JP4647925B2 - Cooling system - Google Patents

Description

  The present invention relates to a cooling device that cools a workpiece heated to a predetermined temperature along a predetermined temperature pattern.

In a heat treatment furnace provided with a heating zone and a cooling zone, there are two types of methods for cooling a material to be processed such as a metal strip coil heated to a predetermined temperature in the heating zone in the cooling zone, for example, as shown below. There is a way.
The first method is described in, for example, Patent Document 1, and as shown in FIG. 3, the cooling zone C is divided into a plurality of cooling chambers R by the partition door 6, and cooling is performed for each cooling chamber R. A cooling means 10 for supplying air and an exhaust means 30 for exhausting the air in the cooling chamber R are provided. And cooling air is supplied to each cooling chamber R, the temperature of each cooling chamber R is reduced in steps along the conveyance direction of the to-be-processed material 2, and the to-be-processed material 2 is conveyed, and each cooling chamber R is set. The material to be treated 2 is directly cooled while passing through in order.

Further, the second method virtually divides the cooling zone C into a plurality of cooling chambers along the conveyance direction of the material to be processed, and provides a cooling pipe through which a refrigerant such as cooling air flows for each divided cooling chamber, The flow rate of the refrigerant is controlled for each cooling chamber. And it cools indirectly by heat exchange, conveying a to-be-processed material and passing each cooling chamber in order.
Japanese Patent No. 2774011 (FIG. 1)

However, in the first method, a large number of partition doors 6 are required to divide the cooling zone C into a plurality of cooling chambers R, but the partition doors 6 have sufficient sealing properties and can be raised and lowered. It needs to be made of refractory. Furthermore, since equipment such as the exhaust means 30 and the exhaust damper is required for each cooling chamber R, there is a problem that the equipment cost increases.
In the second method, since each cooling chamber is not physically divided, adjacent cooling chambers cause air to enter and exit from each other. For this reason, there is a problem that heat interference occurs between adjacent cooling chambers and cooling efficiency decreases. Furthermore, the cooling chamber in which the material to be treated is transferred becomes a high-temperature environment, and the cooling pipe and supporting parts are thermally deformed due to high temperature or damaged due to oxidation thinning due to high-temperature oxidation, thus increasing the part cost and repair cost. There is a problem. Moreover, there is also a problem that the operating rate of the equipment is lowered due to the equipment stoppage due to the repair work of the cooling pipe and the supporting parts. Therefore, in order to protect the cooling pipe from the high temperature environment of the cooling chamber, it is necessary to keep a certain amount of refrigerant flowing through the cooling pipe, and thus there is a problem that the temperature control range of the cooling chamber is limited.
The present invention has been made paying attention to the above-described problems, and is capable of preventing a decrease in the cooling efficiency of the material to be processed, reducing the equipment cost, and expanding the control range of the cooling temperature. It is an object to provide an apparatus.

In order to solve the above-mentioned problems, the invention described in claim 1 of the present invention includes a cooling section that is provided along the conveying direction of the material to be processed and forms a sealed space,
The cooling zone is composed of a plurality of cooling chambers divided by a shielding plate having a size that does not hinder the conveyance of the material to be processed along the conveyance direction of the material to be processed , and is heated to a predetermined temperature. A cooling device that cools a treatment material along a predetermined temperature pattern while passing through the plurality of cooling chambers,
Cooling means for supplying cooling air for cooling the material to be treated for each of the cooling chambers, and exhausting the air in the cooling area so that the air in the plurality of cooling chambers flows along the conveying direction of the material to be treated. And an exhaust means for
The exhaust means exhausts air in the cooling area only from the cooling chamber on the most downstream side.

According to the present invention, since the air in all the cooling chambers flows along the conveyance direction of the material to be processed, the thermal interference generated between adjacent cooling chambers can be reduced, and the cooling efficiency of the material to be processed can be prevented from being lowered. It becomes.
In addition, according to the present invention, the air in the cooling area is exhausted only from the cooling chamber on the most downstream side, so that the air in all the cooling chambers can flow along the conveyance direction of the workpiece.
In addition, according to the present invention, since heat interference generated between adjacent cooling chambers is further reduced, it is possible to prevent a decrease in cooling efficiency of the material to be processed.
Here, “virtual division” means to divide the cooling area into a plurality of cooling chambers that can be ventilated to each other, and is not physically shielded completely. In addition, the “predetermined temperature pattern” refers to setting the cooling temperature of the material to be processed (hereinafter referred to as a set temperature) for each cooling chamber, and setting the set temperature of each cooling chamber along the conveyance direction of the material to be processed. It is a pattern that gradually decreases.

