Liquid metal metering valve

Abstract

In one embodiment, a liquid metal pump is disclosed. The liquid metal pump comprises a metal side table plate and a liquid metal side table plate, wherein the metal side table plate comprises a liquid metal cavity; the air side table plate comprises an air cavity; a diaphragm; a liquid metal inlet port; a metal outlet port; a plurality of heating coils; and a slider. The diaphragm is arranged between the metal side platen and the air side platen and located at the joint of the metal side platen and the air side platen. The diaphragm separates the liquid metal cavity from the air cavity. A slider is attached to the diaphragm and configured to actuate the diaphragm between an open position and a closed position.

Description

Technical Field

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

[0002] Rechargeable electrochemical storage systems are becoming increasingly important in many areas of daily life. Large-capacity energy storage devices are used in more and more applications, including portable electronics, medical, transportation, grid-connected large 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. In addition, low internal resistance is necessary for high performance. The lower the resistance, the less restrictions the energy storage device encounters when delivering electrical energy. For example, in the case of a battery, the internal resistance affects performance by reducing the total amount of useful energy stored by the battery and the ability of the battery to deliver high currents.

[0003] Alkali metals are considered to have the best potential to achieve the sought-after capacity and cycle. However, an effective means of transporting liquid alkali metals through the manufacturing machinery for batteries is still lacking. Conventional equipment cannot accurately meter the required volume of liquid alkali metal due to its reliance on pressure differentials. In addition, due to the caustic nature of liquid alkali metals and the high temperatures involved in maintaining the alkali metals in liquid form, the use of conventional seals makes the system susceptible to contamination by air and water.

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

[0005] The present disclosure generally relates to devices for liquid metal pumps. In particular, the devices 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, the metal side platen including a liquid metal cavity; an air side platen, the 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 slider. The diaphragm is disposed between the metal side platen and the air side platen at a junction of the metal side platen and the air side platen. The diaphragm separates the liquid metal cavity from the air cavity. The slider is attached to the diaphragm and is 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, the metal side platen including a first liquid metal cavity and a second liquid metal cavity; a first air side platen, the first air side platen including a first air cavity; a second air side platen, the 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 slider. The first diaphragm is disposed between the metal side platen and the first air side platen at the junction 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 the junction 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 slider 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 pump system is disclosed. The controller stores instructions that, when executed by a processor, cause the system to actuate a slider from a closed position to an open position, cause liquid metal to flow into a first liquid metal cavity through a metal inlet port, actuate the slider from an open position to a closed position, and supply air to a first air cavity to cause liquid metal to flow 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 a junction 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] In order that the above-recited features of the present disclosure may be understood in detail, a more particular description of the present disclosure briefly outlined above may be made with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only exemplary embodiments of the present disclosure and are therefore not to be considered limiting of scope, as the present 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 an embodiment of the present disclosure.

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

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

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

[0015] Figure 6 is a control schematic diagram for use in a liquid metal pump according to an embodiment of the present 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, 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, the metal side platen including a liquid metal cavity; a first air side platen, the 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 slider. The diaphragm is disposed between the metal side platen and the air side platen, at the junction of the metal side platen and the first air side platen. The diaphragm separates the liquid metal cavity from the air cavity. The slider is attached to the diaphragm and is configured to actuate the diaphragm between an open position and a closed position. In another embodiment, a liquid pump is shown and described herein.

[0018] Figure 1 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 stores a volume of liquid metal 110. In one embodiment, the liquid metal 110 is a liquid alkali metal. In one embodiment, the liquid alkali metal is one of lithium, sodium, potassium, and cesium. The liquid metal container 102 is vacuum sealed to prevent the liquid metal 110 from being exposed 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 between about 180° C. and about 200° C. to keep the liquid metal 110 in liquid form, but other temperatures that maintain the metal in a liquid state are also contemplated. At a temperature below 180° C., the liquid metal 110 may solidify, thereby preventing the flow of the liquid metal 110 .

[0019] In order to pump the liquid metal 110 from the liquid metal container 102, a gas is pumped through the air inlet port 104 to provide a pressure 112 to the liquid metal 110. This forms a high pressure system within the liquid metal container 102, thereby pushing the liquid metal 110 downward 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 difference between the liquid metal container 102 and the components of the liquid metal pump 100 downstream of the metal outlet port 106.

