Bubble coalescence device based on static solid interface and digestion reactor
By using a bubble pooling device with a static solid interface in an anaerobic digestion reactor, collecting and pooling small bubbles to form large bubbles, the problem of uneven mixing in the anaerobic digestion reactor is solved, and the reaction rate and mass transfer effect are improved .
Patent Information
- Application Number
- CN202421043486.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-14
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2034-05-14
AI Technical Summary
Due to the high solids and non-Newtonian fluid characteristics in the anaerobic digestion reactor, it is difficult to achieve good mixing effect, resulting in uneven mass transfer, long digestion residence time, and high investment and operation costs.
Using a bubble pooling device based on a static solid interface, small bubbles are collected and pooled through inclined plates to form large bubbles and release them, causing local turbulence and improving the mixed mass transfer process.
It improves the mixing mass transfer effect in the reactor, improves the digestion reaction rate, and reduces the additional mixing energy requirements. It is suitable for anaerobic digestion reactors with high gas production rates.
Smart Images
Figure CN222498852U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of digestion treatment, in particular to a bubble aggregation device based on static solid interface and a digestion reactor. Background Art
[0002] Anaerobic biological treatment methods can convert organic matter into biogas and are widely used in the fields of wastewater, sludge and biomass treatment. Biological anaerobic processes are usually carried out in large digestion tanks and require good mixing to achieve efficient reactions. In actual production, it is difficult to achieve good mixing due to the high solid content in the reactor. The substrate and nutrients added to the reactor are difficult to be quickly transferred and distributed throughout the reactor volume. In addition, since the working conditions of anaerobic sludge and biomass digestion have non-Newtonian fluid characteristics, the mixing energy required is greater than that of other Newtonian fluids, and mixing is more difficult to achieve.
[0003] Mixing in traditional anaerobic digesters is usually achieved by external circulation combined with mechanical mixing or external gas injection. The stirring power of a typical anaerobic digestion reactor requires 3-6 watts per cubic meter of reactor volume, and continuous or intermittent mixing can be used. The external circulation flow of the anaerobic digestion reactor is achieved by extracting the mixture in the reactor and injecting it back into the reactor at different heights or positions in the reactor. The mechanical mixing method of the anaerobic reactor can be achieved by a variety of mechanical mixers. The common method used in large anaerobic digestion reactors is to arrange a vertical shaft mixer (with or without a guide tube) in the center of the reactor. In addition, some cases of reactors with low aspect ratios have also been found to use submerged horizontal shaft mixers. For the mixing method of gas injection, part of the generated biogas is collected and compressed and then reinjected into the reactor from the low point at the bottom of multiple reactors. A guide tube is usually set in the reactor to promote the circulation flow inside the reactor.
[0004] All of the above mixing methods are aimed at generating the largest possible internal circulation, thereby generating convective mass transfer so that the newly added substrate and nutrients in the reactor are quickly dispersed throughout the reactor volume. However, due to the large volume of the reactor itself, which can usually reach several thousand cubic meters, it leads to uneven feed distribution, low process efficiency, and long digestion residence time, which further leads to increased investment and operating costs. In addition, due to the high viscosity of the sludge or slurry, the turbulence generated by the agitator cannot act on the entire reactor volume, resulting in uneven distribution of the externally introduced stirring power in the reactor, resulting in high turbulence areas around the mixing point, and some areas have little or no convective mass transfer, that is, the existence of so-called dead zones. In addition, for sludge or slurry with non-Newtonian fluid characteristics, the relative viscosity of the material in the high shear force zone around the mixer is too high, which further reduces the mixing efficiency.
[0005] In fact, the biogas produced by anaerobic digestion is usually distributed in the entire volume of the anaerobic digestion reactor in the form of small, growable bubbles. The expansion of bubble size and the buoyancy generated by the bubbles provide a potential source of energy for mixing. In theory, the kinetic energy released by the process of producing biogas in an anaerobic digestion reactor is equivalent to 10-30% of the energy corresponding to the design stirring power of a conventional digestion reactor. However, since the average size of the bubbles is very small, usually below 2 mm, the bubble size is smaller than the minimum turbulent diameter (Kolmogorov diameter, also called Kolmogorov microscale) required to induce turbulence, that is, smaller than the eddy size required to produce convective mass transfer, and its kinetic energy is too small to drive convective mass transfer. Therefore, the kinetic energy released in the biogas production process cannot be converted into the mixing energy required by the reactor, and is eventually dissipated in the form of heat release. Utility Model Content
[0006] In view of the above technical problems, the utility model discloses a bubble aggregation device and a digestion reactor based on a static solid interface, which collect small bubbles generated in the reactor, aggregate them into large bubbles and then release them, so as to generate local turbulence in the reactor, thereby improving the mixing and mass transfer process.
