CN113813812B

CN113813812B - Novel stirring paddle, stirring paddle system suitable for fermentation of high-viscosity materials and fermentation method

Info

Publication number: CN113813812B
Application number: CN202111176043.1A
Authority: CN
Inventors: 王继乾; 朱虎; 李慧; 柳建林; 李本超; 徐海; 姬思雪
Original assignee: China University of Petroleum East China; Fujian Normal University
Current assignee: China University of Petroleum East China; Fujian Normal University
Priority date: 2021-10-09
Filing date: 2021-10-09
Publication date: 2022-09-30
Anticipated expiration: 2041-10-09
Also published as: CN113813812A

Abstract

The invention relates to a novel stirring paddle, a stirring paddle system suitable for fermenting high-viscosity materials and a fermentation method, wherein the novel stirring paddle comprises a first hub, a supporting rod and a first blade; the first paddle is fixed on the support rod; the first paddle is a curved thin plate, the curved surface is a cylindrical surface, and the curvature of the curved surface is 0.15. The invention has the beneficial effects that: the bending design of the blades can ensure that the stirring blades can promote the axial flow of the fermentation liquor while generating radial flow, can cause stronger vortex, fully mixes the materials, and simultaneously provides a space for the fluid to pass through the blades by the cambered surfaces formed by the blades, thereby avoiding the generation of air pockets behind the blades; the cross design of inferior bracing piece mutually perpendicular can not only make the stirring rake form the vortex at the wheel hub scope, can also form the stirring effect in certain extent about wheel hub, can increase substantially the effect scope of stirring rake, under the prerequisite that keeps rotational speed and consumption unchangeable, can to a great extent improve material mixing ability, realizes providing high axial circulation flow with the low energy consumption.

Description

Novel stirring paddle, stirring paddle system suitable for fermentation of high-viscosity materials and fermentation method

Technical Field

The invention relates to the field of mechanical equipment of biological engineering and chemical engineering, in particular to a novel stirring paddle, a stirring paddle system suitable for fermenting high-viscosity materials and a fermentation method.

Background

In the high molecular polysaccharide fermentation industry, research and development of efficient fermentation tanks generate strong driving force for development of stirring equipment. In the process of fermenting high molecular polysaccharide, along with the continuous accumulation of products, the viscosity of fermentation liquor is continuously increased, the effect of mixing and mass transfer in a reactor is continuously deteriorated, and the mixing and mass transfer in the fermentation process become limiting factors in the fermentation process. Therefore, higher requirements are put on the design of the stirring paddle of the fermentation tank: not only is good mixing performance required, but consideration is also given to how to reduce mechanical energy consumption and production costs.

Disclosure of Invention

In view of the above, the invention provides a novel stirring paddle, a stirring paddle system suitable for fermenting high-viscosity materials and a fermentation method, and aims to solve the problems in the prior art.

Specifically, the novel stirring paddle comprises a first hub, a support rod and a first blade; the first paddle is fixed on the support rod; the first paddle is a curved thin plate, the curved surface is a cylindrical surface, and the curvature of the cylindrical surface is 0.15;

the middle of the first paddle is a rectangular thin plate after being unfolded, the two sides of the first paddle are arc-shaped thin plates,

the first curved-surface paddle is formed by oppositely turning and folding the surfaces on two sides of a diagonal line along the perpendicular line from the other two vertexes to the diagonal line by taking the diagonal line of the rectangle as a reference.

The structure can ensure that the stirring paddle can promote the axial flow of fermentation liquor while generating radial flow, can cause stronger vortex, and ensures that materials are fully mixed, and meanwhile, the cambered surface formed by the paddle can provide a space for fluid to pass through the paddle, thereby avoiding the generation of air pockets behind the paddle.

