CN112876014B - A method and reactor for low-speed hydrocyclone shearing and crushing of sludge to release carbon sources - Google Patents

Abstract

The invention relates to a method and a reactor for releasing carbon sources by shearing and crushing sludge with low-speed hydraulic cyclone. It is a low-energy consumption method for cracking municipal organic sludge. By setting an impeller at the bottom of the reactor for stirring, mechanical stirring and hydraulic , friction and centrifugal force work together to drive the small ball mill beads in the reactor to rotate and tumbling, thereby fully colliding, shearing and breaking the sludge, releasing the carbon source, and the sludge can be reduced, resourced and harmless. This method has simple equipment, is safe and reliable, has low operating energy consumption and has good shearing and crushing effects. The sludge carbon source is fully released, generally more than 40-50% of the sludge COD can be released, and the sludge reduction effect is significant. The treated sludge generally needs to undergo further biochemical treatment. The final secondary sludge has low organic matter content and low treatment and disposal costs.

Description

A method and reactor for low-speed hydrocyclone shearing and crushing of sludge to release carbon sources

Technical field

The invention belongs to the technical field of water environment protection, and specifically relates to a method and a reactor for shearing and crushing sludge with low speed hydrocyclone to release carbon sources.

Background technique

Insufficient carbon sources in municipal sewage treatment plants have become one of the constraints affecting sewage treatment efficiency. Currently, commonly used measures include developing new processes, adding additional carbon sources (such as methanol, etc.) or using carbon source substitute materials (such as pyrite). wait). With the continuous improvement of effluent quality requirements, the total nitrogen concentration of effluent has further decreased, and the demand for carbon sources has further increased. At the same time, after the sewage treatment of the sewage plant, there is often a large amount of residual sludge that needs to be treated and disposed, and the main component of the sludge is organic matter. However, due to the relatively stable nature of sludge, it cannot be directly used as a carbon source. Therefore, developing organic matter released from sludge to replace carbon sources has become one of the hot technologies in the field of water environment protection in recent years.

Domestic and foreign scholars have conducted extensive research on carbon sources released by sludge cracking. Cracking methods can be divided into physical methods, chemical methods, biological methods and combined treatment methods. The physical cracking methods for sludge mainly include ultrasonic waves, heat treatment, microwaves, optical radiation, mechanical ball milling, high-pressure injection, etc. The chemical method is to add various chemicals to the sludge, mainly strong oxidants (such as ozone, Fenton's reagent, ClO _2, etc.) and strong bases [NaOH, CaO, Ca(OH) ₂ , etc.]. Oxidants and strong alkali can destroy the floc structure of sludge, dissolve the cell wall (membrane) of microorganisms, dissolve the cell contents, and increase the SCOD concentration in sludge. The biological method uses enzyme preparations (such as lysozyme) or bacteria that can secrete extracellular enzymes (such as thermophiles) to hydrolyze the microbial cell walls in the sludge, causing the microbial cell walls to rupture and intracellular substances to dissolve. The energy consumption of drum ball mill for crushing sludge is relatively low, but the equipment structure is complex and the equipment cost is high.

Contents of the invention

The purpose of the present invention is to solve the shortcomings of the prior art by constructing a certain reactor structure and driving the sewage/sludge/ball mill beads at the bottom of the reactor at a low flow rate under the joint action of mechanical force and hydraulic force. Continuous mixing, grinding and shearing are used to break up the sludge cells. After the cells are fully broken, on the one hand, the contents of the sludge cells are released, which can release some small molecular organic matter. Most of these organic matter can be directly used as the carbon source for the sewage denitrification process; on the other hand, the macromolecules that make up the cell wall and cell membrane components are also released. It can be fully broken, sheared and ground, and can also be fragmented into smaller particulate organic matter, which is conducive to subsequent further processing and deep release of carbon sources. The energy consumption of the method of the present invention is lower than that of the traditional mechanical ball milling method; at the same time, it has the advantage of simple equipment. If combined with the biological method, the carbon source can be fully recycled.

The present invention achieves the above objects through the following technical solutions:

A method of low-speed hydrocyclone shearing and crushing sludge to release carbon sources. The sewage and sludge are introduced into the reactor, and the sludge is mixed with ball mill beads of different specifications according to the proportion of cyclone, and a lower temperature is controlled in the reactor. The bottom swirl speed causes different specifications of ball mill beads to collide and grind with each other during the rotation process, continuously shearing the sludge, breaking the sludge cells, and releasing the carbon source.