[0007] To this end, the technical solution of the utility model is:
[0008] A bubble coalescing device based on a static solid interface comprises a bubble coalescing component arranged in a reactor, the bubble coalescing component comprises a bubble collecting and releasing component and an inclined plate inclinedly arranged in the reactor, the bubble collecting and releasing component is connected to the upper part of the inclined plate; the bubble collecting and releasing component is provided with a gas collecting channel, the bottom of the gas collecting channel opens downward, the inclined bottom surface of the inclined plate is located below the opening, the top of the bubble collecting and releasing component is provided with a gas release hole, the gas collecting channel is connected to the gas release point; the surface of the inclined plate is made of a hydrophobic material.
[0009] Among them, the inclined plate is made of hydrophobic material. When the bubbles encounter the hydrophobic solid surface, since the contact angle between the bubbles and the solid-liquid is smaller than the flocs or particles to which they are attached, the bubbles can be desorbed from the biological mud and attached to the surface of the inclined plate. The bubbles near the surface of the inclined plate can gather together to form large bubbles, and then transfer along the inclined plate to the gas collection channel, through which the collected gas can be introduced into the gas release hole for release. The size of the released bubbles increases, which increases the velocity gradient between the bubbles and the liquid. The kinetic energy of the large bubbles forms local turbulence, realizes convective mass transfer, and makes full use of the potential and usable mixing energy of the small bubbles generated by the anaerobic digestion process.
[0010] As a further improvement of the present invention, the inclined plate is arranged to be inclined relative to the axial direction of the gas release hole.
[0011] As a further improvement of the utility model, the inclined plate has an inclination angle of 15-35°. The inclination angle is the angle between the inclined bottom surface of the inclined plate and the axis of the gas release hole. Further, the inclination angle of the inclined plate is 20-30°. This technical solution can prevent scum from settling on the surface of the inclined plate.
[0012] As a further improvement of the utility model, the upper surface of the bubble collecting and releasing component is an inclined surface, an upwardly protruding curved surface, or an upwardly protruding folded surface. Furthermore, the gas release hole is located at a position close to the highest point on the upper surface of the bubble collecting and releasing component. Furthermore, the gas release hole is located at the highest point on the upper surface of the bubble collecting and releasing component. The use of this technical solution is conducive to the release of large bubbles.
[0013] As a further improvement of the present invention, the diameter of the gas release hole is not less than 10 mm.
[0014] As a further improvement of the present invention, the bubble collecting and releasing component is in the shape of an elongated strip.
[0015] As a further improvement of the present invention, the surface of the inclined plate is hydrophobic.
[0016] As a further improvement of the present invention, the inclined plate is made of polypropylene, polyvinyl chloride, stainless steel coated with polytetrafluoroethylene, etc.
[0017] As a further improvement of the present invention, a plurality of bubble gathering components are arranged in parallel in the horizontal direction, and the ratio of the horizontal spacing b between adjacent bubble gathering components to the horizontal projection width B of the bubble gathering components satisfies b / B=0.8~0.95.
[0018] As a further improvement of the utility model, the gas release holes on each bubble aggregation component are evenly distributed on the horizontal cross section of the flow guide channel of the reactor. The horizontal cross section of the flow guide channel here can be understood as a horizontal projection plane. With this technical solution, the mixing mass transfer effect in the reactor is better.
[0019] As a further improvement of the utility model, a plurality of bubble gathering components are connected in a row by connecting pieces.
[0020] The utility model also discloses a digestion reactor, which comprises a reactor body. A flow guide channel is arranged in the reactor body. The upper part of the flow guide channel is provided with a bubble coalescing device based on a static solid interface as described in any one of the above items.
[0021] As a further improvement of the utility model, an annular gap is provided between the reactor body and the flow guide channel. With this technical solution, the collected gas is released in the form of large bubbles at the gas release hole, and the medium returns to the bottom of the reactor through the annular gap, so that the mixed mass transfer effect in the reactor is better.
[0022] Compared with the prior art, the beneficial effects of the utility model are:
[0023] First, the technical solution of the utility model uses an inclined plate to collect small bubbles and promote the aggregation of bubbles when they collide. After the bubbles are aggregated into large bubbles, their kinetic energy is released to improve the mixing effect in the reactor. Through this device, the mass transfer process in the reactor can be greatly improved, thereby increasing the digestion reaction rate and reducing the additional mixing energy required for the digestion reaction. The technical solution of the utility model is suitable for anaerobic digestion reactors with high gas production rates and using external circulation flow to achieve mixing.
