A direct freezing crystallization device

Abstract

A direct freezing crystallization device belongs to the field of freezing crystallization, including a tank body, a plurality of supporting legs fixedly installed on the tank body, a liquid inlet pipe connected to the tank body, a ball valve connected to the bottom of the tank body, a heat exchange coil arranged in the tank body, the inlet end and the outlet end of the heat exchange coil respectively extending to the outside of the tank body, a vertical shaft and a driving mechanism for driving the vertical shaft to rotate are arranged in the tank body, a plurality of stirring rods are fixedly installed on the vertical shaft, a vertical plate is connected to the vertical shaft for rotation, and a through groove is provided on the vertical plate corresponding to the stirring rod. The present invention has a simple structure and an ingenious design. When the stirring rod rotates forward and the vertical plate does not rotate, the stirring rod stirs the solution, so that the solution heat exchange is more uniform, and the heat exchange efficiency is improved. When the crystal is precipitated, the stirring rod and the whole plate composed of the vertical plate rotate in the opposite direction together, thereby promoting the crystal to revolve in the tank body, and under the guidance of the spiral heat exchange coil, the crystal is simultaneously transported downward, so as to be pushed to the bottom of the tank body for discharge, which can meet actual needs and is suitable for promotion.

Description

Technical Field

[0001] The invention belongs to the field of freezing crystallization, in particular to a direct freezing crystallization device. Background Art

[0002] At present, in the process of producing potassium nitrate by double decomposition of magnesium nitrate oxide in domestic potassium nitrate production enterprises, the final separation of potassium nitrate needs to be frozen in a mixed solution of potassium nitrate and magnesium chloride, so that the potassium nitrate crystallizes into a solid. The existing freezing crystallization equipment has a large number of heat exchange coils in the tank body, and a large number of crystals are formed in the tank body, and the crystals will adhere to the heat exchange coils, making it difficult for the crystals to be discharged from the tank body only under the action of gravity. Therefore, we designed a freezing crystallization device that is easy to discharge. Summary of the invention

[0003] The present invention provides a direct freezing crystallization device to solve the defects in the prior art.

[0004] The present invention is achieved through the following technical solutions:

[0005] A direct freezing crystallization device comprises a tank body, a plurality of supporting legs are fixedly installed on the tank body, a liquid inlet pipe is connected and installed on the tank body, a ball valve is connected and installed at the bottom of the tank body, a heat exchange coil is arranged in the tank body, the inlet end and the outlet end of the heat exchange coil extend to the outside of the tank body respectively, a vertical shaft and a driving mechanism for driving the vertical shaft to rotate are arranged in the tank body, a plurality of stirring rods are fixedly installed on the vertical shaft, the vertical shaft is rotatably connected to a vertical plate, a through groove is provided on the vertical plate corresponding to the stirring rod, the stirring rod can seal the corresponding through groove, so that it and the vertical plate form a complete plate, the vertical shaft cannot drive the vertical plate to rotate when rotating in the forward direction, and the vertical shaft can drive the vertical plate to rotate together when rotating in the reverse direction.

[0006] In the direct freezing crystallization device as described above, the driving mechanism includes a motor, the motor is fixedly mounted on the tank body, and the output shaft of the motor is fixedly connected to the vertical shaft.

[0007] In a direct freezing crystallization device as described above, the vertical axis is divided into multiple sections, and two adjacent sections of the vertical axis are connected together by a connecting structure. The connecting structure includes a groove, and one section of the vertical axis is rotatably installed in the groove of an adjacent section through a bearing. A first annular groove is respectively provided in the groove, and a protrusion is provided in the first annular groove. One side of the protrusion is an inclined surface, and the other side is a vertical surface. When the first spring telescopic rods are all against the corresponding inclined surfaces of the protrusions, the stirring rods on the vertical axis are distributed in a spiral, and a first spring telescopic rod is slidably provided in the first annular groove. The first spring telescopic rod is fixedly installed on an adjacent section of the vertical axis, and the elastic force of the first spring telescopic rod increases with the height of each section of the vertical axis.

