BACKGROUND

Field

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

Description of the Related Art

[0002] Rechargeable electrochemical storage systems are increasing in importance for many fields of everyday life. High-capacity energy storage devices are used in a growing number of applications, including portable electronics, medical, transportation, grid-connected large energy storage, renewable energy storage, and uninterruptible power supply (UPS). In each of these applications, the charge/discharge time and capacity of energy storage devices are key parameters. In addition, the size, weight, and/or cost of such energy storage devices are also key parameters. Further, low internal resistance is integral for high performance. The lower the resistance, the less restriction the energy storage device encounters in delivering electrical energy. For example, in the case of a battery, internal resistance affects performance by reducing the total amount of useful energy stored by the battery as well as the ability of the battery to deliver high current.

[0003] Alkali metals are thought to have the best chance at achieving the sought after capacity and cycling. However, an effective means of transporting liquid alkali metal through the fabrication machinery for the batteries is still lacking. Conventional apparatuses fail to accurately meter the volumes of alkali liquid metal needed due to dependency on pressure differentials. Further, the use of conventional seals leaves the system open to contamination from air and water, due to the caustic nature of liquid alkali metals and the high temperatures involved with maintaining the alkali metals in liquid form.

[0004] Therefore, there is a need for improved apparatuses for pumping, and specifically, metering liquid alkali metals. SUMMARY

[0005] The present disclosure generally relates to apparatuses for liquid metal pumps. In particular, the apparatuses disclosed herein relate to metering valves 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 metalside platen and the air-side platen at an interface of the metal-side platen and the airside 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 and a closed position.

[0007] In another embodiment, a liquid metal pump is disclosed. The liquid metal pump includes a metal-side platen comprising 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 of 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 of 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 configured to actuate the diaphragm between an open and a closed position.

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

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments of the disclosure and are therefore not to be considered limiting of scope, as the disclosure may admit to other equally effective embodiments.

[0010] Figure 1 is a schematic cross-sectional view of a liquid metal pump, according to the prior art.

[0011] Figure 2 is a schematic cross-sectional view of a liquid metal pump, according to embodiments of the disclosure.

[0012] Figure 3 is a schematic cross-sectional view of a liquid metal pump, according to embodiments of the disclosure.

[0013] Figure 4 is a schematic cross-sectional view of a liquid metal pump, according to embodiments of the disclosure.

[0014] Figure 5 is a schematic cross-sectional view of a liquid metal pump, according to embodiments of the disclosure.

[0015] Figure 6 is a control schematic for use within the liquid metal pumps, according to embodiments of the disclosure.

[0016] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

[0017] Embodiments of the present disclosure generally relate to liquid metal pumps. In particular, the embodiments of the 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 of 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 and a closed position. In another embodiment, a liquid pump is shown and described herein.

[0018] Figure 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 in order 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 in order to heat the liquid metal container 102. The heating element 108 heats the liquid metal container 102 between about 180°C and about 200°C in order to keep the liquid metal 110 in liquid form, although other temperatures which maintain the metal in a liquid state are contemplated. Below temperatures of 180°C, the liquid metal 110 may solidify, thereby preventing the flow of the liquid metal 110.

[0019] To pump the liquid metal 110 from the liquid metal container 102, gas is pumped through the air inlet port 104 to provide a pressure 112 against the liquid metal 110. This creates a high-pressure system within the liquid metal container 102, forcing the liquid metal 110 down into the metal outlet port 106. In one embodiment, the gas pumped into the system is a non-reactive gas. In one embodiment, the non- reactive gas is one of argon, helium, and nitrogen. The high pressure of the gas creates a pressure differential between the liquid metal container 102 and the components of the liquid metal pump 100 that are downstream of the metal outlet port 106.

[0020] The liquid metal pump 100 of the prior art, however, is unable to effectively meter the volume of flow of the liquid metal 110 through the liquid metal pump 100. Because the liquid metal pump 100 is dependent on the use of pressure differentials, a quick change in pressure can result in over-pumping or under-pumping the liquid metal 110. This leads to variations in the volume of liquid metal 110 that flows through the liquid metal pump 100. Therefore, there is a need for improved apparatuses for pumping, and specifically, metering liquid alkali metals.

