High temperature melt pumps and high temperature melt pump systems

Abstract

The objective of the present invention is to provide a technology for achieving a high-temperature melt pump that can be used in devices requiring a high-temperature melt to be circulated, and that is more economical and practical.　This high-temperature melt pump is a pump for transporting a fuel salt (10) within a pipe (15) in a predetermined direction, and comprises: the pipe (15); a plurality of fluid diodes (16) provided midway along the pipe (15); a pump main body container (7) which is connected to the pipe (15) and which is filled with a cover gas (17) that comes into contact with the fuel salt (10); and a gas vibration generating device (12) for transmitting vibrations to the fuel salt (10) in the pump main body container (7) by way of the cover gas (17).

Description

[Technical field]

[0001] The present invention relates to a high temperature melt pump and a high temperature melt pump system. [Background technology]

[0002] The following Patent Document 1 discloses a technique for a sodium pump used in a fast reactor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-219476 Summary of the Invention [Problem to be solved by the invention]

[0004] In devices that use molten salt or molten metal (hereinafter, molten salt and high-temperature liquids other than molten metal are also referred to as "high-temperature melt") as a coolant to transport heat or cool reactors, such as nuclear fusion reactors, molten salt reactors, and molten metal-cooled fast reactors, a pump for circulating the high-temperature melt (hereinafter, referred to as a "high-temperature melt pump") is required. A high-temperature melt pump must be able to transport extremely hot high-temperature melt at a certain flow rate or above, while also being equipped with a seal structure to prevent leakage of the high-temperature melt from the high-temperature melt pump and the cover gas inside the high-temperature melt pump, and must also be able to accommodate regular maintenance, so it is quite difficult to develop a high-temperature melt pump that can achieve the required performance.

[0005] The most common type of high-temperature melt pump is a turbo-type pump, such as a centrifugal pump or mixed-flow pump, which uses an impeller to transport the high-temperature melt, as used in the Molten Salt Experimental Reactor (MSRE) at Oak Ridge National Laboratory and as a sodium pump in the fast reactors Joyo and Monju. Although bearings are essential for the shaft that rotates the impeller, considerable ingenuity is required to design a bearing system that functions stably in high-temperature environments and to design seals to prevent leakage of the high-temperature melt and the cover gas inside the high-temperature melt pump. Furthermore, since the motor that rotates the shaft will not function under high temperatures, the shaft must be significantly longer or a special cooling system must be considered.

[0006] Regarding the bearing problem, the MSRE uses ball bearings and oil lubricant that also acts as a coolant. However, there have been problems with this oil getting mixed into the fuel salt. While oil mixing may be acceptable in an experimental reactor that will only operate for about four years, it is difficult to tolerate in a commercial reactor that will operate for several decades or more.

[0007] On the other hand, the lower bearings in Joyo and Monju that are immersed in liquid sodium use fluid bearings that use the liquid sodium as a lubricant. In fast reactors, liquid sodium is used only as a coolant, so there is little chance of impurities being mixed in, and this does not pose any particular problems, but in molten salt reactors, rare earths and rare metals, which are fission products, are present in the molten salt. These fission products can precipitate and damage the bearings, making it inappropriate to use fluid bearings.

[0008] When fluid bearings cannot be used, ceramic bearings or magnetic bearings are an option, but ceramic bearings have issues with wear on the sliding parts, making long-term stable operation problematic. On the other hand, magnetic bearings solve the friction problem, but because they use magnetic force for bearing, they cannot be used in high temperature environments of 200°C or higher. To use magnetic bearings, they need to be cooled to below 200°C.

[0009] Because the motor that drives the impeller is also magnetically driven, there are almost no products that can be used in high temperature environments of over 200°C. Therefore, it is essential to have a design that cools the motor section to below 200°C.

[0010] A high-temperature melt pump that can solve the above problems and satisfy the required conditions would have to have an extremely complicated structure. To cool the driving devices such as the bearings and motor, the shaft connecting the impeller, which comes into direct contact with the high-temperature melt, to the driving device would need to be quite long; Monju requires a shaft length of about 7m, and Joyo requires a shaft length of about 5m.

[0011] Such a high-temperature melt pump having a complicated structure is difficult to maintain and poses various problems in terms of economy and practicality.

