JPS58120741A - Continuous quenching device for steel plate - Google Patents

Abstract

PURPOSE:To control a cooling capacity very effectively extending over a wide range by a very simple means, by providing a bubble generating means which can be controlled, in cooling water in a water storage tank, in a titled device for making a steel plate pass through into the water storage tank. CONSTITUTION:Impellers 32, 34 in a water storage tank 10 moves cooling water in the vicinity of the surface of a steel plate to be quenched 12, in the moving or opposite moving direction of the plate 12. In this case, compressed air is blown into impeller boxes 56, 58 through main pipes 90, 92 and branch pipes 94, 96. This air becomes bubble 100,is mixed uiformly with cooling water by rotation of the impellers 32, 34, and the cooling water containing the bubbles 100 is moved by the impellers 32, 34 as mentioned above. In this way, the plate 12 is cooled, but since the bubbles 100 are mixed, the cooling capacity can be made lower than cooling capacity at the time of immersed cooling. Also, the cooling capacity can be changed optionally by controlling the air blow-in quantity by a controller provided on the way of a compressed air feed pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves passing a steel plate into a water tank and continuously quenching it.
This invention relates to an improvement in continuous hardening equipment for steel sheets.

Conventionally, pressurized cooling water is injected from a nozzle and collides with the surface of the steel plate being conveyed to obtain a high contact speed rtt between the surface of the steel plate and the cooling water, thereby cooling the steel at high speed and performing the quenching process. Nine devices are known to efficiently perform this process.

However, when using this cooling device 'V-, the equipment for making the cooling water high-pressure is large and the amount of cooling water used becomes enormous, resulting in problems such as the quenching equipment becoming expensive and the operating costs increasing. be. Furthermore, as the water supply piping becomes thicker, the space occupied by the piping becomes larger, and the height and length of the quenching equipment need to be increased.In addition, the weight of the piping and its interior increases, making it necessary to reinforce the frame, etc. There is a need to.

In addition, the pitch between the parallel pipes becomes large, making it difficult to increase the jet water flow density, resulting in a disadvantage that the cooling capacity is inevitably reduced. Furthermore, the cooling water nozzle is clogged, which causes uneven quenching, and when the cooling water nozzle becomes clogged, the time and cost required to repair it increase.

Therefore, the inventors developed a water storage tank through which the steel plate first passes to be cooled, and an impeller that is installed in the water tank and moves the cooling water in the moving direction of the steel plate or in the opposite direction to the moving direction. In order to overcome the drawbacks of the above-mentioned apparatus, we proposed a continuous hardening apparatus for steel plates (Japanese Patent Application No. 55-167102, hereinafter referred to as the "prior application").

The continuous steel plate quenching device of this prior application allows for extremely effective contact between the cooling water and the steel plate to be quenched due to the rotation of the impeller installed in the water storage tank, making it possible to perform rapid and uniform quenching work. is possible.

However, in the quenching apparatus of this prior application, there is an improvement problem in that the water tank must always be filled with cooling water during the hardening operation, and the range of adjustment of the cooling capacity is limited. That is, as long as the water storage tank is filled with cooling water, the cooling capacity of the quenching device must be equal to or higher than that of so-called immersion cooling, and it cannot be lower than that. If you try to forcibly lower the cooling capacity and perform quenching without filling the water tank with cooling water, the cooling conditions on the upper and lower surfaces of the steel plate to be quenched will be different, causing uneven cooling or distortion of the steel plate. It is clear that this causes extremely serious problems in terms of quality and operation.

The present invention has been made in view of the current state of the prior art device, and is an extremely effective steel plate that can adjust the cooling capacity over a wide range by simple means. The purpose is to provide a continuous hardening device.

In order to achieve all of these objects, the present invention provides a water tank through which a steel plate passes for cooling, and a water tank provided in the water tank.
In a continuous steel plate quenching apparatus having an impeller for moving cooling water near the surface of a steel plate to be quenched in the direction of movement of the steel plate or the direction of movement of the steel plate, a means for blowing gas into the O cooling water in the water storage tank to generate bubbles; A control means for controlling the amount of gas blown is provided.

The present invention will be described in detail below with reference to the drawings.

