JPS6251641B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a cryogenic medium supply device, and in particular,
Relates to equipment for supplying cryogenic LNG (liquefied natural gas) to seawater for the purpose of seawater desalination.

[Background technology] LNG is imported at extremely low temperatures (-161.5°C) and is used after being vaporized through heat exchange with seawater.
In seawater desalination using LNG cold energy, a technology is already known that uses the heat of vaporization of LNG to crystallize ice in seawater, and then separates it from seawater, washes it, and melts it to produce freshwater.

FIG. 1 shows a conventional device for supplying LNG to seawater. In this figure, seawater 2 as a liquid to be cooled is stored in a crystal canister 1 as a storage canister, and this seawater 2 is stirred. It is stirred by a machine 3 and circulated by a crystal can circulation pump 4,
Seawater 2 is introduced from the gas phase part of the crystal canister 1 through the LNG introduction pipe 5.
LNG is spread on the surface of the liquid phase, and the spread LNG is engulfed in the agitated seawater 2, and after taking heat from the seawater 2 and vaporizing it, it rises inside the crystal canister 1 and passes through the gas phase communication pipe 6. Flows into a gas heater (not shown) from
On the other hand, the seawater 2 in the crystal tank 1 is cooled by LNG and crystallized to form a slurry in which fine ice crystal grains are suspended, and this slurry is transferred to a melting tank (not shown) via a slurry outlet pipe 7. It's getting old.

However, in such conventional methods and devices, since LNG is dispersed from the gas phase of the crystallizer 1 to the surface of the seawater 2, a stirrer 3 and a crystallizer circulation pump 4 are required, and the overall equipment is It was a large project and required a lot of energy to operate. In addition, since LNG is dispersed into the gas phase, the temperature of the gas phase decreases, which is disadvantageous from the perspective of vaporizing LNG, and the latent heat and sensible heat of LNG decreases. It has the drawbacks of not being able to be used effectively enough, carrying the risk of causing a steam explosion phenomenon, and being more likely to generate interfacial blocks (ice blocks).
It was not possible to effectively utilize the cold energy of LNG.

In addition, not only when LNG is supplied to seawater,
A similar situation may occur when a cryogenic medium other than LNG is supplied to a cooled liquid other than seawater.

[Object of the Invention] An object of the present invention is to provide a cryogenic medium supply device that has simplified equipment and is capable of effectively utilizing the cold energy of the cryogenic medium.

[Structure of the Invention] Therefore, the present invention provides a nozzle for spouting a cryogenic medium into the liquid phase inside a storage can containing a liquid to be cooled, and also provides a nozzle for spouting a cryogenic medium around this nozzle and a container for storing the cryogenic medium spouted from the nozzle. An outlet for non-cryogenic fluid is arranged to prevent direct contact with the liquid to be cooled in the can, thereby preventing the occurrence of interfacial blocks and allowing the liquid to be cooled to effectively absorb the cold heat of the cryogenic medium. At the same time, by utilizing the stirring action of the bubbles of the cryogenic medium vaporized in the liquid to be cooled, it is possible to eliminate the conventional stirring device, etc., thereby achieving the above object.

[Description of Examples] Examples of the present invention will be described below based on the drawings.

FIG. 2 shows an embodiment in which the cryogenic medium supply device according to the present invention is applied to a crystallizer of a seawater desalination device using LNG cold energy. In the figure, a crystal canister 11 as a storage can has seawater 12 as a liquid to be cooled.
is stored in the can bottom 11A of the crystal can 11.
As shown in the enlarged view, a nozzle mounting pipe 13 is attached which communicates the inside and outside of the can.
A support flange 14 is provided at the outer end of the can. A nozzle 16 having a nozzle flange 15 on the base end side is inserted into the nozzle mounting pipe 13 from the outside of the can, and a natural gas as a non-cryogenic flow path is provided in the gap between the nozzle mounting pipe 13 and the nozzle 16. (NG) A flow path 17 for outflow is formed, and a natural gas return pipe 18 is formed in this flow path 17 for blowing out the natural gas flow.
One end of is connected. The other end of the natural gas reflux pipe 18 is connected to the gas phase in the crystal can 11 via a compressor 19 and a mist separator 20, and the natural gas in the gas phase is removed from liquid by the mist separator 20. After that, the natural gas is pressurized by a compressor 19 and introduced into the natural gas outflow channel 17.

