JPH084981A - Method of device for charging granular heat-insulating material into heat-insulating space - Google Patents

Abstract

PURPOSE:To provide a method of and a device for charging a granular heat- insulator in a heat-insulating space such as a vacuumed heat-insulating storage tank, with which the granular heat-insulator such as perlite can be easily charged into the heat-insulating space and the heat-insulating space can be evacuated in a short time after the charge of the heat-insulator. CONSTITUTION:A granular heat-insulting material is introduced in a hopper 11, and heating and drying air is fed into the hopper 11 from an air pipe 12 so as to dry the granular material. Thereafter, the heat-insulating space 15 such as a vacuumed heat-insulating storage 14 is evacuated by a vacuum pump 26 while the granular material is fed and charged int the space 15 through a conveying pipe 16 opened to the bottom part of the hopper 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for filling a heat insulating space with a granular heat insulating material, and more particularly to a heat insulating space for filling a heat insulating space such as a vacuum heat insulating storage tank for storing a low temperature liquefied gas with the granular heat insulating material. TECHNICAL FIELD The present invention relates to a method and a device for filling a granular heat insulating material into a container.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, when filling a heat insulating space 2 of a vacuum heat insulating storage tank 1 for storing low temperature liquefied gas with perlite which is a granular heat insulating material, a perlite filling port 3 of the storage tank 1 is filled. And a bag 4 containing pearlite are connected by a hose 5, and the pearlite in the bag 4 is sucked by using the negative pressure of the heat insulating space 2 while drawing a vacuum in the heat insulating space 2 with a vacuum pump 6. Was there. At this time, when the pearlite in the bag 4 is exhausted, the bag is replaced with a new bag containing pearlite.

[0003]

However, in the above conventional filling method, the vacuum heat insulating storage tank 1 is filled before the pearlite is filled.
Since the heat-insulating space 2 of the storage tank 1 is in contact with the atmosphere, there is wetness between the inner and outer tanks of the storage tank 1 due to rust or the like, and the atmosphere permeates from the paper, polyethylene, etc. that make up the bag 4 for containing perlite. Perlite gets wet over time,
Since the humid atmosphere is sucked into the heat insulating space 2 when the bag is replaced, it takes a lot of days until the heat insulating space 2 of the storage tank 1 reaches a predetermined degree of vacuum after the pearlite is filled.

In view of the above, the present invention provides a heat insulating space in which a heat insulating space such as a vacuum heat insulating storage tank can be easily filled with granular heat insulating material such as pearlite, and the heat insulating space after filling the heat insulating material can be evacuated in a short time. It is an object of the present invention to provide a method and apparatus for filling the granular heat insulating material.

[0005]

In order to achieve the above-mentioned object, the method for filling granular heat insulating material in the heat insulating space of the present invention comprises:
After the granular heat insulating material is put into the hopper and heated dry air is fed into the hopper to dry the granular heat insulating material, the heat insulating space such as the vacuum heat insulating storage tank is kept in vacuum from the hopper to the heat insulating space. It is characterized in that the granular heat insulating material is fed and filled. Further, it is characterized in that dry air is previously fed into the hopper or the heat insulating space to be dried before being filled with the granular heat insulating material.

Further, the granular heat insulating material filling apparatus of the present invention is
A hopper for holding the granular heat insulating material, an air pipe for feeding heated dry air into the hopper, and an air diffuser pipe connected to the air pipe for ejecting dry air into the hopper,
Insulating material conveying pipe that communicates with the vicinity of the bottom of the hopper and an insulating space such as a vacuum insulating storage tank to introduce the granular insulating material into the insulating space from within the hopper, and the upper space of the hopper and the insulating material conveying pipe. An air supply pipe that communicates with the opening in the hopper, that is, the vicinity of the suction port, and sends the heated dry air in the upper space of the hopper to the heat insulating material transfer pipe, and communicates with the upper space of the hopper and the heat insulating space. And ventilation pipes for feeding heated dry air in the upper space of the hopper into the heat insulating space.

