JPS5835610A - Concentration controlling method - Google Patents

Abstract

PURPOSE:To obtain a liquid having a very high-precision concentration, by calculating and controlling the concentration of a material to be mixed in a mixing liquid on a basis of the density of each material to be mixed and the density of the mixing liquid before mixing. CONSTITUTION:When a set value is given to a supply quantity controller 12c for heavy oil, the flow rate of heavy oil is read from a flowmeter 12b to calculate the quantity of heavy oil which is supplied actually and is compared with the new set value, and such command signal is issued that the opening of a flow rate control valve 12a is controlled to cancel the difference. When a set value is given to a supply quantity controller 21d for coal, the weight of coal is read from a weight meter 21b to calculate the quantity of coal which is supplied actually, and this quantity is compared with the new set value, and such command signal is issued that the motor 21c controls the driving speed of a conveyor 21a to cancel this difference. Thus, prescribed quantities of heavy oil and coal which should be in a prescribed mixture ratio are supplied from a tank 1 and a hopper 2 to a mill 3, and a mixed fuel having a prescribed coal concentration is discharged from the mill 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for sub-controlling the degree of mixture of two or more strains in a mixed liquid containing a liquid.

A mixed fuel that has recently been widely used as clam feed for blast furnaces.
For example, it is well known that the combustibility and calorific value of mixed fuels such as coal and heavy oil or tar are greatly influenced by the concentration of coal contained in the mixed fuel. It is necessary to accurately set the coal concentration in the mixed fuel by adjusting the mixing ratio of fuel oil and heavy oil or tar, but the measurement of coal concentration, which is a tortuous process, has not been done in the conventional way. Ta. In other words, the relationship between the coal concentration and density in mixed fuel is investigated on a large number of extracted samples, and a relational expression between the two is determined in advance using the multiple regression method, and when the actual mixed fuel is manufactured, the actual density and @ 11F relational expression to determine the concentration from the density, or by focusing on the fact that the coal concentration in the mixed fuel is related to the amount of attenuation of the ultrasonic waves in the mixed fuel, and measuring the attenuation of the ultrasonic waves. A method of calculating the density f using the following method was adopted.

However, in this method, the density itself changes in accordance with the IiA & of the object to be measured, or changes in the components of coal, heavy oil, etc., so the relational expression must be corrected in accordance with these disturbance factors. The present invention was developed in view of the above circumstances, and its purpose is to determine the density and temperature of each mixture before mixing to produce a Tt mixed liquid. An arithmetic expression for determining the concentration of the to-be-mixed substance is determined based on the density of the mixed liquid and #-j11 degrees, and based on this arithmetic expression, the concentration of the to-be-mixed substance in the mixed liquid can be calculated and controlled by one setting. This is to provide a method for the fC@C system. In the process of producing a total mixed liquid by mixing two or more types of mixed substances according to the concentration control method of the present invention, based on the w and v of each mixed substance before mixing and the density of the mixed liquid, - The purpose is to calculate Il#' in the mixed liquid and control the mixing ratio of the above-mentioned - to be mixed in order to make the # concentration match a predetermined amount.

Hereinafter, the present invention will be specifically explained in the case where it is applied to producing a coal-heavy oil mixed fuel (COM) by mixing coal and heavy oil. FIG. 1 is a schematic diagram showing the implementation state of the concentration control method according to the present invention (hereinafter referred to as the method of the present invention).
In the figure, 1 shows a tank for heavy oil, which is the sample fuel, 2 a hopper for coal, and 3 a ball mill for mixing coal and heavy oil.

Heavy oil heated to a predetermined temperature is stored in the tank 1, and this heavy oil is fed toward the pump II/trowel hole mill 3 side, but the supply amount is controlled by the heavy oil supply amount control device 12 along the way. and the density meter 13. Thermometer] Density γ at 4. , After measuring the temperature above 〇, ball mill 3r
IC will be supplied.

Supply amount control device 12#: is a flow rate regulating valve 12' installed in the heavy oil supply path, which is composed of a flW meter 12b and a supply amount regulator 12a, and is configured to supply a predetermined amount of heavy oil to the supply amount regulator 120.
When a command signal is input to set Vc, the flow meter 12b
The system compares the fuel oil supply level read from the flow rate with the currently flowing heavy oil supply level, and sends a signal to the flow control valve 12a to adjust its opening degree in order to eliminate the difference.

On the other hand, coal that has been crushed to an appropriate particle size is stored in the hotpot 2vc in advance, and is supplied to the ball mill 3 while the amount of coal being supplied is adjusted by the coal cutting device 2XK. A belt conveyor 21aj is attached to the coal cutting device 21! Measure a
xb, a conveyor motor 21c, a coal supply amount controller 2d, etc., and when a command signal is input to the supply amount regulator 21 (l) to supply a predetermined amount of coal, the weighing scale 21b
The amount of coal currently being supplied is determined based on the read coal weight, and this is compared with the set value. In order to match the set value, the motor 21c sends a K signal and adjusts the drive speed of the belt conveyor 21. I told K to do it.

The ball mill 3 is designed to mix and melt a predetermined amount of heavy oil supplied from the tank 1 and a predetermined amount of coal supplied from the hopper 2, and send the mixed fuel to a collect tank (not shown) K. A mixed fuel density meter 31 is installed in the mixed fuel flow path from the ball mill 3 to the collection tank. A hygrometer 32 is provided, and a density meter 31 is provided for mixed fuel. V
After measuring density 71 and temperature 11 with A degree meter 32,
You will be led to the collection tank.

