A three-layer self-priming stirring reactor

Abstract

The invention provides a three-layer self-priming stirring reactor, comprising a reactor kettle body, a hollow shaft and an air collecting hood, wherein the hollow shaft is vertically arranged in the reactor kettle body and penetrates the air collecting hood, an air inlet is arranged on the upper side wall of the hollow shaft, and an air outlet is arranged on the lower side wall; on the hollow shaft, an upper self-priming impeller, a middle stirring blade and a lower self-priming impeller are fixed at intervals from top to bottom; both the upper self-priming impeller and the lower self-priming impeller are hollow multi-channel impellers, a liquid phase inlet is provided between the outer side wall of the upper self-priming impeller and the inner side wall of the air collecting hood, and a gas-liquid mixing inlet is provided between the upper self-priming impeller and the hollow shaft; the upper inner side wall of the lower self-priming impeller is tightly sealed with the hollow shaft, an air inlet is provided on the inner side wall of the connecting part thereof with the hollow shaft, the air inlet is communicated with the air outlet, and a liquid inlet is provided on the outer side wall of the lower self-priming impeller. The self-priming stirring reactor of the present invention can reduce the critical speed during air intake and perform double-layer air intake to increase the overall gas holdup of the reactor.

Description

Technical Field

[0001] The invention belongs to the technical fields of chemical engineering, bioengineering and environmental engineering, and specifically relates to a three-layer self-priming stirring reactor. Background Art

[0002] Reactors are divided into packed tower reactors, mechanical stirring reactors, airlift reactors, and gas self-priming reactors. Each reactor is suitable for different reaction types. These reactors are widely used in gas-liquid contact reactions. After continuous development step by step, they are widely used in industries such as bioengineering, chemical engineering, sewage treatment, and metallurgy and chemical industry.

[0003] Packed tower reactors are not flexible enough and have poor mass transfer performance. Mechanically stirred reactors and airlift reactors have good mass transfer performance and are widely used in gas-liquid contact reactions in various biochemical and other fields, but they have high operating costs and consume more power per unit volume than self-priming reactors. Self-priming reactors do not require gas delivery equipment, and the gas that has not reacted completely and remains inside the reactor can be recycled and re-entered into the liquid phase, which is more economical and practical in industrial-scale reactions. Among these types of reactors, except for self-priming reactors, in the gas-liquid contact reaction process, the other types of reactors all require corresponding gas sources, and the gas delivery requires the corresponding gas supply equipment. Adding equipment separately to the reactor will make the overall installation of the reactor more complicated, with higher power loss and a greater chance of failure. Taking all these factors into consideration, self-priming reactors are receiving more and more attention in gas-liquid contact reactions.

[0004] Since the existing self-priming reactor has a high critical speed, its suction performance is poor at a lower speed, and the overall mixing performance of the reactor is poor. There are some dead zones inside, which is not conducive to the reaction environment of the microorganisms inside the reactor. Therefore, in order to address this shortcoming, a reactor with a simple structure, a low critical speed and good overall mixing performance is needed. Summary of the invention

[0005] In response to the above problems, the present invention provides a three-layer self-priming stirred reactor, which can reduce the critical speed during air intake, and use double-layer air intake to increase the overall gas content of the reactor. Combined with stirring blades, the overall mixing performance inside the reactor can be improved to meet the needs of different types of reactions.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] A three-layer self-priming stirring reactor comprises a reactor body, a hollow shaft and an air collecting hood, wherein the hollow shaft is vertically arranged in the reactor body, the upper end of the hollow shaft is connected to the output shaft of the motor through a coupling, the upper end of the air collecting hood is connected to the top cover of the reactor body, the hollow shaft passes through the air collecting hood, an air inlet is arranged on the upper side wall of the hollow shaft, and an air outlet is arranged on the lower side wall of the hollow shaft; an upper self-priming impeller, a middle stirring blade and a lower self-priming impeller are fixed on the outer side wall of the hollow shaft from top to bottom at intervals, the air collecting hood is located above the upper self-priming impeller, and the upper end of the upper self-priming impeller extends into the air collecting hood, and the air inlet is located above the upper end surface of the upper self-priming impeller; the upper self-priming impeller The suction impeller is a hollow multi-channel impeller, and the outer wall of the upper self-priming impeller is spaced from the inner wall of the air collecting hood to form a liquid phase inlet; a gap is left between the upper self-priming impeller and the hollow shaft to form a gas-liquid mixing inlet; the upper inner wall of the lower self-priming impeller is tightly sealed against the hollow shaft, and the lower self-priming impeller is a hollow multi-channel impeller, and an air inlet connected to its internal flow channel is provided on the inner wall of the connecting part with the hollow shaft, and the air inlet is connected to the air outlet at the lower part of the hollow shaft, and a plurality of liquid inlets connected to its internal flow channel are provided on the outer wall of the lower self-priming impeller, and the gas-liquid outlets of the internal flow channels of the upper and lower self-priming impellers are both located on their respective lower end surfaces.

