JPH0274544A - Method for controlling amount of cooling water in granulated slag production and apparatus therefor - Google Patents

Abstract

PURPOSE:To improve the quality of granulated slag by measuring the weight and volume of the granulated slag slurry in a draining tank to calculate the amount of the slag according to a specific equation and control the amount and pressure of cooling water for the slag. CONSTITUTION:Pressurized water is jetted to the slag and the resultant slag slurry is transferred from the agitation tank 13 to the draining tank 20 where the weight W of the slag slurry is measured with the load cell 22, and the volume V is measured with the level meter 21 to calculate the weight of the slag flowing in the draining tank according to the equation (where gammas is specific gravity of the slag, gammaw is the gravity of water in the draining tank). The arithmetic unit 11 calculate the volume of cooling water so that the distribution ratio of the slag to the cooling water becomes a prescribed set value. The controller 12 controls the flow rate control valve 3 and the pressure-controlling device 1 according to the arithmetic results, and the signals of the flow meter 2 and the pressure meter 4 for the cooling water. Thus, the quality of the slag is stabilized and the power cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a method and apparatus for controlling the amount of cooling water during the production of granulated slag.

[Prior Art] In order to improve the quality of granulated water, it is necessary to constantly increase the amount of slag and control the amount of cooling water in accordance with the fluctuating amount of slag.

The amount of slag can be measured by directly measuring the amount of molten slag, by measuring the load on the continuous dewatering device and calculating it, and by installing a load cell on the conveyor for transporting the slag or slag after dewatering. Various methods have been proposed for measuring this.

For example, in Japanese Patent Application Laid-Open No. 56-26752, a dewatering device is provided with a weight measuring device for measuring the weight of granulated water, and an unloading conveyor is provided with a flow rate measuring device for measuring the flow rate of granulated water.
The flow rate of slag flowing out of the furnace is calculated from these measured values.

A device for controlling the amount of cooling water during the production of granulated slag is disclosed in, for example, Japanese Patent Application Laid-Open No. 61-270238, and as a device for suitably implementing this method, each blown box is divided into a plurality of parts and the amount of cooling water is adjusted individually. What about the nozzle plate installed in each blown box? I
By dividing the cooling water pump into several parts, providing a water flow control valve in each divided part, and keeping the total opening area of the injection holes provided in all the divided parts constant at all times, the pressure of the cooling water pump and the total water supply volume can be maintained at all times. Therefore, the operation of the cooling water pump is stable, and the amount of water supplied to each blown box is controlled appropriately by opening or closing each control valve depending on the amount of molten blast furnace slag. The aim was to maintain a fair distribution ratio.

[Problem to be Solved by the Invention 1 Regarding the method of controlling the amount of cooling water, in the conventional technology, the amount of granulated slag is affected by the water content, and as a result, it is still not suitable for industrial use due to poor measurement accuracy. Currently, there is no technical means available for this purpose, and therefore, there is currently no method for controlling the amount of cooling water appropriately in response to the fluctuating amount of slag.

In addition, cooling water placement (as for the device, please refer to the above-mentioned Japanese Unexamined Patent Publication No. 61-2
No. 70238 had the following problems. That is, (1) the distribution ratio of the supply water l of the cooling water changes in response to the change in the amount of molten blast furnace slag;

■As the injection holes provided in each nozzle plate wear out, the amount of water and water pressure fluctuate accordingly.

■Due to the above reasons, the granulation cooling conditions of granulated slag change and the product quality fluctuates.

■Multi-stage blown boxes make the equipment larger and are less economical and maintainable.

■Production costs increase because the distribution ratio of slag and water is higher than necessary.

The present invention was proposed in order to solve the above-mentioned problems, and by accurately determining the granulated slag amount without being affected by the water content and understanding the amount of granulated slag, it is possible to obtain more fine-grained slag. A method for controlling the amount of cooling water that enables fine control of the amount of slag, and a method that immediately responds to fluctuations in the amount of slag and controls the distribution ratio of slag and cooling water and blowing pressure to remain constant, thereby improving product quality. An object of the present invention is to provide a cooling water amount control device for granulated slag, which stabilizes the flow rate of granulated slag.

[Means for Solving the Problems J] The present invention provides a method for controlling the amount of cooling water when producing granulated slag by injecting cooling water into slag to produce granulated slag slurry and dewatering the slurry in a square dehydration tank. The method and control device adopted the following technical measures. That is, in the method of the present invention, if the weight and volume of granulated slag are measured and calculated in a dehydration tank in a slurry state, the amount of granulated slag can be accurately measured without being affected by the water content. Based on the knowledge, the dehydration tank is equipped with a weight measuring device to measure the weight of the granulated slag slurry in the dehydration tank, and a volume measuring device is installed to measure the volume of the granulated slag slurry, and based on these measured values, This method calculates the amount of slag flowing into the dehydration tank using the following formula, and controls the amount of cooling water and the cooling water injection pressure for the slag according to the amount of slag.

ws=γs (W ywV)/ (ys yw)
however.

