JPS6058132B2 - Powder distribution air transport method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air transportation method for distributing and supplying powder and granules filled in a pressurized tank to a plurality of receiving ends using a transport gas, and particularly to blast furnaces, This is suitable for stably supplying combustible powder such as pulverized coal or coke to a receiving device such as a cement kiln which has a constant pressure and has a plurality of receiving ports.

In this type of powder distribution and transportation method, quick response to changes in powder transportation conditions is required in order to ensure a constant flow rate of the distributed and transported powder and granules.

In addition, if the distance to the receiving end of each transport pipe, that is, the equivalent length of the pipe, differs, the flow rate of powder and granules cut out through each transport pipe changes in inverse proportion to the equivalent length of the pipe, and the flow rate of the powder and granules cut out through each transport pipe changes, resulting in equal distribution or required ratio distribution. This has become an obstacle to carrying out the

The present invention calculates a solid-gas mixture ratio based on the total flow rate of powder cut out from a pressurized tank and the total flow rate of transport gas, and adjusts the transport gas flow rate of each transport pipe so that this solid-gas mixture ratio is constant. It is an object of the present invention to provide a novel air transportation method for distributing powder and granular material, which can easily and accurately distribute and transport powder and granular material in a required proportion with high-speed responsiveness.

Embodiments of the apparatus of the present invention will be described below with reference to the drawings. In the figure, 1 is a pressurized tank having a powder input valve 2 at the top and a fluidized bed 3 at the bottom, and 4 is a pressurized gas supply pipe that supplies pressurized gas to the gas chamber 5 below the fluidized bed 3. A pressure regulating valve 6 is interposed in the pressurized gas supply pipe 4, and this regulating valve 6 connects the detected output of the pressure detector 7 that detects the pressure of the gas chamber 5 to the output of the pressure regulator 8 supplied with the pressure. Therefore, the pressure in the gas chamber 5 is controlled at a constant value to a required value. 9 is a pressure reducing valve installed in the pressurized gas supply pipe 4, and 10 is a measuring device such as a load cell for measuring the weight of the tank.

Ti (where i=1, 2,...N) are transport pipes connected to the pressurized tank 1, and their openings 14 are extended into the pressurized tank 1 and are closely opposed to the fluidized bed 3. There is.

VTi is a transport valve installed outside the pressurized tank 1 of each transport pipe Ti, and is operated to be fully open during transport and fully closed when not transporting. B1 is a transport gas supply pipe connected to the secondary side of the transport valve VTl of each transport pipe Ti, each of which is equipped with a flow rate regulating valve VFi and a flow rate detector FDi, and a flow rate regulating valve VFi and a flow rate detector FDi are interposed therein. The output is supplied to a flow rate regulator FCi, which operates a flow rate regulating valve VFi to maintain the transport gas flow rate at a desired value.

The pressurized gas supply pipe 4 and the transport gas supply pipe Bi are connected to each other and connected to one pressurized gas supply source 11, and a flow rate detector 12 for detecting the total transport gas flow rate is interposed on the way. .

Then, the output SW of the measuring instrument 10 and the output F of the flow rate detector 12 are supplied to a solid-air ratio controller 13 that calculates the solid-air mixture ratio of the entire transportation system, and the output SW is divided by the output SF. By doing this, the solid-gas ratio is calculated.

The output of the solid-gas ratio controller 13 is supplied to the flow rate controller FCi via the ratio setter Ri, which is set with a correction coefficient corresponding to the equivalent length of each transport pipe Ti, and is cascade-controlled.

Therefore, the solid-gas ratio is calculated based on the total flow rate of the powder and granular material cut out through each transport pipe Ti and the total flow rate of the transport gas,
Each flow control valve VF is adjusted so that the solid-air ratio is maintained at a required value.
i is manipulated. Next, to explain the operation of the above-mentioned device of the present invention, first, the transport valve ■Tl is closed, and the pressure regulating valve 6 is closed.
is closed and the pressurized tank internal pressure Pt is set to normal pressure, and the pressurized tank 1 is filled with powder and granular material via the input valve 2. Then, the input valve 2 is closed and the pressure control valve 6 is opened to control the flow. Pressurized gas is supplied to the bed 3 to increase the pressure inside the pressurized tank to a required value.

