JPH07233933A - Slurry density regulation equipment - Google Patents

Abstract

PURPOSE:To make the density of slurry be within a desired range by regulating the amount of addition by enlarging the opening of a control valve when a difference between air pressures in two detecting tubes being inserted into a slurry tank and made to differ in the height of the lower end is larger than a set value. CONSTITUTION:There is a difference in a height H between the lower end 13 of a detecting tube 11 and the lower end 14 of a detecting tube 14, both of the tubes being inserted vertically into slurry 10 in a slurry tank 2, and small air discharge holes of the same size are bored in the lower ends 13 and 14 respectively. Air pressure lead-out tubes 16 and 17 are connected to the detecting tubes 11 and 12 respectively and air pressures in the detecting tubes 11 and 12 are led thereby to a differential pressure gage 18. In the case when a differential pressure detected by the differential pressure gage 18 is larger than a set value 20 inputted to a control device 19, the opening of a control valve 7 is enlarged, and when the differential pressure detected by the differential pressure gage 18 is smaller than the set value 20, the opening of the control valve 7 is lessened. Thereby the quantity of addition liquid to be supplied to a mixer 1 is regulated and the density of the slurry entering the slurry tank 2 is thereby regulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slurry concentration adjusting device capable of measuring the concentration of slurry during transportation and adjusting the concentration of the slurry to a required concentration.

[0002]

2. Description of the Related Art When a slurry is conveyed, for example, when coal is pulverized or pulverized into a slurry and the slurry is supplied to a boiler as a fuel, if the slurry concentration is too low (thin), solid matter precipitates. If the slurry concentration is too high (dark), it becomes too viscous to be transported. Further, there is a range of slurry concentration suitable as a fuel even in the boiler to which it is transported.

As described above, the slurry is required to have a desired concentration depending on the type of solid material and the purpose of use.

For this reason, conventionally, the slurry being conveyed was appropriately sampled, its concentration was measured, and the amount of the additive liquid was adjusted to bring the slurry concentration into a desired range.

[0005]

In the conventional method in which the slurry is appropriately sampled and the concentration is measured and the amount of the added liquid is adjusted depending on the concentration, the measurement is troublesome and time-consuming. There was a drawback that it could not respond appropriately to changes in the concentration of the slurry inside.

The present invention eliminates such conventional drawbacks,
An object of the present invention is to provide a slurry concentration adjusting device that continuously measures the concentration change of slurry during transportation and automatically adjusts the amount of the added liquid according to the measured value so that the slurry concentration falls within a desired range. It is what

[0007]

SUMMARY OF THE INVENTION A slurry concentration adjusting device of the present invention supplies a liquid mixture to a mixer and a slurry tank connected to a slurry conveying path, and a control valve to the mixer. The additive liquid supply pipe, two detection pipes which have air discharge holes at the lower ends and are inserted into the slurry tank with different heights at the lower ends, and a constant pressure at the upper ends of the two detection pipes, respectively. An air supply source that supplies air, a differential pressure gauge that detects a differential pressure between air pressures in the two detection pipes, and if the differential pressure detected by the differential pressure gauge is larger than a set value, the opening degree of the control valve is changed. And a control device for increasing the opening of the control valve when the differential pressure detected by the differential pressure gauge is smaller than a set value.

[0008]

When the slurry being conveyed enters the slurry tank, the pressure difference with respect to the height difference between the lower ends of the two detection tubes is detected by the differential pressure gauge, and the specific gravity of the slurry is measured by the controller by the pressure difference, and the concentration is measured. Is required. The opening of the control valve is controlled according to the measured value, the amount of the additive liquid supplied to the mixer is adjusted, and the slurry concentration is maintained in a desired range.

[0009]

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

FIG. 1 is a system diagram of an embodiment of the present invention, in which a mixer 1, a slurry tank 2 and a slurry pump 3 are sequentially connected and provided in a slurry conveying path.
The slurry supplied from the slurry supply pipe 4 to the mixer 1 is put into the slurry tank 2 from the mixer 1 and then sent to the slurry delivery pipe 5 by the slurry pump 3 to be conveyed to the intended place. ing.

