JP3628400B2 - Tank trucks and tank containers - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tank lorry and a tank container (portable container) for containing and transporting an ultra-low temperature liquefied gas according to a high-pressure gas control method such as liquid nitrogen or liquid oxygen.
[0002]
[Prior art]
The tank structure in a tank container (portable container) or a tank lorry for transporting ultra-low temperature liquefied gas usually has a double structure consisting of an inner tank and an outer tank. Further, since the conventional general ultra-low temperature liquefied gas tank container or tank lorry has only one inner tank, only one type of liquefied gas can be transported at a time.
[0003]
[Problems to be solved by the invention]
However, from the viewpoint of improving transport efficiency, there has been a demand for transporting two types of ultra-low temperature liquefied gas at a time.
[0004]
For such a request, a means of arranging two inner tanks in the outer tank can be considered, but the position of the center of gravity depends on the difference in the density or amount of ultra-low temperature liquefied gas filled in each inner tank. There is a problem that fluctuates greatly.
[0005]
In the case of a tank container, since it is often moved up and down by a transport device such as a crane or a forklift, if the position of the center of gravity changes, the transport operation becomes extremely difficult. In the case of a tank lorry, the balance between the front wheels and the rear wheels may be lost, and an overload may occur on the front wheels or the rear wheels.
[0006]
Therefore, an object of the present invention is to provide a tank lorry and a tank container having a double tank structure in which the position of the center of gravity does not fluctuate even when two types of ultra-low temperature liquefied gas are accommodated.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a tank structure of a tank lorry and a tank container according to the present invention includes an outer tub, a first inner tub having the same shape and the same volume, which are juxtaposed in the horizontal direction in the outer tub. Two inner tanks, a third inner tank located in the middle of the first inner tank and the second inner tank in the outer tank, and the bottoms of the first inner tank and the second inner tank And a top connecting pipe that connects upper parts of the first inner tank and the second inner tank, and one ultra-low temperature liquefied gas is supplied to the first inner tank and the second inner tank. The other ultra-low temperature liquefied gas is accommodated in the third inner tank. In order to prevent heat transfer from the outside, it is preferable to provide a heat insulating layer between the outer tank and the first, second and third inner tanks.
[0008]
In such a configuration, since the liquid level height of the ultra-low temperature liquefied gas accommodated in the first and second inner tanks is the same and the liquid amount is also the same, it is determined by the pair of the first and second inner tanks. The position of the center of gravity does not vary in the horizontal direction. In addition, since the third inner tank is arranged between the first and second inner tanks, the horizontal center of gravity position of the third inner tank is the same as the horizontal center of gravity position of the first and second inner tanks. Even if the liquid amount of each ultra-low temperature liquefied gas changes independently or in the same position, the position of the center of gravity of the entire first to third inner tanks hardly fluctuates. Of course, when the center of gravity of the first and second inner tanks and the position of the center of gravity of the third inner tank coincide with each other in the horizontal direction, the center of gravity in the horizontal direction of the first to third inner tanks regardless of the liquid amount or the like. The position is kept constant.
[0009]
In addition, although it is conceivable that the inner tank is divided into three tanks, the internal pressure of each tank becomes very high, so that it is difficult in terms of strength to partition with a flat plate or the like, and it is accommodated. Since the liquid temperature of each ultra-low temperature liquefied gas differs, it is necessary to insulate each tank independently, so that the three inner tanks can be arranged in one outer tank through the heat insulating layer as described above. It is valid.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
[0011]
FIG. 1 shows an ultra-low temperature liquefied gas tank lorry constructed in accordance with the present invention. In FIG. 1, reference numeral 10 denotes a tank truck chassis frame. On the chassis frame 10, a tank 12 for storing two types of ultra-low temperature liquefied gas, for example, liquid oxygen and liquid nitrogen is mounted.
[0012]
The tank 12 has a double structure composed of an outer tank 14 and inner tanks 16, 18, and 20 disposed therein, as in the case of a conventional ultra-low temperature liquefied gas tank. Three inner tanks are provided.
[0013]
The outer tub 14 is a cylindrical container made of, for example, carbon steel (SS41), and is fixed on the chassis frame 10 so that the central axis thereof is substantially horizontal and is directed in the same direction as the front-rear direction of the tank lorry.
