阅读说明：本技术 一种具有低液位物料抽提装置的低温全容罐 (Low-temperature full-capacity tank with low-liquid-level material extraction device ) 是由 应捷成 肖舒恒 鲁强 汪琳 于 2019-11-29 设计创作，主要内容包括：本发明提供了一种具有低液位物料抽提装置的低温全容罐,包括内罐、外罐、操作平台和能抽提低液位物料的物料抽提装置；所述物料抽提装置包括安装于操作平台上的物料循环罐和低温泵,安装于内罐底部的第一文丘里混合器以及相应的连接管路；物料循环罐内的低温介质可以经低温泵和引入管路进入第一文丘里混合器,使得内罐中的低温介质能够在压力差作用下经第一文丘里混合器的吸入孔进入第一文丘里混合器中,混合后经引出管路进入物料循环罐。本发明能够将低温全容罐内泵柱中潜液泵无法抽提的低液位的低温介质抽提出来,减小低温全容罐的无效容积,提高全容罐的容积利用率；所述低液位物料抽提装置还可以作为泵柱之外的备用抽提设施。(The invention provides a low-temperature full-capacity tank with a low-liquid-level material extraction device, which comprises an inner tank, an outer tank, an operation platform and a material extraction device capable of extracting low-liquid-level materials; the material extraction device comprises a material circulation tank and a low-temperature pump which are arranged on an operation platform, a first Venturi mixer arranged at the bottom of the inner tank and a corresponding connecting pipeline; the low-temperature medium in the material circulating tank can enter the first Venturi mixer through the low-temperature pump and the introducing pipeline, so that the low-temperature medium in the inner tank can enter the first Venturi mixer through the suction hole of the first Venturi mixer under the action of pressure difference, and the mixed low-temperature medium enters the material circulating tank through the leading-out pipeline. The invention can extract low-temperature medium with low liquid level which can not be extracted by the immersed pump in the pump column in the low-temperature full-capacity tank, reduce the invalid volume of the low-temperature full-capacity tank and improve the volume utilization rate of the full-capacity tank; the low-liquid-level material extraction device can also be used as a spare extraction facility outside the pump column.)

1. A low-temperature full-capacity tank with a low-liquid-level material extraction device comprises an inner tank, an outer tank surrounding the periphery of the inner tank and an operation platform arranged at the top of the outer tank; the low-temperature full-capacity tank is characterized by also comprising a material extraction device capable of extracting low-liquid-level materials; the material extraction device comprises:

the material circulating tank is arranged on the operating platform; the low-temperature medium is used for containing the low-temperature medium;

the first Venturi mixer is arranged at the bottom of the inner tank; the two ends of the water inlet are respectively provided with an inlet and an outlet, and the periphery of the water inlet is provided with a suction hole;

an inlet pipeline which is connected with the inlet of the first Venturi mixer through the outlet of the material circulating tank;

the outlet of the first Venturi mixer is connected with the inlet of the material circulating tank;

the cryogenic pump is arranged on the operating platform and is connected into the introducing pipeline;

when medium extraction is carried out, low-temperature medium in the material circulating tank enters the first Venturi mixer through the low-temperature pump and the introducing pipeline, so that the low-temperature medium in the inner tank can enter the first Venturi mixer through the suction hole under the action of pressure difference, and the low-temperature medium enters the material circulating tank through the leading-out pipeline after being mixed.

2. The cryogenic full-volume tank of claim 1, wherein the first venturi mixer comprises a convergent section, a throat section and a divergent section connected in series; the large end opening of the contraction section is used as an inlet and is connected with the introducing pipeline; the large end opening of the diffusion section is used as an outlet and is connected with the leading-out pipeline; two ends of the throat pipe section are respectively connected with the small end opening of the contraction section and the small end opening of the diffusion section; the suction hole is formed corresponding to the periphery of the throat pipe section and communicated with the inside of the throat pipe section; the first venturi mixer is disposed horizontally in the inner tank.

3. The cryogenic full-volume tank of claim 2, wherein the first venturi mixer further comprises a suction chamber disposed around the throat section and communicating with the interior of the throat section; the two ends of the suction cavity are respectively connected with the outer wall of the contraction section and the outer wall of the diffusion section; the suction hole is formed in the peripheral wall of the suction cavity.

