending on the outlet of the coke oven gas and the cooling water outlet temperature. The coke oven gas cooling device according to (5) above.

The means (9) of the present invention comprises, as the bypass means, a bypass flow passage for bypassing a part of the cooling water to the cooling water outlet side, and a flow rate at which the opening of the bypass flow passage can be automatically controlled from the outside. The coke oven gas cooling device according to (8) above, further comprising a control valve.

The "heat exchange area" of the present invention means the heat exchange action (of the indirect cooling type cooling device used as a multi-tube heat exchanger used) when indirectly cooling using a large number of cooling pipes. It refers to the external surface area of the cooling pipe that is effectively utilized. In claims 1, 2, 6, and 7 of the present invention, since the cooling water in the shielded cooling pipe remains inside, the temperature gradually becomes the same as the COG temperature of the external fluid and the heat exchange action disappears. However, since it seems that there is a heat transfer effect even at the same temperature, the commonly used "heat transfer area"
May be understood to include the external surface area of the shielded cooling tube which eliminates the heat exchange effect. Therefore, in order to avoid such misunderstandings, the “heat exchange area” is used, and the external surface area of the shielded cooling pipe is clarified not to be included in the “heat exchange area” to distinguish it from the “heat transfer area”. Used for.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of a known general cooling device to which the cooling method of the present invention can be preferably applied. FIG. 2 is an elevation view of the cooling device taken along the line AA of FIG. The cooling device that can be used in the cooling method of the present invention is a multi-tube heat exchanger that indirectly cools COG using a large number of cooling tubes (vertical tubes), and is a known general indirect cooling system cooling. It can be widely applied to those having the same device configuration as the device.

As shown in FIG. 1 and FIG. 2, the COG inlet 101 for introducing COG into the cooling device main body 109 as the fluid outside the cooling pipe 111 by suction of a gas blower (not shown) has a cooling device main body 101. The COG outlet 10 is provided at the upper part of one side surface (left side surface in the drawing) of 109, and is supplied to a subsequent direct cooling type cooling device (not shown, see FIG. 7).
3 is provided on the lower part of one side surface (right side surface in the drawing) of the apparatus main body 109 which faces the apparatus main body 109.

Further, the indirect cooling type cooling device main body 109 has a zigzag COG flow path (up and down) so that the heat exchange efficiency between the COG entering the inside of the device main body 109 and the seawater used as cooling water can be improved. In order to form a U-shaped arrow in the figure), a large number of upper and lower gas side partition plates 115a and 115b are arranged inside the apparatus main body 109. In the gas flow path,
A large number of cooling pipes 111 are arranged, and each of these cooling pipes 111 is
Both ends of are fixed by an upper tube sheet 117 and a lower tube sheet 113. At this time, the openings at both ends of each cooling pipe 111 communicate with upper / lower water chambers 117a, 113 and upper / lower water chambers 106a-d, 108a-c formed by upper / lower water chamber partition plates 121, 119. Has been done. Further, in the lower water chamber 106a on the COG outlet 103 side, CO
A seawater inlet 105 is provided so as to have a countercurrent to the entrance and exit of G. A seawater (cooling water) supply pipe 135 is connected to the seawater inlet 105. A seawater outlet 107 is provided in the upper water chamber 3 chamber 108c on the COG inlet 101 side.
At the seawater outlet 107, cooling water is circulated in the cooling pipe 111 of the apparatus main body 109 to cool COG by the direct cooling type cooling device, and then to be supplied to the indirect cooling device.
Are connected. In FIG. 1, the lower water chamber located at the bottom of the device body 109 is divided into four lower water chambers from one lower water chamber partitioned by three lower water chamber partition plates 119 for convenience of explanation. , The seawater inlet 105, which is cooling water, is located in the rightmost lower water chamber 106a, and the seawater outlet 107 is located in the leftmost lower water chamber 4a.
It is supposed to be provided in 106d. Similarly, the device body 1
For convenience of explanation, the upper water chamber located at the upper part of 09 is divided into three upper water chambers from one upper water chamber partitioned by two upper water chamber partition plates 121. As a result, the seawater inlet 10
Seawater entering from 5 flows from the lower water chamber 1 chamber 106a to the cooling pipe 111.
Through to the upper water chamber 1 chamber 108a, and thereafter, the upper water chamber 1 chamber 108a → cooling pipe 111 → lower water chamber 2 chamber 106b → cooling pipe 111
→ Upper water chamber 2 chamber 108b → Cooling pipe 111 → Lower water chamber 3 chamber 106c
→ Cooling pipe 111 → Upper water chamber 3 chambers 108c → Cooling pipe 111 → Lower water chamber 4 chambers 106d → Seawater outlet 107 and is discharged. The above is an outline of a multi-tube heat exchange type cooling device including a large number of general vertical tubes (cooling tubes). 1 and 2, the number of cooling pipes and water chambers is shown in a very simplified manner for convenience of explanation, and in reality, there are several thousand cooling pipes depending on the COG emission amount. Is used, and one with more water chambers is used.

In the cooling method using the cooling device having the above structure shown in FIGS. 1 and 2, a gas blower (not shown) is used.
Of high temperature C discharged from the dry main (not shown) of the coke oven to the cooling device main body 101 which has been placed in a negative pressure state by suction of
By introducing OG and performing a heat exchange action with the cooling pipe 111 through which low temperature seawater flows, the OG is cooled to a desired temperature and then supplied to a subsequent direct cooling type cooling device.

In the cooling method of the present invention, the COG amount, cooling water temperature,
The present invention provides a specific means for keeping the cooling temperature of COG and the outlet temperature of cooling water within a certain range by using the heat exchange area of the cooling pipe or the bypass flow rate as a parameter.

As a first embodiment of the COG cooling method of the present invention, in the COG cooling method in which the COG is indirectly cooled by passing seawater as cooling water through a large number of cooling pipes, C
The cooling water flow rate flowing through the cooling pipe is adjusted according to the OG amount and the cooling water temperature, the heat exchange area is adjusted by shielding a part of the cooling pipe, and the COG cooling temperature is equal to or higher than a predetermined temperature at which naphthalene does not substantially precipitate. In addition, the temperature of the cooling water after heat exchange is set to a predetermined temperature or less at which high temperature corrosion is less likely to occur.

As a cooling device that can be used in the above COG cooling method, a COG cooling device for indirectly cooling COG by passing seawater as cooling water through a large number of cooling pipes is used. Is provided above a predetermined temperature at which naphthalene is not substantially precipitated, and a cooling water outlet temperature is provided below a predetermined temperature at which high temperature corrosion is unlikely to occur. Further, as the adjusting means, the COG amount and the cooling water inlet temperature are provided. Accordingly, it is characterized by comprising means for adjusting the flow rate of the cooling water flowing through the cooling pipe, and means for adjusting the heat exchange area by shielding a part of the cooling pipe.

