KR20130005467A - Liquid cargo storage equipment - Google Patents

Abstract

PURPOSE: A liquid cargo storage tank is provided to reduce volatile organic compound according to pressure drop at the top of a vertical pipe when loading liquid cargo because the pressure at the top of the vertical pipe is rapidly reached to a vapor pressure. CONSTITUTION: A liquid cargo storage tank(100) comprises first and second liquid cargo storage tanks(111,112), an auxiliary tank(160), an upper horizontal pipe(120), a vertical pipe(130), a lower horizontal pipe(140), a third outlet(143), and first to third control valves(151,152,153). The first and second liquid cargo tanks are formed in both sides of a barrier(114). The auxiliary tank penetrates through the barrier. The half of the auxiliary tank is positioned in the first liquid cargo storage tank and the rest half thereof is positioned in the second liquid cargo storage tank. The upper horizontal pipe is horizontally arranged above the first and second liquid cargo storage tanks. The vertical pipe is extended downward from the upper horizontal pipe in a vertical direction. The lower horizontal pipe is extended from the bottom of the vertical pipe to the inside of the second liquid cargo storage tank through the first liquid cargo storage tank and the auxiliary tank.

Description

Liquid cargo storage equipment

The present invention relates to a liquid storage device, and more particularly, to a liquid storage device configured to reduce the volatile organic compounds generated in the vertical pipe when loading the liquid in the liquid storage tank.

Onshore or offshore crude oil production facilities, crude oil storage facilities, refinery facilities or crude oil carriers are provided with liquid cargo storage tanks for storing relatively high vapor pressure liquids such as crude oil, petroleum, liquefied gases or other mineral liquids. When loading a liquefied liquid in such a liquefied storage tank, a considerable amount of volatile organic compounds (hereinafter referred to as VOCs) are generated from the liquefied liquid.

In particular, the VOC is generated a lot in the vertical pipe when the liquid cargo is loaded. For example, a crude oil carrier has a crude oil storage tank for storing crude oil, pipes for loading crude oil in a crude oil storage tank, horizontal pipes disposed horizontally on top of the crude oil storage tank, and vertically extending vertically downward from the horizontal pipes. Crude oil storage facilities including piping are provided. The crude oil supplied through the horizontal pipe drops sharply by gravity in the vertical pipe, and excessive pressure drop occurs at the upper end of the vertical pipe. At this time, the upper end pressure in the vertical pipe is lower than the vapor pressure, and thus VOC is generated from crude oil at the upper end in the vertical pipe.

The generated VOC contains various organic compounds, which are harmful to the human body, and when released into the atmosphere, cause smog, causing air pollution. Specifically, VOCs are highly mobile in the atmosphere, cause odors, have potential toxicity and carcinogenic properties, and because they form ozone by photochemical reactions with nitric oxide and other compounds, The situation is particularly focused. In addition, when the VOC generated in this way is discharged into the atmosphere, the loss of a liquefied product such as crude oil occurs.

Therefore, it is necessary to reduce the generation of VOC when loading the liquid cargo in the liquid cargo storage tank and to suppress the discharge of the VOC.

Embodiments of the present invention provide a liquid storage device having a configuration that can reduce the volatile organic compounds generated in the vertical pipe when loading the liquid in the liquid storage tank.

According to an aspect of the present invention,

First and second liquefied storage tanks adjacent to each other with a partition therebetween; An auxiliary tank installed through the partition wall, one of which is located inside the first liquid storage tank, and the other of which is located inside the second liquid storage tank: based on the partition wall Two upper horizontal pipes arranged horizontally on top of the liquid cargo storage tank; A vertical pipe extending vertically downward from the upper horizontal pipe; A lower horizontal pipe extending horizontally from the lower end of the vertical pipe through the first liquid storage tank and the auxiliary tank to the inside of the second liquid storage tank; A first outlet disposed in the lower horizontal pipe, the first outlet disposed inside the first liquid storage tank, the second outlet disposed inside the second liquid storage tank, and a third outlet disposed inside the auxiliary tank; And first, second, and third control valves installed at the first, second, and third outlets, respectively.

The liquid cargo supplied through the lower horizontal pipe fills the auxiliary tank through the third outlet, and then flows into the first and second liquid cargo storage tanks by overflowing an upper end of the auxiliary tank. A liquid cargo storage facility is provided.

In addition, a lower end of the auxiliary tank is closely attached to the bottom surfaces of the first and second liquid cargo storage tanks, and an upper end of the auxiliary tank includes a first upper outlet and a second upper outlet for discharging the liquid cargo in the auxiliary tank. The first and second upper outlets may be located at both sides of the partition wall, respectively.

In addition, the first and second upper outlets may be provided with first and second upper valves to control the discharge of the liquid cargo, respectively.