4. The cryogenic full-volume tank of claim 2, wherein the suction port of the first venturi mixer opens into the peripheral wall of the throat section;

the first Venturi mixer further comprises a suction pipe correspondingly arranged at the suction hole, and the suction pipe is communicated with the inside of the inner tank.

5. The cryogenic full-tank according to claim 1, wherein the material circulating tank is further provided with a medium outlet for outputting cryogenic medium to the outside, and a liquid level control mechanism is provided to control the opening and closing of the medium outlet when a preset liquid level is reached, the preset liquid level being higher than a liquid level required for the operation of the cryogenic pump during medium extraction.

6. The cryogenic full-tank of claim 5, wherein the liquid level control mechanism is an overflow weir disposed in the material circulation tank; the outlet of the material circulating tank is communicated with the inner space of the overflow weir, and the medium outlet is communicated with the space outside the overflow weir.

7. The low-temperature full-capacity tank as claimed in claim 5, wherein the liquid level control mechanism is an overflow port arranged on the side wall of the material circulation tank, the height of the overflow port is higher than that of the outlet of the material circulation tank, and the overflow port is communicated with the medium outlet.

8. The low-temperature full-capacity tank as claimed in claim 5, wherein the liquid level control mechanism comprises a liquid level meter and a switch valve which are electrically connected, the liquid level meter is used for detecting the liquid level in the material circulation tank, and the switch valve is correspondingly arranged at the medium outlet.

9. The cryogenic full-volume tank of claim 1, wherein a control valve is provided on the inlet line to regulate flow in the inlet line, the control valve being located outside the outer tank; the cryogenic pump is located between the material circulation tank and the control valve.

10. The cryogenic full-capacity tank of claim 1, wherein the material extraction device further comprises a pressurizing unit, and the pressurizing unit is arranged on the lead-out pipeline to increase the power of the cryogenic medium flowing to the material circulation tank.

11. The cryogenic full-vessel tank of claim 10, wherein the pressurizing unit comprises:

the suction hole and the outlet of the second Venturi mixer are connected in series on the lead-out pipeline;

a pressurized introduction line communicating an inlet of the second venturi mixer and an outlet of the material recycle tank;

and the pressurization control valve is arranged on the pressurization leading-in pipeline so as to adjust the flow in the pressurization leading-in pipeline.

Technical Field

The invention relates to the technical field of low-temperature liquefied gas storage, in particular to a low-temperature full-capacity tank with a low-liquid-level material extraction device.

Background

Substances which are gaseous at normal temperature and normal pressure and can be liquefied after being properly frozen can be safely and efficiently stored by adopting a low-temperature normal-pressure storage tank. The substances meeting the characteristic include hydrocarbons such as methane, ethylene, ethane, propylene, propane, butylene, butane and the like related to the petrochemical industry, and ammonia and the like commonly used in the chemical industry. Methane is the major component of natural gas and propane and butane are the major components of liquefied gases, a significant proportion being used as clean energy sources for industrial and residential use. With the increasing importance of the world on environmental protection, the consumption of clean energy such as Liquefied hydrocarbons (hydrocarbons) and Liquefied Natural Gas (LNG) is increasing, the number and production scale of petrochemical enterprises that further process hydrocarbons as raw materials are increasing, and the demand for large cryogenic storage tanks for storing these clean energy and Liquefied hydrocarbons is also increasing.

Based on the consideration of the aspect of safety, the existing large-scale low-temperature full-capacity storage tank wall and the tank bottom do not allow holes to be formed, and pipelines connected with the storage tank all adopt an upward-feeding and upward-discharging mode, namely enter and exit from the tank top. Because the storage tank diameter, height are great, tank deck space height plus tank wall height has been greater than the vacuum height of inhaling of liquid far away, and the discharge pump can only adopt submerged mode work, adopts low temperature immersed pump promptly.