[0020] However, the prior art liquid metal pump 100 is not able to effectively meter the volume flow of liquid metal 110 through the liquid metal pump 100. Because the liquid metal pump 100 relies on the use of a pressure differential, rapid changes in pressure may result in over-pumping or under-pumping of the liquid metal 110. This causes a change in the volume of liquid metal 110 flowing through the liquid metal pump 100. Therefore, there is a need for an improved apparatus for pumping, and in particular metering, liquid alkali metal.

[0021] Figure 2 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, which is disposed between the metal side platen 202 and the air side platen 204 and at the junction of the metal side platen 202 and the air side platen 204. The metal side platen 202 further includes an inlet valve 210, an outlet valve 212, a liquid metal chamber 214, and a first sealing chamber 216, the first sealing chamber being used to accommodate a first seal 217 (e.g., an o-ring or other gasket) in the first sealing chamber. In one embodiment, the inlet valve 210 and the outlet valve 212 are check valves, each of which includes a ball 218. The inlet valve 210 and the outlet valve 212 extend through the metal side platen 202 and 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 orthogonal to the plane of the diaphragm 206. The ball 218 prevents liquid from flowing through the check valve depending on the configuration of the check valve. 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 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. The first sealing 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 to the diaphragm 206, a slider 222, a plurality of heating coils 224, and a second sealing cavity 226 for receiving a second seal 227 (e.g., an o-ring or other gasket) in the second sealing cavity. The slider 222 actuates up and down within the slider cavity 228 perpendicular to the plane of the diaphragm 206. The heating coils 224 heat the metal side platen 202 and the air side platen 204 to maintain the liquid metal in a liquid form between about 180° C. and about 200° C., although other temperatures are also contemplated. The heating coils 224 are arranged in a plane parallel to the plane of the diaphragm 206 to promote uniform heating. It is contemplated that the heating coils 224 can be a single coil, or alternatively, the heating coils 224 can be replaced with a heating channel configured to receive a heating medium in the heating channel. The temperature generated by the heating coils 224 is controlled using a controller 620.

[0023] The diaphragm 206 spans both the liquid metal cavity 214 and the air cavity 220, thereby 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 sealed cavity 216, and the metal side platen 202 is fixed on top of the air side platen 204 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 soft metal and a knife-edge to form a knife-edge seal. In one embodiment, the knife-edge seal is formed by inserting a knife-edge into a soft metal gasket and then fixing the metal side platen 202 on top of the air side platen 204 and in contact with the air side platen 204. Pressure applied by the metal side platen 202 by securing the metal side platen 202 on top of and in contact with the air side platen 204 forms a seal for the liquid metal cavity 214 and the air cavity 220. In one embodiment, the blade 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 the second seal 227 is placed in the second seal cavity 226, the metal side platen 202 is fixed under the air side platen 204 and in contact with the air side platen 204. By fixing the metal side platen 202 under the air side platen 204 and in contact with the air side platen 204, the second seal 227 is compressed in the second seal cavity 226, thereby forming a secondary seal. In one embodiment, the 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 of the above.

[0025] The slider 222 is connected to the diaphragm 206. In one embodiment, the slider 222 is made of stainless steel. The slider 222 is connected to the diaphragm 206 using a gasket positioned on the liquid metal cavity 214 side of the diaphragm 206. The slider 222 and the gasket are connected using screws. This allows the slider 222 to drive the diaphragm 206 in an 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 toward the bottom surface of the air side platen 204, thereby driving the slider 222 upward within the slider cavity 228. When the slider cavity 228 is driven upward in the slider cavity 228, the air within the air cavity is allowed to escape. When the liquid metal flows into the liquid metal cavity 214, the outlet valve 212 prevents the liquid metal from flowing out of the liquid metal cavity 214 until a sufficient amount of pressure is applied to the ball 218.