In addition, a case surrounding the top and side surfaces of the auxiliary tank is installed outside the auxiliary tank at intervals from the auxiliary tank, and the liquid cargo overflowing the top of the auxiliary tank between the case and the auxiliary tank. Flowing internal passages may be formed.

In addition, a first lower outlet and a second lower outlet may be formed at a lower end of the case for discharging the liquid cargo flowing through the inner passage.

In addition, based on the partition wall, the first lower outlet may be formed on the first liquid storage tank side, the second lower outlet may be formed on the second liquid cargo storage tank side.

In addition, a plurality of gas outlets may be formed at the top of the case.

In addition, the auxiliary tank may have a shape that gradually narrows from the bottom to the top.

In addition, a plurality of guide grooves extending from the upper end to the lower end of the auxiliary tank may be formed on the outer surface of the auxiliary tank.

In addition, a cover covering an upper end of the auxiliary tank may be disposed at an upper portion of the auxiliary tank at intervals from an upper end of the auxiliary tank.

In addition, the middle portion of the cover may have a flat plate shape, the outer peripheral portion may have a shape bent downward.

In addition, the cover may be supported by being fixed to the partition wall.

In addition, the height of the auxiliary tank may be equal to or greater than the height of the liquefied liquid such that the pressure of the upper end in the vertical pipe is equal to or higher than the vapor pressure of the liquefied liquid.

In addition, the cross-sectional area of the auxiliary tank may be wider than the cross-sectional area of the lower horizontal pipe.

In addition, the first, second and third outlets may protrude downward.

In addition, a concave guide may be formed at the bottom of the auxiliary tank to guide the flow of the liquid cargo flowing into the auxiliary tank through the third outlet.

In addition, the third outlet of the lower horizontal pipe may protrude upward.

In addition, the lower portion of the lower horizontal pipe is formed in the lower portion of the height lowering portion is bent in a "U" shape, the height is lowered, the height lower portion penetrates the auxiliary tank, the third lower portion is formed in the lower portion Can be.

In addition, an auxiliary outlet for discharging the liquid cargo in the auxiliary tank is formed at the lower end of the auxiliary tank, the auxiliary outlet may be provided with an auxiliary valve for opening and closing the auxiliary outlet.

According to the liquid storage device according to the embodiments of the present invention, since the liquid is first filled in the auxiliary tank installed in the liquid storage tank, the hydrostatic pressure according to the height of the liquid in the auxiliary tank extends in the vertical pipe, vertical pipe The upper pressure in the inner reaches the vapor pressure in a faster time. Therefore, the occurrence of VOC due to a sudden pressure drop at the upper end in the vertical pipe during the loading of the liquid can be reduced. And, since one auxiliary tank is shared by two liquid cargo storage tanks, the structure can be simplified and the installation cost can be reduced.

1 is a view showing the configuration of a liquid storage device equipped with VOC reduction means according to an embodiment of the present invention.
FIG. 2 is a view for explaining a process of loading a liquefied liquid after the liquefied liquid is filled in the auxiliary tank in the liquefied storage device shown in FIG. 1.
3 is a view showing a state when unloading the liquid in the liquid storage tank in the liquid storage device shown in FIG.
4 is a view showing an example in which the case is installed outside the auxiliary tank in the liquid cargo storage facility shown in FIG.
5 is a view showing the configuration of a liquid storage device equipped with VOC reduction means according to another embodiment of the present invention.
FIG. 6 is a perspective view illustrating an auxiliary tank of the liquid cargo storage facility illustrated in FIG. 5.
FIG. 7 is a view illustrating an example in which a cover is installed on an auxiliary tank in the liquid cargo storage facility illustrated in FIG. 5.
8 is a view showing a modification of the lower horizontal pipe and the third outlet in the liquid cargo storage facility shown in FIG.

Hereinafter, with reference to the accompanying drawings will be described a liquid storage device equipped with VOC reduction means according to embodiments of the present invention. In the drawings, the same reference numerals denote the same elements.

1 is a view showing the configuration of a liquid storage device equipped with VOC reduction means according to an embodiment of the present invention.

Referring to FIG. 1, a liquid liquefaction for storing relatively high vapor pressure liquids such as crude oil, petroleum, liquefied gas, or other mineral liquefied liquids in onshore or offshore crude oil production facilities, crude oil storage facilities, refinery facilities, or crude oil carriers Storage facility 100 is provided.