As a further optimization solution of the present invention, during the mixing and swirling process of sewage, sludge and ball mill beads in the reactor, the sludge is continuously sheared and broken, the intracellular contents are released, the cell walls and cell membranes are broken, and then the Coagulant is introduced into the reactor, and the crushed sludge fragments are mixed with the coagulant, flocculated and precipitated, and the precipitated sludge fragments are further crushed by ball mill beads. The carbon source is discharged from the reactor following the water flow, and is treated using anaerobic biological methods. , to fully release the carbon source. For the crushed sludge fragments, especially the colloidal-sized particles after crushing (the size is about 0.05 μm or more), due to their relatively small density, it is difficult to settle back to the bottom area, so coagulant can be added to promote Its cohesion. For smaller sludge fragments (the particle size is about 0.02 μm or less), because they have been fully broken, they flow out of the reactor with the water, so that the sludge cells can obtain a better breaking effect.

As a further optimization solution of the present invention, the ball milling beads are glass beads, zirconium beads or steel balls, the shape of the ball milling beads is spherical, and the average diameter of the ball milling beads is in the range of 0.6 to 4.5 mm.

The size of the ball mill beads must be appropriate. The size of ball milling beads cannot be too large or too small. The maximum size of ball milling beads is 3.5~4.5mm to meet the requirements, and the minimum size of ball milling beads is 0.6~1.0mm. The greater the density of ball mill beads, the smaller the optimal size. The specific optimal size is also related to the properties of the sludge and should be determined through experiments.

The number of ball milling beads also needs to be appropriate. During actual operation, it was found in small-scale experiments that the ratio of sludge volume (referring to the volume of wet sludge entering the reactor, non-dry sludge volume) and the volume of ball mill beads is around 2 to 3, which is ideal. The actual operation process can be determined according to the specific process. Parameters can be adjusted flexibly in real time.

As a further optimization solution of the present invention, the maximum linear velocity of the edge water flow at the bottom of the reactor is 1.2~1.8m/s. If the velocity is too high, the energy consumption will be high; but if the velocity is too low, the shearing effect will be poor. The response time required is also relatively long.

As a further optimization solution of the present invention, the reactor has two to three stages, the swirl speed gradually decreases from the first stage reactor to the last stage reactor, and the particle size of the ball mill beads gradually decreases. When multi-stage is used, the multi-stage reactor operates intermittently, and iron salt is added to the reactor during intermittent operation. Among them, the first-stage reactor has a fast swirl speed and a large ball milling bead size, which is mainly used for preliminary crushing of sludge. The second-stage and third-stage reactors have a slow swirling speed, small ball milling bead size, and are used to fully crush the sludge. Grinding sludge. The reactor adopts intermittent operation. Multiple groups of intermittent operation are conducive to the recovery of carbon sources from broken sludge, and the addition of iron salts basically eliminates the release of phosphorus.

As a further optimization solution of the present invention, the cross-section of the reactor is cylindrical or approximately cylindrical. The cross-sectional shape of the reactor, especially the cross-sectional shape of the bottom area, can be further optimized according to the size of the reactor, the properties of the sludge, and the properties of the ball mill beads. It is inverted conical, V-shaped or inverted parabolic shape, etc. The upper diameter of the reactor can be larger than the bottom diameter; the effective vertical height of the reactor should be greater than 4 to 5m, and the top sedimentation area should be basically not affected by the bottom water flow. And ensure that the rotation of the impeller at the bottom can push the bottom water flow to maintain a certain speed. At the same time, the rotation speed of the water flow in the upper part of the reactor should be lower, and the flow speed gradually decreases from bottom to top, which exactly meets the hydraulic requirements of coagulation.

A reactor for a method of shearing and crushing sludge with low speed hydrocyclone to release carbon source, including a tank body, a mud inlet pipe, a stirring device, a sedimentation device and a dosing pipe;

The bottom of the inner cavity of the pool is a shearing zone. A stirring device is arranged in the center of the shearing zone. The ball mill beads are located in this zone. The mud inlet pipe leads from the bottom of the pool body to the center of the shearing zone and is higher than the bottom of the pool. The mud inlet pipe is used to input the shearing zone. For sludge and sewage, the stirring device drives the sewage, sludge and ball mill beads to rotate, and the rotating ball mill beads shear the sludge;

The top of the inner chamber of the pool is a sedimentation area, and a sedimentation device is arranged. The sedimentation device isolates the centrifugal force generated by the cyclone. Larger sludge fragments and flocculated sludge fragments settle in this area and can be sheared back to the bottom. district;

The buffer zone is between the shear zone and the sedimentation zone, and the outer area in the middle and upper part of the reactor is the flocculation zone. The flow rate of the water flow gradually decreases from bottom to top. The side wall of the pool corresponding to the flocculation zone is connected to a dosing pipe. The medicine tube is passed into the coagulant;

A drainage weir is fixedly connected to the top of the pool, and the bottom end of the drainage weir is connected to the top of the pool to form a water outlet area for the discharge of carbon sources and water flow.