[0008] Furthermore, the upper self-priming impeller includes an upper circular ring fixing portion and an upper frustum of a circular blade integrally formed and connected from top to bottom, the outer diameter of the upper circular ring fixing portion is the same as the outer diameter of the upper end surface of the upper frustum of a circular blade, and is smaller than the outer diameter of the lower end surface of the upper frustum of a circular blade, the lower end surface of the upper frustum of a circular blade is an upwardly inclined inclined surface, the internal flow channel of the upper self-priming impeller is arranged in the upper frustum of a circular blade, and the flow channel outlet is arranged on the lower end surface of the upper frustum of a circular blade.

[0009] Furthermore, the upper self-priming impeller has a plurality of internal flow channels which are evenly distributed inside the upper frustum cone annular blades, and the angle between the internal flow channels and the hollow shaft is 45°.

[0010] Furthermore, a plurality of upper self-priming impeller threaded holes are provided on the circumferential side of the upper circular ring fixing portion, and the upper self-priming impeller is connected to the hollow shaft via top screws passing through the upper impeller threaded holes.

[0011] Furthermore, the lower self-priming impeller includes a lower circular ring fixing part and a lower frustum of a ring blade which are integrally connected from top to bottom, the outer diameter of the lower circular ring fixing part is the same as the outer diameter of the upper end surface of the lower frustum of a ring blade and is smaller than the outer diameter of the lower end surface of the lower frustum of a ring blade, the lower end surface of the lower frustum of a ring blade is an upward inclined surface, the internal flow channel of the lower self-priming impeller is arranged in the lower circular ring fixing part and the lower frustum of a ring blade, the air inlet is arranged on the inner side wall of the lower circular ring fixing part, the liquid inlet is arranged on the outer side wall of the lower frustum of a ring blade, and the flow channel outlet is arranged on the lower end surface of the lower frustum of a ring blade.

[0012] Furthermore, the number of internal flow channels of the lower self-priming impeller is multiple, evenly distributed inside the lower annular fixing portion and the lower frustum annular blade, and the angle between the internal flow channel of the lower self-priming impeller and the hollow shaft is 45°.

[0013] Furthermore, a plurality of lower self-priming impeller threaded holes are opened on the circumferential side of the lower circular ring fixing portion, and the plurality of lower self-priming liquid level threaded holes are located above the internal flow channel of the lower circular ring fixing portion, and the lower self-priming impeller is connected to the hollow shaft by means of top screws passing through the lower impeller threaded holes.

[0014] Furthermore, the gas collecting hood is a straight hollow cylinder, connected to the inner top wall of the reactor body through a hanging ear, and the difference between the inner diameter of the gas collecting hood and the outer diameter of the upper circular ring fixing part is 10mm-20mm.

[0015] Furthermore, the middle-layer stirring blade is a downward pressure blade.

[0016] Furthermore, a baffle is provided on the vertical side wall of the reactor body.

[0017] The self-priming stirring reactor of the present invention, wherein the upper self-priming impeller and the self-priming impeller work on the following principle:

[0018] When the impeller rotates with the shaft, the liquid inside its flow channel gains kinetic energy and flows out from the outlet under the action of the impeller, forming a negative pressure at the outlet. The liquid and gas phases are sucked into the impeller from the gap between the inner side of the upper self-priming impeller and the hollow shaft, i.e., the gas-liquid mixing inlet, and are continuously dispersed into the reactor body as the impeller rotates. While ensuring that the impeller diameter is constant, its speed V1 remains unchanged. By changing the α angle, the actual liquid speed at the impeller outlet can be changed. The relationship is as follows: Figure 4 As shown, V1 is the horizontal velocity of the liquid phase at the blade tip, W is the angular velocity, R is the horizontal distance from the blade tip to the center of the shaft, and V is the actual velocity of the liquid phase at the blade tip. Therefore, when the impeller diameter is constant, at the same shaft speed, the liquid phase velocity in the impeller flow channel can be increased, and its critical suction speed can be effectively reduced; the principle of the lower self-priming impeller is the same as that of the upper self-priming impeller, the difference is that the liquid phase inlet is an opening on the impeller side wall.

