Liquid Metal Metering Valve

Abstract

In one embodiment, a liquid metal pump is disclosed. The liquid metal pump includes a metal-side platen including a liquid metal cavity, an air-side platen including an air cavity, a diaphragm, a liquid metal inlet port, a metal outlet port, a plurality of heating coils, and a shuttle. The diaphragm is disposed between the metal-side platen and the air-side platen at an interface between the metal-side platen and the air-side platen. The diaphragm separates the liquid metal cavity from the air cavity. The shuttle is attached to the diaphragm and configured to actuate the diaphragm between an open position and a closed position.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to liquid metal pumps. In particular, embodiments of the present disclosure relate to metering valves for liquid alkali metals. [Background technology]

[0002] Rechargeable electrochemical storage systems are becoming increasingly important in many areas of daily life. High-capacity energy storage devices are being used in an increasing number of applications, including portable electronics, medicine, transportation, grid-connected bulk energy storage, renewable energy storage, and uninterruptible power supplies (UPS). In each of these applications, the charge / discharge time and capacity of the energy storage device are key parameters. In addition, the size, weight, and / or cost of such energy storage devices are also key parameters. Furthermore, low internal resistance is essential for high performance. The lower the internal resistance, the fewer limitations an energy storage device faces in delivering electrical energy. For example, in the case of batteries, internal resistance affects performance by reducing the total amount of useful energy stored by the battery and the battery's ability to deliver high currents.

[0003] Alkali metals are believed to have the best potential for achieving the desired capacity and cycling. However, there is currently no effective means of transporting liquid alkali metals within battery manufacturing machines. Conventional devices are unable to accurately meter the required volume of alkaline liquid metal due to their dependency on pressure differential. Furthermore, the use of conventional seals exposes the system to contamination from air and water due to the corrosive nature of liquid alkali metals and the high temperatures involved in maintaining the alkali metals in liquid form.

[0004] Therefore, there is a need for improved apparatus for pumping liquid alkali metals, and in particular for improved apparatus for metering liquid alkali metals. Summary of the Invention

[0005] The present disclosure relates generally to apparatus for liquid metal pumps. In particular, the apparatus disclosed herein relates to a metering valve for liquid alkali metals.

[0006] In one embodiment, a liquid metal pump is disclosed. The liquid metal pump includes a metal-side platen including a liquid metal cavity, an air-side platen including an air cavity, a diaphragm, a liquid metal inlet port, a metal outlet port, a plurality of heating coils, and a shuttle. The diaphragm is disposed between the metal-side platen and the air-side platen at an interface between the metal-side platen and the air-side platen. The diaphragm separates the liquid metal cavity from the air cavity. The shuttle is attached to the diaphragm and configured to actuate the diaphragm between an open position and a closed position.

[0007] In another embodiment, a liquid metal pump is disclosed. The liquid metal pump includes a metal-side platen including a first liquid metal cavity and a second liquid metal cavity, a first air-side platen including a first air cavity, a second air-side platen including a second air cavity, a first diaphragm, a second diaphragm, a liquid metal inlet port, a metal outlet port, a plurality of heating coils, and a shuttle. The first diaphragm is disposed between the metal-side platen and the first air-side platen at an interface between the metal-side platen and the first air-side platen. The first diaphragm separates the first liquid metal cavity from the first air cavity. The second diaphragm is disposed between the metal-side platen and the second air-side platen at an interface between the metal-side platen and the second air-side platen. The second diaphragm separates the second liquid metal cavity from the second air cavity. The shuttle is attached to the diaphragm and is configured to actuate the diaphragm between an open position and a closed position.

[0008] In yet another embodiment, a controller for a liquid metal pumping system is disclosed. The controller stores instructions that, when executed by a processor, cause the system to actuate a shuttle from a closed position to an open position, flow liquid metal into a first liquid metal cavity through a metal inlet port, actuate the shuttle from the open position to the closed position, and supply air to a first air cavity to flow liquid metal out of the first liquid metal cavity through a metal outlet port. A first diaphragm is disposed at an interface between the metal-side platen and the first air-side platen, between the first air cavity and the first metal cavity. The first diaphragm separates the first liquid metal cavity from the first air cavity.

[0009] So that the above-listed features of the present disclosure can be understood in detail, a more particular description of the present disclosure briefly outlined above may be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only exemplary embodiments of the present disclosure and therefore should not be considered limiting of the scope, since the present disclosure may embrace other equally effective embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view of a liquid metal pump according to the prior art; [Figure 2] 1 is a schematic cross-sectional view of a liquid metal pump according to an embodiment of the present disclosure; FIG. [Figure 3] 1 is a schematic cross-sectional view of a liquid metal pump according to an embodiment of the present disclosure; FIG. [Figure 4] 1 is a schematic cross-sectional view of a liquid metal pump according to an embodiment of the present disclosure; FIG. [Figure 5] 1 is a schematic cross-sectional view of a liquid metal pump according to an embodiment of the present disclosure; FIG. [Figure 6] FIG. 1 is a control schematic for use in a liquid metal pump according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] For ease of understanding, where possible, identical reference numerals have been used to designate identical elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without additional description.

[0012]

[0003] Embodiments of the present disclosure generally relate to liquid metal pumps. Specifically, embodiments of the present disclosure relate to metering valves for liquid alkali metals. In one embodiment, a liquid metal pump is disclosed. The liquid metal pump includes a metal-side platen including a liquid metal cavity, a first air-side platen including an air cavity, a diaphragm, a liquid metal inlet port, a metal outlet port, a plurality of heating coils, and a shuttle. The diaphragm is disposed between the metal-side platen and the air-side platen at an interface between the metal-side platen and the first air-side platen. The diaphragm separates the liquid metal cavity from the air cavity. The shuttle is attached to the diaphragm and configured to actuate the diaphragm between an open position and a closed position.