Ws: Weight of granulated slag W: Weight of granulated slag slurry in the dehydration tank V: Volume of granulated slag slurry in the dehydration tank γs: Specific gravity of granulated slag γW: Specific gravity of water in the dehydration tank.

The device of the present invention includes: (1) a calculation device that calculates the cooling water flow rate so that the distribution ratio of slag and cooling water and the blowing pressure become predetermined set values in response to the fluctuating amount of slag output, and (2) a /iil calculation device. The blowing pressure regulating device is equipped with a control device that controls the cooling water flow rate adjustment valve and the blowing pressure regulating device, respectively, from the hanging device number, the signal from the cooling water flow meter, and the signal from the blowing pressure gauge. It fits into a plurality of wedge-shaped regulating valve bodies and the regulating valve body. A nozzle plate with a jet hole,
It consists of a control valve body driver that adjusts the gap between the control valve body and the jet hole to adjust the blowing pressure.

[Effect 1 (1) In the method of the present invention, the weight W of the granulated slag slurry in the dehydration tank, the volume V of the granulated slag slurry in the dehydration tank
The reason why the ffi i W s of the granulated slag is determined from the specific gravity γs of the granulated slag and the specific gravity γ1 of the water in the dehydration tank is explained below.The weight ff1W of the granulated slag slurry in the dehydration tank is It is expressed as the sum of ffE m W s and the tonne of water 4h. That is, W=Ww+Ws Here, since it is expressed as Ww=1'w (V-WS/Y5), W '' Y w (V W s / Y s ) +
W s=γW V−Y W W 5 / y 5 +
W 5 Therefore, ws-γWws, 'γ5=w-y, v W s (I Y w / y s ) = W
y w VWs=γs (W ywV)/ (Ys
Yw) That is, the weight i W 5 of the granulated slag is obtained.

This ffi monitoring of the granulated slag makes it possible to control the amount of cooling water more precisely (wholesale), so it is possible to improve the quality of the granulated slag.

(2) The operation of the device of the present invention will be explained. Although the amount of slag (sludge output rate) varies in the range of 1-10 ton/min, the distribution ratio of cooling water and slag needs to be 4-10 from the viewpoint of product quality, manufacturing cost, and safety measures. Since the present invention is configured as described above, even if the amount of slag produced changes, it is possible to immediately respond to the change and control the flow rate control valve of the cooling water and the control valve body of the blowing pressure control device. The cooling water distribution ratio and blowing pressure can be maintained constant. In addition, there is no change in the amount or pressure of cooling water due to wear of the control valve body and jet holes.

Therefore, it is possible to stabilize product quality and reduce operating costs of the cooling water pump.

[Example 1] Fig. 1 shows a cooling water fine control device and a cooling water system diagram for producing granulated slag according to the present invention. FIG. 3 is a sectional view taken along line AA in FIG. 2.

As shown in FIG. 1, pressurized water is injected into the molten slag that has flowed into the blown box to make granulated slag slurry, and the granulated slag slurry is transferred from the stirring tank 13 to the dehydration tank 2 by the granulation pump 14.
0. This dehydration tank 20 is equipped with a dewatering screen 24 at the bottom of the tank, and performs so-called gravity dehydration in which the granulated slag is allowed to settle and dehydrated using the filtration action of the granulated slag.

The water flowing out from the overflow pipe 16 or the dehydration pipe 15 is stored in the hot water Pa 17, and after removing the fine slag contained in this water, it is sent to the cooling tower 18 by a pump, where it is cooled and transferred to the cold water tank 19. is stored. This water is supplied to the cooling water piping 6 by the cooling water pump 7 and is configured to be circulated again as pressure water.

FIG. 1 shows a state in which granulated slag 23 in the granulated slag slurry has settled in the lower part of the dehydration tank 20. ffi ffi W of the granulated slag slurry in the dewatering tank 20
can be measured by a load cell 22 provided in the dehydration tank 20. At this time, by injecting water into the dehydration tank 20 in advance, the load cell 22 can be calibrated with high accuracy, so that the measurement by the load cell 22 can be performed accurately.

Further, the volume V of the granulated slag slurry can be accurately measured by a water level gauge 21 provided in the dehydration tank 20.

The specific gravity γs of the granulated slag approximates the true specific gravity since it is in water, and the specific gravity γ1 of water in the dehydration tank can be easily determined by measuring its temperature.

If ff1lWs of granulated slag is measured over time, the production amount and production rate (slag output rate t, on/mi
n) can also be easily reduced to 1!1. Ichikawa W of this granulated slag
The cooling water can be controlled by s.

