A lift-type melt three-way plug directional valve with no retention zone

Abstract

This invention relates to the field of valves, specifically a lift-type, non-retention zone melt three-way plug directional valve. It includes a valve body assembly with two horizontally oriented melt outlet channels and a vertically oriented melt inlet channel. The melt inlet channel and the two melt outlet channels converge at the valve seat sealing surface of the valve body assembly, forming a "T"-shaped arrangement. An integrated plug slides vertically with the valve body assembly and seals against the valve seat sealing surface to block melt flow. When the integrated plug is in contact with the valve seat sealing surface, one end of the L-shaped channel connects to the melt inlet channel, and the other end connects to one of the two melt outlet channels. The integrated plug has an L-shaped channel and is driven by a drive unit to produce lifting and rotating motions. This invention significantly improves the sealing reliability of the three-way directional valve.

Description

Technical Field

[0001] This invention relates to the field of valves, specifically a lift-type melt three-way plug directional valve with no retention zone. Background Technology

[0002] Melt three-way reversing valves are mainly used in polymer plants such as PET, PBT, PTA, Nylon6, and Nylon66. They are generally installed at the inlet and outlet of the main equipment (such as polymerization reactors, melt filters, melt pumps, etc.) to open or close the channel, switch the flow of the medium from one device to another, and realize free switching between two backup devices.

[0003] Currently, the commonly used melt three-way directional valve adopts a double-stem Y-type plunger / valve disc structure, which is a combination of the Y-type single plunger / valve disc melt valve. In one valve body, there are two independent valve cores, valve seats and transmission mechanisms, which can realize the switching of two valve flow channels to open and close. Its structure is relatively complex, and its size and weight are large. After long-term use, the sealing surface is prone to large wear, resulting in poor sealing reliability. Therefore, it is urgent to solve this problem. Summary of the Invention

[0004] To avoid and overcome the technical problems existing in the prior art, this invention provides a lift-type melt-free three-way plug directional valve. This invention significantly improves the sealing reliability of the three-way directional valve.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A lift-type melt three-way plug directional valve with no retention zone includes a valve body assembly. The valve body assembly has two melt outlet channels opened in the horizontal direction and a melt inlet channel opened in the vertical direction. The melt inlet channel and the two melt outlet channels intersect at the valve seat sealing surface of the valve body assembly, so that the channels form a "T" shape arrangement.

[0007] After the integrated plug slides and engages with the valve body assembly along the vertical direction, it seals against the valve seat sealing surface to isolate the flow of melt. When the integrated plug seals against the valve seat sealing surface, one end of the L-shaped channel is connected to the melt inlet channel, and the other end of the L-shaped channel is connected to one of the two melt outlet channels. The integrated plug has an L-shaped channel and is driven by the drive unit to generate lifting and rotating motions. After the integrated plug disengages from the valve seat sealing surface through the lifting motion, it rotates to switch the connected melt outlet channel.

[0008] As a further aspect of the present invention: the driving unit includes an upper valve stem coaxially fixed with the integrated stopcock, and a hollow lifting shaft sleeved outside the upper valve stem and coaxially rotating with the upper valve stem; an actuator bracket for installing the valve stem nut and gear transmission mechanism is fixed on the valve body assembly, and the upper valve stem can slide vertically along the actuator bracket while forming an anti-rotation engagement with the actuator bracket; the lifting handwheel is geared to the valve stem nut through the gear transmission mechanism to drive the valve stem nut to rotate freely within the actuator bracket, and while the valve stem nut is rotating freely, it engages with the hollow lifting shaft threadedly to drive the hollow lifting shaft to produce a lifting action.

[0009] As a further aspect of the present invention: the mounting step at the bottom of the upper valve stem and the hollow lifting shaft are coaxially rotated together by a thrust bearing; the outer rings of the adjacent ends of the upper valve stem and the integrated plug are respectively provided with valve stem threads and plug threads; the clamping block is sleeve-shaped, and its inner ring is provided with threads to lock and fix it with the positioning groove of the upper valve stem and the plug thread of the integrated plug, so as to restrict relative rotation between the upper valve stem and the integrated plug.

