JPS59110735A - Method for cooling coil - Google Patents

Abstract

PURPOSE:To perform the control of an annealed cold rolled coil over an optimum cooling time while preventing the dew condensation on the coil surface, by controlling a coil cooling speed while comparing the measured temp. of the annealed cold rolled coil with the estimated temp. of a cooling curve at the temp. measuring time. CONSTITUTION:A microcomputer 6 receives the output signal of a thermocouple 7 for detecting the temp. of a coil 1 in a cooling zone 1 as input information to control a solenoid valve 5 and determines a cooling curve by coil information preliminarily imparted from a line computer 8 when cooling is started. That is, the computer 8 determines the parameter of a cooling formula of a time and a temp. by coil information and, at the same time, determines a cooling completion expected time. Thereafter, the taken-in real temp. of the coil 1 is compared with the estimated temp. read from the cooling curve at the temp. measuring time and, when the deviation therebetween exceeds tolerant difference, the computer 6 opens and closes a damper 3 to perform the temp. control of the coil 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coil cooling control method that optimally adjusts the cooling rate and prevents dew condensation from forming on the coil surface.

The cold-rolled coil goes through an annealing-cooling-skin bath process as shown in Figure 1, but the coil temperature at the end of annealing is 1.
The temperature will be approximately 10°C to 130°C. Therefore, the material is cooled down to 40° C. to 50° C. in a cooling yard before being passed through the next skin pass.

However, if the coil is cooled without air conditioning, if the cooling rate is too fast or if the surrounding relative humidity is too high, condensation may occur on the coil surface. This condensation causes rust. Conventionally, in order to avoid this condensation phenomenon, the cooling yard was partitioned with walls such as insulation materials, dry cooling air was blown into the yard, air conditioning was managed for the entire cooling yard, and the temperature and humidity of the air blown from the coils at each base were controlled. However, the time required to cool a coil varies depending on the weight, number of turns, width, number of stacks, steel type, etc. of the coil. Therefore, if the method of statically predicting the cooling completion time at the start of cooling with the aim of making the process of annealing → cooling → pass/pass flow smoothly in terms of logistics, the temperature at the time of cooling completion will vary, and re-cooling or , this will lead to variations in gap/pass temperatures.

It should be noted that if the temperature and humidity in the air-conditioning yard are adequately controlled, rust prevention, which is the original purpose of the air-conditioning yard, can be achieved, but from a logistics perspective, the residence time of the coil in the cooling yard is need to be kept to a minimum.

An object of the present invention is to provide a coil cooling method that allows distribution and process control to be performed with an optimal cooling time while preventing dew condensation on the coil surface.

The present invention determines a cooling formula based on the initial temperature of the coil in the cooling yard and other coil information, predicts the cooling completion time, and then measures the coil temperature continuously or on a continuous basis. The value is taken in and compared with the cooling type temperature at that time, and if the error exceeds the tolerance, the blown air is controlled by closing the valve/bar, or if control is not possible, the air is closed. This information is used as information for changing the pass command set, and allows management to maintain the optimum cooling time while preventing dew condensation on the coil surface from the end of annealing to the start of the skin pass. Furthermore, the present invention aims to realize the contents shown in the following sections.

(1) Strictly adhere to the cooling completion time predicted at the start of cooling.

(2) Do not change the skin pass command set based on the predicted cooling completion time as much as possible.

(3) Increase the accuracy of the cooling completion time by putting the true temperature of the coil on the target cooling curve by controlling the cooling air volume.

Note that the cooling formula is calculated as follows. When the various quantities are defined as follows, the heat conduction equation is given by equation (1).

Q: Silence'', C: Heat capacity, Q- 1, -t-Ash(T-To) zze(1) (However, Q-C-W-T.) Solving equation (1), we get However, in reality, when the correction value α due to the disturbance is determined experimentally, the following is obtained, and this is used as the cooling formula. Note that α is a function of the coil width, plate thickness, number of stages, etc.