[0007]

[Operation] According to the method of the above configuration, after the granular heat insulating material is put into the hopper, heated dry air is sent to dry the granular heat insulating material, so that the moisture of the granular heat insulating material can be removed. Further, while keeping the heat insulation space of the low temperature liquefied gas storage tank in vacuum, since the granular heat insulation material in the hopper is conveyed and filled into the heat insulation space due to the pressure difference, there is no mixing of outside air containing moisture into the heat insulation space, It is possible to shorten the time required to evacuate the heat insulating space after filling the granular heat insulating material. In particular, by drying the hopper and the heat insulating space in advance, the time for drying the granular heat insulating material in the hopper and the time for vacuuming the heat insulating space can be further shortened.

Further, in the apparatus having the above-mentioned structure, the granular heat insulating material in the hopper can be heated and dried substantially uniformly by the air diffuser connected to the air pipe. Furthermore, since a heat insulating material transfer pipe that guides the granular heat insulating material to the heat insulating space of the vacuum heat insulating storage tank is provided near the bottom of the hopper, the suction port of the transfer pipe can be used when filling the heat insulating space while vacuuming the heat insulating space. It is possible to efficiently inhale the granular heat insulating material guided to.

Moreover, when the granular heat insulating material is filled in the heat insulating space, the heated dry air in the upper space of the hopper is sucked into the vicinity of the opening (suction port) of the heat insulating material conveying pipe by the air supply pipe. It is possible to reduce the density of the granular heat insulating material flowing therein, smooth the flow of the granular heat insulating material, and prevent clogging of the granular heat insulating material in the pipe.

Further, since the pipe for feeding the heated dry air in the upper part of the hopper is provided to the heat insulating space, when the granular heat insulating material is filled in the heat insulating space, the heated dry air is appropriately fed from the pipe to the heat insulating space. By vacuum breaking the heat insulating space, it is possible to increase the packing density of the granular heat insulating material by giving a shock to the heat insulating space due to a pressure change.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in more detail based on an embodiment of the device of the present invention shown in the drawings. The apparatus for filling the granular heat insulating material shown in FIG. 1 includes a hopper 11 for holding a predetermined amount of the granular heat insulating material, for example, pearlite, an air pipe 12 for feeding heated dry air into the hopper 11, and an air pipe 12. An air diffuser pipe 13 that is continuously provided and blows dry air into the hopper 11, and a heat insulating material conveying pipe 16 that has one end opening near the bottom of the hopper 11 and the other end communicating with the heat insulating space 15 of the vacuum heat insulating storage tank 14. And an air supply pipe 17 that communicates the upper space of the hopper 11 with the vicinity of the suction port 16a in the hopper 11 of the heat insulating material conveying pipe 16, and communicates with the upper space of the hopper 11 and the heat insulating space 15. The ventilation pipe 18 is provided.

A pearlite inlet 19 and an exhaust pipe 20 are provided on the upper surface of the hopper 11, and the balloon 2 for storing the heated dry air introduced into the hopper 11 is provided.
1 is provided. Further, the hopper 11 is provided with a dew point meter 22 for measuring the dew point of the internal air and thermometers 23a, 23b for measuring the temperature.

The air pipe 12 is provided with a dryer (not shown) for removing water in the air and a hot air generator 24 for heating the air to a predetermined temperature. This air pipe 12
The air diffuser 13 connected to the air diffuser 13 is capable of ejecting the heated dry air evenly into the hopper 11, and is formed so as not to cause a non-uniform flow of the heated dry air. Has a horizontal outer pipe portion 13a along the vicinity of the inner peripheral wall of the hopper 11, and a vertical inner pipe portion 13b arranged on the central axis of the hopper 11,
The outer pipe portion 13a and the inner pipe portion 13b have a large number of air diffuser holes 13
c is provided. In addition, it is preferable to wind a fine mesh, glass wool, or the like around the outer circumference of the air diffuser 13 so that pearlite does not enter the tube.