The liquid storage device 100, the liquid storage tanks 111 and 112 for storing the liquid, and the pipes 120 for loading the liquid in the liquid storage tanks (111, 112) , 130, 140). The pipes 120, 130, and 140 may include upper horizontal pipes 120 disposed horizontally on the liquid storage tanks 111 and 112 and vertically downwardly extending from the upper horizontal pipes 120. It includes a vertical pipe 130, and the lower horizontal pipe 140 for connecting the vertical pipe 130 and the liquid cargo storage tank (111, 112). For example, when the liquid storage device 100 is provided in the crude oil carrier, the upper horizontal pipe 120 is connected to the crude oil storage tank of the crude oil production site, through which the crude oil is supplied. The liquid cargo supplied through the upper horizontal pipe 120 is introduced into the liquid cargo storage tanks 111 and 112 through the vertical pipe 130 and the lower horizontal pipe 140.

As described above, when the liquid cargo is loaded into the liquid storage tanks 111 and 112, the pressure falls below the vapor pressure by acceleration due to gravity at the upper end portion (part A) of the vertical pipe 130. The phenomenon occurs, which causes a lot of VOCs.

In general, when the liquid level in the liquid storage tanks 111 and 112 is increased while the liquid level is filled in the liquid storage tanks 111 and 112, the fluid static pressure corresponding to the height of the liquid storage liquid is increased in the vertical pipe ( Since it is also extended to 130, the pressure of the upper end portion A in the vertical pipe 130 is also increased. At this time, when the pressure of the upper end portion A in the vertical pipe 130 is greater than or equal to the vapor pressure of the liquid, the generation of VOC is rapidly reduced. As such, the height of the liquefied liquid in the liquefied storage tanks 111 and 112 such that the pressure of the upper end portion A of the vertical pipe 130 is equal to or higher than the vapor pressure of the liquefied liquid is referred to as a critical level.

However, as described above, since the time required for the height of the liquefied liquid to reach the critical height in the liquefied storage tanks 111 and 112 is considerably long, a considerable amount of VOC is generated during that time. Therefore, when the time required for the liquid level to reach the critical height in the liquid storage tanks 111 and 112 is reduced, that is, the pressure of the upper end A in the vertical pipe 130 is greater than or equal to the vapor pressure of the liquid. Reducing the time required to reduce the occurrence of VOC can be reduced.

To this end, the liquid storage device 100 according to an embodiment of the present invention, the auxiliary tank (installed between the first and second liquid storage tanks 111 and 112 adjacent to each other with the partition 113 therebetween ( 160).

In addition, the lower horizontal pipe 140 penetrates through the first liquid storage tank 111 and the auxiliary tank 160 from the lower end of the vertical pipe 130 to form an interior of the second liquid storage tank 112. Extends horizontally until. The lower horizontal pipe 140 is provided with three outlets 141, 142, and 143 for discharging the liquid cargo. The first outlet 141 is disposed inside the first liquid cargo storage tank 111. The second outlet 142 is disposed inside the second liquid cargo storage tank 112, and the third outlet 143 is disposed inside the auxiliary tank 160. The first, second, and third outlets 141, 142, and 143 may all protrude downward. In addition, the first, second, and third outlets 141, 142, and 143 are provided with first, second, and third control valves 151, 152, and 153 for regulating the discharge of the liquid cargo.

Specifically, the auxiliary tank 160 may have a vertically erect tubular shape and may also have a circular cross-sectional shape, but is not limited thereto and may have various cross-sectional shapes such as a quadrangle or a polygon. The auxiliary tank 160 is vertically installed between the first and second liquid cargo storage tanks 111 and 112. That is, the auxiliary tank 160 is installed to pass through the partition wall 113 between the first and second liquid storage tanks 111 and 112 in a vertical position. Accordingly, the auxiliary tank 160 is located within the first liquid cargo storage tank 111 and the other side is located inside the second liquid cargo storage tank 112 based on the partition wall 113. do.

A lower end of the auxiliary tank 160 is closely attached to the bottom surfaces of the first and second liquid cargo storage tanks 111 and 112, and a first end of the auxiliary tank 160 for discharging the liquid cargo inside the auxiliary tank 160. An upper outlet 161 and a second upper outlet 162 are formed. The first and second upper outlets 161 and 162 are disposed at both sides of the partition wall 113, respectively. Specifically, based on the partition wall 113, the first upper outlet 161 is formed at the side of the first liquid cargo storage tank 111, and the second upper outlet 172 is the second liquid cargo storage tank 112. ) Is formed on the side. The first upper outlet 161 and the second upper outlet 162 may be provided with a first upper valve 163 and a second upper valve 164 to control the discharge of the liquid cargo, respectively.

As described above, the lower horizontal pipe 140 is installed to penetrate the auxiliary tank 160 horizontally. Liquid cargo is introduced into the auxiliary tank 160 through the third outlet 143 of the lower horizontal pipe 140. In order to smoothly flow the liquid cargo, the bottom of the auxiliary tank 160 is provided. The concave guide 165 may be provided to guide the flow of the liquefied product.

The auxiliary tank 160 has a constant height (H), the height (H) is the height of the liquid cargo so that the pressure of the upper end (part A) in the vertical pipe 130 is more than the vapor pressure of the liquid cargo , Ie, equal to or greater than the critical height.