When the low-temperature immersed pump is started, enough low-temperature medium is required in the storage tank, and the minimum liquid level is ensured not to be lower than the minimum operable liquid level height required by the low-temperature immersed pump. The lowest operable liquid level of the current low-temperature immersed pump plus a certain safety marginThe amount of the waste gas is usually about 1.2m, namely the working dead zone is usually in the range of 1.2m at the bottom of the low-temperature full-capacity tank, so that the invalid working volume of the tank bottom is large. For example, 50000m³The diameter of the inner tank of the low-temperature storage tank is about phi 46m, and the height and volume of 1.2m are about 1994m³；80000m³The diameter of the inner tank of the low-temperature storage tank is about phi 59m, the height of the inner tank is 1.2m, and the volume of the inner tank is about 3280m³；160000m³The diameter of the inner tank of the low-temperature storage tank is about phi 87m, the height of the inner tank is 1.2m, and the volume is about 7134m³。

The materials with invalid working volume at the bottom of the tank cannot be discharged out of the tank through the low-temperature immersed pump, and if the storage tank needs to be stopped for maintenance, the materials at the bottom can be discharged only by vaporization, so that the energy consumption is very high, and the period is very long.

Disclosure of Invention

The invention aims to provide a low-temperature full-capacity tank with a low-liquid-level material extraction device, which solves the problems that the invalid working volume at the bottom of a storage tank is too large and too many residual media cannot be extracted in the prior art.

In order to solve the technical problems, the invention adopts the following technical scheme: a low-temperature full-capacity tank with a low-liquid-level material extraction device comprises an inner tank, an outer tank surrounding the periphery of the inner tank and an operation platform arranged at the top of the outer tank; the low-temperature full-capacity tank also comprises a material extraction device capable of extracting low-liquid-level materials; the material extraction device comprises: the material circulating tank is arranged on the operating platform and is used for containing a low-temperature medium; the first Venturi mixer is arranged at the bottom of the inner tank; the two ends of the water inlet are respectively provided with an inlet and an outlet, and the periphery of the water inlet is provided with a suction hole; an inlet pipeline which is connected with the inlet of the first Venturi mixer through the outlet of the material circulating tank; the outlet of the first Venturi mixer is connected with the inlet of the material circulating tank; the cryogenic pump is arranged on the operating platform and is connected into the introducing pipeline; when medium extraction is carried out, low-temperature medium in the material circulating tank enters the first Venturi mixer through the low-temperature pump and the introducing pipeline, so that the low-temperature medium in the inner tank can enter the first Venturi mixer through the suction hole under the action of pressure difference, and the low-temperature medium enters the material circulating tank through the leading-out pipeline after being mixed.

The first Venturi mixer comprises a contraction section, a throat section and a diffusion section which are connected in sequence; the large end opening of the contraction section is used as an inlet and is connected with the introducing pipeline; the large end opening of the diffusion section is used as an outlet and is connected with the leading-out pipeline; two ends of the throat pipe section are respectively connected with the small end opening of the contraction section and the small end opening of the diffusion section; the suction hole is formed corresponding to the periphery of the throat pipe section and communicated with the inside of the throat pipe section; the first venturi mixer is disposed horizontally in the inner tank.

The first Venturi mixer also comprises a suction cavity which is annularly arranged on the periphery of the throat pipe section and communicated with the interior of the throat pipe section; the two ends of the suction cavity are respectively connected with the outer wall of the contraction section and the outer wall of the diffusion section; the suction hole is formed in the peripheral wall of the suction cavity.

The suction hole is formed in the outer peripheral wall of the throat section; the first Venturi mixer further comprises a suction pipe correspondingly arranged at the suction hole, and the suction pipe is communicated with the inside of the inner tank.

The material circulating tank is also provided with a medium output port for outputting low-temperature medium to the outside, and a liquid level control mechanism is arranged for controlling the opening and closing of the medium output port when a preset liquid level is reached, wherein the preset liquid level is higher than the liquid level required by the operation of the low-temperature pump when the medium is extracted.

Wherein the liquid level control mechanism is an overflow weir arranged in the material circulating tank; the outlet of the material circulating tank is communicated with the inner space of the overflow weir, and the medium outlet is communicated with the space outside the overflow weir.

The liquid level control mechanism is an overflow port arranged on the side wall of the material circulating tank, the height of the overflow port is higher than that of an outlet of the material circulating tank, and the overflow port is communicated with the medium output port.