[0026] Once the liquid metal cavity 214 has been filled with liquid metal, air pressure pushes the slider 222 downward within the slider cavity 228. The air pressure is supplied by an air pressure supply 219. In one embodiment, the air that drives the slider 222 is heated by air, such as at a temperature of about 180°C to 200°C, but other temperatures are also contemplated. The use of heated air promotes uniform temperature control of the liquid metal pump 200. The slider 222 pushes the diaphragm 206 downward and allows air to flow 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 on the outlet valve 212, thereby allowing 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 (such as about 0.5 ccm) of liquid metal, thereby allowing a metered flow of liquid metal. It is contemplated that other volumes may be pumped alternatively 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 the outlet valve 212. Figure 6 The controller 620 controls the volume of liquid metal pumped into the liquid metal chamber 214 (and thus the pressure applied by the liquid metal to the diaphragm 206) and the pressure applied by the air pressure supply 219 to the slider 222 (and thus the diaphragm 206). In another embodiment, the controller 620 can directly control the actuation of the slider 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 slider. The liquid metal pump 300 also includes a diaphragm 306 disposed between the metal side platen 302 and the air side platen 304, at the junction 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 slider 350, a metal side bottom slider 352, a metal side spring 354, and a first sealing cavity 316, the first sealing cavity being used to accommodate a first seal 317 (e.g., an o-ring or other gasket) in the first sealing cavity. In another embodiment, the metal side top slider 350 and the metal side bottom slider 352 are replaced with a single metal side slider. 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 slider 360, an air side bottom slider 362, an air side spring 364, an air inlet port 366, an air outlet port 368, and a second seal cavity 326 for accommodating a second seal 327 (e.g., an o-ring or other gasket) in the second seal cavity. In another embodiment, the air side top slider 360 and the air side bottom slider 362 are replaced with a single air side slider. In another embodiment, the air side platen includes a plurality of heating coils. The heating coils heat the metal side platen 302 and the air side platen 304 to maintain the liquid metal in a liquid form between about 180° C. and about 200° C., but other temperatures are also contemplated. The heating coils are arranged in a plane parallel to the plane of the diaphragm 306 to promote uniform heating. It is contemplated that the heating coils can be a single coil, or alternatively, the heating coils can be replaced with heating channels that are configured to contain a heating medium in the heating channels. The temperature generated by the heating coil is controlled using controller 620 .

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

[0030] 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 fixed on top of the metal side platen 302 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 soft metal and a blade to form a knife-edge seal. In one embodiment, the knife-edge seal is formed by inserting a knife edge into a soft metal gasket and then fixing the air side platen 304 on top of the metal side platen 302 and in contact with the metal side platen 302. The pressure applied by the air side platen 304 by fixing the air side platen 304 on top of the metal side platen 302 and in contact with the metal side platen 302 forms a vacuum seal for the liquid metal cavity 314 and the air cavity 320. In one embodiment, the blade 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 the second seal 327 is placed in the second seal cavity 326, the air side platen 304 is fixed on top of the metal side platen 302 and in contact with the metal side platen 302. By fixing the air side platen 304 on top of the metal side platen 302 and in contact with the metal side platen 302, the second seal 327 is compressed in the second seal cavity 326, thereby forming a secondary vacuum seal. In one embodiment, the second seal 327 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 of the above items.

[0031] In one embodiment, the metal side top slider 350 and the metal side bottom slider 352 are configured to cooperate with each other. Similarly, the air side top slider 360 and the air side bottom slider 362 are configured to cooperate with each other. Each of the metal side sliders 350, 352 and the air side sliders 360, 362 can be operated between an open position and a closed position. When the metal side sliders 350, 352 are in the open position, the air side sliders 360, 362 are in the closed position. When in the open position, the metal side sliders 350, 352 allow liquid metal to flow into the liquid metal cavity 314 from the metal inlet port 310 and prevent the liquid metal from flowing out of the liquid metal cavity 314 through the metal outlet port 312. When the air side sliders 360, 362 are in the open position, the air side sliders allow air to flow into the air cavity 320 from the air inlet port 366 and prevent air from flowing out of the air cavity 320 through the air outlet port 368. When in the closed position, the metal side sliders 350, 352 allow liquid metal to flow out of the metal outlet port 312 and prevent liquid metal from flowing from the metal inlet port 310 into the liquid metal cavity 314. When in the closed position, the air side sliders 360, 362 allow air to flow out of the air cavity 320 through the air outlet port 368 and prevent air from flowing 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 metal side sliders 350, 352 and the air side sliders 360, 362 between the open position and the closed position. The actuation of the metal side spring 354 and the air side spring 364 is controlled by the controller 620. When the metal side sliders 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 slider 350, thereby preventing the liquid metal from flowing through the metal outlet port 312. When 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. In addition, the actuation of the metal side sliders 350, 352 and the air side sliders 360, 362 drives the connector 340 upward, so that the connector 340 drives the diaphragm 306 upward. The upward movement of the diaphragm 306 pushes air out of the air cavity 320 through the air outlet port 368. The air-side sliders 360 , 362 prevent air from flowing from the air inlet port 366 into the air cavity 320 .