4 is a calculation unit which reads the heavy oil density To before mixing, that is, before reaching the ball mill 3, from the density meter 13 and the electric oil humidity t6 before mixing from the thermometer 14;
The density T1 of the mixed liquid itself is read from the density meter 31, and the temperature ti of the mixed liquid is read from the thermometer 32.

Since it is difficult to measure the coal density rc before tip mixing online, the density is determined for each brand in advance and calculated f!
Give it to A4. 4 calculation departments First, according to the following formula (1), the heavy oil density (apparent density) γ when mixed at temperature tS&C
・Calculate t and get 1 γ. t=γ. +1(ts -ts) ...(
1) However, a: Articles of Incorporation Then, calculate the coal concentration P in the mixed fuel according to the following equation (2).

What is the desired coal concentration for the mixed fuel in advance for calculation s4? . The coal concentration t in the mixed fuel calculated by the four calculation units is compared with P, and the new mixing ratio of heavy oil and coal is determined as necessary to make the coal concentration - match the set value pa. Based on this mixture ratio and the required mixed fuel supply amount (production amount), the amount of heavy oil and coal to be supplied is determined, and a command signal is issued to the control unit 5. Based on the above-mentioned input signal, the control unit 5ti inputs the amount of heavy oil and the amount of coal to be supplied to the heavy oil supply amount regulator 12C and the coal supply amount regulator 21d as set values, respectively.

Therefore, as mentioned above, the heavy oil supply flki 4 section 12c
When the K set value is given, the flow rate of heavy oil is read from the flow meter 12b, the amount of heavy oil currently being supplied is calculated, this is compared with the new set value, and the flow control valve 12aK is operated to eliminate the difference. A command signal is issued to adjust the opening degree.

Also, when the coal supply amount regulator 21dK setting value is given, the weight of coal is read from the weighing scale 21b, the amount (weight) of coal currently being supplied is calculated, this is compared with the new setting value, and the coal weight is calculated. In order to eliminate the difference, the motor 21c and the K conveyor 21aO issue a command signal to adjust the assist speed. Therefore, from tank 1 and hopper 2, heavy oil and coal with a predetermined mixing ratio and a predetermined amount are sent to the ball mill 3KMM.
As a result, mixed fuel having a predetermined coal concentration is delivered from the ball mill 3.

In normal cases, the amount of coal supplied is ll# #lK i#
Since it is easier to control the amount of heavy oil supplied than to control the amount of fuel oil supplied, it is possible to determine the required production amount of mixed fuel, determine a predetermined amount of coal supplied accordingly, and control the coal concentration in the mixed fuel. This is often done by adjusting the amount of heavy oil supplied, but in this case, control is performed as follows. That is, the production amount of mixed fuel and the required amount of coal to be supplied for this are given to the calculation unit 4, and the coal concentration is set based on these data and the coal concentration in the mixed fuel determined according to (2) 2. The amount of heavy oil required to match the value C0 is calculated and given as the heavy oil supply amount regulator 12clC setting value via control s5, and the amount is supplied to the coal supply amount regulator 2.
1dK provides only a predetermined setting value. Due to this busy operation, a fixed amount of coal is constantly cut out from the hopper 2, and only the amount of heavy oil supplied from the tank 1 is controlled.

Figure 2 is a graph showing the coal concentration in the mixed fuel calculated based on the above-mentioned formulas (1) and (2) in comparison with the coal concentration in the mixed fuel obtained separately by 'f-analysis. , plotted as a black circle in the grab. As is clear from this graph, the coal concentration used in the method of the present invention remains within a range of ±1% compared to the coal concentration determined by manual analysis, proving that its accuracy is extremely high.

The above explanation is based on the case where the coal concentration in the mixed fuel is controlled in the process of producing a mixed fuel by mixing coal and heavy oil, but it is also possible to control the coal concentration in the mixed fuel, Of course, it can also be applied to controlling the concentration of substances to be mixed in a liquid mixture produced from.

As described above, in the method of the present invention, the degree of f & mixture in the mixed liquid is calculated and controlled based on the density of each to-be-mixed substance before mixing and the density of the mixed liquid, so it is extremely accurate. This provides an excellent effect of being able to perform high-level control at once.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the implementation status of the method of the present invention, and FIG. 2 is a graph 57 showing a comparison between the concentration value calculated by the method of the present invention and the concentration value obtained by manual analysis. l...Tank 2...Hopper 3...Ball mill 4...Calculation section 5...Control section 11...Pump
12...Heavy oil supply control device 12m...Flow rate control valve 12b...Flow meter 12c...Heavy oil supply amount regulator 13...Density meter 14...Thermometer 21...
Coal cutting device 21m...Conveyor 21b...Weighing meter 21c...Motor 21d...Coal supply amount regulator 31...Density meter 32...Temperature timer Applicant: Sumitomo Metal Industries, Ltd. agent patent attorney
Noboru Kono Dog 30 40 50 Intervention iJ & Rate 2 Figure 68-

Claims (1)

[Claims] 1. In the process of producing a mixed liquid by mixing two or more types of mixed substances including liquids, the concentration of - in the mixed liquid of the mixed substances based on the density of each mixed substance before mixing and the density of the mixed liquid. 1. A concentration control method characterized by controlling the mixing ratio of the to-be-mixed substances in order to make the concentration match a predetermined value.