In the first embodiment of the COG cooling method of the present invention, both the flow rate of the cooling water flowing through the cooling pipe and the heat exchange area are adjusted according to the COG amount and the cooling water temperature.

First, the saturation enthalpy of COG is calculated from the COG amount / temperature (COG inlet temperature and outlet temperature), pressure, saturated vapor pressure, etc. in the indirect cooling device used in the present invention, and the cooling water temperature (cooling water temperature) is calculated. Calculate the required cooling water flow rate from the temperature difference between the temperature before exchange and the temperature after heat exchange. One specific calculation example is shown below, but the invention is not limited to these. These are normally entered by inputting numerical values such as COG amount / temperature, pressure, saturated vapor pressure, cooling water temperature, etc. into the computer in which the heat transfer calculation formula is programmed.
The required cooling water flow rate can be determined. These may be automatically calculated based on data from a detection unit such as a flow meter or a thermometer included in the cooling device. Further, the control device may calculate the required cooling water flow rate based on the data from these detection sections, and the opening degree of the cooling water flow rate adjusting valve (operation section) may be adjusted based on the calculation result. That is, the calculation of the cooling water flow rate by the heat transfer calculation formula is
Saturation of COG from the COG inlet temperature and outlet temperature, pressure, saturated vapor pressure, etc. determined by the capacity of the COG purification system and cooling device to be applied according to the parameters COG amount and cooling water temperature (inlet temperature) The enthalpy and even the required cooling water flow rate can be determined.

For example, under the following COG and cooling water (seawater) conditions, the relationship among the cooling water flow rate, the heat transfer area, and the cooling water outlet temperature is obtained.

COG condition Cooling water condition-Flow rate 30,000 Nm ³ / h-Inlet temperature 10 ° C-Inlet temperature 82 ° C-Outlet temperature (70 ° C or less) -Inlet side pressure-1.35 kPa-Outlet side pressure-1.85 kPa Overall heat transfer coefficient U = 200kcal / m ² / h ・ ° C (1) COG calorie calculation on cooling device inlet side Saturated moisture (Dry) per kg COG (18 / 10.9) × 51.3 / (101.29 + (-1.35) -51.3) = 1.7415 kg / kg In the above, 18: molecular weight of water (−) 10.9: molecular weight of COG (−) 101.29: atmospheric pressure (Kpa) 51.3: COG vapor pressure (Kpa) saturated COG enthalpy 0.68 × 82 + 0.000215 × 82 ² + 1.7415 × (597.1 + 0.45 × 82) = 1,
161 kcal / kg In the above, 0.45: specific heat of water (kcal / kg) 597.1: latent heat of water (0.45 × 82): sensible heat of water in COG (0.68 × 82 + 0.000215 × 82 ² ). : COG (Dry) 1kg
Heat quantity per unit COG Inlet side heat quantity Q ₁ Q ₁ = 30,000 × (10.9 / 22.4) × 1.161 = 16,953,595 kcal / h In the above, 22.4: COG 10.9 kg (1 kg mol)
Volume occupied by (m ³ ) (2) COG calorie calculation on the cooling device outlet side Saturated moisture (Dry) per kg COG (18 / 10.9) × 15.7 / (101.29 + (-1.85) -15.7) = 0.30913kg / kg saturated COG Enthalpy 0.68 × 55 + 0.000215 × 55 ² + 0.30913 × (597.1 + 0.45 × 55) = 2
30.28kcal / kg COG outlet side heat quantity Q ₂ Q ₂ = 30,000 × (10.9 / 22.4) × 230.28 = 3,361,733kcal / h (3) Cooling water (seawater) removal heat quantity Q ₃ is Q ₃ = 30,000 × (10.9 / 22.4) × (1161.35-230.284) = 13,59
1,862kcal / h (4) Where, the outlet temperature of the cooling water is 65.9 ° C (<70
℃), cooling water flow rate = Q ₃ /(65.9-10)×(1/1000)=243m ³ / h The required heat transfer area A is U = 13,591,862 // (28.12 × A) = 200kcal / m ² · h · ° C where 28.12: logarithmic mean temperature difference Δt Δt ₁ : COG inlet side temperature (82 ° C) -cooling water outlet side temperature 65.9
℃ = 16.1 ℃ Δt ₂ : COG outlet side temperature (55 ℃) -Cooling water inlet side temperature 10 ℃
= 45 ° C Δt = (16.4-45) / (ln (16.1 / 45)) = 28.12 ° C, A = 2,420 m ² .

As a means for adjusting the flow rate of the cooling water, for example, as shown in FIG. 1, a gas flow meter (disposed on the discharge side of the gas blower so that the COG amount and the cooling water temperature can be measured ( A detection unit (not shown) is installed in the seawater inlet 105 or a seawater inlet thermometer (detection unit, not shown) near the seawater inlet 105 of the seawater supply pipe connected to the seawater inlet 105 (further , If necessary,
The necessary detectors such as thermometers, pressure gauges, and gas flow meters may be installed in appropriate places in the equipment). Further, a calculation process is performed based on the measurement data such as the COG amount and the cooling water temperature measured by the detection unit such as the flow meter and the thermometer, and the opening degree adjustment is performed on the flow rate adjusting valve (operating unit) based on the calculation result. Provide a control device (computer) for issuing instructions. Further, a flow rate adjusting valve (operating unit) 133 for adjusting the cooling water flow rate based on the calculation result by the control device is installed on the path near the seawater inlet 105 of the seawater supply pipe 135 connected near the seawater inlet 105. Has been done. Then, the detection unit, the operation unit, and the control device are electrically connected. As a result, the COG is controlled by the control device based on the measurement data of each detector.
The saturation enthalpy is calculated, the required cooling water flow rate is calculated from the cooling temperature (outlet / inlet temperature difference) of the cooling water, and the flow rate is the operation unit that can supply the required cooling water flow rate based on the calculation result. By issuing an instruction to adjust the opening of the valve 133, the flow rate of the cooling water flowing through the cooling pipe may be automatically adjusted according to the COG amount and the cooling water temperature.
However, the present invention does not exclude a method of manually adjusting the flow rate of the cooling water flowing through the cooling pipe according to the COG amount and the cooling water temperature.

Next, the indirect cooling device is operated at the obtained cooling water flow rate, and the cooling temperature of the COG is equal to or higher than a predetermined temperature at which naphthalene is not substantially deposited, and the outlet temperature of the cooling water is equal to or lower than a predetermined temperature at which high temperature corrosion is unlikely to occur. Thus, the heat exchange area of the cooling pipe may be adjusted. Specifically, the heat exchange area of the cooling pipe may be reduced by shielding a part of the cooling pipe. As a result, even during low load operation of the coke oven, as in normal load operation, it is possible to operate the entire cooling system without the precipitation of naphthalene and the problem of high temperature corrosion. .