[0033] Once the liquid metal cavity 314 has been filled with liquid metal, the metal side spring 354 and the air side spring 364 actuate the metal side sliders 350, 352 to the closed position and the air side sliders 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. The air pressure pushes the diaphragm 306 downward toward the top surface of the metal side platen 302. The air pressure is supplied by the air pressure supply source 319. In one embodiment, the air driving the slider 322 is heated by air, such as at a temperature of about 180°C to 200°C, but other temperatures are also contemplated. The use of heated air promotes uniform temperature control of the liquid metal pump 300. The air outlet port 368 is closed by the air side top slider 360. The actuation of the metal side sliders 350, 352 and the air side sliders 360, 362 drives the connector 340 downward, thereby causing the connector 340 to drive the diaphragm 306 downward. Actuation of the connector 340 is controlled by the controller 620. The downward movement of the diaphragm 306 pushes the liquid metal out of the liquid metal chamber 314 through the metal outlet port 312.

[0034] The liquid metal pump 300 allows independent pressures at the metal inlet port 310 and the metal outlet port 312, and can 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 a component of equal pressure. In addition, the metal side platen 302 in the liquid metal pump 300 has a maximum pressure of up to about 100 psi. Since the liquid metal pump 300 does not depend on the pressure difference, the use of the connector 340 allows the liquid metal pump 300 to effectively meter the volume of the liquid metal. Each pump cycle pumps a predetermined volume (such as about 0.5 ccm) of liquid metal, thereby allowing a metered flow of liquid metal. It is envisioned that other volumes may be pumped alternatively depending on process considerations and diaphragm size. The volume of liquid metal pumped into the liquid metal cavity (and therefore the pressure applied by the liquid metal in the liquid metal cavity) and the pressure applied by the air pressure supply source 319 are controlled using a controller 620.

[0035] Figure 44 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 a slider 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, which is disposed between the metal side platen 402 and the air side platen 404 and at the junction 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 slider 450 and an optional metal side bottom slider, a plurality of heating coils 424, a liquid metal cavity 414, and a first sealing cavity 416, the first sealing cavity being used to accommodate a first seal 417 (e.g., an o-ring or other gasket) in the first sealing cavity. In another embodiment, the metal side top slide 450 and the metal side bottom slide are replaced with a single metal side slide. The heating coil 424 heats the metal side platen 402 and the air side platen 404 to maintain the liquid metal in a liquid form between about 180° C. and about 200° C., but other temperatures are also contemplated. The heating coil 424 is arranged in a plane parallel to the plane of the diaphragm 406 to promote uniform heating. It is contemplated that the heating coil 424 can be a single coil, or alternatively, the heating coil 424 can be replaced with a heating channel configured to contain a heating medium in the heating channel. The temperature generated by the heating coil 424 is controlled using a 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 receiving a second seal 327 (e.g., an o-ring or other gasket) therein. The first seal 417 is received in the first seal cavity 416 and the second seal cavity 426 to provide a seal. In one embodiment, the second seal cavity 426 receives the second seal.

[0037] The diaphragm 406 spans across both the liquid metal cavity 414 and the air cavity 420, thereby separating the liquid metal in the liquid metal cavity 414 from the air in the air cavity 420. The connector 440 connects the metal-side top slider 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 slider 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 a first seal 417. After the first seal 417 is placed in the first sealed cavity 416 and the second sealed cavity 426, the metal side platen 402 is fixed on the top of the air side platen 404 and in contact with the air side platen 404. By fixing the metal side platen 402 on the top of the air side platen 404 and in contact with the air side platen 404, the first seal 417 is compressed in the first sealed cavity 416 and the second sealed cavity 426, thereby forming 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 a combination of the above items. In one embodiment, the first seal 417 is formed using a gasket made of soft metal and a blade to form a blade seal. In one embodiment, the knife edge seal is formed by inserting a knife edge into a 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 applied by the metal side platen 402 by securing the metal side platen 402 on top of and in contact with the air side platen 404 forms a vacuum seal for the liquid metal cavity 414 and the air cavity 420. In one embodiment, the knife edge is steel and the gasket is copper.

