Water circulation type DMC catalyst vacuum drying box
By combining water circulation heating and a vacuum environment, the problems of uneven heating and high energy consumption in DMC catalyst drying equipment have been solved, achieving a high-efficiency, safe, and convenient solution for low-temperature drying.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANDONG LONGHUA CHEM TECH CO LTD
- Filing Date
- 2026-01-30
- Publication Date
- 2026-04-21
AI Technical Summary
Existing DMC catalyst drying equipment suffers from problems such as uneven heating, high energy consumption, easy damage to heat-sensitive materials, and inconvenient cleaning and maintenance, making it particularly unsuitable for low-temperature drying requirements.
It adopts a combination of water circulation heating and vacuum environment, and heat is evenly transferred through serpentine coil. Combined with vacuum pump to reduce pressure, it achieves low temperature drying. It is equipped with thermometer and pressure gauge for real-time monitoring and adjustment.
It achieves uniform heating, low energy consumption, and safe and reliable low-temperature drying, significantly improving drying speed and equipment stability, and simplifying cleaning and maintenance.
Smart Images
Figure CN224151308U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of chemical equipment technology, specifically relating to a water-circulating DMC catalyst vacuum drying oven. Background Technology
[0002] Bimetallic cyanide complex catalysts (i.e., DMC catalysts) are catalysts generated by the reaction of water-soluble metal salts (such as zinc chloride ZnCl2) and cyano metal salts (such as potassium ferrocyanide K4[Fe(CN)6]). Their core application is to catalyze the ring-opening polymerization of epoxides. They have the advantage of extremely low dosage, only tens to hundreds of parts per million of the product mass, which is about one-thousandth of the dosage of KOH catalyst. They can produce polyether products with higher molecular weight and more uniform molecular weight distribution, resulting in superior product performance.
[0003] In the drying and molding stage of DMC catalyst production, drying is required under vacuum and low temperature (40-60℃) conditions to completely remove volatile substances. However, existing drying equipment on the market has many problems in practical applications, resulting in long drying time, poor drying effect, and the need for long-term operation, which increases energy consumption. Specifically, existing drying equipment mainly relies on air convection heating, but the insulation performance of the chamber is limited, making it prone to heat loss. It also relies on hot air circulation for heating, which can easily create temperature dead zones if poorly designed. Furthermore, overcrowding of items inside the oven or improper air vent design can lead to localized temperature differences, resulting in poor heating uniformity. In addition, uneven heating can cause some heat-sensitive materials to overheat, char, or denature, which is detrimental to heat-sensitive materials. In terms of energy consumption, the equipment consumes a lot of electricity during long-term operation or at high temperatures. Air has a low thermal conductivity and poor heat transfer efficiency, especially for thick or dense materials, where heat penetration is slow. It also relies on natural dehumidification through exhaust vents, resulting in excessively long drying cycles for high-humidity materials and a generally slow drying speed. Improper operation can also pose a risk of burns due to high temperatures. Traditional drying ovens typically operate at high temperatures (generally >50℃), making them unsuitable for materials requiring low-temperature drying, thus limiting their applicability. The interior of the equipment has many dead zones, making it difficult to thoroughly clean dust or residue after long-term use, resulting in inconvenient maintenance and cleaning. Utility Model Content
[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a water-circulating DMC catalyst vacuum drying oven, which adopts a combination of water circulation heating and vacuum environment, resulting in uniform heating, low energy consumption, safety and stability, fast drying speed, and suitability for the low-temperature drying requirements of DMC catalysts, and is also easy to clean and maintain.
[0005] This utility model is achieved using the following technical solution:
[0006] The aforementioned water-circulating DMC catalyst vacuum drying oven includes a main body of the drying oven. Inside the main body, multiple layers of continuously U-shaped serpentine coils are horizontally arranged, with a shelf above each layer of coils. A main water inlet pipe and a main water outlet pipe are vertically installed on both sides of the main body. The inlet end of each layer of coils is connected to the main water inlet pipe, and the outlet end is connected to the main water outlet pipe. The lower end of the main water inlet pipe and the upper end of the main water outlet pipe are respectively provided with an inlet and an outlet. The outlet is connected to a circulating pump, a mixer, and the inlet via pipes to form a water circulation loop. A steam pipe is connected to the mixer, and a water replenishment pipe is connected to the pipe between the mixer and the inlet. An exhaust port is located at the top of the main body of the drying oven, and this exhaust port is connected to a vacuum pump via a pipe to achieve vacuuming inside the main body of the drying oven.