Next, the invention described in claim 2 is the invention described in claim 1, further comprising supply amount control means for controlling the supply amount of the cooling air to each cooling chamber,
The supply amount control means controls the supply amount of cooling air to each cooling chamber based on the heat removal amount in the target cooling chamber and the heat capacity brought in from the upstream cooling chamber. .
According to the present invention, it is possible to accurately cool a material to be processed to a target temperature.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to prevent the fall of the cooling efficiency of a to-be-processed material, to reduce facility cost etc., and to expand the control range of cooling temperature.

Embodiments of the present invention will be described with reference to the drawings.
First, the configuration of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected and demonstrated to the same part as what was shown in FIG.
As shown in FIG. 1, the cooling device 1 of the present invention includes a cooling zone C, a cooling means 10, a supply amount control means 20, and an exhaust means 30.
The cooling zone C of the present embodiment is provided continuously with the heating zone H that heats the workpiece 2 to a predetermined temperature along the conveyance direction of the workpiece 2. In addition, the cooling zone C includes a plurality of virtual sections from the first chamber on the most upstream side to the nth chamber on the most downstream side, with the position indicated by the broken line in the figure along the conveyance direction of the workpiece 2. It is divided into cooling chambers R. (Hereinafter, the cooling chamber R ₁ of the first chamber, the first n chamber shown and the cooling chamber R _n, shown as well with respect to the cooling chambers R between the first chamber to n-th compartment). Adjacent cooling chambers R can be ventilated with each other, and a fixed shielding plate 4 is provided between the adjacent cooling chambers R. The shielding plate 4 is lowered from the ceiling to a height that does not hinder the conveyance of the workpiece 2.

  Partition doors 6 are respectively provided at the most upstream part and the most downstream part along the conveying direction of the workpiece 2 in the cooling zone C. The partition door 6 is formed of a refractory material, has sufficient sealing properties, and can be raised and lowered. When the partition door 6 is raised, the workpiece 2 can be carried into and out of the cooling zone C. When the partition door 6 is lowered, the cooling zone C is sealed.

  The cooling means 10 includes a cooling fan 12, a cooling control valve 14, and a blowing nozzle 16. The cooling fan 12 generates cooling air that cools the workpiece 2, and this cooling air is supplied to each cooling chamber R from a blowing nozzle 16 provided in each cooling chamber R via a cooling control valve 14. The The cooling control valve 14 is provided in each cooling chamber R, and controls the amount of cooling air supplied to each cooling chamber R based on a signal transmitted from the supply amount control means 20.

The temperature sensor 18 is provided in each cooling chamber R, detects the temperature T of each cooling chamber R, and outputs it to the supply amount control means 20.
In each cooling chamber R, the supply amount control means 20 sets the material 2 to be processed, the inside of the cooling chamber R, and the inner wall of the cooling chamber R (hereinafter referred to as the material 2 to be processed) in a predetermined temperature pattern. The supply amount of the cooling air to each cooling chamber R is calculated so that the temperature is reached. The calculated supply amount of cooling air is transmitted as a supply amount control signal S1 to the cooling control valve 14 provided in each cooling chamber R and the exhaust amount control means 38.

  Here, the calculation of the supply amount of the cooling air to each cooling chamber R is performed based on the heat removal amount in the cooling chamber R supplying the cooling air and the heat capacity brought in from the upstream cooling chamber R. The amount of heat removal in the cooling chamber R that supplies the cooling air is calculated based on the difference in set temperature between the cooling chamber R that supplies the cooling air and the upstream cooling chamber R and the specific heat of the workpiece 2. The heat capacity brought in from the upstream cooling chamber R depends on the temperature difference between the cooling chamber R that supplies cooling air and the upstream cooling chamber R, and the cooling chamber that supplies cooling air from the upstream cooling chamber R. Calculated based on the amount of air brought into R. The amount of air brought into the cooling chamber R that supplies cooling air from the upstream cooling chamber R is calculated from, for example, the amount of cooling air supplied to the upstream cooling chamber R.

  If the feedforward control as described above is performed, for example, the furnace temperature can be accurately controlled even when the heat load due to the temperature, weight, etc. of the material to be processed 2 is greatly changed. In the actual operation, the furnace temperature of the cooling chamber R is simply calculated by designing the cooling means 10 such as the cooling control valve 14 and the pipe diameter based on the required control amount of the supply air. It is also possible to perform feedback control in which the amount of cooling air supplied is controlled so as to reach the target value.

