CN212247009U

CN212247009U - Large mixing stirring type facultative hydrolysis reactor

Info

Publication number: CN212247009U
Application number: CN202020345695.8U
Authority: CN
Inventors: 朱娜; 陈鹏; 李磊; 王明明; 赵业华; 孙德寿; 李旭源
Original assignee: Beijing Yingherui Environmental Technology Co ltd
Current assignee: Beijing yingherui Environmental Technology Co.,Ltd.
Priority date: 2020-02-27
Filing date: 2020-03-18
Publication date: 2020-12-29
Anticipated expiration: 2030-03-18
Also published as: CN111218385A; CN111218385B

Abstract

The utility model discloses a large mixing stirring type facultative hydrolysis reactor, which comprises a body and a stirrer; the stirrer comprises a vertical shaft vertical main stirrer and an obliquely inserted auxiliary stirrer, and the two types of stirrers are arranged by deviating from the center of the body. The utility model forms the superposition of a vertical downward plug flow field and an anticlockwise rotating flow field by mutually matching the vertical shaft vertical main stirrer and the inclined plug auxiliary stirrer which are eccentrically arranged, strengthens the formation of liquid level and can bring straw materials into underwater vortex, and leads the bottom of the reactor to form disturbance and prevent sedimentation, thus leading the straw with smaller bulk density to overcome the buoyancy and be fully mixed with feed liquid for stirring; furthermore, the volume of the reactor is reduced under the constraint of stirring action, the volume of a single hydrolysis reactor is increased, the number of the reactors can be reduced, and the civil engineering investment cost is saved; in addition, after the number of the reactors is reduced, corresponding equipment and control systems are also reduced, and the equipment investment is reduced.

Description

Large mixing stirring type facultative hydrolysis reactor

Technical Field

The utility model relates to the technical field of biogas fermentation engineering, in particular to a large mixing stirring type facultative hydrolysis reactor which is suitable for taking straws as raw materials.

Background

Chinese patent CN105132469B discloses a process for pretreating lignocellulose by using a facultative manner, and provides a biochemical process for quickly hydrolyzing dry straws. The method can lead the methane content in the biogas produced by the crop straw raw material to reach 57 percent, and greatly shorten the production time of preparing the biogas by straw fermentation.

In the process of adopting the process, the dry straws need to be crushed to be less than 2cm, and are put into the facultative hydrolysis reactor after being subjected to wire rolling treatment. However, the bulk density of the dry straw after the crushing and kneading treatment is only 100kg/m³After the dry straw is put into a facultative pretreatment reactor (facultative hydrolysis reactor), because the density of the dry straw is lighter than that of water and the air flotation effect of micro-aeration, a floating layer is easily formed in the facultative reactor, the accumulated straw continuously floats, and a thick shell layer is formed on the liquid level layer of the reactor, so that the function of the stirrer for mixing and homogenizing is invalid, particularly, the molecular chemical bond of the dry straw has strong hydrophobicity and is not fully contacted and mixed with water, and microorganisms and enzymes are difficult to enter the interior of straw fibers, so that the hydrolysis biochemical reaction of the microorganisms is difficult to perform. The above problems are particularly apparent for large hydrolysis reactors having a volume of more than 500 cubic meters.

The above problems can be partially solved by providing a stirrer in the reactor, which stirs the liquid to flow to overcome the floating of the straw and simultaneously drives the straw mixed liquid to rotate in the reactor. The straw floating on the water surface is brought into the water by stirring and dispersed in the water, the drag force of the water flowing straw is utilized to be larger than or equal to buoyancy, and the drag force is related to factors such as density difference of the water and the straw, viscosity of the water, downward flow velocity of the water and the like, the flow velocity of the water is related to the pushing power of stirring and applying to water supply, and for the facultative hydrolysis reactor, the drag force is related to the lifting force generated to the surrounding water in the bubble rising process during aeration. The thrust action of the stirring on the water is related to the position and the rotating speed of the water and the materials in the water relative to the stirrer and the position of the wall of the container away from the stirrer. Therefore, the flow field of the stirring action of the stirrer on water is influenced by complex conditions, particularly for gas, liquid and solid three-phase fluids, the flow field distribution is extremely complex and is an uneven flow field. In such reactor designs, the particular reactor stirrer selection and parameter selection are essentially performed by empirical + experimental means.