The means for adjusting the heat exchange area of the cooling pipe is not particularly limited, but it is preferable to partially block the passage of the cooling pipe to invalidate the heat exchange action. . A specific means for adjusting the heat exchange area of the cooling pipe will be described with reference to FIGS. 1 and 2 described above.

1 and 2, a preferred embodiment of a means (shielding means for the cooling pipe) for adjusting the heat exchange area by shielding a part of the cooling pipe is shown in FIG. A rubber sheet that can be opened and closed automatically is provided, and a so-called rubber sheet that is provided with an automatic opening and closing mechanism for some cooling pipe channels using the shielding plate depending on the coke oven gas outlet temperature and the cooling water outlet temperature The state which provides the opening / closing mechanism of a shielding board is shown typically. In addition, FIGS. 1 and 2 are shown in FIGS.
FIG. 4 is a detailed view of the shielding part in the opening / closing mechanism of the rubber sheet shielding plate, showing how the curved rubber sheet closes the inlet and adjusts the number of cooling tubes at the end lifting height of the rubber sheet shielding plate. Show.

As shown in FIGS. 1 and 2, as a mechanism for opening and closing the rubber sheet shielding plate, first, one end of a cooling pipe opening of a part of the upper water chamber 108 is fixed to the upper tube plate by a rubber sheet fixing metal fitting 127. A sheet (shielding plate) 123 is arranged. Further, a pulley 12 driven by a servo motor (not shown)
Rubber sheet lifting device 12 with rope 126 wound around 4
5 is installed in the cooling device, and the end of the rope 126 is connected to the other end of the rubber sheet 123. More specifically, a rubber sheet lifting device 125 (specifically, a pulley 124 driven by a servo motor) set outside the cooling device body 109 (for example, as shown in FIG. 1 above the ceiling wall of the cooling device body 109). The rope 126) that has passed through the wall (ceiling wall) of the cooling device body 109 is connected so that the other end of the rubber sheet 123 can be pulled. Then, if the rope 126 is loosened, the cooling pipe 111 is closed, and if pulled, it is opened. Explaining with reference to FIG. 3 and FIG. 4, the number of the cooling pipes 111 that block the inflow port by the curved rubber sheet 123 can be adjusted by the lifting height of the end of the rubber sheet 123. .

5 (a) and 5 (b) show a state in which the rope 126 is loosened and the cooling pipe 111 is closed. The end of the rubber sheet 123 is lowered to the bottom so that the rubber sheet 123 can be closed. 3 shows a state in which all the cooling pipes 111 are closed (the entire rubber sheet is in close contact with the upper tube sheet). On the other hand, in FIGS. 6A and 6B, the rope 126 is pulled to pull up the end of the rubber sheet 123 and the curved rubber sheet 123 blocks 50% of the cooling pipe 111 inflow port that can be closed. It is shown. It should be noted that when the other end of the rubber sheet 123 is pulled up to the highest position, the cooling inlet of the cooling pipe 111 is not blocked by the rubber sheet 123 and all the cooling pipes 111 are closed.
Is capable of effectively exhibiting a heat exchange effect (it can be said that the coke oven is operating under normal load or when seawater is warm).

The servo motor of the rubber sheet elevating / lowering device 125 is operated to receive a signal from a temperature measuring device for detecting the COG outlet temperature and the cooling water outlet temperature and automatically adjust the required area of the cooling pipe. For example, when the cooling water outlet temperature exceeds 70 ° C, the rubber sheet lifting device operates the servo motor to lower the rubber sheet, and cools until the cooling water temperature is 70 ° C or lower and the COG cooling temperature is 50 ° C or higher. The seawater entering the pipe should be blocked. Alternatively, based on the temperature data from the temperature measuring device for detecting the COG outlet temperature and the cooling water outlet temperature, the number of blockages of the cooling pipe 111 by the rubber sheet (the heat exchange area to be invalidated) is calculated by the computer (control device). , The pulley needed for that
The amount of vertical fluctuation of the rope 126 wound around 124 and the amount of rotation of the servo motor necessary for the amount of vertical fluctuation are calculated, and the servo motor is operated based on the calculation result, and when the cooling water temperature is 70 ° C. or less, COG The cooling temperature may be adjusted to 50 ° C. or higher.

The temperature measuring device for detecting the COG outlet temperature and the cooling water outlet temperature measures the COG outlet temperature (COG cooling temperature) in the vicinity of the COG outlet of the COG discharge pipe connected to the COG outlet, for example. For this purpose, a COG outlet thermometer 129 may be provided, and a seawater outlet thermometer 131 for measuring the seawater outlet temperature may be provided near the seawater outlet of the seawater outlet pipe connected to the seawater outlet. A conventionally known thermometer or temperature sensor can be used as the temperature measuring device.

As means for automatically opening and closing the shield plate from the outside, as shown in FIG. 1, in addition to a rubber sheet lifting device provided with a rope 126 wound around a servo motor driven pulley 124, a servo is used. An elevating device provided with a servo mechanism, such as a rubber sheet elevating device provided with a rope fixed to a cylinder-driven piston, can be used, but it is not particularly limited.

The cooling pipe 111 inflow port of the upper water chamber 108 means the upper opening of the cooling pipe 111 for passing seawater from the upper water chamber 1 chamber 108a to the lower water chamber 2 chamber 106b, and the upper water chamber. The upper opening of the cooling pipe 111 for passing seawater from the second chamber 108b to the third lower chamber 106c.

In the present invention, not only the above-mentioned rubber sheet, but also any usable shielding plate, the overall size thereof depends on the capability of the coke oven and the COG refining system to which it is applied, when the coke oven operates at the lowest load. At
Further, it is sufficient if the number of cooling pipes corresponding to the heat exchange area to be shielded can be closed in the state where the cooling water (seawater) temperature is the lowest. For example, calculate the heat exchange area that should be shielded when the coke oven is regularly repaired or when the coke production is low and the cooling water (seawater) temperature is the lowest during the lowest load operation. The size of the rubber sheet may be set according to the above, or the rubber sheet may be attached to the rubber sheet fixing bracket 127 and the rubber sheet lifting device 1
25, which can be detachably connected and may be replaced with a rubber sheet of a size that corresponds to the heat exchange area to be shielded that is required during low-load operation or in each season. is not. Preferably, the former is preferable because the replacement work is unnecessary and the function of the rubber sheet lifting device 125 can be effectively used.

Further, as shown in FIGS. 1 and 2, not only the rubber sheet 123 but also any shielding plate that can be used,
It is not necessary to provide one shielding plate for each upper water chamber, and a plurality of them may be installed and used. For example, shield plate (rubber sheet 12
3) are provided on both sides of the device, and the other ends of these shielding plates (rubber sheets 123) are tied together by a suitable connecting bar, and the connecting bars are connected to the rope of the shielding plate (rubber sheet) lifting device 125. May be. By doing so, the left and right shield plates can be moved up and down symmetrically in conjunction with the raising and lowering of the rope 126 of the single shield plate lifting device 125. It should be noted that the present invention is not particularly limited to these, and for example, by connecting a plurality of shield plates to different shield plate elevating devices, vertical movement of the shield plate elevating device corresponding to each shield plate can be achieved. It can also be adjusted in response. Further, instead of arranging the shielding plates on both side surfaces, they may be arranged in the central portion or may be arranged in a larger number (three or more). In FIG. 1, the number of heat transfer tubes to be closed by the rubber sheet is set to several for convenience of explanation, but it may be necessary to close a larger number (for example, several hundreds) in practice.