The storage unit 22 stores a set temperature for each cooling chamber R in a predetermined temperature pattern. The predetermined temperature pattern can be changed as appropriate.
The exhaust unit 30 includes an exhaust fan 32, an exhaust control valve 34, an exhaust port 36, and an exhaust amount control unit 38. The exhaust fan 32 exhausts the air in all the cooling chambers R flowing from the exhaust port 36 via the exhaust control valve 34. The exhaust control valve 34 controls the exhaust amount of air in all the cooling chambers R based on the signal transmitted from the exhaust amount control means 38. Exhaust port 36, only provided in the cooling chamber R _n.

The exhaust amount control means 38 calculates the exhaust amount of all the cooling chambers R according to the supply amount of the cooling air to each cooling chamber R, and transmits the calculated exhaust amount to the exhaust control valve 34 as the exhaust amount control signal S2. To do. The exhaust amount of all the cooling chambers R may be equal to the amount of cooling air supplied to each cooling chamber R, or may be an amount increased or decreased from the amount of cooling air supplied to each cooling chamber R.
Further, if the feedforward control as described above is performed for the exhaust amount, the control can be performed with higher accuracy. However, a simulation calculation is performed at the time of designing the cooling device 1 to design the capability of each exhaust unit 30. In actual operation, it is possible to simply perform feedback control in which the displacement is controlled so that the furnace pressure in the cooling chamber R becomes a target value.

Next, the operation and effect of the cooling device 1 having the above configuration will be described. The control method described below is an example, and the present invention is not limited to this.
The supply amount control means 20 includes a temperature T _C of a cooling chamber R (hereinafter referred to as a cooling chamber R _C ) that is a control target of a cooling air supply amount, and a cooling chamber R (hereinafter referred to as a cooling chamber) in front of the cooling chamber R. based on the temperature difference between the temperature T _C-1 of the chamber showing the R _C-1), the amount of air brought into the cooling chamber R _C from the cooling chamber R _C-1, brought from the cooling chamber R _C-1 The calculated heat capacity is calculated. Then, based on the dissipation heat amount calculated heat capacity and the cooling chamber R _C, in the cooling chamber R _C as the material to be treated 2 or the like is the set temperature, and calculates the supply amount of the cooling air into the cooling chamber R _C, This supply amount of cooling air is transmitted as a supply amount control signal S1 to the cooling control valve 14 provided in the cooling chamber _RC and the exhaust amount control means 38.

Cooling chamber R _C cooling control valve 14 provided in the controls the supply amount of the cooling air into the cooling chamber R _C. The cooling chamber _RC is supplied with an amount of cooling air necessary for cooling the workpiece 2 and the like to the set temperature. Therefore, in the cooling chamber R _C , the air brought from the cooling chamber R _C-1 is also cooled to the set temperature together with the material to be processed 2 and the like, so that the cooling efficiency of the material to be processed 2 and the like is prevented from being lowered. .
In the cooling chamber R ₁ on the most upstream side of all the cooling chambers R, the supply amount of the cooling air is calculated only based on the heat removal amount in the cooling chamber R ₁ , and the processing object 2 and the like are cooled to the set temperature. Therefore, a necessary amount of cooling air is supplied.

  The exhaust amount control means 38 calculates the exhaust amount of all the cooling chambers R according to the amount of cooling air supplied to each cooling chamber R, and transmits an exhaust amount control signal S2 to the exhaust control valve 34. When the exhaust amount control signal S <b> 2 is transmitted to the exhaust control valve 34, the air in all the cooling chambers R is exhausted from the exhaust port 36, and the air in all the cooling chambers R flows along the conveyance direction of the workpiece 2. Therefore, an air flow is generated from the cooling chamber R having a high set temperature to the cooling chamber R having a low set temperature. For this reason, the heat interference which arises between adjacent cooling chamber R falls, and the fall of the cooling efficiency of the to-be-processed material 2 grade | etc., Is prevented. In addition, since the exhaust amount of the air in all the cooling chambers R is controlled according to the amount of cooling air supplied to each cooling chamber R, the atmospheric pressure in all the cooling chambers R can be arbitrarily controlled. It becomes possible to prevent the cooling efficiency of the treatment material 2 and the like from being lowered.