Furthermore, to calculate the cooling completion time, the blown air temperature T and coil initial temperature 1i'r in Equation (3) can be easily obtained as data.
3) By substituting T in the equation, the required time t can be calculated, and by adding this t to the cooling start time, the cooling completion time can be calculated. 1. Figure 2 shows an embodiment of the present invention. This is a block diagram showing the following.

Cooling of the coil 1 in the cooling sea/ is carried out by cooling air supplied from the tl 175E controlled by the air/par 3 in the duct z. The damper 3 is controlled by an air cylinder 4 via a beam/branch member, and its operation is controlled by a solenoid valve 5 and a microcomputer 6.
This is done by controlling the The microcomputer 6 controls the solenoid valve 5 using the output signal of the thermocouple 7 that detects the temperature of the coil 1 at the cooling seam as input information, and also controls the cooling curve based on the coil information given in advance from the line computer 8 at the start of coil cooling. decide. That is, at the start of cooling, the lie/computer 8 determines the parameters of the cooling formula, such as time and temperature, based on coil information such as the weight, width, and number of stacked coils, and at the same time determines the expected cooling completion time.

After that, the true temperature of the coil taken in as a pre-puffer is compared with the predicted temperature at that time read from the cooling curve, and when the polarization exceeds the tolerance, a command from the microcomputer 6 causes the coil base to turn bar 3
Opens and closes to control the amount of cooling air and control the temperature of the coil.

In general, the shorter the coil cooling time, the better, so the damper 3 under the coil base is cooled fully open.

FIG. 3 is a cooling curve according to the present invention, and the present invention will be specifically explained based on this.

In FIG. 3, the predicted cooling curve for the coil that started cooling at temperature TA and time tA is shown by solid lines A-B and -C.
It is determined that Next, if the true temperature of the coil at time tB is within TBO or its tolerance, cooling continues. If the true temperature is TBI, damper 3
is already fully opened, so the cooling completion time is changed from tc to t.
Correct it to c'.

This information is transmitted to the upper line computer 8 and changes the skin pass command line from that computer. Here, with skin pass instruction silk, the order of charging into the skin pass mill is from wide to narrow coils due to roll wear, and the same roll cannot be used unless the coils have the same finished surface roughness. . The command line determines the charging 111 of the coil into the skin pass mill by taking these into consideration.

If the true temperature is TB2, the evening doper is operated in the closing direction, and the flow rate of the cooling air is controlled to bring the coil temperature closer to the A-BO-C curve. The opening degree of the damper 3 at this time is adjusted according to the magnitude of (TB□T'B2). With the above control, the true temperature and the temperature obtained by the cooling method are compared at certain time intervals, and if the temperature falls within the tolerance range, the damper 3 is opened again to increase the cooling rate. Therefore, in this case, the skin pass command line using the cooling completion time predicted at the start of cooling is not changed.

As is clear from the above, according to the present invention, by controlling the cooling completion time of the coil from the predetermined time, it is possible to prevent dew condensation on the coil surface and to perform logistics and process logistics at the optimum cooling time. Can be done.

[Brief explanation of the drawing]

FIG. 1 is a physical distribution diagram of a cold rolled coil, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a cooling characteristic diagram according to the present invention. 2... Actuator, 3... Damper, 4... Air cylinder, 5... Solenoid valve, 6... Microcomputer, 7... Thermocouple, 8... Line computer. Agent Tatsuyuki Unuma (and 2 others) Figure 1 Figure 3

Claims (1)

[Claims] (1) In a coil cooling management system that cools an annealed cold-rolled coil before sending it to the skin pass process, a cooling curve is determined based on data regarding the coil, and the predicted temperature at the time determined from the curve and the measured temperature of the coil are determined. A coil cooling method characterized in that the cooling rate is controlled so that the actual coil temperature is on the cooling curve while being compared.