As a further optimization solution of the present invention, the stirring device includes an impeller, a drag plate, a central connecting rod, and a stirring motor. The impeller is arranged at the center of the reactor cavity near the bottom. The top of the impeller is connected to the stirring motor through the central connecting rod. The stirring motor is connected to the motor shaft. The stirring motor is located above the pool body and above the water surface. A partition is fixed at the bottom of the stirring motor. The drag plate is fixed to the bottom of each impeller blade through an oblique connecting rod. The drag plate is connected to the impeller. The layout direction is the same, and several holes are provided on the drag plate. The drag plate is set in an arc shape; the drag plate is arranged on the lower part of the impeller as needed. The purpose of setting the drag plate is to avoid the ball milling beads at the bottom from becoming hardened (especially for a long time). When the operation is stopped), the drag plate presses on the mixture of ball mill beads and sludge under the action of its own gravity. During the rotation process, the drag plate pushes the water, ball mill beads and sludge to move together. Since there are There are a large number of holes, so the role of the drag plate is equivalent to stirring. Under the condition of hydraulic rotation, the ball mill beads and sludge are constantly rotating, tossing and colliding due to the combined effects of gravity, thrust, centrifugal force and friction. Due to the different sizes of ball mill beads, , the difference in running speed is obvious, so the ball mill beads can fully shear and crush the sludge.

A mud flushing pipe is connected to the corresponding pool body on one side of the bottom of the shear zone. The water inlet end of the mud flushing pipe is connected to the water source through a pressure pump. When ball mill beads accumulate seriously in the center or around the pool, the pressure pump can be started. , the high-speed water flow in the mud flushing pipe blows the ball milling beads, and the ball milling beads can be pushed into the dragging area of the dragging plate. After taking this measure, it can ensure that the distribution of ball mill beads on the bottom of the pool has a certain uniformity. In particular, if the reactor is stopped for a period of time, the unfavorable phenomenon of hardening/adhesion of ball mill beads and sludge may occur.

As a further optimization solution of the present invention, the blades of the impeller are perpendicular or approximately perpendicular to the water surface. The vertical arrangement of the blades can avoid driving the water flow from forming a significant longitudinal circulation. Under the stirring action of the impeller, the water flow at the bottom of the reactor is pushed to rotate in the horizontal direction. . Considering the kinematic viscosity of water and the difference in water flow velocity between the bottom and the upper part of the reactor, it is better that the vertical distance between the upper edge of the impeller and the sedimentation zone is greater than 1.5 times the diameter of the reactor, and the greater the edge linear velocity, the greater the distance;

The shape of the impeller blades is rectangular, gourd-shaped or pipa-shaped, and the diameter of the impeller is slightly smaller than the diameter of the reactor, so that the rotation linear speed of the impeller edge is close to the edge linear speed of the water flow, and the gap between the impeller and the inner wall of the pool is greater than the two maximum The sum of the ball milling bead diameters prevents the impeller from blocking the ball milling beads. In addition, the distance between the impeller and the bottom of the pool should not be too small, otherwise it will be difficult to start after a long period of stoppage;

The area of the impeller at the connection between the impeller and the central connecting rod gradually decreases, or a certain distance is maintained between the impeller and the central connecting rod. When the distance between the impeller and the central connecting rod is maintained, a cross bar is passed between the impeller and the central connecting rod. Fixed connection. It can avoid the excessive negative pressure formed when the impeller rotates, causing the sewage in the upper part of the suction reactor to form a strong longitudinal circulation (low pressure is formed in the center due to centrifugal force). Even so, the formation of a certain intensity of longitudinal circulation is still inevitable, but considering the circulation The range is not large, and the water flow in the center is from top to bottom. The circulation intensity is not large and has no adverse impact on the sludge settling area.

As a further optimization solution of the present invention, the sedimentation device includes a plurality of vertically arranged baffles. The plurality of baffles are distributed in an annular array with the central connecting rod as the center of the circle. One end of the baffles close to the inner wall of the pool is fixedly connected to the pool body. At the top of the reactor is the sedimentation zone. Since it is far away from the impeller, the rotation speed of the water flow is greatly reduced, and a vertical baffle is set up in the sedimentation zone. The centrifugal force is completely hindered, so the crushed residual fine-grained sludge can precipitation.

The basic principle of the present invention is that even if sludge cells die, it is difficult to use them directly as a carbon source. If the sludge particles are small and broken by physical methods such as pressure, the energy consumption will be huge. The specific heat capacity of the sludge is high. If it is cracked by heating, the energy consumption will be very large and the economy will be poor. The mechanical ball milling method is used for high-speed shearing. Although the crushing effect is good, the Energy consumption is also very large. The stiffness and hardness of sludge cells and the bacterial jelly they form are very small, and they are easily broken under the action of grinding and shearing. Therefore, ball milling beads with small spherical particles can be used as the crushing medium. Under the combined action of hydraulic and mechanical forces, even if Efficient sludge crushing can also be achieved under low flow rates.