The cross-sectional area of the auxiliary tank 160 should be larger than the cross-sectional area of the lower horizontal pipe 140, but the range may be appropriately determined in consideration of the following matters.

If the cross-sectional area of the auxiliary tank 160 is too small, since the smooth flow of liquid cargo in the auxiliary tank 160 may be disturbed, the lower limit of the cross-sectional area of the auxiliary tank 160 may be determined in consideration of this. have. On the contrary, if the cross-sectional area of the auxiliary tank 160 is too large, the time for reaching the above-mentioned critical height of the liquid level in the auxiliary tank 160 becomes long, so that the VOC in the vertical pipe 130 is increased. Since the reduction effect may be lowered, the upper limit of the cross-sectional area of the auxiliary tank 160 may be determined in consideration of this.

When loading liquid cargo in the first and second liquid cargo storage tanks 111 and 112, first, the third control valve 153 installed at the third outlet 143 of the lower horizontal pipe 140 is opened, The first and second control valves 151 and 152 provided at the first and second outlets 141 and 142 remain closed. Then, the liquid cargo supplied through the lower horizontal pipe 140 is introduced into the auxiliary tank 160 through the third outlet 143, so that the height of the auxiliary tank 160 is increased inside the auxiliary tank 160. Up to (H) first, and thereafter overflows through the first and second upper outlets 161, 162 of the auxiliary tank 160 to fill the interior of the first and second liquefied storage tanks 111, 112. Filled up. At this time, the first and second upper valves 163 and 164 installed in the first and second upper outlets 161 and 162 of the auxiliary tank 160 are kept open.

Meanwhile, the first and second upper valves 163 and 164 may be kept open together as described above, but are not limited thereto. That is, only one of the first and second upper valves 163 and 164 may be kept open, and in this case, only one of the first and second liquid cargo storage tanks 111 and 112 may be loaded with the liquid cargo. can do. In addition, the first and second upper valves 163 and 164 may be sequentially opened, and in this case, the liquid cargo may be sequentially loaded into the first and second liquid cargo storage tanks 111 and 112.

As described above, since the liquefied liquid supplied through the lower horizontal pipe 140 fills the inside of the auxiliary tank 160 first, the height of the liquefied liquid in the auxiliary tank 160 is quickly increased, and thus the liquefied liquid The hydrostatic pressure of the liquefied liquid corresponding to the height of the extends to the inside of the vertical pipe 130 through the lower horizontal pipe 140, so that the pressure of the upper end (A) in the vertical pipe 130 is also rapidly increased. When the liquefied liquid in the auxiliary tank 160 reaches the height H of the auxiliary tank 160, the upper end pressure in the vertical pipe 130 reaches the vapor pressure of the liquefied liquid. Will decrease. Therefore, the occurrence of VOC due to a sudden pressure drop in the upper end portion A in the vertical pipe 130 may be reduced when loading the liquefied liquid.

In addition, the auxiliary tank 160 is not installed in the first and second liquid cargo storage tanks 111 and 112, respectively, and only one auxiliary tank 160 is installed and shared, thereby simplifying the structure and reducing the installation cost. Can be.

FIG. 2 is a view for explaining a process of loading a liquefied liquid after the liquefied liquid is filled in the auxiliary tank in the liquefied storage device shown in FIG. 1.

Referring to FIG. 2, the liquefied liquid having overflowed the upper end of the auxiliary tank 160 through the first and second upper outlets 161 and 162 may be the first and second liquefied storage tanks 111 and 112. As the interior is filled, the height of the liquefied liquid in the first and second liquid liquefied storage tanks 111 and 112 also gradually increases to reach the height of the auxiliary tank 160. In this process, since the height of the liquid liquefied in the auxiliary tank 160 is kept constant, a constant fluid static pressure is applied to the lower horizontal pipe 140 and the vertical pipe 130. Therefore, the flow rate of the liquid cargo flowing into the first and second liquid cargo storage tanks 111 and 112 through the lower horizontal pipe 140 can be kept constant, so that the control of the liquid cargo loading process is easy. There is this.

When the height of the liquid liquefied in the first and second liquid liquefied storage tank (111, 112) reaches the height of the auxiliary tank 160, the third installed in the third outlet 143 of the lower horizontal pipe 140 Close the control valve 153 and open the first and second second control valves (151, 152) installed in the first and second outlets (141, 142) to remove the liquid cargo supplied through the lower horizontal pipe 140 The first and second outlets 141 and 142 may be directly introduced into the first and second liquefied storage tanks 111 and 112. In this case, the liquefied liquid supplied through the lower horizontal pipe 140 may be more smoothly introduced into the first and second liquefied storage tanks 111 and 112. At this time, since the heights of the liquefied liquid in the first and second liquid liquefied storage tanks 111 and 112 have already reached the critical height, the pressure drop does not occur at the upper end portion A in the vertical pipe 130. .