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

[0040] The air side spring 464 actuates the metal side slider 450 between an open position and a closed position. The actuation of the air side spring is controlled by the controller 620. When the metal side slider 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 slider 450. As liquid metal flows into the liquid metal cavity 414, the diaphragm 406 moves downward toward the top surface of the air side platen 404. In addition, the actuation of the air side spring 464 drives the connector 440 downward, causing the connector 440 to drive the diaphragm 406 downward. The downward movement of the diaphragm 406 pushes air out of the air cavity 420 through the air outlet port.

[0041] When the metal side slider 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, thereby moving the diaphragm 406 upward toward the bottom surface of the metal side platen 402. Air pressure is supplied by an air pressure supply source 419. In one embodiment, the air driving the slider 422 is heated by air, such as at a temperature of about 180°C to 200°C, but other temperatures are also contemplated. The use of heated air promotes uniform temperature control of the liquid metal pump 400. In addition, the actuation of the air side spring 464 drives the connector 440 upward, thereby causing the connector 440 to drive the diaphragm 406 downward. The upward movement of the diaphragm 406 pushes the liquid metal out of the liquid metal cavity 414 through the metal outlet port 412.

[0042] Liquid metal pump 400 allows independent pressure at metal inlet port 410 and metal outlet port 412, and can be used to move liquid metal from high pressure component to low pressure component, from low pressure component to high pressure component or from equal pressure component. In addition, the metal side platen 402 in liquid metal pump 400 has a maximum pressure of up to about 100psi. Since liquid metal pump 400 does not depend on pressure difference, the use of connector 440 and air side spring 464 allows liquid metal pump 400 to effectively meter the volume of liquid metal. Each pump cycle pumps a predetermined volume (such as about 0.5ccm) of liquid metal, thereby allowing metered flow of liquid metal. It is envisioned that other volumes may be pumped alternatively depending on process considerations and diaphragm size. Controller 620 is used to control the volume of liquid metal pumped into the liquid metal cavity (and therefore the pressure applied by the liquid metal in the liquid metal cavity) and the pressure applied by air pressure supply source 419.

[0043] Figure 5is 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 also includes a top diaphragm 506A disposed between the metal side platen 502 and the top air side platen 504A, at the junction 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 the junction of the metal side platen 502 and the bottom air side platen 504B. The metal side stage 502 further includes a metal inlet port 510, a metal outlet port 512, a slider 522 disposed in a slider 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 selectively fluidly connected to the slider cavity 528. The top metal side sealing cavity 516A and the bottom metal side sealing cavity 516B of the metal side stage accommodate a first seal 517 (e.g., an o-ring or other gasket) in the top metal side sealing cavity 516A and the bottom metal side sealing cavity 516B.

[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 sealed 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 sealed 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 can be operated 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 can be operated between an open position and a closed position using a spring valve. The spring valve can be manually operated using a set screw, or can be operated using a 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 to maintain the liquid metal in a liquid form at a temperature between about 180° C. and about 200° C. Below a temperature of 180° C., the liquid metal is likely to solidify. The temperature generated by the heating coils 524A, 524B is controlled using a controller 620.

[0045] The top metal side seal cavity 516A receives a first seal 517A, and the top air side platen seal cavity 526A receives a first seal 527A. The bottom metal side seal cavity 516B receives a second seal 517B, and the bottom air side seal cavity 526B receives a second seal 527B. The first seals 517A, 517B and the second seals 527A, 527B form a vacuum seal within the cavities 514A, 514B, 520A, and 520B. In one embodiment, the first seals 517A, 517B or the second seals 527A, 527B are formed using a gasket made of soft metal and a knife edge to form a knife edge seal. In one embodiment, the knife edge seal is formed by inserting a knife edge into a soft metal gasket and then securing the top air side stage 504A on top of and in contact with the metal side stage 502 and securing the metal side stage 502 on top of and in contact with the bottom air side stage 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 one of ethylene propylene diene monomer (EPDM), fluoropolymer elastomer (e.g., Viton™, Aflas™, Kalrez™), silicone, fluorosilicone, polyacrylate, or a combination of the above. The pressure applied by the top air side platen 504A and the metal side platen 502 by fixing the top air side platen 504A on the top of the metal side platen 502 and in contact with the metal side platen 502 and fixing the metal side platen 502 on the top of the bottom air side platen 504B and in contact with the bottom air side platen 504B forms a vacuum seal for the top liquid metal cavity 514A and the bottom liquid metal cavity 514B and the top air cavity 520A and the bottom air cavity 520B.