[0019] The upper suction mode is to suck air inside the air collecting hood, and the lower blade suction is sucked through the hollow shaft. The suction mode is: when the impeller rotates with the shaft, the liquid phase inside the flow channel obtains kinetic energy and is discharged from the flow channel to the outside, causing negative pressure inside. Under the action of atmospheric pressure, the gas inside the air collecting hood and the hollow shaft presses the gas into the self-priming impeller. The self-priming impeller can increase the impeller tip speed by changing the angle between the flow channel and the vertical direction, effectively reducing the critical speed during suction.

[0020] The self-priming stirring reactor in the present invention has a simple structure, and the designed impeller can effectively reduce the critical speed. The stirring blades are combined to achieve uniform mixing of the entire flow field inside the reactor, and no external gas source is required, which can effectively reduce power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of the three-layer self-priming stirring reactor described in the present invention.

[0022] Figure 2 It is a schematic structural diagram of the upper self-priming impeller described in the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of the lower self-priming impeller of the present invention.

[0024] Figure 4 It is a schematic diagram of the working principle of the lower self-priming impeller described in the present invention.

[0025] Among them, 1-motor, 2-reactor body, 3-hollow shaft, 4-gas collecting hood, 5-upper self-priming impeller, 6-middle stirring blade, 7-lower self-priming impeller, 8-baffle, 3-1-air inlet, 3-2-air outlet, 51-upper circular ring fixing part, 52-upper truncated cone annular blade, 53-inner flow channel of upper self-priming impeller, 511-upper self-priming impeller threaded hole, 512-gas-liquid mixing inlet, 71-lower circular ring fixing part, 72-lower truncated cone annular blade, 711-lower self-priming impeller threaded hole, 712-air inlet, 721-liquid inlet, 722-gas-liquid outlet. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0027] like Figure 1-Figure 3As shown, a three-layer self-priming stirring reactor comprises a reactor kettle body 2, a hollow shaft 3 and an air collecting hood 4, wherein the hollow shaft 3 is vertically arranged in the reactor kettle body 2, the upper end of the hollow shaft 3 is connected to the output shaft of the motor 1 through a coupling, the upper end of the air collecting hood 4 is connected to the top cover of the reactor kettle body 2, the hollow shaft 3 is penetrated by the air collecting hood 4, an air inlet 31 is arranged on the upper side wall of the hollow shaft 3, and an air outlet 3-2 is arranged on the lower side wall of the hollow shaft 3; an upper self-priming impeller 5, a middle stirring blade 6 and a lower self-priming impeller 7 are fixed from top to bottom at intervals on the outer side wall of the hollow shaft 3, the air collecting hood 4 is located above the upper self-priming impeller 5, and the upper end of the upper self-priming impeller 5 extends into the air collecting hood 4, and the air inlet 31 is located above the upper end surface of the upper self-priming impeller 5;

[0028] The upper self-priming impeller 5 is a hollow multi-channel impeller, and a plurality of upper self-priming impeller internal flow channels are uniformly distributed inside it. The upper self-priming impeller 5 includes an upper circular ring fixing portion 51 and an upper truncated cone annular blade 52 that are integrally formed and connected from top to bottom. The outer wall of the upper circular ring fixing portion 51 is spaced apart from the lower part of the inner wall of the air collecting hood 4 to form a liquid phase inlet 54 for liquid phase supply during air suction. A gap is left between the upper self-priming impeller 5 and the hollow shaft 3 to form a gas-liquid mixing inlet 512, and a flow channel inlet connected to the internal flow channel is opened on its outer wall; a plurality of upper self-priming impeller threaded holes 511 are opened on the circumferential side of the upper circular ring fixing portion 51. The upper self-priming impeller 5 is connected to the hollow shaft 3 by a top screw passing through the upper self-priming impeller threaded hole 511; the outer diameter of the upper circular ring fixing portion 51 is the same as the outer diameter of the upper end surface of the upper truncated cone annular blade 52, and is smaller than the outer diameter of the lower end surface of the upper truncated cone annular blade 52, and the lower end surface of the upper truncated cone annular blade 52 is an inclined surface inclined upward, and the internal flow channel 53 of the upper self-priming impeller is arranged in the upper truncated cone annular blade 52, and the flow channel outlet of the internal flow channel of the upper self-priming impeller is arranged on the lower end surface of the upper truncated cone annular blade 52; the number of the internal flow channels 53 of the upper self-priming impeller is six, which are evenly distributed inside the upper truncated cone annular blade 52, and the angle between the internal flow channel 53 of the upper self-priming impeller and the hollow shaft 3 is 45°;