Figure 11 is a longitudinal sectional view of a continuous steel plate hardening apparatus according to an embodiment of the present invention. In Figure 1, 10 water tanks, 16
．． Reference numeral 18 denotes rollers that sandwich and transport the steel plate 12 to be hardened. Cooling water 42 is supplied to this water storage tank 10 via main water supply pipes 64, 66 and water supply branch pipes 60, 62. 32. 34 is an impeller, and by this rotation, the cooling water 42 is moved in the moving direction of the steel plate 12 or in the opposite direction.
Effective and uniform hardening can be achieved by effectively utilizing the relative speed of 2 [1]. 1+ On the outside of this water tank 10, water supply pipes 74 are arranged above and below the steel plate 12, corresponding to the openings 14 which are the entrances and exits of the steel plate 12. These water supply pipes 74 are parallel to the main water supply pipes 64 and 66, and are connected to slit nozzles 76. Pressure water 78 is supplied to this slit nozzle 76 from a water supply source, not shown.

The pressure water 78 is ejected toward the opening 14 and
4 to prevent the cooling water 42 in the water storage tank 10 from flowing out.

The apparatus of this embodiment further includes a means for blowing gas (air in this embodiment) into the cooling water 42 in the water storage tank 10, that is, a compressed air supply main pipe 90.92 and this compressed air supply. Main pipe 90.92 and impeller box 56
, 58 are provided, and a control device (not shown) for controlling the amount of air blown from the air blowing means is provided.

Such an air blowing backfilling amount control device is configured to increase or decrease the amount of compressed air depending on the required amount of bubbles, for example, and is configured to increase or decrease the amount of compressed air depending on the required amount of bubbles. Provided with nine air valves etc.
Various devices can be employed.

The operating tube of this embodiment will be described below with reference to FIG. 1 and FIG. 2, which is an enlarged view of part O11 of FIG. 1.

As shown, compressed air is blown into the impeller boxes 5@, 58 through compressed air supply branch pipes 94, 96. This blown compressed air becomes bubbles 100, and the impeller 32,
34 rotations to uniformly mix with the cooling water. In this way, the cooling water 42 containing the bubbles 100 flows to the impeller 32,
The steel plate 12 is cooled as the steel plate 120 moves in the direction of travel or in the opposite direction as it rotates 340 degrees, but the presence of air bubbles 100 causes the cooling capacity to be reduced by immersion cooling. It can be made even lower than the capacity. This is due to the mixture of air bubbles, the cooling water 42 itself and the treated steel plate 1.
This is because the contact area with the steel plate 12 is reduced, and the amount of heat transferred from the steel plate 12 to the cooling water 42 is reduced.

In addition, in the device of the present invention, an air blowing amount control device (not shown) provided in the middle of the compressed air supply piping allows
By adjusting the amount of supplied air, the impeller box 56
．． It is possible to control the amount of air bubbles mixed in the O cooling water in the 58, thereby making it possible to arbitrarily change the cooling capacity.

In the above embodiment, air is used as the gas blown into the water storage tank 10, but other gases may also be used as long as they can generate bubbles in the cooling water.

Figure 3 is a graph showing an example of cooling capacity control in the apparatus of the above embodiment. Figure 3 shows that the test was carried out under the conditions of a steel plate thickness of 30 mm and a supply air pressure of 2/-. Cooling capacity can be adjusted effectively and over a wide range.

As is clear from the above explanation, according to the continuous steel sheet hardening apparatus of the present invention, the cooling capacity can be controlled in a lower cooling capacity range than that of immersion cooling, and the cooling capacity can be specified in the company emblem according to the type of steel to be processed or the size of the steel plate. Can be adjusted. Therefore, it is possible to improve the miner or processing efficiency of processed steel types and to improve the quality of processed steel plates.

Furthermore, as with the prior application device, the conventional nozzle that requires cooling is not required, and accidents caused by nozzle clogging υ can be eliminated. It does not require cooling the entire length of the steel plate at the same time, allowing efficient cooling, making the quenching equipment more compact, and has the excellent features of reducing the amount of cooling water used. .

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of a continuous steel sheet hardening apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged view of the main part of FIG. 1, and FIG.
The figure is a graph showing an example of cooling capacity control. 10・Φ water tank, 32, 34@・impeller. 56.58... Impeller box, 90.92... Main compressed air supply pipe, 94.96... Compressed air supply branch pipe. Agent Tatsuyuki Unuma (and 2 others) Figure 2 Figure 3

Claims (1)

[Scope of Claims] α) A water tank through which the internal IS plate is cooled, and an impeller installed in the water tank to move the cooling water near the surface of the steel plate to be quenched in the direction of movement of the steel plate or in the direction opposite to the direction of movement of the steel plate. A continuous steel plate quenching apparatus comprising: a means for blowing gas into the cooling water in the water storage tank to generate bubbles; and a control means for controlling the amount of gas blown into the water tank. . (2) The continuous steel plate quenching apparatus according to claim 11, wherein the gas is air.