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

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

[0048] When the slider 522 is in the closed position, the slider 522 allows liquid metal to flow out of the top liquid metal cavity 514A, flow through the liquid metal cavity connector 515 and flow into the bottom liquid metal cavity 514B. Air flows into the top air cavity 520A and then flows into the bottom air cavity 520B through the air cavity connector. The air pressure is supplied by the air pressure supply source 519. In one embodiment, the air driving the slider 522 is heated by air, such as at a temperature of about 180°C to 200°C, but other temperatures are also contemplated. Uniform temperature control of the liquid metal pump 500 using the heated air facility. When air flows into the top air cavity 520A and the 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. Movement of the top diaphragm 506A toward the top surface of the top liquid metal cavity 514A and movement of the bottom diaphragm 506B toward the bottom surface of the bottom liquid metal cavity 514B pushes liquid metal out of the top liquid metal cavity 514A and the bottom liquid metal cavity 514B through the metal outlet port 512 .

[0049] The liquid metal pump 500 allows independent pressures at the metal inlet port 510 and the metal outlet port 512, and can 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 a component of equal pressure. In addition, the metal side platen 502 in the liquid metal pump 500 has a maximum pressure of up to about 100 psi. Since the liquid metal pump 500 does not depend on the pressure difference, the use of the connector 540 allows the liquid metal pump 500 to effectively meter the volume of the liquid metal. Each pump cycle pumps a predetermined volume (such as about 0.5 ccm) of liquid metal, thereby allowing a metered flow of liquid metal. It is envisioned that other volumes may be pumped alternatively depending on process considerations and diaphragm size. A controller 620 is used to control the volume of liquid metal pumped into the liquid metal cavity (and therefore the pressure applied by the liquid metal in the liquid metal cavity) and the pressure applied by the air pressure supply source 519.

[0050] Figure 6 The invention illustrates a method for Figures 2 to 5 A control schematic 600 within a liquid metal pump 200, 300, 400, and 500 of FIG. 600. 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 is equipped with or communicates with a system model 606 of the liquid metal pumps 200, 300, 400, and 500. The system model 606 includes a metrology 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 the metrology process. The liquid metal pumps 200, 300, 400, and 500 are further configured to store readings and calculate 604.

[0051] The readings and calculations 604 include the previous sensor readings 602 and any other previous sensor readings within the liquid metal pumps 200, 300, 400, and 500. The readings and calculations 604 further include calculated values ​​stored 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 the stored readings and calculations 604 and save the readings and calculations 604 for future use. Maintaining the 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 the embodiments described herein, the controller 620 includes a programmable central processing unit (CPU) operating 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 connector and the slider. 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 so 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, all system models 606 and stored readings and calculations 604 are stored in the controller 620.

[0053] The controller 620 is configured to control heating, liquid metal flow and air flow through the liquid metal pumps 200, 300, 400, 500 and actuation of the connector and the slider by controlling various aspects of the liquid metal pumps 200, 300, 400, 500. The controller 620 is configured to adjust various aspects of the liquid metal pumps 200, 300, 400, and 500 based on sensor readings 602, system models 606, and stored readings and calculations 604. The controller 620 includes embedded software and compensation algorithms for calibrating metering and heating. The controller 620 may include a machine learning algorithm and may use regression or clustering techniques. The algorithm may be an unsupervised algorithm or a supervised algorithm.

[0054] In summary, a liquid metal pump is disclosed. The liquid pump includes: a metal side platen, the metal side platen including a liquid metal cavity; a first air side platen, the 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 slider. The diaphragm is disposed between the metal side platen and the air side platen at a junction of the metal side platen and the first air side platen. The diaphragm separates the liquid metal cavity from the air cavity. The slider is attached to the diaphragm and is configured to actuate the diaphragm between an open position 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 of the disclosure, and the scope of the disclosure is determined by the appended claims.