[0004] In another embodiment, a liquid pump is shown and described herein.

[0013] FIG. 1 is a schematic cross-sectional view of a prior art liquid metal pump 100 for pumping liquid metal. The liquid metal pump 100 includes a liquid metal container 102, an air inlet port 104, a metal outlet port 106, and a heating element 108. The liquid metal container holds a volume of liquid metal 110. In one embodiment, the liquid metal 110 is an alkali liquid metal. In one embodiment, the alkali liquid metal is one of lithium, sodium, potassium, and cesium. The liquid metal container 102 is vacuum-sealed to prevent exposure of the liquid metal 110 to contaminants such as air or water. The heating element 108 surrounds the sides and bottom of the liquid metal container 102 to heat the liquid metal container 102. The heating element 108 heats the liquid metal container 102 to between about 180° C. and about 200° C. to maintain the liquid metal 110 in liquid form. However, other temperatures that maintain the metal in a liquid state are contemplated. If the temperature is below 180° C., the liquid metal 110 may solidify, thereby impeding the flow of the liquid metal 110 .

[0014] To pump the liquid metal 110 from the liquid metal container 102, a gas is pumped through the air inlet port 104 to apply pressure 112 to the liquid metal 110. This creates a high-pressure system within the liquid metal container 102, forcing the liquid metal 110 towards the metal outlet port 106. In one embodiment, the gas pumped into this system is a non-reactive gas. In one embodiment, the non-reactive gas is one of argon, helium, and nitrogen. The high pressure of this gas creates a pressure differential between the liquid metal container 102 and the components of the liquid metal pump 100 downstream of the metal outlet port 106.

[0015] However, prior art liquid metal pumps 100 are unable to effectively meter the volume of the flow of liquid metal 110 passing through the liquid metal pump 100. Because the liquid metal pump 100 relies on the use of a pressure differential, rapid changes in pressure can result in overpumping or underpumping of the liquid metal 110, which leads to fluctuations in the volume of liquid metal 110 flowing through the liquid metal pump 100. Therefore, there is a need for improved apparatus for pumping liquid alkali metals, and in particular, improved apparatus for metering liquid alkali metals.

[0016] 2 is a schematic cross-sectional view of a liquid metal pump 200. The liquid metal pump 200 includes a metal-side platen 202 and an air-side platen 204. The liquid metal pump 200 also includes a diaphragm 206 disposed between the metal-side platen 202 and the air-side platen 204 at their interface. The metal-side platen 202 further includes an inlet valve 210, an outlet valve 212, a liquid metal cavity 214, and a first seal cavity 216 for receiving a first seal 217 (e.g., an O-ring or other gasket) therein. In one embodiment, the inlet valve 210 and the outlet valve 212 are check valves, each including a ball 218. The inlet valve 210 and the outlet valve 212 extend through the metal-side platen 202, and the inlet valve 210 and the outlet valve 212 are spaced apart from each other. In one example, the inlet valve 210 and the outlet valve 212 are oriented parallel to each other and / or perpendicular to the plane of the diaphragm 206. The ball 218 prevents liquid flow through the check valve, depending on the configuration of the check valve. The check valve of the inlet valve 210 allows liquid to enter the liquid metal cavity 214 and prevents liquid from exiting the liquid metal cavity 214. The check valve of the outlet valve 212 prevents liquid from entering the liquid metal cavity 214 but allows liquid to exit the liquid metal cavity 214. The inlet valve 210 and the outlet valve 212 are at approximately the same pressure, i.e., + / - 5 Torr. Liquid metal flows into the liquid metal cavity 214 through the inlet valve 210 and flows out of the liquid metal cavity 214 through the outlet valve 212. To facilitate sealing between the metal side platen 202 and the air side platen 204 , the first seal cavity 216 receives a first seal 217 .

[0017] The air-side platen 204 further includes an air cavity 220 adjacent to the diaphragm 206, a shuttle 222, a plurality of heating coils 224, and a second seal cavity 226 for receiving a second seal 227 (e.g., an O-ring or other gasket) therein. The shuttle 222 moves up and down within the shuttle cavity 228 perpendicular to the plane of the diaphragm 206. The heating coil 224 heats the metal-side platen 202 and the air-side platen 204 to maintain the liquid metal in liquid form at a temperature between about 180°C and about 200°C. However, other temperatures are contemplated. To facilitate uniform heating, the heating coil 224 is disposed in a plane parallel to the plane of the diaphragm 206. It is also contemplated that the heating coil 224 may be a single coil, or alternatively, the heating coil 224 may be replaced with a heating channel configured to receive a heating medium therein. The temperature generated by the heating coil 224 is controlled using a controller 620.

[0018] The diaphragm 206 spans both the liquid metal cavity 214 and the air cavity 220, separating the liquid metal in the liquid metal cavity 214 from the air in the air cavity 220. The liquid metal cavity 214 and the air cavity 220 are vacuum sealed using a first seal 217 and a second seal 227. The first seal 217 is received in the first seal cavity 216, and the metal-side platen 202 is secured over and in contact with the air-side platen 204 to clamp the diaphragm 206 in place. In one embodiment, the first seal 217 is formed using a gasket made of a soft metal and a knife edge to create a knife-edge seal. In one embodiment, the knife-edge seal is created by inserting a knife edge into the soft metal gasket and then securing the metal-side platen 202 over and in contact with the air-side platen 204. Pressure applied by metal side platen 202, which is fixed above and in contact with air side platen 204, creates a seal against liquid metal cavity 214 and air cavity 220. In one embodiment, the knife edge is steel and the gasket is copper.