[0012] To solve these problems, a fundamental shift in thinking is required: how can we create a high-temperature melt pump that does not require any moving parts inside the pump, has a simple structure, and can be operated with almost no maintenance?

[0013] The present invention has been made in consideration of the above circumstances, and aims to provide technology related to the realization of a high-temperature melt pump that is more economical and practical and can be used in equipment that requires the circulation of high-temperature melt. [Means for solving the problem]

[0014] To achieve the above object, the high-temperature melt pump of the present invention employs a reciprocating positive displacement pump similar to a piston pump or a diaphragm pump. In these reciprocating positive displacement pumps, a piston or a diaphragm performs a reciprocating motion to transport the liquid. In a reciprocating positive displacement pump, the pump alternately sucks in and expels the liquid, and thus is provided with a fluid diode as a mechanism for transporting the liquid in a predetermined direction, just like a general reciprocating positive displacement pump. However, in a typical reciprocating positive displacement pump, the piston or diaphragm is in direct contact with the liquid, but in the case of a diaphragm, there is no material that can be used with high-temperature liquids such as high-temperature melts, and in the case of a piston, the sliding part functions like a fluid bearing, so in a molten salt reactor, the same problems as with turbo pumps occur. Also, because the piston drive device (motor, etc.) is connected to the piston, the same problems of motor drive at high temperatures as with the turbo pump mentioned above occur. Therefore, in the present invention, instead of directly transporting the high-temperature melt by the reciprocating motion of the piston, the piston generates a reciprocating motion of the cover gas, and the kinetic energy is transmitted to the high-temperature melt, generating a motion that alternately sucks in and expels the high-temperature melt, thereby achieving the same function as a general reciprocating positive displacement pump. Because the piston is a device that generates a reciprocating motion of the cover gas, it does not necessarily need to be placed near the high-temperature melt, it can be easily cooled, and various methods can be selected for the bearing mechanism of the piston sliding part. Therefore, the high temperature melt pump according to one aspect of the present invention has: A high-temperature melt pump that transports high-temperature melt in a pipe in a predetermined direction, The piping; A plurality of fluid diodes provided in the middle of the piping; a pump body container to which the piping is connected and in which a cover gas is sealed and which is in contact with the high-temperature melt; a gas vibration generating device that transmits vibrations to the high-temperature melt in the pump body container via the cover gas; The present invention is characterized in that it comprises: Effect of the Invention

[0015] According to the present invention, it is possible to provide a technology for realizing a high-temperature melt pump that is more economical and practical and can be used in devices that require the circulation of high-temperature melt. [Brief description of the drawings]

[0016] [Figure 1] 1 is a configuration diagram showing an example of a high-temperature melt pump and a high-temperature melt pump system according to the present invention. [Diagram 2] FIG. 2 is an enlarged view of the high-temperature melt pump of FIG. [Diagram 3] FIG. 3 is an enlarged cross-sectional view of a Tesla valve, which is an example of the fluid diode of FIG. 2. [Figure 4] 2 is a diagram showing an example of a transition of vibration pressure in a gas vibration generator in which a piston is driven by a triple eccentric mechanism in FIG. 1. FIG. [Diagram 5] 2 is a diagram showing an example of a change in pump transport rate in the pump body of FIG. 1. [Figure 6] FIG. 2 is a diagram showing an example of a transition of vibration pressure in a piston-driven gas vibration generator using a double cam mechanism instead of the triple eccentric mechanism of FIG. 1. [Figure 7] FIG. 7 is a diagram showing an example of a change in pump transport rate in a pump main body when the gas vibration generator assumed in FIG. 6 is used. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. It should be noted that what is described below is merely an example, and the technical scope of the present invention is not limited to this example. FIG. 1 is a configuration diagram showing an example of a high-temperature melt pump and a high-temperature melt pump system according to the present embodiment. In this embodiment, a molten salt reactor plant will be described as an example. However, the present invention is not limited to a molten salt reactor plant. The present invention can also be applied to a nuclear fusion reactor or a fast reactor. In addition, the present invention can also be applied to a solar thermal power generation system that uses molten salt when storing solar heat, a material manufacturing plant that uses high-temperature melt, and the like.