[0029] The upper inner wall of the lower self-priming impeller 7 is tightly sealed against the outer wall of the hollow shaft 3. The lower self-priming impeller 7 is a hollow multi-channel impeller, and an air inlet 712 connected to its internal flow channel is provided on the inner wall of the connecting portion with the hollow shaft 3. The air inlet 712 is connected to the air outlet 3-2 at the lower part of the hollow shaft 3, and a plurality of liquid inlets 721 are provided on the outer wall of the lower self-priming impeller 7; the lower self-priming impeller 7 comprises a lower circular ring fixing portion 71 and a lower truncated cone annular blade 72 which are integrally connected from top to bottom, and a plurality of lower self-priming impeller threaded holes 711 are provided on the circumferential side of the lower circular ring fixing portion 71, and the lower self-priming impeller 7 is connected to the hollow shaft 3 by means of a top screw passing through the lower self-priming impeller threaded hole 711; the outer diameter of the lower circular ring fixing portion 71 The outer diameter of the lower end surface of the lower truncated cone annular blade 72 is the same as that of the upper end surface of the lower truncated cone annular blade 72, and is smaller than the outer diameter of the lower end surface of the lower truncated cone annular blade 72. The lower end surface of the lower truncated cone annular blade 72 is an inclined surface inclined upward. The internal flow channel 73 of the lower self-priming impeller is arranged in the lower annular fixing portion 71 and the lower truncated cone annular blade 72. The air inlet 712 is arranged on the inner side wall of the lower annular fixing portion 71, and the liquid inlet 721 is arranged on the outer side wall of the lower truncated cone annular blade 72. The flow channel outlet of the internal flow channel of the lower self-priming impeller is arranged on the lower end surface of the lower truncated cone annular blade 72; the number of the internal flow channels 73 of the lower self-priming impeller is six, which are evenly distributed in the lower annular fixing portion 71 and the lower truncated cone annular blade 72. The angle between the internal flow channel of the lower self-priming impeller 7 and the hollow shaft 3 is 45°.

[0030] The gas collecting hood 4 is a straight hollow cylinder, which is connected to the inner top wall of the reactor kettle body 2 through a hanging ear. The difference between the inner diameter of the gas collecting hood 4 and the outer diameter of the upper circular ring fixing part is 10mm-20mm; the middle stirring blade 6 is a downward pressure blade; and a baffle 8 is provided on the vertical side wall of the reactor kettle body 2. Example

[0031] In this embodiment, the diameter of the plexiglass barrel is 300mm, the height is 550mm, the number of full baffles is selected as 3, the diameter of the self-priming impeller is 110mm, the width of the inner flow channel is 10mm, the taper is 45° with the vertical direction, and the critical speed is measured by changing the immersion depth of the upper self-priming blade to 100mm, 150mm and 200mm, and the results are compared with those of the ordinary self-priming impeller.

[0032] The results are shown in the following table.

[0033]

[0034] By changing the taper of the self-priming impeller, at the same speed, the absolute speed of the impeller tip becomes higher, the negative pressure is greater, and the critical speed of gas sucked into the reactor body is lower. At the same immersion depth, compared with the self-priming impeller without changing the taper, its critical speed is reduced by 20%-30%. Example

[0035] In this embodiment, the diameter of the organic glass barrel is 300mm, the height is 550mm, the number of full baffles is selected to be 3, the impeller diameter is 110mm, the inner flow channel width is 10mm, and the taper is 45° with the vertical direction. The distance between the upper self-priming impeller and the middle stirring blade is 1.5 times the diameter, and the distance between the middle stirring blade and the lower self-priming blade is 1.5 times the diameter, and the gas holdup and mass transfer experiments are analyzed respectively.

[0036] The self-priming stirring reactor of the present invention has a larger air intake at the same rotation speed, and the bubble size generated is uniform, the bubble size is concentrated in 1mm-3mm, the mixing performance is good, and there is no dead zone phenomenon inside the reactor body. On this basis, the gas-liquid interface area is increased, which is conducive to improving oxygen diffusion (DO concentration) and has a higher gas holdup and mass transfer rate. At the same rotation speed, its gas holdup is increased by 60% compared with the traditional self-priming reactor, and the volume oxygen mass transfer coefficient is increased by 60%.

