JP2017051892A - Gas-liquid mixer and gas-liquid mixing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a uniform mixture liquid from stable gas-liquid mixture, and to secure the feed of the mixture liquid in a stable condition even when there is a sudden change in characteristics such as the flow rate, pressure, or temperature of gas components or liquid components upon the gas-liquid mixture of gas components with liquid components.SOLUTION: A gas-liquid mixer comprises a top stage 10, having a gas introducer 1 and a liquid introducer 2 that introduce a gas component G and a liquid component L and a distributer 3 that distributes the gas component G and the liquid component L, a packed bed 20, and a bottom stage 30 having a mixture liquid reservoir 4 and a mixture liquid feeder 5, and has a liquid extractor T capable of extracting a part of the liquid component L stored in a liquid reservoir 3a and a flow rate adjuster V1 of the liquid component L to extract a part of the liquid component L stored in the liquid reservoir 3a, so that the liquid level height h of the liquid reservoir 3a is rapidly controlled and adjusted by an extraction amount of the liquid component L. A mixture liquid M extracted out of the bottom stage 30 is fed out by a feed-out pump 6.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas-liquid mixing apparatus and a gas-liquid mixing method, and specifically, for example, a separated gas when a liquefied natural gas (hereinafter sometimes referred to as “LNG”) stored in a storage tank is supplied. The present invention relates to a gas-liquid mixing apparatus and a gas-liquid mixing method used for gas-liquid mixing of boil-off gas as a component (hereinafter sometimes referred to as “BOG”) and LNG as a liquid component.

  Natural gas (NG) is stored as liquefied natural gas (LNG) for convenience of transportation and storage, and after being vaporized, it is mainly used for thermal power generation and city gas. When transporting the stored LNG to various places, it is transferred as a low-temperature liquefied gas from the storage tank to a tank truck or the like. At this time, a part of the LNG stored at a low temperature is vaporized and generates BOG in the terminal part or the stopping part in the storage tank or in the transfer channel. Such BOG is preferably recovered under high pressure and low temperature conditions in order to prevent environmental considerations and economic loss, and various recovery devices have been proposed and implemented.

  For example, the BOG recondenser illustrated in FIG. 6 is an example of a device (and its associated control unit) that reliquefies all BOG generated at the delivery tip and mixes it with the rest of the delivered LNG. (See, for example, Patent Document 1). Specifically, the recondenser including the container 115 consists of two zones that do not interfere with each other. A packed bed 107 is disposed in the recondensed packing contact zone 111 located at the upper part of the container 115 to be accommodated, and the BOG fed from the BOG compression discharge path 114 is taken out from the discharge path of the LP pump 132. Contact with LNG122 and recondensate. The lower storage zone 112 located at the lower part of the containing container 115 serves as a liquid maintenance drum for the HP pump, where excess LNG 123 is introduced through the level control valve by more than half the maximum capacity. The excess of LNG from half of the maximum capacity bypasses the recondenser via the flow control bypass 124. Here, 108 and 109 are gate valves, 125 is a maintenance bypass, 126 is an HP pump flow passage, 127 is a kickback passage, 128 is an LNG discharge passage, 129 is a passage to the HP pump of the discharge LNG, Reference numeral 130 denotes an enclosed gas flow path, and 133 denotes a control flow path connection flow path.

European Patent Application Publication No. 2372231

However, in the gas-liquid mixing apparatus and the gas-liquid mixing method using gas-liquid contact such as the above-mentioned recondenser, the following various problems may occur.
(I) The flow rate of LNG is controlled based on the flow rate of BOG, and a part of LNG is directly introduced into the lower liquid layer in order to keep the liquid level below the recondenser (recapacitor) constant. The Under these conditions, when the flow rate of BOG changes abruptly (for example, when the storage tank of the supply source is filled with LNG), the flow rate of LNG introduced into the upper part of the packed bed is changed accordingly. It takes a predetermined time to flow down to the lower liquid layer through the layer, and the increase in the lower liquid layer occurs after the delay time. However, the flow rate of LNG introduced directly into the lower liquid layer cannot follow this fluctuation, and there is a temporary shift of the liquid level and the accompanying pressure fluctuation (overshoot or undershoot) of the gas-liquid mixing section. It sometimes occurred. The same applies to the occurrence of fluctuations in the pressure of the gas-liquid mixing part and the flow rate of the introduced LNG due to fluctuations in the amount taken out from the lower liquid layer.
(Ii) Also, when the flow rate of BOG changes rapidly, the balance between the flow rate of LNG introduced into the upper stage of the recondenser and the flow rate of LNG introduced into the lower liquid layer is greatly disrupted, and the head of the pump for LNG delivery There was a possibility that the stability of the supply amount could be affected by the load imbalance.
(Iii) Further, for example, when the flow rate of BOG suddenly increases, the temperature of the LNG introduced into the upper stage of the recondenser rises rapidly, and the heated LNG flows down directly into the lower liquid layer. The temperature of the layer rises. At this time, NPSH (net suction head) necessary for the operation of the pump used to deliver the mixed liquid taken out from the lower part of the recondenser cannot be secured, and cavitation occurs, which affects the stability of the delivery amount. There was a possibility. The same applies when the temperature of the BOG rises rapidly.
(Iv) These problems are not limited to the case of BOG as the gas component and LNG as the liquid component, but the gas component of the same component gas-liquid mixture of ammonia gas and liquefied ammonia as liquid component or methane gas and liquefied methane Gas-liquid mixing, or gas-liquid mixing in petroleum refined products such as kerosene and naphtha (gasoline) consisting of multiple components, and gas-liquid with different components such as gaseous nitrogen and LNG used for adjusting the calorific value of natural gas The same applies to the gas-liquid mixing apparatus and the gas-liquid mixing method used for mixing and the like.