On the other hand, when the height of the liquid liquefied in the first and second liquid liquefied storage tank (111, 112) reaches the height of the auxiliary tank 160, the agent installed in the third outlet 143 of the lower horizontal pipe 140 The control valve 153 is kept open, and the first and second control valves 151 and 152 provided at the first and second outlets 141 and 142 are also opened to be supplied through the lower horizontal pipe 140. The liquefied material may be introduced into the first and second liquefied storage tanks 111 and 112 through all of the first, second, and third outlets 141, 142, and 143.

In addition, even if the height of the liquid liquefied in the first and second liquid liquefied storage tanks 111 and 112 reaches the height of the auxiliary tank 160, it is provided in the third outlet 143 of the lower horizontal pipe 140 Only the third control valve 153 may be kept open, and the first and second control valves 151 and 152 installed at the first and second outlets 141 and 142 may remain closed. The liquefied material supplied through the lower horizontal pipe 140 is introduced into the first and second liquefied storage tanks 111 and 112 through the third outlet 143 and the auxiliary tank 160.

In the above, the case where the liquid cargo is simultaneously loaded into the first and second liquid cargo storage tanks 111 and 112 has been described as an example. However, the loading of the liquid cargo may be sequentially performed. For example, as described above, when only the first upper valve 163 provided at the upper end of the auxiliary tank 160 is opened and the second upper valve 164 is closed, the liquefied liquid in the auxiliary tank 160 is the first liquid phase. Only the cargo storage tank 111 is overflowed, so that the liquid cargo flows only into the first liquid cargo storage tank 111. When the height of the liquefied liquid in the first liquid liquefied storage tank 111 reaches the height of the auxiliary tank 160, the second control valve 152 is kept closed, the first control valve 151 is opened by The liquefied liquid is continuously introduced into the first liquid liquefied storage tank 111. In this case, only the third control valve 153 may be kept open or the first control valve 151 and the third control valve 153 may be opened together. After the loading of the liquid liquefied in the first liquid liquefied storage tank 111 is completed, the liquid liquefied may be loaded in the second liquid liquefied storage tank 112 in the same manner as described above. The order of loading the liquid cargo in the first liquid storage tank 111 and the second liquid storage tank 112 may be changed.

3 is a view showing a state when unloading the liquid in the liquid storage tank in the liquid storage device shown in FIG.

Referring to FIG. 3, the upper horizontal pipe 120, the vertical pipe 130, and the lower horizontal pipe 140 are disposed inside the first and second liquid cargo storage tanks 111 and 112 and the auxiliary tank 160. It can also be used for unloading loaded liquid cargo. In this case, all of the first, second, and third valves 151, 152, and 153 installed at the first, second, and third outlets 141, 142, and 143 of the lower horizontal pipe 140 are opened. . Then, the liquid liquefied inside the first and second liquid storage tanks 111 and 112 and the auxiliary tank 160 is connected to the lower horizontal pipe through the first, second and third outlets 141, 142 and 143. It may be introduced into the 140, it may be unloaded via the vertical pipe 130 and the upper horizontal pipe (120). At this time, as described above, since the first, second and third outlets 141, 142, and 143 protrude downward, the liquid phase near the bottom of the first and second liquefied storage tanks 111 and 112. The cargo and the liquid cargo near the bottom of the auxiliary tank 160 may also be smoothly discharged.

As described above, the first, second and third valves 151, 152 and 153 are opened at the same time to be loaded into the first and second liquid cargo storage tanks 111 and 112 and the auxiliary tank 160. The liquidate may be unloaded at the same time, but the unloading of the liquidate may proceed sequentially. For example, first, only the first valve 151 is opened to unload the liquefied liquid in the first liquefied storage tank 111, and then only the second valve 152 is opened to liquefied liquid in the second liquefied storage tank 112. Unloading, and finally, only the third valve 153 may be opened to unload the liquid cargo in the auxiliary tank 160. The order of opening the first, second and third valves 151, 152, 153 is not limited to the above, and any order may be possible.

In addition, as described above, the liquid cargo in the auxiliary tank 160 may be unloaded simultaneously or sequentially, but the liquid cargo in the auxiliary tank 160 may be maintained as it is for the next liquid cargo loading without being unloaded. In this case, the third control valve 153 is kept closed.

4 is a view showing an example in which the case is installed outside the auxiliary tank in the liquid cargo storage facility shown in FIG.

Referring to FIG. 4, a case 170 may be installed outside the auxiliary tank 160 to surround the top and side surfaces of the auxiliary tank 160 at a predetermined distance from the auxiliary tank 160. In this case, the lower horizontal pipe 140 also passes through the case 170.

