Device for filling a tank

Abstract

Device for filling a tank (10) with a product, in particular a liquefied gas product, comprising an upper filling valve (30) which can be arranged on a first filling line (24) connecting a product reservoir (16) to an upper filling opening (20) of the tank (10), and a lower filling valve (32) which can be arranged on a second filling line (28) connecting the product reservoir (16) to a lower filling opening (22) of the tank (10), characterized in that the device comprises a control valve (42) to which the tank pressure in the tank (10) is applied as a control variable, and which is connected via a first control line (36) to the upper filling valve (30) and via a second control line (40) to the lower filling valve (32), wherein the control valve (42) controls the upper filling valve (30) and the lower filling valve (32) in such a way as to fill the Tanks (10) controls that the tank pressure corresponds to a specified setpoint or setpoint range.

Description

[0001] The invention relates to a device for filling a tank with a product, in particular a liquefied gas product, comprising an upper filling valve which can be arranged on a first filling line connecting a product reservoir to an upper filling opening of the tank, and a lower filling valve which can be arranged on a second filling line connecting the product reservoir to a lower filling opening of the tank.

[0002] For example, cryogenically cooled gases such as LIN, LOX, and LAR are stored in liquid form in tanks. The correspondingly stored liquefied gas product is fed into subsequent production or supply processes. This often involves converting the liquefied gas product back to its original gas phase, which requires the addition of energy, particularly heating. The supply of liquefied gas products to production or supply processes must be very consistent and precise, especially because the technical process components supplied have very limited operating ranges for economic or technical reasons.

[0003] A key requirement in this regard is to maintain the product pressure in the storage tank as constant as possible at all times, whatever the tank's operating condition. The pressure in tanks filled with a liquefied gas product is largely determined by the temperature of the gas phase in the tank. Even with very good insulation, the liquefied gas product heats up, which both increases the tank pressure and, if filled with a colder product, can cause the tank pressure to change significantly. The removal of product from the tank regularly causes a drop in tank pressure, which also must be compensated for. Compensation is usually achieved using heat exchangers to supply energy to the stored product. For economic reasons, the heat exchangers are designed as precisely as possible for typical removal capacities and therefore have only slight excess capacity above a certain limit.

[0004] As already explained, filling a tank with a product, especially a cold liquefied gas product, leads to a change in the tank pressure. Such tanks are therefore typically filled from both the top and bottom. If the tank is filled from the top, the tank pressure drops. If, however, the tank is filled from the bottom, the tank pressure increases. This applies at least as long as the filling rate is not so high that a fountain in the tank penetrates the liquid phase into the gas phase, thereby significantly cooling the gas phase, which can lead to an overall drop in tank pressure.

[0005] For economic and environmental reasons, particularly with regard to energy consumption and potential emissions in the supply chain, it is desirable to fill the tank simultaneously from the top and bottom with minimal valve and pipe resistance. Typically, the ratio of the filling rate from the top to the filling rate from the bottom is manually adjusted by an operator to ensure that the tank pressure remains as constant as possible. Manual valve adjustments are based on the operator's observation, which is based on a pressure gauge reading and a tank marking indicating a nominal working pressure. The operator must continuously monitor the tank pressure and, if necessary, regulate the product supply.At the same time, the operator must monitor and, if necessary, operate a tank vehicle or the like containing the product reservoir, as well as a line connection between the product reservoir and the tank.

[0006] In this context, prolonged monitoring gaps in the various areas can occur. This results in a significant operator risk and, in practice, a consistent occurrence of operating errors, which can lead to undesirable changes in tank pressure. This, in turn, can cause very significant economic damage, for example, through a prolonged downtime of downstream production or supply processes or, in the medical sector, disruptions to a critical supply chain.

[0007] Based on the prior art explained above, the object of the invention is therefore to provide a device of the type mentioned at the outset with which economic damage or disruptions to the supply chain during the filling of a tank with a product can be avoided in a simple and reliable manner.

[0008] The invention solves the problem by independent claim 1. Advantageous embodiments can be found in the dependent claims, the description and the figures.