To the mixer 1, an additive liquid such as water is supplied from an additive liquid supply pipe 6 through a control valve 7. In the mixer 1, the slurry supplied from the slurry supply pipe 4 The additive liquid supplied from the additive liquid supply pipe 6 is mixed and then sent to the slurry tank 2.

A stirring blade 9 rotated by a motor 8 is provided in the slurry tank 2 so as to stir the slurry 10 in the slurry tank 2 to obtain a uniform slurry concentration.

In the slurry 10 of the slurry tank 2, two detection tubes 11 and 12 are vertically inserted. The two detection tubes 11 and 12 have the same inner diameter, but the lower end 13 of the detection tube 11 is shallowly inserted into the slurry 10 in the slurry tank 2, and the lower end 14 of the detection tube 12 is the slurry tank 2. It is deeply inserted into the slurry 10 inside, and a difference in height H is provided between the lower end 13 of the detection pipe 11 and the lower end 14 of the detection pipe 12. The lower end 13 of the detection tube 11 and the lower end 14 of the detection tube 12 are provided with small air discharge holes (not shown) of the same size.

The upper ends of the two detection tubes 11 and 12 are connected to an air supply source 15 such as an air supply valve for supplying air of constant pressure, and the air of constant pressure is applied to the upper ends of the detection tubes 11 and 12. Each is supplied. In addition, the detection tubes 11, 1
Air pressure lead-out pipes 16 and 17 are connected to 2 respectively, and the air pressure in the detection pipes 11 and 12 is guided to a differential pressure gauge 18.

The differential pressure gauge 18 has two detection tubes 11 and 12 based on the air pressure in the detection tube 11 guided by the air pressure derivation tube 16 and the air pressure in the detection tube 12 guided by the air pressure derivation tube 17. The differential pressure of the air pressure is detected, and the detected differential pressure is input to the control device 19 composed of a computer.

The control device 19 controls the opening of a control valve 7 provided in the middle of the additive liquid supply pipe 6, and controls the differential pressure detected by a differential pressure gauge 18 as described later. When the set value 20 input to the device 19 is larger than the set value 20, the opening degree of the control valve 7 is increased, and when the differential pressure detected by the differential pressure gauge 18 is smaller than the set value 20, the open degree of the control valve 7 is decreased. It has a control function to operate.

Next, the operation of the apparatus shown in FIG. 1 will be described.

Slurry such as coarsely or finely pulverized coal which is to be supplied to the boiler as fuel is supplied from the slurry supply pipe 4 to the mixer 1, and in the mixer 1, the additive liquid supply pipe 6 to the control valve 7 is supplied. After being mixed with an additive liquid such as water supplied through the tank, it is temporarily stored in the slurry tank 2 and stirred by the stirring blade 9 so as to obtain a uniform slurry concentration.

From the air supply source 15, two detection tubes 11, 1 are provided.
Air of a constant pressure is supplied to the upper end of 2, and the detection tubes 11, 1
The air supplied to 2 passes through the inside of the detection tubes 11 and 12, respectively, and is discharged into the slurry 10 in the slurry tank 2 from a small air discharge hole (not shown) of the same size which is formed in the lower ends 13 and 14. To do.

In this case, the external pressure of the slurry 10 acting on the lower end 13 of the detection pipe 11 at the shallow position in the slurry 10 is small, but the slurry 10 acting on the lower end 14 of the detection pipe 12 at the deep position in the slurry 10 is small. The external pressure is high. Therefore, even if the same constant pressure air is supplied to the upper ends of the two detection tubes 11 and 12, the lower end 1
Since air is easily discharged from the lower end 13 of the detection tube 11 where a small external pressure acts on 3, the air pressure inside the detection tube 11 becomes a low pressure considerably lower than the constant pressure, and 6 large external pressure acts on the lower end 14. Lower end 1 of detecting tube 12
Since air is difficult to be discharged from No. 4, the air pressure in the detection tube 12 is maintained at a high pressure that is slightly lower than the constant pressure. The differential pressure of the air pressure in the detection pipes 11 and 12 is detected by the differential pressure gauge 18 and input to the control device 19.