The liquid level control mechanism comprises a liquid level meter and a switch valve which are electrically connected, the liquid level meter is used for detecting the liquid level in the material circulating tank, and the switch valve is correspondingly arranged at the medium output port.

Wherein a control valve is arranged on the introducing pipeline to adjust the flow in the introducing pipeline, and the control valve is positioned outside the outer tank; the cryogenic pump is located between the material circulation tank and the control valve.

The material extraction device further comprises a pressurizing unit, and the pressurizing unit is arranged on the lead-out pipeline to increase the power of the low-temperature medium flowing to the material circulation tank.

Wherein the pressurizing unit includes: the suction hole and the outlet of the second Venturi mixer are connected in series on the lead-out pipeline; a pressurized introduction line communicating an inlet of the second venturi mixer and an outlet of the material recycle tank; and the pressurization control valve is arranged on the pressurization leading-in pipeline so as to adjust the flow in the pressurization leading-in pipeline.

According to the technical scheme, the invention has at least the following advantages and positive effects: the low-temperature full-capacity tank is provided with a material extraction device capable of extracting low-liquid-level materials, wherein the material extraction device comprises a material circulation tank and a low-temperature pump which are positioned on an operation platform at the top of the tank, a Venturi mixer which is positioned at the bottom of an inner tank, and corresponding connecting pipelines. The low-temperature medium in the material circulation tank enters the Venturi mixer through the low-temperature pump, and according to the Bernoulli principle and the momentum transfer principle, the low-temperature medium can form local low-pressure and high-speed flow entrainment effect in the Venturi mixer, so that the low-temperature medium in the inner tank enters the Venturi mixer through the suction hole under the action of pressure difference, and the mixed low-temperature medium returns to the material circulation tank together. In the circulation process, the flow of the low-temperature medium returning to the material circulation tank is larger than the flow of the low-temperature medium pumped out of the material circulation tank, and the difference part is the extracted low-temperature medium.

This material extraction device mainly holds jar mesocarp pump as low temperature and takes the supplementary ejection of compact measure after stopping to minimum liquid level, through this kind of extraction device, can extract the low temperature medium of the low liquid level that is in originally work "dead zone", the low temperature medium of suction hole place liquid level top of venturi mixer all can be extracted by this material extraction device, thereby can reduce the liquid level of low temperature full-capacity jar to the suction hole of first venturi mixer or the position department at suction pipe mouth place, this liquid level height is obviously less than the required minimum operatable liquid level height of prior art mesocarp pump, thereby can show the invalid volume that reduces low temperature full-capacity jar, improve the volume utilization of full-capacity jar. Under the condition of the same tank body size, the effective working volume of the full-capacity tank can be increased. And under the condition of a certain effective working volume, the height of the inner tank and the outer tank can be reduced, and the engineering investment is saved.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the cryogenic full-tank of the invention.

Fig. 2 is a schematic structural diagram of the material extraction device in fig. 1.

Fig. 3 is a schematic view of the mixing of the cryogenic medium of fig. 2 in a first venturi mixer.

Fig. 4 is a schematic structural diagram of another embodiment of the cryogenic full-tank of the invention.

Fig. 5 is a schematic structural diagram of the material extraction device in fig. 4.

FIG. 6 is a schematic diagram of another venturi mixer configuration.

The reference numerals are explained below: 1. an inner tank; 2. an outer tank; 3. an operating platform; 4. a pump column; 5. an immersed pump; 6/6a, a material extraction device; 61/61a, a material circulation tank; 6101/6101a, an outlet; 6102/6102a, an inlet; 6103/6103a, media outlet; 6104a, overflow port; 611. an overflow weir; 62. a first venturi mixer; 621. a contraction section; 622/622b, a throat section; 623. a diffuser section; 624. a suction chamber; 62b, a venturi mixer; 625b, a suction pipe; 6201. an inlet; 6202/6202b, suction hole; 6203. an outlet; 63. an inlet line; 64/64a, a lead-out line; 641a, a first lead-out section; 642a, a second lead-out section; 65. a cryopump; 66. a control valve; 67. a pressurizing unit; 671. a second venturi mixer; 6711. an inlet; 6712. a suction hole; 6713. an outlet; 672. a pressurized introduction line; 673. a pressurization control valve.

