JP3990988B2 - Asphalt supply method in asphalt plant - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an asphalt supply method for supplying molten asphalt to a plant body of an asphalt plant that manufactures an asphalt mixture that is a road pavement material.
[0002]
[Prior art]
The asphalt plant is equipped with asphalt supply equipment consisting of multiple asphalt tanks and supply means. When manufacturing the asphalt mixture, the asphalt is taken out from the desired asphalt tank and supplied to the plant body. After weighing, it is put into a lower mixer and mixed with other materials to produce a desired asphalt mixture. Recently, special asphalt mixtures have also been produced, the types of asphalt used have increased, and different types of asphalt can be stored in asphalt tanks.
[0003]
In the conventional asphalt supply equipment, asphalt in multiple asphalt tanks is circulated to the tank through a supply pipe that supplies the asphalt metering tank in the plant body and a directional control valve on the downstream side of the pump installed in the supply pipe. And a return pipe. When the asphalt is supplied, the pump is driven to supply the asphalt to the asphalt metering tank of the plant main body. When the metering is completed, the direction switching valve is switched so that the asphalt flows through the return pipe and circulates in the tank. When different types of asphalt are used by switching the asphalt tank, the asphalt from the previous use remains in the supply pipe leading to the asphalt measurement tank of the main body of the plant, but this remaining asphalt together with the asphalt used this time is planted. It is used by supplying to the asphalt measuring tank of the main body.
[0004]
[Problems to be solved by the invention]
However, in the conventional asphalt supply equipment, when the use of the asphalt tank is switched, different types of asphalt remaining in the supply pipe leading to the asphalt measurement tank of the plant body are used, which adversely affects the quality of the asphalt mixture. There was a possibility of affecting.
[0005]
BACKGROUND OF THE INVENTION
In view of the above points, the present invention provides an asphalt supply method in an asphalt plant in which mixing of different types of asphalt is reduced at the time of switching the use of an asphalt tank so as not to adversely affect the quality of the asphalt mixture. Is an issue.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, in the asphalt supply method in the asphalt plant of the present invention, a plurality of asphalt tanks for storing different types of asphalt, and various asphalts in the asphalt tank are measured by asphalt metering of the plant body. In an asphalt supply method in an asphalt plant comprising a supply pipe to be supplied to a tank, a pump for asphalt supply arranged in the supply pipe, and a return pipe connected to the supply pipe downstream of the pump with a direction switching valve interposed therebetween, When the pump can be rotated in forward and reverse directions and the asphalt tank is switched to use different types of asphalt, the direction switching valve is switched so that the asphalt tank supply side and the plant body side can communicate, and then the pump is rotated in reverse. To the asphalt measuring tank of the plant body Is characterized in that so as to recover the previous original asphalt tank type of asphalt used remaining in the tube.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
According to the asphalt supply method in the asphalt plant according to the present invention, the asphalt supply pump is allowed to rotate forward and backward. When the asphalt tank is switched and different types of asphalt are used, the pump is reversely rotated, and the asphalt remaining in the supply pipe leading to the asphalt measuring tank of the plant body is recovered in the original asphalt tank. After this asphalt is recovered, supply of different types of asphalt from other asphalt tanks is started. This eliminates the use of asphalt remaining in the supply pipe that reaches the asphalt metering tank of the plant body when switching to asphalt use, and can reduce the mixing of different types of asphalt and prevent adverse effects on the quality of the asphalt mixture as much as possible. .
[0008]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0009]
The asphalt supply facility 1 includes a supply pipe 3 for supplying asphalt in a plurality of asphalt tanks A, B, and C to the plant body 2 and a direction switching valve 5 on the downstream side of a pump 4 installed in the supply pipe 3. And a return pipe 6 for circulating asphalt. The pump 4 is rotatable forward and backward so that asphalt can be supplied to the plant side or returned to the tank side.
[0010]
Further, the take-out pipe 7a of the asphalt tank A is connected to the supply pipe 3, the intake pipe 8a is connected to the return pipe 6, and the take-out pipes 7b and 7c of the other asphalt tanks B and C are interposed with the direction switching valves 9b and 9c. The intake pipes 8b and 8c are connected to the return pipe 6 via the direction switching valves 10b and 10c. Further, the tip of the supply pipe 3 is extended to the plant main body 2 having functions of storing, measuring, and mixing asphalt mixture materials, and is connected to an asphalt measuring tank 12 provided in the plant main body 2 through a measuring valve 11. .
[0011]