In the above embodiment, rubber was used as the material of the shielding plate that closes the cooling pipe. However, the present invention is not limited to these materials. For example, other than rubber (including elastomer), Metals (including alloys), ceramics, plastics (plastics), wood, composite materials such as fiber reinforced glass, and composite materials and laminated materials of these, which have the effect of blocking the flow of cooling water to the cooling pipe. Any material can be used as long as it is a material. Preferably, the adhesiveness to the upper tube sheet is excellent, the sealing effect at the time of shielding is large, the flexibility, flexibility, and rubber-like elasticity are excellent, and the bending (deflection) effect as shown in FIG. 4 is obtained. It is preferable to use rubber (including an elastomer and a rubber-based composite material) because the shielding area can be adjusted arbitrarily. Examples of the elastomer include polyurethane and polyester containing block units such as polyether and polyester. A rubber-based composite material is a material in which rubber, which is rich in elasticity, is reinforced with a reinforcing material to give strength, wear resistance, and impact resistance, and examples thereof include aramid, nylon, carbon,
Carbon black, steel, etc. reinforced with fibers and particles, etc., such as ABS (acrylonitrile butadiene styrene) resin and high impact styrene (HIP
S) resin is also included.

The position of the shield plate is open at the top because it is difficult to deal with the occurrence of equipment troubles, so that it is easy to take emergency measures, and the periodic inspection and cleaning work are easy. From the point, it is installed on the upper water chamber side, and as shown in FIG. 1, a part of the cooling pipe inlet used for passing cooling water from the upper water chamber side to the lower water chamber side is shielded. Install.

The fixing member for fixing one end of the shielding plate, which is one of the means for automatically opening and closing the shielding plate such as a rubber sheet, is not particularly limited and is conventionally known. Various fixing members can be used. It is desirable that the shield plate can be detachably fixed. In addition, in response to long-term fluctuations in seawater temperature,
A plurality of fixing members may be provided so that the shielding plate can be replaced with a shielding plate having a different size depending on the season, and can be appropriately used depending on the size of the shielding plate.

Further, as shown in FIGS. 1 and 2, an embodiment in which a rubber sheet shielding plate opening / closing mechanism is provided in the upper water chamber 1 chamber 108a and the upper water chamber 2 chamber 108b represents a COG. Similarly, for the three upper water chambers on the inlet side, a rubber sheet, a rubber sheet lifting device, and a rubber sheet fixing bracket are used to adjust the heat exchange area of the cooling pipe in the same manner as the above-described upper water chamber 1 chamber 106a. An opening / closing mechanism for the rubber sheet shielding plate may be provided for this purpose. However, in the three upper water chambers on the COG inlet side, close to the COG inlet 101, and if a part of the cooling pipe 111 is closed here, the seawater in the closed cooling pipe 111 will not be replaced and the high temperature (about 80 ° C.) Due to heat exchange with COG, it may be heated to a temperature at which high temperature corrosion is likely to occur. Therefore, it can be said that in the upper water chamber on the COG inlet side, it is desirable not to adjust the heat exchange area of the cooling pipe using the rubber sheet, the rubber sheet lifting device, and the rubber sheet fixing fitting. This is because in an indirect cooling type cooling device, a plurality of upper water chambers are usually formed, but in one of these water chambers, the heat exchange area of the cooling pipe using the opening / closing mechanism of the rubber sheet shielding plate This is because the action and effect of the present invention can be sufficiently achieved without adjustment.

In the present invention, according to the COG amount and the cooling water temperature measured by the gas flow meter provided in the COG supply pipe and the seawater inlet thermometer provided in the seawater supply pipe, for example, the COG amount as described above. -Calculate the required cooling water flow rate by inputting values such as temperature, pressure, saturated vapor pressure, cooling water temperature, etc. into the computer in which the heat transfer calculation formula is programmed. That is, according to the heat transfer calculation formula, the cooling temperature of the COG (the temperature measured by the COG outlet thermometer 129 provided in the vicinity of the COG outlet in FIG. 2) is equal to or higher than a predetermined temperature at which naphthalene does not substantially precipitate (specifically, 50 ° C. or higher). The temperature of the cooling water outlet (in FIG. 2, the temperature measured by the seawater outlet thermometer 131 provided in the vicinity of the seawater outlet) was set to 55 ° C. in the heat transfer calculation formula of Example 1 described later). Less than a predetermined temperature that is unlikely to occur (specifically, 70 ° C. or less, Example 1 described later)
The heat transfer calculation formula was 65.9 ° C. ),
It is actually necessary to calculate and adjust the flow rate of the cooling water flowing in the cooling pipe 111, and to shield a part of the cooling pipe 111 from the excessive heat exchange area by using the above-mentioned opening / closing mechanism of the rubber sheet shielding plate. Adjust so that the heat exchange area is obtained.

Here, the COG cooling temperature (COG outlet temperature of the indirect cooling device) may be a predetermined temperature or higher at which naphthalene does not precipitate, and is specifically 50 ° C. or higher, preferably 53 ° C. or higher, and more preferably. It is 55 ° C or higher. In the vicinity of 50 ° C, about 10 g of naphthalene is contained in the COG discharged from the dry main of the coke oven as described above.
Since Nm ^{3 is} contained, a slight amount of naphthalene may be precipitated (see FIG. 8), but the amount of naphthalene in COG cannot always be said to be 10 g / Nm ³ . Depending on the type of coal and the operating conditions of the coke oven, the amount of naphthalene in COG may be 8 to 9 g / Nm ³ , in which case naphthalene may not precipitate even at 50 ° C. Even if it precipitates, the amount is extremely small, so the cleaning cycle of the cooling device can be extended, so there is no particular problem in actual operation.In such cases, it is included in the "predetermined temperature at which naphthalene does not precipitate". Shall be provided. On the other hand, 50
When the temperature is lower than 0 ° C, as shown in Fig. 8, the amount of naphthalene deposited on the outer surface of the cooling pipe rapidly increases due to the temperature decrease, and the heat exchange area decreases, so that periodic cleaning is required.

The temperature of the cooling water outlet (the temperature of the cooling water outlet of the indirect cooling type cooling device) may be a predetermined temperature or less at which high temperature corrosion does not easily occur, and is 70 ° C. or less.

The lower limit value of the cooling water outlet temperature is not particularly limited because it depends on the temperature of the seawater used for the cooling water and the cooling water flow rate (flow velocity).