Detailed Description

Exemplary embodiments that embody features and advantages of the invention are described in detail below in the specification. It is to be understood that the invention is capable of other embodiments and that various changes in form and details may be made therein without departing from the scope of the invention and the description and drawings are to be regarded as illustrative in nature and not as restrictive.

The invention provides a low-temperature full-capacity tank which is used for storing liquefied low-temperature media, wherein the low-temperature media can be hydrocarbons such as methane, ethylene, ethane, propylene, propane, butylene, butane and the like, and can also be ammonia and the like commonly used in the chemical industry.

Referring to fig. 1, the low-temperature full-capacity tank provided in this embodiment generally includes an inner tank 1 for storing a low-temperature medium, an outer tank 2 surrounding the outer periphery of the inner tank 1, an operation platform 3 disposed on the top of the outer tank 2, a pump column 4 penetrating from the top of the outer tank 2 to the bottom of the inner tank 1, an immersed pump 5 disposed in the pump column 4, and a material extraction device 6 for extracting a low-level material from the bottom of the inner tank 1.

The inner tank 1 and the outer tank 2 approximately comprise a horizontally arranged bottom plate and a cylinder body vertically arranged on the bottom plate, and heat insulation layers are arranged between the bottom plates of the inner tank 1 and the outer tank 2 and between the cylinder bodies. The top of outer jar 2 has the vault and hangs the roof of locating the vault below, also sets up the heat insulation layer between vault and the roof. The top plate is connected with the inner tank 1 in a soft sealing way. The pump column 4 extends through the top of the outer vessel 2 into the bottom of the inner vessel 1. The immersed pump 5 is arranged at the bottom of the pump column 4, is immersed in the low-temperature medium in the inner tank 1, and is used for conveying the low-temperature medium in the inner tank 1 outwards through the pump column 4. The operation platform 3 is fixed on the top of the outer tank 2, and can be used for accommodating various pipeline valves, working accessories and the like of the low-temperature full-capacity tank and providing operation and maintenance for operators on the operation platform.

Compared with the low-temperature full-capacity tank in the prior art, the low-temperature full-capacity tank in the embodiment is provided with the material extraction device 6, which is used as a supplementary discharging measure after the submersible pump 5 is stopped to pump to the lowest liquid level L1 so as to reduce the invalid volume of the low-temperature full-capacity tank, and it is worth mentioning that the material extraction device 6 related to the invention not only can extract low-level materials (namely, low-temperature media below the lowest operable liquid level L1 of the submersible pump 5), but also can be operated in a liquid level range in which the submersible pump 5 in the pump column 4 can work, so that the material extraction device can also be used as a small-flow output backup facility outside the submersible pump 5 in some cases. The material extraction device 6 will be mainly described in detail with reference to fig. 2, and for other specific structures of the inner tank 1, the outer tank 2, the operation platform 3, the pump column 4 and the immersed pump 5, reference may be made to the structure of the related art of the full-tank, and details thereof will not be given here.

Referring to fig. 1 and 2 together, the material extraction device 6 of the present embodiment includes a material circulation tank 61, a first venturi mixer 62, an introduction line 63, an extraction line 64, and a cryogenic pump 65. Further, a control valve 66 is provided in the introduction line 63.

The material circulation tank 61 in this embodiment is a horizontal cryogenic tank and is installed on the operation platform 3. The material circulation tank 61 is used for containing low-temperature media, and cold insulation materials can be wrapped outside the material circulation tank 61.

Referring to the view direction of fig. 2, a weir 611 is provided in the material circulation tank 61, the weir 611 divides the internal space of the material circulation tank 61 into two parts, and when the low temperature medium in the weir 611 (i.e., on the left side of the weir 611 in the figure) exceeds the height of the weir 611, the low temperature medium overflows the outside of the weir 611 (i.e., on the right side of the weir 611 in the figure). The space on the left side of the overflow weir 611 should meet the requirement of the circulation volume of the cryogenic medium required for medium extraction, and the height of the overflow weir 611 should meet the requirement of the lowest operating liquid level of the cryogenic pump 65, on the basis of which the height of the overflow weir 611 is set according to the actual situation.