[0009] For a device of the type mentioned at the outset, the invention solves the problem in that the device comprises a control valve to which the tank pressure in the tank is applied as a control variable, and which is connected to the upper filling valve via a first control line and to the lower filling valve via a second control line, wherein the control valve controls the upper filling valve and the lower filling valve to fill the tank in such a way that the tank pressure corresponds to a predetermined setpoint or setpoint range.

[0010] The tank can be a stationary storage tank. However, it can also be a mobile tank, for example on a tank vehicle. The product reservoir containing the product to be filled into the tank can be a mobile tank, for example on a tank vehicle. However, it can also be a stationary storage tank. As explained, the tank to be filled can be filled with a liquefied gas product, in particular a cryogenic liquefied gas product, such as LIN, LOX, LAR, or LNG. Such a liquefied gas product is present in the tank in both the liquid and gaseous phases. The tank can be a single-walled low-temperature or normal-temperature tank, in particular a liquefied gas tank, or a double-walled tank, in particular a liquefied gas tank, for example a cryogenic tank. The same applies to the product reservoir.

[0011] The device according to the invention comprises a control valve to which the tank pressure in the tank is applied as the controlled variable during a filling process. The control valve is connected to the upper filling valve via a first control line and to the lower filling valve via a second control line, so that the control valve can control both the upper filling valve and the lower filling valve to fill the tank with the product. Controls are possible with different filling cross-sections, which are released by the respective filling valve. Accordingly, the filling rate of the tank from the top and from the bottom can be individually adjusted by the control valve. Of course, the control valve can also close the upper filling valve and / or the lower filling valve to completely interrupt the filling process.

[0012] The control valve according to the invention, which in particular forms a pilot valve, is particularly maintenance-free over the long term and is capable of automatically and precisely maintaining the tank pressure within a nominal working pressure range or, for example, interrupting further filling as a protective function if a limit value of the tank pressure is exceeded. In particular, the control valve controls the upper filling valve and the lower filling valve to fill the tank in such a way that the tank pressure corresponds to a predetermined setpoint or setpoint range, in particular with a defined tolerance above and below a fixed setpoint. To define an acceptable range around the setpoint, a control hysteresis can be specified, which can, for example, be in a range of plus / minus 0.5 bar. This prevents the valves from switching too frequently and thus an excessive demand for a control medium, such as a control gas or control air.

[0013] Thanks to the inventive design, the control valve can control the upper and lower filling valves for simultaneous filling from the top and bottom of the tank, provided the tank pressure applied to the control valve as a controlled variable is within the specified setpoint or setpoint range. In this way, the inflow is maximized by minimizing resistance. If the tank pressure exceeds the specified setpoint or setpoint range, the control valve can adjust the filling of the tank to a greater extent from the top or exclusively from the top by appropriately controlling the upper and lower filling valves. This leads to a reduction in the tank pressure.If, on the other hand, the tank pressure is below the specified setpoint or setpoint range, the control valve can control the upper and lower filling valves so that the tank is filled more intensively from the bottom, for example exclusively from the bottom, which generally increases the tank pressure again. If the product flow is too fast, so that an undesirable drop in tank pressure occurs despite the product already being supplied exclusively through the lower filling valve, the control valve can interrupt further filling of the tank. Further filling can then take place, for example, via an external signal line bypass, possibly with a reduced flow rate, provided the lower filling valve is equipped with an external limiter. It is also possible to open a reduced bypass filling line exclusively from the bottom.The control valve automatically resumes normal control operation as soon as a minimum tank pressure is reached again.

[0014] It is also possible to add additional switching points, for example, to achieve a progressively reduced filling from the bottom before the filling is shut off. This can be achieved either by detecting the slightly open position of a valve section or by continuously reducing the control medium, such as control air, as the differential pressure increases to a nominal working pressure.

[0015] If the tank pressure rises above a maximum pressure despite product already being supplied exclusively from the top, the control valve can also interrupt further filling from the top. The control valve can then automatically resume control operation as soon as the pressure falls below a maximum pressure again.