Next, the main valve VOi is opened to supply transport gas into the transport pipes Ti, and then all the transport valves VTi are closed so that the powder and granules in the pressurized tank 1 are supplied to each transport pipe Ti according to the flow rate of the transport gas. The fuel is then sent to a receiving port such as a blast furnace tuyere or cement kiln fuel supply port.

When the transportation of the powder or granular material is started, the pressure inside the pressurized tank 1 is controlled to a constant value by the pressure control valve 6, and the pressure inside the pressurized tank 1 is controlled to a constant value by the
The supply end pressure of the transport pipe TN-1 is constant and does not fluctuate.
Assuming that the equivalent pipe length of TN is TN-1>TN, the tank weight change rate DW/Dt (K9/H), which represents the amount of powder and granular material cut out with respect to the solid-air ratio M (K9/K9), is expressed as follows: It will look like Figure 2. That is, even if the solid-air ratio M is constant, the amount of powder or granular material cut out varies depending on the difference in the equivalent length of the piping. In addition, the amount of powder and granular material cut out Dw/Dt with respect to the transport gas flow rate QBi is expressed as shown in Fig. 3, and in order to keep the amount of powder and granular material discharged constant, the transport gas flow rate from the transport gas supply pipe Bi must be adjusted. It turns out to be a good thing. Furthermore, the relationship between the transport gas flow rate QBl and the solid-gas ratio M is expressed as shown in Fig. 4, and the transport gas flow rate QBi of other transport pipes Ti is set as a ratio with the transport pipe Tl having the shortest or longest piping equivalent length as a reference. By adjusting the ratio to the required ratio using the container Ri, the flow rate of the powder and granular material transported through each transport pipe Ti can be made uniform or controlled at the required ratio.

As described above, according to the present invention, the total flow rate of powder and granular material cut out from a pressurized tank to a plurality of transport pipes and the total flow rate of transport gas are detected to calculate the solid-gas mixture ratio of the entire transport system, and the solid-gas mixture ratio of the entire transport system is calculated. Since the transport gas flow rate of each transport pipe is controlled so that the mixing ratio is constant, the powder and granules can be distributed equally or in the required ratio to each transport pipe, regardless of the difference in the equivalent length of the pipes. It has excellent features such as easy and accurate operation and simple operation.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a powder transport device suitable for implementing the method of the present invention, and FIGS. 2, 3, and 4 are graphs for explaining the operation of the method of the present invention. 1... Pressurized tank, 3... Fluidized bed, 4
..... Pressurized gas supply pipe, 6 ..... pressure control valve, 10 ..... meter, 12 ..... flow rate detector, 13 ..... Solid-air ratio controller, Ti...
Transport pipe, Bi... Transport gas supply pipe, Ri...
...Ratio setting device, ■Fi...Flow rate control valve, F
Ci...Flow rate controller.

Claims (1)

[Claims] 1. A plurality of transport pipes are connected to a pressurized tank filled with powder and granular material, and the internal pressure of the pressurized tank is controlled to a constant value, and the internal pressure of the pressurized tank is controlled to a constant value, and a plurality of transport pipes are connected to each of the transport pipes based on the measurement signal of the pressurized tank. Detects the total amount of powder and granular material cut out, and also detects the total amount of transport gas necessary to transport the powder and granular material, calculates the solid-gas mixture ratio based on these, and maintains the solid-gas mixture ratio constant. A method for distributing and transporting powder and granular material by air, characterized in that the transport gas flow rate ratio of each transport pipe is changed so that the amount of powder and granular material cut out to each transport pipe is distributed and transported equally or at a required ratio.