On the basis, the support rods comprise a main support rod and a secondary support rod, the main support rod is fixed on the first wheel hub, the secondary support rod is vertically fixed on the main support rod, and the main support rod is vertical to one surface where the axis of the first wheel hub is located; the side of the rectangular thin plate of the first paddle is fixed to the end of the secondary support rod and connected with the central point of the side of the rectangular thin plate of the secondary support rod, the straight line of the central point of the opposite side of the central point of the side of the rectangular thin plate of the secondary support rod and the axis of the secondary support rod are arranged on the same straight line.

On the basis, the number of the main supporting rods is multiple, and the multiple main supporting rods are arranged at the same horizontal height and are uniformly distributed along the first hub; each main supporting rod is provided with 4 secondary supporting rods, and the 4 secondary supporting rods are divided into two groups; the two secondary supporting rods in the same group are symmetrical to one plane where the axes of the main supporting rods are located; the two groups of secondary supporting rods are vertical to each other.

This kind of a main tributary vaulting pole and set up the whole cross structure that is of secondary bracing piece on this main tributary vaulting pole, can not only make the stirring rake form the vortex near wheel hub scope, can also form the stirring in certain extent about wheel hub, can increase substantially the scope that the stirring rake played, under the unchangeable prerequisite of the rotational speed and the consumption that keep the stirring rake, can to a great extent improve material mixing ability, realize providing high axial circulation flow with the low energy consumption.

On the basis, the projection distance of the two secondary support rods of different groups in the extending direction of the main support rod is more than or equal to 1/2 of the projection length of the first blade on the main support rod and is less than the projection length of the first blade on the main support rod. The structure can lead the first blades on the secondary support rods of different groups to form staggered spatial distribution, thereby furthest increasing the stirring area range.

On the basis, one group of the secondary support rods and the longitudinal section of the first hub form an included angle of 20-40 degrees. The structure ensures that the blades arranged on different secondary supporting rods are distributed in a staggered way, so that the stirring area range in the depth direction is enlarged.

A stirring paddle system suitable for fermentation of high-viscosity materials is characterized in that 2 stirring paddles are arranged on a stirring shaft and respectively comprise a first stirring paddle and a second stirring paddle, the first stirring paddle and the second stirring paddle are arranged up and down along the stirring shaft, and a fluid passing interval is reserved between the first stirring paddle and the second stirring paddle; the first stirring paddle and the second stirring paddle have the same rotating direction and are consistent with the rotating direction of the stirring shaft.

As another specific scheme, 1 curved cross stirring paddle and 1 flat folding stirring paddle in the invention are arranged on the stirring shaft;

the flat folding stirring paddle comprises a second hub, a disc and second blades, wherein the disc is fixed on the periphery of the second hub, the second blades comprise flat blades and folding blades, and the flat blades and the folding blades are fixed on the disc along the radial direction of the disc and are uniformly distributed at intervals; the whole hinge is V-shaped and comprises two blades, the two blades are rectangular thin plates, and the opening direction of the two blades is consistent with the rotating direction of the second paddle; the hinge is fixedly connected with the disc at the joint of the two blades; the flat blade is a rectangular thin plate, and is fixedly connected with the disc at the center line of the length direction; the flat leaf extends out of the outer side of the disc to form a first extending part, the hinge extends out of the outer side of the disc to form a second extending part, and the length of the second extending part is greater than that of the first extending part along the radial direction of the disc. The structure combines the flat leaves and the folded leaves, a small airtight area can be formed between two different blades, and gas can circulate in the space, so that the retention time of the gas between the two blades is longer, more bubbles are dispersed in the culture solution through the rotation of the blades, the dissolved oxygen capacity of the culture solution is improved, and the dissolved oxygen requirement in a high-viscosity fermentation system is better met.

On the basis, the included angle of the V-shaped opening of the flap is 60 degrees, the shearing performance of the paddle can be improved due to the structural form of the flap, the mass transfer area of the fermentation liquor is increased under the effective shearing action, more gas enters the fermentation liquor, and therefore the mass transfer and oxygen transfer effects of the fermentation liquor are improved.

