JPH0548803B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inert gas replacement method and apparatus that are particularly effective when replacing an asphalt mixture silo with an inert gas.

[Prior art] For example, in an asphalt plant, when storing mixed materials in a silo for a long time (up to about 72 hours), an inert gas such as carbon dioxide is supplied into the silo to remove the air inside the silo. This prevents oxidation (deterioration) of the composite material due to oxygen in the air.

[Problems to be Solved by the Invention] By the way, the above-mentioned conventional method of supplying inert gas such as carbon dioxide gas has the problem of increasing costs because it is necessary to purchase the inert gas in expensive gas cylinders. It was hot.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and the first invention is to burn fuel in the air inside a sealed container. The fire is extinguished naturally due to the complete consumption of oxygen in the air, and
By supplying water into the container and expanding the volume of water in the container, the gas inside the container after natural extinguishing is transferred from the upper and lower parts of the silo where the asphalt mixture is stored through piping. This method is characterized by supplying it internally. The second invention also provides a container whose upper part communicates with the upper and lower parts of the silo via a pipe having an on-off valve, an air introduction means for introducing and blocking air into the container, and an upper part inside the container. An apparatus characterized in that it is equipped with a combustion device that is installed in a container and burns fuel using air trapped in a container, and a water supply and discharge means that supplies and discharges water to and from the container below the combustion device. be.

[Operation] The first invention burns fuel in the air in a sealed container to completely consume oxygen in the air to produce inert gas. By supplying water into the container and expanding the volume of water in the container, the inert gas filling the container is transferred via piping to the silo where the asphalt mixture is stored. The inside is automatically supplied from the upper and lower parts. The gas inside the silo is then replaced with inert gas.

Further, in the second invention, when air is introduced into the container, the on-off valve of the piping having the on-off valve is closed, the air introduction means is closed, and the water supply/discharge means is closed. , the air inside the container becomes airtight. When the fuel is burned in the combustion device in this state, the oxygen in the air within the container is gradually consumed, and when the oxygen is exhausted, the fuel naturally extinguishes. At this time, the inside of the container is filled with inert gas.

Next, when the on-off valve is opened and water is supplied below the combustion device by the water supply/drainage means, the water level in the container rises, and as the water level rises, the inert gas in the container opens the on-off valve. The silo is supplied from the upper and lower parts of the silo through piping. This results in
The air inside the silo is forced out and replaced with inert gas. When the lower side of the combustion device in the container is filled with water, the water supply by the water supply/discharge means is stopped, and the on-off valve is opened. Then, the air introduction means is opened, and the water in the container is discharged to the outside of the container by the water supply and discharge means. As a result, the water level in the container decreases, and air is introduced into the container through the air introducing means. When the water in the container is discharged and the container is filled with air, the air introduction means and the water supply/discharge means are closed. The air inside the container is then sealed again. In this state, the fuel in the combustion device is ignited in the same manner as above to produce inert gas. Thereafter, inert gas is supplied into the silo in the same manner as above, and the air in the silo is replaced with the inert gas.

[Example] Hereinafter, an example of the present invention will be described with reference to FIG.

In the figure, numeral 1 is a container and 2 is a water tank.

The container 1 has a base part 1a installed on a base G.
It consists of a side wall 1b constructed on a foundation 1a, and a roof 1c for closing the upper opening of the side wall 1b, and is completely airtight from the outside air. Inside this container 1, there is a floor 1d near the roof 1c.
is provided. The floor 1d is covered with a net-like expanded metal 1e.
A kerosene stove (combustion device) 3 is placed on top of d. Further, a non-contact type sensor (flame eye, etc.) 4 is provided on the roof 1c of the container 1 to monitor the combustion status (ignition, extinguishing, etc.) of the oil stopper 3. Furthermore, the roof 1c of the container 1 is provided with a pipe 6 that communicates with the asphalt mixture silo 5. The piping 6 is provided with a stop valve (opening/closing valve) 6a in the middle, and the end of the stop valve 6a is bifurcated. The tips of the bifurcated portions are connected to the top surface of the silo 5 and the lower conical portion (hopper portion) of the silo 5, respectively. The silo 5 stores asphalt mixture transported by a transport device (not shown) such as a conveyor.
Further, on the roof 1c of the container 1, a pipe 7 is provided as an air introduction means for introducing outside air into the container 1 via a stop valve 7a. Further, on the inner surface of the side wall 1b of the container 1, a floor 1d and a base portion 1a are provided.
An upper limit water level gauge 8a and a lower limit water level gauge 8b are provided between the upper limit water level gauge 8a and the lower limit water level gauge 8b. The upper limit water level gauge 8a is for sensing the upper limit of water W supplied into the container 1, and the lower limit water level gauge 8b is for sensing the lower limit of water W.
Further, in the vicinity of the base portion 1a of the side wall 1b of the container 1, a pipe 9 is provided as a water discharge means for discharging the water W in the container 1 into the water tank 2 through a stop valve 9a.