[0008] In a direct freezing crystallization device as described above, a second spring telescopic rod is fixedly installed on the fourth section of the vertical axis, a second annular groove is opened on the vertical plate, the second spring telescopic rod is slidably connected to the second annular groove, and a section of the bottom surface of the second annular groove is stepped.

[0009] In the direct freezing crystallization device as described above, the bottom of the tank is in an inverted cone shape.

[0010] In a direct freezing crystallization device as described above, the heat exchange coil is connected to an external refrigeration system, the refrigeration system includes a compressor, the input end of the compressor is connected to the outlet of the heat exchange coil, the output end of the compressor is connected to the input end of the outdoor condenser, the output end of the outdoor condenser is connected to the input end of the liquid storage device, the output end of the liquid storage device is connected to the input end of the throttle, the output end of the throttle is connected to the input end of the refrigeration pump, and the output end of the refrigeration pump is connected to the inlet of the heat exchange coil.

[0011] The advantages of the present invention are: the present invention has a simple structure and an ingenious design. When the stirring rod rotates in the forward direction and the vertical plate does not rotate, the stirring rod stirs the solution, making the heat exchange of the solution more uniform and improving the heat exchange efficiency. When crystals are precipitated, the stirring rod and the entire plate composed of the vertical plate rotate in the reverse direction together, thereby pushing the crystals to revolve in the tank body, and under the guidance of the spiral heat exchange coil, the crystals are simultaneously transported downward, so as to be pushed to the bottom of the tank body for discharge, which can meet actual needs and is suitable for promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0013] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 yes Figure 1 a cross-sectional view of the top view; Figure 3 is a schematic diagram of the stirring rod being unfolded; Figure 4 It is a schematic diagram of the spiral distribution of the stirring rod on the vertical axis; Figure 5 is a schematic diagram of the expansion of the first annular groove; Figure 6 is a schematic diagram of the second annular groove being expanded; Figure 7 It is a schematic diagram of the bottom end of the first section of the vertical axis; Figure 8 yes Figure 1 Partial enlarged view of Ⅰ; Fig. 9 yes Figure 1 Ⅱ partial enlarged view; Fig.10 It is a schematic diagram of the refrigeration system.