Furthermore, one side of each blade of the hinge, which is far away from the connection part of the two blades, is provided with an inwards concave notch groove. Specifically, the V-shaped vertex of the notch groove is located at the intersection point of two diagonal lines of the rectangular blade, the notch groove is V-shaped, the included angle of the V-shaped opening is 90-120 degrees, preferably, the included angle of the V-shaped opening of the notch groove is 115 degrees, and the structure can further prevent the generation of air pockets.

On the basis, the height of the flat leaf is smaller than or equal to that of the folded leaf and is larger than or equal to the height between V-shaped vertexes of two notch grooves on the same folded leaf. The structure enables the gas to circulate between the two blades, reduces the overflow of the gas, and further ensures that the gas can be temporarily stored in a closed space, thereby strengthening the gas dispersion.

On the basis, the length ratio of the flat leaf to the hinge leaf along the radial direction of the disc is 1: 1.

on the basis, the length ratio of the first extension part to the second extension part along the radial direction of the disc is 1: 2.5.

The invention has the beneficial effects that: the bending design of the first paddle can enable the stirring paddle to generate radial flow and simultaneously promote the axial flow of fermentation liquor, stronger vortex can be caused, materials are fully mixed, and meanwhile, the cambered surface formed by the paddles can provide space for fluid to pass through the paddles, so that cavitation is avoided after the paddles; the cross design of inferior bracing piece mutually perpendicular can not only make the stirring rake form the vortex at the wheel hub scope, can also form the stirring effect in certain extent about wheel hub, can increase substantially the effect scope of stirring rake, under the prerequisite that keeps rotational speed and consumption unchangeable, can to a great extent improve material mixing ability, realizes providing high axial circulation flow with the low energy consumption.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a schematic isometric view of the novel paddle of this patent;

fig. 2 is a schematic view of the first blade in example 1 of this patent deployed;

fig. 3 is a schematic structural view of a first blade in embodiment 1 of the present patent;

FIG. 4 is a schematic structural view of the first hub according to embodiment 1 of the present patent;

FIG. 5 is a schematic diagram of the relative positions of the main support bar and the sub-support bar in example 1 of this patent;

FIG. 6 is a schematic view of the relative positions of the secondary support bar and the first hub in embodiment 1 of this patent;

fig. 7 is a schematic structural view of a stirring paddle system in embodiment 3 of this patent (both the first stirring paddle and the second stirring paddle are curved cross stirring paddles);

FIG. 8 is a schematic structural view of a paddle system in example 2 of this patent (the first paddle is a curved cross paddle, and the second paddle is a flat folding paddle);

FIG. 9 is an isometric view of a flat folding paddle according to example 2 of this patent;

FIG. 10 is a schematic top view of a flat folding paddle according to example 2 of this patent;

FIG. 11 is a schematic structural view of a second hub of a flat folding paddle in example 2 of the present patent;

FIG. 12 is a schematic view showing a disk structure of a flat folding paddle according to example 2 of this patent;

FIG. 13 is a schematic view showing a flat blade structure of a flat folding paddle according to example 2 of this patent;

FIG. 14 is a front view of a hinge of a flat-folding paddle according to example 2 of this patent;

FIG. 15 is a schematic side view of a flat folding paddle according to example 2 of this patent;

FIG. 16 is a schematic structural view of a hinge of a flat folding paddle in example 2 of this patent, viewed from the A direction;

FIG. 17 is a schematic view showing the relative positions of a flat blade and a hinge of a flat-folding paddle according to example 2 of this patent;

FIG. 18 is a schematic view showing the relative position of a flat blade and a flap of a flat-folding paddle in the direction B in example 2 of this patent;

FIG. 19 is a schematic diagram showing the relative position between the flap side and the flat blade of the stirring paddle for flat folding in example 2 of this patent.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