The case 170 has a lower end supported on the bottom surfaces of the first and second liquid storage tanks 111 and 112, and an upper end thereof covers the upper end of the auxiliary tank 160. The case 170 may have a shape corresponding to that of the auxiliary tank 160. First and second lower outlets 171 and 172 for discharging the liquid cargo may be formed at the lower end of the case 170. Based on the partition 113, the first lower outlet 171 is formed at the first liquid storage tank 111, and the second lower outlet 172 is formed at the second liquid storage tank 112. do. A plurality of gas outlets 174 may be formed at an upper end of the case 170, and the plurality of gas outlets 174 may store VOCs generated in the first and second liquid cargo storage tanks 111 and 112. It will be discharged to the top.

By the above configuration, an internal passage 173 is formed in the space between the case 170 and the auxiliary tank 160. The liquefied liquid which overflowed the upper end of the auxiliary tank 160 flows down through the inner passage 173, and opens the first and second lower outlets 171 and 172 formed at the lower end of the case 170. It is discharged through and flows into the first and second liquid cargo storage tanks 111 and 112.

Liquid cargo that overflows the upper end of the auxiliary tank 160 may be scattered while falling vertically from the upper end of the auxiliary tank 160, and thus may evaporate and generate VOCs as the contact area with the surrounding air becomes wider. . However, as described above, when the case 170 is installed outside the auxiliary tank 160, the liquid cargo overflowing the upper end of the auxiliary tank 160 is the auxiliary tank 160 and the case 170. Since it flows down through the inner passage 173 formed therebetween, the scattering of the liquefaction is limited, the contact with the ambient air is minimized, and the generation of VOC can be suppressed.

5 is a view showing the configuration of a liquid storage device equipped with a VOC reduction means according to another embodiment of the present invention, Figure 6 is a perspective view showing an auxiliary tank of the liquid storage device shown in FIG.

5 and 6 together, the liquid storage device 200 according to another embodiment of the present invention, the first and second liquid storage tanks 111 and 112 adjacent to each other with the partition 113 therebetween. Auxiliary tank 260 provided between) is provided.

In addition, the lower horizontal pipe 140 penetrates through the first liquid storage tank 111 and the auxiliary tank 260 from the lower end of the vertical pipe 130 to the interior of the second liquid storage tank 112. Extends horizontally until. The lower horizontal pipe 140 is provided with three outlets 141, 142, and 143 for discharging the liquid cargo. The first outlet 141 is disposed inside the first liquid cargo storage tank 111. The second outlet 142 is disposed inside the second liquid cargo storage tank 112, and the third outlet 143 is disposed inside the auxiliary tank 260. The first, second and third control valves 151, 152 and 153 are provided at the first, second and third outlets 141, 142 and 143 to control the discharge of the liquid cargo.

The auxiliary tank 260 is installed to pass through the partition wall 113 between the first and second liquid storage tanks 111 and 112 in a vertical position. A lower end of the auxiliary tank 260 is closely supported on the bottom surfaces of the first and second liquid storage tanks 111 and 112, and a first end of the auxiliary tank 260 for discharging the liquid in the auxiliary tank 260. An upper outlet 261 and a second upper outlet 262 are formed. The first upper outlet 261 and the second upper outlet 262 are disposed at both sides of the partition wall 113, respectively. In addition, a first upper valve 263 and a second upper valve 264 may be installed in the first upper outlet 261 and the second upper outlet 262 to control the discharge of the liquid cargo. In addition, at the bottom of the auxiliary tank 260, in order to smoothly flow the liquid cargo flowing into the auxiliary tank 260 through the third outlet 143 of the lower horizontal pipe 140, a concave guide ( 265 may be provided.

The cross-sectional area of the auxiliary tank 260 is larger than the cross-sectional area of the lower horizontal pipe 140, and the height H is such that the pressure of the upper end (part A) in the vertical pipe 130 is equal to or greater than the vapor pressure of the liquid. It can be equal to or higher than the height of the liquefied liquid, ie the critical height.

The configuration of the liquid cargo storage facility 200 is the same as the liquid cargo storage facility 100 shown in FIG. 1 except for the shape of the auxiliary tank 260, and thus the operation and effect thereof are the same. Detailed description thereof will be omitted.

In the liquid storage device 200, the auxiliary tank 260 has a shape that gradually narrows from the lower end to the upper end. The cross section of the auxiliary tank 260 may have a substantially circular shape as shown in FIG. 6, but is not limited thereto and may have various shapes such as a rectangle or a polygon.

6, a plurality of guide grooves 266 extending from an upper end to a lower end of the auxiliary tank 260 may be formed on an outer surface of the auxiliary tank 260. The plurality of guide grooves 266 may be disposed at intervals along the outer circumference of the auxiliary tank 260.