[0018] <About Molten Salt Reactor Plants> The molten salt reactor plant shown in Figure 1 is composed of a containment vessel 1, a molten salt reactor 2 (reactor) enclosed by the containment vessel 1, a drain tank (not shown) also enclosed by the containment vessel 1, a high-temperature melt pump system 3, a heat exchanger 4, and piping 6 connecting the core 5 of the molten salt reactor 2 and the heat exchanger 4.

[0019] In a molten salt reactor plant, when fuel salt 10, which will be described later, flows into the core 5 of the molten salt reactor 2, a nuclear fission reaction occurs, and the thermal energy generated by the nuclear fission reaction is extracted via the heat exchanger 4. The extracted thermal energy is then converted into rotational energy, which is then converted into electrical energy by a generator to generate electricity.

[0020] The heat exchanger 4 is provided to transfer the thermal energy generated by the nuclear fission reaction to the cooling salt of the secondary loop. The high-temperature melt pump system 3 is provided to forcibly circulate the fuel salt 10 described below. The heat exchanger 4 is connected to the piping of the secondary loop through which the cooling salt flows.

[0021] <About High Temperature Melt Pump System 3> The high temperature melt pumping system 3 will now be described with reference to FIGS. As described above, FIG. 1 is a configuration diagram showing an example of the high-temperature melt pump, high-temperature melt pump system, and nuclear reactor plant of the present invention, and FIG. 2 is an enlarged view of the high-temperature melt pump of FIG.

[0022] Such a high-temperature melt pump system 3 includes a plurality of high-temperature melt pumps (FIG. 1 shows an example of three pumps, and FIG. 2 shows a single high-temperature melt pump), a drive control device 8, and a pulsation adjustment device 9. The high temperature melt pumping system 3 functions between the molten salt reactor 2 and the heat exchanger 4 and transports fuel salt 10 in a direction from the molten salt reactor 2 towards the heat exchanger 4 .

[0023] <About high temperature melt pumps> The high-temperature melt pump is mainly composed of a pump body 11 and a gas vibration generator 12. The high-temperature melt pump also includes a pulsation control device 9 as necessary. In the high-temperature melt pump, the pump body 11 is disposed inside the containment vessel 1, and the gas vibration generator 12 is disposed outside the containment vessel 1. In an example of use as a thorium molten salt reactor, the temperature of the cover gas 13 filled inside the containment vessel 1 is maintained at approximately 500°C, and the temperature of the external environment 14 outside the containment vessel 1 is assumed to be, for example, below 100°C.

[0024] [About pump body 11] The pump body 11 includes a pipe 15, a fluid diode 16, and a pump body container 7 in which a fuel salt 10 is held and a cover gas 17 is sealed. The pump body 11 is connected to a gas vibration generator 12 via a pipe 19. In addition, in FIG. 1, the pump body 11 is shown as being located between the molten salt reactor 2 and the containment vessel 1, but the location of the pump body 11 is not particularly limited to that shown in FIG.

[0025] [About piping 15] The piping 15 includes a first piping 151 on the upstream side and a second piping 152 on the downstream side. One end of the first piping 151, an upstream end 151a, is connected to the upper part of the molten salt reactor 2. The other end 151b of the first piping 151 is disposed inside the pump main body vessel 7. 1 and 2, the first pipe 151 extends straight upward from the upstream end 151a, makes a U-turn at the upper position of the pump main body container 7, and enters the inside of the pump main body container 7. The other end 151b of the first pipe 151 is disposed at the lower inside of the pump main body container 7. A fluid diode 16 is provided midway along the first pipe 151 on the side of the other end 151b.

[0026] One end 152a of the second pipe 152 is disposed at the bottom inside the pump main body container 7. One end 152a is disposed at a position lower than the other end 151b of the first pipe 151. The second pipe 152 extends straight upward from one end 152a, makes a U-turn at the upper position of the pump main body container 7, and is drawn out to the outside of the pump main body container 7. A fluid diode 16 is provided midway along the second pipe 152 drawn out to the outside of the pump main body container 7. The other end of the second pipe 152, that is, a downstream pipe end 152b, is connected to the heat exchanger 4 via a pulsation adjusting device 9.

