JPS5853987B2 - Method and device for adjusting the amount of slurry projected by an abrasive material projection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for adjusting the amount of slurry projected by an abrasive material projection device, and more specifically, a slurry consisting of an abrasive material and a liquid is sprayed at high speed with a pressurized liquid onto the surface of a metal strip or the like. Use and project,
This invention relates to adjusting the amount of abrasive slurry sprayed in wet blasting for descaling the surface, surface grinding, etc.

Conventionally, the surface of metal strips has been descaled by pickling, but as pollution regulations and equipment costs and running costs have increased, it has been desired to provide a non-polluting and inexpensive descaling method.

In response, wet blasting has been developed as an inexpensive and non-polluting method, and is now at the stage of practical application.

In the wet blasting method, abrasive particles are mixed and stirred in a liquid (e.g., industrial water) to form a slurry, and the slurry is poured into jet water in which a pressurized liquid (e.g., industrial water) is sprayed at high speed to blast the abrasive particles. The abrasive particles accelerated at high speed are projected onto the metal surface to remove surface scale or grind the metal surface.

When uniformly and continuously treating the surface of metal strips, such as steel strips, even if there are changes in the speed of the steel strip, the surface properties of the continuous steel strips, or other factors, the surface of the continuous steel strips can be uniformly treated. It is necessary to.

The load required for surface treatment of a steel strip is calculated by calculating the amount of collision work of abrasive particles projected onto a unit area of the surface.
1. If the moving speed of the steel strip is ■, L2 is −JE−W・
■ (However, K is a constant).

JE is a value determined by the material and degree of processing, and is determined by the magnitude of kinetic energy of the abrasive particles being projected and the collision environment.

This kinetic energy is determined by the amount of pressure liquid to be jetted, the jetting speed, the amount of abrasive particles, the acceleration environment, etc.

Therefore, in order to treat the surface of the steel strip uniformly or to a desired degree, it is fundamentally important to control the jetting pressure of the pressurized liquid as well as the jetting amount of the abrasive slurry.

The purpose of the present invention is to solve this fundamental problem regarding abrasive slurry.The present invention is aimed at solving this fundamental problem regarding abrasive slurry. In wet blasting, in which material is projected onto the surface of a metal strip to perform descaling, surface grinding, etc., metal The present invention relates to a method and apparatus for adjusting the amount of abrasive slurry projected onto a surface of a strip, which is characterized by adjusting the amount of abrasive slurry projected onto the surface of a strip.

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

The drawings show an example of an apparatus for carrying out the method for adjusting the amount of projected slug IJ of an abrasive material projection apparatus according to the present invention.

This projection slurry amount adjustment device includes a projection nozzle device 3,
A slurry supply tank 1 stores an abrasive slurry 7 and supplies it to the projection nozzle device 3, and also injects a pressurized gas, for example, pressurized air 5, and a slurry supply tank 1 in which the abrasive slurry 7 is prepared and the pressurized air 5 is injected. a slurry preparation tank 2 for intermittently replenishing the slurry supply tank 1 with the abrasive slurry 7;
It is comprised of an automatic pressure control device 4 that adjusts the supply discharge amount (projection slurry amount) of the abrasive slurry 7 supplied to the projection nozzle device 3, and the like.

The slurry supply tank 1 has a slurry tank 1-1 as a main body, and the slurry tank 1-1 has a slurry injection pipe 1-2 and a slurry discharge valve P1, and is connected to the projection nozzle device 3. A slurry discharge pipe 1-3, a pressure air supply pipe 1-4 having an air supply valve DV and an air regulating valve RV1, an air exhaust pipe 1-5 having an air exhaust valve Dv2 and an air regulating valve Rv2
and slurry level detector L1. L2.
L3, slurry pressure detector P1 slurry IJ-mixer M1
It is composed of:

The slurry preparation tank 2 is installed upstream of the slurry supply tank 1, and has a slurry tank 2-1 as its main body. 2. A slurry discharge pipe 2-3 having a slurry discharge valve (replenishment valve) Pv2 and communicating with the slurry injection pipe 1-2 of the slurry supply tank 1, an air supply valve D■3, and an air adjustment valve R■3. Pressure air supply pipe 2-4, air exhaust valve D
Connect the air exhaust pipe 2-5 with L4.v4 and the slurry level detector L4. L5 and slurry mixer M2.

The projection nozzle device 3 is equipped with a projection nozzle (not shown) inside, and jets high-pressure water 8 supplied from a high-pressure water supply device (not shown) at high speed, and also jets high-pressure water 8 from the slurry supply tank 1 at high speed. The supplied abrasive slurry 7 is discharged and mixed with a high-speed jet 9 generated by high-pressure water 8 to form a high-speed abrasive jet 10, which is then projected onto a steel strip S.

The automatic pressure control device 4 controls the discharge of the slurry 7 to be supplied to the projection nozzle device 3 based on the moving speed signal of the steel strip S and the detected pressure signal of the slurry pressure detector P of the slurry supply tank 1. It has a function of adjusting and controlling the supply discharge amount of the slurry 7 by controlling the pressure of the supply pressure air 5 to the slurry supply tank 1 so that the pressure becomes a required value (speed signal of the steel strip S). (includes information regarding the current speed or the speed to be changed in the future).

Next, the operation of adjusting the amount of slurry to be projected in the apparatus configured as described above will be explained.

[Operation A]

As shown in the figure, the slurry preparation tank 2 has a slurry injection valve Pv
3. Open the air exhaust valve DV4 and slurry replenishment valve P■2
, the air supply valve Dv3 is closed, the slurry 7 is injected from the slurry injection pipe 2-2, and the slurry mixer M2 is driven to stir the slurry 7 injected into the slurry preparation tank 2.