[0014] Figure numerals: 1, tank body, 2, supporting leg, 3, liquid inlet pipe, 4, ball valve, 5, heat exchange coil, 6, motor, 7, vertical axis, 8, stirring rod, 9, vertical plate, 10, through groove, 20, groove, 21, first annular groove, 22, protrusion, 23, first spring telescopic rod, 30, second spring telescopic rod, 31, second annular groove. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] A direct freezing crystallization device, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10As shown, it includes a tank body 1, several supporting legs 2 are fixedly installed on the tank body 1, a liquid inlet pipe 3 is connected and installed on the tank body 1, a ball valve 4 is connected and installed at the bottom of the tank body 1, a heat exchange coil 5 is arranged in the tank body 1, and the inlet end and the outlet end of the heat exchange coil 5 extend to the outside of the tank body 1 respectively, and it is characterized in that: a vertical shaft 7 and a driving mechanism for driving the vertical shaft 7 to rotate are arranged in the tank body 1, and several stirring rods 8 are fixedly installed on the vertical shaft 7. In this embodiment, there are four layers of stirring rods 8, each layer has two stirring rods 8, and they are symmetrically distributed on the left and right, the vertical shaft 7 is rotatably connected to the vertical plate 9, and a vertical groove is provided on the vertical plate 9. The vertical shaft 7 is located in the vertical groove and is rotatably connected to the inner wall of the vertical groove through a bearing, and a through groove 10 is provided on the vertical plate 9 corresponding to the stirring rod 8, and the stirring rod 8 can seal the corresponding through groove 10, so that it and the vertical plate 9 form a complete plate, and the vertical shaft 7 cannot drive the vertical plate 9 to rotate when it rotates forward, and the vertical shaft 7 can drive the vertical plate 9 to rotate together when it rotates reversely. The present invention has a simple structure and an ingenious design. When the stirring rod 8 rotates forward and the vertical plate 9 does not rotate, the stirring rod 8 stirs the solution to make the heat exchange of the solution more uniform and improve the heat exchange efficiency. When crystals are precipitated, the stirring rod 8 and the entire plate composed of the vertical plate 9 rotate in the opposite direction, thereby pushing the crystals to revolve in the tank body 1, and under the guidance of the spiral heat exchange coil 5, the crystals are simultaneously transported downward, so as to be pushed to the bottom of the tank body 1 for discharge, which can meet actual needs and is suitable for promotion. When in use, the inlet and outlet of the heat exchange coil 5 are connected to the refrigeration equipment, and then the pipeline for conveying the potassium nitrate magnesium chloride solution is connected to the liquid inlet pipe 3 and fixed by bolts and flanges. Subsequently, the potassium nitrate magnesium chloride solution is passed into the tank body 1, and the running heat exchange coil 5 is used to cool the potassium nitrate magnesium chloride solution. At the same time, the vertical shaft 7 is driven by the driving mechanism to rotate forward, and the vertical plate 9 does not rotate at this time. The vertical shaft 7 drives the stirring rod 8 to stir the potassium nitrate magnesium chloride solution, so that the potassium nitrate magnesium chloride solution is evenly in contact with the heat exchange coil 5, so that the cooling is more uniform and crystallization is convenient. In addition, the relative rotation between the vertical plate 9 and the stirring rod 8 is also conducive to the stirring of the solution. In one step, the solution is evenly heat exchanged to improve the heat exchange efficiency, and the vertical plate 9 and the stirring rod 8 clean each other to reduce the crystals adhering to the vertical plate 9 and the stirring rod 8. When the crystal precipitation is saturated, there are a large number of crystals in the tank body 1. The driving mechanism drives the vertical shaft 7 to rotate in the opposite direction, so that the stirring rod 8 and the vertical plate 9 form a complete plate and rotate in the opposite direction with the vertical shaft 7. The vertical plate 9 promotes the crystals in the tank body 1 to revolve, and under the spiral guidance of the spiral heat exchange coil 5, the crystals move downward, thereby facilitating the crystals to move in the direction of the ball valve 4 for discharge. At the same time, when the vertical plate 9 rotates, it can scrape off the crystals on the inside of the heat exchange coil 5, so that the crystals fall off the heat exchange coil 5.

[0017] Specifically, if Figure 1As shown, the driving mechanism of this embodiment includes a motor 6, the motor 6 is fixedly mounted on the tank body 1, the output shaft of the motor 6 is fixedly connected to the vertical shaft 7, the output shaft of the motor 6 passes through the reserved hole on the tank body 1 and is connected to the vertical shaft 7, and the output shaft of the motor 6 is coaxially arranged with the vertical shaft 7. When the motor 6 is powered on, the motor 6 can drive the vertical shaft 7 to rotate, and the rotation direction of the vertical shaft 7 can be controlled by controlling the rotation direction of the motor 6.