[0014]
On the other hand, each of the inner tanks 16, 18, and 20 is a cylindrical container like the outer tank 14, but is a container that directly stores an ultra-low temperature liquefied gas, and therefore has a low temperature strength such as stainless steel (SUS304). Made from. These inner tanks 16, 18, and 20 are arranged substantially coaxially with the outer tank 14, and are arranged in a line along the central axis of the outer tank 14, that is, the front-rear direction of the tank lorry. The front inner tank (first inner tank) 16 and the rear inner tank (second inner tank) 20 have the same shape and the same volume, and the inner tank is located at the center between the inner tanks 16 and 20. (Third inner tank) 18 is arranged. Therefore, the position of the center of gravity determined by the pair of front and rear inner tanks 16 and 20 and the position of the center of gravity of the inner tank 18 in the center are substantially matched in the horizontal direction. Furthermore, in this embodiment, these inner tanks 16, 18 are arranged so that the horizontal center of gravity determined by the three inner tanks 16, 18, 20 as a whole and the horizontal center of gravity of the outer tank 14 substantially coincide. , 20 are arranged in the outer tub 14.
[0015]
These inner tanks 16, 18, and 20 are supported in the outer tank 14 by a known support member (not shown). In addition, a heat insulating layer 21 is provided in the space between the outer tub 14 and the inner tubs 16, 18, 20 and in the space between the adjacent inner tubs 16, 18; As the heat insulating layer 21, a pearlite vacuum heat insulating structure in which the space is evacuated and filled with a heat insulating material such as pearlite is effective, but depending on the type of liquefied gas to be accommodated, a laminated vacuum heat insulating structure is used. Further, a urethane foam heat insulating structure, a pearlite heat insulating structure, or the like may be employed.
[0016]
The inner tanks 16 and 20 on the front side and the rear side are filled with one of two types of ultra-low temperature liquefied gases, and the bottom parts and the upper parts of the inner tanks 16 and 20 are the bottom connection pipe 22 and the upper connection pipe 24, respectively. It is connected by. Thereby, the liquid level of the ultra-low temperature liquefied gas with which the inner tanks 16 and 20 were filled always becomes the same height. The other ultra-low temperature liquefied gas is filled in the central inner tank 18.
[0017]
The ultra-low temperature liquefied gas is charged into and discharged from the front and rear inner tanks 16 and 20 and the central inner tank 18 in the first operation unit 26 and the second operation unit ( (Not shown). The first operation unit 26 is for the inner tanks 16 and 20, and the second operation unit is for the inner tank 18. Since these operation units have the same configuration, only the first operation unit 26 will be described.
[0018]
The first operation unit 26 is a so-called pressurizing type, and basically has an upper filling pipe 28 connected to the upper part of the inner tank 20 on the rear side, and a bottom filling / filling connected to the bottom of the inner tank 20. The discharge pipe 30 is composed of a pressure pipe 34 extending in a loop shape from the bottom to the top of the inner tank 20 and having a pressure evaporator 32 interposed therebetween. The upper filling pipe 28 and the bottom filling / discharge pipe 30 are connected to a common filling / discharge nozzle 36, and the ultra-low temperature liquefied gas is taken in and out from the nozzle 36. The pressurizing pipe 34 is connected to a discharge pipe 38 for releasing the gas in the inner tank 20 into the atmosphere. Reference numeral 40 denotes a vent pipe 40, reference numerals 42 and 44 denote pressure / liquid level measuring pipes, reference numeral 46 denotes a pressure gauge, and reference numeral 48 denotes a liquid level gauge.
[0019]
When the ultra-low temperature liquefied gas is filled using such an operation unit 26, the valve 50 of the upper filling pipe 28 is opened, and the ultra-low temperature liquefied gas is introduced into the inner tank 20 from the filling / discharge nozzle 36 through the upper filling pipe 28. . If necessary, the valve 52 is opened to perform filling from the bottom filling / discharge pipe 30. At this time, if the gas pressure in the inner tank 20 rises, the valve 54 in the discharge pipe 38 is opened to release the gas. When discharging the ultra-low temperature liquefied gas, the valves 56 and 58 in the pressurizing pipe 34 are opened, the ultra-low temperature liquefied gas is vaporized through the pressurized evaporator 32, and the vaporized gas is returned to the inner tank 20 to return to the inner tank 20. Increase the pressure inside. Then, the valve 52 is opened, and the ultra-low temperature liquefied gas is discharged from the nozzle 36 through the bottom filling / discharging pipe 30 by using the pressure in the inner tank 20 as a driving force.
[0020]
Thus, when the ultra-low temperature liquefied gas is taken in and out from the rear inner tank 20, the front inner tank 16 communicates with the rear inner tank 20 by the bottom connecting pipe 22 and the upper connecting pipe 24. The ultra-low temperature liquefied gas enters and exits the inner tank 16 and its liquid level also fluctuates at the same height as the liquid level of the rear inner tank 20. Since the inner tank 16 on the front side and the inner tank 20 on the rear side have the same shape and the same volume, if the liquid level is the same, the amount of liquid inside is also the same. Therefore, the positions of the center of gravity of the two front and rear inner tanks 16 and 20 do not fluctuate in the horizontal direction by taking in and out the ultra-low temperature liquefied gas.