The facultative hydrolysis reactor which is developed by the applicant and uses dry straws as a raw material is a gas (air), liquid (water) and solid (straws) three-phase fluid, the volume of the reactor is more than 500 cubic meters, the traditional stirring and mixing method can not meet the requirement, a straw shell layer is easily formed on the water surface, and a sediment layer is formed at the bottom.

In view of the above, there is a need to develop a new material mixing method for a new facultative hydrolysis reactor.

SUMMERY OF THE UTILITY MODEL

Researches find that the problem of insufficient stirring of materials in a large-volume facultative hydrolysis reactor cannot be solved by singly increasing the power of the stirrer or increasing the number of the stirrers, the particle size of straw particles in the reactor is small, the weight is light, the surface of the straw particles is hydrophobic, the straw particles are seriously layered with the liquid part of the facultative hydrolysis reactor, and the method is different from the state that the materials in a fermentation tank are hydrolyzed fully, become sticky and are not easy to separate from water, so that the stirring process of the fermentation tank can not achieve the expected effect even if the materials are directly moved.

After extensive analysis and exploration, we found that the vertical shaft vertical main stirrer and the obliquely inserted auxiliary stirrer are respectively arranged eccentrically. The vertical shaft vertical main stirrer provides a material circulation flow field which mainly comprises a vertical downward component force and is assisted by a horizontal component force, two to three layers of blades are arranged according to the depth of a liquid level, during normal operation, a flow field which rotates from the periphery to the axis is formed on the liquid level, the material rotates to flow to a stirring center area, the blades generate a downward flow field in the vertical direction of the stirring shaft, the straw material on the liquid level is sucked below the liquid level and continuously spirally flows downwards in an anticlockwise mode, and after the material reaches the lower area of the reactor, the material is diffused to the periphery under the action of reflection of the bottom surface and starts to flow upwards to form circulation; the inclined-insertion auxiliary stirrer can provide a vertical downward component force and a strong horizontal component force at the other side, and the installation angle of the inclined-insertion auxiliary stirrer is 30-50 degrees relative to the vertical direction, so that the inclined-insertion auxiliary stirrer can be adjusted according to the diameter or height of the reactor, and has the main function of bringing straw materials on the liquid surface below the liquid surface and preventing a scum layer from being generated in a region outside the action range of the main paddle. Meanwhile, the blades which are obliquely inserted and installed generate forward thrust in the horizontal direction, the direction of the forward thrust is consistent with that of a horizontal flow field generated by the main blades, and a strong flow field is generated in the hydrolysis tank together, so that scum and sediment layers are not formed in the reactor. Through the superposition of the two stirrers on the material driving force, a vortex is formed on the surface of the material in the container, disturbance is formed at the bottom, the material liquid flow at the center of the vertical flow field is promoted, and the material settled at the bottom can be stirred.

After the arrangement, a good liquid stirring flow field is formed in the facultative hydrolysis reactor, the problems of floating and crusting dry straws and sediment deposition after crushing and kneading in the straw facultative hydrolysis reactor are solved, and a good homogenizing effect is obtained.

Therefore, in order to solve the above problems in the prior art, the utility model provides a new large-scale facultative hydrolysis reactor, be applicable to the volume and be 500 cubic meters and above facultative hydrolysis reactor, the stirring effect reduces the energy consumption in making the reactor when more abundant even, improves stability, increase of service life. The following detailed description is made:

the utility model provides a large mixing stirring type facultative hydrolysis reactor, which comprises a body and a stirrer arranged in the body, wherein the body comprises a top part, a side wall and a bottom part; the stirrer comprises a stirring shaft and blades arranged on the stirring shaft, one end of the stirring shaft is fixed at the top of the body, and the other end of the stirring shaft is fixed at the bottom of the body;

the stirrer comprises a vertical shaft vertical main stirrer and an obliquely inserted auxiliary stirrer, and the two types of stirrers are arranged by deviating from the center of the body.