From the differential pressure ΔP of the air pressure in the detection tubes 11 and 12 and the height H of the difference between the lower ends 13 and 14 of the detection tubes 11 and 12, the specific gravity γ of the slurry 10 in the slurry tank 2 is obtained.
Is

It can be calculated by γ = ΔP / H.

The concentration of the slurry 10 and the specific gravity γ of the slurry 10 have a constant relationship as shown in the graph of FIG. 2. When the specific gravity γ of the slurry 10 is large, the concentration of the slurry 10 is high. When the specific gravity γ of the slurry 10 is small, the concentration of the slurry 10 is low.

The relationship between the slurry concentration and the specific gravity of the slurry as shown in the graph of FIG. 2 and the desired range of the slurry concentration are input as the set value 20 to the control device 19 in advance. Two detection tubes 1 detected by the pressure gauge 18
Slurry 1 in slurry tank 2 from differential pressure ΔP in 1, 12
A concentration of 0 is calculated.

When the differential pressure ΔP of the air pressures in the detection pipes 11 and 12 exceeds a certain range, it is judged that the concentration of the slurry 10 is too thicker than the set value 20 (desired range). The opening of the control valve 7 to increase the mixer 1
The amount of the additive liquid supplied to is increased so that the concentration of the slurry 10 entering the slurry tank 2 becomes thin.

On the contrary, when the differential pressure ΔP of the air pressures in the detection tubes 11 and 12 is less than a certain range, the slurry 10 is used.
It is judged that the concentration of is too thin than the set value 20 (desired range), the opening of the control valve 7 is reduced, the amount of the additive liquid supplied to the mixer 1 is reduced, and the slurry tank 2 is reduced. The concentration of the slurry 10 that enters is thickened.

As a result, the concentration of the slurry 10 agitated in the slurry tank 2 is constantly measured, and when the concentration is higher than the desired range, the amount of the additive liquid supplied to the mixer 1 increases. , The concentration of the slurry 10 entering the slurry tank 2 becomes thin, and when the concentration is too thin than the desired range, the amount of the additive liquid supplied to the mixer 1 becomes small and the concentration of the slurry 10 entering the slurry tank 2 becomes small. Becomes thicker and the concentration of the slurry 10 entering the slurry tank 2 is adjusted to be maintained in a desired range.

The slurry 10 stirred in the slurry tank 2
Is delivered to the slurry delivery pipe 5 by the slurry pump 3,
Transported to the intended place.

[0028]

According to the present invention, the slurry concentration in the slurry tank is constantly measured, and when the measured slurry concentration is higher than the desired range, the amount of the additive liquid supplied to the mixer is increased to increase the slurry tank. The concentration of the slurry entering the slurry tank is reduced, and when the slurry concentration is too thin than the desired range, the amount of the additive liquid supplied to the mixer is reduced to increase the concentration of the slurry entering the slurry tank and then entering the slurry tank. There is an effect that the concentration of the slurry is adjusted so as to be kept in a desired range and the slurry kept in the concentration of the desired range can be continuously supplied.

[Brief description of drawings]

FIG. 1 is a system diagram of an embodiment of the present invention.

FIG. 2 is a graph showing an example of the relationship between slurry concentration and specific gravity.

[Explanation of symbols]

 1 Mixer 2 Slurry tank 6 Additive liquid supply pipe 7 Control valve 11 Detection pipe 12 Detection pipe 13 Lower end 14 Lower end 15 Air supply source 18 Differential pressure gauge 19 Control device 20 Set value H Height

Claims (1)

[Claims] 1. A mixer and a slurry tank connected to a slurry conveying path, an additive liquid supply pipe for supplying an additive liquid to the mixer via a control valve, and an air discharge hole at a lower end. Then, the two detection tubes inserted into the slurry tank with different heights at the lower ends, the air supply sources for supplying air of constant pressure to the upper ends of the two detection tubes, and the two detection tubes A differential pressure gauge for detecting the differential pressure of the air pressure in the detection pipe, and when the differential pressure detected by the differential pressure gauge is larger than a set value, the opening of the control valve is increased so that the differential pressure detected by the differential pressure gauge is lower than the set value. And a controller for reducing the opening of the control valve if the opening is small.