JPH021213B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an impeller for a continuous steel sheet hardening apparatus that continuously hardens a steel sheet by passing it through a cooling tank.

In order to increase the cooling rate of the steel plate and perform quenching work efficiently, it is necessary to increase the relative speed between the surface of the steel plate and the cooling water. For this reason, conventionally, a cooling means has been employed in which pressurized cooling water is injected from a nozzle and collides with the surface of the steel plate.

However, when this cooling method is used, the equipment for making the cooling water high-pressure is large and the amount of cooling water used is enormous, so the quenching equipment is expensive and the operating costs increase. There is. Furthermore, as the water supply piping becomes thicker, the space occupied by the piping increases, which not only necessitates an increase in the height and length of the quenching equipment, but also increases the weight of the piping and its internal parts, which requires reinforcement of the frame, etc. There is a need.

In addition to this, the pitch of the parallel piping becomes large, making it difficult to increase the jet water flow density, and the cooling capacity must be reduced. Also,
Clogging of the cooling water nozzle causes uneven quenching, which has the drawback of increasing the time and cost required to repair the clogging.

In contrast, the present inventors previously proposed a water tank through which a steel plate passes to be cooled, and an impeller installed in the water tank to move cooling water in the direction of movement of the steel plate or in the opposite direction to the direction of movement of the steel plate. He invented and put into practical use a "continuous steel plate quenching device with a wheel".

The present inventor relates to an improvement of such a continuous steel plate hardening apparatus, and in particular, the present inventor aims to make it possible to cool steel plates in a low cooling capacity range, which was considered impossible with conventional apparatuses.

As shown in FIGS. 1 to 3, the steel plate continuous quenching apparatus includes rollers 1 for holding a steel plate 12 from above and below in a water tank 10 and transporting it in the direction of arrow C.
6, 18, and the rollers 16, 18
are configured to be rotated in the directions of arrows A and B by drive devices 28 and 30, and cooling water 42 supplied from main water supply pipes 64 and 66 is provided in the water storage tank 10.
is filled with. Further, the rollers 16,1
Between 8 and 8 are impellers 32 and 3 having blade plates 40.
4 is provided, and the impellers 32, 34 are driven by a drive device 5.
2 and 54 to rotate in the directions of arrows D and E, thereby stirring the cooling water 42. Note that reference numerals 56 and 58 are impeller boxes for efficiently stirring.

The continuous steel plate quenching apparatus moves the cooling water 42 supplied into the water storage tank 10 in the steel plate moving direction or in the opposite direction to the moving direction by rotation of the impellers 32 and 34, and thereby creates front and back surfaces of the steel plate 12 to be quenched. It is characterized by effective and uniform hardening work by effectively utilizing the relative speed of cooling water.
For this reason, this continuous steel sheet hardening equipment is extremely effective for strong cooling for the purpose of hardening, but the surface heat transfer coefficient is 3000 Kcal/m ² hre (800 to 500°C average).
It is not suitable for controlled cooling which requires adjustment of the cooling capacity over a wide range. That is, in the steel plate continuous quenching apparatus, cooling is performed by always filling the water storage tank 10 with cooling water 42, so even if the rotation of the impellers 32 and 34 is stopped and the steel plate 12 is passed through, so-called immersion cooling is performed. However, there is a problem in that a cooling effect equivalent to that of the conventional method can be obtained, but cooling cannot be performed in the required low cooling capacity range.