[0016] Overall, the invention makes it possible to avoid economic damage caused by prolonged downtime of subsequent production or supply processes or disruptions of a critical supply chain, for example in the medical sector, in a reliable and simple manner by automatically controlling the upper and lower filling valves via the control valve in such a way that the tank pressure does not leave a setpoint or setpoint range.

[0017] In a particularly practical design, the control valve can pneumatically control the upper and lower filling valves. This allows for particularly reliable and fast control, if necessary, independent of a power supply or an external control pressure supply.

[0018] The tank pressure in the tank can still be applied to an intermediate tank, and a control pressure of the control valve for pneumatically controlling the upper filling valve and the lower filling valve can be fed from the pressure in the intermediate tank. The control valve can generally be operated from an external pressure source, e.g. compressed air, or alternatively with a supplied, reserved tank gas phase. The control valve controls the upper and lower filling valves using the control gas. In particular, if the tank pressure via the intermediate tank is used as the control gas for the control valve, the valve can also operate completely independently, in particular in addition to a power supply and also with regard to an external pressure supply. This is particularly important for critical infrastructure, for example in the medical sector, for example for supplying hospitals with gases such as LOX and LIN.A regulator can be provided which brings the pressure used as control pressure, in particular the pressure provided from an external pressure source or the tank pressure, to a predetermined constant value for use as control pressure.

[0019] According to a further embodiment, it can be provided that the tank pressure applied to the control valve actuates a control shaft of the control valve in the axial direction, wherein two control elements are arranged on the control shaft, which control the upper filling valve and / or the lower filling valve for filling the tank depending on the axial position of the control shaft. The control elements can comprise control disks arranged on the control shaft. The control elements can form cams which, depending on the axial position of the control shaft, actuate, for example, pneumatic valves, which in turn actuate the upper or lower filling valve for filling the tank. The control valve can thus comprise a gate control for controlling the filling valves. The aforementioned embodiment achieves particularly simple automatic control of the filling valves.

[0020] According to a further embodiment, the control shaft may have an external thread, and the control elements may have an internal thread engaging with the external thread, so that the control elements can be arranged at different axial positions on the control shaft. In this way, the control valve can be adapted to different setpoints or setpoint ranges. In particular, the integrated spindle function of the shaft and the control elements allows for variably adjusting the switching points of the control valve.

[0021] According to a further embodiment, the tank pressure can actuate the control stem via a control bellows that expands in the axial direction of the control stem depending on the tank pressure. The elastic control bellows can be a metal bellows, preferably a stainless steel bellows. Such a control bellows can be used, for example, to specify a control hysteresis or a setpoint range. The use of a metal material, such as stainless steel, also has the advantage that such materials are permitted in corresponding pressure equipment, and the design of the control valve is characterized by a high degree of freedom from contamination risk.

[0022] According to a further embodiment, at least a section of the control shaft containing the control elements can be arranged in a housing of the control valve. The housing can form a protective housing. Furthermore, a spring device exerting counterpressure on the control bellows can be arranged between the control bellows and a section of the control shaft containing the control elements. The spring device can be supported on the one hand on the control bellows and on the other hand on the housing. The spring device can be formed by a plurality of springs inserted one inside the other in a cascade-like manner. The control shaft can extend through the spring device to the control bellows. The spring device can also be a metal spring device, preferably a stainless steel spring device.The spring device exerting counterpressure on the control bellows allows adjustment of the control valve, particularly for regulating the tank pressure to a predetermined setpoint range. The design of the spring device with a plurality of nested or cascaded springs enables a particularly compact design in the axial direction. This offers a significant advantage for the present applications. Since the spring device can also be manufactured from a metal material, such as stainless steel, the above-mentioned advantages regarding admissibility in pressure devices are achieved. The aforementioned configurations also allow a design in which functional areas in contact with the product do not require static and dynamic seals, particularly by combining the flexible control bellows with the aforementioned spring device.

[0023] According to a further embodiment, an adjusting element can be arranged on a side of the spring device facing away from the control bellows, with which a preload of the spring device can be adjusted. The adjusting element can comprise an adjusting screw with which the spring device can be compressed to adjust the preload. This integrated tensioning device allows the control valve to be set to the desired setpoint, in particular by an operator, and, if desired, secured against changes, for example, by sealing.

