Apparatus and method for improving wastewater purification

Abstract

An anaerobic purification apparatus for a fluid, such as wastewater, the apparatus comprising a reactor tank for anaerobic purification of the fluid and a biomass recirculation unit. The biomass recirculation unit comprises an inlet system configured to receive an influent fluid from outside, a biomass collection system for withdrawing biomass from a middle portion of the reactor tank and bringing the biomass into the biomass recirculation unit, a mixing section for connecting to the inlet system and the biomass collection system and for receiving and mixing the influent fluid with the biomass, and an outlet system for discharging a mixture of the influent fluid and the biomass to a lower portion of the reactor tank. The inlet system comprises a converging nozzle for creating a suction effect when the influent fluid flows through the converging nozzle from the inlet system to the mixing section, such that the biomass collection system withdraws biomass from the middle portion of the reactor tank into the mixing section.

Description

Technical Field

[0001] This invention relates to a biomass recycling unit for anaerobic purification equipment, used for the anaerobic purification of fluids such as wastewater. The invention also relates to an anaerobic purification device including the biomass recycling unit, and a method for anaerobic purification of fluids such as wastewater. Background Technology

[0002] Wastewater can be purified by various methods. If a fluid contains biodegradable components, it is considered wastewater. One such wastewater purification method is anaerobic treatment. This method is primarily suitable for wastewater highly contaminated with organic impurities, and preferably wastewater with a fluid temperature above 20 degrees Celsius. Most common anaerobic treatment methods utilize so-called upflow reactors, such as the UASB (Upflow Anaerobic Sludge Blanket) and EGSB (Expanded Granular Sludge Blanket) described in EP 1979273 B1, or internal circulation reactors such as those described in EP 0170332 B1 or WO 2012 / 00592A1. Such reactors are highly effective in treating highly contaminated wastewater, especially wastewater containing soluble components.

[0003] In these reactors, under suitable upward flow conditions, natural aggregates of microorganisms can form. These aggregates have high settling velocities and can be retained in the reactor by gravity separation as wastewater passes through. When the settling velocity of lighter flocs or unaggregated microorganisms falls below the design value of the gravity separation unit, these flocs or unaggregated microorganisms are flushed away. This is an ideal selection mechanism because it produces a biomass, commonly referred to as granular biomass or granular sludge, with high settling velocities and high density. These characteristics enable upflow reactors to operate at high liquid throughput and high volumetric conversion ratio (VCR), where VCR is expressed as per cubic meter per day (m³). 3 The volumetric conversion rate (VCR) of a reactor is measured in kilograms (kg) of Chemical Oxygen Demand (COD). Achieving a high VCR is ideal because, for a given wastewater flow rate, the allowable VCR determines the reactor size and thus the economics of an upflow reactor. Therefore, past developments have focused on increasing VCR, significantly leading to the development of reactors with VCRs of 7-12 kg COD per cubic meter of reactor volume per day, 10-18 kg COD per cubic meter of reactor volume per day, and 15-25 kg COD per cubic meter of reactor volume per day.

[0004] However, there are factors that limit the maximum possible volumetric conversion rate. It is well known that, in many cases, the microorganisms themselves are not the limiting factor. This can be explained by simple calculations: the density of granular biomass is typically 65 kg volatile suspended solids (VSS) / m³. 3 The conversion rate of microorganisms is expressed as specific methanogenic activity (SMA), typically 0.7 kg COD / kg VSS*day. Upflow reactors are usually filled with granular biomass to 70% of their liquid volume, therefore the maximum achievable volumetric conversion rate is 65 * 0.7 * 70% = 32 kg COD converted per cubic meter of reactor volume per day. Therefore, this theoretically achievable maximum rate exceeds the current practical volumetric conversion rate.

[0005] One of the main limiting factors for current upflow reactors is that the amount of granular biomass in the reactor should remain constant under all conditions, even if some biomass may be lost as the treated wastewater passes through. If this is not the case, the upflow reactor will lose its bioconversion capacity and cannot maintain volumetric conversion and treatment efficiency. The amount of granular biomass in the reactor depends on the balance between the growth of new granular biomass and the biomass loss with the effluent. Under ideal conditions, biomass growth exceeds loss, resulting in a net biomass surplus. In this case, granular biomass is harvested from the reactor and can be used as start-up inoculum for new reactors. If granular biomass loss exceeds growth, additional granular biomass should be supplied to maintain the conversion rate.