The present invention takes into consideration the problems of such conventional hardening equipment, and aims to improve the continuous steel plate hardening equipment so that it can not only perform intense cooling for the purpose of hardening, but also perform controlled cooling. In order to achieve this, the rotating shaft of the impeller installed in the water tank is characterized by a two-fluid injection nozzle header that injects a mixed flow of water and air onto the steel plate to cool it.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a front view with a main part cut away showing an embodiment of the impeller of the continuous steel sheet hardening apparatus according to the present invention, and FIG. 5 is a sectional view taken along the line V--V in FIG. 4. Impeller 32', 3 having multiple blade plates 40
4' is pivotally supported by pivot devices 44' and 46' which are fixed to both sides of the water tank (not shown). Further, the rotation shafts of these impellers 32' and 34' form an air header 101 that communicates at one end with an air supply pipe 106 that supplies compressed air via a rotary joint 100 and is closed at the other end. , one end of the air header 101 is connected to a drive device (not shown) via joints 48 and 50. Furthermore, inside the air header 101, which serves as the impeller rotation axis,
A cooling water header 102 is accommodated, one end of which communicates with a cooling water supply pipe 107 via a rotary joint 100, and the other end of which is closed. Further, a two-fluid nozzle header 103 composed of the air header 101 and the cooling water header 102 is attached to the two-fluid nozzle header 103 by penetrating each of these headers 101 and 102, and having one end communicated with the cooling water header 102 and the other. A number of injection pipes 104 are provided whose ends protrude outside the air header 101, thereby ejecting a mixed flow of water and air toward the steel plate to be cooled.

In the middle of each of these injection tubes 104, air introduction holes 105 are provided, each having an axis perpendicular to the axis of the injection tube and communicating with the air header 101.

In the continuous steel plate hardening apparatus using the impellers 32' and 34' of the present invention, which can also be used as a two-fluid injection nozzle header configured in this way, when performing strong cooling for the purpose of hardening, 1
As shown in the figure, the water storage tank 10 is filled with cooling water, and the impellers 32' and 34' are rotated to supply the cooling water to the steel plate 12.
A predetermined quenching operation can be performed by moving in the direction of movement or in the direction opposite to the direction of movement. However, at this time, the two-fluid nozzle header 103
The supply of cooling water and compressed air to the area has been stopped.

On the other hand, when performing controlled cooling using the steel plate continuous quenching apparatus, the supply of cooling water to the water tank is stopped, the cooling water in the water tank is discharged, and the impellers 32' and 34' are The mixed flow ejected from the pipe 104 is stopped at a predetermined position in the direction in which it is effectively injected onto the front and back surfaces of the steel plate to be cooled, and the cooling water header 10
2. Cooling water supply pipe 107 to air header 101
The steel plate 12 is cooled with an arbitrary cooling capacity by supplying cooling water from the rotary joint 100 and compressed air from the air supply pipe 106 and adjusting a cooling water flow rate adjustment device (not shown). At this time, the flow rate of compressed air supplied to the air header 101 is always kept constant at a preset flow rate by a constant flow device (not shown).

As is clear from the above explanation, the steel plate continuous quenching apparatus having an impeller according to the present invention can perform not only strong cooling for the purpose of quenching, but also controlled cooling that cools by injecting a mixed flow of water and air. This makes it possible to significantly expand the types of steel processed by the continuous steel sheet hardening equipment, and there is no need to install a separate cooling device exclusively for controlled cooling, which reduces product costs and provides superior quality. It has become possible to efficiently produce heat-treated steel sheets with low cost and high efficiency.

[Brief explanation of drawings]

Figure 1 is a sectional view of a conventional continuous steel plate hardening apparatus equipped with an impeller, Figure 2 is a sectional view taken along the line - - of Figure 1, Figure 3 is a sectional view taken along the line - - of Figure 1, and Figure 4 is the main FIG. 5 is a front view with a main part cut away showing an embodiment of the impeller of the continuous steel sheet hardening apparatus according to the invention, and FIG. 5 is a sectional view taken along the line - - in FIG. 4. 10... Water tank, 12... Steel plate, 32', 3
4'... Impeller, 100... Rotating joint, 106...
...Air supply piping, 107...Cooling water supply piping.

Claims (1)

[Claims] 1. A water storage tank through which a steel plate passes to be cooled;
In a continuous steel plate quenching apparatus having an impeller installed in the water storage tank and configured to move cooling water in the direction of movement of the steel plate or in the opposite direction to the direction of movement of the steel plate, the rotating shaft of the impeller is used to simultaneously inject water and air. The header is a two-fluid injection nozzle header, and a cooling water supply pipe and a compressed air pipe, which are supplied from a pipe different from the pipe that supplies cooling water to the water storage tank, are connected to the header via a connecting means. Impeller for continuous steel sheet hardening equipment. 2. An impeller for a continuous steel sheet hardening apparatus according to claim 1, wherein a rotary joint is employed as the connecting means.