[0024] The device may also comprise a display device on which, for example, the set setpoint or setpoint range is displayed to an operator.

[0025] According to a further embodiment, it can be provided that the tank pressure is applied to the control valve via a pressure measuring line, and that a shut-off valve is arranged in the pressure measuring line, with which the pressure measuring line can be shut off, and that a test connection is provided between the shut-off valve and the control valve, to which a setting pressure for setting the control valve can be applied. By means of this embodiment, the pressure measuring line connecting the tank pressure as a controlled variable to the control valve can be shut off, so that a setting or calibration pressure for setting or calibrating the control valve can be applied via a test connection of the pressure measuring line. In this way, the control valve can also be calibrated or set to a specific setpoint or setpoint range independently of the tank and the tank pressure currently prevailing therein.

[0026] The invention also relates to a system comprising a tank to be filled with a product, in particular a liquefied gas product, and a product reservoir, as well as a device according to the invention. In the system according to the invention, the upper and lower filling valves are arranged on the first and second filling lines, respectively. As already explained, the tank can be a stationary storage tank and the product reservoir a tank arranged on a tank vehicle. However, an embodiment is also possible in which the tank is a mobile tank, for example a tank arranged on a tank vehicle, and / or in which the product reservoir is a stationary storage tank.

[0027] The invention also relates to a method for filling a tank with a product, in particular a liquefied gas product, using a device or a system according to the invention.

[0028] Embodiments of the invention are explained in more detail below with reference to the drawings. They show schematically: Fig. 1 a system according to the invention with a device according to the invention according to a first embodiment, Fig. 2 a control valve of the device according to the invention in a sectional view, and Fig. 3 a system according to the invention and a device according to the invention according to a second embodiment.

[0029] Unless otherwise stated, the same reference symbols in the figures refer to the same objects.

[0030] The Fig. The system illustrated in Figure 1 comprises a tank 10, in this case a stationary storage tank 10, which is filled with a liquefied gas product contained in the storage tank 10 in the liquid state up to a liquid level 12 and in the gas phase above that. A tank vehicle 14 has a product reservoir 16 in the form of a mobile tank 16, from which additional liquefied gas product is to be filled into the tank 10 via a supply line 18. For this purpose, the tank 10 comprises an upper filling opening 20 on its upper side and a lower filling opening 22 on its underside.

[0031] A first filling line 24 connects the product reservoir 16 via the supply line 18 and a manually operable shut-off valve 26, for example, to the upper filling opening 20. A second filling line 28 connects the product reservoir 16, also via the supply line 18 and the shut-off valve 26, to the lower filling opening 22. An upper filling valve 30 is arranged on the first filling line 24 and a lower filling valve 32 is arranged on the second filling line 28. The upper filling valve 30 has a first pneumatic control inlet 34, to which a first control line 36 is connected, and the lower filling valve 32 has a second pneumatic control inlet 38, to which a second control line 40 is connected.By controlling the upper filling valve 30 and the lower filling valve 32, the tank 10 can be filled with liquid gas product from the product reservoir 16 via the upper filling opening 20 from the top and via the lower filling opening 22 from the bottom, by the upper and lower filling valves 30, 32 opening or closing different flow cross sections of the first and second filling lines 24, 28, respectively.

[0032] The Fig. 1 shown system or the one in Fig. The device shown in Figure 1 further comprises a control valve 42 with a first control output 44 connected to the first control line 36 and a second control output 46 connected to the second control line 40. The tank pressure in the tank 10 is applied as a controlled variable to a pressure inlet 50 of the control valve 42 via a pressure measuring line 48. As explained in more detail below, the control valve 42, on the basis of the tank pressure received as a controlled variable, controls the upper filling valve 30 or the lower filling valve 32 via the first control line 36 and the second control line 40 to fill the tank 10 in such a way that the tank pressure corresponds to a predetermined setpoint or predetermined setpoint range.