  The object of the present invention is to provide a stable gas mixture even when there is a sudden change in characteristics such as the flow rate, pressure or temperature of the gas component or the liquid component during gas-liquid mixing of the gas component and the liquid component at a lower temperature than the gas component. An object of the present invention is to provide a gas-liquid mixing apparatus and a gas-liquid mixing method capable of producing a uniform liquid mixture by liquid mixing and ensuring the supply of the liquid mixture under stable conditions.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by the following gas-liquid mixing apparatus and gas-liquid mixing method, and have completed the present invention. .

In the gas-liquid mixing device according to the present invention, a gas introduction part into which a gas component is introduced, a liquid introduction part into which a supplied liquid component is introduced, and the introduced gas component and liquid component are respectively distributed. An upper part having a distribution part;
The gas component and the liquid component distributed in the distribution unit are introduced in a dispersed manner, and the gas component is dissolved or condensed by gas-liquid contact to dissolve or condense the gas component and gas-liquid mixing,
A lower stage portion provided at a lower portion of the packed bed and having a mixed liquid storage portion for storing a mixed liquid that has been gas-liquid mixed and a mixed liquid supply portion for discharging the stored mixed liquid; ,
In the distribution unit, a liquid storage unit for storing the introduced liquid component, a plurality of liquid distribution holes provided at the bottom of the liquid storage unit for distributing the stored liquid component, and the stored liquid component A plurality of gas distribution pipe parts through which the gas component flows through the upper part space and the packed bed upper space in a non-contact manner, a liquid level gauge for detecting the liquid level of the liquid storage part, and the liquid level A liquid level adjustment unit for adjusting the height,
The liquid level adjustment unit has a liquid extraction unit from which a part of the liquid component stored in the liquid storage unit can be taken out and a flow rate adjustment unit of the liquid component, and the liquid level of the liquid storage unit is It is controlled and adjusted according to the amount of the liquid component taken out.

In addition, the present invention is a gas-liquid mixing method in which a gas component and a liquid component supplied are brought into gas-liquid contact using a packed bed, and the gas component is dissolved or condensed in the liquid component to be gas-liquid mixed. Then, in the following step (1), in the upstream stage of the packed bed, the introduced gas component and the liquid component are respectively distributed by the distribution unit,
(2) In the packed bed in which the distributed gas component and liquid component are dispersedly introduced, gas-liquid mixing is performed;
(3) In the downstream stage of the packed bed, the gas-liquid mixed liquid mixture is stored, and the stored liquid mixture is supplied,
(4) In the distribution unit, the introduced liquid component is stored in the liquid storage unit, and the stored liquid component is distributed by a plurality of liquid distribution holes provided at the bottom of the liquid storage unit. The upstream stage is introduced into the packed bed, and the introduced gas component is in non-contact with the liquid component stored via a plurality of gas distribution pipe portions provided in proximity to the liquid storage portion. Is introduced into the packed bed from the space of
(5) A part of the liquid component stored in the liquid storage part is taken out, and the liquid level of the liquid storage part is controlled and adjusted by the amount of the liquid component taken out.

  As mentioned above, using a packed bed to make gas-liquid contact, producing a uniform mixed liquid, and taking it out with stable characteristics (pressure, temperature, etc.), the flow rate and characteristics of the delivered gas component or liquid component It can be very difficult when fluctuates. The inventor arranges a distribution unit capable of storing the introduced liquid component so as to have a predetermined liquid level height in the upper stage (upstream stage) of the packed bed, and also provides one of the stored liquid components. The liquid level of the liquid storage part can be quickly controlled and adjusted by taking out the part and adjusting the take-out amount. Specifically, for example, apart from the liquid distribution hole, a liquid extraction part that can always extract a predetermined amount is provided, and when the gas component increases (decreases), the extraction amount is immediately decreased (increased), It is possible to increase (decrease) the liquid component supplied to the packed bed by increasing (decreasing) the liquid surface height. This stabilizes the gas-liquid mixing conditions in the filling section, and even if there is a sudden change in characteristics such as the flow rate, pressure, or temperature of the gas component, a uniform mixed liquid is produced. It has become possible to provide a gas-liquid mixing apparatus and a gas-liquid mixing method that can ensure the delivery. Moreover, the temporary shift of the liquid level and the accompanying pressure fluctuation of the gas-liquid mixing part, which were the conventional problems, can be prevented. At the same time, for example, in the case of the gas component BOG and the liquid component LNG, it becomes gas-liquid mixing of the liquid component at a lower temperature than the gas component, and the temperature rise of the mixed LNG due to a rapid increase in the BOG flow rate can be mitigated, It became possible to produce a uniform mixed solution stably. In addition, in the case of gas-liquid mixing of low temperature gaseous nitrogen and higher temperature LNG like gaseous nitrogen and LNG, the temperature rise of gaseous nitrogen can be relieved.