Preferably, in the large mixing stirring type facultative hydrolysis reactor, a feed port is arranged at the top of the body, and the feed port is close to the vertical main stirrer of the vertical shaft but not above the rotating range of the blades.

The feed inlet sets up in the position that is close to the perpendicular main agitator of vertical scroll, can avoid dry straw direct impact paddle to shorten the paddle life-span, can make the straw powder that falls into again just at the paddle edge, by slope rapidly in the feed liquid of pushing into the facultative hydrolysis reactor downwards.

Preferably, in the large mixing stirring type facultative hydrolysis reactor, the inclined auxiliary stirrer is arranged above and near the side wall, below and near the center of the body, and the stirring shaft is inclined from top to bottom along one side of the vertical shaft perpendicular to the rotation direction of the main stirrer.

For example, when the vertical shaft vertical main stirrer rotates anticlockwise, the material in the body flows anticlockwise along the side wall of the body in the horizontal direction, and the deflection of the stirring shaft of the oblique-insertion auxiliary stirrer in the horizontal direction is arranged in the anticlockwise flow direction.

Preferably, in the large mixing and stirring type facultative hydrolysis reactor, the bottom of the body is provided with an aeration pipe, which comprises an annular outer aeration pipe arranged between the two stirrers and the side wall, and a rectangular inner aeration pipe arranged between the two stirrers. The aeration pipe aerates the material liquid from the bottom, and the air flow impacts the material liquid to turn over, so that the stirring efficiency is further improved.

Preferably, in the large mixing and stirring type facultative hydrolysis reactor, the positions of the uppermost blades of the vertical shaft vertical main stirrer and the inclined insertion auxiliary stirrer are both located in a third area of the radius of the body close to the middle part or a half area of the radius of the body.

Preferably, in the large mixing stirring type facultative hydrolysis reactor, the total volume of the body is 500-1000 cubic meters, and the diameter is more than or equal to 10 meters.

Preferably, in the large mixing and stirring type facultative hydrolysis reactor, the size of the upper layer of the blades of the obliquely inserted stirrer is smaller than that of the lower layer of the blades. In the lower part of the facultative hydrolysis reactor, because of the high concentration of the feed liquid, large-diameter blades are needed to produce high-intensity circulation. The liquid level is constantly changed at the top of the facultative hydrolysis reactor, and the small-diameter paddle is used, so that the input straws are quickly mixed and are not easy to wind on the paddle.

Preferably, in the large mixing stirring type facultative hydrolysis reactor, the stirrer uses an alternating current variable frequency speed regulating motor, and can keep the stirring stability and reduce the energy consumption when the material concentration changes.

Preferably, in the large mixing and stirring type facultative hydrolysis reactor, the bottom of the body is provided with an aeration pipe, and the position of the aeration pipe is staggered with the position of the stirrer, so that external concurrent aeration and middle countercurrent aeration are formed.

Preferably, in the large mixing and stirring type facultative hydrolysis reactor, the blades of the vertical shaft vertical main stirrer and the inclined auxiliary stirrer rotate along the counterclockwise direction.

Compared with the prior art, the utility model discloses following beneficial effect has:

1. the method of mutually matching vertical stirring and inclined stirring and reasonably configuring the power of the motor is adopted, so that dry straws with strong hydrophobicity and far lower density than water are effectively blended into water, the biochemical reaction in the facultative hydrolysis reactor is ensured to be smoothly carried out, and the problem that the straws are easy to float upwards after being crushed is solved. The concentration of the feed liquid, namely the total solid content (TS), of the facultative hydrolysis reactor adopting the design scheme can reach 6-12%.

