JP2762233B2 - Automatic filling method of powder thermal insulation into liquefied gas storage tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquefied gas storage tank,
The present invention relates to a method for filling a large-sized liquefied gas storage tank with powder vacuum insulation with a powder insulation material.

[0002]

2. Description of the Related Art In a large-diameter insulated storage tank such as a liquefied gas storage tank or a liquefied gas storage tank of a tank truck, the outer periphery of an inner tank for storing liquefied gas is covered with an outer tank, and a space between the inner and outer tanks is provided with a powder heat insulating material such as perlite. A vacuum vacuum insulation system is used in which the space between the inner and outer tanks is filled and a vacuum state is maintained. In this case, improper filling of the powder heat insulating material causes poor heat insulation and frost. Further, in the case of perlite, it is known that the packing density affects the heat insulating performance, and good heat insulating performance can be obtained when a capacity of about twice the volume of the filling space is filled.

Conventionally, when filling a large heat insulating storage tank with powdered heat insulating material, the storage tank is placed on a vibrating table or a vibrator is attached to the outer surface of the storage tank so that the powdered heat insulating material is uniformly filled while being vibrated. Was. And in this case,
The opening / closing operation of the filling valve arranged in the supply system of the powder heat insulating material was manually performed.

[0004]

The conventional filling method, in which the storage tank is placed on a vibrating table or a vibrator is attached to the outer surface of the storage tank to apply vibration, has a problem that noise is generated due to the vibration. In addition, there is a problem that the vibration adversely affects the structural components. In addition, when the storage tank is set up, the filling valve is opened and closed at a height of several tens of meters, which causes a problem of poor workability. It is an object of the present invention to provide a method of filling the filling space evenly with the powder heat insulating material without applying vibrations, focusing on such points.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention relates to a storage tank formed by an inner / outer double tank, wherein the space between the inner and outer tanks is connected to a vacuum pump, and the space between the tanks and the powder heat insulating material are connected. The storage container is connected in communication with the powder heat insulating material supply path, the pressurized gas storage container is connected to the space between the tanks by the pressurized gas supply path, and the powder heat insulation material filling valve and the powder heat insulation material are connected to the powder heat insulation supply path.
A photo-tube device that detects the flow of air is arranged, a gas pressurizing valve is arranged in the pressurized gas supply path, and the powder heat insulating material filling valve is opened for a certain period of time, so that the powder heat insulating material is evacuated to the space between the tanks. A powder heat insulating material filling step for supplying for a certain time, and a space between the tanks in which the dry gas stored in the pressurized gas storage container is evacuated by opening a gas pressurizing valve for a certain time after the completion of the powder heat insulating filling step. a powder heat insulator pressure feeding to repeat a predetermined number of times, the powder heat insulator in powder insulation material filling step
A phototube device placed in the supply path stops the flow of the powder insulation.
When detected, close the powder insulation material filling valve and
It is configured to notify that it is in a normal state .

[0006]

According to the present invention, the powder heat insulating material is transferred from the powder heat insulating material storage container to the space between the tanks by opening the powder heat insulating material filling valve disposed in the powder heat insulating material supply path for a certain period of time. Then, by opening the gas pressurizing valve arranged in the pressurized gas supply path for a certain period of time to supply the dry gas in the pressurized gas storage container to the space between the tanks, the powder heat insulating material fed into the space between the tanks is discharged. The bridge and the voids in the powder insulation are crushed by gas pressure. By alternately repeating the supply of the powder heat insulating material and the supply of the pressurized gas several times, the space between the tanks is evenly filled with the powder heat insulating material. In addition, the powder insulation material supply path
There is a phototube device that detects the flow of powder insulation
As a result, there is no powder insulation in the powder insulation storage container.
Or blockage in the powder insulation supply channel
Light indicates that powder heat insulation is not flowing through the heat insulation supply path.
If detected by the tube device, it is determined that the
You will always be informed.