Claims

1. A liquid metal pump, comprising: a metal side stage, the metal side stage comprising a liquid metal cavity; an air side deck, the air side deck comprising an air cavity; a diaphragm disposed between the metal side platen and the air side platen and at a junction of the metal side platen and the air side platen, so that the diaphragm separates the liquid metal cavity from the air cavity; Liquid metal inlet port; Metal outlet port; multiple heating coils; as well as A slider is attached to the diaphragm and is configured to actuate the diaphragm between an open position and a closed position. 2 . The liquid metal pump according to claim 1 , wherein the slider comprises a metal-side slider and an air-side slider. 3 . The liquid metal pump of claim 2 , further comprising a connector configured to connect the metal-side slider and the air-side slider to the diaphragm.

4. The liquid metal pump according to claim 3, further comprising: The metal side slider comprises a metal side top slider and a metal side bottom slider; and The air side slider includes an air side top slider and an air side bottom slider. 5 . The liquid metal pump of claim 1 , further comprising at least one spring configured to actuate the slide between an open position and a closed position.

6. The liquid metal pump according to claim 1, further comprising: a first seal between the air side platen and the metal side platen, the first seal comprising a gasket and a blade, the gasket comprising a soft metal material; as well as A second seal between the air side platen and the metal side platen, the second seal comprising an o-ring comprising EPDM, fluoropolymer elastomer, silicone, fluorosilicone, polyacrylate or a combination thereof.

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

8. A liquid metal pump, comprising: A metal side stage, the metal side stage comprising a first liquid metal cavity and a second liquid metal cavity; a first air side deck, the first air side deck comprising a first air cavity; a second air side deck, the second air side deck comprising a second air cavity; a first diaphragm, the first diaphragm being disposed between the metal side platen and the first air side platen and at a junction of 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, the second diaphragm being disposed between the metal side platen and the second air side platen and at a junction of the metal side platen and the second air side platen, so that the second diaphragm separates the second liquid metal cavity from the second air cavity; Liquid metal inlet port; Metal outlet port; multiple heating coils; as well as A slider is attached to the diaphragm and is configured to actuate the diaphragm between an open position and a closed position.

9. The liquid metal pump of claim 1, wherein the slider is disposed in a slider cavity, and wherein the liquid metal inlet port and the liquid metal inlet port are in selective fluid communication with the slider cavity. 10 . The liquid metal pump of claim 8 , further comprising an air cavity connector configured to enable air to flow from the first air cavity to the second air cavity.

11. The liquid metal pump according to claim 8, further comprising: 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 comprising a gasket and a blade, the gasket comprising 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 comprising a gasket and a blade, the gasket comprising 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 comprising ethylene propylene diene monomer (EPDM), fluoropolymer elastomer, silicone, fluorosilicone, polyacrylate, or a combination thereof; and 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 comprising an o-ring comprising ethylene propylene diene monomer rubber (EPDM), fluoropolymer elastomer, silicone, fluorosilicone, polyacrylate or a combination thereof.

12. 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. The liquid metal pump of claim 8, wherein the liquid metal pump has a pressure of up to about 100 psi.

14. The liquid metal pump of claim 8, wherein the liquid metal pump is configured to pump approximately 0.5 ccm of liquid metal.

15. A controller for a liquid metal pump system, the controller storing instructions which, when executed by a processor, cause the system to: Actuating the slider from the closed position to the open position to allow liquid metal to flow into the first liquid metal cavity through the metal inlet port, actuating the slider from the open position to the closed position, and supplying air to the first air cavity to allow the liquid metal to flow out of the first liquid metal cavity through the metal outlet port, wherein: The first diaphragm is disposed between the first air cavity and the first metal cavity and at the junction of the metal side stage and the first air side stage, so that the first diaphragm separates the first liquid metal cavity from the first air cavity.

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

17. The liquid metal pump system of claim 15, further comprising: a second air side deck; as well as A second diaphragm, wherein the second diaphragm is arranged between the second air cavity and the second liquid metal cavity and at the junction of the metal side platen and the second air side platen, so that the second diaphragm separates the second liquid metal cavity from the second air cavity.

18. The liquid metal pump system of claim 15, further comprising a heater coil, wherein the controller uses the heater coil to maintain the liquid metal between about 180°C and about 200°C.

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

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

Images