[0006] The growth rate of biomass is an inherent characteristic of anaerobic microorganisms and depends on the nature of organic pollutants in the wastewater. In other words, the type of anaerobic upflow reactor has no effect on the growth rate of biomass. However, it can influence the form in which anaerobic biomass develops, such as developing in the ideal granular form or in a flocculent form that is more easily lost with the treated wastewater.

[0007] The loss of biomass with treated wastewater can be controlled by the type of upflow reactor. There are two main phenomena leading to anaerobic biomass loss:

[0008] 1. Bubbles are generated in granular biomass. If these bubbles are not separated in time, they increase the buoyancy of the particles. This floating of the granular biomass can cause it to be lost along with the treated (wastewater) water, because separation is based on gravity.

[0009] 2. Granular biomass can be sheared into a more flocculated form through intensive mixing. Flocculated biomass does not have the same settling characteristics as granular biomass and will subsequently be lost along with the treated (wastewater).

[0010] Various methods have been employed to overcome the floating problem of granular biomass. For example, US2011 / 0236274 A1 uses a device that attempts to utilize the flocculation properties of biomass to separate floating granular biomass from the reactor liquid in a degassing unit. WO 2012 / 005592 A1 uses a device in which granular biomass is separated under high hydrostatic pressure in the reactor. Under these conditions, the attached bubbles dissolve again in the liquid, reducing the buoyancy of the granular biomass.

[0011] The loss of flocculated biomass due to shearing of granular biomass is controlled by the strength of the formed particles relative to the shear forces within the reactor. Pereboom (1997) demonstrated that systems with slow biomass growth have higher particle strength, meaning they are less prone to wear or decomposition than systems with rapid biomass growth. A slow growth rate also implies a low conversion rate. This conflicts with the goal of designing and operating anaerobic upflow reactors with high volumetric conversion. An optimal balance between slow growth rate and high volumetric conversion can only be found by ensuring thorough mixing of organic pollutants with granular biomass, resulting in the lowest possible substrate concentration throughout the reactor. This ensures that, on average, all granular biomass has the same low substrate concentration, contributing to overall conversion, while the growth rate remains moderate, as it depends on the substrate concentration. Under these conditions, particles of sufficient strength can be formed. Therefore, to achieve this goal, a trade-off must be struck between vigorous mixing and avoiding excessive shearing.

[0012] Excessive shearing can be avoided in upflow reactors by, for example, avoiding the use of high-speed rotating components (such as mixers or pumps for recirculated liquids and / or biomass). However, it is necessary to ensure adequate mixing of wastewater with granular biomass to achieve the desired conversion rate. Otherwise, one portion of the anaerobic biomass will be overloaded with contaminants, while another portion will receive too little contaminants to effectively promote the conversion process. Several methods for overcoming this problem are described in the art. For example, WO 2007 / 078195 A1 uses a method of pumping treated (clean, purified) effluent back to the bottom of the reactor to increase the upward flow velocity, thereby increasing mixing. Before the liquid is pumped back, the treated effluent needs to pass through at least a portion of an effluent separator to separate the granular biomass from the liquid. In another embodiment of WO 2007 / 078195 A1, it is mentioned that wastewater can be introduced at different heights within the reactor to promote mixing of the incoming contaminants with the granular biomass. Therefore, WO 2007 / 078195 A1 requires at least a portion of the separator to recycle the effluent to the bottom of the reactor and inlet points at different heights within the reactor, which is difficult to assemble.

[0013] EP 0 170 332 B1 describes an apparatus that utilizes generated biogas to create an air lift, recirculating fluid from the top of the reactor to the bottom. This creates additional mixing at the bottom of the reactor, where the influent is gently mixed with internally recirculated water. The mixed water then flows upward through a sludge bed composed of granular biomass. However, EP 0170 332 B1 requires a complex internal structure to capture the biogas, separate it from the water, and recirculate it back to the bottom of the reactor.