[0019] Second seal 227 is received in second seal cavity 226 to provide a secondary seal. After placing second seal 227 in second seal cavity 226, metal-side platen 202 is secured below and in contact with air-side platen 204. By securing metal-side platen 202 below and in contact with air-side platen 204, second seal 227 is compressed within second seal cavity 226, thus creating a secondary seal. In one embodiment, second seal 227 is an o-ring made of a heat-resistant material such as ethylene propylene diene monomer (EPDM), a fluoropolymer elastomer (e.g., Viton™, Aflas™, Kalrez™), silicone, fluorosilicone, polyacrylate, or one of a combination thereof.

[0020] The shuttle 222 is connected to the diaphragm 206. In one embodiment, the shuttle 222 is made of stainless steel. The shuttle 222 is connected to the diaphragm 206 using a washer located on the side of the diaphragm 206 that faces the liquid metal cavity 214. The shuttle 222 and washer are connected using a thread. This allows the shuttle 222 to drive the diaphragm 206 either upward or downward, depending on the application. When liquid metal flows into the liquid metal cavity 214 through the inlet valve 210, the diaphragm 206 is pushed toward the bottom surface of the air-side platen 204, driving the shuttle 222 upward within the shuttle cavity 228. When the shuttle cavity 228 is driven upward within the shuttle cavity 228, air in the air cavity is released. As liquid metal enters liquid metal cavity 214 , outlet valve 212 prevents the liquid metal from exiting liquid metal cavity 214 until a sufficient amount of pressure is applied to ball 218 .

[0021] After the liquid metal cavity 214 is filled with liquid metal, air pressure pushes the shuttle 222 downward within the shuttle cavity 228. The air pressure is supplied by an air pressure source 219. In one embodiment, the air driving the shuttle 222 is heated, for example, to a temperature of approximately 180°C to 200°C. However, other temperatures are contemplated. The use of heated air facilitates uniform temperature control of the liquid metal pump 200. The shuttle 222 pushes downward on the diaphragm 206, forcing air into the air cavity 220. The downward movement on the diaphragm 206 exerts pressure on the liquid metal in the liquid metal cavity 214, which activates the ball 218 of the outlet valve 212, causing the liquid metal to flow out of the liquid metal cavity 214. The ball 218 of the inlet valve 210 prevents the liquid metal from flowing through the inlet valve 210. Each pump cycle pumps a predetermined volume of liquid metal, for example, about 0.5 ccm, allowing for a metered flow of liquid metal. Alternatively, it is contemplated that other volumes may be pumped depending on process considerations and diaphragm size. In some examples, the maximum pressure of the liquid metal in liquid metal cavity 214 is limited to avoid activating check valves in inlet valve 210 and outlet valve 212. The volume of liquid metal pumped into liquid metal cavity 214 (and therefore the pressure exerted by the liquid metal on diaphragm 206) and the pressure exerted by pneumatic pressure source 219 on shuttle 222 (and therefore diaphragm 206) are controlled using controller 620, described in FIG. 6 . In another embodiment, controller 620 can directly control the operation of shuttle 222.

[0022] 3 is a schematic cross-sectional view of a liquid metal pump 300. Liquid metal pump 300 is similar to liquid metal pump 200, except that liquid metal pump 300 has an air-side platen 304 with an air inlet port 366 and an air outlet port 368, and a metal-side platen 302 with at least one shuttle. Liquid metal pump 300 also includes a diaphragm 306 disposed between and at the interface between the metal-side platen 302 and the air-side platen 304. Metal-side platen 302 further includes a metal inlet port 310, a metal outlet port 312, a liquid metal cavity 314, a metal-side top shuttle 350, a metal-side bottom shuttle 352, a metal-side spring 354, and a first seal cavity 316 for receiving a first seal 317 (e.g., an O-ring or other gasket) therein. In another embodiment, the metal side top shuttle 350 and the metal side bottom shuttle 352 are replaced with a single metal side shuttle. Liquid metal enters the liquid metal cavity 314 through the metal inlet port 310 and exits the liquid metal cavity 314 through the metal outlet port 312. The first seal cavity 316 receives a first seal 317, which will be described in further detail herein.

[0023] The air-side platen 304 further includes an air cavity 320, an air-side top shuttle 360, an air-side bottom shuttle 362, an air-side spring 364, an air inlet port 366, an air outlet port 368, and a second seal cavity 326 for receiving a second seal 327 (e.g., an O-ring or other gasket) therein. In another embodiment, the air-side top shuttle 360 ​​and the air-side bottom shuttle 362 are replaced with a single air-side shuttle. In another embodiment, the air-side platen includes multiple heating coils. The heating coils heat the metal-side platen 302 and the air-side platen 304 to maintain the liquid metal in liquid form at between about 180°C and about 200°C. However, other temperatures are also contemplated. To facilitate uniform heating, the heating coils are positioned in a plane parallel to the plane of the diaphragm 306. It is also contemplated that the heating coil may be a single coil, or alternatively, the heating coil may be replaced with a heating channel configured to receive a heating medium therein. The temperature produced by the heating coil is controlled using a controller 620 .

[0024] Diaphragm 306 spans both liquid metal cavity 314 and air cavity 320, separating the liquid metal in liquid metal cavity 314 from the air in air cavity 320. Connectors 340 connect metal side top shuttle 350, metal side bottom shuttle 352, air side top shuttle 360, and air side bottom shuttle 362 to diaphragm 306. Connectors 340 move the diaphragm up or down based on the configuration of metal side top shuttle 350, metal side bottom shuttle 352, air side top shuttle 360, and air side bottom shuttle 362. Connectors 340 are operated by controller 620, described in FIG. 6 .