Example 1

A novel stirring paddle is shown in figure 1 and comprises a first hub 1, a support rod 2 and a first blade 3; the first paddle 3 is fixed on the support rod 2; the first paddle 3 is a curved thin plate, the curved surface is a cylindrical surface, and the curvature of the cylindrical surface is 0.15;

specifically, as shown in fig. 2 and 3, the first blade 3 is formed by folding the surfaces of the two sides of the diagonal line C in the opposite direction with the rectangular diagonal line C as a reference along the perpendicular lines from the other two vertexes to the diagonal line, i.e., D and D' in fig. 2, after being unfolded, the middle of the first blade is a rectangular thin plate and the two sides of the first blade are arc-shaped thin plates. The curve D and the curve D ' after being turned over are both arc lines, the curvatures of the curve D and the curve D ' are equal and are both 0.15, and the curved surfaces where the curve D and the curve D ' are located are cylindrical surfaces with the curvatures of 0.15.

On the basis, the support rod 2 comprises a main support rod 2-1 and a secondary support rod 2-2, the main support rod 2-1 is fixed on the first hub 1, the secondary support rod 2-2 is vertically fixed on the main support rod 2-1, and the main support rod 2-1 is vertical to a plane where the axis of the first hub 1 is located; the main supporting rods 2-1 are multiple, the multiple main supporting rods 2-1 are uniformly distributed at the same horizontal height along the circumferential direction of the first hub 1, and the multiple main supporting rods 3-1 are radial along the center of the first hub 1.

Specifically, as shown in fig. 1 and 4, the first hub 1 is a cylindrical hub, a first mounting hole 1-1 for connecting a stirring shaft (see fig. 7 and 8) is formed in the middle of the first hub 1, and a second mounting hole 1-2 used in cooperation with the main support rod 2-1 is formed in the side surface of the first hub 1; the main supporting rods 2-1 are uniformly distributed along the first hub 1, and the included angle alpha formed by the central axes of two adjacent second mounting holes 1-2 is equal in size. Preferably, in the embodiment, the number of the main support rods 2-1 is 3, and an included angle α between central axes of two adjacent second mounting holes 1-2 is 120 degrees; each main support rod 2-1 is provided with 4 secondary support rods 2-2, and the 4 secondary support rods 2-2 are divided into two groups; two minor support bars 2-2 in the same group are symmetrical to a mirror image where the axis of the major support bar 2-1 is located, where a plane refers to: passing through the axis of the main support bar 2-1 and perpendicular to the plane of the two secondary support bars 2-2 in the same group; the two groups of secondary supporting rods 2-2 are vertical to each other.

The main support rod 2-1 and the secondary support rod 2-2 arranged on the main support rod 2-1 are integrally in a cross structure, so that not only can the stirring paddle form vortex in a range near the hub, but also stirring can be formed in a certain range above and below the hub, the acting range of the stirring paddle can be greatly improved, the material mixing capacity can be improved to a great extent on the premise of keeping the rotating speed and the power consumption of the stirring paddle unchanged, and the high axial circulation flow can be provided with low energy consumption.

On the basis, as shown in fig. 5, the projection distance L of the two secondary support bars 2-2 of different groups in the extending direction of the main support bar 2-1 is greater than or equal to 1/2 of the projection length of the first blade 3 on the main support bar 2-1 and smaller than the projection length of the first blade 3 on the main support bar 2-1. Because the first blades 3 are arranged on the secondary supporting rods 2-2, the first blades on the secondary supporting rods of different groups can form staggered spatial distribution, so that the stirring area range is enlarged to the maximum extent.

On the basis, as shown in fig. 6, one group of the secondary support rods 2-2 forms an included angle of 20-40 degrees with the longitudinal section of the first hub 1, wherein the longitudinal section refers to the plane of the central axis of the first hub 1 and the central axis of the primary support rod 2-1. Preferably, in this embodiment, an included angle β between one set of the secondary support rods 2-2 and the longitudinal section of the first hub 1 is 30 °, and an included angle γ between the other set of the secondary support rods 2-2 and the cross section of the first hub 1 is 60 °. The structure ensures that the blades arranged on the different secondary supporting rods are distributed in a staggered way in height, thereby enlarging the range of the stirring area in the depth direction.