[0010] As a further aspect of the present invention: the clamping block has a split structure, which is locked and fixed by bolts after being closed; the mating surfaces of the upper valve stem and the integrated plug are respectively provided with positioning grooves and plug tenons, and are positioned by plug tenons being inserted into the positioning grooves; the end face of the hollow lifting shaft adjacent to the actuator bracket is provided with anti-rotation teeth in the radial direction, and the actuator bracket is provided with anti-rotation grooves in the vertical direction corresponding to the positions of the anti-rotation teeth. The anti-rotation teeth of the hollow lifting shaft are inserted into the anti-rotation grooves of the actuator bracket to restrict the rotation of the hollow lifting shaft.

[0011] As a further embodiment of the present invention: the end of the upper valve stem away from the integrated plug extends to the outside of the hollow lifting shaft and is driven to rotate by the reversing mechanism. The movement trajectory of the reversing mechanism avoids the movement trajectory of the lifting handwheel. The reversing mechanism includes a horizontally arranged reversing handle, which is fixed on the axial nut and locked to the upper valve stem by the axial nut through a thread. The upper valve stem and the axial nut are prevented from loosening by an elastic cylindrical pin.

[0012] As a further embodiment of the present invention: a bracket flange is fixed on the actuator bracket and coaxially sleeved on the outer ring of the hollow lifting shaft. The bracket flange has positioning holes symmetrically arranged with respect to the upper valve stem and with a phase difference of 180 degrees. A plug shaft that can be inserted and removed in the vertical direction is arranged on the reversing handle. When the integrated plug is connected to one of the two heat medium outlet channels, the plug shaft corresponds exactly to the position of one of the positioning holes of the bracket flange.

[0013] As a further aspect of the present invention: a valve seat bushing is installed at the intersection of the melt inlet channel and the two melt outlet channels inside the valve body assembly. The melt inlet channel and the two melt outlet channels are connected by a transverse through hole and a longitudinal through hole in the valve seat bushing. The valve seat sealing surface is opened inside the valve seat bushing. An integrated plug is inserted into the valve seat bushing in the vertical direction and slides in fit with the valve seat bushing. An anti-rotation pin groove is opened on the valve seat bushing. The valve body assembly is fixed by the anti-rotation pin and the anti-rotation pin groove to restrict the rotation of the valve seat bushing.

[0014] As a further aspect of the present invention: a packing seal system is arranged inside the valve seat bushing to improve the sealing performance of the valve seat bushing and the contact surface of the integrated plug; the packing seal system is locked and fixed to the valve body assembly by a packing preload bolt, and a disc spring is installed on the packing preload bolt by a disc spring guide sleeve. The disc spring applies an elastic force toward the valve body assembly to the packing seal system to prevent the packing preload from loosening. The packing of the packing seal system is a composite packing.

[0015] As a further embodiment of the present invention: a jacket is arranged outside the valve body assembly, and the jacket and the valve body assembly enclose a jacket cavity for the flow of the heating medium. The melt inlet channel and the two melt outlet channels are both located in the jacket cavity, so that the melt exchanges heat with the heating medium and keeps it warm when it flows.

[0016] As a further embodiment of the present invention: the L-shaped channel of the integrated plug is streamlined, and the opening of the mating surface between the integrated plug and the melt outlet channel is an irregular opening. The opening of the irregular opening is ellipsoidal or butterfly-shaped, and a scraper is provided on the outer edge of the irregular opening to scrape off the molten coke on the valve seat sealing surface.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. This invention adopts an L-shaped channel hard-seal plug design. After lifting the plug, the plug is rotated 180° to achieve flow channel switching. The entire reversing valve has only a single valve core, a single valve seat, and a single actuator. The structure is simple and compact, requiring little installation space. The reversing process is divided into three actions: lifting, rotating, and lowering. During reversing, the valve core sealing surface of the integrated plug and the valve seat sealing surface of the valve seat bushing are completely disengaged, and the sealing surface is not worn, ensuring long-term reliable use of the seal and greatly improving the sealing reliability of the three-way reversing valve.