[0024] Second, the technical solution of the utility model uses the inclined plate as the solid coalescence interface of the bubbles, which can greatly reduce the risk of scum accumulation. When the bubbles are introduced upward along the slope of the inclined plate in the gas collection channel to the gas release point for release, the mixing effect of the medium in the reactor can be improved, and at the same time, the scum is taken out with the release of the bubbles. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 It is a schematic structural diagram of a bubble coalescence device based on a static solid interface in a reactor according to Example 1 of the utility model.
[0026] Figure 2 It is a structural schematic diagram of a bubble coalescence device based on a static solid interface in Example 1 of the utility model.
[0027] Figure 3 It is a structural schematic diagram of a bubble coalescence device based on a static solid interface in Example 2 of the utility model.
[0028] Figure 4 It is a schematic diagram of the structure of a bubble aggregation device based on a static solid interface of Example 2 of the utility model, wherein (a) is a schematic diagram of the overall structure, and (b) is a schematic diagram of the structure of a single bubble collection and release component.
[0029] Reference numerals include:
[0030] 1-reactor, 2-flow channel, 3-bubble coalescing device, 4-medium, 5-annular gap;
[0031] 11-bubble collecting and releasing component, 12-inclined plate, 13-gas collecting channel, 14-gas releasing hole, 15-small bubbles, 16-large bubbles, 17-flocs or particles, 18-gas film;
[0032] 31-lowest point, 32-connecting piece, 33-bubble aggregation component row. DETAILED DESCRIPTION
[0033] The preferred embodiments of the present invention will be described in further detail below in conjunction with the accompanying drawings. Example
[0034] like Figure 1 and Figure 2 As shown, a bubble agglomeration device based on a static solid interface includes a plurality of bubble agglomeration components arranged in a guide channel 2 of a reactor 1, wherein the bubble agglomeration components include a bubble collecting and releasing component 11 and an inclined plate 12 inclinedly arranged in the reactor 1, wherein the bubble collecting and releasing component 11 is connected to the upper portion of the inclined plate 12; the bubble collecting and releasing component 11 is provided with a gas collecting channel 13, the bottom of the gas collecting channel 13 is downwardly open, the inclined bottom surface of the inclined plate 12 is located below the opening, a gas release hole 14 is provided on the top of the bubble collecting and releasing component 11, and the gas collecting channel 13 is connected to the gas release point; the surface of the inclined plate 12 is made of a hydrophobic material.
[0035] The inclined plate 12 is arranged to be inclined relative to the axial direction of the gas release hole 14. The inclined angle of the inclined plate 12 is 15-35°. That is, the angle between the inclined bottom surface of the inclined plate 12 and the axis of the gas release hole 14 is 15-35°. Further, the inclined angle of the inclined plate 12 is 20-30°.
[0036] Further, in this embodiment, the upper surface of the bubble collecting and releasing component 11 is an upwardly convex arc surface, and the gas releasing hole 14 is located at the highest point of the upper surface of the bubble collecting and releasing component 11. The diameter of the gas releasing hole 14 is not less than 10 mm.
[0037] Furthermore, the bubble collecting and releasing component 11 is in the shape of an elongated strip.
[0038] Furthermore, the gas release holes 14 of the plurality of bubble aggregation components are evenly arranged in the cross section of the guide channel.
[0039] With this technical solution, the small bubbles 15 generated in the reactor 1 rise to the bubble coalescing device 3 in the flow channel 2 along with the flow of the medium 4 in the reactor 1. The flocs or particles 17 attached with the small bubbles 15 rise in the flow channel 2 until they come into contact with the surface of the inclined plate 12, where the small bubbles 15 are desorbed from the flocs or particles 17 and transferred to the surface of the inclined plate 12 to form an air film 18. The flocs or particles 17 after desorption of the bubbles continue to rise along with the flow of the medium 4. Finally, the gas collected in the bubble coalescing device 3 is released in the form of larger bubbles 16 at the gas release holes 14 arranged on the device, and the medium 4 fluid flows through the annular gap 5 outside the flow channel and returns to the bottom of the reactor 1, thereby improving the mixing effect of the medium 4 in the reactor 1. Example
[0040] like Figure 3 As shown, based on Example 1, in this embodiment, a plurality of bubble-gathering members are arranged in parallel in the horizontal direction, and the ratio of the horizontal spacing b between adjacent bubble-gathering members to the horizontal projection width B of the bubble-gathering members satisfies b / B=0.8-0.95. The number of layers of the bubble-gathering members is at least one.