Example 2

A stirring paddle system (a power driving device is not shown) suitable for fermentation of high-viscosity materials is characterized in that two stirring paddles, namely a first stirring paddle 5 and a second stirring paddle 6, are arranged on a stirring shaft 4 and are coaxially arranged along the stirring shaft 4; the first stirring paddle 5 is arranged above the second stirring paddle 6, and a gap for fluid to pass through is reserved between the first stirring paddle and the second stirring paddle; the first stirring paddle 5 and the second stirring paddle 6 have the same rotating direction and are consistent with the rotating direction of the stirring shaft 4.

As a specific scheme, as shown in fig. 8, 1 new paddle in example 1 and 1 flat folding paddle are arranged on the stirring shaft 4; the novel paddle of example 1 was on top and the flat fold paddle was on the bottom.

As shown in fig. 9 to 11, the flat-folding stirring paddle comprises a second hub a1, a disk a2 and a second paddle A3, the disk a2 is fixed on the outer periphery of the second hub a1, the second paddle A3 comprises a flat blade A3-1 and a hinge A3-2, and the flat blade A3-1 and the hinge A3-2 are fixed on the disk a2 along the radial direction of the disk a2 and are uniformly spaced; the hinge A3-2 is integrally V-shaped and comprises two blades A3-22, the two blades A3-22 are both rectangular thin plates, and the opening direction of the two blades A3-22 is consistent with the rotating direction of the second blade A3; the hinge A3-2 is fixedly connected with the disc A2 at the joint of the two blades A3-22; the flat leaf A3-1 is a rectangular thin plate, and the flat leaf A3-1 is fixedly connected with the disc A2 at the center line of the length direction; the flat leaf A3-1 extends out of the disc A2 to form a first extension A3-11, the hinge A3-2 extends out of the disc A2 to form a second extension A3-21, and the length of the second extension A3-21 is larger than that of the first extension A3-11 along the radial direction of the disc A2. The hinge A3-2 is not directly connected to the hub, and the gas is further diffused under the liquid level through the disc A2, so that the gas is prevented from directly overflowing the liquid level around the hub without being dispersed.

Specifically, as shown in fig. 9 and 11, the second hub a1 is a cylinder, and a first through hole a1-1 is formed in the middle of the second hub a1, and the first through hole a1-1 is used for mounting the second hub a1 on a stirring shaft (as shown in fig. 8), so as to perform industrial stirring operation.

As shown in fig. 12, a second through hole a2-1 for mounting the second hub a1 is opened at the middle of the disc a2, and as shown in fig. 10, the disc a2 is fixedly connected to the outer circumference of the second hub a 1. The disc A2 is provided with a first mounting groove A2-2 and a second mounting groove A2-3 which are opened inwards from the outer edge of the disc A2 along the radial direction of the disc A2, and the first mounting groove A2-2 and the second mounting groove A2-3 are uniformly distributed on the disc A2 at intervals.

As shown in fig. 13, the flat blade A3-1 is provided with a third mounting groove A3-12 for cooperating with the first mounting groove a 2-2. referring to fig. 12, the sum of the lengths of the first mounting groove a2-2 and the third mounting groove A3-12 is equal to the difference between the outer diameter and the inner diameter of the disk, which are both radius values. When the flat blade A3-1 is installed, the third installation groove A3-12 is inserted into the disc A2 through the first installation groove A2-2, and then the flat blade A3-1 is fixedly connected with the disc A2.

As shown in FIG. 14, the hinge A3-2 includes two leaves A3-22, and a crease A3-23 is formed at the junction of the two leaves A3-22. Specifically, as a scheme, the hinge A3-2 is a rectangular thin plate, and is folded by taking a center line in the length direction as a symmetry axis, two blades A3-22 are respectively formed on two sides of the center line, and a crease A3-23 is formed at the center line; as another specific scheme, the two blades A3-22 are rectangular thin plates, after being formed into a V shape, the connecting parts of the two blades A3-22 are fixed by adopting a welding mode and the like, the connecting parts of the two blades A3-22 form creases A3-23, and the two blades A3-22 which are fixedly connected are hinges A3-2. Referring to fig. 12, when the hinge A3-2 is installed, the fold A3-23 is inserted into the disc a2 through the second installation groove a2-3, and then the hinge A3-2 is fixedly connected to the disc a 2.

