Rapid metaphosphoric acid cooling device and use method thereof

Abstract

The invention discloses a metaphosphoric acid rapid cooling device and a use method thereof. The metaphosphoric acid rapid cooling device comprises a cylindrical barrel; the barrel cover covers the top of the cylindrical barrel body; the feeding hole is formed in the center of the cylinder cover; the chassis is hermetically and rotatably connected with the bottom of the cylindrical barrel; the telescopic rod comprises a sleeve and a piston rod, and the sleeve is fixedly connected with the center of the chassis; the large bottom of the conical drainage piece is fixedly connected with the tail end of the piston rod, and the conical head part of the cylindrical drainage piece corresponds to the feeding hole; the annular cavity is distributed around the inner wall of the cylindrical barrel and surrounds the telescopic rod and the conical drainage piece, a first gap is reserved between the edge of the conical drainage piece and the inner wall of the annular cavity, and a second gap is reserved between the bottom of the annular cavity and the base plate; and the cooling medium is filled in the annular cavity. The metaphosphoric acid cooling device has the beneficial effects that metaphosphoric acid is cooled for multiple times, and the cooling rate is increased.

Description

Technical Field

[0001] This invention relates to the field of metaphosphoric acid preparation, and more particularly to a rapid cooling device for metaphosphoric acid and its usage method. Background Technology

[0002] Metaphosphoric acid is used as a chemical reagent, dehydrating agent, catalyst, and raw material for manufacturing plastic stabilizers. It is also used in the production of synthetic fibers and phosphites. The main industrial production methods are the high-temperature dehydration method of phosphoric acid and the phosphorus pentoxide reaction method. The principle of the high-temperature dehydration method of phosphoric acid is as follows: orthophosphoric acid (H3PO4) is heated to 250–300℃, and water molecules are removed through a condensation reaction to generate metaphosphoric acid polymer. The reaction time affects the degree of polymerization (n value), which needs to be precisely controlled to match the performance of the target product. Since the reaction temperature (250–300℃) is much higher than the melting point of metaphosphoric acid (73.6℃), the product is in a molten liquid state in the reactor. It needs to be rapidly cooled to prevent over-polymerization. After cooling, it forms a colorless glassy solid. If the molten metaphosphoric acid is cooled slowly, it will crystallize to form cyclic trimetaphosphate or tetrametaphosphate, affecting its functional properties (such as chelating ability and catalytic activity).

[0003] Current industrial-grade rapid cooling methods for metaphosphoric acid involve directly pouring the dehydrated molten metaphosphoric acid into a metal pan (such as an aluminum basin), where its high thermal conductivity allows for rapid heat dissipation. The melt solidifies into a glassy sheet within 60–120 seconds, suitable for small- to medium-scale production or products requiring high purity. However, variations in the thermal conductivity of the metal pans lead to inconsistent heat dissipation, potentially causing stress concentration within the glassy metaphosphoric acid and resulting in cracks or breakage, especially when the thickness is greater than 5 mm. This method relies on manual pouring of the melt and is only suitable for small- to medium-scale intermittent production (capacity < 1 ton / hour), making fully automated continuous operation impossible. Furthermore, at high melt temperatures, the aluminum basin surface is prone to oxidation and peeling, allowing iron impurities to enter the product and reduce purity.

[0004] Chinese invention patent publication number CN118935907A discloses a cooling structure for a phosphoric acid combustion tower. This patent is applicable to the combustion tower stage in the thermal phosphoric acid process, but not to the rapid cooling of phosphoric acid prepared by the high-temperature dehydration method of phosphoric acid. Summary of the Invention

[0005] The technical problem to be solved by this invention is that the existing rapid cooling method in the preparation of metaphosphoric acid by high temperature dehydration of phosphoric acid has many drawbacks. To address this, a rapid cooling device for metaphosphoric acid and its usage method are provided.

[0006] The technical solution of this invention is: a rapid cooling device for metaphosphoric acid, comprising: a cylindrical body; a cover, the cover being fitted onto the top of the cylindrical body; a feed inlet, the feed inlet being located at the center of the cover; a base, the base being rotatably and sealingly connected to the bottom of the cylindrical body; a telescopic rod, the telescopic rod comprising a sleeve and a piston rod, the sleeve being fixedly connected to the center of the base; a conical guide, the base of the conical guide being fixedly connected to the end of the piston rod, the conical head of the cylindrical guide corresponding to the feed inlet; an annular cavity, the annular cavity being distributed around the inner wall of the cylindrical body and surrounding the telescopic rod and the conical guide, such that the edge of the conical guide and the inner wall of the annular cavity maintain a first gap, and the bottom of the annular cavity and the base have a second gap; a cooling medium, the cooling medium filling the annular cavity; and a feed outlet, the feed outlet being located on the side wall of the cylindrical body and within the second gap.

