JPS6350225B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas treatment device for a tank lorry, and more particularly to a gas treatment device in which flammable gas remaining in a tank chamber is combusted by an engine. This is used in the technical field to prevent flammable gases from exploding due to the charging phenomenon that occurs when liquids are loaded.

[Prior art]

Tank trucks usually load liquids such as gasoline and kerosene into individual tank rooms at a loading base, and when they arrive at a gas station etc., they unload the liquids into underground tanks. At that time, if gas evaporated from the liquid stored in this underground tank remains, unloading will not be carried out smoothly, so it is necessary to discharge the remaining gas. However, simply releasing this gas causes air pollution, so it is introduced into the unloading tank room or another empty tank room and transported to the loading terminal, where it is treated. At the gas processing facility at the base, the gas, which has a higher specific density than air, is led out of each bottom valve in the tank chamber, passed through activated carbon or incinerated in a combustion furnace, and then released into the atmosphere as a harmless gas.

By the way, discharging the gas evaporated from the flammable liquid from the tank chamber is necessary not only to eliminate the air pollution mentioned above, but also to prevent the flammable gas from exploding due to the charging phenomenon that occurs during loading. It is said that That is, in a tank truck, regardless of the number of tank chambers, the type of liquid loaded into the tank chamber and the type of gas introduced for gas treatment often differ each time. Liquid loading work at the loading terminal is carried out by inserting a loading arm into a manhole installed at the top of the tank room. Static electricity is generated accordingly. In particular, when loading light oil or kerosene, the amount of gas generated increases, and a phenomenon occurs in which the liquid becomes positively charged and the tank becomes negatively charged. On the other hand, gas evaporated from gasoline is significantly more flammable than gas evaporated from diesel oil. If such a gas is introduced into the tank room from an underground tank at a gas station and remains in the tank room at a concentration of about 1 to 6%, the above-mentioned static electricity will cause the surface of the liquid to contact the tank wall. This is because if a spark occurs between the two, the accumulated gas will ignite and explode, resulting in an extremely dangerous situation.

The above-mentioned gas processing is carried out at a well-equipped loading base, so it cannot be done unless the tank truck returns to the base, and the processing requires 1Kl of gas.
Since it takes 2 to 2 minutes per time, a large tank truck with a tank capacity of more than 10 Kl requires a lot of time. As a result, even if the tank truck arrives at the loading base, loading cannot be started immediately, which poses a problem that improves the operating efficiency of the tank truck. In addition, each base will be required to install a designated gas processing facility, and will be required to have a complete support system for transporting flammable liquids.

[Purpose of the invention]

The present invention was made in view of the above-mentioned problems, and its purpose is to burn off flammable gas in the tank chamber while the tank truck is traveling until it reaches the loading station, thereby avoiding air pollution, and to avoid air pollution during loading. To provide a gas treatment device for a tank lorry that can avoid explosion within the tank even if sparks are generated due to generated static electricity.

[Structure of the invention]

A feature of the gas treatment device for a tank lorry according to the present invention is that, as shown in FIG. A manual on-off valve 10 is interposed in the gas pipe 4 to adjust the amount of flow.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to drawings of embodiments thereof. FIG. 1 is an overall system diagram showing one embodiment of the gas treatment device, in which each tank chamber 1 is provided with a bottom valve 2 for discharging liquid from its bottom, and a discharge pipe 3 is connected to each bottom valve. ing. Furthermore, a gas pipe 4 for discharging the flammable gas staying therein is inserted into each chamber, and its open end 4A extends to the vicinity of the bottom of the tank chamber in order to completely discharge the gas having a large specific gravity. This gas pipe 4 is unified after passing through a valve 5 provided outside each tank chamber 1 shown in FIG. 2, and the other end is connected to an air intake pipe 7 that supplies air to a diesel engine 6. There is. Then, the introduction pipe 4a of the gas pipe 4
A manual valve 8 is provided at the outlet pipe 4b, and a manual valve 9 is provided at the outlet pipe 4b, and a manual on-off valve 10 whose opening degree can be manually adjusted is interposed between the manual valve 9 and the connecting portion 4B. There is. Therefore, the air supplied to the combustion chamber by the suction negative pressure during the intake stroke of the engine 6 is not only taken in through the air intake pipe 7, but also introduced from the gas pipe 4, and is connected at the connection point 4B. The mixture is mixed and combusted in the engine 6. Note that if the ventilation resistance from the open end 4A of the gas pipe 4 to the connection part 4B is greater than that of the air intake pipe 7 to the connection part 4B, a suction type blower (not shown) may be interposed in the gas pipe 4, or a tank It is preferable to provide a conduit for supplying outside air to the room 1 and to interpose a forced air blower therein. 11 in the figure is an air filter installed in the air intake pipe 7 to purify the intake outside air;
Reference numeral 12 denotes a safety valve attached to the manhole hatch 13, which provides relief when the pressure inside the tank chamber 1 exceeds a set value, and sucks in outside air when the pressure within the tank chamber 1 exceeds a set value.

According to the embodiment having such a configuration, the flammable gas remaining in the tank chamber 1 can be burned and removed while the vehicle is running by operating as follows.