Preferably, the flat leaves A3-1 and the hinges A3-2 are radially arranged and fixed on the disk a2 relative to the second hub a1 and are evenly spaced.

The structure combines the flat leaf A3-1 and the flap A3-2, a small sealed area can be formed between the two different blades, gas can circulate in the space, and the retention time of the gas between the two blades is longer, so that more bubbles are dispersed in the culture solution through the rotation of the blades, the oxygen dissolving capacity of the culture solution is improved, and the oxygen dissolving requirement in a high-viscosity fermentation system is better met.

On this basis, as shown in fig. 15, the angle a α of the V-shaped opening of the hinge a3-2 is 60 °. The structure of the hinge can increase the shearing property of the blades, promote the mass transfer area of the fermentation liquor to be increased under the effective shearing action, and enable more gas to enter the fermentation liquor, thereby improving the mass transfer and oxygen transfer effects of the fermentation liquor.

Further, as shown in fig. 14 and 16, each of the blades A3-22 of the hinge A3-2 is provided with a concave notch groove A3-24 at a side away from the junction of the two blades A3-22. Specifically, the notch grooves A3-24 are V-shaped, and the included angle A beta of the notch grooves A3-24 is 90-120 degrees; the V-shaped vertex of the notch grooves A3-24 is located at the intersection of two diagonals of the rectangular blades A3-22. Preferably, the included angle a β of the notch grooves a3-24 is 115 °, and as the blade rotates, a certain space is formed behind the blade to form air pockets, which is not beneficial to the dispersion of gas, and such a structure can effectively prevent the generation of air pockets.

On the basis, as shown in fig. 17-19, the height of the flat leaf A3-1 is less than or equal to the height d of the hinge A3-2 ₁ And is greater than or equal to the height d between the V-shaped vertexes of the two notch grooves A3-24 on the same hinge A-2 ₂ . The design can enable gas to circulate between the two paddles, reduce the overflow of the gas and further ensure that the gas can be temporarily stored in a closed space, thereby strengthening the gas dispersion and simultaneously improving the turning capacity of the paddles on materials.

On the basis, the length ratio of the flat leaf A3-1 to the folded leaf A3-2 along the radial direction of the disc A2 is 1: 1.

on this basis, the length ratio of the first extension A3-11 to the second extension A3-21 in the radial direction of the disc A2 is 1: 2.5.

That is, the flat blade A3-1 and the flap A3-2 have the same length along the radial direction of the disc a2, and the flap A3-2 is installed at the outer side of the disc a2 relative to the flat blade A3-1, so that the structure enables gas to be discharged along the intersection of the two blades during the rotation of the blades, thereby ensuring the sufficiency of gas discharge in the two blades and avoiding gas to be retained between the blades.

Example 3

In the embodiment, the influence of the stirring system of the invention and the traditional stirring system on the fermentation effect is verified based on the mixing and mass transfer characteristics of different stirrers in the specific fermentation process.

Respectively using the stirring system of example 2 (as shown in fig. 8, the length ratio of the tank diameter of the fermentation tank to the maximum diameter of the stirring paddle is 2:1, the maximum diameter of the stirring paddle refers to the vertical distance from the outermost end of the first blade 3 far away from the first hub 1 to the central axis of the first hub 1 or the vertical distance from the outermost end of the fold A3-23 of the hinge A3-2 far away from the second hub A1 to the central axis of the second hub A1, the maximum diameters of the two types of stirring paddles can be the same.), a conventional disk straight blade turbine type stirring paddle system (only having a flat blade structure) and a stirring system provided with 2 stirring paddles in example 1 on a stirring shaft 4 (as shown in fig. 7, the length ratio of the tank diameter of the fermentation tank to the maximum diameter of the stirring paddles is 2:1, and the maximum diameter of the stirring paddles refers to the vertical distance from the outermost end of the first blade 3 far away from the first hub 1 to the central axis of the first hub 1). The fermentation cylinder adopts 7.5L triplet fermentation cylinder, and the model is: labfors 5, the fermentation process is conventional, will not be described in detail, only for a brief introduction. The fermentation used was performed using Sphingomonas WG (Sphingomonas. WG) which was stored in the laboratory.