Valves 16b, 17a and 18 are provided in the heat insulating material conveying pipe 16, the air feeding pipe 17 and the ventilation pipe 18, respectively.
a is provided, the heat insulating material conveying pipe 16 and the ventilation pipe 1
8 is joined and connected to the pearlite filling port 25 of the vacuum heat insulating storage tank 14. A vacuum pump 26 and a vacuum gauge 27 are provided in the heat insulating space 15 of the vacuum heat insulating storage tank 14.

Next, the procedure for filling pearlite into the heat insulating space 15 of the vacuum heat insulating storage tank 14 using the above-described filling device will be described. First, after closing each valve, a predetermined amount of perlite is supplied from the perlite inlet 19 to the hopper 11.
Throw in. The amount of pearlite charged is set to be slightly larger than the predetermined amount of filling so that the diffuser tube 13 is hidden.

Next, after closing the pearlite inlet 19 and opening the exhaust valve 20a of the exhaust pipe 20, dry air from a dry air source (not shown) is introduced from the air pipe 12 and the hot air generator 24 is used. The temperature is raised to a predetermined temperature and fed into the air diffuser 13. The heated dry air ejected from the air diffuser 13 into the hopper 11 heats and dries the perlite, and then the exhaust pipe 2
It is discharged from 0 to the outside. Further, the valve 22a of the dew point meter 22
To open the air in the hopper upper space to the dew point meter 22 and finish the heating and drying of the perlite when the dew point becomes equal to or lower than a predetermined value, but before the end, close the exhaust valve 20a and close the balloon 21. The dry air is stored in, and when a predetermined amount of dry air is stored in the balloon 21, the introduction of the dry air from the air pipe 12 is stopped, and the valve 22a of the dew point meter 22 is also closed.

On the other hand, in parallel with the heating and drying of the perlite, the heat insulating space 15 of the vacuum heat insulating storage tank 14 is evacuated to the vacuum pump 26.
While the vacuum is applied, the dry air introduced from the dry air source through another pipe (not shown) is flowed for a predetermined time to dry the heat insulating space 15. Since the drying of the heat insulating space 15 is shorter than the heat drying of the perlite, the drying operation of the heat insulating space 15 may be finished before the heat drying of the perlite is finished.

Next, while continuing to evacuate the heat insulating space 15, the valve 16b of the heat insulating material conveying pipe 16 is opened and the perlite in the hopper 11 is fed into the heat insulating space 15 due to the pressure difference. At this time, the valve 17a of the air supply pipe 17 is opened by a predetermined amount, and the dry air in the hopper upper space is introduced by the air supply pipe 17 into the vicinity of the suction port 16a of the heat insulating material transfer pipe 16. As a result, dry air is mixed into the perlite sucked from the suction port 16a, the density of the perlite per unit volume becomes low, the flow of the perlite is made smooth, and the perlite is prevented from being clogged in the heat insulating material conveying pipe 16. You can

Further, since the perlite in the hopper 11 falls due to its own weight to the bottom of the hopper 11, that is, in the vicinity of the suction port 16a of the heat insulating material conveying pipe 16, substantially the entire amount of the perlite in the hopper 11 is continuously insulated. It can be fed and filled into the space 15.

Further, during the above filling operation, the air in the hopper 11 is also sucked together with the perlite from the heat insulating material conveying pipe 16 into the heat insulating space 15, so that the pressure in the hopper 11 drops, but it is stored in the balloon 21. Drying air flowing into the hopper 11 prevents pressure drop in the hopper 11.

When the filling of pearlite into the heat insulating space 15 progresses to a certain extent, the valve (vacuum breaking valve) 1 of the ventilation pipe 18
8a is opened and closed to insulate the dry air in the hopper 11 into the heat insulating space 1
5, the heat insulating space 15 is given an impact due to a pressure change to sink the perlite, whereby the packing density of the perlite in the heat insulating space 15 can be increased. By appropriately repeating the opening / closing operation of the valve 18a of the ventilation pipe 18, the entire heat insulating space 15 can be filled with pearlite at a high density.

After the insulating space 15 is filled with a predetermined amount of pearlite as described above, the pearlite filling port 25 of the vacuum insulating storage tank 14 is closed while the vacuum pump 26 continues to operate, and the inside of the insulating space 15 is filled with a predetermined vacuum. Every time.