[0021] Figure 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 the interface of the metal-side platen 202 and the air-side platen 204. The metal-side platen 202 further includes an inlet valve 210, and outlet valve 212, a liquid metal cavity 214, and a first seal cavity 216 for housing a first seal 217 (e.g., o-ring or other gasket) therein. In one embodiment, the inlet valve 210 and the outlet valve 212 are check valves, each check valve including a ball 218. The inlet valve 210 and the outlet valve 212 extend through the metal-side platen 202 and are spaced apart from one another. In one example, the inlet valve 210 and the outlet valve 212 are oriented parallel to one another and/or orthogonal to a plane of the diaphragm 206. The ball 218 prevents flow of liquids through the check valves, depending on their configuration. The check valve of the inlet valve 210 allows liquid to flow into the liquid metal cavity 214 and prevents liquid from flowing out of the liquid metal cavity 214. The check valve of the outlet valve 212 prevents liquid from flowing into the liquid metal cavity 214, but allows liquid to flow out of the liquid metal cavity 214. The inlet valve 210 and outlet valve 212 are at approximately the same pressure, i.e. , +/- 5 Torr. The 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. The first seal cavity 216 receives a first seal 217 to facilitate sealing between the metal-side platen 202 and the air-side platen 204.

[0022] The air-side platen 204 further includes an air cavity 220 adjacent the diaphragm 206, a shuttle 222, a plurality of heating coils 224, and a second seal cavity 226 for housing a second seal 227 (e.g., o-ring or other gasket) therein. The shuttle 222 actuates up and down within a shuttle cavity 228, perpendicular to the plane of the diaphragm 206. The heating coils 224 heat the metal-side platen 202 and air-side platen 204 in order to maintain the liquid metal in liquid form between about 180°C and about 200°C, although other temperatures are contemplated. The heating coils 224 are arranged in a plane parallel to a plane of the diaphragm 206 to facilitate uniform heating. It is contemplated that the heating coils 224 may be a single coil, or alternatively, that the heating coils 224 may be replaced with a heating channel configured to house a heating medium therein. The temperature produced by the heating coils 224 is controlled using the controller 620.

[0023] The diaphragm 206 spans across both the liquid metal cavity 214 and the air cavity 220, separating the liquid metal within 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 the first seal 217 and second seal 227. The first seal 217 is received in the first seal cavity 216 and the metal-side platen 202 is secured on top of 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 the 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 202 on top of and in contact with the air-side platen 204. The pressure exerted by the metal-side platen 202 being secured on top of and in contact with the air-side platen 204 creates a seal for the liquid metal cavity 214 and air cavity 220. In one embodiment, the knife-edge is steel and the gasket is copper.

[0024] The second seal 227 is received in the second seal cavity 226 to provide a secondary seal. After situating the second seal 227 within the second seal cavity 226, the metal-side platen 202 is secured below and in contact with the air-side platen 204. The second seal 227 is compressed within the second seal cavity 226 by securing the metal-side platen 202 below and in contact with the air-side platen 204, thus creating the secondary seal. In one embodiment, the second seal 227 is an o-ring made of a heat-resistant material, such as one of ethylene propylene diene monomer (EPDM), fluoropolymer elastomer (e.g., Viton™, Aflas™, Kalrez™), silicone, fluorosilicone, polyacrylate, or a combination thereof.

[0025] 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 positioned on the liquid metal cavity 214 side of the diaphragm 206. The shuttle 222 and the washer are connected using a screw. This allows the shuttle 222 to drive the diaphragm 206 in either the upward or downward direction, depending on the application. When liquid metal flows into the liquid metal cavity 214 through the inlet valve 210, the diaphragm 206 is forced to move towards a bottom surface of the air-side platen 204, driving the shuttle 222 upward within the shuttle cavity 228. As the shuttle cavity 228 is driven upward in the shuttle cavity 228, the air within the air cavity is allowed to escape. As the liquid metal flows into the liquid metal cavity 214, the outlet valve 212 prevents the flow of the liquid metal out of the liquid metal cavity 214 until a sufficient amount of pressure has been applied to the ball 218.