As a method for adjusting the heat exchange area of the cooling pipe, a rubber shield plate that can be automatically opened and closed from the outside is provided in a part of the cooling pipe, and the cooling temperature of the coke oven gas and the cooling water are set. There is a method of adjusting the heat exchange area of the cooling pipe by automatically opening and closing the flow paths of some cooling pipes depending on the temperature after the heat exchange. Specifically, the device is operated in accordance with the cooling water flow rate obtained by the above calculation formula so that the COG cooling temperature and the temperature after heat exchange of the cooling water fall within the range specified above.
It may be adjusted by shielding the excessive heat exchange area by using the opening / closing mechanism of the rubber sheet shielding plate described above. Particularly, by adjusting the amount of heat exchange area according to the cooling temperature of COG during operation and the temperature after heat exchange of cooling water, it is possible to constantly prevent precipitation of naphthalene and high temperature corrosion during operation. Is advantageous.

Further, the method for automatically opening / closing the flow paths of some cooling pipes to adjust the heat exchange area of the cooling pipes depending on the cooling temperature of the coke oven gas and the temperature after the heat exchange of the cooling water is particularly limited. This is not what is to be done, and a conventionally known automatic opening / closing control technique for an opening can be applied. Specifically, as described above, one end of a rubber sheet that is a shielding material is fixed to a predetermined position of the upper tube sheet by an appropriate fixing member, and the other end is a rope for a lifting device including a servo mechanism. Connect to. Further, a temperature measuring unit that measures the COG outlet temperature and the cooling water outlet temperature and the driving unit of the lifting device that is the operating unit are electrically connected to the control device. And the control device
At 139, arithmetic processing is performed based on the data such as the COG outlet temperature and the cooling water outlet temperature from the measuring unit to obtain the number of cooling pipes required for shielding, and further the amount of fluctuation of the rope of the lifting device (vertical movement width). ) Is calculated, and the operation amount of the drive unit is calculated. Based on the calculation result, the driving unit of the lifting device, which is the operating unit, is operated to automatically adjust the vertical movement width, and the other end of the shield plate connected to this is vertically moved to shield the target number of cooling pipes. can do. During the operation of the cooling device, it is desirable to automatically open and close the flow path of the cooling pipe to adjust the heat exchange area of the cooling pipe so that the COG outlet temperature and the cooling water outlet temperature are always at the predetermined temperatures.

For example, as shown in FIGS. 5 (a) and 5 (b), from the calculation result, when it is necessary to shield the flow path of the cooling pipe by using the entire surface of the installed shielding plate (that is, the shielding rate of 100). %), The fluctuation amount of the rope of the lifting device (vertical movement width) is obtained as the maximum downward movement width. By operating the drive unit of the lifting device, which is the operating unit, from the calculation result, the lowering width is automatically adjusted, and the other end of the shield plate connected to this is lowered until it reaches the upper tube plate, and the entire shield plate is reached. Can be brought into close contact with the upper tube sheet. This makes it possible to automatically close all of the flow paths of the cooling pipe that can be shielded by the shielding plate and adjust the heat exchange area of the cooling pipe.

Further, as shown in FIGS. 6 (a) and 6 (b),
From the calculation result, when it is necessary to shield the flow path of the cooling pipe by using the area of approximately half of the installed shielding plate (that is, when the shielding rate is 50%), the fluctuation amount of the rope of the lifting device ( The vertical movement width) is obtained as approximately half of the maximum amount of decrease (actually, the optimum fluctuation amount (vertical movement width) is calculated in consideration of the bending rate of the rubber sheet used for the shielding plate). By operating the drive unit of the lifting device, which is the operating unit, from the calculation result, the vertical movement width is automatically adjusted, so that the other end of the shield plate connected to this is separated from the upper tube sheet by approximately half of the shield plate. It will be in the state of being. Thereby, 50% of the flow path of the cooling pipe that can be shielded by the shielding plate is automatically closed (in other words, 50% is automatically opened), and the heat exchange area of the cooling pipe can be adjusted.

Note that manual operation may be performed instead of the automatic operation shown in FIG.

Next, as a second embodiment of the COG cooling method of the present invention, in a COG cooling method in which COG is indirectly cooled using a large number of cooling pipes, the COG amount and the cooling water temperature are changed according to the COG amount and the cooling water temperature. Bypassing a part of the cooling water to the cooling water outlet side, preferably further adjusting the bypass flow rate, the cooling temperature of the coke oven gas is a predetermined temperature or higher at which naphthalene does not precipitate, and the temperature after heat exchange of the cooling water. Is set to a predetermined temperature or less at which high temperature corrosion does not easily occur.

In the second embodiment, the cooling device is operated at a constant cooling water flow rate (that is, the cooling water flow rate required for cooling the COG amount under normal load in the coke oven), and the COG outlet temperature (cooling After) is the naphthalene precipitation limit temperature of 50 ℃
As described above, part of the cooling water in the cooling device is bypassed from the inlet side to the cooling water outlet side so that the outlet temperature of the cooling water becomes equal to or lower than the temperature (70 ° C.) at which high temperature corrosion is unlikely to occur.

As means for bypassing a part of the cooling water from the inlet side to the cooling water outlet side, a bypass passage is provided in the cooling water passage in the cooling device, and the opening degree of the bypass passage is automatically controlled from the outside. A possible flow rate control valve is provided, the cooling device is operated at the obtained cooling water flow rate, the COG cooling temperature and the temperature of the cooling water after heat exchange are measured, and in the control device,
From the difference between the measured data and the target setting data (for example, COG cooling temperature = 50 ° C. or higher, temperature after cooling water heat exchange = 70 ° C. or lower), the amount of cooling water flowing in the bypass flow passage is calculated, and the bypass flow passage Opening (= opening of flow control valve)
Is calculated, and the amount of rotation of the motor for driving the flow rate control valve required for that is calculated. Based on the calculation result, the start / stop of the operation of the drive motor of the flow rate control valve, which is the operation unit, and the rotation amount during the operation are instructed. The drive motor of the flow rate control valve is operated in accordance with such an instruction to adjust the opening degree of the flow rate control valve (= opening degree of the bypass flow path) to automatically adjust the bypass flow rate.

By the above adjustment, it is possible to reduce the flow rate of the cooling water flowing through the cooling pipe to reduce the amount of heat exchange when the coke oven is operated under a low load. As a result, the COG in the cooling device is reduced even when the cooling capacity (number and length of cooling pipes) of the cooling device is excessive and fixed during low load operation.
Outlet temperature is too low and naphthalene precipitation limit temperature is 5
It is possible to prevent the temperature from dropping below 0 ° C., and prevent naphthalene from depositing and adhering to the outer surface of the cooling pipe to narrow the flow path and increase the pressure loss. On the other hand, the flow rate of the cooling water flowing through the bypass flow passage during the low load operation of the coke oven was increased, and the cooling water at the inlet side (cold water that had not progressed heat exchange) was warmed at the cooling water outlet side (heated by heat exchange). It is possible to lower the cooling water outlet temperature by mixing an appropriate amount with water). As a result, despite the fact that the cooling capacity (number and length of cooling pipes) of the cooling device is excessive and fixed during low-load operation,
It is possible to suppress the temperature rise of the cooling water to a temperature (70 ° C.) or less at which high temperature corrosion is unlikely to occur, and prevent the life of the cooling pipe from being shortened due to high temperature corrosion.