By thus filling the heat insulating space 15 of the vacuum heat insulating storage tank 14 with perlite (granular heat insulating material), the perlite filling operation can be performed in a state where the outside air containing moisture is shut off. The number of days of vacuum evacuation after the filling until the heat insulating space 15 reaches a predetermined vacuum degree can be significantly shortened as compared with the conventional case.

The structure of the filling device is not limited to the above-mentioned embodiment, and for example, the air diffuser 13 is formed in any shape as long as heated dry air can be sufficiently supplied to the granular heat insulating material in the hopper 11. It can be provided not only in the horizontal and vertical directions but also in an oblique direction, and the shape can be arbitrary such as a ring shape and a radial shape, and it may be branched into a plurality, and the number thereof is also arbitrary, and the size of the hopper 11 is large. The optimum shape may be selected according to the conditions such as the amount of granular heat insulating material retained. Further, the number and size of the air diffuser holes 13c, the jetting direction, and the like are arbitrary, and may be set so that the heated dry air does not cause a pressure drop.

Further, the suction port 16a of the heat insulating material conveying pipe 16
The introduction of dry air into the vicinity may be performed by using dry air from another dry air source in addition to the dry air in the upper space of the hopper by the air supply pipe 17. Furthermore, the heat insulation space 15
The pressure drop in the hopper 11 during the filling of the granular heat insulating material can also be performed by introducing the dry air from the dry air source into the hopper 11 without providing the balloon 21.

On the other hand, before performing the filling operation of the granular heat insulating material, that is, before charging the granular heat insulating material into the hopper 11, heated dry air is introduced from the air pipe 12 to dry the inside of the hopper 11. By setting it, it is possible to shorten the time required for drying the granular heat insulating material, and as described above, by performing the drying operation of the heat insulating space 15, the number of days of evacuation after filling the granular heat insulating material is further shortened. it can. It is also possible to use heated dry air in the hopper 11 as the gas for the drying operation of the heat insulating space 15.

When there are a plurality of vacuum heat insulating storage tanks to be filled with the granular heat insulating material, a hopper having a large capacity is used,
By appropriately branching the heat-insulating material-conveying pipe or the like, it is possible to continuously or simultaneously fill the heat-insulating spaces of the plurality of vacuum heat-insulating storage tanks with pearlite.

Experimental Example Using the filling device having the structure shown in FIG. 1, pearlite was filled in the heat insulating space of the vacuum heat insulating storage tank having an inner volume of 2800 liters. The capacity of the hopper 11 can hold more perlite than the amount filled in the heat insulating space, and the air diffuser 1
In No. 3, 96 air diffuser holes 13c having a diameter of 12 mm were opened vertically and laterally at regular intervals by 90 °. Further, glass wool was wrapped around the air diffuser 13 and fixed with a wire so that pearlite did not enter the tube through the air diffuser 13c.

First, dry air having a dew point of -25 ° C. is heated to 200 ° C. by the heater of the hot air generator 24, and the air pipe 1
It was fed into the hopper 11 from No. 2 through the air diffuser 13, and the hopper main body was heated for 24 hours to dry the inside. Next, a predetermined amount of perlite was introduced into the hopper 11 from the perlite inlet 19 and the heated dry air was introduced for 48 hours to heat and dry the perlite.

On the other hand, the heat insulating space 15 of the vacuum heat insulating storage tank 14
Dried the air for 15 minutes while operating the vacuum pump 26 to dry the heat insulating space 15.

Then, while the heat insulating space 15 was evacuated, the valve 16b of the heat insulating material conveying pipe 16 was opened, and the valve 17a of the air feeding pipe 17 was slightly opened.

When a certain amount of perlite is filled in the heat insulating space 15, the valve 18a of the ventilation pipe 18 is opened and closed to give a shock of a pressure change to the heat insulating space 15, and this operation is repeated 5 times to sink the perlite. .

After the filling of a predetermined amount of pearlite was completed, the pearlite filling port 25 was closed, and the heat insulating space 15 was evacuated by the vacuum pump 26 to a vacuum degree of 1 × 10 ^-1 Torr which is a passing acceptance standard. The number of days required for this evacuation was 8 days.