[0019] 2. Through the cooperation of the reversing mechanism and the positioning mechanism, the present invention can manually and quickly realize the functions of lifting, rotating and precise positioning. When the valve is reversed, the valve core sealing surface and the valve seat sealing surface are completely disengaged. The reversing mechanism only needs to overcome the frictional resistance torque of the packing, and the required operating torque is small. At the same time, the lifting stroke of the integrated plug is small. Before and after reversing, the L-shaped channel of the integrated plug is precisely aligned with the flow channel on the corresponding side of the valve body assembly, which can realize the accurate switching of the flow channel.

[0020] 3. The present invention adopts a streamlined internal flow channel with no stagnation area, no abrupt changes in the flow channel cross section, low flow resistance and low pressure loss; the valve body assembly is equipped with a jacket for heat preservation, which further ensures the flow rate of high viscosity melt and effectively avoids problems such as degradation, color change and quality decline caused by excessive melt residence time.

[0021] 4. This invention achieves the removal of molten coke on the valve seat bushing sealing surface during the reversing process by setting several scraping blades at the edge of the irregular opening of the L-shaped channel, ensuring reliable long-term sealing. In achieving a simple and reliable reversing function, a composite sealing structure of packing soft seal and conical wedge hard seal is set on the integrated plug. During the reversing process, the packing soft seal is used to prevent external leakage, and during the non-reversing process, the conical hard seal is used to prevent internal and external leakage, resulting in excellent sealing performance. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention.

[0023] Figure 2 for Figure 1 A schematic diagram of the internal structure of the valve body assembly under the specified conditions.

[0024] Figure 3 This is an isometric view of the valve seat bushing in this invention.

[0025] Figure 4 This is a cross-sectional view of the valve seat bushing in this invention.

[0026] Figure 5 This is a schematic diagram of the connection between the upper valve stem and the integrated plug in this invention.

[0027] Figure 6 This is a schematic diagram of the positioning mechanism of the present invention.

[0028] Figure 7 This is a schematic diagram of the hollow lifting shaft in this invention.

[0029] Figure 8 This is a schematic diagram of the structure of the actuator support in this invention.

[0030] Figure 9a This is a front view of a one-piece plunger with a butterfly-shaped opening.

[0031] Figure 9b This is an isometric view of a one-piece plunger with a butterfly-shaped opening.

[0032] Figure 9c This is a cross-sectional view of a one-piece plunger with a butterfly-shaped opening.

[0033] Figure 10a This is a front view of a one-piece plunger with an irregularly shaped opening that is ellipsoidal.

[0034] Figure 10b This is an axonometric view of a monolithic plunger with an ellipsoidal opening.

[0035] Figure 10c This is a cross-sectional view of a one-piece plunger with an ellipsoidal opening.

[0036] In the picture:

[0037] 10. Valve body assembly; 11. First heat medium jacketed flange; 12. Second heat medium jacketed flange;

[0038] 13. Third heat medium jacket flange; 14. Left side horizontal heat medium jacket; 15. Fourth heat medium jacket flange; 16. Vertical upward heat medium jacket; 17. Right side horizontal heat medium jacket; 18. Vertical downward heat medium jacket;

[0039] 19a. First valve body flange; 19b. Second valve body flange; 19c. Third valve body flange;

[0040] 20. Valve seat bushing; 21. Axial waterline groove; 22. Circumferential waterline groove; 23. Anti-rotation pin groove;

[0041] 24. Valve seat sealing surface; 25. Valve seat outer cylindrical surface; 26. Valve seat cylindrical inner bore;