[0037] Those skilled in the art should understand that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-layer self-priming stirred reactor, characterized in that: The invention comprises a reactor body, a hollow shaft and an air collecting hood, wherein the hollow shaft is vertically arranged in the reactor body, the upper end of the hollow shaft is connected to the output shaft of the motor through a coupling, the upper end of the air collecting hood is connected to the top cover of the reactor body, the hollow shaft passes through the air collecting hood, an air inlet hole is arranged on the upper side wall of the hollow shaft, and an air outlet hole is arranged on the lower side wall of the hollow shaft; an upper self-priming impeller, a middle stirring blade and a lower self-priming impeller are fixed at intervals from top to bottom on the outer side wall of the hollow shaft, the air collecting hood is located above the upper self-priming impeller, and the upper end of the upper self-priming impeller extends into the air collecting hood, and the air inlet hole is located above the upper end of the upper self-priming impeller; the upper self-priming impeller is a hollow multi-layer impeller. The channel type impeller, the outer wall of the upper self-priming impeller is spaced from the inner wall of the air collecting hood to form a liquid phase inlet; a gap is left between the upper self-priming impeller and the hollow shaft to form a gas-liquid mixing inlet; the upper inner wall of the lower self-priming impeller is tightly sealed against the hollow shaft, the lower self-priming impeller is a hollow multi-channel impeller, an air inlet connected to its internal flow channel is provided on the inner wall of the part connected with the hollow shaft, the air inlet is connected to the air outlet at the bottom of the hollow shaft, a plurality of liquid inlets connected to its internal flow channel are provided on the outer wall of the lower self-priming impeller, the gas-liquid outlets of the internal flow channels of the upper self-priming impeller and the lower self-priming impeller are both located on their respective lower end surfaces.

2. A three-layer self-priming stirred reactor according to claim 1, characterized in that: The upper self-priming impeller comprises an upper circular ring fixing portion and an upper frustum of a circular blade integrally formed and connected from top to bottom, the outer diameter of the upper circular ring fixing portion is the same as the outer diameter of the upper end surface of the upper frustum of a circular blade, and is smaller than the outer diameter of the lower end surface of the upper frustum of a circular blade, the lower end surface of the upper frustum of a circular blade is an upwardly inclined inclined surface, the internal flow channel of the upper self-priming impeller is arranged in the upper frustum of a circular blade, and the flow channel outlet is arranged on the lower end surface of the upper frustum of a circular blade.

3. A three-layer self-priming stirred reactor according to claim 2, characterized in that: The upper self-priming impeller has a plurality of internal flow channels which are evenly distributed inside the upper truncated cone annular blades, and the angle between the internal flow channels and the hollow shaft is 45°.

4. A three-layer self-priming stirred reactor according to claim 3, characterized in that: A plurality of upper self-priming impeller threaded holes are provided on the circumferential side of the upper circular ring fixing portion, and the upper self-priming impeller is connected to the hollow shaft via top screws penetrating the upper impeller threaded holes.

5. A three-layer self-priming stirred reactor according to claim 1, characterized in that: The lower self-priming impeller includes a lower circular ring fixing part and a lower frustum of a circular blade which are integrally connected from top to bottom. The outer diameter of the lower circular ring fixing part is the same as the outer diameter of the upper end surface of the lower frustum of a circular blade and is smaller than the outer diameter of the lower end surface of the lower frustum of a circular blade. The lower end surface of the lower frustum of a circular blade is an upwardly inclined inclined surface. The internal flow channel of the lower self-priming impeller is arranged in the lower circular ring fixing part and the lower frustum of a circular blade, the air inlet is arranged on the inner side wall of the lower circular ring fixing part, the liquid inlet is arranged on the outer side wall of the lower frustum of a circular blade, and the flow channel outlet is arranged on the lower end surface of the lower frustum of a circular blade.

6. A three-layer self-priming stirred reactor according to claim 5, characterized in that: The number of internal flow channels of the lower self-priming impeller is multiple, which are evenly distributed inside the lower annular fixing part and the lower truncated cone annular blade. The angle between the internal flow channel of the lower self-priming impeller and the hollow shaft is 45°.

7. A three-layer self-priming stirred reactor according to claim 6, characterized in that: A plurality of lower self-priming impeller threaded holes are opened on the circumferential side of the lower circular ring fixing part, and the plurality of lower self-priming impeller threaded holes are located above the internal flow channel of the lower circular ring fixing part. The lower self-priming impeller is connected to the hollow shaft by means of top screws passing through the lower impeller threaded holes.

8. A three-layer self-priming stirred reactor according to claim 2, characterized in that: The gas collecting hood is a straight hollow cylinder, connected to the inner top wall of the reactor body through a hanging ear, and the difference between the inner diameter of the gas collecting hood and the outer diameter of the upper circular ring fixing part is 10mm-20mm.

9. A three-layer self-priming stirred reactor according to claim 1, characterized in that: The middle layer stirring blade is a downward pressure blade.

10. A three-layer self-priming stirred reactor according to claim 1, characterized in that: A baffle is provided on the vertical side wall of the reactor body.

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