[0007]

1 is a system diagram of a device for filling a liquefied gas storage tank with a powder heat insulating material. This powder insulation material storage device has an inner tank
A liquefied gas storage tank (3) formed into a double tank structure by (1) and an outer tank (2), and a space (4) between the inner and outer tanks of the liquefied gas storage tank (3) is filled. A powder heat insulating material storage container (5) for storing perlite (powder heat insulating material), a pressurized gas storage container (6) for storing a pressurizing gas to be supplied to the inter-chamber space (4), and a pressurized gas storage A pressurizing gas generator (7) for supplying a pressurizing gas to the container (6); and a vacuum pump (8) connected to the inter-chamber space (4) of the liquefied gas storage tank (3). The insulated storage container (5) and the inter-chamber space (4) of the liquefied gas storage tank (3) are connected to each other through a powder heat insulating material supply path (9), and the pressurized gas storage container (6) is connected.
And a space (4) between tanks of the liquefied gas storage tank (3) are connected to each other through a pressurized gas supply path (10), and a pressurized gas generator (7) and a pressurized gas storage container (6) are connected. They are connected by a gas supply path (11).

A gas pressure-operated powder heat-insulating material filling valve (12) is arranged in the powder heat-insulating material supply passage (9), and a gas pressure-actuated gas is supplied to the pressurized gas supply passage (10). A pressure valve (13) is arranged. Gas supply path (11) for both gas pressure operated valves (12) (13)
The working gas passages (14) and (15), which are branched out from the, are connected to each other, and the three-way solenoid valves (16) and (1) are connected to the respective working gas passages (14) and (15).
7) are arranged respectively. Further, a pressurized gas supply source valve (18) and a solenoid valve (19) are arranged in the gas supply path (11).

The pressurizing gas generator (7) includes a liquid nitrogen storage container (20), a vaporizer (21) for vaporizing liquid nitrogen derived from the liquid nitrogen storage container (20), and a vaporizer (21). It comprises an on-off valve (22) and a pressure reducing valve (23) arranged on the outlet path.

A gas injection path (24) is provided from the pressurizing gas generator (7) to the powder heat insulating material storage container (5), and an electromagnetic valve (25) is provided in the gas injection path (24). It is arranged. The solenoid valve (25) operates to open and close the solenoid valve (25) based on the pressure detection of a pressure switch (26) that operates by detecting the internal pressure of the powder heat insulator storage container (5). The inside of (5) is maintained at a slight positive pressure (for example, a gauge pressure of 0.2 kg / cm ² ). That is, the solenoid valve (25) and the pressure switch (26) constitute a pressure control unit (27).

In the figure, reference numeral (28) denotes a pressure transmitter for detecting the pressure of the inter-chamber space (4) in the liquefied gas storage tank (3) and transmitting a signal, and (29) denotes a pressurized gas storage container (6). ) Is a pressure transmitter that detects the internal pressure and transmits a signal, (30) is a pressure gauge that indicates the internal pressure of the pressurized gas storage container (6), and (31) is the powder insulation of the powder insulation supply path (9). It is a photoelectric tube device (pearlite sensor) that detects the flow of material.

Next, a procedure for filling the powder heat insulating material using the powder heat insulating material storage device having the above-described configuration will be described. As shown in FIG. 2, the filling procedure includes a main processing procedure including an operation start processing (A), a pearlite filling processing (B), a pearlite pressurization processing (C), and an operation end processing (D). The process comprises a pressurized gas supply process (E) that operates in parallel with the procedure, and a pearlite supply system abnormality process (F) that operates when an abnormality occurs during the pearlite filling process in the main processing procedure.

Operation start processing (A) and perlite filling processing
(B), as shown in FIG. 3, the operation start processing (A) is completed, the pearlite filling processing (B) and the pressurized gas supply processing described later
(E), and the operation start processing (A)
When the operation switch is operated (Step A1), the counter is reset (Step A2) and the operation switch light is turned on.
(Step A3). The vacuum pump is always operated.