[0025] The liquid metal cavity 314 and the air cavity 320 are vacuum sealed using a first seal 317 and a second seal 327. The first seal 317 is received in the first seal cavity 316, and the air-side platen 304 is secured over and in contact with the metal-side platen 302 to clamp the diaphragm in place. In one embodiment, the first seal 317 is formed using a gasket made of a soft metal and a knife edge to create a knife-edge seal. In one embodiment, the knife-edge seal is created by inserting the knife edge into the soft metal gasket and then securing the air-side platen 304 over and in contact with the metal-side platen 302. The pressure applied by the air-side platen 304 secured over and in contact with the metal-side platen 302 creates a vacuum seal for the liquid metal cavity 314 and the air cavity 320. In one embodiment, the knife edge is steel and the gasket is copper. A second seal 327 is received in the second seal cavity 326 to provide a secondary seal. After placing the second seal 327 in the second seal cavity 326, the air-side platen 304 is secured over and in contact with the metal-side platen 302. By securing the air-side platen 304 over and in contact with the metal-side platen 302, the second seal 327 is compressed within the second seal cavity 326, thus creating a secondary vacuum seal. In one embodiment, the second seal 327 is an o-ring made of a heat-resistant material such as ethylene propylene diene monomer (EPDM), a fluoropolymer elastomer (e.g., Viton™, Aflas™, Kalrez™), silicone, fluorosilicone, polyacrylate, or a combination thereof.

[0026] In one embodiment, the metal side top shuttle 350 and the metal side bottom shuttle 352 are configured to mate with each other. Similarly, the air side top shuttle 360 ​​and the air side bottom shuttle 362 are configured to mate with each other. Each of the metal side shuttles 350, 352 and the air side shuttles 360, 362 is movable between an open position and a closed position. When the metal side shuttles 350, 352 are in the open position, the air side shuttles 360, 362 are in the closed position. When in the open position, the metal side shuttles 350, 352 allow liquid metal to flow into the liquid metal cavity 314 through the metal inlet port 310 and prevent liquid metal from flowing out of the liquid metal cavity 314 through the metal outlet port 312. While the air-side shuttles 360, 362 are in the open position, they allow air to enter the air cavity 320 through the air inlet port 366 and prevent air from exiting the air cavity 320 through the air outlet port 368. While in the closed position, the metal-side shuttles 350, 352 allow liquid metal to exit the metal outlet port 312 and prevent liquid metal from entering the liquid metal cavity 314 through the metal inlet port 310. While in the closed position, the air-side shuttles 360, 362 allow air to exit the air cavity 320 through the air outlet port 368 and prevent air from entering the air cavity 320 through the air inlet port 366.

[0027] The metal-side springs 354 and air-side springs 364 actuate the metal-side shuttles 350, 352 and the air-side shuttles 360, 362 between open and closed positions. The actuation of the metal-side springs 354 and air-side springs 364 is controlled by the controller 620. While the metal-side shuttles 350, 352 are in the open position, liquid metal flows into the liquid metal cavity 314 through the metal inlet port 310. The metal outlet port 312 is closed by the metal-side top shuttle 350, preventing liquid metal from flowing through the metal outlet port 312. While the liquid metal flows into the liquid metal cavity 314, the diaphragm 306 moves upward toward the bottom surface of the air-side platen 304. Furthermore, the actuation of the metal-side shuttles 350, 352 and the air-side shuttles 360, 362 drives the connector 340 upward, which in turn drives the diaphragm 306 upward. The upward movement of the diaphragm 306 forces air out of the air cavity 320 through the air outlet port 368. The air-side shuttles 360, 362 prevent air from entering the air cavity 320 through the air inlet port 366.

[0028] After the liquid metal cavity 314 is filled with liquid metal, the metal-side spring 354 and the air-side spring 364 actuate the metal-side shuttles 350, 352 to the closed position and the air-side shuttles 360, 362 to the open position. The actuation of the metal-side spring 354 and the air-side spring 364 is controlled by the controller 620. Air pressure pushes the diaphragm 306 downward toward the top surface of the metal-side platen 302. The air pressure is supplied from the air pressure source 319. In one embodiment, the air driving the shuttle 322 is heated, for example, to a temperature of approximately 180°C to 200°C. However, other temperatures are also contemplated. The use of heated air facilitates uniform temperature control of the liquid metal pump 300. The air outlet port 368 is closed by the air-side top shuttle 360. Actuation of the metal-side shuttles 350, 352 and the air-side shuttles 360, 362 drives the connector 340 downward, which in turn drives the diaphragm 306 downward. Actuation of the connector 340 is controlled by the controller 620. The downward movement of the diaphragm 306 forces liquid metal out of the liquid metal cavity 314 through the metal outlet port 312.

[0029] The liquid metal pump 300 allows for independent pressures at the metal inlet port 310 and the metal outlet port 312, allowing the liquid metal pump 300 to be used to move liquid metal from a high-pressure component to a low-pressure component, from a low-pressure component to a high-pressure component, or from an isobaric component. Furthermore, the metal-side platen 302 within the liquid metal pump 300 has a maximum pressure of up to approximately 100 psi. The use of the connector 340 allows the liquid metal pump 300 to effectively meter the volume of liquid metal because the liquid metal pump 300 does not rely on a pressure differential. Each pump cycle pumps a predetermined volume of liquid metal, e.g., approximately 0.5 ccm, allowing for a metered flow of liquid metal. Alternatively, pumping other volumes is contemplated depending on process considerations and membrane size. The volume of liquid metal pumped into the liquid metal cavity (and therefore the pressure exerted by the liquid metal in the liquid metal cavity) as well as the pressure exerted by the air pressure source 319 are controlled using a controller 620 .