The beneficial effects of the present invention are:

1) The operating energy consumption of the present invention is low; water/mud/bead mixing, low flow rate can maintain the shearing and grinding effects, the energy consumption of this method is only equivalent to several times the energy consumption of the operation of a water treatment reactor, and is compared with the existing Compared with cracking methods such as ultrasonic, heating, ball milling and other methods, energy consumption can be saved by more than 50 to 80%;

2) The organic matter released by this method can be returned to the biological treatment process, the carbon source is fully utilized, and the resource utilization of sludge is fully realized;

3) The equipment of the present invention is simple, easy to process, safe and reliable;

4) Using this method, the secondary residual sludge is fully reduced, and the weight is reduced by more than 50% compared with the original residual sludge;

5) The secondary residual sludge using this method has low organic matter content and is easy to be further disposed and utilized;

6) When this method is used for secondary residual sludge dehydration, less chemicals are consumed and the treatment cost is low;

7) In the sludge cracking process using this method, because iron salt is added as an auxiliary agent, there is basically no release of phosphorus;

8) The process method of the present invention is suitable for the treatment and disposal of residual sludge in municipal sewage plants of various sizes.

Description of the drawings

Figure 1 is an overall cross-sectional view of the reactor of the present invention;

Figure 2 is a top view of the reactor of the present invention;

In the picture: 1 pool body; 11 shear zone; 12 sedimentation zone; 13 buffer zone; 14 flocculation zone; 15 water outlet zone; 2 mud inlet pipe; 3 stirring device; 31 impeller; 32 drag plate; 33 central connecting rod; 34 stirring motor; 4 sedimentation device; 41 baffle; 5 dosing pipe; 6 mud flushing pipe; 7 drainage weir.

Detailed ways

The embodiments of the present invention are described below. It should be understood that the embodiments described here are only used to illustrate and explain the present invention, and are not used to limit the flow, structure, parameters, etc. of the process of the present invention; the specific parameters given in the embodiments are These are merely examples for illustrating the present invention and are not necessarily parameters that must be adopted. Small particle spherical or nearly spherical materials are used as grinding means, and mechanical force is used to push the water flow to form a cyclone (including the use of long corridor shapes to form circulation), so that the water/beads/mud can continuously roll and churn in the reactor to break the dirt. Clay, all belong to the protection scope of the present invention.

A method for releasing carbon sources by shearing and crushing sludge with low-speed hydrocyclone. The steps include: passing sewage and sludge into a reactor with a cylindrical or approximately cylindrical cross-section, and swirling the sludge with ball mill beads of different specifications. Mixing, during the rotation process, ball mill beads of different sizes collide and grind with each other, continuously shearing the sludge, breaking the sludge cells, and releasing the carbon source.

In order to fully and efficiently obtain carbon sources, during the sludge crushing process, coagulant is introduced into the reactor. The crushed sludge fragments are mixed with the coagulant, flocculated and precipitated, and the precipitated sludge fragments are further crushed by ball milling beads. , the carbon source is discharged from the reactor following the water flow, and is treated using anaerobic biological methods to fully release the carbon source.

It should be noted that the sludge is concentrated sludge. The sludge concentration entering the reactor is greater than 25000 mg/L, and the sludge concentration should be increased as much as possible within a technically reasonable range. In order to reduce the amount of secondary residual sludge, it is also In order to cooperate with the operation of this reactor, the sludge is obtained through the original sewage treatment process. The grit chamber parameters of the original sewage treatment process should adopt a longer HRT (Hydraulic Retention Time, also called hydraulic retention time) and a lower flow rate ( rotation speed) to improve the removal rate of fine sand particles in raw sewage, the reactor can use a longer HRT.

Among them, the ball milling beads are glass beads, zirconium beads or steel balls, the shape of the ball milling beads is spherical, and the average diameter of the ball milling beads is in the range of 0.6 to 4.5 mm.

The size of the ball milling beads cannot be too large, otherwise the required water flow rate will be too high and the energy consumption will be too high. Moreover, if the size of the ball milling beads is too large, the contact surface with the sludge during shearing will be small, and a longer reaction time will be required to grind the ball milling beads. The sludge is fully broken up. According to the data analysis of laboratory test results, the maximum size of ball milling beads is 3.5~4.5mm to meet the requirements. The size of the ball milling beads cannot be too small. The shearing effect of the ball milling beads on the cells will also be reduced. Instead, a higher flow rate is required to ensure the shearing effect. According to the data analysis of laboratory test results, the minimum size of ball milling beads is 0.6~1.0mm. The optimal size of ball milling beads is related to the operating speed and ball milling bead density, and the optimal speed is related to the sludge characteristics. Therefore, the optimal size should be determined based on the sludge characteristics and the best parameters obtained through field experiments.