As shown in FIG. 1, the control device of the present invention includes a flow meter 2 and a flow control valve 3 in the cooling water pipe 6 to which cooling water is supplied from the cooling water pump 7, and a pressure gauge in the blown box. 4 and a pressure regulating valve body 5 are provided. Further, the calculation device 11 calculates the cooling water flow rate so that the distribution ratio of the slag to the cooling water becomes a predetermined set value in response to the fluctuating amount of slag output.

The control device 12 controls the flow rate regulating valve 3 and the pressure regulating device 1 based on the results of this calculation and the signals from the cooling water flow meter 2 and blowing pressure gauge 4.

In this device, fluctuations in the amount of slag are inputted by the calculation results of the calculation device 11, but it is also possible to automatically detect and input changes in the amount of molten slag, the water temperature in the stirring tank, etc. Practically speaking, there is no problem in manually calculating the visual measurement results.

As shown in FIG. 2, the pressure regulator l has two sets of P! The nozzle plate 10 includes a shaped regulating valve body 5, a nozzle plate 10 provided with an ejection hole 9 that fits into the regulating valve body 5, and a regulating valve body driving machine 8 that drives the regulating valve body 5 and adjusts the blowing pressure. There is. The regulating valve body driver 8 is controlled by a control device I2 shown in FIG. 1 to regulate the blowing pressure.

FIG. 4 is a graph showing the results of implementing the present invention. This shows the relationship between the slag removal time and the water supply amount when three cooling water pumps 7 are used and the distribution ratio is 5. In the conventional example, the amount of slag produced could not be accurately assessed, so the amount of water supplied was increased early to be safe. According to the present invention, the amount of water supplied can be increased just before the distribution ratio becomes 5 or less, so the amount of water used can be reduced and the power cost can be reduced. In addition, the nozzle of the blown box does not need to be multi-staged; instead, it is sufficient to use only one nozzle, and the scale of the equipment can be reduced.

〔Effect of the invention] The present invention has the following extremely excellent effects.

■It is possible to significantly improve the control technology of metallurgical furnace slag volume management and metallurgical furnace control technology, which can contribute to improved productivity.

■Since it is possible to keep the cooling water distribution ratio and blowing pressure constant according to the amount of molten slag, product quality can be stabilized and power costs can be reduced.

■Since the cooling water distribution ratio and blowing pressure can be set arbitrarily, granulated slag with different properties can be easily produced.

■It is possible to reduce the scale of the equipment by using one stage of blown box nozzles.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of the cooling water amount control device and cooling water of the present invention, FIG. 2 is an explanatory diagram of an embodiment of the pressure regulating device of the present invention, and FIG. 3 is a sectional view taken along line A-A in FIG. FIG. 4 is a graph showing the results of implementing the present invention. ! ...-Pressure regulator 2...Flow meter 3--Flow rate control valve 4--Pressure gauge 5...Control valve body 6--Cooling water piping 7...Pump 8...Control valve body drive Machine 9...Blowout hole 10...Nozzle plate 11...Arithmetic device 12...-Control device 20...Dehydration tank 21...Water level gauge 22-...Load cell 23...Granulated slag 24 ...-Dehydration screen applicant Kawasaki agent Kawatetsu Mining Co., Ltd.

Claims (1)

[Claims] 1. When producing granulated slag by injecting cooling water onto the slag to produce granulated slag slurry and dewatering the slurry in a gravity dehydration tank, A weight measuring device is provided to measure the weight of the granulated slag slurry, and a volume measuring device is provided to measure the volume of the granulated slag slurry. Based on these measured values, the amount of slag flowing into the dehydration tank is calculated by the following formula. A method for controlling the amount of cooling water, characterized in that the amount of cooling water and the injection pressure of the cooling water for the slag are controlled according to the amount of slag. W_s=γ_s(W-γ_wV)/(γ_s-γ_w)
However, Ws: Weight of granulated slag W: Weight of granulated slag slurry in the dehydration tank V: Volume of granulated slag slurry in the dehydration tank γ_s: Specific gravity of granulated slag γ_w: Specific gravity of water in the dehydration tank be. 2. A calculation device that calculates the cooling water flow rate so that the distribution ratio of slag and cooling water and the blowing pressure become predetermined set values in response to the fluctuating amount of slag, and the output signal of the calculation device and the cooling water flow meter. and a control device for controlling a cooling water flow rate regulating valve and a blowing pressure regulator, respectively, based on the signal from the blowing pressure gauge and the blowing pressure gauge, the blowing pressure regulating device comprising a plurality of wedge-shaped regulating valve bodies and a blowing pressure regulating device. , a cooling water amount control device comprising a nozzle plate provided with a jet hole that fits into the regulating valve body, and a regulating valve body driver that adjusts the gap between the regulating valve body and the jet hole to adjust the blowing pressure. .