[0042] 30. One-piece stopcock; 30a. Lower scraper blade; 30b. Right scraper blade; 30c. Upper scraper blade;

[0043] 30d, outer cylindrical surface of the plug; 30e, left scraper; 30f, valve core sealing surface; 30g, irregular opening; 30h, L-shaped channel; 30i, plug tenon; 30j, plug thread;

[0044] 40. Packing seal system; 41. Packing preload bolts; 42. Disc springs;

[0045] 43. Disc spring guide sleeve; 44. Combined packing;

[0046] 50. Hollow lifting shaft; 50a. Anti-rotation gear; 50b. Mounting hole; 50c. Lifting shaft thread;

[0047] 60. Gear transmission mechanism; 61. Valve stem nut; 62. Lifting handwheel;

[0048] 70. Reversing mechanism; 71. Support flange; 72. Axial nut;

[0049] 73. Reversing handle; 74. Spring-loaded cylindrical pin;

[0050] 80. Positioning mechanism; 81. Insert shaft; 82. Support ring; 83. Compression spring;

[0051] 84. Guide ring; 85. Locking nut; 86. Round pin;

[0052] 87. Flexible round pin; 88. Flange;

[0053] 90. Upper valve stem; 90a. Valve stem thread; 90b. Positioning groove;

[0054] 100. Thrust bearing; 110. Clamping block;

[0055] 120. Actuator bracket; 120a. Anti-rotation groove; 120b. Upper flange; 120c. Lower flange;

[0056] 130. Prevent resale. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] Please see Figures 1-10c In this embodiment of the invention, a lift-type non-retention zone melt three-way plug directional valve includes a valve body assembly 10. The valve body assembly 10 has two horizontally oriented melt outlet channels and a vertically oriented melt inlet channel. A cylindrical cavity is formed on the valve body assembly 10 from top to bottom for inserting and fixing a valve seat bushing 20. The valve seat bushing 20 and the valve body assembly 10 can be integrally fixed or designed separately. When the valve seat bushing 20 and the valve body assembly 10 are integrally designed, hard alloy can be welded onto the valve seat sealing surface. Meanwhile, the upper valve stem 90 and the integral plug 30 are connected by threads, and an anti-rotation cylindrical pin is provided to prevent the threads from loosening.

[0059] The valve seat bushing 20 has a transverse through hole and a longitudinal through hole to connect the melt inlet channel and the two melt outlet channels. An integrated plug 30 is inserted into the valve seat bushing 20 from top to bottom and can slide against the valve seat bushing 20 in the vertical direction. The valve seat bushing 20 has a radially formed anti-rotation groove 23. The valve body assembly 10 is fixed to the anti-rotation groove 23 by inserting an anti-rotation pin 130 into the anti-rotation groove 23 to restrict the rotation of the valve seat bushing 20. The valve seat bushing 20 and the valve body assembly 10 achieve an interference fit seal through hot or cold fitting. The outer cylindrical surface 25 of the valve seat bushing 20 can be further provided with four axial waterline grooves 21 in the vertical direction and six circumferential waterline grooves 22 to further improve the anti-rotation and sealing effects.

[0060] The valve body assembly 10 is provided with a first valve body flange 19a, a second valve body flange 19b, and a third valve body flange 19c, serving as three pipe ports for the molten medium to enter and exit. The arrangement of the first heat medium jacket flange 11, the second heat medium jacket flange 12, the third heat medium jacket flange 13, the left horizontal heat medium jacket 14, the fourth heat medium jacket flange 15, the vertically upward heat medium jacket 16, the right horizontal heat medium jacket 17, and the vertically downward heat medium jacket 18, together with the valve body assembly 10, forms a jacket cavity, allowing heat medium to be introduced into the jacket cavity through the flange ports. The heat medium can be a flowing heat medium such as steam, heat transfer oil, or biphenyl-diphenyl ether, which can insulate the valve to maintain the temperature of the molten medium inside the valve and ensure the flow rate of the molten medium.