The number of ball milling beads is mainly considered during operation. The ratio of sludge to ball milling beads must be appropriate. Whether there is too much sludge or too many ball milling beads will affect the effect of the reactor. Theoretically, the greater the amount of ball mill beads, the better the shearing effect. However, due to less mud, the processing capacity is lower and the energy consumption is higher. During actual operation, it was found in small-scale experiments that the ratio of sludge volume (referring to the volume of wet sludge entering the reactor, non-dry sludge volume) and the volume of ball mill beads is around 2 to 3, which is ideal. The actual operation process can be determined according to the specific process. Parameters can be adjusted flexibly in real time. Since the number (weight) of ball milling beads is basically a fixed value during operation, the flow and concentration of sludge entering the reactor can be adjusted to achieve the optimal ratio of sludge to ball milling beads. The thickness of the ball milling beads at the bottom of the reactor in a static state (that is, the total amount of ball milling beads in the reactor) is related to many factors such as the weight, rotation speed and shape of the drag plate 32, and is also related to the ball milling bead ratio, and the ball milling beads are The amount should match the specific parameters of the drag plate 32, so the specific parameters of different devices should be determined through experiments to determine the best parameters. Considering that the bottom layer of ball milling beads is in an almost stationary state under working conditions and does not affect the operation of the reactor, an appropriate amount of ball milling beads is allowed to be too high. The thickness of the ball milling bead layer in the bottom shear working area when it is in the working state (that is, the thickness in the disturbed state, not the thickness in the static state) should be consistent or nearly consistent with the height of the impeller 31.

In addition, the ball milling beads can be replaced or partially replaced with wear-resistant sand. The lower part of the pool wall and the place where the pool bottom is in contact with the friction material should be made of reinforced wear-resistant materials. Ball milling beads with too small particle size should be sorted out through regular washing. , and replenish ball milling beads regularly.

The driving source of the reactor driving the mixed cyclone of sewage, sludge and ball milling beads is the impeller 31. The reactor drives the rotation of the ball milling beads due to the combined effect of the hydrocyclone and the stirring of the impeller 31. By adjusting the speed of the impeller 31, the edge of the bottom of the reactor is controlled. Linear speed of water flow, this speed is required to maintain the ball milling beads to be able to rotate and have sufficient shear force. The maximum edge linear speed can be controlled at 1.2~1.8m/s. If the speed is too high, the energy consumption will be high; however, If the speed is too low, the shearing effect will be poor and the reaction time required will be too long.

From the perspective of reactor efficiency, during actual operation, the reactor can be divided into two to three stages according to needs. From the first stage reactor to the last stage reactor, the swirl speed gradually decreases, and the ball milling bead particle size gradually decreases. The intermittent operation of the first-stage reactor is beneficial to the recovery of carbon sources from broken sludge, and when iron salt is added to the reactor during intermittent operation, there is basically no release of phosphorus.

The cross-sectional shape of the reactor, especially the cross-sectional shape of the bottom area, can be further optimized into an inverted cone, V-shape, or inverted parabola shape according to the size of the reactor, the properties of the sludge, and the properties of the ball mill beads. The upper diameter of the reactor can be larger than the bottom diameter. . The effective vertical height of the reactor should be greater than 4 to 5 m, and the top sedimentation zone 12 should be basically not affected by the bottom water flow.

For intermittent operation, the reactor structure is not limited by the above description. The reactor only needs to be circular. The process operates according to stirring-precipitation-sludge discharge. Multiple groups of intermittent operation are beneficial to the carbon source recovery of broken sludge.

As shown in Figure 1-2, a reactor for low-speed hydrocyclone shearing and crushing of sludge to release carbon sources includes a tank body 1, a mud inlet pipe 2, a stirring device 3, a sedimentation device 4 and a dosing pipe 5;

The bottom of the inner cavity of the pool body 1 is the shearing zone 11. A stirring device 3 is arranged in the center of the shearing zone 11. The ball mill beads are located in this zone. The mud inlet pipe 2 leads from the bottom of the pool body 1 to the center of the shearing zone 11 and is higher than At the bottom of the pool, the stirring device 3 drives the sewage, sludge, and ball mill beads to rotate, and the rotating ball mill beads shear the sludge;

The top of the inner cavity of the pool 1 is a sedimentation area 12, and a sedimentation device 4 is arranged. The sedimentation device 4 isolates the centrifugal force generated by the cyclone. Larger sludge fragments and flocculated sludge fragments settle in this area, which can Return to bottom clipping area 11;

The buffer zone 13 is between the shear zone 11 and the sedimentation zone 12, and the outer area in the middle and upper part of the reactor is the flocculation zone 14. The flow rate of the water flow gradually decreases from bottom to top. The flocculation zone 14 is connected to the side wall of the pool 1 corresponding to Dosing pipe 5, through which the coagulant is introduced;

A drainage weir 7 is fixedly connected to the top of the pool body 1, and the bottom end of the drainage weir 7 is connected to the top of the pool body 1 to form a water outlet area 15.