[0041] The gas release holes 14 on each bubble aggregation member are evenly distributed on the horizontal cross section of the flow guide channel 2. The horizontal cross section of the flow guide channel 2 here can be understood as a horizontal projection plane. With this technical solution, the mixing mass transfer effect in the reactor 1 is better. Example
[0042] like Figure 4 As shown, on the basis of Example 2, in this embodiment, the upper surface of a single bubble collecting and releasing component 11 is a folded surface, the gas release hole 14 is located at the highest point in the middle of the bubble collecting and releasing component 11, and the two distal ends of the bubble collecting and releasing component 11 are the lowest points 31. A plurality of bubble gathering components are connected to form a bubble gathering component row 33 by a connector 32. Each bubble gathering component row 33 is arranged at intervals to meet the ratio of the horizontal spacing b of adjacent bubble gathering components to the horizontal projection width B of the bubble gathering components to meet b / B=0.8~0.95. With this technical solution, the reactor 1 can be spliced according to its size, and the compatibility is better. Example
[0043] like Figure 1As shown, a digestion reactor 1 includes a reactor 1 body, a flow guide channel 2 is provided in the reactor 1 body, and a bubble agglomeration device 3 based on a static solid interface as described in any one of the above embodiments 1 to 3 is provided in the upper part of the flow guide channel 2, and the bubble agglomeration device 3 based on a static solid interface is located inside the flow guide channel 2, and the inclined plate 12 is inclined relative to the axial direction of the flow guide channel 2. An annular gap 5 is provided between the reactor 1 body and the flow guide channel 2. With this technical solution, the collected gas is released in the form of large bubbles 16 at the gas release hole 14, and the medium 4 returns to the bottom of the reactor 1 through the annular gap 5, and the mixed mass transfer effect in the reactor 1 is better.
[0044] In the description of the present invention, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are orientations or positional relationships based on the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0046] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0047] The specific implementation methods described above are preferred implementation methods of the present utility model, and are not intended to limit the specific implementation scope of the present utility model. The scope of the present utility model includes but is not limited to the specific implementation methods. All equivalent changes made in accordance with the shape and structure of the present utility model are within the protection scope of the present utility model.
Claims
1. A bubble coalescence device based on a static solid interface, characterized in that: It includes a bubble gathering component arranged in a reactor, the bubble gathering component includes a bubble collecting and releasing component and an inclined plate arranged obliquely in the reactor, the bubble collecting and releasing component is connected to the upper part of the inclined plate; the bubble collecting and releasing component is provided with a gas collecting channel, the bottom of the gas collecting channel is open downward, the inclined bottom surface of the inclined plate is located below the opening, the top of the bubble collecting and releasing component is provided with a gas release hole, the gas collecting channel is connected to the gas release point; the surface of the inclined plate is made of hydrophobic material.
2. The bubble coalescence device based on static solid interface according to claim 1, characterized in that: The inclined plate is disposed obliquely with respect to the axial direction of the gas release hole.
3. The bubble coalescence device based on static solid interface according to claim 2, characterized in that: The inclination angle of the inclined plate is 15-35°.
4. The bubble coalescence device based on static solid interface according to claim 3, characterized in that: The upper surface of the bubble collecting and releasing component is an inclined surface, an upwardly protruding arc surface or an upwardly protruding folded surface; the gas release hole is located at a position close to the highest point on the upper surface of the bubble collecting and releasing component.
5. The bubble coalescence device based on static solid interface according to claim 1, characterized in that: The diameter of the gas release hole is not less than 10 mm.
6. The bubble coalescence device based on static solid interface according to claim 1, characterized in that: The bubble collecting and releasing component is in the shape of an elongated strip.
7. The bubble coalescence device based on static solid interface according to any one of claims 1 to 6, characterized in that: A plurality of bubble gathering components are arranged in parallel in the horizontal direction, and a ratio of a horizontal spacing b between adjacent bubble gathering components to a horizontal projection width B of the bubble gathering components satisfies b / B=0.8-0.
95.
8. The bubble coalescence device based on static solid interface according to claim 7, characterized in that: A plurality of bubble merging components are connected in a row through connecting members.
9. A digestion reactor, characterized in that: It includes a reactor body, a guide channel is provided in the reactor body, an annular gap is provided between the reactor body and the guide channel, and a bubble coalescence device based on a static solid interface as described in any one of claims 1 to 8 is provided in the upper part of the guide channel.