As described above, the auxiliary tank 260 is gradually narrower from the lower end to the upper end, so that the outer surface of the auxiliary tank 260 is inclined. Therefore, since the liquefied liquid which overflows the upper end of the auxiliary tank 260 flows naturally along the inclined outer surface of the auxiliary tank 260 without falling vertically, the scattering of the liquefied liquid can be suppressed. And, since the liquefied liquid overflowing the upper end of the auxiliary tank 260 flows down along a plurality of guide grooves 266 formed on the outer surface of the auxiliary tank 260, the entire outer surface of the auxiliary tank 260. The contact between the liquefied liquid and the ambient air can be minimized as compared to the case of widespread flow. As such, in the process of flowing down the liquefied liquid overflowing the upper end of the auxiliary tank 260, the scattering of the liquefied liquid is suppressed, and the contact with the ambient air is minimized, the generation of VOC can be reduced.

FIG. 7 is a view illustrating an example in which a cover is installed on an auxiliary tank in the liquid cargo storage facility illustrated in FIG. 5.

Referring to FIG. 7, a cover 270 may be disposed on an upper portion of the auxiliary tank 260 to cover an upper end of the auxiliary tank 260 at a predetermined distance from an upper end of the auxiliary tank 260. The middle portion of the cover 270 may have a flat plate shape, and the outer circumferential portion may have a shape bent downward. The cover 270 may be fixed to and supported by the partition wall 113.

When the cross-sectional area of the upper end of the auxiliary tank 260 is narrow or the flow rate of the liquid cargo rapidly increases, the liquid cargo may be ejected and scattered through the first upper outlet 261 and the second upper outlet 262. As a result, the contact area with the surrounding air becomes wider and may evaporate to generate VOC. However, as described above, when the cover 270 is disposed on the auxiliary tank 260, the scattering of the liquid cargo is limited by the cover 270, and the contact with the ambient air is minimized. The occurrence of can be suppressed.

8 is a view showing a modification of the lower horizontal pipe and the third outlet in the liquid cargo storage facility shown in FIG.

First, referring to FIG. 1, when the third outlet 143 of the lower horizontal pipe 140 protrudes downward, the auxiliary tank 160 may be discharged by the liquid cargo discharged through the third outlet 143. The bottom surface may be eroded, and the flow of the liquid cargo is changed from downward to upward again, so that a guide 145 is required to smooth the flow.

However, as shown in FIG. 8, when the third outlet 143 of the lower horizontal pipe 140 protrudes upward, the liquid cargo discharged through the third outlet 143 faces upward. Therefore, the upward flow of the liquid cargo in the auxiliary tank 160 can be made smoothly. In addition, it is possible to prevent the erosion of the bottom surface of the auxiliary tank 160, there is also an advantage that does not require a guide (145 of FIG. 1).

In addition, a portion of the lower horizontal pipe 140 may be formed with a height lowering portion 145 having a lowered height by bending downward in a “U” shape, and the height lowering portion 145 may be the auxiliary tank 160. The through-holes may protrude from the height reduction portion 145 such that the third outlet 143 faces upward. Accordingly, the position of the third outlet 143 may be prevented from being excessively high.

As described above, the liquid cargo in the auxiliary tank 160 may be unloaded through the third outlet 143, but as the third outlet 143 is formed to protrude upward, the third outlet (143) The following liquids can be difficult to unload. In order to solve this problem, an auxiliary outlet 167 for discharging the liquid cargo may be formed at the lower end of the auxiliary tank 160. By discharging the liquefied liquid in the auxiliary tank 160 into the first or second liquid liquefied storage tanks 111 and 112 through the auxiliary discharge port 167, the liquid liquefied in the auxiliary tank 160 may be completely unloaded. Can be. In addition, the auxiliary outlet 167 may be provided with an auxiliary valve 168 for opening and closing the auxiliary outlet 167, the auxiliary valve 168 is maintained in a closed state when loading the liquid cargo, It will only open when the cargo is unloaded.

On the other hand, the modification of the lower horizontal pipe 140 and the third outlet 143, the auxiliary discharge port 167 formed in the lower end of the auxiliary tank 160 and the auxiliary valve 168 provided therein are shown in FIG. In addition to the illustrated embodiment, the present invention may be applied to the embodiments illustrated in FIGS. 4, 5, and 7.

Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Accordingly, the true scope of protection of the present invention should be defined by the appended claims.