For example, as shown in FIGS. 3 and 4, as a concrete embodiment of the means for bypassing a part of the cooling water to the cooling water outlet side in accordance with the coke oven gas amount and the cooling water inlet temperature, A bypass flow passage for bypassing a part of the cooling water to the cooling water outlet side, and a flow rate control valve capable of automatically operating the opening degree of the bypass flow passage from the outside by the temperature of the coke oven gas outlet and the cooling water outlet are provided. The state of being formed is shown schematically.

As shown in FIGS. 5 and 6, a seawater bypass port 145 is formed in a part of the upper water chamber partition plate 121.
Thereby, a bypass flow path for bypassing a part of the cooling water in one upper water chamber to the upper water chamber adjacent to the cooling water outlet side is formed. Also, a servo motor (not shown)
A plate valve elevating device 143 including a rope 144 wound around a driving pulley 142, and an end of the rope 126 is connected to an upper end of a plate valve 141 is installed in a cooling device. More specifically, a servo motor driven pulley 142 set outside the cooling device main body (for example, as shown in FIG. 4 above the device wall above each upper water chamber partition plate 121 of the cooling device main body 109).
The rope 144 wound around is passed through the wall (ceiling wall) of the cooling device main body 109, and is connected so that the upper end of the plate valve 141 can be pulled. Further, the plate valve 141 is used for the rope 1
It is upright in contact with the upper water chamber partition plate 121 so that the seawater bypass port 145 is closed by loosening it and opened by pulling it, and a rope 144 is connected to the upper end thereof. And rope 144
When the seawater bypass port 145 is closed and the seawater bypass port 145 is closed, the lower end of the plate valve 141 is grounded to the upper tube sheet 117, and the seawater bypass port is entirely closed. Then, the opening height of the seawater bypass port 145 can be adjusted by the lifting height of the plate valve 141. As a result, as described above, even during low load operation, the flow rate of the cooling water flowing through the bypass passage is increased (adjusted) and the flow rate of the cooling water flowing through the cooling pipe is decreased (adjusted) to reduce the heat exchange amount. The cooling temperature of COG can be adjusted to a predetermined temperature or higher at which naphthalene does not substantially precipitate, and at the same time, cooling water at the inlet side can be mixed with the cooling water outlet side to lower the cooling water outlet temperature. The outlet temperature can be adjusted to be equal to or lower than a predetermined temperature at which high temperature corrosion does not easily occur.

The servomotor of the plate valve lifting device 143 receives a signal from a temperature measuring device for detecting the COG outlet temperature and the cooling water outlet temperature. For example, when the cooling water outlet temperature rises, the plate valve opens, As shown in FIG. 3 and FIG. 4, the cooling water flow rate to the upper 1 water chamber rear stage and the upper 2 water chamber front stage / rear stage is reduced (bypass flow rate is increased),
Cooling water outlet temperature below 70 ° C, COG cooling temperature 5
Operated to regulate above 0 ° C. Or COG
Based on the temperature data from the temperature measuring device for detecting the outlet temperature and the cooling water outlet temperature, the computer (control device) calculates the opening degree of the seawater bypass port 145 by the plate valve,
For that purpose, the vertical fluctuation amount of the rope 126 wound around the pulley 124 and the rotation amount of the servo motor necessary for the vertical fluctuation amount are calculated, and based on the calculation result, the servo motor is operated so that the cooling water temperature is 70%. You may adjust so that the cooling temperature of COG will be 50 degreeC or more at below (degreeC).

The temperature measuring device for detecting the COG outlet temperature and the cooling water outlet temperature measures the COG outlet temperature (COG cooling temperature) in the vicinity of the COG outlet of the COG discharge pipe connected to the COG outlet, for example. For this purpose, a COG outlet thermometer 129 may be provided, and a seawater outlet thermometer 131 for measuring the seawater outlet temperature may be provided near the seawater outlet of the seawater outlet pipe connected to the seawater outlet. A conventionally known thermometer or temperature sensor can be used as the temperature measuring device.

As means for automatically operating the opening of the bypass passage from the outside by using the flow rate control valve, the pulley 124 driven by the servo motor in the first embodiment is used.
Plate valve lifting device 143 with rope 126 wound around
In addition to the above, an elevating device including a servo mechanism such as a plate valve elevating device including a rope fixed to a piston driven by a servo cylinder can be used, but it is not particularly limited. It is desirable to install the lifting / lowering device main body provided with such a servo mechanism outside the cooling device main body because it does not obstruct the flow of the cooling water, but in the present invention, it is installed inside the cooling device main body. It does not exclude form.

Also in the second embodiment of the present invention, FIG.
The present invention is not limited to the specific embodiment described in 4 and 4, and may be any one as long as the effects of the present invention can be obtained.

The position, size and number of such suitable seawater bypass ports formed on the partition plate of the upper water chamber are not particularly limited, and the capacity (COG amount) of the coke oven to which the present invention is applied is not limited. Since the capacity of the cooling device also varies depending on the amount of change in seawater temperature, etc., the optimum formation position and size may be appropriately selected according to the capacity of the cooling device to which the present invention is applied.

Further, which of the plurality of upper water chamber partition plates is formed with the seawater bypass port is particularly limited as long as the COG cooling temperature and the cooling water outlet temperature can be adjusted within a predetermined temperature range. It should be.

The method for adjusting the flow rate of the bypass passage of the cooling water is not particularly limited as it depends on the bypass passage forming means described above.
Conventionally known flow rate adjusting means can be appropriately used.
Specifically, for example, when a seawater bypass port is formed in a part of the upper water chamber partition plate as the bypass flow passage forming means, a plate valve lifting device as shown in FIGS. 5 and 6 can be provided. Besides, the plate valve may be a horizontal slide type in which it moves horizontally instead of a vertical slide type in which it moves vertically. Further, similarly to the first embodiment, the upper end of the plate valve is fixed to the upper part of the upper water chamber partition plate, the lower end is connected to a rope, and the upper end of the plate valve is rotated as a fulcrum by pulling the rope. There is no limitation that the moving system may be used.

In the second embodiment of the present invention, as described above, the bypass flow rate is automatically adjusted according to the cooling temperature of the coke oven gas and the temperature of the cooling water after the heat exchange. Alternatively, manual operation may be performed instead of automatic operation.