2. The vertical shaft vertical main stirrer and the obliquely inserted auxiliary stirrer are fixed at the position deviated from the center of the upper surface and the lower surface of the facultative hydrolysis reactor, and are matched with each other to form different flow field superposition effects, so that the stirring is more sufficient due to mutual influence.

3. The civil engineering investment is saved: after stirring in the reactor is more abundant, its volume receives the restriction of stirring effect to reduce, has increased effective volume, and the reactor volume can increase 500 ~ 1000 cubic meters, and after the effective volume increase, just can reduce reactor quantity under the unchangeable condition of productivity.

4. The equipment investment is saved: after the number of the reactors is reduced, the corresponding equipment and control systems are also reduced.

5. The operation cost is saved: the power of the stirrer is reasonably designed, and the energy consumption of operation is reduced. Through the design of the stirrer blades, blades with different diameters are matched for use, the large diameter is used for large circulation, and the small diameter blade is used for uniformly mixing new materials and plays a role respectively; the two types of stirrers are configured to form a flow field, so that the stirring effect is ensured, and the aeration is reused, so that the power consumption is reduced on the whole.

Drawings

FIG. 1 is a schematic top view of a large scale mixing and stirring type facultative hydrolysis reactor in example 1.

FIG. 2 is a schematic longitudinal sectional view of a large scale mixing and stirring type facultative hydrolysis reactor in example 1.

In the figure:

1. the vertical shaft vertical stirrer comprises a body, 2, a vertical shaft vertical main stirrer, 3, an obliquely inserted auxiliary stirrer, 4, a blade, 5, a straw blanking port, 6, an observation hole, 7, an access hole and 8, an aeration pipe.

Detailed Description

The technical solutions of the present invention will be explained and explained in detail with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement the present invention.

Example 1

Referring to fig. 1 and 2, a large scale mixing and stirring type facultative hydrolysis reactor according to an embodiment is designed in a plan view and a longitudinal sectional view, and includes a body 1 and a stirrer provided in the body 1.

The body 1 is a cylindrical hollow cubic structure and is formed by surrounding a circular bottom and a circular top by a side wall, the inner diameter is 12 m, the depth is 7 m, the effective water depth is 6.2 m, the total volume is 791 cubic meter, and the effective volume is 679 cubic meter.

The top of the body 1 is provided with a straw blanking port 5, an observation hole 6 and an access hole 7. The position of the straw blanking port 5 is close to the vertical shaft vertical to the main stirrer 2 but not above the rotating range of the blades 4, so that the straw blanking port is not easy to wind on the blades 4 to impact the blades 4 and the fallen straw can be quickly rolled into feed liquid by the blades 4. The observation hole 6 is preferably arranged at a position close to the straw blanking port, so that the straw blanking condition and the stirring effect can be observed conveniently.

The stirrer comprises two types, namely a vertical shaft vertical main stirrer 2 and an inclined insertion type auxiliary stirrer 3. The two stirrers are arranged diagonally, and the distance between the two stirrers and the side wall of the body 1 is more than 0.6 m. The stirrer cannot be too close to the side wall, which would result in insufficient stirring in the central position.

Referring to fig. 1, the top of the vertical shaft vertical main stirrer 2 and the obliquely inserted auxiliary stirrer 3 is located at about one-half of the radius of the body (i.e. the area 2-4 m away from the center and the side wall) on a straight line passing through the center of the body 1. The mixing shaft of the oblique-insertion auxiliary mixer 3 is obliquely arranged along the anticlockwise flow field direction of the vertical shaft vertical main mixer 2 from top to bottom. Specifically, the stirring shaft is deviated counterclockwise from the straight line in the horizontal direction at an angle of 40 to 60 degrees, and the stirring shaft is inclined 30 degrees in the vertical direction from the vertical direction. So that the rotating direction of the materials pushed by the vertical shaft is consistent with the rotating direction of the materials pushed by the vertical shaft vertical to the main stirrer.