[0027] [About Fluid Diode 16] The fluid diode 16 will now be described with reference to FIG. Fig. 3 is an example of an enlarged cross-sectional view of the fluid diode of Fig. 1 and Fig. 2. Fig. 1 and Fig. 2 will also be referred to as necessary.

[0028] The fluid diode 16 allows the fuel salt 10 to flow in a predetermined direction. That is, the fluid diode 16 has a function of allowing liquid to flow in a predetermined direction, but not at all or allowing only a small amount of liquid to flow in the reverse direction. A "Tesla valve" or "check valve" having a simple structure is used as the fluid diode 16 here. 3 shows an example of a case where the fluid diode 16 is a "Tesla valve", which is made of the same metal as the pipe 15, and has a flow path 162 formed in a fluid diode body 161. The flow path 162 is formed in a shape in which multiple teardrop-shaped loops 163 are connected. The flow path 162 of this shape allows the fuel salt 10 to flow smoothly in the forward direction, but has the function of impeding the flow in the reverse direction. The fluid diodes 16 inside the pump body vessel 7 are arranged to direct the flow of fuel salt 10 into the pump body vessel 7 , and the fluid diodes 16 outside the pump body vessel 7 are arranged to direct the flow of fuel salt 10 towards the heat exchanger 4 .

[0029] [About the pump body container 7] As described above, the pump main container 7 is a metal container in which the fuel salt 10 is held and the cover gas 17 is sealed. In the pump main container 7, vibrations generated in the cover gas 17 in contact with the fuel salt 10 are transmitted to the fuel salt 10. The vibrations are generated by a gas vibration generator 12, which will be described below.

[0030] [Regarding gas vibration generator 12] The gas vibration generator 12 is a device for generating vibrations in the cover gas 17, and includes a piston portion 20 having a piston, and a motor 21 for moving the piston up and down. The gas vibration generator 12 is controlled by a drive control device 8.

[0031] The piston unit 20 includes a piston, a cylinder, a drive shaft, and a connecting rod. The piston unit 20 is surrounded by a metal container 22 in which the cover gas 17 is sealed. The aforementioned drive unit (not shown) is a device that rotates the drive shaft of the piston portion 20, and is configured to include a motor, wiring, a power source, and the like.

[0032] The gas vibration generator 12 is not particularly limited as long as it can generate gas vibration and may be of a type other than the piston type described above.

[0033] [About the pulsation adjustment device 9] The pulsation adjustment device 9 is a tank (adjusting tank) into which the fuel salt 10 flows before it flows into the heat exchanger 4, and which absorbs pulsation generated in the fuel salt 10. The pulsation adjustment device 9 is a device that absorbs excessive pulsation by an air chamber 18 or the like.

[0034] <About the drive control device 8> The drive control device 8 is a device that manages and adjusts the state of vibration generation by each of the gas vibration generators 12 of the multiple high-temperature melt pumps. The drive control device 8 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The control unit 12 is configured to include a gas vibration generator 12a, a gas vibration control unit 12b, and a communication unit 12c, and an inverter or the like as necessary. The control unit 12c controls the drive of each gas vibration generator 12 and controls the frequency of gas vibration, thereby controlling the pump transport speed.

[0035] <About the operation of the high-temperature melt pump system 3> The vibrations generated in the cover gas 17 are transmitted to the fuel salt 10 with which the cover gas 17 is in contact, and the fuel salt 10 flows from the upper part of the molten salt reactor 2 through the first pipe 151 and the fluid diode 16 into the pump main body container 7, and then flows through the second pipe 152 and the fluid diode 16 into the pulsation control device 9. Then, after flowing into the heat exchanger 4, the fuel salt 10 returns to the core 5 from the lower part of the molten salt reactor 2 via the pipe 6.