[0026] Once the liquid metal cavity 214 has filled with liquid metal, air pressure forces the shuttle 222 downward within the shuttle cavity 228. The air pressure is supplied from an air pressure supply source 219. In one embodiment, the air that drives the shuttle 222 is air heated, such as at a temperature of about 180°C to 200°C, although other temperatures are contemplated. Use of heated air facilitates uniform temperature control of the liquid metal pump 200. The shuttle 222 forces the diaphragm 206 downward and allows air to flow into the air cavity 220. The downward motion on the diaphragm 206 puts pressure on the liquid metal within the liquid metal cavity 214, which activates the ball 218 on the outlet valve 212, allowing for the flow of liquid metal out of the liquid metal cavity 214. The ball 218 of the inlet valve 210 prevents the flow of liquid metal through the inlet valve 210. Each pump cycle pumps a predetermined volume, such as about 0.5 ccm of liquid metal, allowing for metered flow of the liquid metal. It is contemplated that other volumes may alternatively be pumped depending on process considerations and diaphragm size. In some examples, the maximum pressure of the liquid metal within the liquid metal cavity 214 is limited to avoid activating the check valves in the inlet valve 210 and outlet valve 212. The volume of liquid metal pumped into the liquid metal cavity 214 (and thus the pressure exerted by the liquid metal onto the diaphragm 206), as well as the pressure exerted by the air pressure supply source 219 on the shuttle 222 (and thus the diaphragm 206) are controlled using a controller 620 as described in Figure 6. In another embodiment, the controller 620 is capable of directly controlling the actuation of the shuttle 222.

[0027] Figure 3 is a schematic cross-sectional view of a liquid metal pump 300. The liquid metal pump 300 is similar to the liquid metal pump 200, but the 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. The liquid metal pump 300 also includes a diaphragm 306 disposed between a metal-side platen 302 and the airside platen 304 at the interface of the metal-side platen 302 and the air-side platen 304. The 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 housing a first seal 317 (e.g., 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 metalside shuttle. A liquid metal flows into the liquid metal cavity 314 through the metal inlet port 310 and flows out of the liquid metal cavity 314 through the metal outlet port 312. The first seal cavity 316 receives a first seal 317, as will be described in further detail herein.

[0028] 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 housing a second seal 327 (e.g., 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 a plurality of heating coils. The heating coils heat the metal-side platen 302 and air-side platen 304 in order to maintain the liquid metal in liquid form between about 180°C and about 200°C, although other temperatures are contemplated. The heating coils are arranged in a plane parallel to a plane of the diaphragm 306 to facilitate uniform heating. It is contemplated that the heating coils may be a single coil, or alternatively, that the heating coils may be replaced with a heating channel configured to house a heating medium therein. The temperature produced by the heating coils is controlled using the controller 620.

[0029] The diaphragm 306 spans across both the liquid metal cavity 314 and the air cavity 320, separating the liquid metal within the liquid metal cavity 314 from the air in the air cavity 320. A connector 340 connects the metal-side top shuttle 350, a metal-side bottom shuttle 352, an air-side top shuttle 360, and an air-side bottom shuttle 362 to the diaphragm 306. The connector 340 moves the diaphragm upward or downward based on the configuration of the metal-side top shuttle 350, a metalside bottom shuttle 352, an air-side top shuttle 360, and an air-side bottom shuttle 362. The connector 340 is actuated by a controller 620, described in Figure 6.

[0030] The liquid metal cavity 314 and the air cavity 320 are vacuum-sealed using the 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 on top of and in contact with the metal-side platen 302 to clamp the diaphragm in place. In one embodiment, first seal 317 is formed using the 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 on top of and in contact with the metal-side platen 302. The pressure exerted by the air-side platen 304 being secured on top of and in contact with the metal-side platen 302 creates a vacuum seal for the liquid metal cavity 314 and air cavity 320. In one embodiment, the knife-edge is steel and the gasket is copper. The second seal 327 is received in the second seal cavity 326 to provide a secondary seal. After situating the second seal 327 within the second seal cavity 326, the air-side platen 304 is secured on top of and in contact with the metal-side platen 302. The second seal 327 is compressed within the second seal cavity 326 by the securing of the air-side platen 304 on top of and in contact with the metal-side platen 302, thus creating the secondary vacuum seal. In one embodiment, the second seal 327 is an o-ring is made of a heat-resistant material, such as one of ethylene propylene diene monomer (EPDM), fluoropolymer elastomer (e.g., Viton™, Aflas™, Kalrez™), silicone, fluorosilicone, polyacrylate, or a combination thereof.