[0061] The valve core sealing surface 30f of the integrated plug 30 and the valve seat sealing surface 24 of the valve seat bushing 20 achieve a forced hard seal under the preload provided by the gear transmission mechanism 60. The L-shaped channel 30h of the integrated plug 30 is then reversed 180 degrees via the reversing mechanism 70 and the positioning mechanism 80. The valve core sealing surface 30f of the integrated plug 30 and the valve seat sealing surface 24 are fitted together to seal and isolate the melt flow. The integrated plug 30 has an L-shaped channel 30h. When the integrated plug 30 and the valve seat sealing surface 24 are fitted together, one end of the L-shaped channel 30h is connected to the melt inlet channel, and the other end is selectively connected to one of the two melt outlet channels. Driven by the drive unit, the integrated plug 30 can generate lifting and rotating movements. After the integrated plug 30 disengages from the valve seat sealing surface 24 through lifting movement, it rotates to switch the connected melt outlet channel.

[0062] The mating surface between the L-shaped channel 30h and the melt outlet channel is an irregularly shaped opening 30g, the cross-section of which is preferably butterfly-shaped or ellipsoidal. The edge of the irregularly shaped opening 30g is provided with an upper scraper 30c, a lower scraper 30a, a left scraper 30e, and a right scraper 30b, which scrape off the coking of the melt on the valve seat sealing surface 24 during the lifting and rotating process, ensuring long-term sealing. The cavity of the L-shaped channel 30h is streamlined.

[0063] To further improve sealing, a packing seal system 40 is provided between the outer cylindrical surface 30d of the integrated plug 30 and the inner cylindrical bore 26 of the valve seat bushing 20. The packing seal system 40 is locked and fixed to the valve body assembly 10 by a packing preload bolt 41. A disc spring 42 is installed on the packing preload bolt 41 through a disc spring guide sleeve 43. The disc spring 42 applies an elastic force toward the valve body assembly 10 to the packing seal system 40 to prevent the packing preload from loosening. The packing of the packing seal system 40 is a composite packing 44.

[0064] The integrated plug 30 and the upper valve stem 90 are rigidly connected by the clamping block 110. The upper plug thread 30i of the integrated plug 30 and the lower valve stem thread 90a of the upper valve stem 90 are engaged with the internal thread of the clamping block 110, and the threads are tightened by the bolts on the clamping block 110 to prevent axial relative movement. The plug tenon 30h on the upper part of the integrated plug 30 and the positioning groove 90b on the lower part of the upper valve stem 90 are engaged to prevent circumferential relative movement.

[0065] The actuator bracket 120 is bolted to the gear transmission mechanism via the upper flange 120b and bolted to the valve body assembly 10 via the lower flange 120c. A hollow lifting shaft 50 is sleeved around the upper valve stem 90 and rotates coaxially with it. Preferably, the hollow lifting shaft 50 is coaxially rotated with the upper valve stem 90 via a thrust bearing 100 through the mounting step at the bottom of the upper valve stem 90. The hollow lifting shaft 50, driven by the thrust bearing 100, synchronously raises and lowers the upper valve stem 90 and the integrated stopcock 30.

[0066] The upper valve stem 90 can slide vertically along the actuator bracket 120 while simultaneously forming an anti-rotation engagement with the actuator bracket 120. The end face of the hollow lifting shaft 50 adjacent to the actuator bracket 120 is radially provided with anti-rotation teeth 50a. The actuator bracket 120 has anti-rotation grooves 120a corresponding to the positions of the anti-rotation teeth 50a along the vertical direction. The anti-rotation teeth 50a of the hollow lifting shaft 50 are inserted into the anti-rotation grooves 120a of the actuator bracket 120 to restrict the rotation of the hollow lifting shaft 50. Preferably, there are four sets of anti-rotation teeth 50a and anti-rotation grooves 120a, which engage to achieve anti-rotation operation. The hollow lifting shaft 50 has a central mounting hole for the upper valve stem 90 to pass through, and is threaded with the valve stem nut 61 via the lifting shaft thread 50c.