[0030] 4 is a schematic cross-sectional view of a liquid metal pump 400. The liquid metal pump 400 is similar to the liquid metal pump 300, except that the liquid metal pump 400 has an air-side spring 464 instead of a shuttle on the air-side platen 404. The liquid metal pump 400 includes a metal-side platen 402 and an air-side platen 404. The liquid metal pump 400 also includes a diaphragm 406 disposed between the metal-side platen 402 and the air-side platen 404 at the interface between the metal-side platen 402 and the air-side platen 404. The metal-side platen 402 further includes a metal inlet port 410, a metal outlet port 412, a metal-side top shuttle 450, and an optional metal-side bottom shuttle, multiple heating coils 424, a liquid metal cavity 414, and a first seal cavity 416 for receiving a first seal 417 (e.g., an O-ring or other gasket) therein. In another embodiment, the metal-side top shuttle 450 and the metal-side bottom shuttle are replaced with a single metal-side shuttle. The heating coil 424 heats the metal-side platen 402 and the air-side platen 404 to maintain the liquid metal in liquid form at between about 180°C and about 200°C. However, other temperatures are contemplated. To facilitate uniform heating, the heating coil 424 is disposed in a plane parallel to the plane of the diaphragm 406. It is also contemplated that the heating coil 424 may be a single coil, or alternatively, the heating coil 424 may be replaced with a heating channel configured to contain a heating medium therein. The temperature generated by the heating coil 424 is controlled using a controller 620.

[0031] The air-side platen 404 includes an air cavity 420, an air inlet port 466, an air outlet port (not shown), an air-side spring 464, and a second seal cavity 426 for receiving a second seal 327 (e.g., an o-ring or other gasket) therein. A first seal 417 is received in the first and second seal cavities 416, 426 to provide a seal. In one embodiment, the second seal cavity 426 receives the second seal.

[0032] The diaphragm 406 spans both the liquid metal cavity 414 and the air cavity 420, separating the liquid metal in the liquid metal cavity 414 from the air in the air cavity 420. A connector 440 connects the metal-side top shuttle 450 and the air-side spring 464 to the diaphragm 406. The connector 440 moves the diaphragm 406 up or down based on the configuration of the metal-side top shuttle 450 and the air-side spring 464. The connector 440 and the air-side spring 464 are actuated by the controller 620.

[0033] The liquid metal cavity 414 and the air cavity 420 are vacuum sealed using a first seal 417. After placing the first seal 417 in the first and second seal cavities 416, 426, the metal-side platen 402 is secured over and in contact with the air-side platen 404. By securing the metal-side platen 402 over and in contact with the air-side platen 404, the first seal 417 is compressed within the first and second seal cavities 416, 426, thus creating a vacuum seal. In one embodiment, the first seal 417 is an o-ring made of a heat-resistant material such as ethylene propylene diene monomer (EPDM), a fluoropolymer elastomer (e.g., Viton™, Aflas™, Kalrez™), silicone, fluorosilicone, polyacrylate, or one of a combination thereof. In one embodiment, first seal 417 is formed using a gasket made of a soft metal and a knife edge to create a knife edge seal. In one embodiment, the knife edge seal is created by inserting the knife edge into the soft metal gasket and then securing the metal side platen 402 over and in contact with the air side platen 404. Pressure applied by the metal side platen 402 secured over and in contact with the air side platen 404 creates a vacuum seal against liquid metal cavity 414 and air cavity 420. In one embodiment, the knife edge is steel and the gasket is copper.

[0034] In one embodiment, the metal-side shuttle 450 and the air-side spring 464 are movable between an open position and a closed position. When the metal-side shuttle 450 is in the open position, the air-side spring 464 is in the closed position. While in the open position, the metal-side shuttle 450 allows liquid metal to flow into the liquid metal cavity 414 from the metal inlet port 410 and prevents liquid metal from flowing out of the liquid metal cavity 414 through the metal outlet port 412. While in the closed position, the metal-side shuttle 450 allows liquid metal to flow out of the liquid metal cavity 414 through the metal outlet port 412 and prevents liquid metal from flowing into the liquid metal cavity 414 through the metal inlet port 410.

[0035] The air-side spring 464 actuates the metal-side shuttle 450 between the open and closed positions. The actuation of the air-side spring is controlled by the controller 620. While the metal-side shuttle 450 is in the open position, liquid metal (not shown) flows into the liquid metal cavity 414 through the metal inlet port 410. The metal outlet port 412 is closed by the metal-side top shuttle 450. While the liquid metal flows into the liquid metal cavity 414, the diaphragm 406 moves downward toward the top surface of the air-side platen 404. Furthermore, the actuation of the air-side spring 464 drives the connector 440 downward, which in turn drives the diaphragm 406 downward. The downward movement of the diaphragm 406 forces air out of the air cavity 420 through the air outlet port.

[0036] When the metal-side shuttle 450 is in the closed position, the metal inlet port is closed and the metal outlet port is open. Air flows into the air cavity 420, causing the diaphragm 406 to move upward toward the bottom surface of the metal-side platen 402. Air pressure is supplied from an air pressure source 419. In one embodiment, the air driving the shuttle 422 is heated air, for example, to a temperature of approximately 180°C to 200°C. However, other temperatures are contemplated. The use of heated air facilitates uniform temperature control of the liquid metal pump 400. Additionally, actuation of the air-side spring 464 drives the connector 440 upward, which in turn drives the diaphragm 406 downward. The upward movement of the diaphragm 406 forces liquid metal out of the liquid metal cavity 414 through the metal outlet port 412.