The stirring device 3 includes an impeller 31, a drag plate 32, a central connecting rod 33, and a stirring motor 34. The impeller 31 is arranged at the center of the reactor cavity near the bottom. The top of the impeller 31 is connected to the stirring motor through the central connecting rod 33. 34 is connected to the motor shaft. The stirring motor 34 is located above the pool body 1 and above the water surface. A partition is fixed at the bottom of the stirring motor 34. The drag plate 32 is fixed to the bottom of the blade of each impeller 31 through an oblique connecting rod. The drag plate 32 is arranged in the same direction as the impeller 31. Several holes are provided on the drag plate 32, and the drag plate 32 is arranged in an arc shape;

A mud flushing pipe 6 is connected to the pool body 1 corresponding to the bottom side of the shear zone 11, and the water inlet end of the mud flushing pipe 6 is connected to the water source through a pressure pump.

The blades of the impeller 31 are vertical or approximately perpendicular to the water surface, and the vertical distance between the upper edge of the impeller 31 and the sedimentation zone 12 is greater than 1.5 times the diameter of the reactor. The shape of the blades of the impeller 31 is rectangular, gourd-shaped or pipa-shaped. The impeller 31 The diameter is smaller than the diameter of the reactor, and the gap between the impeller 31 and the inner wall of the pool body 1 is greater than the sum of the diameters of the two largest ball milling beads. The area of the impeller 31 at the connection between the impeller 31 and the central connecting rod 33 gradually decreases, or the impeller 31 is connected to the center. A certain distance is maintained between the rods 33. When the distance between the impeller 31 and the central connecting rod 33 is maintained, the impeller 31 and the central connecting rod 33 are fixedly connected through a cross bar.

The sedimentation device 4 includes a plurality of vertical baffles 41 , which are distributed in an annular array with the central connecting rod 33 as the center. One end of the baffles 41 close to the inner wall of the pool 1 is fixedly connected to the pool 1 .

The operation process of the reactor of the present invention is:

The sludge enters the reactor from the mud inlet pipe 2 in the center of the bottom. In order to prevent the ball mill beads from falling into the mud inlet pipe 2 during the mixing process, the elevation of the mud inlet pipe 2 needs to be higher than the bottom of the tank; after the sludge enters, it immediately enters under the action of centrifugal force. Shear zone 11, because the water flow/sludge/ball mill beads are mixed together, under the combined action of mechanical force, centrifugal force, gravity, and the disturbance friction of the water flow, the ball mill beads and sludge will continue to rotate and tumble in the bottom area of the reactor , the ball mill beads sandwich the sludge and continuously collide, shear and grind, and the cells of the sludge are broken.

After the sludge is fully sheared, it enters the upper reaction flocculation zone 14 and sedimentation zone 12. The insufficiently broken sludge and flocculated sludge particles can return to the shearing zone 11 through the buffer zone 13, and the fully broken sludge flows out. reactor. specific:

The broken sludge fragments can follow the water flow from the side wall of the reactor and enter the sedimentation zone 12. At this time, under the action of the hydrocyclone, the side wall still maintains a certain horizontal flow rate (there is also a vertical flow rate, but it is very small). , add coagulant at the side wall. Since the flow rate around the pool wall gradually decreases from bottom to top, which just meets the hydraulic requirements of coagulation, this is the reactive flocculation zone 14. The sludge fragments with colloidal particle size can return to the shear zone 11 after flocculation and be further broken. After entering the sedimentation zone 12, the water flow velocity gradually decreases, and larger sludge fragments can condense. Since the water flow in the middle of the reactor is similar to a vertical flow sedimentation tank, and the sedimentation speed is low (calculated based on the water depth of the sedimentation zone 12 being 2m and the hydraulic retention time of 1h, the sedimentation rate is 1 hour). The speed is about 0.5~0.6mm/s), and the flocculated sludge can easily slide to the buffer zone 13 in the center and further slide back to the shear zone 11. Due to the layout of this reactor, the edge side wall water flow has a slight upward flow velocity under the impeller 31, so the speed direction of the circulation of the water flow in the center of the reactor is downward (the vertical circulation velocity is very small, the circulation velocity is small Depends on the rotation speed of the impeller 31), so even if the coagulation effect is poor, the granular sludge will easily slide back to the shear zone 11.

When the stirring device 3 is used, the stirring motor 34 drives the impeller 31 to rotate in the horizontal direction through the central connecting rod 33. The rotation linear speed of the edge of the impeller 31 is close to the edge linear speed of the water flow, so the diameter of the impeller 31 can be slightly smaller than the diameter of the reactor. When 31 rotates, the drag plate 32 is driven to rotate. The drag plate 32 presses on the mixture of ball mill beads and sludge under the action of its own gravity. During the rotation, the drag plate 32 pushes the water, ball mill beads and sludge together. Movement, because there are a large number of holes on the drag plate 32, the role of the drag plate 32 is equivalent to stirring. Under the conditions of hydraulic rotation, the ball mill beads and sludge work together with gravity, thrust, centrifugal force and friction to continuously rotate, tumbling and collide. Since the ball mill beads are of different sizes, their running speeds are significantly different, so the ball mill beads can be fully sheared. Break up sludge.