The bottom of the left end of the material circulating tank 61 is provided with an outlet 6101, and the outlet 6101 is communicated with the space enclosed in the overflow weir 611, and is used for outputting the low-temperature medium when the medium extraction is carried out.

The bottom of the right end of the material circulation tank 61 is also provided with a medium output port 6103, and the medium output port 6103 is communicated with the space in the material circulation tank 61 outside the overflow weir 611 for outputting low-temperature medium to the outside.

The top of the material circulation tank 61 is provided with an inlet 6102 near the left side for receiving the low temperature medium.

The first venturi mixer 62 is horizontally placed on the bottom plate of the inner tank 1 so as to have a low installation height. The first venturi mixer 62 is a liquid-liquid mixer, which mainly comprises a contraction section 621, a throat section 622 and a diffusion section 623 connected in sequence. In this embodiment, the first venturi mixer 62 further has a suction chamber 624.

The convergent section 621 and the divergent section 623 are both hollow structures with gradually changing cross sections, the large end opening of the convergent section 621 serves as the inlet 6201 of the first venturi mixer 62, and the large end opening of the divergent section 623 serves as the outlet 6203 of the first venturi mixer 62. One end of the throat section 622 is connected to the small end opening of the convergent section 621 and the other end is aligned with the small end opening of the divergent section 623.

The suction chamber 624 is circumferentially disposed about the throat section 622, forming a dual chamber structure at the throat section 622. The suction chamber 624 is connected at both ends to the outer wall of the contraction section 621 and the outer wall of the expansion section 623, respectively. The outer circumferential wall of the suction chamber 624 is opened with a plurality of suction holes 6202, and the suction holes 6202 communicate with the inside of the inner tank 1, so that the low-temperature medium in the inner tank 1 can be sucked into the suction chamber 6222. An annular cavity is formed between the suction cavity 624 and the throat section 622, the suction cavity 624 is communicated with the interior of the throat section 622, and the low-temperature medium in the suction cavity 624 can further enter the throat section 622.

An introducing pipe 63 passes through the top of the outer tank 2 and is connected with an inlet 6201 of the first venturi mixer 62 through an outlet 6101 of the material circulation tank 61, so as to introduce the low-temperature medium in the material circulation tank 61 into the first venturi mixer 62 for extraction operation.

The outlet line 64 also passes through the top of the outer tank 2 and is connected to the inlet 6102 of the material circulation tank 61 through the outlet 6203 of the first venturi mixer 62 to lead the low-temperature medium in the first venturi mixer 62 out to the material circulation tank 61.

A cryogenic pump 65 is mounted on the operation platform 3 and connected to the introduction line 63 to provide motive force for the flow of cryogenic medium. The cryopump 65 is a non-submerged pump, i.e., it need not be immersed in a cryogenic medium, and may be of any configuration.

The control valve 66 is disposed on the introducing pipeline 63, on one hand, the on-off of the introducing pipeline 63 is controlled, and simultaneously, the flow of the low-temperature medium in the introducing pipeline 63 can be adjusted. The control valve 66 is located downstream of the cryopump 65 but outside of the outer tank 2.

The material circulation tank 61, the first venturi mixer 62, the inlet line 63, the outlet line 64, the cryogenic pump 65 and the control valve 66 are all required to be capable of withstanding the temperature of the extracted cryogenic medium and are made of cryogenic materials capable of withstanding the corresponding temperatures.

With reference to fig. 2 and 3, the material extraction device 6 works according to the following principle: in the medium extraction, the low-temperature medium in the material circulation tank 61 enters the first venturi mixer 62 through the introducing line 63 under the power of the low-temperature pump 65, and for the convenience of understanding, the part of the low-temperature medium introduced into the first venturi mixer 62 from the material circulation tank 61 is referred to as initial low-temperature medium F0. According to Bernoulli (energy conservation) principle and momentum transfer principle (momentum conservation), after the initial low-temperature medium F0 enters the first Venturi mixer 62, in the process of flowing from the contraction section 621 to the throat section 622, the flow cross-sectional area is reduced, the flow speed is increased, the pressure is reduced, so that local low-pressure and high-speed flow entrainment effect is formed at the throat section 622, and the low-temperature medium Fi in the inner tank 1 enters the suction hole 6202 under the action of pressure difference