100,200 ... Liquid storage system 111 ... First liquid storage tank
112 Second liquid cargo storage tank 113 Bulkhead
120.Top horizontal piping 130 ... Vertical piping
140 ... bottom horizontal piping 141 ... 1st outlet
142 ... Exit 2 143 ... Exit 3
145 ... height drop 151 ... first control valve
152 ... second control valve 153 ... third control valve
160,260 ... Secondary tank 161,261 ... First upper outlet
162,262 ... 2nd top outlet 163,263 ... 1st top valve
164,264 ... Second upper valve 165,265 ... Guide
167 Auxiliary outlet 168 Auxiliary valve
170 ... case 171 ... first lower outlet
172 2nd lower outlet 173 Internal passage
Gas outlet 266 Guide groove
270 ... cover

Claims (19)

First and second liquefied storage tanks adjacent to each other with a partition therebetween;
An auxiliary tank installed through the partition wall, one of which is located inside the first liquid storage tank, and the other of which is located inside the second liquid storage tank, based on the partition wall:
An upper horizontal pipe disposed horizontally above the first and second liquefied storage tanks;
A vertical pipe extending vertically downward from the upper horizontal pipe;
A lower horizontal pipe extending horizontally from the lower end of the vertical pipe through the first liquid storage tank and the auxiliary tank to the inside of the second liquid storage tank;
A first outlet disposed in the lower horizontal pipe, the first outlet disposed inside the first liquid storage tank, the second outlet disposed inside the second liquid storage tank, and a third outlet disposed inside the auxiliary tank; And
And first, second, and third control valves installed at the first, second, and third outlets, respectively.
The liquid cargo supplied through the lower horizontal pipe fills the auxiliary tank through the third outlet, and then flows into the first and second liquid cargo storage tanks by overflowing an upper end of the auxiliary tank. Liquid cargo storage equipment. The method of claim 1,
A lower end of the auxiliary tank is closely attached to the bottom surfaces of the first and second liquid cargo storage tanks, and a first upper outlet and a second upper outlet for discharging the liquid cargo inside the auxiliary tank are formed at an upper end thereof. And the first and second upper outlets are located at both sides of the partition wall, respectively. The method of claim 2,
The first and second upper outlet port is a liquid cargo storage facility, characterized in that the first and second upper valve for regulating the discharge of the liquid cargo, respectively. The method of claim 2,
A case surrounding the top and side surfaces of the auxiliary tank is installed outside the auxiliary tank at intervals from the auxiliary tank, and a liquid cargo overflowing the top of the auxiliary tank flows between the case and the auxiliary tank. An apparatus for reducing volatile organic compounds in a liquid storage tank, characterized in that an inner passage is formed. 5. The method of claim 4,
And a first lower outlet and a second lower outlet for discharging the liquid cargo flowing through the inner passage at the lower end of the case. 6. The method of claim 5,
The first lower outlet is formed on the side of the first liquid cargo storage tank, the second lower outlet is formed on the second liquid cargo storage tank side, based on the partition wall. 5. The method of claim 4,
Liquid storage device characterized in that a plurality of gas outlet is formed on the top of the case. The method of claim 2,
The auxiliary tank has a liquid cargo storage facility characterized in that it has a shape that gradually narrows from the bottom to the top. The method of claim 8,
Liquid storage device characterized in that the outer surface of the auxiliary tank is formed with a plurality of guide grooves extending from the upper end to the lower end of the auxiliary tank. The method of claim 8,
The upper portion of the auxiliary tank, the liquid cargo storage facility, characterized in that a cover for covering the top of the auxiliary tank spaced from the top of the auxiliary tank. The method of claim 10,
The intermediate portion of the cover has a flat plate shape, the outer peripheral portion has a liquid storage device, characterized in that the shape bent downward. The method of claim 10,
And the cover is fixed to and supported by the partition wall. The method according to any one of claims 1 to 12,
The height of the auxiliary tank is a liquid cargo storage facility, characterized in that more than the height of the liquid cargo so that the pressure of the upper end in the vertical pipe is more than the vapor pressure of the liquid cargo. The method according to any one of claims 1 to 12,
The cross-sectional area of the auxiliary tank is larger than the cross-sectional area of the lower horizontal pipe liquid storage device. The method according to any one of claims 1 to 12,
And said first, second and third outlets project downwardly. 16. The method of claim 15,
And a concave guide formed at the bottom of the auxiliary tank to guide the flow of the liquid cargo flowing into the auxiliary tank through the third outlet. The method according to any one of claims 1 to 12,
And a third outlet of the lower horizontal pipe protrudes upward. 18. The method of claim 17,
A portion of the lower horizontal pipe is formed with a height lowering portion having a lowered height by bending downward in a "U" shape, the height reducing portion penetrating the auxiliary tank, and the third outlet is formed with the height lowering portion. Liquid cargo storage equipment. 18. The method of claim 17,
An auxiliary outlet for discharging the liquid cargo in the auxiliary tank is formed at the lower end of the auxiliary tank, the auxiliary outlet is a liquid cargo storage facility, characterized in that the auxiliary valve for opening and closing the auxiliary outlet is installed.

Images