In the perlite filling process (B), it is determined whether or not the pressure in the inter-chamber space (4) of the liquefied gas storage container (3) has become equal to or lower than a set pressure (step B1). When the pressure in the parentheses is equal to or lower than the set pressure, the first timer for setting the filling time of the pearlite starts timing operation (step B2), and the powder heat insulating material filling valve arranged in the powder heat insulating material supply passage (9). The valve (12) is opened (step B3) to supply the powder heat insulating material to the inter-chamber space (4). After a predetermined time (for example, 3 seconds) has elapsed after the opening operation of the powder heat insulating material filling valve (12) (step B4), the photoelectric tube device (31) arranged in the powder heat insulating material supply passage (9) is used. It is determined whether or not the pearlite is flowing normally based on the output (step B5), and the photoelectric tube device (31)
Does not detect a pearlite, the process enters a pearlite supply system abnormality process (F) described later. On the other hand, when the photoelectric tube device (31) detects the pearlite, the second timer is activated (step B6), and then it is determined whether or not the pressure in the inter-chamber space (4) is higher than the set pressure (step B7). , Space between tanks (4)
If the internal pressure is higher than the set pressure, the state is maintained until the set time of the first timer elapses, and after the set time of the first timer elapses, the powder insulation material filling valve (12) is closed. (Step B8) The filling of pearlite is stopped, the pearlite filling process (B) is completed, and the process proceeds to the next pearlite pressurizing process (C).

On the other hand, in step B7, the space between tanks (4)
If the pressure is lower than the set pressure, it is determined whether the set time of the second timer has elapsed (step B10).
If the pressure in the inter-tank space (4) does not increase even after the set time has elapsed, it is determined that the pearlite blockage has occurred in the pearlite supply system, and the pearlite supply system abnormality processing (F) described later
Of the supply system is closed.

Perlite pressurizing treatment (C) and operation end treatment
(D) shows the pearlite filling treatment (B) as shown in FIG.
After the completion of the above, it is determined whether or not the internal pressure of the pressurized gas storage container (6) has increased to a set pressure (for example, a gauge pressure of 2 kg / cm ² ) or more (step C1). When the internal pressure of the gas exceeds the set pressure, the gas pressurizing valve (13) attached to the pressurized gas supply passage (10) is rapidly opened (step C2) and stored in the pressurized gas storage container (6). The pressurizing gas is rapidly injected into the inter-vessel space (4), and the gas pressure of the pressurizing gas crushes the cross-linking of the pearlite powder filled in the inter-vessel space (4) or removes the cavity in the pearlite powder. Crush and compress. At approximately the same time as the opening of the gas pressurizing valve (13), the third timer starts measuring time (step C3), and the pressurizing gas storage container is started.
(6) Judge whether the pressure inside is reduced below the set pressure.
(Step C4) When the internal pressure of the pressurized gas storage container (6) falls below the set pressure, the gas pressurizing valve (13) is closed (Step C5). Then, it is determined whether or not this gas pressurization has been performed a predetermined number of times (step C).
6), gas pressurization is repeated until the set number of gas pressurization operations is completed, and when the set number of gas pressurizations is completed, the counter is updated (step C7), and whether the updated counter number has reached the set number It is determined (step C8) whether or not the updated counter number does not reach the set number, the process returns to step B1 of the pearlite filling process, and the pearlite filling process (B) and the pearlite pressurizing process (C) are repeated.

When the updated counter number reaches the set number, the operation proceeds to an operation end process (D). In the operation end processing (D), after turning on the rotating lamp (step D1), the filling end lamp is turned on (step D2) to notify the worker of the end of filling. Then, when the operator operates the reset button (step D3), the operation switch lamp is turned off (step D4), the filling end lamp is turned off (step D5), and the operation is completed.

On the other hand, if the internal pressure of the pressurized gas storage container 6 does not decrease to the set pressure in step C4 of the pearlite pressurizing process (C), it is determined whether or not the set time of the third timer has been reached. (Step C9) If the gas pressure of the pressurized gas storage container (6) does not drop to the set pressure even after the elapse of the set time of the third timer, the space between tanks (4) is filled with a predetermined amount of perlite. As a result, after the gas pressurizing valve (13) is closed (Step C10), the process proceeds to Step D1 of the operation end processing (D).

The pressurized gas replenishment process (E) operates in parallel with the pearlite filling process (B) and the gas pressurization process (C). As shown in FIG. ) Is determined to be below the set pressure (step E1). If the internal pressure drops below the set pressure, it is determined whether the gas pressurization valve (13) is closed (step E2). If the gas pressurizing valve (13) is in the closed state, the pressurized gas replenishing solenoid valve (19) arranged in the pressurized gas replenishing passage (11) is opened (step E3). Pressurized gas from the pressurized gas generator (7) of the container (6)
(Dry nitrogen gas) is supplied to the space between tanks (4). Then, it is determined whether or not the internal pressure of the pressurized gas storage container (6) has risen above the set pressure (step E4). Solenoid valve for gas supply (1
After the valve closing operation of step 9) is performed (step E5), it is determined whether or not the entire system is stopped (step E6). If it is determined that the operation is not stopped, the process returns to step E1 to form a loop. I do.