In the first venturi mixer 62, the sucked low-temperature medium Fi is mixed with the initial low-temperature medium F0, and the mixed low-temperature medium Fm enters the material circulation tank 61 through the lead-out pipe 64 after the flow velocity is reduced and the pressure is increased due to the increase of the flow cross-sectional area in the diffuser section 623. In this embodiment, the suction cavity 624 is further disposed on the periphery of the throat section 622 of the first venturi mixer 62, and the low-temperature medium in the inner tank 1 is firstly sucked into the suction cavity 624 and then enters the throat section 622 for mixing, so that momentum of the initial low-temperature medium F0 can be more effectively utilized, and the mixed low-temperature medium flows back to the material circulation tank 61 more smoothly.

The flow rate of the low-temperature medium reaching the material circulation tank 61 is greater than the flow rate of the initial low-temperature medium initially pumped from the material circulation tank 61 into the first venturi mixer 62, and the excess is the low-temperature medium extracted from the inner tank 1. Through the above continuous circulation process, the low-temperature medium in the inner tank 1 can be continuously extracted into the material circulation tank 61.

The low temperature medium in the material circulation tank 61 positioned in the overflow weir 611 is used for maintaining the medium extraction operation, and after the low temperature medium in the material circulation tank 61 exceeds the overflow weir 611, the low temperature medium exceeding the height of the overflow weir 611 can be conveyed outwards through the medium outlet 6103.

Referring to fig. 4 and 5, in another embodiment of the low-temperature full-capacity tank, the material extraction device 6a is further provided with a pressurizing unit 67 on the basis of the previous embodiment, and the pressurizing unit 67 is arranged on the leading-out pipeline 64 and is used for increasing the power of the mixed low-temperature medium flowing to the material circulation tank 61a so that the low-temperature medium flows back to the material circulation tank 61a more smoothly, which is suitable for extracting the high-level low-temperature full-capacity tank, such as the high-level low-temperature full-capacity tank.

In this embodiment, the pressurizing unit 67 includes a second venturi mixer 671, a pressurizing introduction line 672, and a pressurizing control valve 673.

The second venturi mixer 671 may have the same composition structure as the first venturi mixer 62. The suction hole 6712 and the outlet 6713 of the second venturi mixer 671 are connected in series to the lead-out line 64a, specifically, the lead-out line 64a is divided into a first lead-out section 641a and a second lead-out section 642a, the first lead-out section 641a connects the outlet 6203 of the first venturi mixer 62 and the suction hole 6712 of the second venturi mixer 671, and the second lead-out section 642a connects the outlet 6713 of the second venturi mixer 671 and the inlet 6102a of the material circulation tank 61 a.

The pressurized introduction line 672 communicates the inlet 6711 of the second venturi mixer 671 with the outlet 6101a of the material circulation tank 61a to introduce from the material circulation tank 61a certain initial low-temperature medium into the second venturi mixer 671, which initial low-temperature medium is further mixed in the second venturi mixer 671 with the mixed low-temperature medium coming out of the first venturi mixer 62, raising the pressure, so that the low-temperature medium has a greater momentum to return from the second lead-out section 642a to the material circulation tank 61 a.

A pressurization control valve 673 is provided in the pressurization introducing line 672 to control on/off of the pressurization introducing line 672 and to regulate the flow rate in the pressurization introducing line 672.

As in the previous embodiment, the second venturi mixer 671, the pressurized introduction line 672 and the pressurized control valve 673 are also required to be able to withstand the temperature of the cryogenic medium extracted, being made of cryogenic materials able to withstand the respective temperatures.

In this embodiment, a second venturi mixer 671 is used to increase the power of the refluxing low temperature medium to form a two-stage series extraction process. In other embodiments, if the extraction height is larger and the reflux power is insufficient, more venturi mixers may be connected in series to the leading line 64/64a to form a multistage series extraction process, and the connection manner of the multistage series extraction may be similar.