In the slurry supply tank 1, the slurry discharge valve PV and the air supply valve Dv1 are opened, and the slurry mixer M1 is driven to supply the slurry 7 to the projection nozzle device 3 while stirring the slurry 7 in the tank (air exhaust Valve Dv2 is closed).

The amount of slurry to be projected is adjusted by controlling the pressure detected by the slurry pressure detector P to a required value.

This slurry pressure is determined by the height Hs of the slurry 7 stored in the slurry supply tank 1 and the air pressure Pa1r in the slurry supply tank 1.

Slurry discharge pressure crab P7α -H3+Pa1r (K is a coefficient) From this, by controlling the pressure of the supply pressure air so that the detected pressure of the slurry pressure detector P becomes the required value, the amount of projected slurry can be adjusted to the required amount. It's being adjusted.

Pa1r is controlled by automatically adjusting the air control valve RV1.

[Operation B]

When the slurry 7 injected into the slurry preparation tank 2 reaches the position of the slurry level detector L4, the injection of the slurry 7 is stopped by a signal from the detector L4, and the slurry injection valve P3 and air exhaust valve DV4 are closed. The system is closed and waits until it is time to replenish slurry supply tank 1 with slurry 7.

At this time, the mixer M2 is driven and the slurry 7 is being stirred.

During this time, the concentration of the slurry 7 may also be adjusted.

[Operation C]

Next, since the slurry supply tank 1 is continuously supplying the slurry 7 to the projection nozzle device 3, the amount of the slurry 7 stored in the slurry supply tank 1 is reduced.
When the slurry level detector L2 detects this and issues a signal, the valve P■2°Dv2. Open D■3 and air control valve RV1. The slurry 7 is replenished from the slurry preparation tank 2 to the slurry supply tank 1 while automatically adjusting RV2°Rv3 to maintain the slurry discharge pressure of the slurry supply tank 1 at a required value.

When the slurry 7 replenished to the slurry supply tank 1 reaches the position of the slurry level detector L1, a signal from the detector L1 causes the valve P2. Dv2°Dv3 is closed, and the valve D■3. Dv4 is opened and slurry 7 is poured into slurry preparation tank 2.

By repeating the above operations A-C, the slurry 7 can be intermittently replenished to the slurry supply tank 1 and continuously supplied to the projection nozzle device 3. Therefore, the amount of projected slurry can be adjusted by adjusting the air pressure Pa1r in the slurry supply tank 1. It can be adjusted by changing.

As described above, the present invention exhibits the following excellent effects.

(1) The amount of abrasive slurry to be projected can be adjusted to the required amount according to the material and surface properties of the material to be blasted (for example, a steel strip) (by controlling the slurry discharge pressure).

(11) The amount of abrasive slurry projected can be adjusted according to the moving speed of the material to be blasted.

For example, when performing surface treatment (descaling, surface grinding, etc.) on a steel strip while moving it at high speed, the strip surface is The required amount of abrasive slurry can be projected onto the surface.

(iii) By combining the injection pressure liquid pressure control and the injection slurry amount adjustment control of the present invention, for example, the descaling of the sl-IJ tube surface can be performed by stripping in response to changes in stripping speed and changes in surface texture. It is also possible to process uniformly in the longitudinal direction.

GV) Wasted wet blasting energy can be eliminated by appropriately controlling the amount of abrasive slurry sprayed. Some of the abrasive material is consumed and the impact force of the abrasive material colliding with the steel strip plate weakens, making it impossible to obtain the desired surface treatment effect.
Also, if the amount of slurry to be projected is small, the speed of the abrasive will become excessively high, resulting in excessive treatment of the steel strip surface.)
.

[Brief explanation of drawings]

The drawing is a block diagram showing one embodiment of the present invention. 1... Slurry supply tank, 2... Slurry preparation tank, 3... Projection nozzle device, 4...
... Automatic pressure control device, 5 ... Pressure air, 7.
... Abrasive slurry 8 ... High pressure water, S
・・・・・・Strip steel plate.

Claims (1)

[Claims] 1. A method of supplying and mixing an abrasive slurry to a high-speed jet liquid injected with a pressurized liquid and accelerating the abrasive material to a required speed onto the surface of a metal strip to descale the surface and In wet blasting for grinding, etc., the amount of abrasive slurry projected onto the metal strip surface is adjusted by controlling the discharge pressure of the abrasive slurry discharged from the abrasive material projection device using pressurized gas. A method for adjusting the amount of slurry projected by an abrasive material projection device. 2. Wet blasting, in which abrasive slurry is supplied and mixed with a high-speed jet liquid injected with pressure liquid, and the abrasive material, which is accelerated to a required speed, is projected onto the surface of a metal strip to descale, grind, etc. the surface. , a slurry supply tank configured to store abrasive slurry and supply it to an abrasive slurry projection device and inject pressurized gas; A projection slurry amount adjustment device for an abrasive material projection device, comprising a pressure control device that adjusts the supply and discharge amount of the slurry by controlling gas pressure. 3. Wet blasting, in which an abrasive slurry is supplied and mixed with a high-speed jet liquid injected with a pressure liquid, and the abrasive material is accelerated to a required speed and projected onto the surface of a metal strip to descale, grind, etc. the surface. , a slurry supply tank configured to store abrasive slurry and supply it to an abrasive slurry projection device and inject pressurized gas; A pressure control device that adjusts the supply and discharge amount of the slurry by controlling the gas pressure, and a pressure control device that is disposed upstream of the slurry supply tank and that prepares the abrasive slurry and injects pressurized gas to make the abrasive slurry. A projection slurry amount adjusting device for an abrasive material projection device, comprising a slurry preparation tank that intermittently supplies slurry to the slurry supply tank.・