The water tank 2 is formed below the surface of the base G, and its bottom surface and peripheral surface are made of concrete to be liquid-tight.

A pump 10 is installed on the bottom of the water tank 2 as a water supply means. A pipe 11 is connected to the pump 10 so that water W discharged from the pump 10 is supplied to the lower side of the floor 1d.

Reference numeral 12 is a control device which receives signals from the sensor 4 and the upper and lower limit water level gauges 8a and 8b to ignite the kerosene stove 3, open and close the stop valves 6a, 7a, and 9a, turn on the pump 10, etc.
This is to control OFF. 13 is Silo 5
This is an exhaust pipe having a check valve 13a provided at the upper part of the exhaust pipe.

Silo 5 is installed by the device configured as described above.
In order to send an inert gas into the container, first the water W in the container 1 is
The control device 12 is operated in a state where water is drained.
Then, the control device 12 closes the stop valves 6a, 7a, 9a, and the oil stove 3
is ignited. At this time, the sensor 4 confirms ignition. The combustion of the kerosene consumes the oxygen in the air within the container 1, and the fire in the oil stopper 3 naturally goes out when the oxygen is exhausted.
As a result, the inside of the container 1 is filled with an inert gas consisting of carbon dioxide gas. When the sensor 4 detects that the fire has been extinguished, the stop valve 6
When a is opened, the pump 10 is turned on and water W is sent from the water tank 2 to the container 1. As a result, the water level in the container 1 gradually rises, the inert gas filled in the container 1 is supplied into the silo 5 through the pipe 6, and the air in the silo 5 is exhausted through the check valve 13a. It is discharged to the atmosphere from the pipe 13,
Displaced by inert gas. Next, container 1
When the water level within reaches the upper limit water level gauge 8a, the stop valve 6a is closed, the pump 10 is turned off, and the transfer of water W is stopped. Also,
At this time, stop valves 7a and 9a are opened, water W in container 1 is drained into water tank 2 through piping 9, and air is introduced into container 1 through piping 7. When the water level in the container 1 decreases and reaches the lower limit water level gauge 8b, all the stop valves 6a, 7a, 9a are closed. In this state, the kerosene stove 3 is lit again. Thereafter, the same cycle as above is repeated, and the inside of the silo 5 is replaced with inert gas.

According to the inert gas replacement method as described above, by burning kerosene in the container 1, the air in the container 1 can be easily changed into an inert gas at low cost. Therefore, inert gas can be produced at extremely low cost, and the cost required for replacing the silo 5 with inert gas can be reduced. Furthermore, the fire in the kerosene stove 3 will naturally go out when the oxygen in the air is gone, so there is no risk of fire and it is safe. Furthermore, by supplying water W into the container 1, inert gas can be reliably and safely supplied into the silo 5. Furthermore,
Inert gas is automatically produced and automatically supplied to the silo 5 by controlling the oil stop 3, stop valves 6a, 7a, 9a, etc. with the control device 12.

Note that the volume and number of containers 1 above are based on the silo 5.
Determined by the cardinality and container of

Further, in the above embodiment, a method of replacing inert gas in a silo for asphalt mixture was described, but the present invention can also be applied to other silos.

[Effects of the Invention] As explained above, according to the inert gas replacement method for a silo of the present invention, inert gas is produced in the container by simply burning fuel in the air inside the sealed container, and furthermore, The inert gas in the manufactured container is automatically supplied to the silo by simply supplying water into the container and expanding the water volume, so a dedicated device to generate inert gas or a gas supply device to the silo is required. It is possible to obtain an inert gas replacement method that significantly reduces running costs without using any of the following.

Furthermore, according to the second invention, the inert gas produced in the container is supplied from the upper and lower parts of the silo, thereby increasing contact with the asphalt mixture in the silo, thereby effectively reducing the It is possible to obtain an inert gas replacement device for a silo that prevents oxidation of asphalt mixture. In addition, when the oxygen in the air in the silo runs out as the fuel burns, the fire will naturally go out, so there is no risk of fire.
Since it can be used as a means of extinguishing a fire in an emergency, it is a device with increased safety.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention. 1... Container, 3... Oil stove (combustion device),
5...Silo, 6a...Opening/closing valve, 10...Pump.

Claims (1)

[Claims] 1. Fuel is burned in the air inside a sealed container, and the oxygen in the air inside the container is completely consumed to cause natural extinguishment, and water is supplied into the container to extinguish the air inside the container. By expanding the volume of water,
A method for replacing an inert gas in a silo, which comprises supplying gas in a container after natural fire extinguishment to the inside of the silo from the upper and lower parts of the silo in which asphalt mixture is stored via piping. 2. A container whose upper part communicates with the upper and lower parts of the silo via piping having an on-off valve, an air introduction means for introducing and shutting off air to the container, and a container provided at the upper part of the container. An inert gas silo characterized by comprising a combustion device that burns fuel using air trapped inside the silo, and a water supply/discharge means for supplying and discharging water to and from the container below the combustion device. Replacement device.