Another difference of the present embodiment compared to the previous embodiment is that the material circulation tank 61a employs a vertical storage tank. The inlet 6102a of the material circulation tank 61a is located at the top and the outlet 6101a of the material circulation tank 61a is located on the side wall near the bottom. The material circulation tank 61a is not provided with an overflow weir 611, but the side wall of the material circulation tank 61a is provided with an overflow port 6104a, the height of the overflow port 6104a is higher than the outlet 6101a of the material circulation tank 61a and higher than the liquid level required during medium extraction, and a medium outlet 6103a is led out from the overflow port 6104a in a communicating manner.

The vertical material circulation tank 61a is also applicable to the material extraction device 6 in the previous embodiment.

In the above two embodiments, the material circulation tank 61/61a is formed with a liquid level control mechanism by adopting the structures of the overflow weir 611 and the overflow port 6104a, respectively, so as to control the opening and closing of the medium output port 6103/6103a when a preset liquid level is reached. In other embodiments, not shown, the liquid level control mechanism may further include a liquid level meter and a switch valve electrically connected to each other, the liquid level meter being configured to detect a liquid level in the material circulation tank, and the switch valve being correspondingly disposed at the medium outlet.

Referring to FIG. 6, the venturi mixer 62/671 of the above embodiments may also be replaced with the configuration shown in FIG. 6. In the configuration shown in fig. 6, the venturi mixer 62b is not provided with the suction chamber 624, but a plurality of suction holes 6202b are formed in the outer peripheral wall of the throat section 622b, and a suction pipe 625b is provided corresponding to each suction hole 6202 b. After the initial low-temperature medium F0 is introduced into the constriction 621 of the venturi mixer 62b, the low-temperature medium Fi in the inner tank 1 can be introduced into the throat section 622b through the suction pipe 625b under the action of the pressure difference, and mixed with the initial low-temperature medium Fi, and the mixed low-temperature medium Fm is led out to the next flow path.

In other embodiments, not shown, the suction pipe 625b may be eliminated, and the low-temperature medium Fi in the inner tank 1 is directly sucked through the suction holes 6202b in the outer peripheral wall of the throat section 622 b. In addition, with the configuration of the first venturi mixer 62 of the above embodiment, a suction pipe may be additionally provided at the suction hole 6202 of the suction chamber 624. Similarly, a suction pipe may be added to the suction hole 6712 of the second venturi mixer 671.

Based on the above description, when the low-temperature full-capacity tank in each embodiment of the present invention is in normal operation, the low-temperature medium is output outwards through the pump column 4 by the power of the immersed pump 5. Depending on the minimum operational level required for the activation and maintenance of the immersed pump 5, the immersed pump 5 can minimize the liquid level in the cryogenic tank to L1 shown in fig. 1 and 3, where L1 is approximately 1.2m or so, as required by a typical immersed pump 5 of the prior art. When the liquid level in the low-temperature full-capacity tank is lowered to the position L1, after the immersed pump 5 is stopped, if low-temperature medium needs to be further extracted from the inner tank 1, the low-temperature medium is extracted by the material extraction device 6/6a, and the material extraction device 6/6a continuously extracts the low-temperature medium at the bottom of the inner tank 1 according to the above-introduced working principle until the liquid level is lowered to the position of the first Venturi mixer 62, and the liquid level is positioned at the position L2. The L2 can be approximately 0.2m to 0.3 m. Compared with 1.2m of L1, the liquid level in the inner tank 1 can be reduced by about 1m, the invalid volume of the low-temperature full-capacity tank is obviously reduced, and the volume utilization rate of the low-temperature full-capacity tank is improved.

In the low-temperature full-capacity tank, the power part and the control part of the material extraction device 6/6a are both arranged outside the outer tank 2, except that the Venturi mixer 62/671/62b and the pipeline part need to be immersed in a low-temperature medium, no other equipment or cable is immersed in the low-temperature medium, and the tank internal parts can realize the maintenance-free operation of the storage tank in the whole life cycle.

It should be noted that when the low-temperature full-capacity tank works at a position where the liquid level is higher than L1, the material circulation tank 61/61a of the material extraction device 6/6a may not store the low-temperature medium, and when low-level medium extraction is required, a certain amount of low-temperature medium is filled into the material circulation tank 61/61a as the initial power flow.

While the present invention has been described with reference to several exemplary embodiments, it is understood that the terminology used is intended to be in the nature of words of description and illustration, rather than of limitation. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.