The present invention provides a gas introduction part into which a supplied gas component is introduced, a liquid introduction part into which a supplied liquid component is introduced, and a distribution in which the introduced gas component and the liquid component are respectively distributed. An upper stage having a portion,
The gas component and the liquid component distributed in the distribution unit are introduced in a dispersed manner, and the gas component is dissolved or condensed by gas-liquid contact to dissolve or condense the gas component and gas-liquid mixing,
A lower stage portion provided at a lower portion of the packed bed and having a mixed liquid storage portion for storing a mixed liquid that has been gas-liquid mixed and a mixed liquid supply portion for discharging the stored mixed liquid; ,
In the distribution unit, a liquid storage unit for storing the introduced liquid component, a plurality of liquid distribution holes provided at the bottom of the liquid storage unit for distributing the stored liquid component, and the stored liquid component A plurality of gas distribution pipe parts through which the gas component flows through the upper part space and the packed bed upper space in a non-contact manner, a liquid level gauge for detecting the liquid level of the liquid storage part, and the liquid level A liquid level adjustment unit for adjusting the height,
The liquid level adjustment unit is capable of taking out a part of the liquid component stored in the liquid storage unit, a flow rate adjustment unit for the amount to be taken out, and a part of the extracted liquid component in the liquid storage again. A liquid reflux part and a flow rate adjustment part for the reflux liquid, and the liquid level of the liquid storage part is controlled and adjusted by the amount of liquid component taken out and the reflux flow rate of the liquid component to be refluxed. It is characterized by that.

In addition, the present invention is a gas-liquid mixing method in which a gas component and a liquid component supplied are brought into gas-liquid contact using a packed bed, and the gas component is dissolved or condensed in the liquid component to be gas-liquid mixed. Then, in the following step (1), in the upstream stage of the packed bed, the introduced gas component and the liquid component are respectively distributed by the distribution unit,
(2) In the packed bed in which the distributed gas component and liquid component are dispersedly introduced, gas-liquid mixing is performed;
(3) In the downstream stage of the packed bed, the gas-liquid mixed liquid mixture is stored, and the stored liquid mixture is supplied,
(4) In the distribution unit, the introduced liquid component is stored in the liquid storage unit, and the stored liquid component is distributed by a plurality of liquid distribution holes provided at the bottom of the liquid storage unit. The upstream stage is introduced into the packed bed, and the introduced gas component is in non-contact with the liquid component stored via a plurality of gas distribution pipe portions provided in proximity to the liquid storage portion. Is introduced into the packed bed from the space of
(5) A part of the liquid component stored in the liquid storage part is taken out, and a part of the taken out liquid component is recirculated to the liquid storage part, and the liquid level of the liquid storage part is It is characterized by being controlled and adjusted by the amount of liquid component taken out and the reflux flow rate of the liquid component to be refluxed.

  As described above, by removing a part of the liquid component stored in the liquid storage part, the liquid level of the liquid storage part can be quickly adjusted. On the other hand, the taken-out liquid component can be added to the liquid mixture supplied from the gas-liquid mixing apparatus and can be used as a raw material liquid component supplied to the gas-liquid mixing apparatus. Furthermore, the present invention makes it possible to obtain a high buffering function against abrupt fluctuations in the introduced gas component by expanding the adjustment range of the liquid surface height by returning it to the liquid reservoir.

Schematic which shows the 1st structural example of the gas-liquid mixing apparatus which concerns on this invention. Schematic which shows the 2nd structural example of the gas-liquid mixing apparatus which concerns on this invention. Schematic which shows the 3rd structural example of the gas-liquid mixing apparatus which concerns on this invention. Explanatory drawing which illustrates the verification result of the apparatus internal pressure fluctuation buffer function using the gas-liquid mixing apparatus according to the present invention Explanatory drawing which illustrates the verification result of the apparatus internal pressure fluctuation buffer function using the gas-liquid mixing apparatus according to the present invention Schematic illustrating a BOG recondenser as a gas-liquid mixing device according to the prior art

<Basic configuration example of gas-liquid mixing apparatus according to the present invention>
An outline of a basic configuration example (first configuration example) of a gas-liquid mixing apparatus (hereinafter referred to as “this device”) according to the present invention is shown in FIG. 1 (A), and a distributor 3 constituting this device is shown in FIG. Illustrated in (B). The apparatus includes a gas introduction unit 1 into which a gas component G and a liquid component L are introduced, a liquid introduction unit 2, an upper stage unit 10 having a distribution unit 3 that distributes the introduced gas component G and the liquid component L, and a packed bed. 20, a lower stage portion 30 having a mixed liquid storage portion 4 and a mixed liquid supply portion 5, a liquid storage portion 3 a for storing the introduced liquid component in the distribution portion 3, and a bottom portion of the liquid storage portion 3 a A plurality of liquid distribution holes 3b for distributing the stored liquid components and a plurality of gas distributions in which the gas components circulate in the upper stage space 10a and the packed bed upper space 20a in non-contact with the stored liquid components And a liquid level meter (not shown) for detecting the liquid level height h of the liquid storage unit 3a, and a liquid level adjusting unit for adjusting the liquid level height h. In the first configuration example of the apparatus, the liquid level adjustment unit includes a liquid extraction unit T that can partially extract the liquid component L stored in the liquid storage unit 3a and a flow rate adjustment unit V1 of the liquid component L. Features. The liquid mixture M taken out from the lower stage 30 is delivered by the delivery pump 6. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A part of the liquid component L stored in the liquid storage part 3a is taken out, and the liquid level height h of the liquid storage part 3a is rapidly controlled and adjusted by the amount of liquid component L taken out, so that the gas component G Alternatively, even when a transient change in the characteristics of the liquid component L occurs, it is possible to prevent a temporary shift of the liquid level and the accompanying pressure fluctuation of the gas-liquid mixing part (particularly the packed bed 20). At this time, the liquid component L is always taken out and controlled by increasing / decreasing it within the range of the upper and lower limit values with respect to the reference value of the extraction amount, or the liquid accompanying the increase in the gas component G on the basis of no extraction amount It is preferable to set according to the process to be used, such as a method of controlling by reducing the extraction amount corresponding to the increase of the component L.

