Laboratory drying system containing crystal water compound and control method thereof

Abstract

The invention belongs to the technical field of laboratory equipment, and particularly relates to a laboratory drying system containing crystal water compounds and a control method thereof.The laboratory drying system comprises a miniature hot blast stove, a fluidized bed, a cyclone dust collector and a bag-type dust collector, and a distribution plate net is arranged in the fluidized bed. The other side of the supporting seat is connected with a foundation through a hinge; the two vibration motors are arranged side by side in the material flowing direction, the rotation directions are opposite, the vibration directions of the vibration motors are perpendicular, and the angle is 90 + / -0.5 degrees. The invention has the following advantages: (1) the distribution plate net vertically vibrates at an angle of 90 + / -0.5 degrees, the material uniformity is improved by 40%, and the hot air penetration rate is increased by 50%; (2) the fluidized bed is subjected to closed-loop control at an inclination angle of 3 degrees, so that zero-residue discharge is realized; and (3) the temperature control precision is + / -2 DEG C through the micro hot blast stove and PID control, and compared with the control precision of + / -10 DEG C of traditional drying equipment, remarkable progress is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of powder material drying, and in particular relates to a laboratory drying system for a compound containing crystalline water and a control method thereof. Background Art

[0002] The primary function of a laboratory dryer is to achieve rapid dehydration, moisture-proof storage, or stability testing of samples by controlling the humidity and temperature environment. It is primarily suitable for the efficient drying of inorganic salt crystals, heat-resistant powders, nanopowders, and pharmaceutical intermediates. Laboratory dryers are suitable for heat-sensitive materials (such as biological agents) or samples requiring precise humidity control. Moisture-proof storage: A sealed environment combined with a desiccant (such as silica gel, CaCl2) allows for long-term storage of dried samples. Stability testing: In fields such as pharmaceuticals, staged vacuum drying can preserve protein activity (for example, the activity retention rate of lyophilized powder injections exceeds 95%).

[0003] The main types of laboratory dryers are: 1) Vacuum drying oven, which is suitable for heat-sensitive, easily decomposable, easily oxidizable substances and items with complex components. It accelerates drying and reduces oxidation risks through a vacuum environment. It is commonly used in biochemistry, medicine and other fields. 2) Blast drying oven, which achieves uniform heating through forced convection air circulation. It is suitable for scenarios that require rapid drying (such as electronic components, chemical materials, etc.) and can adjust the temperature range to a wider range. 3) Fluidized bed dryer, which uses fluidization technology to dry wet materials. Bulk granular solid materials are added to the fluidized bed dryer by a feeder. The filtered clean air is heated and sent to the bottom of the fluidized bed by a blower. It contacts the solid material through the distribution plate mesh, forming a fluidized state to achieve gas-solid heat and mass exchange.

[0004] The common shortcomings of traditional fluidized bed dryers are: 1) Insufficient miniaturization: There is a lack of miniaturized and temperature-controlled vibrating fluidized bed equipment, and industrial-grade fluidized beds cannot be used in limited laboratory spaces (usually <5m 2 ) deployment, which cannot meet the needs of small-scale trial production in the laboratory; 2) Low discharge efficiency: Traditional equipment requires manual cleaning, and the material residue rate is >8%; 3) Temperature control accuracy defects: Existing equipment is generally below 400°C, and cannot achieve the precise dehydration requirements of the 500-600°C medium temperature range; 4) The material is prone to stratification and compaction during the drying process, and the discharge residue rate is as high as more than 8%; 5) The vacuum drying process is time-consuming (usually 1-4 hours), energy-intensive, and cannot be produced continuously; 6) Existing technologies cannot simultaneously control the deep removal of crystallization water and surface water. The technical indicators of existing laboratory drying equipment are compared in Table 1:

[0005] Table 1

[0006] Device Type Temperature range Residual rate Temperature control accuracy Laboratory compatibility drum dryer 100-300℃ 10-15％ ±15℃ <![CDATA[Difference (occupied area > 10m 2 )]]> vacuum dryer 50-200℃ 5-8％ ±5℃ Medium (cannot continue) Traditional fluidized bed dryer ≤400℃ 8-12％ ±10℃ Poor (no miniaturization) Summary of the Invention

[0007] The purpose of the present invention is to provide a laboratory drying system and control method for compounds containing hydrated crystals, which overcomes the shortcomings of the prior art and can achieve precise temperature control with an accuracy of ±2°C in the medium temperature range of 500-600°C, and reduce the discharge residual rate to 0%; the system occupies an area of ​​≤5m 2 The power consumption is less than 0.25kw. It can remove surface water and crystal water simultaneously within 20-40 minutes, supports continuous / intermittent dual-mode production, has closed drying and self-draining functions, and is suitable for deep dehydration of inorganic salt crystals, heat-resistant powders, nanopowders and pharmaceutical intermediates in the laboratory. After drying, the material is discharged with zero residue.