[0007] The serpentine coils are fixed to the inner wall of the drying oven body by angle steel. Each layer of serpentine coils is arranged parallel to the length of the drying oven body and folds back and forth in the width direction through U-shaped bends, thus covering the entire interior horizontal plane of the drying oven body.
[0008] The water-circulating DMC catalyst vacuum drying oven also includes multiple thermometers, which are spaced apart between the serpentine coils along the height of the drying oven body, with the probes of the thermometers facing the internal drying area of the drying oven body.
[0009] The steam pipe and the water supply pipe are each equipped with a regulating valve.
[0010] The mixer is equipped with a sight glass on its outlet pipe.
[0011] Pressure gauges are installed on the top of the drying chamber body and on the outlet pipe of the circulating pump.
[0012] The drying oven body has a hinge structure on its side, and the drying oven body and the oven door are hinged together by the hinge structure. A sealing strip is embedded in the circumferential edge of the oven door.
[0013] The aforementioned water-circulating DMC catalyst vacuum drying oven uses low-temperature water circulation heating as its core heating method, combined with a vacuum environment to enhance the drying effect, thereby achieving efficient, uniform, and safe drying of the DMC catalyst. Its working principle is as follows:
[0014] The drying chamber's interior features a multi-layered serpentine coil system that covers the entire horizontal plane. Each shelf is positioned above its corresponding serpentine coil layer, employing a freely removable and movable assembly structure for easy material loading, unloading, and internal cleaning and maintenance. The serpentine coils evenly transfer the heat from the 50-60℃ circulating water to the DMC catalyst on each shelf, preventing localized temperature differences. A vacuum pump extracts air from the drying chamber through the exhaust port, reducing the internal pressure. Based on the principle that lower air pressure accelerates solvent evaporation, this shortens the removal cycle of volatile substances from the DMC catalyst. The circulating pump provides power to the water circulation loop, enabling continuous flow of circulating water between the main outlet pipe, the circulating pump, the mixer, the main inlet pipe, and the serpentine coil. The mixer introduces steam through a steam pipe to heat the circulating water, while simultaneously replenishing the circulating water loss through a makeup water pipe to ensure heating stability. The thermometer monitors the temperature at different heights within the chamber in real time, and the pressure gauges provide feedback on the vacuum level and circulating water system pressure. The regulating valve, sight glass, and chamber door with sealing strips respectively enable heating intensity adjustment, water volume observation, and chamber sealing, ensuring a precise, safe, and controllable drying process.
[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0016] (1) The water-circulating DMC catalyst vacuum drying oven described in this utility model adopts a water-circulating heating method and uses serpentine coils evenly distributed inside the drying oven body. Combined with the vacuum environment, it effectively reduces heat loss, improves heating uniformity, avoids temperature dead zones and local temperature difference problems, and reduces the energy consumption of electricity and steam. The equipment has a low failure rate and stronger stability during operation.
[0017] (2) The water-circulating DMC catalyst vacuum drying oven described in this utility model adopts low-temperature water circulation heating as a whole, there is no high-temperature heat source, and no motor is installed inside the main body of the drying oven. The use process is safe and reliable, avoiding the risk of burns caused by high temperature, and eliminating related electrical safety hazards. At the same time, the internal structure of the drying oven is simple and easy to clean, reducing the difficulty of maintenance and cleaning.
[0018] (3) The water-circulating DMC catalyst vacuum drying oven described in this utility model reduces the pressure inside the drying oven body by using a vacuum pump, which accelerates the evaporation of solvent in the DMC catalyst and significantly improves the drying speed. At the same time, the low-temperature water circulation design is adapted to the low-temperature drying requirements of DMC catalyst at 40-60℃, breaking through the limitations of traditional ovens on the application of materials dried at low temperatures. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the overall structure of the water-circulating DMC catalyst vacuum drying oven described in this utility model;
[0020] Figure 2This is a front view of the interior of the drying oven body described in this utility model;
[0021] Figure 3 This is a left view of the interior of the drying oven body of this utility model;
[0022] Figure 4 This is a schematic diagram of the serpentine coil structure described in this utility model;
[0023] Figure 5 This is a schematic diagram of the structure of the box door described in this utility model;
[0024] In the diagram: 1. Drying oven body; 2. Snake coil; 3. Shelf; 4. Main water inlet pipe; 5. Main water outlet pipe; 6. Water inlet; 7. Water outlet; 8. Circulation pump; 9. Mixer; 10. Steam pipe; 11. Water supply pipe; 12. Exhaust port; 13. Vacuum pump; 14. Angle steel; 15. Thermometer; 16. Regulating valve; 17. Sight glass; 18. Pressure gauge; 19. Folding structure; 20. Sealing strip. Detailed Implementation
[0025] To make the objectives and technical solutions of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.