  As a liquid level adjustment function, the apparatus includes a liquid extraction unit T and a flow rate adjustment unit V1, and the liquid level height h is adjusted by controlling the extraction amount of the liquid component L. Without providing a member other than a liquid level gauge (not shown) in the liquid reservoir 3a, the function of adjusting the liquid level height h can be secured, and the extracted liquid component L can be utilized. . For example, the extracted liquid component L is flow-adjusted by the flow adjusting unit V1, and differs by adding to the mixed liquid M flowing through the mixed liquid supply unit 5 via the liquid extracting unit T shown by the solid line in the figure. In the case of gas-liquid mixing of components, the liquid temperature and purity of the mixed liquid M to be delivered can be adjusted. In addition, as shown by the upper broken line in the drawing, a part of the extracted liquid component L is added to the liquid component L flowing through the liquid introducing portion 2 as a reflux liquid R, thereby introducing the liquid component introduced into the apparatus. While adjusting the amount of L introduced, the liquid level height h of the liquid reservoir 3 can be adjusted. In addition, as shown in the lower broken line in the figure, a part of the extracted liquid component L is further added to the mixed liquid storage section 4 via the lower liquid introducing section S, so that the liquid temperature of the mixed liquid M and Purity can be adjusted.

  The gas component G and the liquid component L introduced into the upper stage part 10 refer to a combination of a gas component and a liquid component that can be prepared by dissolving or condensing the gas component into the liquid component by gas-liquid contact. Specific examples include a gas of the same substance (component) and a liquid component in which the gas is liquefied, and a combination of a gas component of a different composition or a different substance and a liquid component in a low temperature state. For example, in the case of ammonia gas and liquefied ammonia as the same component, in the case of methane gas and liquefied methane, etc., or the gas component and the liquid component or gas component of petroleum refined products such as kerosene and naphtha (gasoline) consisting of a plurality of components Examples of the liquid component include LNG. In the latter case, the composition is different between the gas component and the liquid component, but the same liquid phase substance is formed by gas-liquid mixing. Moreover, the case where components differ like gaseous nitrogen and LNG used in the case of calorie | heat amount adjustment of natural gas is mentioned. Hereinafter, the case of BOG and LNG will be described as a specific example, but the present invention is not limited to this.

  In this apparatus, the gas component G and the liquid component L introduced into the upper stage portion 10 are individually and evenly dispersed by the distribution unit 3 without direct gas-liquid contact in the upper stage portion 10. It is introduced into the packed bed 20. At this time, it is preferable that the upper stage portion 10 has a temperature condition that can prevent the liquid component L from evaporating and a pressure condition that is the same as that of the packed bed 20 in which gas-liquid contact is performed. For example, in the case of gas-liquid mixing of BOG and LNG, the low temperature and high pressure conditions (for example, about −150 ° C., about 6 MPa) close to the storage conditions for LNG are used to stabilize LNG and to partially liquefy BOG. The efficiency of gas-liquid mixing in the packed bed 20 can be improved. Further, the flow rates of the introduced gas component G and liquid component L are set according to a desired flow rate of the liquid mixture M to be taken out.

  As illustrated in FIG. 1B, the distributor 3 provided in the upper stage portion 10 includes a liquid storage portion 3a for storing the introduced liquid component L and a plurality of portions provided at the bottom of the liquid storage portion 3a. A plurality of gas distribution pipe portions 3c that flow through the upper space 10a and the upper space 20a of the packed bed 20 in a non-contact manner with the liquid distribution holes 3b and the liquid component L in which the introduced gas component G is stored; A liquid level gauge (not shown) for detecting the liquid level of the liquid storage unit 3a. The liquid component L stored in the liquid storage part 3a is evenly distributed and flows down to the packed bed 20 by the plurality of liquid distribution holes 3b distributed evenly at the bottom of the liquid storage part 3a. At this time, when the liquid level height h of the liquid storage part 3a is controlled to be constant, the distributed liquid component L is introduced into the packed bed 20 at substantially the same falling speed, and stable gas-liquid mixing is performed. A uniform mixed solution M can be produced. On the other hand, the gas component G flows from the upper space 10a to the upper space 20a of the packed bed without directly contacting the liquid component L stored via the gas distribution pipe 3c. At this time, in order to distribute the gas component G evenly, the plurality of gas distribution pipe portions 3c are evenly distributed with respect to the cross section (the bottom surface of the liquid storage portion 3a) of FIG. It is preferable to make it.

[About liquid level adjustment function]
The liquid level height h of the liquid reservoir 3a is determined by the flow rate (Li) of the introduced liquid component L, the total amount (Ld) per unit time of the liquid component L flowing down from the liquid distribution hole 3b, and the flow rate adjusting unit V1. Determined by the flow rate of the liquid component L extracted through the liquid extraction portion T. At this time, a temporary shift of the liquid level with respect to a rapid increase in Li causes a change in gas-liquid mixing conditions as described above in the balance of temperature, pressure, and flow rates of both components. In this apparatus, in order to prevent the liquid level from rising, a part of the liquid component L is taken out via the liquid extraction part T provided in the liquid storage part 3a. By quickly controlling and adjusting the liquid level height h, the gas-liquid mixing conditions in the packed bed 20 can be achieved, and the mixed liquid M that is stably gas-liquid mixed can be secured.