Due to the inconsistent size of the ball milling beads, when the bottom of the pool has a certain slope, the ball milling beads may gradually gather in the center of the pool bottom during operation; when the pool bottom is level, the ball milling beads may gather around the bottom of the pool, and the ball milling beads accumulate at the bottom of the pool. It will also cause a decrease in efficiency, so appropriate measures need to be taken to avoid this situation. Measures include:

(1) Improve design accuracy. The distance between the impeller 31 and the bottom of the pool is controlled within the optimal range;

(2) Use an impeller 31 that can adjust the rotation speed. Increasing the rotation speed of the impeller 31 increases the centrifugal force and the ball mill beads can gradually move away from the center position; vice versa;

(3) Set the angle of the drag plate 32 reasonably so that the drag plate 32 is not perpendicular to the center along the diameter direction, but is arc-shaped;

(4) Adjust the slope of the pool bottom. When the accumulation of ball milling beads in the center or around the pool is severe and the above mentioned methods cannot disperse the ball milling beads, the mud flushing pipe 6 will be started. The high speed water flow in the mud flushing pipe 6 will blow the ball milling beads and push the ball milling beads into the drag plate 32 Drag area. After taking this measure, it can ensure that the distribution of ball mill beads on the bottom of the pool has a certain uniformity. In particular, if the reactor is stopped for a period of time, the unfavorable phenomenon of hardening/adhesion of ball mill beads and sludge may occur.

Example 1

The operation process of the continuous flow reactor is as follows:

Municipal sludge first needs to be concentrated, either by gravity or mechanical concentration. The MLSS of concentrated sludge reaches more than 25000mg/L.

The sludge enters from the bottom of the reactor and immediately enters the shear zone 11 under the action of the impeller 31. As shearing proceeds, sludge particles and cells are broken and gradually fragmented into smaller particles. Small particles will flow out of the shear zone 11 with the water flow. When the particles are not particularly small, they will return to the shear zone 11 in the sedimentation zone 12 under the action of gravity. When the particles are small, they enter the reactive flocculation zone 14, and chemicals are added to the reactive flocculation zone 14, but they can still flow back to the shear zone 11. When the particles are extremely small and the flocculation reaction in the reactor is not enough to agglomerate into large particles, the organic matter particles will flow out of the reactor.

A drainage weir 7 is set at the top of the reactor, and the fine-grained sludge that cannot settle flows out of the reactor through the water outlet area 15 along with the sewage (turbid liquid).

The turbid liquid discharged from the system contains high concentrations of organic matter fine particles SS and should be further processed and used as a carbon source.

Example 2

The operation process of the intermittent operation reactor is as follows:

Municipal sludge first needs to be concentrated, either by gravity or mechanical concentration. The MLSS of concentrated sludge reaches more than 25000mg/L.

Reactors operating in batch mode do not need to consider partitions, all are shear zones 11, and the reactor can simply adopt a cylindrical shape. The depth of the reactor is small, and the effective depth of the reactor water during operation is appropriately greater than the height of the ball mill beads after expansion. This ensures that all sludge is in contact with the ball mill beads during shearing.

The sludge is put into the reactor at one time. After the shearing stops, the ball mill beads settle at the bottom. The turbid liquid formed after the sludge is broken is discharged from the reactor, and the drainage liquid is also discharged from the bottom. For example, to control the treatment effect of process phosphorus, iron salt should also be added to the reactor during intermittent operation.

The turbid liquid discharged from the system contains high concentrations of organic matter fine particles SS and should be further processed and used as a carbon source.

The above-mentioned embodiments only express several implementation modes of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the patent scope of the present invention. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims (7)