[0031] In one embodiment, the metal-side top shuttle 350 and metal-side bottom shuttle 352 are configured to mate with each other. Likewise, the air-side top shuttle 360 and air-side bottom shuttle 362 are configured to mate with each other. Each of the metal-side shuttles 350, 352 and air-side shuttles 360, 362 are operable between an open position and a closed position. When the metal-side shuttles 350, 352 are in the open position, the air-side shuttle 360, 362 are in the closed position. While in the open position, the metal-side shuttles 350, 352, allow of the flow of liquid metal into the liquid metal cavity 314 from the metal inlet port 310 and prevent the flow of liquid metal out of the liquid metal cavity 314 through the metal outlet port 312. While the air-side shuttle 360, 362 are in the open position, the air-side shuttles allow the flow of air into the air cavity 320 from the air inlet port 366 and prevents the flow of air out of the air cavity 320 through the air outlet port 368. While in the closed position, the metal-side shuttles 350, 352, allow the flow of liquid metal out of the metal outlet port 312 and prevent flow of liquid metal into the liquid metal cavity 314 from the metal inlet port 310. While in the closed position, the air-side shuttles 360, 362 allow the flow of air out of the air cavity 320 through the air outlet port 368 and prevent the flow of air into the air cavity 320 from the air inlet port 366.

[0032] The metal-side spring 354 and the air-side spring 364 actuate the metalside shuttles 350, 352 and air-side shuttles 360, 362 between the open and closed position. The actuation of the metal-side spring 354 and air-side spring 364 are controller 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 flow of liquid metal through the metal outlet port 312. While the liquid metal flows into the liquid metal cavity 314, the diaphragm 306 moves upward toward a bottom surface of the air-side platen 304. Further, the actuation of the metal-side shuttles 350, 352 and air-side shuttles 360, 362 drives the connector 340 upward, causing the connector 340 to drive the diaphragm 306 upward. The movement of the diaphragm 306 upward pushes the air out of the air cavity 320 through air outlet port 368. The air-side shuttles 360, 362 prevent the flow of air into the air cavity 320 from the air inlet port 366.

[0033] Once the liquid metal cavity 314 has filled with liquid metal, the metal-side spring 354 and the air-side spring 364 actuate the metal-side shuttles 350, 352 into the closed position and air-side shuttles 360, 362 into the open position. The actuation of the metal-side spring 354 and air-side spring 364 are controlled by the controller 620. Air pressure forces the diaphragm 306 downward toward the top surface of the metal-side platen 302. The air pressure is supplied from an air pressure supply source 319. In one embodiment, the air that drives the shuttle 322 is air heated, such as at a temperature of about 180°C to 200°C, although other temperatures are contemplated. Use of heated air facilities uniform temperature control of the liquid metal pump 300. The air outlet port 368 is closed by the air-side top shuttle 360. The actuation of the metal-side shuttles 350, 352 and air-side shuttles 360, 362 drives the connector 340 downward, causing the connector 340 to drive the diaphragm 306 downward. The actuation of the connector 340 is controlled by the controller 620. The movement of the diaphragm 306 downward pushes the liquid metal out of the liquid metal cavity 314 through the metal outlet port 312.

[0034] The liquid metal pump 300 allows for independent pressures at the metal inlet port 310 and metal outlet port 312, and can be used to move liquid metal from high pressure components to low pressure components, low pressure components to high pressure components, or from components of equal pressure. Further, the metal-side platen 302 in liquid metal pump 300 has a maximum pressure of up to about 100 psi. The use of the connector 340 allows for the liquid metal pump 300 to effectively meter a volume of liquid metal because the liquid metal pump 300 is not dependent on pressure differentials. Each pump cycle pumps a predetermined volume, such as about 0.5 ccm of liquid metal, allowing for metered flow of the liquid metal. It is contemplated that other volumes may alternatively be pumped depending on process considerations and diaphragm size. The volume of liquid metal pumped into the liquid metal cavity (and thus the pressure exerted by the liquid metal in the liquid metal cavity) as well as the pressure exerted by the air pressure supply source 319 are controlled using the controller 620.