[0026] Example 1
[0027] like Figure 1-5 As shown, the water-circulating DMC catalyst vacuum drying oven includes a drying oven body 1. Inside the drying oven body 1, twelve layers of continuous U-shaped serpentine coils 2 are horizontally arranged, with a shelf 3 correspondingly arranged above each layer of serpentine coils 2. A main water inlet pipe 4 and a main water outlet pipe 5 are vertically arranged on both sides of the drying oven body 1. The water inlet end of each layer of serpentine coils 2 is connected to the main water inlet pipe 4, and the water outlet end is connected to the main water outlet pipe 5. The lower end of the main water inlet pipe 4 and the upper end of the main water outlet pipe 5 are respectively provided with a water inlet 6 and a water outlet 7. The water outlet 7 is connected to a circulating pump 8, a mixer 9, and the water inlet 6 in sequence through a pipe to form a water circulation loop. A steam pipe 10 is connected to the mixer 9, and a water replenishment pipe 11 is connected to the pipe between the mixer 9 and the water inlet 6. An exhaust port 12 is provided on the top of the drying oven body 1, and the exhaust port 12 is connected to a vacuum pump 13 through a pipe.
[0028] The serpentine coil 2 is fixed to the inner wall of the drying oven body 1 by angle steel 14. Each layer of serpentine coil 2 is arranged in parallel along the length of the drying oven body 1 and is folded back and forth in the width direction by U-shaped bends, so as to cover the entire interior horizontal plane of the drying oven body 1.
[0029] The water-circulating DMC catalyst vacuum drying oven also includes three thermometers 15, which are spaced apart between the serpentine coils 2 along the height of the drying oven body 1, with the probes of the thermometers 15 facing the internal drying area of the drying oven body 1.
[0030] The steam pipe 10 and the water supply pipe 11 are respectively equipped with regulating valves 16.
[0031] The mixer 9 is provided with a sight glass 17 on its outlet pipe.
[0032] Pressure gauges 18 are installed on the top of the drying chamber body 1 and on the outlet pipe of the circulating pump 8, respectively.
[0033] The drying oven body 1 has a hinge structure 19 on its left side. The drying oven body 1 and the oven door are hinged together by the hinge structure 19. A sealing strip 20 is embedded in the circumferential edge of the oven door.
[0034] The specific steps for doing this are as follows:
[0035] First, evenly spread the DMC catalyst to be dried on each layer of shelf 3. Then, place each layer of freely removable shelf 3 above the corresponding layer of serpentine coil 2 inside the drying chamber body 1. Close the chamber door, using the sealing strip 20 embedded in the circumferential edge of the door to ensure a good seal inside the drying chamber body 1. Start the circulation pump 8. Circulating water enters the water circulation loop under the drive of the circulation pump 8, flows out from the outlet 7 of the main outlet pipe 5, and then flows through the circulation pump 8 into the mixer 9. At this time, open the regulating valve 16 on the steam pipe 10, and steam is introduced into the mixer 9 to fully mix with the circulating water and heat the circulating water. The heating intensity is controlled by adjusting the regulating valve 16 on the steam pipe 10 to stabilize the circulating water temperature at 55±5℃. The operator observes the circulating water volume through the sight glass 17 on the outlet pipe of the mixer 9. If the water volume is insufficient, the regulating valve 16 on the water replenishment pipe 11 can be opened to add an appropriate amount of water to the water circulation loop until the water volume meets the operating requirements.