[0033] The control pressure for pneumatically controlling the upper filling valve 30 and the lower filling valve 32 via the first and second control inputs 34, 38 is Fig. 1, the pressure is provided by an external compressed gas supply 52, in particular a compressed air supply 52. ​​A regulator 58 is arranged in the control pressure line 56 connecting the compressed gas supply 52 to the compressed gas inlet 54 of the control valve 42. This regulator regulates the control pressure to a predetermined value, for example, 6 bar. A pressure gauge 60 (Pressure Indicator PI) is also arranged on the pressure measuring line 48. A corresponding pressure gauge 62 (PI) is also arranged on the control pressure line 56. The tank pressure measured by the pressure gauge 60 and / or the control pressure measured by the pressure gauge 62 can be displayed to an operator via a display device of the device according to the invention.

[0034] A shut-off valve 64 is also arranged in the pressure measuring line 48, via which the connection to the tank 10 can be interrupted. A defined set pressure can be applied to the control valve 42, in particular the pressure inlet 50, via a test connection 66 and a connection valve 68 to adjust the control valve 42, in particular to a desired setpoint or setpoint range.

[0035] In Fig. 2 shows a sectional view of the control valve 42. The control valve 42 comprises a housing 70, on the underside of which a connection housing 72, for example a cylindrical one, is arranged. On the underside of the connection housing 72 is the pressure inlet 50, to which the pressure measuring line 48 is connected. The tank pressure applied via the pressure measuring line 48 acts on an elastic control bellows 74, which is compressed depending on the applied tank pressure. On the top side of the control bellows 74, a control shaft 76 is arranged, the upper section of which projects into the housing 70. Two control disks 78, 80 forming cams are arranged at an axial distance from one another on the section of the control shaft 76 arranged in the housing 70.The control shaft 76 has an external thread, at least in its upper section, and the control discs 78, 80 have a corresponding internal thread, so that they can be arranged in different axial positions on the control shaft 76 in the manner of a spindle drive. As the control bellows 74 expands or compresses, the control shaft 76 is moved in the axial direction, and with it the control discs 78, 80. These can, for example, actuate pneumatic valves (not shown in detail), which transmit the control pressure present at the compressed gas inlet 54 to actuate the first control inlet 34 of the upper filling valve 30 or the second control inlet 38 of the lower filling valve 32, in particular via the first control line 36 and the second control line 40.

[0036] In Fig. 2 also shows that a spring device 82 is supported on the upper side of the control bellows 74 on the one hand and the underside of the housing 70 on the other hand. This spring device is formed in particular by springs inserted into one another in a cascade-like manner and exerts a counterpressure on the elastic control bellows 74. The level of the counterpressure exerted by the spring device 82 can be adjusted by an adjusting element 84, for example, an adjusting screw 84. Both the elastic control bellows 74 and the spring device 82 can be made of a metal material, for example, stainless steel. This also applies to the other components of the control valve shown.

[0037] In Fig. 3 shows a further embodiment of a system or device according to the invention, which largely corresponds to the embodiment of Fig. 1 corresponds.

[0038] In contrast to the design according to Fig. 1, the control pressure applied to the compressed gas inlet 54 in the embodiment according to Fig. 3 is provided via the tank pressure. For this purpose, the tank pressure prevailing in the pressure measuring line 48 is applied to an intermediate tank 90 via an intermediate tank line 86 and a shut-off valve 88. The control pressure prevailing in the intermediate tank 90 is in this case applied to the control pressure line 56 via a valve 92. Advantage of the Fig. 3 is that the device according to the invention can operate independently, in particular independently of an external control pressure supply and a power supply. Reference symbol 10 tanks 12 liquid levels 14 tanker trucks 16 Product reservoir 18 supply line 20 Upper filling opening 22 Lower filling opening 24 First filling line 26 Shut-off valve 28 Second filling line 30 Upper filling valve 32 Lower filling valve 34 First control input 36 First control line 38 Second control input 40 Second control line 42 Control valve 44 First control output 46 Second control output 48 Pressure measuring line 50 pressure input 52 Compressed gas supply 54 Compressed gas inlet 56 Control pressure line 58 Regulator 60 pressure gauges 62 pressure gauges 64 Shut-off valve 66 test connection 68 connection valve 70 housings 72 connection housings 74 Control bellows 76 Tax office 78, 80 Controls 82 Spring device 84 Adjusting element 86 Intermediate tank line 88 Shut-off valve 90 intermediate tank 92 Valve