Step B5 of the pearlite filling process
If it is determined that the pearlite is not flowing in the powder heat insulating material supply passage (9), the process proceeds to the pearlite supply system abnormality processing (F) shown in FIG. When the pearlite does not flow in the powder heat insulating material supply passage (9), it is considered that the pearlite is cut off in the powder heat insulating material storage container (5) and the pearlite is blocked in the powder heat insulating material supply passage (9). When the perlite is lost in the powder heat insulating material storage container (5), the powder heat insulating material storage container
(5) Since the gas body pressurizing the inside flows into the inter-chamber space (4) without resistance, the pressure of the inter-chamber space (4) becomes higher than the set pressure, whereas the powder heat insulating material supply path If the perlite is blocked in (9), the pressure in the inter-chamber space (4) will be lower than the set pressure, so the inter-chamber pressure is detected to determine whether the supply path is blocked or the perlite is out. It is.

Then, this pearlite supply system abnormality processing
(F), when it is determined in step B4 of the pearlite filling process that pearlite is not flowing in the powder heat insulating material supply passage (9), the second timer starts a time counting operation (step F1),
Next, it is determined whether the internal pressure of the inter-chamber space (4) is higher or lower than the set pressure (Step F2). If the internal pressure of the inter-chamber space (4) is higher than the set pressure, the powder heat insulating material storage container ( As the perlite is cut off in 5), the powder heat insulating material filling valve (12) arranged in the perlite supply passage (9) is closed (step F3), the rotating light is turned on (step F4), and a warning indicating that the perlite is cut off is displayed. The lamp is turned on (step F5). Then, after filling the powder heat insulating material storage container (5) with perlite or replacing the powder heat insulating material storage container (5), the reset button is operated.
(Step F6). When the reset button is operated, the warning light indicating that the pearl light has run out is turned off (step F7), and the apparatus enters a standby state for restart (step F8).

On the other hand, if it is determined in step F2 that the internal pressure of the inter-chamber space (4) is lower than the set pressure, the closed state in the powder heat insulating material supply path (6) is set and the set time of the second timer elapses. It is determined whether or not it has been performed (step F9). When the set time has elapsed, the powder heat insulating material filling valve (12) arranged in the perlite supply path (9) is closed (step F10), and the rotating light is turned on ( In step F11), a warning light indicating the blockage of the perlite supply path is turned on (step F12).

After the pearlite blockage in the powder heat insulating material supply passage (6) is released, the reset button is operated (step F13). When the reset button is operated, the warning light indicating the blockage of the perlite supply path is turned off (step F).
14), and waits for restart (step F1)
5).

In step B7 of the perlite filling process (B), if the pressure in the inter-chamber space (4) does not rise above the set pressure even after the set time of the second timer has elapsed, the process proceeds from step B10. The process proceeds to Step F10 of the direct perlite supply system abnormality process. Then, when restarting, the operation switch is operated (step A).
5), Step A3 of the operation start processing (A) is started, and the pearlite filling processing (B) is advanced again.

In the pearlite filling process having the above-described flow, the pearlite filling operation can be performed fully automatically, so that the pearlite filling can be performed day and night.

In the above-described embodiment, the case where pearlite is used as the powder heat insulating material has been described. However, as the powder heat insulating material, a powder heat insulating material such as a microcell used for powder vacuum heat insulating can be used. Further, as the pressurized gas used for the pressurizing process of the powder heat insulating material, there is no moisture or oil such as nitrogen gas or dry air which is filled in the curl or the like, in addition to the vaporized gas of liquid nitrogen used in the above embodiment. Dry gas can be used. Furthermore, the powder heat insulating material supply path (9)
The gas heat-insulating material filling valve (12) disposed in the gas pressurizing valve (13) and the gas pressurizing valve (13) disposed in the gas pressurizing path (10) may be electrically operated.