[0035] Figure 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, but the liquid metal pump 400 has an air-side spring 464 instead of shuttles 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 of 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, a plurality of heating coils 424, a liquid metal cavity 414, and a first seal cavity 416 for housing a first seal 417 (e.g., 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 coils 424 heat the metal-side platen 402 and air-side platen 404 in order to maintain the liquid metal in liquid form between about 180°C and about 200°C, although other temperatures are contemplated. The heating coils 424 are arranged in a plane parallel to a plane of the diaphragm 406 to facilitate uniform heating. It is contemplated that the heating coils 424 may be a single coil, or alternatively, that the heating coils 424 may be replaced with a heating channel configured to house a heating medium therein. The temperature produced by the heating coils 424 is controlled using the controller 620.

[0036] 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 housing a second seal 327 (e.g., o-ring or other gasket) therein. The 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 houses a second seal.

[0037] The diaphragm 406 spans across both the liquid metal cavity 414 and the air cavity 420, separating the liquid metal within 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 upward or downward 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.

[0038] The liquid metal cavity 414 and the air cavity 420 are vacuum-sealed using the first seal 417. After situating the first seal 417 within the first and second seal cavities 416, 426, the metal-side platen 402 is secured on top of and in contact with the air-side platen 404. The first seal 417 is compressed within the first and second seal cavities 416, 426 by the securing of the metal-side platen 402 on top of and in contact with the air-side platen 404, thus creating the vacuum seal. In one embodiment, the first seal 417 is an o-ring is made of a heat-resistant material, such as one of ethylene propylene diene monomer (EPDM), fluoropolymer elastomer (e.g., Viton™, Aflas™, Kalrez™), silicone, fluorosilicone, polyacrylate, or a combination thereof. In one embodiment, first seal 417 is formed using the 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 on top of and in contact with the air-side platen 404. The pressure exerted by the metal-side platen 402 being secured on top of and in contact with the air-side platen 404 creates a vacuum seal for the liquid metal cavity 414 and air cavity 420. In one embodiment, the knife-edge is steel and the gasket is copper.

[0039] In one embodiment, the metal-side shuttle 450 and air-side spring 464 are operable between an open position and a closed position. When the metal-side shuttle 450 are in the open position, the air-side spring 464 are in the closed position. While in the open position, the metal-side shuttle 450 allow the flow of liquid metal into the liquid metal cavity 414 from the metal inlet port 410 and prevent the flow of liquid metal out of the liquid metal cavity 414 through the metal outlet port 412. While in the closed position, the metal-side shuttle 450 allow the flow of liquid metal out of the liquid metal cavity 414 through the metal outlet port 412, and prevents flow of liquid metal into the liquid metal cavity 414 through the metal inlet port 410.

[0040] The air-side spring 464 actuates the metal-side shuttle 450 between the open and closed position. The actuation of the air-side spring is controlled by the controller 620. While the metal-side shuttle 450 are 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. Further, the actuation of the air-side spring 464 drives the connector 440 downward, causing the connector 440 to drive the diaphragm 406 downward. The movement of the diaphragm 406 downward pushes the air out of the air cavity 420 through the air outlet port.

[0041] When the metal-side shuttle 450 are 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 metalside platen 402. The air pressure is supplied from an air pressure supply source 419. In one embodiment, the air that drives the shuttle 422 is air heated, such as at a temperature of about 180°C to 200°C, although other temperatures are contemplated. Use of heated air facilitates uniform temperature control of the liquid metal pump 400. Further, the actuation of the air-side spring 464 drives the connector 440 upward, causing the connector 440 to drive the diaphragm 406 downward. The movement of the diaphragm 406 upward pushes the liquid metal out of the liquid metal cavity 414 through the metal outlet port 412.