[0067] The lifting handwheel 62 is driven by the gear transmission mechanism 60 to drive the valve stem nut 61 to rotate freely within the actuator bracket 120. While the valve stem nut 61 is rotating freely, it engages with the hollow lifting shaft 50 to drive the hollow lifting shaft 50 to produce a lifting action.

[0068] The end of the upper valve stem 90 away from the integrated cock 30 extends to the outside of the hollow lifting shaft 50 and is driven to rotate by the reversing mechanism 70. The movement trajectory of the reversing mechanism 70 avoids the movement trajectory of the lifting handwheel 62. The reversing mechanism 70 includes a bracket flange 71, an axial nut 72, a reversing handle 73, and an elastic cylindrical pin 74. The reversing handle 73 is fixed on the axial nut 72 and is threadedly locked to the upper valve stem 90 by the axial nut 72. The upper valve stem 90 and the axial nut 72 are prevented from loosening by the elastic cylindrical pin 74. After the integrated cock 30 is lifted, the reversing handle 73 drives the upper valve stem 90 to rotate 180 degrees through the axial nut 72, thereby realizing the 180-degree reversal of the L-shaped channel 30h of the integrated cock 30.

[0069] The bracket flange 71 is coaxially fixed to the outer ring of the hollow lifting shaft 50. Positioning holes symmetrically arranged with respect to the upper valve stem 90 and with a phase difference of 180 degrees are provided on the bracket flange 71. A plug shaft 81, which can be inserted and removed vertically, is arranged on the reversing handle 73. When the integrated stopcock 30 is connected to one of the two heat medium outlet channels, the plug shaft 81 corresponds precisely to one of the positioning holes on the bracket flange 71. The positioning mechanism 80 consists of the plug shaft 81, support ring 82, compression spring 83, guide ring 84, locking nut 85, round pin 86, elastic round pin 87, and flange 88. The small cylinder at the lower part of the plug shaft 81, under the action of the compression spring 83, is inserted into the positioning hole of the flange 88 and abuts against the flange 88. The flange 88 can be designed independently of the bracket flange 71, or the positioning hole can be directly provided on the bracket flange 71 to position the plug shaft 81. After the integrated cock 30 is raised at least 2mm, the insert shaft 81 can be completely pulled out using the elastic pin 87, and after rotating 90 degrees, the cylindrical pin 86 is held in place at the upper end of the guide ring 84. At this time, the rotation of the reversing handle 73 drives the integrated cock 30 to rotate 180 degrees. The insert shaft 81 is further raised and rotated 90 degrees in the opposite direction. After being released, the insert shaft 81 is inserted into another positioning hole in the flange 88 under the action of the compression spring 83, thereby achieving precise positioning during reversal and ensuring precise alignment between the L-shaped channel 30h on the integrated cock 30 and one of the sets of melt outlet channels of the valve body assembly 10.

[0070] When switching the melt flow direction, the specific steps may include the following:

[0071] S1. Connect the L-shaped channel 30h of the integrated plug 30 to the B3 port and B1 port of the valve body assembly 10, and completely isolate the high-temperature and high-pressure molten medium inside the valve from the B2 port.