[0036] <How to eliminate pulsation in high-temperature melt pump system 3> A method for eliminating pulsation by phase adjustment will be described with reference to Figures 4 to 7. Figures 1 to 3 will also be referenced as necessary. FIG. 4 is a diagram showing an example of a transition of vibration pressure in the gas vibration generator in which a piston is driven by the triple eccentric mechanism of FIG. Fig. 5 is a diagram showing an example of the transition of the pump transport volume in the pump body of Fig. 1, with the total transport volume obtained by superimposing the transport volumes of the three pumps being shown by a solid line. In the gas vibration generator 12, the pistons are driven by an eccentric mechanism, and the three pistons move in conjunction with each other with a shift of one-third of a rotation, so that the vibration pressures each transition along a sine curve. As shown in Figure 2, each pump uses a Tesla valve (fluid diode 16), so when the vibration pressure from the gas vibration generator 12 is positive, a large amount of fuel salt 10 is transported, and when it is negative, a small amount of fuel salt 10 flows back. The pump transport volumes from the three pump bodies 11 are superimposed as a whole in a waveform as shown in Figure 5, and the pulsation of the pump transport volume of fuel salt 10 flowing into the pulsation adjustment device 9 is significantly reduced. Theoretical calculations show that the ratio of pulsation to the average pump transport volume is about ±7%. Although this triple high-temperature melt pump system cannot completely eliminate pulsation, the pulsation regulator 9 can absorb a considerable amount of pulsation.

[0037] FIG. 6 is a diagram showing an example of a transition of vibration pressure in a piston-driven gas vibration generator using a double cam mechanism instead of the triple eccentric mechanism of FIG. FIG. 7 is a diagram showing an example of a transition in pump transport rate in the pump body when the gas vibration generator assumed in FIG. 6 is used. When it is necessary to eliminate pulsation almost completely, a method can be considered in which a piston-driven gas vibration generator with a double cam mechanism is used instead of the triple eccentric mechanism in Fig. 1 to generate oscillating pressure fluctuations as shown in Fig. 6. By incorporating piston movement into the cam such that a positive pressure equivalent to the backflow volume generated by using a Tesla valve (fluid diode 16) is added, pulsation can be almost eliminated in the overall pump transport volume of high-temperature melt transported from the two pump bodies, as shown in Fig. 7. In this case, there is no need to install an air chamber 18 in the pulsation adjustment device 9. The method for eliminating the pulsation is not limited to the above method, and other methods for eliminating the pulsation can also be used.

[0038] <Effects> As has been explained above with reference to Figures 1 to 7, the pump body 11 in which the fuel salt 10 is held can provide a pump of extremely simple structure, and in particular, when a Tesla valve is used for the fluid diode 16, the pump body 11 can have an extremely simple structure with no moving parts. Since the structure of the pump body 11 is extremely simple, for example, it is easy to identify the cause of a failure, and it can be designed to be basically maintenance-free. In addition, since the maintenance target is only the gas vibration generator 12 outside the containment vessel 1, the maintenance load can be significantly reduced.

[0039] As can be seen from the above configuration and structure, the high-temperature melt pump can have a much simpler pump structure than known turbo pumps. In particular, the pump body 11 is composed of only the piping 15, the fluid diode 16, and the pump body container 7, so the number of parts can be significantly reduced. In the high-temperature melt pump, since the gas vibration generator 12 is disposed outside the containment vessel 1, the cooling structure (not shown) can be simplified, and as a result, the number of parts can be reduced. For these reasons, a considerable cost reduction can be expected with high-temperature melt pumps compared to turbo pumps.

[0040] In the high-temperature melt pump, the gas vibration generator 12 can be located at any position away from the pump body 11 arranged inside the containment vessel 1. Therefore, compared to known turbo-type pumps, it is easier to cool the drive unit (not shown) of the gas vibration generator 12, and as a result, it can handle even high-temperature melt with a considerably high temperature. Furthermore, since the high-temperature melt pump does not use fluid bearings or the like, when a Tesla valve is used for the fluid diode 16, it can also be used for high-temperature melt containing fine solid particles, so long as the size of the fluid diode 16 is considerably smaller than that of the flow path 162.

[0041] <Summary> As has been explained above with reference to Figures 1 to 7, the effect is that it is possible to provide a technology for realizing a high-temperature melt pump that is more economical and practical and can be used in equipment that requires the circulation of high-temperature melt.

[0042] Although one embodiment and other embodiments have been described, the present invention is not limited thereto. Furthermore, the effects described in the embodiments are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments.