[0008] To achieve the above object, the present invention is implemented through the following technical solutions:

[0009] One of the technical solutions: A laboratory drying system containing crystalline water compounds, including a micro hot air furnace, a fluidized bed, a cyclone dust collector and a bag dust collector, wherein a distribution plate net is provided in the fluidized bed, and the fluidized bed is a top-bottom combined structure, including an air collecting hood and a lower box body, along the material flow direction, an air collecting hood is provided with an inlet on one side, and a lower box body is provided with a discharge port on the other side, and a discharge valve is provided at the discharge port; the fluidized bed is connected to the support seat through a vibration isolation spring; a plurality of air collecting pipes are provided on the top of the air collecting hood; a vibration motor is connected to the bottom of the lower box body; a distribution plate net is provided horizontally in the lower box body, and the distribution plate net is provided horizontally in the lower box body. The periphery of the net is in close contact with the lower box, and a plurality of air inlets are provided on the side wall of the lower box below the distribution plate net, which are connected to a micro hot air furnace through a pipe; the fluidized bed is controlled by a triple coordinated mechanism: closed temperature control with timed discharge, and temperature fluctuation is stable at ±2°C; the bottom of one side of the support seat is connected to the lifting mechanism, and the other side of the support seat is hinged to the foundation to achieve gravity-vibration coupled discharge at a micro-inclination angle of 3°±0.2°; there are two vibration motors, which are arranged side by side along the direction of material flow and rotate in opposite directions. The vibration direction of the vibration motor is perpendicular to the distribution plate net, and the angle is 90°±0.5°.

[0010] Furthermore, the fluidized bed is a closed stainless steel box; the pore size of the distribution plate mesh is 50nm-2mm.

[0011] Furthermore, the lifting mechanism is an electric push rod or a cylinder with a maximum stroke of 100 mm and an accuracy of ±0.1 mm.

[0012] Furthermore, the support seat is provided with an inclination sensor with a maximum range of 10° and an accuracy of ±0.1°.

[0013] Furthermore, the power of the micro hot air furnace is 5-10kW, and the air supply volume is 5-8m 3 / min.

[0014] Furthermore, the size of the fluidized bed is 200 mm×1100 mm×150 mm; the power of the vibration motor is 0.03-0.12 kW, and the total power is <0.25 kW.

[0015] Furthermore, the overall area occupied by the system is less than 5m 2 , adapted to 220V standard laboratory power supply, meeting the laboratory environment.

[0016] Furthermore, the micro hot air furnace is provided with a PID temperature control module, which can be set within the range of 500-600°C with an accuracy of ±2°C.

[0017] Technical Solution 2: A control method for a laboratory drying system containing hydrated compounds. The specific operating steps are as follows: 1) Start vibration feeding: Start the vibration motor under the fluidized bed, maintain the vibration direction at 90°±0.5°, and introduce 500-600℃ hot air into the fluidized bed with a flow rate of 0.1-0.8m 3 / s, add a compound containing hydrated crystals into the closed fluidized bed; 2) Medium-temperature fluidization: maintain a vibration frequency of 11-30 Hz, and dry regularly for 20-40 minutes until the surface water + hydrated crystal content is ≤0.5%; 3) Angle discharge: maintain vibration and hot air operation, lift the side of the feed port to form a 3°±0.2° inclination of the distribution plate mesh, and the material is discharged autonomously from the discharge port until the residual rate is <0.1%, at which point the discharge is completed.

[0018] Furthermore, the vibration direction of the vibration motor is adjusted by the angle of the eccentric block, which is checked and recorded before the system works.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) The present invention achieves the following: ① The distribution plate mesh vibrates vertically at an angle of 90°±0.5°, achieving uniform material distribution, improving uniformity by 40% and increasing hot air penetration by 50%, solving the problem of particle compaction; ② The fluidized bed is closed-loop controlled at an inclination angle of 3° to avoid compaction and stratification, achieving zero-residue discharge (residue rate <0.1%), compared to >8% in traditional equipment; ③ The micro hot air furnace + PID control achieves a temperature control accuracy of ±2°C, a significant improvement over the ±10°C control accuracy of traditional drying equipment.