[0007] The conical drainage component described in the above scheme is made of metal.

[0008] The conical drain element described in the above scheme is hollow inside and filled with cooling medium.

[0009] The annular cavity described in the above scheme is made of flexible material, and the outer wall of the cylindrical body is connected to the annular cavity by a liquid injection port.

[0010] The above-described solution includes a drive mechanism on the outside of the chassis to drive the chassis to rotate.

[0011] In the above scheme, a compression spring is adapted between the bottom of the piston rod and the sleeve.

[0012] The sleeve described in the above scheme is made of corrosion-resistant and heat-resistant material.

[0013] The method of using the rapid cooling device for metaphosphoric acid includes the following steps: injecting metaphosphoric acid into the feed inlet, the metaphosphoric acid impacting the conical guide, rotating the chassis, the chassis driving the conical guide to rotate, the metaphosphoric acid being dispersed into the first gap, the piston rod being pressed down, driving the conical guide to descend, during the descent the conical guide to continuously disperse the metaphosphoric acid into the first gap, the metaphosphoric acid finally falling into the chassis and accumulating.

[0014] The beneficial effects of this invention are that metaphosphoric acid first contacts the conical guide element for initial cooling. As the conical guide element rotates and descends, the metaphosphoric acid is evenly dispersed into the first gap and fully contacts the annular cavity for secondary cooling. Afterward, the metaphosphoric acid falls onto the chassis and is evenly dispersed on the chassis as the chassis rotates. The entire process can be carried out automatically or with manual assistance, which greatly improves the production capacity, avoids stress concentration inside the glassy metaphosphoric acid, and improves the cooling rate. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the rapid cooling device for metaphosphoric acid of the present invention; Figure 2 yes Figure 1 Schematic diagram of the connection between the mid-chassis, telescopic rod and conical drainage component; Figure 3 yes Figure 1 Schematic diagram of the annular cavity; Figure 4 yes Figure 1 Schematic diagram of the telescopic pole; In the diagram, 1 is a cylindrical body, 2 is a cylinder cover, 3 is a feed inlet, 4 is a chassis, 5 is a telescopic rod, 51 is a sleeve, 52 is a piston rod, 53 is a compression spring, 6 is a conical drain, 7 is an annular cavity, 8 is a material outlet, and 9 is a liquid injection port. Detailed Implementation

[0016] The technical solutions in 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 a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments implemented by those skilled in the art without creative effort are within the protection scope of the present invention.

[0017] like Figure 1-4 As shown, a rapid cooling device for metaphosphoric acid includes: a cylindrical body 1; a cover 2, which covers the top of the cylindrical body; a feed inlet 3, which is located at the center of the cover; a base 4, which is rotatably and sealingly connected to the bottom of the cylindrical body; a telescopic rod 5, which includes a sleeve 51 and a piston rod 52, the sleeve being fixedly connected to the center of the base; a conical guide 6, the base of which is fixedly connected to the end of the piston rod, and the conical head of which corresponds to the feed inlet; an annular cavity 7, which surrounds the inner wall of the cylindrical body and encloses the telescopic rod and the conical guide, such that the edge of the conical guide and the inner wall of the annular cavity maintain a first gap, and the bottom of the annular cavity and the base have a second gap; a cooling medium, which fills the annular cavity; and a feed outlet 8, which is located on the side wall of the cylindrical body and within the second gap.

[0018] In this invention, the cap can be detachably connected to the top of the cylindrical body. As an embodiment of this invention, the cap is threadedly connected to the cylindrical body. When needed, the cap can be removed to maintain the interior of the cylindrical body. The chassis is rotatably connected to the bottom of the cylindrical body, and the sealing components such as the cap sealing ring on the contact surface achieve dynamic sealing.

[0019] As an embodiment of the present invention, the telescopic rod can be driven without an external power source. For example, a compression spring 53 is adapted between the bottom of the piston rod and the sleeve. Under normal conditions, the cone head of the conical drainage component extends slightly beyond the top of the annular cavity. When metaphosphoric acid falls into contact with the conical drainage component, the compression spring is compressed, causing the conical drainage component to descend. When the metaphosphoric acid stops impacting the conical drainage component, the compression spring pushes the piston rod back to its initial position. Alternatively, an external power source, such as an air pump, can be used. The air pump introduces high-pressure gas into the sleeve through an air pipe, and the height of the piston rod can be adjusted by adjusting the air pump.

[0020] As an embodiment of the present invention, the annular cavity can be made of metal. In this case, the size of the first gap is fixed, and the phosphoric acid can be cooled down quickly when it comes into contact with the inner surface of the annular cavity.

