JPH056079B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides a method for recovering liquid remaining in piping.

[Conventional technology]

For example, in the process of transferring liquid from the main tank to the recovery tank via piping, if the liquid to be transferred is expensive, such as unprocessed liquor or medicinal liquid, it is necessary to recover the liquid remaining in the piping.

For this reason, the recovery method shown in FIGS. 4 to 6 has conventionally been adopted.

The first method is as shown in FIG.
and recovery tank 2 are connected by a pipe 5 via valves 3 and 4 provided near both tanks 1 and 2, and this pipe 5
A waste liquid valve 6 is provided at the lowest part 5a of the liquid, so that the liquid can be collected by gravity flow.

The second method, as shown in FIG. The liquid 9 is used to push the remaining liquid 10.

The third method is shown in FIG. 6, in which a pig or hair ball insertion pipe 12 is connected to the pipe 5 through a valve 11 in the vicinity of the valve 3 near the main tank, and a pig or hair ball insertion pipe 12 is connected to the pipe 12 through a valve 13. Connect the nitrogen gas pressure feed pipe 14 to the insertion pipe 12, and insert a pig or hair ball 15 into the insertion pipe 12.
nitrogen gas is fed through a nitrogen gas pressure feeding pipe 14, and the remaining liquid 10 is fed under pressure using a pig or hair ball 15.

[Problem that the invention seeks to solve]

However, in the case of the first method, if there is a trap part 5b in the piping 5, it cannot be completely recovered, and in the case of the second method, water etc. may get mixed in with the residual liquid, or the residual liquid in the piping after collection cannot be completely recovered. Cooling becomes a problem, and in the case of the third method, there is a risk that foreign matter will get mixed into the residual liquid because the pigs and hair balls rub against the pipe wall surface.

Therefore, an object of the present invention is to reduce costs and prevent quality deterioration by recovering expensive liquid using residual liquid.

[Structure of the invention]

In order to achieve the above object, the present invention has a first aspect of the present invention, which involves freezing a portion of the remaining liquid in the piping to produce ice cubes, and pressurizing the ice cubes with an inert gas such as nitrogen to remove the residual liquid in the piping. The second invention is characterized in that the liquid is collected by pushing it with an ice block, and the second invention is characterized in that a liquid that is the same as or has the same properties as the remaining liquid in the pipe is frozen to produce an ice block, and this ice block is inserted into the pipe. The system is characterized in that it is pressurized with an inert gas such as nitrogen, and the remaining liquid in the pipe is recovered by pushing it with an ice block.

〔Example〕

The illustrated embodiment will be described below.

1 and 2 illustrate an embodiment of the first invention, in which a main tank 21 and a recovery tank 22 are connected by a pipe 25 via valves 23 and 24. The piping 25' of the piping 25' in the vicinity of the main tank 21 and close to the valve 23 is made of a material that is not brittle at low temperatures.
A liquid tank 26 containing liquid nitrogen or the like is attached to this part. Further, a pressurized gas insertion pipe 28 is connected to the pipe 25 between the valve 23 and the liquid tank 26 via a valve 27 .

Then, when the valves 23 and 24 are opened to transfer the liquid 29 from the main tank 21 to the recovery tank 22, the valve 23 is closed and a cryogenic liquefied gas 30 such as liquid nitrogen is put into the liquid tank 26. is used as a refrigerant to freeze a portion of the liquid 29 remaining in the pipe 25 to produce residual ice blocks 29'. Next, the cryogenic liquefied gas 30 is removed from the liquid tank 26, heated naturally by the atmosphere or poured hot water etc. into the liquid tank 26 to melt the frozen contact area on the inner wall of the ice block piping 25', and the valve 27 is opened. Inert gas such as nitrogen gas is fed from the pressurized gas feed pipe 28.

By supplying this inert gas, the residual ice block 29'
The residual liquid 29 is pumped and pushed, and the residual liquid 29 is collected in the recovery tank 22. The residual liquid ice blocks 29' are also naturally thawed in the recovery tank 22, etc., and the remaining liquid 29 in the pipe 25 is recovered. can.

Next, an embodiment of the second invention will be explained with reference to FIG. 3. The main tank 31 and the recovery tank 32 are
3 and 34, and are connected by a pipe 35.
An ice block insertion tube 37 is connected to the vicinity of the valve 33 via a valve 36, a lid 38 is provided at the insertion port of the tube 37, and a pressurized gas feed tube 40 is connected to the tube 37 via a valve 39.

When the liquid 41 is completely transferred from the main tank 31 to the recovery tank 32, the valve 34 is closed and the lid 38 is closed.
Then, insert a ball-shaped ice block 41' made of a liquid that is the same as the liquid 41 or has the same properties into the ice block insertion tube 3.
7, close the lid 38, open the valve 36 and 39, and feed inert gas from the pressurized gas feed pipe 40.

As a result, the ice block 41' is force-fed through the pipe 35, pushes the remaining liquid 41' in the pipe 35, and
is collected in the collection tank 32, and the ice blocks 41' are also collected in the collection tank 32 and naturally thaw.

Further, a discharge pipe 43 is connected to the vicinity of the valve 34 of the pipe 35 via a valve 42, the valve 42 is opened, the valve 34 is closed, and the residual liquid 41 and ice blocks 41' are discharged from the discharge pipe 43.
can also be collected separately.

In the above two embodiments, the ice cubes are not limited to those that are completely frozen, but may also be a collection of multiple ice cubes or a shear bed type. The remaining liquid can be easily recovered even if the liquid is removed.

〔Effect of the invention〕

As described above, the present invention recovers the residual liquid in the piping by pumping ice cubes that are the same as or have the same properties as the residual liquid in the piping using an inert gas, so there is no deterioration in quality and even if there are traps, it can be pushed out. It can be recovered, the recovery rate is improved, and the inside of the piping is not contaminated.

[Brief explanation of the drawing]

Figure 1 is a piping diagram for explaining an embodiment of the first invention, Figure 2 is an enlarged view of the main part of Figure 1, and Figure 3 is a piping diagram for explaining an embodiment of the second invention. , FIG. 4 to FIG. 6 are piping diagrams for explaining each other example of the conventional residual liquid processing method. 21, 31... main tank, 22, 32... collection tank, 23, 24, 33, 34... valve, 25,
35... Piping, 26... Liquid tank, 28, 40... Pressurized gas feed pipe, 37... Ice block feed pipe, 29, 41
...Liquid, 29', 41'...Ice block.

Claims (1)

[Scope of Claims] 1 A part of the remaining liquid in the pipe is frozen to produce an ice block, the ice block is pumped with an inert gas such as nitrogen, and the remaining liquid in the pipe is pushed by the ice block. A method for recovering residual liquid in piping. 2. Freeze a liquid that is the same as or has the same properties as the liquid remaining in the pipe to produce an ice block, insert this ice block into the pipe and pump it with an inert gas such as nitrogen, and freeze the remaining liquid in the pipe with the ice block. A method for collecting residual liquid in piping, which is characterized by collecting by pushing.