[0021] 2) Better meet the application needs of the laboratory, including: ① Compact structure: covers an area of ​​5m 2(including piping); ② Dual power adapter: 220V / 380V automatic switching, stronger environmental adaptability, unit energy consumption of 0.8kW·h / kg, a 68% reduction; ③ Intelligent control: Touch screen setting of temperature / frequency / inclination parameters, combined with vibration fluidization, shortens drying time to 1 / 6 of traditional processes, drying time is shortened to 20-40 minutes, and operation is more convenient; ④ The discharge process achieves zero splash and zero residue (residue rate <0.1%), and the dehydration rate of anhydrous magnesium sulfate reaches 99.7% (water content 66.4% → 0.3%);

[0022] 3) This equipment breaks through the technical bottleneck of high-temperature deep dehydration of laboratory powders and is particularly suitable for the efficient drying of inorganic salt crystals, heat-resistant powders, nanopowders, and pharmaceutical intermediates. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of an embodiment of the present invention;

[0024] Figure 2 yes Figure 1 A top view of

[0025] Figure 3 Schematic diagram of the fluidized bed structure in an embodiment of the present invention, showing vertical vibration;

[0026] Figure 4 Schematic diagram of 3° tilting discharging with electric push rod-hinge linkage in an embodiment of the present invention;

[0027] Figure 5 This is a hot blast stove control flow chart in an embodiment of the present invention;

[0028] In the figure: 1-feeding port, 2-gas collecting hood, 3-gas collecting pipe, 4-fluidized bed, 5-lifting mechanism, 6-vibration motor, 7-air inlet, 8-distribution plate net, 9-support seat, 10-vibration isolation spring, 11-discharge port, 12-discharge valve, 13-lower box, 14-foundation, 15-micro hot air furnace, 16-cyclone separator, 17-bag dust collector, 18-hinge. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific 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 any creative work.

[0031] The components of the embodiments of the present invention generally described and shown in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention.

[0032] The following is an example of dehydration of magnesium sulfate heptahydrate. The magnesium sulfate heptahydrate crystals are needle-shaped and have an initial water content of: 15% surface water + 51.4% crystal water = 66.4%.

[0033] See Figure 1-4 , is a structural schematic diagram of an embodiment of a laboratory drying system containing crystalline water compounds of the present invention, comprising a fluidized bed 4 and a distribution plate net 8. The fluidized bed 4 is an upper and lower combined structure, comprising an air collecting hood 2 and a lower box body 13. Along the material flow direction, one side of the air collecting hood 2 is provided with an inlet 1 facing upward, and the other side of the lower box body 13 is provided with a discharge port 11 facing downward, and a discharge valve 12 is provided at the discharge port 11; the fluidized bed 4 is connected to the support seat 9 through a vibration isolation spring 10; a plurality of air collecting pipes 3 are provided on the top of the air collecting hood 2; a vibration motor 6 is connected to the bottom of the lower box body 13; a distribution plate net 8 is horizontally arranged in the lower box body 13, and the distribution plate net 8 is made of 321 stainless steel plate processed by laser microporous processing. The periphery of the distribution plate net 8 is in close contact with the lower box body 13, which prevents material leakage and improves the air permeability by 35%.

[0034] The side wall of the lower box 13 below the distribution plate net 8 is provided with multiple air inlets 7, and the air inlets 7 are connected to the foundation 14 through pipes; the bottom of one side of the support seat 9 is connected to the lifting mechanism 5, and the other side of the support seat 9 is connected to the foundation 14 with a hinge 18; the support seat 9 is provided with an inclination sensor with a maximum range of 10° and an accuracy of ±0.1°. The electric push rod is controlled to realize closed-loop control of the angle. When discharging, the inclination angle of the distribution plate net 8 is stably maintained at 3°±0.2°.