1. A method for releasing carbon source by shearing and crushing sludge with low-speed hydrocyclone, characterized by: including a reactor: The reactor includes a tank body, a mud inlet pipe, a stirring device, a sedimentation device and a dosing pipe; The bottom of the inner cavity of the pool is a shearing area. A stirring device is arranged in the center of the shearing area. Ball mill beads are provided in the shearing area. The mud inlet pipe leads from the bottom of the pool body to the center of the shearing area and is higher than the bottom of the pool. Through the inlet The mud pipe inputs sludge and sewage, and the stirring device drives the sewage, sludge and ball mill beads to rotate; The top of the inner chamber of the pool is a sedimentation area, with a sedimentation device arranged to isolate the centrifugal force generated by the swirling flow; The buffer zone is between the shear zone and the sedimentation zone, and the outer area in the middle and upper part of the reactor is the flocculation zone. The side wall of the tank corresponding to the flocculation zone is connected to a dosing pipe, and the coagulant is introduced through the dosing pipe; A drainage weir is fixedly connected to the top of the pool body, and the bottom end of the drainage weir is connected to the top of the pool body to form a water outlet area; The stirring device includes an impeller, a drag plate, a central connecting rod, and a stirring motor. The impeller is arranged at the center of the reactor cavity near the bottom. The top of the impeller is connected to the motor shaft of the stirring motor through the central connecting rod. The stirring motor is located at Above the pool body and above the water surface, a partition is fixed at the bottom of the stirring motor. The drag plate is fixed to the bottom of the impeller blade through an oblique connecting rod. The drag plate is arranged in the same direction as the impeller. The drag plate is provided with Several holes, the drag plate is set in an arc shape; The blades of the impeller are perpendicular or approximately perpendicular to the water surface, and the vertical distance between the upper edge of the impeller and the sedimentation zone is greater than 1.5 times the diameter of the reactor, the diameter of the impeller is less than the diameter of the reactor, and the gap between the impeller and the inner wall of the pool is greater than the two largest ball mill beads. sum of diameters; The sedimentation device includes a plurality of vertically arranged baffles. The plurality of baffles are distributed in an annular array with the central connecting rod as the center of the circle. One end of the baffles close to the inner wall of the pool is fixedly connected to the pool body; The steps of the method include: after concentration, the sludge whose MLSS reaches more than 25,000 mg/L enters the reactor from the mud inlet pipe in the center of the bottom. After entering, the sludge immediately enters the shear zone under the action of the centrifugal force generated by the stirring device, The sludge is swirled and mixed with ball milling beads of different specifications. During the rotation process, the ball milling beads of different specifications collide and grind with each other, continuously shearing the sludge, breaking the sludge cells, and releasing the carbon source; among them, the mixing device stirs When the stirring motor drives the impeller to rotate in the horizontal direction through the central connecting rod, when the impeller rotates, it drives the drag plate to rotate. The drag plate presses on the mixture of ball mill beads and sludge under the action of its own gravity. During the rotation process, The drag plate pushes water, ball mill beads and sludge to move together; After the sludge is fully sheared, it enters the upper flocculation zone and sedimentation zone, and the coagulant is introduced to the middle and upper edge of the reactor. The crushed sludge fragments are mixed with the coagulant, and flocculate and settle in the center of the upper part of the reactor. The sludge fragments are further broken by the ball mill beads. The fully broken sludge releases the carbon source and is discharged from the reactor with the water flow. The insufficiently broken sludge and flocculated sludge particles can return to the shear zone through the buffer zone for further further treatment. broken; The average diameter of the ball milling beads of different specifications is in the range of 0.6~4.5mm, the ratio of sludge volume to ball milling bead volume is 2~3, and the linear velocity of the edge water flow at the bottom of the reactor is 1.2~1.8m/s, so The effective vertical height of the reactor is greater than 4m. 2. A method for releasing carbon sources by shearing and crushing sludge with low-speed hydrocyclone according to claim 1, characterized in that: the carbon sources are discharged from the reactor following the water flow, and are further processed by anaerobic biological methods. 3. A method of low-speed hydrocyclone shearing and crushing sludge to release carbon sources according to claim 1, characterized in that: the ball milling beads are glass beads, zirconium beads or steel beads, and the shape of the ball milling beads is spherical. 4. A method of low-speed hydrocyclone shearing and crushing sludge to release carbon sources according to claim 1, characterized in that: the reactor takes two to three stages, from the first stage reactor to the last stage. The swirl speed of the stage reactor gradually decreases, and the particle size of the ball mill beads gradually decreases; the reactor adopts a multi-stage reactor intermittent operation mode, and iron salt is added to the reactor during intermittent operation. 5. A method of low-speed hydrocyclone shearing and crushing sludge to release carbon sources according to claim 1, characterized in that: the cross-section of the reactor is cylindrical or approximately cylindrical, and the cross-sectional shape of the reactor is Inverted cone, V-shaped or inverted parabola, the diameter of the upper part of the reactor is larger than the diameter of the bottom. 6. A method for releasing carbon sources by shearing and crushing sludge with low-speed hydraulic cyclone according to claim 1, characterized in that: a mud flushing pipe is connected to the corresponding pool body on one side of the bottom of the shear zone, so The water inlet end of the mud flushing pipe is connected to the water source through a pressure pump. 7. A method for releasing carbon sources by shearing and crushing sludge with low-speed hydrocyclone according to claim 1, characterized in that: the shape of the impeller blades is rectangular, gourd-shaped or pipa-shaped, and the impeller is connected to the center of the sludge. The area of the impeller gradually decreases at the connection point of the connecting rod, or a certain distance is maintained between the impeller and the central connecting rod. When the distance between the impeller and the central connecting rod is maintained, the impeller and the central connecting rod are fixedly connected through a cross bar.