[0018] Specifically, when the vertical shaft 7 drives the stirring rod 8 to rotate together, and the stirring rod 8 passes through the through groove 10 at the same time, the stirring rod 8 gives an extrusion force to the liquid, and the stirring rod 8 and the entire plate of the vertical plate 9 group will hinder the flow of the liquid, so that the rotation of the stirring rod 8 is subject to greater resistance. The vertical shaft 7 described in this embodiment is divided into multiple sections, and each section of the vertical shaft 7 has two stirring rods 8. The two adjacent sections of the vertical shaft 7 are connected together by a connecting structure. The connecting structure includes a groove 20. One section of the vertical shaft 7 is rotatably installed in the groove 20 of an adjacent section through a bearing. A first annular groove 21 is respectively provided in the groove 20, and a protrusion 22 is provided in the first annular groove 21. One side of the protrusion 22 is an inclined surface, and the other side is a vertical surface. When the first spring telescopic rod When 23 all rest on the inclined surfaces of the corresponding protrusions 22, the stirring rods 8 on the vertical shaft 7 are distributed in a spiral, the vertical surfaces of each protrusion 22 are coplanar, and the inclined surfaces are staggered. In this embodiment, the inclined surfaces on adjacent protrusions 22 are staggered by forty-five degrees around the axis of the vertical shaft 7. A first spring telescopic rod 23 is slidably provided in the first annular groove 21. The first spring telescopic rod 23 is fixedly installed on an adjacent section of the vertical shaft 7. The fixed end of the first spring telescopic rod 23 is fixedly installed on the vertical shaft 7, and the movable end of the first spring telescopic rod 23 is slidably installed in the first annular groove 21. The elastic force of the first spring telescopic rod 23 increases with the height of each section of the vertical shaft 7, that is, the elastic force of the lowest first spring telescopic rod 23 is the smallest, and the elastic force of the highest is the largest.Each section of the vertical shaft 7 is recorded as the first section, the second section, the third section, and the fourth section from top to bottom. When the motor 6 drives the vertical shaft 7 to rotate in the forward direction, the output shaft of the motor 6 first drives the first section to rotate, and the first spring telescopic rod 23 on the second section slides relative to the first annular groove 21 on the first section. When the inclined surface of the protrusion 22 on the first section contacts the first spring telescopic rod 23, the inclined surface drives the first spring telescopic rod 23 to rotate together, thereby driving the second section of the vertical shaft 7 to rotate together. The third and fourth sections of the vertical shaft 7 are the same as the above process principles. After the first spring telescopic rod 23 contacts the corresponding inclined surfaces, since the inclined surfaces on adjacent protrusions 22 are displaced by forty-five degrees around the axis of the vertical shaft 7, the stirring rods 8 on the two adjacent sections of the vertical shaft 7 are also displaced, so that the stirring rods 8 on the vertical shaft 7 are distributed in a spiral shape, so that the stirring rods 8 will not pass through the through groove 10 at the same time, and when the stirring rod 8 on one section passes through the through groove 10, the stirring rods on the remaining sections 8 will not pass through the through groove 10, so that the stirring rod 8 on each section passes through the corresponding through groove 10 in turn. Therefore, when the stirring rod 8 squeezes the liquid, the liquid can flow from other through grooves 10, thereby reducing the resistance of the stirring rod 8 when rotating; when the liquid precipitates crystals and settles at the bottom of the tank body 1, the fourth section of the vertical axis 7 will first contact the crystals, thereby being subjected to greater resistance until it cannot rotate. At this time, since the elastic force of the first spring telescopic rod 23 on the fourth section is the smallest, the first spring telescopic rod 23 on the fourth section will shorten first, and the inclined surface on the third section of the vertical axis 7 squeezes the first spring telescopic rod 23 on the fourth section, and the first spring telescopic rod 23 on the fourth section of the vertical axis 7 slides relative to the first annular groove 21 on the third section, and the first section to the third section of the vertical axis 7 continue to rotate. When the stirring rod 8 on the third section of the vertical axis 7 is blocked by the precipitated crystals and cannot rotate, the process principle is the same as that described in the fourth section, and the same is true for the second section of the vertical axis 7.