Seed culture: a 250mL triangular flask was filled with 50mL of fresh seed medium comprising: 10g/L glucose, 1g/L yeast extract, 5g/L peptone, 2g/L potassium dihydrogen phosphate and 0.1g/L magnesium sulfate. Selecting a colony with bright color and plump colony morphology in a seed culture medium, putting the colony in a shaking table of 165r/min, culturing for 36h at constant temperature at 28 ℃, inoculating 5% of the colony into a fresh seed culture medium, putting the colony in the shaking table of 165r/min, and culturing for 24h at constant temperature at 28 ℃ to activate the seeds for the second time.

A 7.5L fermentor was charged with 4L of fresh fermentation medium comprising: 70g/L of sucrose, 3.4g/L of yeast extract, 3g/L of dipotassium phosphate and 0.1g/L of magnesium sulfate. Two layers of stirring paddles are arranged in the fermentation tank, and the tank diameter is as follows: the diameter of the paddle was 2:1, and then sterilized at 115 ℃ for 30 min. And inoculating a seed culture solution with the volume ratio of 5% after cooling, introducing sterile air with the volume ratio of 1vvm, setting the rotating speed of the stirring paddle at 400r/min, and culturing at the constant temperature of 32.5 ℃ for 72 hours.

After the fermentation was completed, the yield of sphingosine gum in the fermentor using the fermentation system in example 2 was 35.5g/L, and the product viscosity was 61.675 pas; the yield of the sphingosine gum in a fermentation tank using a stirring system in which 2 stirring paddles in example 1 are arranged on a stirring shaft 4 is 22g/L, and the product viscosity is 41.089 pas; the yield of the sphingosine gum in a fermentation tank adopting a traditional disc straight blade turbine type stirring paddle is 20g/L, and the product viscosity is 34.56 pas.

After bottom air inlet is adopted in the fermentation tank, the flat-folded stirring paddle breaks air bubbles, so that large bubbles are dispersed into smaller bubbles, and a gas-liquid contact interface is increased, so that the mass transfer rate of oxygen is improved. In terms of bubble crushing capability, the flat-folded paddle is superior to the curved cross paddle because the flat-folded paddle stirring paddle is provided with the disc, so that gas can be prevented from directly overflowing from the periphery of the shaft to the liquid level without being dispersed, and the curved cross stirring paddle can better promote the material mixing and gas distribution in the fermentation tank above the shaft, so that the stirring paddle system of the embodiment 2 can effectively submit the fermentation effect for the fermentation liquid with high viscosity.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. The novel stirring paddle is characterized by comprising a first hub (1), a support rod (2) and a first paddle (3); the first paddle (3) is fixed on the support rod (2); the first paddle (3) is a curved thin plate, the curved surface is a cylindrical surface, and the curvature of the cylindrical surface is 0.15;

the middle of the first paddle (3) is a rectangular thin plate after being unfolded, the two sides of the first paddle are arc-shaped thin plates,

the curved first paddle (3) is formed by oppositely turning and folding the surfaces on two sides of a diagonal line along the perpendicular line from the other two vertexes to the diagonal line by taking the rectangular diagonal line as a reference;

the supporting rod (2) comprises a main supporting rod (2-1) and a secondary supporting rod (2-2), the main supporting rod (2-1) is fixed on the first hub (1), the secondary supporting rod (2-2) is vertically fixed on the main supporting rod (2-1), and the main supporting rod (2-1) is vertical to one plane where the axis of the first hub (1) is located; the side face of the rectangular thin plate of the first paddle (3) is fixed at the end part of the secondary support rod (2-2) and is connected with the straight line where the central point of the side face of the rectangular thin plate of the secondary support rod (2-2) and the central point of the opposite side face of the rectangular thin plate of the secondary support rod are located and the axis of the secondary support rod (2-2) is arranged on the same straight line.

