JPS59158737A - Quantitative delivery controlling method of powdery granule - Google Patents

Abstract

PURPOSE:To make the quantity of delivery alterable in a speedy manner, by letting a device perform the delivery of powdery granules after setting pressure inside a tank at the stand-by side to the specified pressure in time of altering the delivery quantity, in case of a device which delivers these powdery granules inside each of pressure tanks plurally installed inside. CONSTITUTION:In the case where, in two pressure tanks 11 and 12 storing powdered coal inside, for example, the powdered coal of one side pressure tank 11 is delivered via an on-off valves 21 and a rotary feeder 31 and fed to the specified position together with carrier gas by an ejector 41, if the quantity of delivery is altered, first pressure inside the other side pressure tank 12 being in a stand-by state is set to pressure P to be determined according to the quantity of delivery. Then, a rotary feeder 32 is adjusted to revolution R to be determined likewise according to the quantity of delivery. Afterward, each of on-off valves 21 and 22 is operated whereby delivery of the powdered coal is changed over to the pressure tank 12 from the tank 11.

Description

[Detailed description of the invention] This issue H1-i relates to a method for controlling quantitative cutting of powder or granular material.

In the past, the fuel used in blast furnaces was coke, but with the development of blast furnace technology, heavy oil has been blown from the tuyere into the blast furnace as an auxiliary fuel.Furthermore, reflecting the recent energy situation, heavy oil has been replaced. Attempts to use pulverized coal have been made extensively, and the development of flow rate control for pulverized coal is currently underway in order to improve combustion efficiency and save fuel.

Various methods have been developed for controlling the constant volume cutting of powder and granular materials such as pulverized coal, but all of them are related to how to supply a constant flow rate against disturbances, and are difficult to control in continuous supply. , child? When changing the feI amount, it takes time for the supply amount to become stable without fluctuations, and there is no established method for stabilizing the supply amount in a short period of time. . In the multi-tank system, powder and granules are stored in multiple pressurized tanks, and continuous supply is possible by selectively cutting the powder and granules from each pressurized tank to a common supply pipe. When cutting out powder or granules from a pressurized tank, a control method for changing the cut-out amount is to change the ej mechanical discharge device of the pressurized tank that is cutting out, and use it as the changed cut-out amount. After *V, the pressure inside the tank is controlled to a constant level, or by controlling the differential pressure between the pressure inside the pressurized tank and the pressure at the outlet of the discharge device, quantitative cutting is performed. However, with this method,
Operating the discharge device will cause large fluctuations in the pressure inside the tank, the pressure in the supply pipe for the powder and granules after cutting, etc. Therefore, after operating the discharge device, the tank pressure or the difference between the inside of the tank and the outlet of the discharge device will change significantly. Even if the differential pressure is controlled, the amount of cutout remains constant.
It was not possible to smoothly change the cutting amount, and with regard to constant voltage cutting, it was not possible to meet the requirements of cutting a constant amount at a stable L7 and smoothly changing the cutting amount to the Renci cutting amount.

Unexploded L-Il:I was made by pressing a button on a certain skewer, and multiple pressurized tanks were installed to ensure continuous supply.
The purpose of the present invention is to provide a constant wholesale cutting control method that enables smooth and stable supply even when changing the cutting amount using a multi-tank system including hk and L7.

In the present invention, continuous supply is possible by providing a plurality of pressurized tanks ft for storing powder and granular material, and cutting out one piece of powder from one of the pressurized tanks to a common supply pipe. In the stationary cutting control method for powder and granular material, after changing the pressure in the d-1 standby pressure tank to the pressure corresponding to the cutting amount during νJ dispatch, the pressure in the standby 1 t tank is changed. The method of the present invention is described below in detail based on an example in which pulverized coal is used as the powder.

FIG. 1 is a schematic diagram of the apparatus used to carry out the method of the present invention, in which two pressure tanks 11 and 12 are arranged in parallel on a supply pipe 5, which is a conveyance line, and a counter-pressure tank 11 and a 1
Pulverized coal is conveyed and supplied into the chamber 2 and stored therein. At the lower outlet of the valley tank 11.12, on-off valves 21.22 for supplying and stopping pulverized coal to a rotary feeder 31.32 as a mechanical discharge device are installed. 22 is opened, and the fine powder cut out from the pressurized tank 11.12 by the rotary feeder 31.32 is
The ejectors 41 and 42 turn the inside of the supply pipe 5 into a gas-solid two-phase fluid along with the carrier gas, and feed it to the folding position.

For νJ extraction of pulverized coal using a multi-tank evening system having a plurality of pressurized tanks, one pressurized tank is used alternately to perform all the cutting selectively, and the other pressurized tanks are used to
After storing pulverized coal in a tank, it is pressurized and on standby.