[0019] Further, such as Figure 1As shown, the second spring telescopic rod 30 is fixedly installed on the fourth section of the vertical axis 7 described in this embodiment, the fixed end of the second spring telescopic rod 30 is fixedly installed in the reserved groove at the bottom of the vertical axis 7, and a second annular groove 31 is provided on the vertical plate 9. The second spring telescopic rod 30 is slidably connected to the second annular groove 31, and the fixed end of the second spring telescopic rod 30 is fixedly connected to the inner wall of the reserved groove, and the movable end of the second spring telescopic rod 30 is slidably connected to the second annular groove 31. A section of the bottom surface of the second annular groove 31 is stepped, and the first spring telescopic rod 23 on the lowest section of the vertical axis 7 is coaxial with the second spring telescopic rod 30, and the elastic force of the second spring telescopic rod 30 is less than the elastic force of the first spring telescopic rod 23 on the lowest section of the vertical axis 7. When the motor 6 drives the vertical shaft 7 to rotate in the opposite direction, the output shaft of the motor 6 first drives the first section of the vertical shaft 7 to rotate, so that the first spring telescopic rod 23 on the second section of the vertical shaft 7 slides relative to the first annular groove 21 on the first section until the first spring telescopic rod 23 is blocked by the vertical surface of the protrusion 22 on the first section, and then the first section of the vertical shaft 7 drives the first spring telescopic rod 23 on the second section to rotate together, thereby driving the second section of the vertical shaft 7 to rotate together. The same principle as the above process will successively drive the third and fourth sections of the vertical shaft 7 to rotate together, and the fourth section of the vertical shaft 7 will drive the second spring telescopic rod 30 to rotate together, and the second spring telescopic rod 30 will slide in the second annular groove 31 until the second spring telescopic rod 30 is blocked by the step of the second annular groove 31, and the second spring telescopic rod 30 will drive the vertical plate 9 to rotate together, and the first spring telescopic rod 23 will rotate together. When the rod 23 is blocked by the corresponding vertical surface, the stirring rod 8 on the vertical axis 7 of the section where the first spring telescopic rod 23 is located is located in the corresponding through groove 10. When the second spring telescopic rod 30 is blocked, all the stirring rods 8 are located in the corresponding through groove 10, thereby forming a complete plate with the vertical plate 9; when the motor 6 drives the vertical axis 7 to rotate forward, the vertical axis 7 drives the second spring telescopic rod 30 to slide forward in the second annular groove 31. When the second spring telescopic rod 30 passes through the step of the second annular groove 31, it will not be blocked. The second spring telescopic rod 30 is extended under the action of elastic force and contacts the bottom surface of the step, and then slides along the bottom surface of the step. When the second spring telescopic rod 30 slides along the bottom surface of the step, the second spring telescopic rod 30 is gradually compressed, and then remains in a compressed state until it slides to the step again and extends, and the above process is repeated.

[0020] Furthermore, if Figure 1 As shown, the bottom of the tank body 1 in this embodiment is in an inverted cone shape. The bottom of the tank body 1 is in an inverted cone shape, so that the obtained crystals are more easily moved toward the ball valve 4, reducing the possibility of crystals accumulating at the bottom of the tank body 1.

[0021] Further, most of the domestic freezing and crystallization processes are to take the cooling agent to walk the crystallizer jacket and the internal coil to achieve the purpose of freezing potassium nitrate, that is, the refrigerant of the refrigerator first cools the cooling agent, and the cooling agent exchanges heat with potassium nitrate magnesium chloride solution, but the freezing and crystallization method performed by the cooling agent is a secondary freezing method, with large heat loss, low energy efficiency ratio, high energy consumption of system operation, and high operating cost of the system. The heat exchange coil 5 is connected with an external refrigeration system, and the refrigeration system includes a compressor, the input end of the compressor is connected to the outlet of the heat exchange coil 5, the output end of the compressor is connected to the input end of the outdoor condenser, the output end of the outdoor condenser is connected to the input end of the liquid reservoir, the output end of the liquid reservoir is connected to the input end of the throttle, the output end of the throttle is connected to the input end of the freezing pump, and the output end of the freezing pump is connected to the import of the heat exchange coil 5. The refrigerant after cooling in the device will directly enter the heat exchange coil 5, and then perform a heat exchange process with the solution in the tank body 1, eliminating the crystallization method of secondary freezing using a coolant, improving the efficiency of heat exchange, reducing heat loss, and thus reducing the energy consumption of system operation. The refrigerant gas generated by the direct heat exchange between the refrigerant and the solution is sucked away by the compressor, and the high-temperature and high-pressure gas generated by the compression enthalpy increase of the compressor is discharged to the outdoor condenser, and is condensed by the condenser to become a medium-temperature and high-pressure liquid that flows into the liquid reservoir. The medium-temperature and high-pressure refrigerant in the liquid reservoir becomes a low-temperature and low-pressure liquid after passing through the throttling device, and is again transported by the refrigeration pump to the heat exchange coil 5 to complete the next cycle, thereby achieving the ultimate purpose of cooling the potassium nitrate and magnesium chloride solution and causing the potassium nitrate to crystallize.