When each tank chamber 1 shown in FIG. 2 is loaded with a predetermined liquid and transported to a gas station, the bottom valve 2 of each tank chamber 1 is sequentially opened by rotating the operating lever 14, as shown in the figure. unloaded into underground tanks, etc. At this time, flammable gas that has evaporated from the remaining liquid remains in the underground tank.
While introducing this into the tank chamber 1 from a hose (not shown) through the introduction pipe line 4a of the gas pipe 4, the liquid in the tank chamber 1 is discharged to the underground tank. At this time, the manual valve 8 of the inlet pipe 4a and the valve 5 of the tank chamber 1 into which the flammable gas is introduced are opened, while the manual valve 9 of the outlet pipe 4b is closed and the air intake pipe for the flammable gas is opened. 7 is prevented. When unloading is completed, the bottom valve 2 is closed and the tank chamber 1 is filled with flammable gas. The tank truck returns to the loading base with the manual valve 8 closed, but at that time,
The manual valve 9 is opened, and the flammable gas remaining in the tank chamber 1 is gradually combusted by the diesel engine 6. That is, the engine 6 takes in outside air through the air intake pipe 7, purifies it with the air filter 11, and then takes it into the combustion chamber by suction negative pressure during the intake stroke, but at this time, the manual on-off valve 10 is opened. Therefore, the gas remaining in the tank chamber 1 is also sucked in through the gas pipe 4. As a result, the flammable gas is gradually burned in the engine 6, and outside air is introduced into the tank chamber 1 via the safety valve 12 to replenish the amount of flammable gas, thereby reducing the concentration of the retained gas.

By the way, in order to avoid ignition caused by static electricity sparks, it is recommended that the concentration of the accumulated gas in the tank chamber 1 be diluted to 1% or less in the case of gasoline gas and 6% or less in the case of diesel oil. is required in On the other hand, at gas stations etc., tank rooms 1
The concentration and components of the flammable gas introduced into the tank are known in advance. Therefore, in order to burn the flammable gas in the engine 6 and reduce the concentration of gas remaining in the tank chamber 1 to below the above-mentioned explosive concentration by the time it arrives at the loading station, it is necessary to take into account the scheduled travel time. It can be assumed that the valve opening degree should be used. Therefore, a driver or the like adjusts the manual on-off valve 10 to a desired valve opening. In addition, since this valve opening degree is maintained up to the base in principle, the amount of retained gas led out to the engine 6 via the gas pipe 4 is approximately constant, assuming that the engine speed does not change much. Therefore, immediately after leaving the gas station, highly concentrated accumulated gas is discharged. It goes without saying that if there is a concern that knocking may occur when this highly concentrated accumulated gas is supplied to the engine together with air from the air intake pipe 7, the valve opening degree can be appropriately selected to be small. . However, in general, if the planned traveling distance or time is short or the concentration of the introduced flammable gas is high, the valve opening degree of the manual on-off valve 10 will be set to be large. In this way, by the time the tank truck returns to the loading base, the concentration of flammable gas in the tank chamber 1 is reduced, and the flammable gas is combusted by the engine 6, thereby reducing air pollution.

When the tank truck arrives at the loading station, the flammable gas in the tank chamber 1 is diluted to below the explosion limit, or if the traveling time is long or the valve opening is large, the gas is completely replaced with air.
By the way, it is known that when the accumulated gas is gasoline, its flammability is the highest, while when the loaded liquid is light oil or kerosene, its electrostatic property is the highest. Therefore, the risk of explosion is highest when loading diesel oil or kerosene into the tank chamber 1 where gasoline gas is retained. However, even in such a case, static electricity is generated during loading with the loading arm, and even if the amount of charge increases and sparks occur, since the gas concentration of gasoline is below the specified concentration, What happens when it explodes is avoided.

Although the above embodiments have been explained using a diesel engine as an example, the present invention can also be applied to gasoline engines and other engines. Furthermore, it goes without saying that the present invention is applicable not only to tank trucks having three tank chambers but also to all cases having one or more tank chambers and handling one or more types of liquid.

〔Effect of the invention〕

As can be seen from the description of the embodiments above, the present invention has the following features:
The gas piping that discharges the flammable gas accumulated in the tank chamber is connected to the air intake pipe, and a manual on-off valve is inserted in the gas piping, so the engine can burn off the flammable gas before the tank truck arrives at the loading station. can do. Therefore, air pollution due to the release of flammable gas can be avoided, and the tank truck can immediately load liquid without requiring time for gas processing at the loading base, thereby improving its operating efficiency. Of course, even if sparks are generated due to static electricity generated during loading, an explosion within the tank is avoided, ensuring safety during loading operations.

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram of a gas treatment device in a tank lorry according to the present invention, and FIG. 2 is an overall schematic diagram of a tank lorry equipped with the gas treatment device. 1...tank room, 4...gas piping, 6...engine, 7...air intake pipe, 10...manual on-off valve.

Claims (1)

[Claims] 1. A gas pipe for discharging flammable gas accumulated in a tank chamber is connected to an air intake pipe for supplying air to the engine, and the gas pipe is provided with a manual on-off valve for adjusting the amount of flow. By the time the tanker truck reaches the loading base,
A gas processing device for a tank lorry, characterized in that flammable gas in a tank chamber can be combusted by an engine.