[0035] In the embodiment of the present invention, there are two vibration motors 6, symmetrical dual vibration motors (total power <0.25kW), the single-machine power of the vibration motor 6 is 0.03-0.12kW, and the total power is <0.25kW, which meets the laboratory environment. The two vibration motors 6 are symmetrically arranged side by side along the material flow direction, with opposite rotation directions. The vibration direction of the vibration motor 6 is vertical, and the vibration angle is 90°±0.5°, which eliminates the material stratification phenomenon. The vibration direction of the vibration motor 6 is adjusted by the eccentric block angle. The symmetrical setting of the dual motors can eliminate the uneven problem caused by the uneven loading of the material, and improve the vibration uniformity by 40%. The discharge valve 12 is linked to the vibration motor 6 for control to keep the vibration motor 6 running during discharge.

[0036] The lifting mechanism 5 is an electric push rod with a maximum stroke of 100mm and an accuracy of ±0.1mm. The power of the micro hot air furnace 15 is 5-10kW and the air supply volume is 5-8m 3 / min, suitable for 220V / 380V power supply. The hot air pipeline is 316L stainless steel pipe, with ceramic fiber as insulation layer, so that the heat loss of the pipeline is less than 3% under 600℃ working conditions. The micro hot air furnace 15 is equipped with a PID temperature control module, which is adjustable within the range of 500-600℃ with an accuracy of ±2℃. Figure 5 Control flow chart of the medium hot air furnace. After the system is started, the drying temperature is set to 500-600℃. The PID temperature control module cyclically detects the temperature inside the box and feeds back to the control unit. The control unit sends a processing signal to drive the heating element or adjust the fan speed to adjust the heating power and air volume so that the hot air output of the micro hot air furnace 15 meets the requirements.

[0037] The air collecting pipe 3 is connected to the cyclone separator 16, and the exhaust port of the cyclone separator 16 is connected to the bag dust collector 17. The bag dust collector 17 is a mechanical float type condensed water recovery device. A relevant air valve is provided at the bottom of the cyclone separator 16.

[0038] The present invention provides a control method for a laboratory drying system containing a hydrated compound, and the specific operating steps are as follows: 1) Start vibration feeding: start the vibration motor under the fluidized bed, maintain the vibration direction at 90°±0.5°, and introduce 500-600°C hot air into the fluidized bed with a flow rate of 0.1-0.8m 3 / s, add a compound containing hydrated crystals into the closed fluidized bed; 2) Medium-temperature fluidization: maintain a vibration frequency of 11-30 Hz, and dry regularly for 20-40 minutes until the surface water + hydrated crystal content is ≤0.5%; 3) Angle discharge: maintain vibration and hot air operation, lift the side of the feed port to form a 3°±0.2° inclination of the distribution plate mesh, and the material is discharged autonomously from the discharge port until the residual rate is <0.1%, at which point the discharge is completed.

[0039] When the embodiment of the present invention is working, taking nano-alumina containing crystal water as an example, the wet material (water content 66.4%) is added from the fluidized bed feed port, and the feed rate is: 2kg / 0.5h; the vibration motor is started, the vibration frequency is 20Hz, and 560℃±1.5℃ hot air (1m / s) is introduced, and the drying is continued for 25min. The material is automatically discharged once. During the discharge, the electric push rod is lifted so that the distribution plate mesh 8 reaches an inclination angle of 3°, and the dried material is discharged automatically. The dust-containing moisture generated during the drying process is separated and collected by the gas collecting hood, cyclone separator and bag dust collector. The result data of the embodiment: ① Output: anhydrous magnesium sulfate, ② Final moisture content: 0.3%, ③ Product purity: ≥99.3%, ④ Particle size: ≤1mm white powder, ⑤ Discharge residue: 0%.

[0040] The process parameters in the embodiment are set as shown in Table 1 below.

[0041] Parameter items Numerical range Preferred value Hot air temperature 500-600℃ 560℃ Vibration frequency 11-30Hz 20Hz Drying time 20-40 minutes 25min Hot air flow rate 0.5-1.2m / s 1m / s Discharge angle 3°±0.2° 3°

[0042] In the embodiment, the fluidized bed 4 is a closed stainless steel box with dimensions of 200 mm × 1100 mm × 150 mm, covering an area of ​​< 1.5 m 2 ; The aperture of the distribution plate mesh 8 is 1.5 mm. The laboratory drying system of the present invention has a more compact structure, is suitable for the narrow environment in the laboratory, is powered by a 220V power supply, and has stronger adaptability to the environment; the control system of the embodiment is equipped with a touch screen, which can set parameters such as temperature / frequency / inclination, making the operation more convenient and the intelligence more convenient. After drying, the moisture content of the wet material dropped from 66.4% to 0.3%. There was no temperature drift during continuous operation for 8 hours, and the particle agglomeration rate was <3%. The system of the present invention is also suitable for the efficient drying of inorganic salt crystals, heat-resistant powders, nanopowders, and pharmaceutical intermediates in the laboratory.