Two kinds of agitator structures are unanimous basically to the perpendicular main agitator 2 of vertical scroll explains, including paddle 4, base and the footstock of installation on (mixing) shaft, the (mixing) shaft of agitator one end is passed through the base and is fixed in the body bottom, and the other end passes through the footstock and fixes at the body top, has increased the steadiness, can provide bigger stirring dynamics simultaneously. The paddle 4 is formed by coating an anti-seismic polymer (rubber or polyurethane) outside a steel core, so that the stability of the whole hydrolysis system during stirring is improved, and the service life is prolonged. An upper layer of blades 4 and a lower layer of blades 4 are arranged on the stirring shaft, wherein the size of the upper layer of blades of the obliquely inserted auxiliary stirrer 3 is smaller than that of the lower layer of blades.

The rotation directions of the inclined insertion type auxiliary stirrer 3 and the blade 4 of the vertical shaft vertical main stirrer 2 are both anticlockwise.

The bottom 12 of the body of the reactor is also fitted with an aerator pipe 8, comprising an annular outer aerator pipe located between the two agitators and the side wall, and an inner aerator pipe arranged in a rectangular shape between the two agitators. The position of the aeration pipe 8 is staggered with the stirrer, so that the stirring flow field is not influenced as much as possible, a mixed stirring flow field can be formed by aeration, and the bubbles are distributed as uniformly as possible.

Stirrer parameters:

item	Unit of	Obliquely inserted stirring device	Vertical shaft stirring
				Power of	KW	18.5	22
Electric current	A	36.5	40.7
				Rotational speed of the blades	rpm	38	54
Top blade diameter	mm	1500	2300
				Bottom blade diameter	mm	2650	2300
Circulating power (in water)	m3/h	16000	21000

The material mixing method (flow field distribution form) is introduced as follows: a vertical shaft deviated from the center of the reactor (body) is vertical to the main stirrer 2 to push the fluid to generate a flow field which mainly takes downward circulating flow and takes anticlockwise horizontal rotation as assistance. The oblique-insertion auxiliary stirrer 3 mainly forms a flow field which pushes fluid to rotate anticlockwise mainly and inclines materials downwards. Peripheral aeration pipe 8, the bubble rises and also can drive fluid on every side and produce ascending moving force, under the thrust and the aeration combined action of two agitators, the material produces ascending flow along the reactor lateral wall, simultaneously under the anticlockwise rotation effort that two agitators produced, the material is quick along reactor lateral wall anticlockwise rotation when rising to climb upwards along the lateral wall. Within the coverage range of the stirrer blades 4 and a certain distance from the periphery of the stirrer blades, the fluid is rapidly pushed downwards and forms rotation, and flows upwards along the side wall after reaching the bottom of the reactor and being restrained and reflected by the bottom and the side wall, so that circulation is formed. The vortex is formed downwards along the side wall and downwards along the middle part, the higher the rotating speed is, the larger the lifting force near the side wall is, the higher the vortex edge climbs along the side wall is, the lower the vortex middle part is, the higher the downward flow speed of the surface of the fluid is, the larger the dragging force on the light straws is, and the more difficult a shell layer is formed. At the same time, the bottom of the reactor is disturbed vigorously to prevent precipitation.

The conditions of the medium in the facultative hydrolysis reactor are as follows: the total solid content (TS) of the raw material dry corn straw is 80-85%, the particle size is less than 2cm, and the concentration (TS) of the feed liquid is 7-10% after the raw material dry corn straw is mixed with the backflow biogas slurry.