[About packed bed]
In the packed bed 20, it is preferable that the liquid component L and the gas component G that are evenly distributed from the upper part make gas-liquid contact in a wider area for a longer time. Therefore, a porous non-adsorbing substance in which the liquid component L sufficiently permeates inside and temporarily stays is preferable as the filler forming the packed bed 20. Specific examples include silica / alumina-based or zeolite-based porous materials, or metal regular packing or irregular packing under low temperature conditions. In addition, the packed bed 20 is formed of a fluidized bed made of granular or finely packed filler or a fixed layer having a micro-flow passage such as a honeycomb shape, thereby enabling efficient gas-liquid contact with a small pressure loss. It can be carried out. At this time, the liquid component L in the low temperature state introduced into the packed bed 20 moves in the packed bed 20 and comes into contact with the gas component G in the liquid film formed between the surface layer of the filler and the filler. In the case of a component, the gas component G can be dissolved, and in the case of a non-soluble gas component G of a different component, it can be liquefied to produce a homogeneous mixed solution M. The packed bed 20 is preferably several to several tens of degrees C lower than the boiling point of the liquid component L as a condition that the gas component G is easily dissolved and mixed in the liquid component L.

<Gas-liquid mixing method according to the present invention>
The gas-liquid mixing method according to the present invention (hereinafter referred to as “the present method”) forms the following steps. Even if there is a sudden change in the characteristics of the introduced gas component or liquid component, it is possible to produce a uniform mixed solution by stable gas-liquid mixing and ensure the supply of the mixed solution under stable conditions. A case where the present apparatus is used will be described as an example.
(1) Introduction of gas component and liquid component In the upstream stage (upper stage part 10) of the distribution packed bed 20, the introduced gas component G and liquid component L are distributed by the distribution part 3, respectively. A specific distribution function will be described later in step (4).
(2) Mixing and distributing the gas component and liquid component In the packed bed 20 into which the distributed gas component G and liquid component L are dispersed and introduced, gas-liquid mixing is performed to produce a mixed solution M. Specifically, for example, a liquid component L in a low-temperature state introduced into the packed bed 20 formed of a porous filler moves through the packed bed 20 and is formed between the surface layer of the filler and the filler. By contacting the gas component G in the membrane, the gas component G is dissolved in the case of the same component, and in the case of the insoluble gas component G of a different component, it is liquefied to produce a mixed solution M.
(3) Delivery of mixed liquid In the downstream stage (lower stage part 30) of the packed bed 20, the mixed liquid M that has been gas-liquid mixed is stored, and the stored mixed liquid M is sequentially delivered. At this time, in the space above the mixed liquid reservoir 4 in the lower stage 30, the mixed liquid M flowing down from the packed bed 20 is in countercurrent contact with the gas component G that evaporates from the mixed liquid M stored in the mixed liquid reservoir 4. Dissolution or mixing of the gaseous component G occurs. The concentration of the liquid mixture M stored in the liquid mixture storage unit 4 can be maintained.
(4) In the distribution function distribution unit 3 for the gas component and the liquid component in the dispersion unit, the introduced liquid component L is stored in the liquid storage unit 3a, and the stored liquid component L is provided at the bottom of the liquid storage unit 3a. A plurality of gas distribution pipe portions 3c provided in the vicinity of the liquid storage portion 3a while being introduced into the packed bed 20 by being distributed by the plurality of liquid distribution hole portions 3b. Is introduced from the space 10a of the upstream stage 10 into the packed bed 20 via the upper space 20a in a non-contact manner with the liquid component L stored via the. By evenly distributing the gas component G and the liquid component L, uniform gas-liquid contact is performed, and a uniform mixed solution M can be produced.
(5) Liquid component storage in the dispersion part and adjustment of the liquid surface height of the storage part The liquid surface height h of the liquid storage part 3a is obtained by extracting a part of the liquid component L stored in the liquid storage part 3a, It is controlled and adjusted according to the amount of liquid component L taken out. Basically, it is controlled and adjusted so as to ensure a constant liquid level height ho. However, when a sudden characteristic change occurs, the liquid level height h in a short time is deviated from the reference liquid level height ho so as not to cause a transient pressure fluctuation in the packed bed 20. May be controlled and adjusted to height.

<Other configuration examples of the apparatus>
As another configuration example of the present apparatus, the first configuration example is basically used, and a part of the liquid component L stored in the liquid storage unit 3a can be extracted, and the flow rate adjustment for adjusting the extraction amount An apparatus in which the adjustment of the liquid level height h functions by the configuration including the part V1, the reflux part R that recirculates a part of the extracted liquid component L to the liquid storage part 3a, and the flow rate adjustment part V2 of the reflux liquid. FIG. 2 shows an outline of (second configuration example). A part of the liquid component stored in the liquid storage part 3a is taken out, and the liquid level height h of the liquid storage part 3a is determined so that the extraction amount of the liquid component L and the reflux flow rate of the liquid component to be refluxed (reflux liquid R). Even if a transient change in the characteristics of the gas component G or the liquid component L occurs due to the adjustment and control by the above, the liquid level temporarily shifts and the gas-liquid mixing section (packed bed) associated therewith 20) pressure fluctuation can be prevented. In the second configuration example of the apparatus, the liquid component L extracted from the liquid extraction unit T is added to the mixed liquid storage unit 4 via the lower liquid introduction unit S, and the flow rate is adjusted by the flow rate adjustment unit V3. By having it, the liquid temperature and purity of the liquid mixture M can be adjusted.