Furthermore, since the heat interference generated between the adjacent cooling chambers R is further reduced by the shielding plate 4, it is possible to prevent the cooling efficiency of the material 2 to be processed from being lowered.
In addition, when a predetermined temperature pattern has a big difference in the set temperature of each cooling chamber R, for example, the supply amount of the cooling air to each cooling chamber R may be calculated by the following method. In this method, the supply amount of cooling air to each cooling chamber R is calculated in advance, and the supply amount of cooling air to each cooling chamber R is again determined based on this supply amount and the temperature of each cooling chamber R. Is to be calculated. According to this method, even if there is a large difference in the set temperature of each cooling chamber R, the amount of cooling air supplied to each cooling chamber R becomes an appropriate amount. Decrease is prevented.

In the present embodiment, the exhaust port 36 is provided only in the cooling chamber R _n , but the exhaust port 36 is also provided in the cooling chamber R other than the cooling chamber R _n , and the exhaust port 36 is provided in the cooling chamber R _n. The exhaust may be assisted. At this time, the exhaust amount from the exhaust port 36 provided in the cooling chamber R other than cooling chamber R _n is less than the exhaust amount from the exhaust port 36 provided in the cooling chamber R _n, air total cooling chamber R Flow along the conveying direction of the material 2 to be processed.

Although a temperature sensor 18 for each cooling chamber R, for example, the cooling chamber includes a temperature sensor 18 only R ₁ and cooling chamber R _n, the temperature of the temperature T ₁ and cooling chamber R _n of the cooling chamber R ₁ The temperature of each cooling chamber R other than the cooling chamber R ₁ and the cooling chamber R _n may be estimated by detecting T _n .
Furthermore, before the workpiece 2 is carried into the cooling zone C, the cooling chambers R and the inner walls of the cooling chambers R may be cooled to the set temperature in advance.

The material to be treated was cooled by a cooling method using a cooling device having the same configuration as that described in this embodiment. As a comparative example, the material to be treated was cooled by the same cooling method as the second method described in the background art.
As a result, as shown in FIG. 2, it was confirmed that the cooling method of the example of the present invention had a wider control range of the cooling temperature than the cooling method of the comparative example.

Moreover, since the cooling method of the present invention directly cools the material to be treated by the cooling air, the cooling efficiency of the material to be treated is higher than the cooling method of the comparative example. Therefore, even when the motor capacity of the cooling fan is reduced to about 1/6 as compared with the cooling method of the comparative example, the cooling can be performed more rapidly than the cooling method of the comparative example.
Furthermore, in the cooling method of the comparative example, it is necessary to continuously flow a certain amount of refrigerant through the cooling pipe, and there is a limit to the slow cooling performance. However, in the cooling method of the present invention, the supply of cooling air to any cooling chamber is stopped. Therefore, the slow cooling performance is improved as compared with the cooling method of the comparative example.

It is the schematic which shows the cooling device of this invention. It is a comparison figure of the control range of the cooling temperature by the cooling method of this invention example and a comparative example. It is the schematic which shows the conventional cooling device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cooling device 2 Material to be processed 4 Shielding plate 6 Partition door 10 Cooling means 12 Cooling fan 14 Cooling control valve 16 Outlet nozzle 18 Temperature sensor 20 Supply amount control means 22 Storage part 30 Exhaust means 32 Exhaust fan 34 Exhaust control valve 36 Exhaust port 38 Exhaust amount control means C Cooling zone H Heating zone R Cooling chamber S1 Supply amount control signal S2 Exhaust amount control signal T Temperature of cooling chamber R

Claims (2)

Provided with a cooling zone provided along the conveying direction of the material to be processed and forming a sealed space;
The cooling zone is composed of a plurality of cooling chambers divided by a shielding plate having a size that does not hinder the conveyance of the material to be processed along the conveyance direction of the material to be processed , and is heated to a predetermined temperature. A cooling device that cools a treatment material along a predetermined temperature pattern while passing through the plurality of cooling chambers,
Cooling means for supplying cooling air for cooling the material to be treated for each of the cooling chambers, and exhausting the air in the cooling area so that the air in the plurality of cooling chambers flows along the conveying direction of the material to be treated. And an exhaust means for
The cooling device according to claim 1, wherein the exhaust means exhausts air in the cooling section only from the cooling chamber on the most downstream side. Supply amount control means for controlling the supply amount of the cooling air to each cooling chamber,
2. The supply amount control means controls the supply amount of cooling air to each cooling chamber based on a heat extraction amount in a target cooling chamber and a heat capacity brought in from an upstream cooling chamber. The cooling device described in 1.

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