Stirring effect:

(1) the surface of the feed liquid of the reactor is free of a scum layer; the newly-fed straws are quickly mixed with the materials in the reactor and do not float above the liquid level;

(2) no obvious sedimentation occurs at the bottom of the fermentation tank (the concentration of the fermentation product discharged from the bottom sludge discharge pipe is not higher than 1.2 times of the average concentration of the tank body, for example, the bottom fermentation concentration is not higher than 10.8 percent when the average fermentation concentration of the tank body is 9 percent);

(3) the temperature distribution in the facultative hydrolysis reactor and the fermentation tank is uniform, the temperature difference is less than 0.3 ℃ (the temperature of the middle upper part in the actual measurement tank is 36 ℃, and the temperature of the middle lower part in the reactor is within 36 +/-0.3 ℃);

(4) TS in the facultative hydrolysis reactor and the fermentation tank is uniformly distributed, and the difference value is less than 5%;

(5) VFA (volatile fatty acid) in the facultative hydrolysis reactor and the fermentation tank is uniformly distributed, and the difference value is less than 5%;

(6) in the quality guarantee period, the equipment has no obvious abrasion, the coating has no shedding, and the abrasion of other materials is less than 5 percent of the thickness of the materials;

(7) the operation is continuous and stable under the condition of materials.

The invention concept is explained in detail herein using specific examples, and the above description of the embodiments is only used to help understand the core idea of the invention. It should be understood that any obvious modifications, equivalents and other improvements made by those skilled in the art without departing from the spirit of the present invention are intended to be included within the scope of the present invention.

Claims

1. A large mixing stirring type facultative hydrolysis reactor comprises a body and a stirrer arranged in the body, wherein the body comprises a top, a side wall and a bottom; the stirrer comprises a stirring shaft and blades arranged on the stirring shaft, one end of the stirring shaft is fixed at the top of the body, and the other end of the stirring shaft is fixed at the bottom of the body; the method is characterized in that:

2. The large scale mixing and stirring type facultative hydrolysis reactor according to claim 1, characterized in that: the top of the body is provided with a feed inlet, and the feed inlet is close to the vertical shaft and is vertical to the main stirrer but not above the rotating range of the blades.

3. A large scale mixing and stirring type facultative hydrolysis reactor according to claim 1 or 2, characterized in that: the oblique insertion type auxiliary stirrer is close to the side wall above the oblique insertion type auxiliary stirrer, is close to the center of the body below the oblique insertion type auxiliary stirrer, and inclines from top to bottom along one side of the rotating direction of the vertical shaft vertical to the main stirrer.

4. A large scale mixing and stirring type facultative hydrolysis reactor according to claim 1 or 2, characterized in that: the bottom of the body is provided with an aerator pipe which comprises an annular outer aerator pipe arranged between the two stirrers and the side wall and an inner aerator pipe arranged in a rectangular shape between the two stirrers.

5. A large scale mixing and stirring type facultative hydrolysis reactor according to claim 1 or 2, characterized in that: the positions of the blades on the uppermost layer of the vertical shaft vertical main stirrer and the inclined insertion auxiliary stirrer are both positioned in a third area of the radius of the body close to the middle part or a half area of the radius of the body.

6. A large scale mixing and stirring type facultative hydrolysis reactor according to claim 1 or 2, characterized in that: the total volume of the body is 500-1000 cubic meters, and the diameter is more than or equal to 10 meters.

7. A large scale mixing and stirring type facultative hydrolysis reactor according to claim 1 or 2, characterized in that: the size of the upper layer of blades of the obliquely inserted auxiliary stirrer is smaller than that of the lower layer of blades.

8. A large scale mixing and stirring type facultative hydrolysis reactor according to claim 1 or 2, characterized in that: the stirrer adopts an AC variable frequency speed regulating motor.

9. A large scale mixing and stirring type facultative hydrolysis reactor according to claim 1 or 2, characterized in that: the bottom of the body is provided with an aeration pipe, and the position of the aeration pipe is staggered with that of the stirrer to form external concurrent aeration and middle countercurrent aeration.

10. A large scale mixing and stirring type facultative hydrolysis reactor according to claim 1 or 2, characterized in that: the vertical shaft vertical main stirrer and the blades of the obliquely inserted auxiliary stirrer rotate along the anticlockwise direction.