[0042] The liquid metal pump 400 allows for independent pressures at the metal inlet port 410 and metal outlet port 412, and can be used to move liquid metal from high pressure components to low pressure components, low pressure components to high pressure components, or from components of equal pressure. Further, the metal-side platen 402 in liquid metal pump 400 has a maximum pressure of up to about 100 psi. The use of the connector 440 and air-side spring 464 allows for the liquid metal pump 400 to effectively meter a volume of liquid metal because the liquid metal pump 400 is not dependent on pressure differentials. Each pump cycle pumps a predetermined volume, such as about 0.5 ccm of liquid metal, allowing for metered flow of the liquid metal. It is contemplated that other volumes may alternatively be pumped depending on process considerations and diaphragm size. The volume of liquid metal pumped into the liquid metal cavity (and thus the pressure exerted by the liquid metal in the liquid metal cavity) as well as the pressure exerted by the air pressure supply source 419 are controlled using the controller 620.

[0043] Figure 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 the liquid metal pump 500 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 interface of 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 interface of 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 in a shuttle cavity 528, a top liquid metal cavity 514A, a bottom liquid metal cavity 514B, and a liquid metal cavity connector 515. The 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 liquid metal outlet port 512 are in selectively fluid communication with the shuttle cavity 528. A top metal-side seal cavity 516A and a bottom metalside seal cavity 516B of the metal-side platen house a first seal 517 (e.g., o-ring or other gasket) therein.

[0044] 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 the 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 an open position and a closed position using a check valve. In another embodiment, the air-inlet port 566 and the air outlet port 568 are operable between an open position and a closed position using a spring valve. The spring valve can be manually operated using a set screw, or operated using the controller 620. The heating coils 524A, 524B heat the metal-side platen 502, the top air-side platen 504A, and the bottom air-side platen 504B in order to maintain the liquid metal in liquid form between about 180°C and about 200°C. Below temperatures of 180°C, the liquid metal is likely to solidify. The temperature produced by the heating coils 524A, 524B is controlled using the controller 620.

[0045] The top metal-side seal cavity 516A receives first seal 517A and top airside platen seal cavity 526A receive a first seal 527A. The bottom metal-side seal cavity 516B receives second seal 517B and bottom air-side seal cavity 526B receive a second seal 527B. The first seals 517A, 517B and second seals 527A, 527B create a vacuum seal within the cavities 514A, 514B, 520A, and 520B. In one embodiment, first seal 517A, 517B or second seal 527A, 527B are formed using the 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 top air-side platen 504A on top of and in contact with the metal-side platen 502 and securing the metal-side platen 502 on top of 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 second seal 527A, 527B is an o-ring made of a heat-resistant material, such as one of ethylene propylene diene monomer (EPDM), fluoropolymer elastomer (e.g., Viton™, Aflas™, Kalrez™), silicone, fluorosilicone, polyacrylate, or a combination thereof. The pressure exerted by the top air-side platen 504A being secured on top of and in contact with the metalside platen 502, and the metal-side platen 502 being secured 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.

[0046] The top diaphragm 506A spans across both the top liquid metal cavity 514A and the top air cavity 520A, separating the liquid metal within the top liquid metal cavity 514A from the air in the top air cavity 520A. The bottom diaphragm 506B spans across both the bottom liquid metal cavity 514B and the bottom air cavity 520B, separating the liquid metal within the bottom liquid metal cavity 514B from the air in the bottom air cavity 520B.

[0047] The shuttle 522 actuates between an open position and a closed position. The actuation of the shuttle 522 is controlled by the controller 620. When the shuttle 522 is in the open position, the shuttle 522 allows the flow of the liquid into top liquid metal cavity 514A through the metal inlet port 510 and allows the flow from the bottom liquid metal cavity 514B through the metal outlet port 510. The metal inlet port 512 is closed by the shuttle 522. While the liquid metal flows into the bottom liquid metal cavity 514B, the bottom diaphragm 506B moves downward toward a top surface of the bottom air-side platen 504B. While the liquid metal flows into the top liquid metal cavity 514A, the top diaphragm 506A moves upward toward a bottom surface of the top air-side platen 504A. The movement of the top diaphragm 506A and bottom diaphragm 506B forces the air within the top air cavity 520A and the bottom air cavity 520B to escape through the air outlet port 568.