[0072] S2. Upon receiving the process switching instruction, firstly, rotate the lifting handwheel 62 of the gear transmission mechanism 60 counterclockwise to raise the integrated plug 30 by at least 2mm. At this time, the valve core sealing surface 30f of the integrated plug 30 is completely disengaged from the valve seat sealing surface 24 of the valve seat bushing 20. Then, pull out the insertion shaft 81 of the positioning mechanism 80 until it is disengaged from the positioning hole of the flange 88, and rotate the elastic pin 87 90 degrees clockwise. The pin 87 then rests on the upper end of the guide ring 84 through the pin 86. At this time, the lower end face of the insertion shaft 81 is higher than the upper end face of the flange 88. Then, rotate the reversing handle 73 of the reversing mechanism 70 180 degrees clockwise. At this time, the L-shaped channel 30h of the integrated plug 30 has also rotated 180 degrees clockwise. Pull out the insertion shaft 81 further, rotate the elastic pin 87 90 degrees counterclockwise, and under the action of the compression spring 83, the insertion shaft 81 is reinserted into the other positioning hole of the flange 88. Then rotate the lifting handwheel 62 clockwise to lower the valve core sealing surface 30f of the integrated plug 30 to fully press against the valve seat sealing surface 24 of the valve seat bushing 20, thereby achieving a tight seal.

[0073] S3. After the reversal is completed, the L-shaped channel 30h of the integrated plug 30 connects the B2 port and B1 port of the valve body assembly 10, and completely isolates the high-temperature and high-pressure molten medium inside the valve from the B3 port. At this time, the reversal is completed.

[0074] By repeating the above steps, the rapid cyclic switching function between the two states of this invention can be achieved.

[0075] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0076] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

Claims

1. A lift-type non-retention zone melt three-way plug directional valve, characterized in that, The valve body assembly (10) includes two melt outlet channels in the horizontal direction and a melt inlet channel in the vertical direction. The melt inlet channel and the two melt outlet channels intersect at the valve seat sealing surface (24) of the valve body assembly (10) so that each channel is arranged in a "T" shape. After the integrated plug (30) slides and engages with the valve body assembly (10) in the vertical direction, it fits and seals with the valve seat sealing surface (24) to block the flow of melt. An L-shaped channel (30h) is provided on the integrated plug (30). When the integrated plug (30) fits and seals with the valve seat sealing surface (24), one end of the L-shaped channel (30h) is connected to the melt inlet channel, and the other end of the L-shaped channel (30h) is connected to one of the two melt outlet channels. The integrated plug (30) is driven by the drive unit to generate lifting and rotating motion. After the integrated plug (30) disengages from the valve seat sealing surface (24) through the lifting motion, it rotates to switch the connected melt outlet channel. A valve seat bushing (20) is installed at the junction of the melt inlet channel and the two melt outlet channels inside the valve body assembly (10). The melt inlet channel and the two melt outlet channels are connected by a transverse through hole and a longitudinal through hole in the valve seat bushing (20). The valve seat sealing surface (24) is opened in the valve seat bushing (20). An integrated plug (30) is inserted into the valve seat bushing (20) in the vertical direction and slides with the valve seat bushing (20). An anti-rotation pin groove (23) is opened on the valve seat bushing (20). The valve body assembly (10) is fixed by inserting the anti-rotation pin (130) into the anti-rotation pin groove (23) to restrict the rotation of the valve seat bushing (20). A packing seal system (40) is arranged inside the valve seat bushing (20) to improve the sealing performance of the contact surface between the valve seat bushing (20) and the integrated plug (30); the packing seal system (40) is locked and fixed to the valve body assembly (10) by a packing preload bolt (41), and a disc spring (42) is installed on the packing preload bolt (41) through a disc spring guide sleeve (43). The disc spring (42) applies an elastic force toward the valve body assembly (10) to the packing seal system (40) to prevent the packing preload from loosening. The packing of the packing seal system (40) is a combination packing (44). The valve body assembly (10) is provided with a jacket. The jacket and the valve body assembly (10) enclose a jacket cavity for the flow of the heating medium. The melt inlet channel and the two melt outlet channels are both located in the jacket cavity so that the melt can exchange heat with the heating medium and keep it warm when it flows. The L-shaped channel (30h) of the integrated plug (30) is streamlined. The opening of the mating surface between the integrated plug (30) and the melt outlet channel is a non-circular opening (30g). The opening of the non-circular opening (30g) is ellipsoidal or butterfly-shaped. The outer edge of the non-circular opening (30g) is provided with a scraper to scrape off the melt coking on the valve seat sealing surface (24).