[0043] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A laboratory drying system containing crystalline water compounds, comprising a micro hot air furnace, a fluidized bed, a cyclone dust collector and a bag dust collector, wherein a distribution plate net is provided in the fluidized bed, and the fluidized bed is a combined structure of upper and lower parts, comprising an air collecting hood and a lower box body, along the direction of material flow, an air collecting hood is provided with an inlet on one side facing upward, and a discharge port is provided on the other side of the lower box body, and a discharge valve is provided at the discharge port; the fluidized bed is connected to the support seat through a vibration isolation spring; a plurality of air collecting pipes are provided on the top of the air collecting hood; a vibration motor is connected to the bottom of the lower box body; a distribution plate net is horizontally provided in the lower box body, the periphery of the distribution plate net is in close contact with the lower box body, a plurality of air inlets are provided on the side wall of the lower box body below the distribution plate net, and the air inlet is connected to the micro hot air furnace through a pipeline; it is characterized in that The fluidized bed is controlled by a triple coordinated mechanism: closed temperature control with timed discharge, and temperature fluctuations are stabilized at ±2°C; the bottom of one side of the support seat is connected to a lifting mechanism, and the other side of the support seat is hinged to the foundation to achieve gravity-vibration coupled discharge at a micro-inclination angle of 3°±0.2°; there are two vibration motors, which are arranged side by side along the direction of material flow and rotate in opposite directions. The vibration direction of the vibration motor is perpendicular to the distribution plate mesh, with an angle of 90°±0.5°.

2. A laboratory drying system containing crystal water compounds according to claim 1, characterized in that, The fluidized bed is a sealed stainless steel box; the aperture of the distribution plate mesh is formed by laser micro-hole processing, and the distribution plate mesh is convenient and fast to replace.

3. A laboratory drying system containing crystal water compounds according to claim 1, characterized in that, The lifting mechanism is an electric push rod or oil cylinder with a maximum stroke of 100mm and an accuracy of ±0.1mm.

4. A laboratory drying system containing crystal water compounds according to claim 1, characterized in that, The support seat is provided with an inclination sensor with a maximum range of 10° and an accuracy of ±0.1°.

5. A laboratory drying system containing hydrated compounds according to claim 1, characterized in that, The power of the micro hot air furnace is 5-10kW, and the air supply volume is 5-8m 3 / min.

6. A laboratory drying system containing hydrated compounds according to claim 1, characterized in that, The size of the fluidized bed is 200 mm×1100 mm×150 mm; the power of the vibration motor is 0.03-0.12 kW, and the total power is less than 0.25 kW.

7. A laboratory drying system containing crystal water compounds according to claim 7, characterized in that, The overall area occupied by the system is less than 5m 2 , adapted to 220V standard laboratory power supply, meeting the laboratory environment.

8. A laboratory drying system containing hydrated compounds according to claim 1, characterized in that, The micro hot air furnace is provided with a PID temperature control module, which can be set within the range of 500-600°C with an accuracy of ±2°C.

9. The control method for a laboratory drying system containing a hydrated crystal compound according to any one of claims 1 to 8, wherein: The specific operation steps are as follows: 1) Start vibration feeding: Start the vibration motor under the fluidized bed, maintain the vibration direction at 90°±0.5°, and introduce 500-600℃ hot air into the fluidized bed with a flow rate of 0.1-0.8m 3 / s, add a compound containing hydrated crystals into the closed fluidized bed; 2) Medium-temperature fluidization: maintain a vibration frequency of 11-30 Hz, and dry regularly for 20-40 minutes until the surface water + hydrated crystal content is ≤0.5%; 3) Angle discharge: maintain vibration and hot air operation, lift the side of the feed port to form a 3°±0.2° inclination of the distribution plate mesh, and the material is discharged autonomously from the discharge port until the residual rate is <0.1%, at which point the discharge is completed.

10. The control method of a laboratory drying system containing a hydrated crystal compound according to claim 9, characterized in that: The vibration direction of the vibration motor is adjusted by the angle of the eccentric block, which is checked and recorded before the system works.

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