[0037] The liquid metal pump 400 allows for independent pressures at the metal inlet port 410 and the metal outlet port 412, allowing the liquid metal pump 400 to be used to move liquid metal from a high-pressure component to a low-pressure component, from a low-pressure component to a high-pressure component, or from an isobaric component. Furthermore, the metal-side platen 402 within the liquid metal pump 400 has a maximum pressure of up to approximately 100 psi. The use of the connector 440 and air-side spring 464 allows the liquid metal pump 400 to effectively meter the volume of liquid metal because the liquid metal pump 400 does not rely on a pressure differential. Each pump cycle pumps a predetermined volume of liquid metal, for example, approximately 0.5 ccm of liquid metal, allowing for a metered flow of liquid metal. Alternatively, pumping other volumes is contemplated depending on process considerations and membrane size. The volume of liquid metal pumped into the liquid metal cavity (and therefore the pressure exerted by the liquid metal in the liquid metal cavity) as well as the pressure exerted by the air pressure source 419 are controlled using a controller 620 .

[0038] 5 is a schematic cross-sectional view of a liquid metal pump 500. The liquid metal pump 500 is similar to the liquid metal pump 400, but has two air-side platens and two diaphragms. The liquid metal pump 500 includes a metal-side platen 502, a top air-side platen 504A, and a bottom air-side platen 504B. The liquid metal pump 500 further includes a top diaphragm 506A disposed between the metal-side platen 502 and the top air-side platen 504A at the interface between the metal-side platen 502 and the top air-side platen 504A, and a bottom diaphragm 506B disposed between the metal-side platen 502 and the bottom air-side platen 504B at the interface between the metal-side platen 502 and the bottom air-side platen 504B. The metal side platen 502 further includes a metal inlet port 510, a metal outlet port 512, a shuttle 522 disposed within a shuttle cavity 528, a top liquid metal cavity 514A, a bottom liquid metal cavity 514B, and a liquid metal cavity connector 515. Liquid metal flows into the top liquid metal cavity 514A, the liquid metal cavity connector 515, and the bottom liquid metal cavity 514B through the metal inlet port 510 and flows out of the top liquid metal cavity 514A, the liquid metal cavity connector 515, and the bottom liquid metal cavity 514B through the metal outlet port 512. The liquid metal inlet port 510 and the liquid metal outlet port 512 are in selective fluid communication with the shuttle cavity 528. The top metal side seal cavity 516A and the bottom metal side seal cavity 516B of the metal side platen house a first seal 517 (eg, an o-ring or other gasket) therein.

[0039] The top air side platen 504A further includes an air inlet port 566, a plurality of top heating coils 524A, a top air cavity 520A, and a top air side platen seal cavity 526A. The bottom air side platen 504B further includes an air outlet port 568, a plurality of bottom heating coils 524B, a bottom air cavity 520B, and a bottom air side platen seal cavity 526B. An air cavity connector (not shown) allows air to flow from the top air cavity 520A to the bottom air cavity 520B. In one embodiment, the air inlet port 566 and the air outlet port 568 are operable between open and closed positions using check valves. In another embodiment, the air inlet port 566 and the air outlet port 568 are operable between open and closed positions using spring valves. The spring valves can be operated manually using set screws or can be operated using the controller 620. Heating coils 524A, 524B heat the metal side platen 502, the top air side platen 504A, and the bottom air side platen 504B to maintain the liquid metal in liquid form between about 180° C. and about 200° C. If the temperature is below 180° C., the liquid metal may solidify. The temperature generated by the heating coils 524A, 524B is controlled using a controller 620.

[0040] Top metal-side seal cavity 516A receives first seal 517A, and top air-side platen seal cavity 526A receives first seal 527A. Bottom metal-side seal cavity 516B receives second seal 517B, and bottom air-side seal cavity 526B receives second seal 527B. First seals 517A, 517B and second seals 527A, 527B create vacuum seals within cavities 514A, 514B, 520A, and 520B. In one embodiment, first seal 517A, 517B or second seal 527A, 527B are formed using a gasket made of soft metal and a knife edge to create a knife-edge seal. In one embodiment, a knife-edge seal is created by inserting a knife edge into a soft metal gasket, then clamping the top air-side platen 504A over and in contact with the metal-side platen 502 and the bottom air-side platen 504B over and in contact with the bottom air-side platen 504B. In one embodiment, the knife edge is steel and the gasket is copper. In one embodiment, the first seal 517A, 517B or the second seal 527A, 527B is an o-ring made of a heat-resistant material such as ethylene propylene diene monomer (EPDM), a fluoropolymer elastomer (e.g., Viton™, Aflas™, Kalrez™), silicone, fluorosilicone, polyacrylate, or one of a combination thereof. Pressure applied by the top air side platen 504A, which is fixed on top of and in contact with the metal side platen 502, and the metal side platen 502, which is fixed on top of and in contact with the bottom air side platen 504B, creates a vacuum seal for the top and bottom liquid metal cavities 514A, 514B and the top and bottom air cavities 520A, 520B.

[0041] Top diaphragm 506A extends across both top liquid metal cavity 514A and top air cavity 520A, separating the liquid metal in top liquid metal cavity 514A from the air in top air cavity 520A. Bottom diaphragm 506B extends across both bottom liquid metal cavity 514B and bottom air cavity 520B, separating the liquid metal in bottom liquid metal cavity 514B from the air in bottom air cavity 520B.