[Gas-liquid mixing method using the second configuration example of this apparatus]
When the second configuration example of the apparatus is used, the following steps are formed on the basis of the gas-liquid mixing method using the first configuration example of the apparatus. Common contents may be omitted.
(1) Introduction of gas component and liquid component In the upstream stage (upper stage part 10) of the distribution packed bed 20, the introduced gas component G and liquid component L are distributed by the distribution part 3, respectively.
(2) Mixing and distributing the gas component and liquid component In the packed bed 20 into which the distributed gas component G and liquid component L are dispersed and introduced, gas-liquid mixing is performed to produce a mixed solution M.
(3) Delivery of mixed liquid In the downstream stage (lower stage part 30) of the packed bed 20, the mixed liquid M that has been gas-liquid mixed is stored, and the stored mixed liquid M is sequentially delivered.
(4) In the distribution function distribution unit 3 for the gas component and the liquid component in the dispersion unit, the introduced liquid component L is stored in the liquid storage unit 3a, and the stored liquid component L is provided at the bottom of the liquid storage unit 3a. A plurality of gas distribution pipe portions 3c provided in the vicinity of the liquid storage portion 3a while being introduced into the packed bed 20 by being distributed by the plurality of liquid distribution hole portions 3b. Is introduced from the space 10a of the upstream stage 10 into the packed bed 20 via the upper space 20a in a non-contact manner with the liquid component L stored via the.
(5) Storage of liquid component in the dispersion part and adjustment of the liquid surface height of the storage part The liquid surface height h of the liquid storage part 3a is obtained while a part of the liquid component L stored in the liquid storage part 3a is taken out. A part of the extracted liquid component L is recirculated to the liquid storage unit 3a again, and is controlled and adjusted by the amount of liquid component L extracted and the recirculation flow rate of the liquid component to be recirculated.

<Third configuration example of the apparatus>
The third configuration example of the present apparatus is based on the first configuration example described above, and in the distribution unit 3, the liquid level height h and the introduced gas component G and liquid component in the liquid storage unit 3a that stores the liquid component L are provided. 3A to 3E illustrate an outline of an apparatus that controls and adjusts the liquid level height h of the liquid reservoir 3a using the L characteristic information as an index. As will be described later, the liquid level height h of the liquid reservoir 3a varies depending on the characteristics of the introduced gas component G and liquid component L, specifically, pressure, temperature, composition, and flow rate, and stable gas-liquid mixing. May become an obstacle. As shown in FIGS. 3 (A) and 3 (B), this apparatus is provided with a liquid level adjusting unit 3d in order to prevent such fluctuations in the liquid level, and the characteristics of the gas component G and liquid component L that cause it. Using the information (pressure, temperature, composition, flow rate) as an index, the amount of adjustment of the liquid level height h is controlled, so that the gas-liquid mixing conditions in the packed bed 20 are achieved, and the mixed liquid M is stably mixed. Can be secured.

Specifically, the case where the gas component G is BOG and the liquid component L is LNG will be described as an example. For example, if a temporary BOG occurs during the introduction of a newly transferred LNG to the storage tank, the flow rate of the BOG that is temporarily introduced into the apparatus will increase, the pressure and temperature will rise, and the composition will vary. Arise. At this time, as the flow rate of BOG increases, LNG introduced into the apparatus increases, and the liquid level height h of the liquid reservoir 3a increases. At the same time, the internal pressure of the packed bed 20 increases and the gas-liquid mixing conditions change. In addition, the liquid component L is present in a state where the liquid component L is heated and increased in the liquid storage unit 3a with an increase in the flow rate of the high-temperature BOG, and the heated liquid component L is present even when the BOG flow rate is restored. Supplied to the packed bed 20, the internal temperature of the packed bed 20 rises, and the gas-liquid mixing conditions change. Here, the influence of the transient fluctuation on the gas-liquid mixing condition in the packed bed 20 is generally assumed to be temperature>pressure> flow rate> composition. However, in this apparatus, the influence of each element can be reduced as follows.
(A) About the transient change of the temperature condition The transient change of the gas component G introduced into the present apparatus is greatly mitigated by passing through the distribution part 3a from the upper stage part 10, and is introduced into the packed bed 20. The In particular, since the gas component G has a relatively small heat capacity, the buffering function in the distribution unit 3a is high. On the other hand, the liquid component L has a relatively large heat capacity and a relatively high stability. In addition, when the gas component G is heated and increased in accordance with a transitional change of the gas component G, particularly with the heated gas component G, the liquid level in the liquid reservoir 3a is adjusted by adjusting the liquid level height h of the liquid reservoir 3a. By preventing the increase, transient changes are greatly mitigated.
(B) About a transient change in pressure conditions The liquid component L itself has a relatively small compressibility and high stability. On the other hand, the gas component G has a large compressibility and has a great influence on the gas-liquid mixing efficiency in the packed bed 20. In this apparatus, a liquid reservoir 3a is disposed at the boundary between the upper stage portion 10 and the packed bed 20 connected thereto, and the liquid reservoir constituting the head of the gas component G and the liquid component L flowing from the upper stage portion 10 to the packed bed 20 is provided. By adjusting the liquid level height h of the part 3a, the function of buffering a transient change in the pressure of the gas component G in the packed bed 20 can be activated.
(C) About the transient change of the flow rate condition The gas component G has a relatively limited influence on the transient change of the flow rate because the packed bed 20 becomes the rate-limiting condition of the flow, and the liquid component inside the packed bed 20 If a sufficient gas-liquid contact time (area) with L is secured, the influence on the packed bed 20 is mitigated and the influence on the gas-liquid mixing conditions is relatively small. On the other hand, since the introduction amount (flow rate) of the liquid component L to the packed bed 20 depends on the liquid level height h of the liquid reservoir 3a, the adjustment / control is important. This apparatus reduces or prevents transient fluctuations in the gas-liquid mixing conditions in the packed bed 20 by preventing the liquid level height h from increasing or by rapidly lowering the raised liquid level, thereby stably stabilizing the gas liquid. Mixing can be performed.
(D) When the composition of the gas component G to be introduced is changed abruptly with respect to the transient change in the composition conditions, the influence varies depending on the original composition itself and the state of the change. ) Is considered to have the same effect. Therefore, by adjusting and controlling the liquid level height h, transient fluctuations in the gas-liquid mixing conditions in the packed bed 20 can be mitigated / prevented, and gas-liquid mixing can be performed stably.