2. The new type of mixing paddle according to claim 1, characterized in that the main support rod (2-1) is multiple, and the multiple main support rods (2-1) are arranged at the same level and uniformly distributed along the first hub (1); each main supporting rod (2-1) is provided with 4 secondary supporting rods (2-2), and the 4 secondary supporting rods (2-2) are divided into two groups; the two secondary supporting rods (2-2) in the same group are symmetrical to one plane where the axes of the main supporting rods (2-1) are located; the two groups of secondary supporting rods (2-2) are vertical to each other.

3. The new mixing paddle according to claim 2, characterised in that the projected distance of the two secondary support bars (2-2) of different sets in the extension direction of the main support bar (2-1) is greater than or equal to 1/2 of the projected length of the first blade (3) on the main support bar (2-1) and < the projected length of the first blade (3) on the main support bar (2-1).

4. A new mixing paddle according to claim 3, characterised in that one set of secondary support bars (2-2) is angled at 20-40 ° to the longitudinal section of the first hub (1).

5. A stirring paddle system suitable for fermentation of high-viscosity materials, which is characterized in that 1 stirring paddle according to any one of claims 1-4 and 1 flat folding stirring paddle are arranged on a stirring shaft (4);

the flat folding stirring paddle comprises a second hub (A1), a disc (A2) and a second paddle (A3), the disc (A2) is fixed on the periphery of the second hub (A1), the second paddle (A3) comprises a flat blade (A3-1) and a hinge (A3-2), and the flat blade (A3-1) and the hinge (A3-2) are fixed on the disc (A2) along the radial direction of the disc (A2) and are uniformly spaced;

the hinge (A3-2) is integrally V-shaped and comprises two blades (A3-22), the two blades (A3-22) are both rectangular thin plates, and the opening direction of the two blades is consistent with the rotating direction of the second paddle (A3); the hinge (A3-2) is fixedly connected with the disc (A2) at the joint of the two blades (A3-22);

the flat leaf (A3-1) is a rectangular thin plate, and the flat leaf (A3-1) is fixedly connected with the disc (A2) at the center line of the length direction;

the flat leaf (A3-1) extends out of the disc (A2) to form a first extension part (A3-11), the hinge (A3-2) extends out of the disc (A2) to form a second extension part (A3-21), and the length of the second extension part (A3-21) is greater than that of the first extension part (A3-11) along the radial direction of the disc (A2).

6. The paddle system for fermenting high-viscosity materials according to claim 5, wherein the angle of the V-shaped opening of the hinge (A3-2) in the flat-folded paddle is 60 degrees.

7. The paddle system suitable for fermentation of high viscosity materials according to claim 5, wherein each blade (A3-22) of the flap (A3-2) in a flat-folded paddle is provided with a concave notch groove (A3-24) on the side away from the junction of the two blades (A3-22); the notch grooves (A3-24) are V-shaped, and the included angle of the notch grooves (A3-24) is 90-120 degrees; the V-shaped vertex of the notch groove (A3-24) is positioned at the intersection of two diagonals of the rectangular blade (A3-22).

8. The paddle system suitable for fermentation of high viscosity materials according to claim 5, wherein the height of the flat blade (A3-1) in the flat-folded paddle is less than or equal to the height of the flap (A3-2) and greater than or equal to the height between the V-shaped vertexes of two notched grooves (A3-24) on the same flap (A3-2).

9. A method suitable for fermentation of high viscosity materials, characterized in that the stirring paddle according to any one of claims 1-4 or the stirring paddle system according to any one of claims 5-8 is used, the length ratio of the tank diameter to the maximum diameter of the stirring paddle during fermentation is 2:1, and the stirring speed is 400 r/min.