[0021]
On the other hand, other ultra-low temperature liquefied gas is filled or discharged from the central inner tank 18 by the second operation unit. In this case, it goes without saying that the horizontal center of gravity position of the inner tank 18 does not change. .
[0022]
Therefore, in this embodiment, the center of gravity of the central inner tank 18 and the center of gravity of the front and rear inner tanks 16 and 20 are aligned in the horizontal direction, so that each cryogenic liquefied gas is charged or discharged separately. However, the position of the center of gravity determined by the three inner tanks 16, 18, and 20 does not vary in the horizontal direction. Furthermore, in the present embodiment, the center of gravity of the outer tub 14 is also matched with the position of the center of gravity of the entire inner tub 16, 18, 20. As described above, the position of the center of gravity of the tank 12 containing the two types of ultra-low temperature liquefied gas is kept constant in the horizontal direction without considering the difference in filling amount and density, so that the vehicle balance of the tank lorry is suitably maintained. Will be.
[0023]
As mentioned above, although preferred embodiment of this invention was described in detail, it cannot be overemphasized that this invention is not limited to the said embodiment. For example, in the above embodiment, the center of gravity of the front and rear inner tanks 16 and 20 and the center of gravity of the center inner tank 18 are matched, but it is not necessary to accurately match the positions of the center of gravity. This is because if the inner tank 18 is arranged between the front and rear inner tanks 16 and 20, the deviation of the center of gravity position is slight, and even if the position of the center of gravity fluctuates, it is within an allowable range in the carrying work. For the same reason, it is not necessary to accurately match the position of the center of gravity of the outer tub 14 with the position of the center of gravity of the inner tubs 16, 18, and 20. Further, the type of the operation unit connected to the tank 12 is not limited to the pressurizing type, and various types such as a type of discharging using a pump are conceivable.
[0024]
Further, the structure of the tank 12 is not different from the tank structure in the ultra-low temperature liquefied gas tank container. Therefore, those skilled in the art will easily understand that the present invention can be applied to the tank container.
[0025]
【The invention's effect】
As described above, according to the present invention, when two types of ultra-low temperature liquefied gas are accommodated, the position of the center of gravity in the horizontal direction of the tank is kept almost constant regardless of the difference in density or the change in the amount of liquid in the inner tank. . Therefore, when transporting with a tank lorry or a tank container according to the present invention, the load balance is not lost, and two types of ultra-low temperature liquefied gas can be transported safely at one time. This makes it possible to improve the efficiency of transportation work and reduce costs.
[Brief description of the drawings]
FIG. 1 is an explanatory view schematically showing a tank lorry according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Chassis frame, 12 ... Tank, 14 ... Outer tank, 16 ... Inner tank (1st inner tank), 18 ... Inner tank (3rd inner tank), 20 ... Inner tank (2nd inner tank), 21 ... heat insulation layer, 22 ... bottom connection pipe, 24 ... top connection pipe, 26 ... operation unit.

Claims (6)

A tank lorry having a tank containing two types of ultra-low temperature liquefied gas,
An outer tank,
A first inner tank and a second inner tank having the same shape and the same volume, juxtaposed horizontally in the outer tank;
A third inner tank disposed in the outer tank and intermediate the first inner tank and the second inner tank;
A bottom connecting pipe that connects bottoms of the first inner tank and the second inner tank;
An upper connecting pipe for connecting upper portions of the first inner tank and the second inner tank;
A tank lorry characterized in that one ultra-low temperature liquefied gas is accommodated in the first inner tank and the second inner tank, and the other ultra-low temperature liquefied gas is accommodated in the third inner tank. . The first, second and third centroid positions determined by the pair of the first inner tub and the second inner tub and the centroid positions of the third inner tub substantially coincide with each other in the horizontal direction. The tank lorry according to claim 1, wherein an inner tank is disposed. The tank lorry according to claim 1 or 2, wherein a heat insulating layer is provided between the outer tub and the first, second and third inner tubs. A tank container containing two types of ultra-low temperature liquefied gas,
An outer tank,
A first inner tank and a second inner tank having the same shape and the same volume, juxtaposed horizontally in the outer tank;
A third inner tank disposed in the outer tank and intermediate the first inner tank and the second inner tank;
A bottom connecting pipe that connects bottoms of the first inner tank and the second inner tank;
An upper connecting pipe for connecting upper portions of the first inner tank and the second inner tank;
A tank in which one ultra-low temperature liquefied gas is accommodated in the first inner tank and the second inner tank, and the other ultra-low temperature liquefied gas is accommodated in the third inner tank. container. The first, second and third centroid positions determined by the pair of the first inner tub and the second inner tub and the centroid positions of the third inner tub substantially coincide with each other in the horizontal direction. The tank container according to claim 4, wherein an inner tank is disposed. The tank container according to claim 4 or 5, wherein a heat insulating layer is provided between the outer tub and the first, second and third inner tubs.

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