  In order to ensure such a function for managing the gas-liquid mixing conditions, in this apparatus, a flow rate measuring device for each component is provided in the gas introduction part 1 and the liquid introduction part 2 and is provided above the upper stage part 10 or the packed bed 20. A pressure gauge and a thermometer (not shown) are preferably provided. A control unit (not shown) calculates the braking amount of the liquid level adjusting unit 3d based on the output (PIC) of each meter, and adjusts the height h of the liquid level. Corresponding to changes in the characteristics of the gas component G and the liquid component L, transient fluctuations in the gas-liquid mixing conditions can be mitigated and prevented, and gas-liquid mixing can be performed stably.

The specific configuration of the liquid level adjustment unit 3d is preferably selected according to the type and characteristics of the gas component G or the liquid component L, but the configurations applicable to this apparatus are shown in FIGS. Illustrate. Of course, it is not limited to such a configuration.
FIG. 3C has a predetermined volume whose pressure can be adjusted by introducing and discharging a gas Go (for example, inert gas) from above, and includes a space communicating with the liquid component L stored in the liquid storage portion 3a. The liquid level adjustment part 3e is illustrated. The introduction amount of the gas Go is adjusted by the adjusting valve Vo, and the liquid level height h can be adjusted by drawing and discharging the liquid component L into the space. In addition, in the liquid level adjustment part 3e, it replaces with introduction | transduction of gas Go and it is also possible to connect with pressure reduction means and to adjust the vacuum degree of this space.
FIG. 3 (D) shows a liquid that is connected to the liquid component L stored in the liquid storage portion 3a, has a space to which the liquid component L is applied, and includes a piston Bo that is responsible for compression / expansion of the space from above. The surface adjustment part 3f is illustrated. By moving the piston Bo, the amount of liquid pushed out to the liquid reservoir 3a or the amount of liquid to be sucked is adjusted, and the liquid level height h can be adjusted.
3 (E) is provided with a piston Bo that communicates with the liquid component L stored in the liquid storage portion 3a, has a bellows structure space to which the liquid component L is applied, and is responsible for compression / expansion of the space. The liquid level adjustment part 3g is illustrated. By moving the piston Bo, the amount of liquid pushed out to the liquid reservoir 3a or the amount of liquid to be sucked is adjusted, and the liquid level height h can be adjusted.

<Verification of the effectiveness of the liquid level adjustment function>
The excellent function of this device was verified. Specifically, by using the apparatus according to the first configuration example, the pressure fluctuation of the packed bed 20 accompanying the rapid increase / decrease in the flow rate of the introduced gas component G, and the adjustment of the liquid level height h (removal flow rate) The buffer function of transient pressure fluctuation by adjustment) was verified.

[Verification conditions]
Using 100% methane (methane gas: temperature 25 ° C.) as the gas component G (equivalent to BOG), 100% methane (liquefied methane: temperature −160 ° C.) as the liquid component L (equivalent to LNG), and taking out liquefied methane as the mixed solution M In some cases, liquefied methane was always taken out and verified under the condition that the liquid level height h was adjusted by increasing / decreasing the take-out amount (bypass flow rate). Abrupt increase / decrease in the amount of methane gas introduced, increase / decrease in liquefied methane corresponding to this, difference in increase / decrease in liquefied methane introduced into the packed bed 20 due to increase / decrease in extraction amount of liquefied methane at this time, and presence / absence of extraction of liquefied methane The difference in increase / decrease in the pressure of the packed bed 20 was verified by simulation.

〔inspection result〕
As a result of setting and verifying the case where BOG is suddenly increased / decreased, excellent mitigation / prevention of this device against transient fluctuation of gas-liquid mixing conditions by adjusting the liquid level height h as follows: I was able to confirm the function.
(I) When BOG increases rapidly As illustrated in FIG. 4A, when the flow rate of BOG (methane gas) increases, the flow rate of LNG (liquefied methane) corresponds to this (for example, proportional control). To increase. At this time, a part of the liquefied methane stored in the liquid storage unit 3a is taken out, and the supply amount of LNG to the packed bed 20 can be increased more quickly by decreasing the bypass flow rate. Although the response delay occurs, the flow rate of the liquefied methane introduced into the packed bed 20 is more stable than when no extraction (bypass) is performed. As illustrated in FIG. It was confirmed that the pressure increase within 20 could be significantly suppressed. Specifically, the pressure fluctuation range is suppressed from 1.77 bar to 1.16 bar (−34%) as compared with the case where there is no bypass. Also, the duration of the pressure disturbance was reduced from 20 minutes to 10 minutes (here, the duration of the disturbance was the time required for the pressure to return to 9.2 bar).
(Ii) When BOG suddenly decreases As illustrated in FIG. 5A, when the BOG flow rate decreases, the LNG flow rate is decreased correspondingly and the bypass flow rate is temporarily increased. As a result, the amount of LNG supplied to the packed bed 20 can be increased more quickly. Compared with the case where no bypass flow rate is flown at all, the flow rate of liquefied methane introduced into the packed bed 20 is more stable, and as shown in FIG. It was confirmed that it could be suppressed. Specifically, the pressure fluctuation was suppressed from 2.46 bar to 1.47 bar (−40%) and the duration of the pressure disturbance was suppressed from 33 minutes to 13 minutes compared to the case without bypass.