[0022] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A direct freezing crystallization device, comprising a tank body (1), a plurality of supporting legs (2) fixedly mounted on the tank body (1), a liquid inlet pipe (3) connected to and mounted on the tank body (1), a ball valve (4) connected to and mounted at the bottom of the tank body (1), a heat exchange coil (5) arranged in the tank body (1), an inlet end and an outlet end of the heat exchange coil (5) respectively extending to the outside of the tank body (1), characterized in that: A vertical shaft (7) and a driving mechanism for driving the vertical shaft (7) to rotate are provided in the tank body (1). A plurality of stirring rods (8) are fixedly installed on the vertical shaft (7). The vertical shaft (7) is rotatably connected to a vertical plate (9). A through groove (10) is provided on the vertical plate (9) corresponding to the stirring rod (8). The stirring rod (8) can seal the corresponding through groove (10) so that the vertical plate (9) and the vertical plate (9) form a complete plate. When the vertical shaft (7) rotates in the forward direction, it cannot drive the vertical plate (9) to rotate. When the vertical shaft (7) rotates in the reverse direction, it can drive the vertical plate (9) to rotate together. The driving mechanism comprises a motor (6). The motor (6) is fixedly installed on the tank body (1). The output shaft of the motor (6) is fixedly connected to the vertical shaft (7). The vertical shaft (7) is divided into a plurality of sections. Two adjacent sections of the vertical shaft (7) are connected by a connecting structure. The connecting structure comprises a groove (20), a section of the vertical shaft (7) is rotatably mounted in the groove (20) of an adjacent section through a bearing, a first annular groove (21) is respectively provided in the groove (20), a protrusion (22) is provided in the first annular groove (21), one side of the protrusion (22) is an inclined surface, and the other side is a vertical surface, when the first spring telescopic rods (23) are all against the corresponding inclined surfaces of the protrusions (22), the stirring rod (8) on the vertical shaft (7) is spirally distributed, the first spring telescopic rod (23) is slidably provided in the first annular groove (21), the first spring telescopic rod (23) is fixedly mounted on an adjacent section of the vertical shaft (7), and the elastic force of the first spring telescopic rod (23) increases with the height of each section of the vertical shaft (7).

2. A direct freezing crystallization device according to claim 1, characterized in that: A second spring telescopic rod (30) is fixedly mounted on the fourth section of the vertical shaft (7), a second annular groove (31) is provided on the vertical plate (9), the second spring telescopic rod (30) is slidably connected to the second annular groove (31), and a section of the bottom surface of the second annular groove (31) is stepped.

3. A direct freezing crystallization device according to claim 1, characterized in that: The bottom of the tank body (1) is in an inverted cone shape.

4. A direct freezing crystallization device according to claim 1, characterized in that: The heat exchange coil (5) is connected to an external refrigeration system, which includes a compressor, wherein the input end of the compressor is connected to the outlet of the heat exchange coil (5), the output end of the compressor is connected to the input end of the outdoor condenser, the output end of the outdoor condenser is connected to the input end of the liquid storage device, the output end of the liquid storage device is connected to the input end of the throttle, the output end of the throttle is connected to the input end of the refrigeration pump, and the output end of the refrigeration pump is connected to the inlet of the heat exchange coil (5).

Images