[0042] The shuttle 522 operates between an open position and a closed position. The operation of the shuttle 522 is controlled by the controller 620. When the shuttle 522 is in the open position, the shuttle 522 allows liquid to enter the top liquid metal cavity 514A through the metal inlet port 510 and to exit the bottom liquid metal cavity 514B through the metal outlet port 510. The metal inlet port 512 is closed by the shuttle 522. While liquid metal is flowing into the bottom liquid metal cavity 514B, the bottom diaphragm 506B moves downward toward the top surface of the bottom air-side platen 504B. While liquid metal is flowing into the top liquid metal cavity 514A, the top diaphragm 506A moves upward toward the bottom surface of the top air-side platen 504A. This movement of top and bottom diaphragms 506A, 506B causes air within top and bottom air cavities 520A, 520B to escape through air outlet port 568.

[0043] When shuttle 522 is in the closed position, it allows liquid metal to flow out of top liquid metal cavity 514A, through liquid metal cavity connector 515, and into bottom liquid metal cavity 514B. Air flows into top air cavity 520A and then through the air cavity connector into bottom air cavity 520B. Air pressure is supplied from air pressure source 519. In one embodiment, the air powering shuttle 522 is heated air, for example, at a temperature of about 180°C to 200°C. However, other temperatures are contemplated. The use of heated air facilitates uniform temperature control of liquid metal pump 500. As air flows into the top and bottom air cavities 520A, 520B, it drives the top diaphragm 506A toward the top surface of the top liquid metal cavity 514A and the bottom diaphragm 506B toward the bottom surface of the bottom liquid metal cavity 514B. The movement of the top diaphragm 506A toward the top surface of the top liquid metal cavity 514A and the movement of the bottom diaphragm 506B toward the bottom surface of the bottom liquid metal cavity 514B forces liquid metal out of the top and bottom liquid metal cavities 514A, 514B through the metal outlet port 512.

[0044] The liquid metal pump 500 allows for independent pressures at the metal inlet port 510 and the metal outlet port 512, allowing the liquid metal pump 500 to be used to move liquid metal from a high-pressure component to a low-pressure component, from a low-pressure component to a high-pressure component, or from an isobaric component. Furthermore, the metal-side platen 502 within the liquid metal pump 500 has a maximum pressure of up to approximately 100 psi. The use of the connector 540 allows the liquid metal pump 500 to effectively meter the volume of liquid metal because the liquid metal pump 500 does not rely on a pressure differential. Each pump cycle pumps a predetermined volume of liquid metal, for example, approximately 0.5 ccm of liquid metal, allowing for a metered flow of liquid metal. Alternatively, it is contemplated that other volumes may be pumped depending on process considerations and membrane size. The volume of liquid metal pumped into the liquid metal cavity (and therefore the pressure exerted by the liquid metal in the liquid metal cavity) as well as the pressure exerted by the air pressure source 519 are controlled using a controller 620 .

[0045] FIG. 6 shows a control schematic 600 for use in the liquid metal pumps 200, 300, 400, and 500 of FIGS. 2-5 in accordance with an embodiment of the present disclosure. A controller 620 is configured to receive data or input as sensor readings 602 from each of the liquid metal pumps 200, 300, 400, and 500. The controller 620 comprises or is in communication with a system model 606 of the liquid metal pumps 200, 300, 400, and 500. The system model 606 includes a metering model. The system model 606 is a program configured to estimate the flow and heating of the liquid metal in the liquid metal pumps 200, 300, 400, and 500 throughout the metering process. The liquid metal pumps 200, 300, 400, and 500 are further configured to store the readings and calculations 604.

[0046] The readings and calculations 604 include the previous sensor readings 602, as well as any other previous sensor readings within the liquid metal pumps 200, 300, 400, and 500. The readings and calculations 604 further include stored calculations from after the sensor readings 602 have been measured by the liquid metal pumps 200, 300, 400, and 500 and run through the system model 606. Thus, the controller 620 is configured to both retrieve the stored readings and calculations 604 and save the readings and calculations 604 for future use. Maintaining the previous readings and calculations allows the controller 620 to adjust the system model 606 over time to reflect more accurate versions of the liquid metal pumps 200, 300, 400, and 500.

[0047] In the embodiments described herein, the controller 620 includes a programmable central processing unit (CPU) operating in conjunction with memory and mass storage devices, an input control unit, and a display unit (not shown). The controller 620 monitors the liquid metal flow, the air flow, the heating, and the operation of the connectors and shuttle. Support circuitry is coupled to the CPU for supporting the processor in a conventional manner. In some embodiments, the controller 620 includes multiple controllers 620 such that the stored readings and calculations 604 and the system model 606 are stored in a controller separate from the controller 620 that operates the liquid metal pumps 200, 300, 400, and 500. In other embodiments, the system model 606 and all of the stored readings and calculations 604 are stored in the controller 620.

[0048] The controller 620 is configured to control aspects of the liquid metal pumps 200, 300, 400, and 500, thereby controlling the heating, the flow of liquid metal and air through the liquid metal pumps 200, 300, 400, and 500, and the operation of the connectors and shuttles. The controller 620 is configured to adjust aspects of the liquid metal pumps 200, 300, 400, and 500 based on sensor readings 602, a system model 606, and stored readings and calculations 604. The controller 620 includes built-in software and compensation algorithms for calibrating metering and heating. The controller 620 may include machine learning algorithms and may use regression or clustering techniques. The algorithms may be unsupervised or supervised.

[0049] In summary, a liquid metal pump is disclosed. The liquid pump includes a metal-side platen including a liquid metal cavity, a first air-side platen including an air cavity, a diaphragm, a liquid metal inlet port, a metal outlet port, a plurality of heating coils, and a shuttle. The diaphragm is disposed between the metal-side platen and the air-side platen at an interface between the metal-side platen and the first air-side platen. The diaphragm separates the liquid metal cavity from the air cavity. The shuttle is attached to the diaphragm and configured to actuate the diaphragm between an open position and a closed position.