DESCRIPTION OF SYMBOLS 1 Gas introduction part 2 Liquid introduction part 3 Distributor 3a Liquid storage part 3b Liquid distribution hole 3c Gas distribution pipe part 4 Mixed liquid storage part 5 Mixed liquid storage part 6 Delivery pump 10 Upper stage part 10a Upper stage space 20 Packing layer 20a Upper space 30 of packed bed Lower stage G Gas component h Liquid level height L Liquid component M Mixed liquid R Reflux liquid S Lower liquid introduction part T Liquid extraction part V1 Flow rate adjustment part

Claims (4)

A gas introduction part into which the delivered gas component is introduced, a liquid introduction part into which the delivered liquid component is introduced, and a distribution part into which the introduced gas component and the liquid component are respectively distributed. An upper stage having,
The gas component and the liquid component distributed in the distribution unit are introduced in a dispersed manner, and the gas component is dissolved or condensed by gas-liquid contact to dissolve or condense the gas component and gas-liquid mixing,
A lower stage portion provided at a lower portion of the packed bed and having a mixed liquid storage portion for storing a mixed liquid that has been gas-liquid mixed and a mixed liquid supply portion for discharging the stored mixed liquid; ,
In the distribution unit, a liquid storage unit for storing the introduced liquid component, a plurality of liquid distribution holes provided at the bottom of the liquid storage unit for distributing the stored liquid component, and the stored liquid component A plurality of gas distribution pipe parts through which the gas component flows through the upper part space and the packed bed upper space in a non-contact manner, a liquid level gauge for detecting the liquid level of the liquid storage part, and the liquid level A liquid level adjustment unit for adjusting the height,
The liquid level adjustment unit has a liquid extraction unit from which a part of the liquid component stored in the liquid storage unit can be taken out and a flow rate adjustment unit of the liquid component, and the liquid level of the liquid storage unit is A gas-liquid mixing device controlled and adjusted according to the amount of liquid component taken out. A gas introduction part into which the delivered gas component is introduced, a liquid introduction part into which the delivered liquid component is introduced, and a distribution part into which the introduced gas component and the liquid component are respectively distributed. An upper stage having,
The gas component and the liquid component distributed in the distribution unit are introduced in a dispersed manner, and the gas component is dissolved or condensed by gas-liquid contact to dissolve or condense the gas component and gas-liquid mixing,
A lower stage portion provided at a lower portion of the packed bed and having a mixed liquid storage portion for storing a mixed liquid that has been gas-liquid mixed and a mixed liquid supply portion for discharging the stored mixed liquid; ,
In the distribution unit, a liquid storage unit for storing the introduced liquid component, a plurality of liquid distribution holes provided at the bottom of the liquid storage unit for distributing the stored liquid component, and the stored liquid component A plurality of gas distribution pipe parts through which the gas component flows through the upper part space and the packed bed upper space in a non-contact manner, a liquid level gauge for detecting the liquid level of the liquid storage part, and the liquid level A liquid level adjustment unit for adjusting the height,
The liquid level adjustment unit has been extracted from a liquid extraction unit from which a part of the liquid component stored in the liquid storage unit can be extracted, a flow rate adjustment unit of the liquid component, and a flow rate adjustment unit of the extraction amount A reflux unit that recirculates a part of the liquid component to the liquid storage unit again, and a flow rate adjustment unit for the reflux liquid, and the liquid level of the liquid storage unit is recirculated and returned to the liquid component A gas-liquid mixing device controlled and adjusted by a reflux flow rate of a liquid component. A gas-liquid mixing method in which a supplied gas component and a liquid component are brought into gas-liquid contact using a packed bed, and the gas component is dissolved or condensed in the liquid component to be gas-liquid mixed. 1) In the upstream stage of the packed bed, the introduced gas component and liquid component are each distributed by a distributor,
(2) In the packed bed in which the distributed gas component and liquid component are dispersedly introduced, gas-liquid mixing is performed;
(3) In the downstream stage of the packed bed, the gas-liquid mixed liquid mixture is stored, and the stored liquid mixture is supplied,
(4) In the distribution unit, the introduced liquid component is stored in the liquid storage unit, and the stored liquid component is distributed by a plurality of liquid distribution holes provided at the bottom of the liquid storage unit. The upstream stage is introduced into the packed bed, and the introduced gas component is in non-contact with the liquid component stored via a plurality of gas distribution pipe portions provided in proximity to the liquid storage portion. Is introduced into the packed bed from the space of
(5) A part of the liquid component stored in the liquid storage part is taken out, and a liquid surface height of the liquid storage part is controlled / adjusted by an amount of the liquid component taken out. Gas-liquid mixing method. A gas-liquid mixing method in which a supplied gas component and a liquid component are brought into gas-liquid contact using a packed bed, and the gas component is dissolved or condensed in the liquid component to be gas-liquid mixed. 1) In the upstream stage of the packed bed, the introduced gas component and liquid component are each distributed by a distributor,
(2) In the packed bed in which the distributed gas component and liquid component are dispersedly introduced, gas-liquid mixing is performed;
(3) In the downstream stage of the packed bed, the gas-liquid mixed liquid mixture is stored, and the stored liquid mixture is supplied,
(4) In the distribution unit, the introduced liquid component is stored in the liquid storage unit, and the stored liquid component is distributed by a plurality of liquid distribution holes provided at the bottom of the liquid storage unit. The upstream stage is introduced into the packed bed, and the introduced gas component is in non-contact with the liquid component stored via a plurality of gas distribution pipe portions provided in proximity to the liquid storage portion. Is introduced into the packed bed from the space of
(5) A part of the liquid component stored in the liquid storage part is taken out, and a part of the taken out liquid component is recirculated to the liquid storage part, and the liquid level of the liquid storage part is A gas-liquid mixing method characterized by being controlled and adjusted by the amount of liquid component taken out and the reflux flow rate of the liquid component to be refluxed.

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