If pulverized coal is currently being cut out from one pressurized tank 11 and the other pressurized tank 12 is on standby, if it becomes necessary to change the cut amount, the pressurized tank on standby will be After setting the pressure in the rotary feeder 32 to a pressure PK level determined according to the cutout amount, the rotary feeder 32 is set to the rotation speed R, which is also determined according to the cutout amount, by υM, and the on-off valve is set. The cutting operation is switched from the pressurized tank 11 to the pressurized tank 12 by the operations 21 and 22.

The relationship between the pressure P applied to the H2 tank 12 during standby and the rotation speed R of the rotary feeder is as follows.

FIG. 2 is a graph showing an example of the relationship between the amount of pulverized coal cut out and the pressure inside the supply pipe 5 (rotary feeder outlet side pressure) P'. If removed, the gradual feed amount, IIJ, is proportional to the cutout amount. This relationship is determined by the characteristics of the granular material such as pulverized coal and the piping characteristics.

Therefore, based on the lever graph t, the supply v5 internal pressure P' is calculated from the required cutting amount.

Figure 3 shows the relationship between the differential pressure ΔP of the rotary feeder (i.e., the differential pressure P-P' between the tank internal pressure P and the supply pipe internal pressure P') and the amount of pulverized coal pushed out, and the rotation speed of the rotary feeder. It is shown for each R. Based on the given relationship, the differential pressure ΔP between the tank internal pressure P and the supply pipe internal EE force P' and the rotation &R of the rotary feeder can be determined from the required cutting amount.

The pressure P'+ΔP2P, which is the sum of the supply pipe 5 internal pressure P' found in this way and the differential pressure ΔP of the rotary feeder, is added to the pressure tank 12, and the rotary feeder 32 of the broken pressure tank 12 is As soon as the rotation speed R is set to a predetermined value,
When the on-off valve 21 is closed and the on-off valve 22 is opened L7, and the cutting of pulverized coal is switched from the pressurized tank 11 to the pressurized tank 12, the amount of pulverized coal cut into the supply pipe 5 will change after a short period of time (several minutes). After that, stable pulverized coal cutting becomes possible.

The implementation results according to the method of the present invention and the implementation results according to the conventional method are shown in FIG. This was done by adjusting the rotation speed.Now,
Pressurized tank internal pressure P is 3.75 kg/cm2, o
- The number of revolutions R of Cliff Ida is 7 r, p, m.

The pressure inside the supply pipe P' is 3.7 k (1/cm2) The feed rate of carrier gas is 15 ONm'/H, the differential pressure ΔP of the row feeder is 500 mmH2O, and the cutting amount is I
In the case of 2TiHvvw from T/H, in the conventional method, the rotary lift of the pressurized tank where cutting is performed
In contrast to the method of the present invention, the rotation speed R of the row feeder in the pressurized tank during standby is doubled to 14. r,p
, and the tank power is 5.75A:S/cm.
2. As a result, in the conventional method, Fig. 4 (a)
As shown in Figure 4, it took about 20 minutes for the cutting amount to stabilize after changing the cutting amount, whereas the method of the present invention requires approximately 20 minutes to stabilize the cutting amount, as shown in Figure 4 (b). The time required for stabilization was about 1 minute.

As detailed above, according to the present invention, it is possible to smoothly increase the amount of powder and granules cut out within a short period of time, and, for example, improve the stability, operation, and combustion efficiency of the blast furnace. The present invention provides excellent effects.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the equipment used to carry out the method of the present invention, the second figure is a graph showing the relationship between the amount of pulverized coal cut and the pressure inside the supply pipe, and the third figure is a graph showing the relationship between the differential pressure of the rotary feeder and the lack of fine powder. A graph showing the relationship with the cutting amount for each rotation speed of the rotary feeder. Figure 4 (a) is a graph showing the change in the cutting amount when changing the cutting amount of pulverized coal using the conventional method. ) is a graph showing the change in cutting amount according to the method of the present invention. 11.12 - Pressurized tank 21, 22... Open/close valve 31.32... Rotary feeder 41. 42...
・Ejector 5... Supply pipe patent Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Yusuke Noboru Daishi 2 Ki 1 Figure 0 1 2@#
Coal paddy soil volume (T/H) %2 figure

Claims (1)

[Claims] 1. Install multiple 4vA pressurized tanks to store powder and granular materials.
In a method for controlling the quantitative cutting of powder and granular material in which continuous supply is achieved by selectively cutting out the powder and granular material from either pressurized tank to a common supply pipe, during the cutting process, A method for controlling quantitative cut-out of powder or granular material, characterized in that after setting the pressure in a stand-by pressurized tank to a pressure corresponding to the changed cut-out amount, fixed-quantity cut-out is performed using the stand-by pressurized tank.