[0077]

EXAMPLES Experimental Example 1 In the COG cooling apparatus of the present invention shown in FIGS. 1 and 2, COG flow rates depending on the season (seawater temperature for cooling) change are shown in Tables 1 to 3 below. Based on the COG flow rate in such changes in the season (seawater temperature for cooling), the COG amount / temperature (CO
(G inlet temperature and outlet temperature), pressure, saturated vapor pressure, etc. to calculate the saturation enthalpy of COG, and the required cooling from the cooling water temperature (the temperature difference between the temperature of the cooling water before heat exchange and the temperature after heat exchange). The water flow rate was determined. Specifically, as described above, the required cooling water flow rate is calculated by inputting numerical values such as COG amount / temperature, pressure, saturated vapor pressure, cooling water temperature, etc. into the computer in which the heat transfer calculation formula is programmed. (See the heat transfer calculation formula above).

In the first embodiment, the indirect cooling device is operated at the obtained cooling water flow rate, the cooling temperature of COG is a predetermined temperature of 50 ° C. or higher at which naphthalene does not substantially precipitate, and the outlet temperature of the cooling water does not easily corrode at high temperature. The heat exchange area of the cooling pipe was adjusted so that the predetermined temperature was 70 ° C. or lower. In particular,
As a method of adjusting the heat exchange area of the cooling pipe (method of invalidating the heat exchange area), a method of manually placing a rubber sheet (shielding plate) in the upper and second water chambers of FIGS. 1 and 2 is used. It was

Specifically, the COG flow rate measured by a gas flow meter installed on the discharge side of the gas blower and a seawater inlet thermometer installed on the seawater supply pipe (2000 per season)
0, 25000 and 30,000 Nm ³ / h) and cooling water temperature (10 depending on the season, respectively,
According to the heat transfer calculation formula shown above, the flow rate of the cooling water flowing through the cooling pipe 111 was calculated and adjusted to the cooling water flow rate (see Table 1). ).

Next, the indirect cooling device is operated at the obtained cooling water flow rate, and the naphthalene does not substantially deposit the COG cooling temperature (in FIG. 2, the temperature measured by the COG outlet thermometer 129 provided near the COG outlet). Above a predetermined temperature (5 in this embodiment)
The temperature was 5 ° C. ) And the cooling water outlet temperature (in FIG. 2,
The temperature measured by a seawater outlet thermometer 131 provided in the vicinity of the seawater outlet is equal to or lower than a predetermined temperature at which high temperature corrosion is unlikely to occur (in this example, it was set to 55.7 to 69.8 ° C as shown in Table 1).
As described above, by further blocking a part of the cooling pipe 111 with a rubber sheet, the cooling water is prevented from flowing, and an excessive heat exchange area is shielded and adjusted to the actually required heat exchange area. . Specifically, when the cooling water outlet temperature exceeds 70 ° C, the cooling pipe inlet is closed with a rubber sheet until the cooling water temperature is 70 ° C or lower and the COG cooling temperature reaches 55 ° C. Table 1 shows the cooling water temperature in a stable state where the incoming seawater is cut off at a temperature of 70 ° C or less, the required heat transfer area (heat exchange area) and the heat transfer area reduction rate at that time. .

Similarly, in Comparative Example 1, in the case where the heat exchange area is not changed, the COG outlet temperature is equal to or higher than a predetermined temperature at which naphthalene is not substantially deposited (55 ° C. in this Comparative Example 1).
And Table 2 shows the calculation of the change in the seawater outlet temperature when the seawater flow rate is adjusted. Table 2
As can be seen from the above, when the seawater temperature decreases or the COG flow rate decreases due to seasonal changes, it is not possible to prevent the seawater outlet temperature from exceeding 70 ° C even if the seawater flow rate is adjusted. Recognize.

Further, as Comparative Example 2, the COG flow rate was changed from 30,000 Nm ³ / h to 50 without changing the heat exchange area.
Table 3 shows the calculation of the change in the seawater outlet temperature when the COG outlet temperature is adjusted to decrease from 55 ° C to 2.5 ° C in response to the decrease of 00 Nm ³ / h. As can be seen from Table 3, when the seawater temperature decreases or the COG flow rate decreases due to seasonal changes, the seawater outlet temperature is 7 even if the seawater flow rate is adjusted.
It turns out that it cannot prevent exceeding 0 degreeC.

[0083]

[Table 1]

[0084]

[Table 2]

[0085]

[Table 3]

For various conditions such as COG amount and cooling water temperature,
COG when only the flow rate of cooling water is changed without changing the heat exchange area (Comparative Example) and when the heat exchange area is changed (Invention)
Shows the calculation results of the outlet temperature and the cooling water outlet temperature.

[0087]

In the conventional cooling method and cooling device, the cooling capacity (number and length of cooling pipes) is fixed,
No consideration has been given to these, and by adjusting the number of operating cooling devices equipped with multiple units and adjusting the flow rate of seawater that is cooling water, changes in seawater temperature and coke production due to the season of seawater It corresponded to the change in the COG generation amount due to the change. On the other hand, in the cooling method and the cooling device of the present invention, it is not necessary to adjust the operating number of the cooling device, and the cooling capacity that has been left unresolved because it has been fixed in the past is reconsidered and low. It was found that the heat exchange area can be nullified by blocking or bypassing the excessive flow of seawater to the heat transfer tube during load operation. As a result, it is possible to provide a flexible device capable of coping with the operating range of the indirect gas cooling device, particularly a low load region, and a method using the same.

Therefore, the work of suspending and restarting the equipment by the conventional method for adjusting the number of operating bases becomes unnecessary.

Further, by appropriately controlling the operating temperature, it is possible to avoid the clogging of the outlet side cooling pipe due to the adhesion of naphthalene. In addition, the corrosion rate of the cooling pipe and the seawater outlet drainage pipe due to seawater can be significantly reduced. As a result, the number of cleaning operations for removing naphthalene adhering to the cooling pipe can be significantly reduced. Further, the effect of being able to significantly extend the life of the cooling pipe due to high temperature corrosion is exhibited.

[Brief description of drawings]

FIG. 1 shows a representative embodiment 1 of a COG cooling method according to the present invention, which is an indirect gas cooling facility provided with an opening / closing mechanism of a rubber sheet shielding plate for adjusting a heat exchange area (shielding means for a cooling pipe). FIG.

FIG. 2 is a cross-sectional view of the indirect gas cooling facility taken along the line AA of FIG.

FIG. 3 shows a second embodiment of the COG cooling method according to the present invention, which is an indirect gas cooling facility in which a bypass passage of cooling water whose flow rate can be adjusted is provided in a cooling device for adjusting a heat exchange area. FIG.

4 is a cross-sectional view of the indirect gas cooling equipment taken along the line BB of FIG.