[0043] The high-temperature melt pump to which the present invention is applied is sufficient if it has the following configuration, and can take various forms. That is, (1) the high-temperature melt pump to which the present invention is applied (for example, the high-temperature melt pump in FIG. 1 ) is A high-temperature melt pump that transports a high-temperature melt (e.g., fuel salt 10 in FIG. 1) in a pipe (e.g., pipe 15 in FIG. 1) in a predetermined direction, The piping; A plurality of fluid diodes (e.g., fluid diode 16 in FIG. 1) provided in the middle of the piping; a pump body container (e.g., pump body container 7 in FIG. 1 ) to which the piping is connected and in which a cover gas (e.g., cover gas 17 in FIG. 1 ) is sealed and which comes into contact with the high-temperature melt; a gas vibration generator (for example, the gas vibration generator 12 in FIG. 1 ) that transmits vibrations to the high-temperature melt in the pump body container via the cover gas; The present invention is characterized in that it comprises:

[0044] According to the present invention, it is possible to realize a high-temperature melt pump that is more economical and practical and can be used in an apparatus that requires the circulation of a high-temperature melt.

[0045] In addition, (2) a high-temperature melt pump system to which the present invention is applied (for example, the high-temperature melt pump system 3 in FIG. 1) is A plurality of high-temperature melt pumps according to claim 1; a drive control device (e.g., the drive control device 8 in FIG. 1 ) that adjusts the phase of vibration generated by each of the gas vibration generating devices of the plurality of high-temperature melt pumps; The present invention is characterized in that it comprises:

[0046] According to the present invention, it is possible to realize a high-temperature melt pump system including a high-temperature melt pump that is more economical and practical and can be used in an apparatus requiring the circulation of a high-temperature melt.

[0047] In addition, (3) the present invention is applied to a high-temperature melt pump system according to (2), The present invention is characterized in that it further includes a pulsation control device (e.g., pulsation control device 9 in FIG. 1) that is arranged downstream of the piping that constitutes the multiple high-temperature melt pumps and absorbs the pulsation of the high-temperature melt to which the vibration is transmitted. The present invention is also characterized in that it further includes a method of utilizing a piston-driven gas vibration generator using a double cam mechanism instead of the triple eccentric mechanism of FIG.

[0048] According to the present invention, by arranging a pulsation control device on the downstream side of the piping, or by installing a piston-driven gas vibration generator using a double cam mechanism instead of a triple eccentric mechanism, it is possible to achieve the effect of absorbing pulsations generated in the high-temperature melt. [Explanation of symbols]

[0049] 1. Containment vessel 2. Molten Salt Reactor (Nuclear Reactor) 3. High-temperature melt pump system 4...Heat exchanger 5. Core 6 Piping 7 Pump body container 8. Drive control device 9...Pulsation adjustment device 10. Fuel salt 11 Pump body 12. Gas vibration generator 13. Cover gas 14...External environment 15 Piping 151···First pipe 151a...Piping upstream end 151b...other end 152...Second piping 152a...One end 152b Downstream end of piping 16 Fluid Diode 161 Fluid diode body 162...Flow path 163 Teardrop Loop 17. Cover gas 18. Air chamber 19 Piping 20 Piston section 21 Motor 22...metal container

Claims

1. A high-temperature melt pump that transports high-temperature melt in a pipe in a predetermined direction, The piping; A plurality of fluid diodes provided in the middle of the piping; a pump body container to which the piping is connected and in which a cover gas is sealed and which is in contact with the high-temperature melt; a gas vibration generator that transmits vibrations to the high-temperature melt in the pump body container through reciprocating motion of the cover gas generated by reciprocating drive of a piston; The present invention relates to a method for manufacturing a computer-implemented ...

2. A high-temperature melt pump, wherein the gas vibration generating device is disposed outside a containment vessel in which the plurality of fluid diodes and the pump body container are housed together with the piping, in an external environment where the temperature is lower than the temperature inside the containment vessel.

2. A plurality of high temperature melt pumps according to claim 1; a drive control device for adjusting the phase of vibration generated by each of the gas vibration generating devices of the plurality of high-temperature melt pumps; A high temperature melt pumping system comprising:

3. a pulsation control device or a piston-driven gas vibration generator using a double cam mechanism, the device being disposed downstream of the pipes constituting the plurality of high-temperature melt pumps and absorbing the pulsation of the high-temperature melt to which the vibration is transmitted; 3. The high temperature melt pumping system of claim 2.

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