[0021] As a preferred embodiment of the present invention, the material of the annular cavity can be a flexible material. The outer wall of the cylindrical body is connected to the annular cavity by a liquid injection port 9. The cooling medium is introduced into the annular cavity through the liquid injection port. The distance between the annular cavity and the conical guide, i.e., the size of the first gap, can be adjusted to accommodate different flow rates of metaphosphoric acid.

[0022] In one embodiment of the present invention, the conical drain element is made of metal, utilizing the high thermal conductivity of metal to rapidly dissipate heat. As a variation of this embodiment, the conical drain element is hollow and filled with a cooling medium, which can improve the heat dissipation effect.

[0023] In one embodiment of the invention, a handle is provided on the outer surface of the chassis, allowing manual rotation of the chassis. Alternatively, a driven gear can be provided around the bottom edge of the chassis, and a drive motor is provided outside the cylindrical body. A driving gear, meshing with the driven gear, is sleeved on the output shaft of the drive motor. Starting the drive motor causes the chassis to rotate.

[0024] Since the sleeve will come into contact with metaphosphoric acid, the sleeve is preferably made of corrosion-resistant and heat-resistant material, such as ceramic matrix composites, graphite, Hastelloy C276, etc. These materials can also be used in conical drainage parts and annular cavities.

[0025] The method of using the rapid cooling device for metaphosphoric acid includes the following steps: Metaphosphoric acid is injected into the feed inlet 3, impacting the conical guide 6 for initial cooling. The base 4 is rotated, causing the conical guide to rotate, dispersing the metaphosphoric acid into the first gap. The metaphosphoric acid flows along the inner wall of the annular cavity for secondary cooling. The piston rod 52 is pressurized and descends, causing the conical guide to descend. During the descent, the conical guide continuously disperses the metaphosphoric acid into the first gap, eventually causing it to accumulate in the base. The base can also be a hollow structure filled with a cooling medium, performing three cooling processes on the metaphosphoric acid, thus increasing the cooling rate to over 100℃ / min. The cooled metaphosphoric acid is then removed from the discharge port. Multiple discharge ports can be provided for easy removal, spaced apart on the cylindrical body. Baffles can be hinged to the discharge ports; these baffles are opened when material needs to be removed.

Claims

1. A rapid cooling device for metaphosphoric acid, characterized by: include: Cylindrical body (1); cylinder cover (2), the cylinder cover being closed on the top of the cylindrical body; feed inlet (3), the feed inlet being located at the center of the cylinder cover; The chassis (4) is sealed and rotatably connected to the bottom of the cylindrical body; the telescopic rod (5) includes a sleeve (51) and a piston rod (52), the sleeve being fixedly connected to the center of the chassis; the conical guide (6) has its large bottom fixedly connected to the end of the piston rod, and the conical head of the cylindrical guide corresponds to the feed inlet; the annular cavity (7) is distributed around the inner wall of the cylindrical body and surrounds the telescopic rod and the conical guide, such that the edge of the conical guide and the inner wall of the annular cavity retain a first gap, and the bottom of the annular cavity and the chassis have a second gap. Cooling medium, which is filled in the annular cavity; material inlet (8), which is opened on the side wall of the cylindrical body and located in the second gap.

2. The rapid cooling device for metaphosphoric acid as described in claim 1, characterized in that: The conical drainage component is made of metal.

3. The rapid cooling device for metaphosphoric acid as described in claim 1, characterized in that: The conical drain element is hollow and filled with a cooling medium.

4. The rapid cooling device for metaphosphoric acid as described in claim 1, characterized in that: The annular cavity is made of a flexible material, and there is a liquid injection port (9) connecting the outer wall of the cylindrical body and the annular cavity.

5. The rapid cooling device for metaphosphoric acid as described in claim 1, characterized in that: The chassis is equipped with a drive mechanism that drives the chassis to rotate.

6. The rapid cooling device for metaphosphoric acid as described in claim 1, characterized in that: A compression spring (10) is adapted between the bottom of the piston rod and the sleeve.

7. The rapid cooling device for metaphosphoric acid as described in claim 1, characterized in that: The sleeve is made of corrosion-resistant and heat-resistant material.

8. The method of using the rapid cooling device for metaphosphoric acid as described in any one of claims 1-7, characterized in that: Includes the following steps: Phosphoric acid is injected into the feed inlet (3), and the phosphoric acid impacts the conical guide (6). The chassis (4) is rotated, and the chassis drives the conical guide to rotate. The phosphoric acid is dispersed into the first gap. The piston rod (52) is pressed down, which drives the conical guide to descend. During the descent, the conical guide continues to disperse the phosphoric acid into the first gap. The phosphoric acid eventually falls into the chassis and accumulates.

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