FIG. 5 is a detailed view of the shielding part in the opening / closing mechanism of the rubber sheet shielding plate of FIGS. 1 and 2, wherein the curved rubber sheet closes the inflow port at the end lifting height of the rubber sheet shielding plate. Fig. 5 (a) shows a state in which the number of cooling pipes is adjusted, and Fig. 5 (a) shows a state in which the cooling pipe is closed by loosening the rope, and the end of the rubber sheet is lowered to the bottom. FIG. 5B is a top view showing a state in which all the cooling pipe inflow ports that can be closed by the rubber sheet are closed (the entire rubber sheet is in close contact with the upper tube sheet), and FIG. It is a side sectional view.

FIG. 6 is a detailed view of the shielding portion in the opening / closing mechanism of the rubber sheet shielding plate of FIGS. 1 and 2, wherein the curved rubber sheet closes the inflow port at the end lifting height of the rubber sheet shielding plate. FIG. 6 (a) shows how to adjust the number of cooling pipes. FIG. 6 (a) shows a case where a rope is pulled to pull up an end portion of a rubber sheet and a curved rubber sheet can close the inlet 50 of the cooling pipe. FIG. 7B is a top view showing a state in which% is closed, and FIG.
FIG. 7 is a side sectional view of FIG.

FIG. 7 is a drawing schematically showing a typical embodiment of a conventional COG cooling device, which is a combination of an indirect cooling type cooling device and a direct cooling type cooling device. is there.

FIG. 8 is a drawing showing the relationship between the temperature of COG and the saturated concentration of naphthalene.

[Explanation of symbols]

101 ... COG inlet, 103 ... COG outlet, 105 ... Seawater inlet, 106 ... Lower water chamber, 106a ... 1 lower water chamber, 106b ...
Lower water chamber 2, 106c ... Lower water chamber 3
106d ... 4 lower water chambers, 107 ... seawater outlet,
108 ... upper water chamber, 108a ... upper water chamber 1 room,
108b ... Upper water chamber 2 chambers, 108c ... Upper water chamber 3
Chamber, 109 ... Cooling device main body, 111 ... Cooling tube (heat transfer tube), 113 ... Lower tube plate, 115 ... Gas side partition plate, 115a ... Upper gas side partition plate, 115b ... Lower gas side partition plate, 117 ... Upper tube Plate, 119 ... Lower water chamber partition plate, 121 ... Upper water chamber partition plate, 123 ... Rubber sheet,
124, 142 ... pulley, 125 ... rubber sheet lifting device,
126, 144 ... Rope, 127 ... Rubber sheet fixing bracket, 129 ... COG outlet thermometer, 131 ... Seawater outlet thermometer, 133 ... Flow control valve, 135
… Seawater (cooling water) supply pipe, 136… COG supply pipe, 137… Cooling water discharge pipe, 138… CO
G discharge pipe, 139 ... Control device,
141 ... Plate valve, 143 ... Plate valve lifting device,
145 ... Seawater bypass port, 701 ... Indirect cooling type cooling device, 703 ... Direct cooling type cooling device, 705 ... Blower, 707 ... Heat exchanger (H
E).

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshifumi Motouchi             2-6-3 Otemachi, Chiyoda-ku, Tokyo New Japan             Steelmaking Co., Ltd. (72) Inventor Tomoyuki Hironaka             1-1 Tobata-cho, Tobata-ku, Kitakyushu, Fukuoka             Inside the Yawata Works of Hontan Works (72) Inventor Shintaro Ikemoto             1-1 Tobata-cho, Tobata-ku, Kitakyushu, Fukuoka             Inside the Yawata Works of Hontan Works F-term (reference) 3L103 AA20 AA25 BB02 CC02 CC27                       DD08

Claims (9)

[Claims] 1. A method for cooling a coke oven gas in which seawater is passed through a large number of cooling pipes to indirectly cool the coke oven gas, the flow rate of the cooling water flowing through the cooling pipes depending on the amount of the coke oven gas and the cooling water temperature. In addition, the heat exchange area is adjusted by shielding a part of the cooling pipe to adjust the cooling temperature of the coke oven gas to a predetermined temperature or higher at which naphthalene does not substantially precipitate, and the temperature of the cooling water after heat exchange is subject to high temperature corrosion. A method for cooling a coke oven gas, wherein the temperature is set to a predetermined temperature or less at which it hardly occurs. 2. A method of adjusting the heat exchange area of a cooling pipe is provided with a rubber shield plate that can be automatically opened and closed from the outside in a part of the cooling pipe, and the cooling temperature of the coke oven gas and the heat of the cooling water. The cooling method according to claim 1, wherein the heat exchange area of the cooling tubes is adjusted by automatically opening and closing the flow paths of some of the cooling tubes according to the temperature after the replacement. 3. A method for cooling a coke oven gas in which seawater is passed through a large number of cooling pipes to indirectly cool the coke oven gas, and a part of the cooling water is cooled according to the amount of the coke oven gas and the temperature of the cooling water. A coke oven characterized by being bypassed to the water outlet side so that the cooling temperature of the coke oven gas is set to a predetermined temperature or higher at which naphthalene does not precipitate, and the temperature of the cooling water after heat exchange is set to a predetermined temperature or less at which high temperature corrosion does not easily occur. Gas cooling method. 4. The bypass method comprises providing a flow rate control valve capable of automatically controlling the opening of a bypass flow passage from the outside, and performing the bypass by the cooling temperature of the coke oven gas and the temperature after heat exchange of cooling water. The cooling method according to claim 3, wherein the flow rate is automatically adjusted. 5. A coke oven gas cooling device for indirectly cooling coke oven gas by passing seawater through a large number of cooling pipes, wherein the coke oven gas outlet temperature is equal to or higher than a predetermined temperature at which naphthalene does not substantially precipitate, and A coke oven gas cooling device, which is provided with adjusting means for adjusting the temperature of the cooling water outlet to a predetermined temperature or less at which hot corrosion does not easily occur. 6. The means for adjusting, as means for adjusting, the flow rate of cooling water flowing through the cooling pipe in accordance with the amount of coke oven gas and the temperature of cooling water inlet, and further, a part of the cooling pipe is shielded so as to reduce the heat exchange area. The coke oven gas cooling device according to claim 5, further comprising: a means for adjusting the coke oven gas. 7. As a means for adjusting the heat exchange area of the cooling pipe, a part of the cooling pipe is provided with a rubber shield plate that can be automatically opened / closed from the outside, and the temperature is adjusted by the coke oven gas outlet temperature and the cooling water outlet temperature. The coke oven gas cooling device according to claim 6, wherein an automatic opening / closing mechanism for a part of the cooling pipe flow path using a shielding plate is provided. 8. The adjusting means is provided with means for bypassing a part of the cooling water to the cooling water outlet side according to the temperature of the coke oven gas outlet and the cooling water outlet. Coke oven gas cooling device as described. 9. The bypass means is provided with a bypass flow path for bypassing a part of the cooling water to the cooling water outlet side, and a flow rate control valve capable of automatically operating the opening degree of the bypass flow path from the outside. The coke oven gas cooling device according to claim 8, wherein