When supplying asphalt from the asphalt tank A, the flow direction of the direction switching valves 5, 9b, 9c, 10b, and 10c is switched as shown in FIG. Is supplied to the plant main body 2 as indicated by the solid line arrow, the metering valve 11 is opened, and a predetermined amount is measured in the asphalt measuring tank 12. When metering of asphalt is completed, the metering valve 11 is closed and the direction switching valve 5 is switched so as to communicate with the return pipe 6 as shown in FIG. 2, and the asphalt passes through the return pipe 6 as shown by the solid arrow. Return to asphalt tank A and wait for the next measurement while circulating. When the next metering starts, the direction switching valve 5 is switched again to the plant body 2 side to supply asphalt to the asphalt metering tank 12.
[0012]
Next, when switching to the use of the asphalt tank B to produce different types of asphalt mixtures, first, the direction switching valve 5 is used to recover the asphalt remaining in the supply pipe 3 leading to the asphalt metering 12 of the plant body 2. Then, the metering valve 11 is opened while the pump 4 is rotated in the reverse direction, and the asphalt remaining in the main supply pipe 3 is collected into the asphalt tank A. As a result of this recovery operation, no asphalt remains in the supply pipe 3 from the pump 4 to the asphalt measuring tank 12. Note that asphalt remains in the pipe from the pump 4 to the asphalt tank A.
[0013]
After completion of the asphalt recovery, in order to supply the asphalt in the asphalt tank B, the direction switching valves 9b and 10b are switched as shown in FIG. 4 and then the pump 4 is rotated forward to take out the asphalt from the asphalt tank B and supply pipes. 3 to supply to the asphalt measuring tank 12. At this time, different types of asphalt remaining in the supply pipe 3 between the pump 4 and the direction switching valve 9b are pushed out and supplied to the asphalt metering tank 30, but the asphalt metering tank 12 of the plant body 2 from the pump 4 is supplied. Compared with the length of the pipe up to, it is short and the extrusion amount is not so much, and there is little influence on the asphalt mixture to be produced. If the direction switching valves 9b and 9c are arranged close to the pump 4, the amount of asphalt to be pushed out is small, which is preferable.
[0014]
Thus, in the present invention, when the use of the asphalt tank is switched, the asphalt remaining in the supply pipe 3 from the pump 4 to the asphalt measuring tank 12 of the plant main body 2 is recovered by rotating the pump 4 in the reverse direction. The use of asphalt can be reduced as much as possible, and adverse effects on the quality of the asphalt mixture produced can be avoided as much as possible.
[0015]
【The invention's effect】
As described above, according to the asphalt supply method in the asphalt plant according to the present invention, a plurality of asphalt tanks for storing different types of asphalt and the supply for supplying various asphalts in the asphalt tank to the asphalt measuring tank of the plant body. An asphalt supply method in an asphalt plant comprising a pipe, an asphalt supply pump arranged in the supply pipe, and a return pipe connected to the supply pipe downstream of the pump through a direction switching valve. When using different types of asphalt by switching the asphalt tank, after switching the direction switching valve so that the asphalt tank supply side and the plant body side can communicate with each other, the pump is rotated in reverse to reverse the asphalt of the plant body. remaining in the supply pipe leading to the measuring tank Since the times used of the kind asphalt to recover the original asphalt tank, asphalt remaining in the supply pipe extending from the pump when using switching asphalt tank asphalt measuring tank of the plant body can be recovered, of different kinds of asphalt Mixing can be reduced and adverse effects on the quality of the asphalt mixture can be avoided as much as possible.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of an asphalt supply method in an asphalt plant according to the present invention.
FIG. 2 is a diagram illustrating a state in which the asphalt of FIG. 1 is circulated.
FIG. 3 is a diagram for explaining a state in which asphalt is recovered by reversely rotating the pump of FIG. 1;
4 is a diagram for explaining a state in which asphalt is supplied from another asphalt tank of FIG. 1; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Asphalt supply equipment 2 ... Plant main body 3 ... Supply pipe 4 ... Asphalt supply pump 5 ... Direction switching valve 6 ... Main return pipe 7a, 7b, 7c ... Extraction pipe 8a, 8b, 8c ... Intake pipe 9b, 9c, 10b DESCRIPTION OF SYMBOLS 10c ... Direction switching valve 11 ... Metering valve 12 ... Asphalt measuring tank A, B, C ... Asphalt tank

Claims (1)

A plurality of asphalt tanks for storing different types of asphalt, a supply pipe for supplying various asphalts in the asphalt tank to an asphalt measuring tank of the plant body, an asphalt supply pump arranged in the supply pipe, and a pump downstream in asphalt supply method in asphalt plant and a return tube connected with intervening directional control valve to the supply pipe, said pump freely forward and reverse rotation, by switching the asphalt tank when using different types of asphalt, After switching the direction switching valve so that the asphalt tank supply side and the plant main body side communicate, the pump is reversely rotated and the asphalt of the type used last time remaining in the supply pipe leading to the asphalt measuring tank of the plant main body is restored . JP that it has to recover the bitumen tank Asphalt supply method in asphalt plants to.

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