Claims

[1] Device for filling a tank (10) with a product, in particular a liquefied gas product, comprising an upper filling valve (30) which can be arranged on a first filling line (24) connecting a product reservoir (16) to an upper filling opening (20) of the tank (10), and a lower filling valve (32) which can be arranged on a second filling line (28) connecting the product reservoir (16) to a lower filling opening (22) of the tank (10), characterized by that the device comprises a control valve (42) to which the tank pressure in the tank (10) is applied as a control variable, and which is connected to the upper filling valve (30) via a first control line (36) and to the lower filling valve (32) via a second control line (40), wherein the control valve (42) controls the upper filling valve (30) and the lower filling valve (32) to fill the tank (10) in such a way that the tank pressure corresponds to a predetermined setpoint value or setpoint value range. [2] Device according to claim 1, characterized by that the control valve (42) pneumatically controls the upper filling valve (30) and the lower filling valve (32). [3] Device according to claim 2, characterized by that the tank pressure in the tank (10) continues to be applied to an intermediate tank (90), and that a control pressure of the control valve (42) for pneumatically controlling the upper filling valve (30) and the lower filling valve (32) is fed from the pressure in the intermediate tank (90). [4] Device according to one of the preceding claims, characterized by that the tank pressure applied to the control valve (42) actuates a control shaft (76) of the control valve (42) in the axial direction, wherein two control elements (78, 80) are arranged on the control shaft (76) which, depending on the axial position of the control shaft (76), control the upper filling valve (30) and / or the lower filling valve (32) for filling the tank (10). [5] Device according to claim 4, characterized by that the control elements comprise control discs (78, 80) arranged on the control shaft (76). [6] Device according to one of claims 4 or 5, characterized by that the control shaft (76) has an external thread, and that the control elements (78, 80) have an internal thread engaging with the external thread, so that the control elements (78, 80) can be arranged on the control shaft (76) in different axial positions thereon. [7] Device according to one of claims 4 to 6, characterized by that the tank pressure actuates the control shaft (76) via a control bellows (74) which expands in the axial direction of the control shaft (76) depending on the tank pressure. [8] Device according to claim 7, characterized by that the control bellows (74) is a metal bellows (74), preferably a stainless steel bellows (74). [9] Device according to one of claims 4 to 8, characterized bythat at least one section of the control shaft (76) having the control elements (78, 80) is arranged in a housing (70) of the control valve (42). [10] Device according to one of claims 7 to 9, characterized by that a spring device (82) exerting a counterpressure on the control bellows (74) is arranged between the control bellows (74) and a section of the control shaft (76) having the control elements (78, 80). [11] Device according to claims 9 and 10, characterized by that the spring device (82) is supported on the control bellows (74) on the one hand and on the housing (70) on the other hand. [12] Device according to one of claims 10 or 11, characterized by that the spring device (82) has a plurality of nested springs. [13] Device according to one of claims 10 to 12, characterized by that the control shaft (76) extends through the spring device (82) to the control bellows (74). [14] Device according to one of claims 10 to 13, characterized by that the spring device (82) is a metal spring device (82), preferably a stainless steel spring device (82). [15] Device according to one of claims 10 to 14, characterized by that an adjusting element (84) is arranged on a side of the spring device (82) facing away from the control bellows (74), with which a preload of the spring device (82) can be adjusted. [16] Device according to one of the preceding claims, characterized by that the tank pressure is applied to the control valve (42) via a pressure measuring line (48), and that a shut-off valve (64) is arranged in the pressure measuring line (48), with which the pressure measuring line (48) can be shut off, and that a test connection (66) is provided between the shut-off valve (64) and the control valve (42), to which a setting pressure for setting the control valve (42) can be applied. [17] System comprising a tank (10) to be filled with a product, in particular a liquefied gas product, and a product reservoir (16) and a device according to one of the preceding claims. [18] System according to claim 17, characterized by that the tank (10) is a stationary storage tank (10), and that the product reservoir (16) is a tank (16) arranged on a tank vehicle.

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