[0050] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, the scope of which is determined by the appended claims.

Claims

1. a metal side platen containing a liquid metal cavity; an air side platen including an air cavity; a diaphragm disposed between the metal-side platen and the air-side platen at an interface therebetween such that the diaphragm separates the liquid metal cavity from the air cavity; and a liquid metal inlet port; a metal exit port; a plurality of heating coils; a shuttle attached to the diaphragm and configured to actuate the diaphragm between an open position and a closed position; A liquid metal pump comprising:

2. 2. The liquid metal pump of claim 1, wherein the shuttle comprises a metal-side shuttle and an air-side shuttle.

3. 3. The liquid metal pump of claim 2, further comprising a connector configured to connect the metal-side shuttle and the air-side shuttle to the diaphragm.

4. a metal side shuttle including a metal side top shuttle and a metal side bottom shuttle; the air-side shuttle including an air-side top shuttle and an air-side bottom shuttle; 4. The liquid metal pump of claim 3, further comprising:

5. 2. The liquid metal pump of claim 1, further comprising at least one spring, said at least one spring configured to actuate said shuttle between an open position and a closed position.

6. a first seal between the air-side platen and the metal-side platen, the first seal including a gasket and a knife edge, the gasket including a soft metal material; a second seal between the air-side platen and the metal-side platen, the second seal comprising an o-ring, the o-ring comprising ethylene propylene diene monomer (EPDM), a fluoropolymer elastomer, silicone, fluorosilicone, polyacrylate, or a combination thereof; 10. The liquid metal pump of claim 1, further comprising:

7. 2. The liquid metal pump of claim 1, wherein the liquid metal inlet port and the liquid metal outlet port include check valves.

8. a metal side platen including a first liquid metal cavity and a second liquid metal cavity; a first air side platen including a first air cavity; a second air side platen including a second air cavity; a first diaphragm disposed between the metal side platen and the first air side platen at an interface between the metal side platen and the first air side platen such that the first diaphragm separates the first liquid metal cavity from the first air cavity; a second diaphragm disposed between the metal side platen and the second air side platen at an interface between the metal side platen and the second air side platen such that the second diaphragm separates the second liquid metal cavity from the second air cavity; a liquid metal inlet port; a metal exit port; a plurality of heating coils; a shuttle attached to the diaphragm and configured to actuate the diaphragm between an open position and a closed position; A liquid metal pump comprising:

9. 2. The liquid metal pump of claim 1, wherein the shuttle is disposed within a shuttle cavity, and the liquid metal inlet port and the liquid metal inlet port are in selective fluid communication with the shuttle cavity.

10. 9. The liquid metal pump of claim 8, further comprising an air cavity connector configured to allow air to flow from the first air cavity to the second air cavity.

11. a first air-side platen first seal between the first air-side platen and the metal-side platen, the first air-side platen first seal including a gasket and a knife edge, the gasket including a soft metal material; a second air-side platen first seal between the second air-side platen and the metal-side platen, the second air-side platen first seal including a gasket and a knife edge, the gasket including a soft metal material; a first air-side platen second seal between the first air-side platen and the metal-side platen, the first air-side platen second seal comprising an o-ring, the o-ring comprising ethylene propylene diene monomer (EPDM), a fluoropolymer elastomer, silicone, fluorosilicone, polyacrylate, or a combination thereof; a second air-side platen second seal between the second air-side platen and the metal-side platen, the second air-side platen second seal including an o-ring, the o-ring including ethylene propylene diene monomer (EPDM), a fluoropolymer elastomer, silicone, fluorosilicone, polyacrylate, or a combination thereof; 9. The liquid metal pump of claim 8, further comprising:

12. 9. The liquid metal pump of claim 8, wherein the heating coil maintains the liquid metal at between about 180°C and about 200°C.

13. 9. A liquid metal pump as claimed in claim 8, having a pressure of up to about 100 psi.

14. 9. A liquid metal pump according to claim 8 configured to pump about 0.5 ccm of liquid metal.

15. 1. A controller for a liquid metal pumping system storing instructions that, when executed by a processor, causing the system to actuate a shuttle from a closed position to an open position, flow liquid metal into a first liquid metal cavity through a metal inlet port, actuate the shuttle from the open position to the closed position, and supply air to a first air cavity to flow the liquid metal out of the first liquid metal cavity through a metal outlet port; a controller, wherein a first diaphragm is positioned at an interface between the metal side platen and the first air side platen, between the first air cavity and the first metal cavity, such that the first diaphragm separates the first liquid metal cavity from the first air cavity.

16. 16. The liquid metal pumping system of claim 15, wherein the shuttle is attached to the diaphragm and configured to actuate the diaphragm between the open position and the closed position.

17. a second air side platen; a second diaphragm disposed at an interface between the metal side platen and the second air side platen, between a second air cavity and a second liquid metal cavity, such that the second diaphragm separates the second liquid metal cavity from the second air cavity; and 16. The liquid metal pumping system of claim 15, further comprising:

18. 16. The liquid metal pumping system of claim 15, further comprising a heater coil, said controller using said heater coil to maintain the liquid metal at between about 180°C and about 200°C.

19. 16. The liquid metal pumping system of claim 15, wherein the controller maintains independent pressures at the metal inlet port and the metal outlet port.

20. 16. The liquid metal pumping system of claim 15, wherein the liquid metal pump has a pressure of up to about 100 psi.

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