For comparison, the vacuum heat insulating storage tank 14 was left in the atmosphere for 2 days and filled with pearlite by the conventional method. As a result, it took 25 days to evacuate before the degree of vacuum reached 1 × 10 ⁻¹ Torr, which is the acceptance criteria for shipment.

[0035]

As described above, according to the method for filling the heat insulating space with the granular heat insulating material of the present invention, the granular heat insulating material is dried by heated dry air, and then the granular heat insulating material is changed by the difference in the degree of vacuum. Since it is transferred and filled into the heat-insulated space of the vacuum heat-insulated storage tank, dry perlite can be filled into the heat-insulated space without mixing the outside air containing moisture (humidity), and the evacuation to reach the predetermined vacuum degree can be performed. The number of days required can be greatly reduced.

Further, by drying the hopper and the heat insulating space in advance, it is possible to further shorten the time for drying the granular heat insulating material in the hopper and the time for vacuuming the heat insulating space. Further, the filling device for the granular heat insulating material can heat and dry the granular heat insulating material in the hopper substantially uniformly by the air diffuser provided in the hopper. Further, by feeding dry air into the heat insulating material conveying pipe through the air supply pipe, it is possible to prevent the granular heat insulating material from being clogged in the pipe and smoothly fill the granular heat insulating material. Moreover, since the ventilation pipe for feeding the dry air in the hopper into the heat insulating space is provided, the dry air is intermittently fed from the pipe into the heat insulating space to give an impact due to pressure fluctuation in the heat insulating space. It is possible to densely fill the granular heat insulating material.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the device of the present invention.

FIG. 2 is a plan view of an air diffuser.

FIG. 3 is an explanatory diagram showing an example of a conventional filling operation of a granular heat insulating material.

[Explanation of symbols]

11 ... Hopper, 12 ... Air piping, 13 ... Air diffuser, 14
... Vacuum insulation storage tank, 15 ... Insulation space, 16 ... Insulation material transfer pipe, 17 ... Air supply pipe, 18 ... Ventilation pipe, 19 ... Perlite inlet, 20 ... Exhaust pipe, 21 ... Balloon, 22 ... Dew point meter, 24 ... Hot air generator, 25 ... Perlite filling port, 26
…Vacuum pump

Continuation of the front page (72) Inventor Makoto Hayakawa 6-2 Kojima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Oxygen Co., Ltd.

Claims (4)

[Claims] 1. When filling a granular heat insulating material into a heat insulating space such as a vacuum heat insulating storage tank, the granular heat insulating material is put into a hopper, and heated dry air is fed into the hopper so as to remove the granular heat insulating material. After being dried, the granular heat insulating material is fed and filled into the heat insulating space from the hopper while the vacuum is kept in the heat insulating space. 2. The granular thermal insulation material according to claim 1, wherein the hopper feeds dry air into the hopper to dry the granular thermal insulation material before the granular thermal insulation material is charged. Filling method. 3. The granular heat insulation to the heat insulation space according to claim 1, wherein the heat insulation space is preliminarily filled with dry air by being fed with dry air before being filled with the granular heat insulation material. Material filling method. 4. An apparatus for filling a granular heat insulating material in a heat insulating space of a vacuum heat insulating storage tank, the hopper holding the granular heat insulating material, an air pipe for feeding heated dry air into the hopper, An air diffuser that is connected to an air pipe and blows dry air into the hopper, and a heat insulating material that communicates with the heat insulating space near the bottom of the hopper and introduces the granular heat insulating material from the hopper into the heat insulating space. A transfer pipe, an air supply pipe that communicates with the upper space of the hopper and the vicinity of the opening in the hopper of the heat insulating material transfer pipe, and sends the heated dry air of the hopper upper space into the heat insulating material transfer pipe, An apparatus for filling granular heat insulating material into a heat insulating space, comprising: a ventilation pipe that communicates with an upper space of a hopper and the heat insulating space and sends heated dry air in the upper space of the hopper into the heat insulating space. .