[0048] When the shuttle 522 is in the closed position, the shuttle 522 allows the flow of liquid metal out of the top liquid metal cavity 514A, through the liquid metal cavity connector 515, and into the bottom liquid metal cavity 514B. Air flows into the top air cavity 520A and subsequently into the bottom air cavity 520B through the air cavity connector. The air pressure is supplied from an air pressure supply source 519. In one embodiment, the air that drives the shuttle 522 is air heated, such as at a temperature of about 180°C to 200°C, although other temperatures are contemplated. Use of heated air facilities uniform temperature control of the liquid metal pump 500. As air flows into the top air cavity 520A and bottom air cavity 520B, the air drives the top diaphragm 506A toward the top surface of the top liquid metal cavity 514A and drives 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 bottom diaphragm 506B toward the bottom surface of the bottom liquid metal cavity 514B forces the liquid metal out of top liquid metal cavity 514A and bottom liquid metal cavity 514B through the metal outlet port 512.

[0049] The liquid metal pump 500 allows for independent pressures at the metal inlet port 510 and metal outlet port 512, and can be used to move liquid metal from high pressure components to low pressure components, low pressure components to high pressure components, or from components of equal pressure. Further, the metal-side platen 502 in liquid metal pump 500 has a maximum pressure of up to about 100 psi. The use of the connector 540 allows for the liquid metal pump 500 to effectively meter a volume of liquid metal because the liquid metal pump 500 is not dependent on pressure differentials. Each pump cycle pumps a predetermined volume, such as about 0.5 ccm of liquid metal, allowing for metered flow of the liquid metal. It is contemplated that other volumes may alternatively be pumped depending on process considerations and diaphragm size. The volume of liquid metal pumped into the liquid metal cavity (and thus the pressure exerted by the liquid metal in the liquid metal cavity), as well as the pressure exerted by the air pressure supply source 519 are controlled using a controller 620.

[0050] Figure 6 illustrates a control schematic 600 for use within the liquid metal pumps 200, 300, 400, and 500 of Figures 2-5, according to embodiments of the present disclosure. The 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 is equipped with or 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 liquid metal flow and heating within the liquid metal pumps 200, 300, 400, and 500 throughout a metering process. The liquid metal pumps 200, 300, 400, and 500 are further configured to store readings and calculations 604.

[0051] The readings and calculations 604 include 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 the stored calculated values from after the sensor readings 602 are measured by the liquid metal pumps 200, 300, 400, and 500 and run through the system model 606. Therefore, the controller 620 is configured to both retrieve stored readings and calculations 604 as well as save readings and calculations 604 for future use. Maintaining previous readings and calculations enables the controller 620 to adjust the system model 606 over time to reflect a more accurate version of the liquid metal pumps 200, 300, 400, and 500.

[0052] In embodiments described herein, the controller 620 includes a programmable central processing unit (CPU) that is operated with a memory and a mass storage device, an input control unit, and a display unit (not shown). The controller 620 monitors the liquid metal flow, air flow, heating, and actuation of the connectors and shuttles. Support circuits are 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 within a separate controller from the controller 620 which operates the liquid metal pumps 200, 300, 400, and 500. In other embodiments, all of the system model 606 and the stored readings and calculations 604 are saved within the controller 620.

[0053] The controller 620 is configured to control the heating, the liquid metal flow, and air flow through the liquid metal pumps 200, 300, 400, and 500, and actuation of the connectors and shuttles by controlling aspects of the liquid metal pumps 200, 300, 400, and 500. The controller 620 is configured to adjust the aspects of the liquid metal pumps 200, 300, 400, and 500 based off the sensor readings 602, the system model 606, and the stored readings and calculations 604. The controller 620 includes embedded software and a compensation algorithm to calibrate metering and heating. The controller 620 may include a machine-learning algorithm and may use a regression or clustering technique. The algorithm may be an unsupervised or a supervised algorithm.

[0054] 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 of 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 and a closed position.

[0055] 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, and the scope thereof is determined by the claims that follow.