[0027]

As described above, according to the present invention, the powder heat insulating material and the dry gas are switched and supplied to the space between the liquefied gas storage tanks sucked by the vacuum pump at regular time intervals, so that the powder is dried. Since the filling operation of the heat insulating material and the pressurizing operation with the dry gas are automatically and repeatedly performed, the space between the tanks can be automatically and uniformly filled with the powder heat insulating material of a predetermined density. This allows the space between the tanks to be filled with the powder heat insulating material during day and night operations.

Further, since gas pressurization is used to fill the powder heat insulating material with a uniform density, it is not necessary to apply vibration to the liquefied gas storage tank. The adverse effects of Furthermore, the opening and closing of the powder insulation material filling valve and gas pressure valve after connecting the powder insulation material supply path and pressurized gas pipe will be performed automatically, so work at heights will be greatly reduced, Safety can be improved.

Further, the powder heat insulating material is supplied to the powder heat insulating material supply passage.
Since a phototube device that detects flow is installed,
Eliminate powder insulation in thermal material storage
Blockage in the powder heat insulating material supply path causes powder heat insulation material supply path
The phototube device detects that the powder insulation is not flowing
Then, it is determined that it is in an abnormal state, and
Therefore, it is important to know at an early stage
And quickly take countermeasures against it
From this, the work of filling the powder insulation can be performed efficiently.
You.

[Brief description of the drawings]

FIG. 1 is a system diagram of a device for filling a liquefied gas storage tank with a powder heat insulating material.

FIG. 2 is a schematic flow chart showing the whole heat insulating material filling procedure.

FIG. 3 is a flowchart of an operation start process and a pearlite filling process.

FIG. 4 is a flowchart of a pearlite pressurizing process and an operation end process.

FIG. 5 is a flowchart of a pressurized gas supply process.

FIG. 6 is a flowchart of a perlite supply system abnormality process.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inner tank, 2 ... Outer tank, 3 ... Liquefied gas storage tank, 4 ... Space between tanks, 5 ... Powder heat insulating material storage container, 6 ... Pressurized gas storage container,
8: vacuum pump, 9: powder heat insulating material supply path, 10: pressurized gas supply path, 12: powder heat insulating material filling valve, 13: gas pressure valve, B ...
Powder insulation material filling step, C ... powder insulation material pressing step.

Continuation of the front page (58) Fields investigated (Int. Cl. ⁶ , DB name) B65B 1/16 B65D 90/06 F16L 59/00 F16L 59/06 3H025 AA01 * AB01 * [B B08 + BB09]

Claims (1)

(57) [Claims] 1. An inner tank (1) for storing liquefied gas and this inner tank
When filling the space between the tanks (4) of the liquefied gas storage tank (3), which has vacuum insulation between the outer tank (2) and the outer tank (2) covering the outer periphery of (1), with the powder interstitial space (4) ) Is connected to the vacuum pump (8) and the space between tanks
(4) The powder heat insulating material storage container (5) and the powder heat insulating material supply path
In addition to the communication connection at (9), the pressurized gas storage container (6) is connected to the space between tanks (4) by the pressurized gas supply path (10), and the powder heat insulation material supply path (9) is filled with the powder heat insulation material. Valve (12) and flow of powder insulation
A photoelectric tube device (31) for detecting movement is arranged , a gas pressurizing valve (13) is arranged in the pressurized gas supply path (10), and a powder heat insulating material filling valve (1
(2) The valve is opened for a certain period of time to supply the powder heat insulating material to the inter-chamber space (4) where the vacuum is drawn, and the powder heat insulating material is filled after the powder heat insulating material filling step (B) is completed. pressurizing valve (13) a powder heat insulator pressurizing step of supplying a dry gas stored in a certain time open to pressurized gas reservoir vessel (6) in a bath between space being evacuated (4) (C ) Is repeated a predetermined number of times, and the powder heat insulating material supply path (9) is filled in the powder heat insulating material filling step (B).
The placed phototube device (31) stops the flow of the powder heat insulating material.
When detected, the powder insulation material filling valve (12) is closed and
Automatic filling of a liquefied gas storage tank with a powdered heat insulating material, which is configured to notify the abnormal condition .