2. The lift-type non-retention zone melt three-way plug directional valve according to claim 1, characterized in that, The drive unit includes an upper valve stem (90) coaxially fixed with the integrated stopcock (30), and a hollow lifting shaft (50) sleeved on the upper valve stem (90) and coaxially rotating with the upper valve stem (90); an actuator bracket (120) for installing the valve stem nut (61) and the gear transmission mechanism (60) is fixed on the valve body assembly (10). The upper valve stem (90) can slide vertically along the actuator bracket (120) and form an anti-rotation fit with the actuator bracket (120); the lifting handwheel (62) is geared to the valve stem nut (61) through the gear transmission mechanism (60) to drive the valve stem nut (61) to rotate freely in the actuator bracket (120). While the valve stem nut (61) is rotating freely, it is threadedly engaged with the hollow lifting shaft (50) to drive the hollow lifting shaft (50) to produce a lifting action.

3. A lift-type non-retention zone melt three-way plug directional valve according to claim 2, characterized in that, The mounting step at the bottom of the upper valve stem (90) and the hollow lifting shaft (50) are coaxially rotated through the thrust bearing (100). The outer rings of the adjacent ends of the upper valve stem (90) and the integrated plug (30) are respectively provided with valve stem threads (90a) and plug threads (30j). The clamping block (110) is sleeve-shaped, and its inner ring is provided with threads so as to lock and fix it with the positioning groove (90b) of the upper valve stem (90) and the plug thread (30j) of the integrated plug (30) to restrict relative rotation between the upper valve stem (90) and the integrated plug (30).

4. A lift-type non-retention zone melt three-way plug directional valve according to claim 3, characterized in that, The clamping block (110) has a split structure and is locked and fixed by bolts after being closed. The mating surfaces of the upper valve stem (90) and the integrated plug (30) are respectively provided with positioning grooves (90b) and plug tenons (30i), and are positioned by plug tenons (30i) and positioning grooves (90b). The end face of the hollow lifting shaft (50) adjacent to the actuator bracket (120) is provided with anti-rotation teeth (50a) in the radial direction. The actuator bracket (120) is provided with anti-rotation grooves (120a) in the vertical direction corresponding to the position of the anti-rotation teeth (50a). The anti-rotation teeth (50a) of the hollow lifting shaft (50) are inserted into the anti-rotation grooves (120a) of the actuator bracket (120) to restrict the rotation of the hollow lifting shaft (50).

5. A lift-type non-retention zone melt three-way plug directional valve according to any one of claims 2 to 4, characterized in that, The upper valve stem (90) extends from the end away from the integrated plug (30) to the hollow lifting shaft (50) and is driven to rotate by the reversing mechanism (70). The movement trajectory of the reversing mechanism (70) avoids the movement trajectory of the lifting handwheel (62). The reversing mechanism (70) includes a horizontally arranged reversing handle (73). The reversing handle (73) is fixed on the axial nut (72) and locked to the upper valve stem (90) by the axial nut (72) thread. The upper valve stem (90) and the axial nut (72) are prevented from loosening by an elastic cylindrical pin (74).

6. A lift-type non-retention zone melt three-way plug directional valve according to claim 5, characterized in that, A bracket flange (71) is fixed on the actuator bracket (120) and coaxially sleeved on the outer ring of the hollow lifting shaft (50). The bracket flange (71) has positioning holes symmetrically arranged about the upper valve stem (90) with a phase difference of 180 degrees. A plug shaft (81) that can be inserted and removed in the vertical direction is arranged on the reversing handle (73). When the integrated plug (30) is connected to one of the two heat medium outlet channels, the plug shaft (81) corresponds exactly to one of the positioning holes of the bracket flange (71).

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