The upper end of the natural gas outflow channel 17 is a natural gas outflow port 17A serving as a non-cryogenic fluid outflow port,
This outlet 17A is a nozzle port 16A of the nozzle 16.
It surrounds. The ejection of LNG from the nozzle port 16A and the outflow of NG from the outlet 17A are performed simultaneously, and direct contact between LNG and seawater 12 is prevented by such outflow of NG. Also, around the outflow port 17A, please tighten the outflow port 17A.
An outlet plate 21 is fixed which creates momentum for the outflow of the water. The outlet plate 21 and the nozzle 16 are preferably made of tetrafluoroethylene resin (trade name: Teflon) in order to prevent these parts from freezing.

The nozzle 16 also has a nozzle flange 1.
5 as a cryogenic medium introduction pipe having a fixed flange 22 sandwiching the support flange 14 between the
The LNG introduction pipe 23 is connected to the support flange 14
and fixed flange 22 are tightened together with tightening bolts 24 with nozzle flange 15 in between.

From the nozzle 16 into the seawater 12, that is, the crystal can 1
When LNG, which is a cryogenic medium, is directly injected into the liquid phase inside the tank 1, the seawater 12 is cooled by the cold heat of the LNG and crystallized, forming a slurry state. On the other hand, the vaporized NG is led out to the outside through the gas phase communication pipe 2.
6 to the outside of the can.

According to this embodiment, the LNG spouted from the nozzle port 16A is surrounded by the NG flowing out from the outlet 17A, thereby blocking direct contact between the LNG and the seawater 12.
In particular, the occurrence of interface blocks near the nozzle opening 16A can be prevented. In particular, when restricting the outflow of NG with the outlet plate 21, it is easy to add appropriate momentum to the outflow of NG, and it is easy to reliably block the LNG that is ejected with great force from the seawater 12.

In addition, since LNG is injected directly into the liquid phase of seawater 12 in crystal canister 11, the cold energy of LNG, that is, latent heat and sensible heat, is directly absorbed by seawater 12, making effective use of the cold energy of LNG. is planned. Furthermore, since LNG is not supplied to the gas phase within the crystal can 11, the temperature of the gas phase increases compared to the conventional method, which is advantageous in vaporizing LNG. Furthermore, even if LNG is injected directly into the liquid phase of seawater 12 at around room temperature, no steam explosion phenomenon will occur, so there is no safety risk.

Furthermore, sufficient stirring action can be obtained from the flow of LNG in the seawater 12 and the kinetic energy of the LNG bubbles generated in the seawater 12, so the agitator and circulation pump that were previously required are no longer necessary, simplifying the equipment. This has the effect of reducing operating energy.

Furthermore, since the nozzle 16 can be easily replaced from outside the crystal can 11, it is extremely convenient to replace the nozzle 16 when it is worn out, perform maintenance and inspection, etc.

In addition, in the above embodiment, the case where the present invention is applied to seawater desalination technology using LNG cold energy has been explained, but the present invention is not limited to the above case, and can be applied to LNG vaporization equipment to reduce the size of the equipment. Furthermore, it can be applied to the case where a cryogenic medium other than LNG is supplied to a liquid to be cooled other than seawater. Further, the nozzle 16 is not limited to the can bottom 11A, but may be attached to any can wall located in the liquid phase. Furthermore, non-cryogenic fluids
It is not limited to the case where NG is recycled and used, and any fluid other than cryogenic media may be used. For example, although there is a risk of disrupting the operational balance depending on the amount of outflow, it is possible to use heated water etc. as a non-cryogenic fluid. It's okay.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a cryogenic medium supply device that simplifies the equipment and makes effective use of the cold energy of the cryogenic medium.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the configuration of a conventional LNG supply device, and FIGS. 2 and 3 show the cryogenic medium supply device according to the present invention applied to a crystallizer for seawater desalination using LNG cold energy. FIG. 1 is a front view showing the overall configuration of one embodiment and a sectional view showing an enlarged main part. 11... Crystal can as storage can, 12... Seawater as liquid to be cooled, 16... Nozzle, 16A... Nozzle opening, 17... NG as flow path for non-cryogenic fluid outflow
Outflow channel, 17A... NG outlet as a non-cryogenic fluid outlet, 18... seawater introduction pipe as a non-cryogenic fluid introduction pipe, 23... as a cryogenic medium introduction pipe
LNG introduction pipe.

Claims (1)

[Claims] 1. A nozzle is provided to eject a cryogenic medium into the liquid phase of a storage can containing a liquid to be cooled, and a nozzle is provided around this nozzle to ensure direct contact between the cryogenic medium ejected from the nozzle and the liquid to be cooled in the storage can. 1. A cryogenic medium supply device, characterized in that an outlet is disposed through which a non-cryogenic fluid to be blocked flows out.