[0036] After the circulating water is heated by the mixer 9 and replenished to the appropriate amount, it flows into the main water inlet pipe 4 through the inlet 6 of the main water inlet pipe 4, and then flows into the serpentine coils 2 connected to the main water inlet pipes 4 on both sides of the drying chamber body 1. The serpentine coils 2 are fixed to the inner wall of the drying chamber body 1 by angle steel 14, and are arranged parallel along the length direction of the drying chamber body 1, folding back and forth in the width direction and covering the internal horizontal plane. When the circulating water flows in the serpentine coils 2, it evenly transfers heat to the DMC catalyst on the upper shelf 3. Simultaneously, the vacuum pump 13 is started, and air is drawn from the drying chamber through the exhaust port 12 at the top of the drying chamber body 1, creating a vacuum environment inside the drying chamber body 1 and accelerating the evaporation rate of the solvent in the DMC catalyst. During the drying process, three thermometers 15 are spaced apart between the serpentine coils 2 along the height direction of the drying chamber body 1. Their probes monitor the temperature of different drying areas at different heights in the chamber in real time to ensure that the temperature uniformity meets the process requirements. The pressure gauge 18 at the top of the drying chamber body 1 displays the vacuum pressure inside the chamber in real time, and the pressure gauge 18 on the outlet pipe of the circulating pump 8 monitors the operating pressure in the water circulation loop in real time. The operator can adjust the operating status of the vacuum pump 13 and the operating parameters of the circulating pump 8 in a timely manner according to the readings of the two pressure gauges 18 to ensure stable operation of the equipment.
[0037] After the drying process is completed, first turn off the vacuum pump 13 and the regulating valve 16 on the steam pipe 10. After the pressure inside the drying chamber 1 returns to normal pressure and the temperature drops to room temperature, turn off the circulation pump 8, open the chamber door, and remove each layer of the placement plate 3 from above the corresponding layer of serpentine coil 2. Then collect the dried DMC catalyst to complete the entire drying process.
[0038] If you need to clean the inside of the equipment, you can expose the serpentine coil 2 and the interior space of the drying chamber body 1 by removing the shelf 3, so that you can thoroughly clean the accumulated dust or residue.
Claims
1. A water circulation type DMC catalyst vacuum drying oven, characterized by, The drying chamber includes a main body (1), inside which are horizontally arranged multiple layers of continuous U-shaped serpentine coils (2), with a shelf (3) arranged above each layer of serpentine coils (2); a main water inlet pipe (4) and a main water outlet pipe (5) are respectively erected on both sides of the main body (1). The water inlet end of each layer of serpentine coils (2) is connected to the main water inlet pipe (4), and the water outlet end is connected to the main water outlet pipe (5). The lower end of the main water inlet pipe (4) and the upper end of the main water outlet pipe (5) are connected to the main water outlet pipe (5). The end is provided with an inlet (6) and an outlet (7); the outlet (7) is connected to the circulating pump (8), the mixer (9) and the inlet (6) in sequence through a pipe to form a water circulation loop; the mixer (9) is connected to a steam pipe (10), and the pipe between the mixer (9) and the inlet (6) is connected to a water replenishment pipe (11); the top of the drying box body (1) is provided with an exhaust port (12), and the exhaust port (12) is connected to a vacuum pump (13) through a pipe.
2. The water circulation type DMC catalyst vacuum drying oven according to claim 1, characterized in that, The serpentine coil (2) is fixed to the inner wall of the drying oven body (1) by angle steel (14). Each layer of serpentine coil (2) is arranged in parallel along the length of the drying oven body (1) and folds back and forth in the width direction through U-shaped bends, thus covering the entire interior horizontal plane of the drying oven body (1).
3. The water-circulating DMC catalyst vacuum drying oven according to claim 1, characterized in that, It also includes multiple thermometers (15), which are spaced apart between the serpentine coils (2) along the height direction of the drying chamber body (1), and the probe end of the thermometers (15) faces the internal drying area of the drying chamber body (1).
4. The water circulation type DMC catalyst vacuum drying oven according to claim 1, characterized in that, The steam pipe (10) and the water supply pipe (11) are respectively equipped with regulating valves (16).
5. The water-circulating DMC catalyst vacuum drying oven according to claim 1, characterized in that, The mixer (9) is provided with a sight glass (17) on its outlet pipe.
6. The water-circulating DMC catalyst vacuum drying oven according to claim 1, characterized in that, Pressure gauges (18) are installed on the top of the main body (1) of the drying chamber and on the outlet pipe of the circulating pump (8).
7. The water-circulating DMC catalyst vacuum drying oven according to claim 1, characterized in that, The drying oven body (1) is provided with a hinge structure (19) on the side. The drying oven body (1) and the oven door are hinged through the hinge structure (19). A sealing strip (20) is embedded in the circumferential edge of the oven door.