[0014] Therefore, there is a need for a method and system for anaerobic purification of fluids such as wastewater that achieves a better balance between slow growth rate and high volume conversion rate, thereby maintaining biomass granulation while achieving an acceptable volume conversion rate and avoiding excessive shearing. Summary of the Invention

[0015] In a first aspect, the present invention provides or includes a biomass recycling unit for an anaerobic purification apparatus for a fluid such as wastewater, the biomass recycling unit comprising: an inlet system located in the lower part of the reactor of the apparatus and for receiving inflow fluid from outside the apparatus; a biomass collection system for extracting biomass from the middle of the reactor and carrying the biomass into the biomass recycling unit; a mixing section located in the lower part of the reactor, connected to the inlet system and the biomass collection system, for receiving and mixing the inflow fluid and biomass; and an outlet system connected to the mixing section for discharging the mixture of the inflow fluid and biomass to the lower part of the reactor, wherein the inlet system includes a constricting nozzle for generating a suction effect when the inflow fluid flows from the inlet system to the mixing section through the constricting nozzle, the suction effect causing the biomass collection system to extract biomass from the middle of the reactor into the mixing section.

[0016] This invention aims to overcome the aforementioned problems and achieves optimal mixing not only by recirculating the liquid to the bottom of the reactor, but particularly by recirculating the granular biomass from the higher part of the reactor to the lower part, where it comes into contact with organic pollutants. Therefore, it is not the liquid that is recirculated, but the granular biomass itself, that is recirculated to the bottom of the reactor. Biomass recycling is driven by a jet principle, wherein the motive liquid can consist of influent, or a mixture of influent and effluent (treated fluid), or even a mixture of influent, effluent, and recirculated granular biomass. As the motive liquid passes through a converging or contracting nozzle, it can create a suction effect, drawing the granular biomass from the middle of the reactor (where the granular biomass may be loaded with less organic matter) to the bottom of the reactor (where the granular biomass mixes with the incoming (influent) fluid (wastewater, and in some embodiments, the incoming fluid may also include recirculated effluent)), thereby generating an upward velocity through the reactor. The jetting system, as described just now according to the invention, allows for very small shearing, has no rotating parts, and maintains a simple mechanical structure, thereby overcoming the disadvantages of known inventions in the art and preserving the particle size of biomass.

[0017] In a second aspect, the present invention provides an anaerobic purification device for a fluid such as wastewater, comprising: a reaction tank; at least one biomass recycling unit as described above; and at least one biomass separation device located in the lower part of the reaction tank, the at least one biomass separation device being used to receive fluid from the upper part of the reaction tank, separate (granular) biomass from the liquid in the fluid, and discharge biomass and liquid separately.

[0018] Therefore, the present invention advantageously provides an anaerobic purification device for wastewater purification, namely an upflow reactor, which has a simple structure, prevents particle loss due to floating, and allows improved mixing through the recycling of biomass and the re-contact of the recycled biomass with the inflow fluid (wastewater), while maintaining the good quality of the granular biomass.

[0019] At least one biomass separation device is preferably located in the lower part of the reaction vessel, for example, in contact with the bottom of the reactor. This avoids the difficulties that would have been encountered if these devices had to be placed in the upper part of the reaction vessel, and also promotes improved retention of granular biomass.

[0020] Throughout this specification, "upper part" or "upper section" can refer to the upper half of the reactor tank height, or the upper third of the reactor tank, or the upper quarter of the reactor tank. Similarly, "lower part" or "lower section" can refer to the lower half, lower third, or lower quarter of the reactor tank height. "Middle section" can be considered as the area encompassing the middle of the reactor tank height, such as the middle third, two-quarters, or three-quarters of the reactor tank height. The middle section can be the part of the reactor tank where the biomass and influent water are thoroughly mixed, i.e., the part where the biomass and influent mix better with each other than in the lower part of the reactor tank.

[0021] Throughout the text, the terms "solid" and "(granular) biomass" are used interchangeably because the solid particles present in the reactor are biomass. Similarly, throughout the specification, "reactor," "reactor tank," and "reactor chamber" are used interchangeably, as are "inflow liquid," "inflow fluid," and "inflow water." Likewise, "biogas" and "gas" are considered interchangeable throughout the specification.

[0022] According to an embodiment of the present invention, the biomass collection system includes at least one biomass collection pipe, the upper end of which is located in the middle of the reaction tank, at a height between 20% and 60% of the height of the reaction tank, more preferably between 25% and 60%, and even more preferably between 25% and 50%. For example, the height of at least one biomass collection pipe may be between 1 and 6 meters from the bottom of the reaction tank, more preferably between 2 and 5 meters, and even more preferably between 4 and 5 meters, wherein the height of the reaction tank is between 8 and 16 meters.

[0023] According to an embodiment of the invention, the mixing section is a mixing chamber, wherein the inlet system includes at least one feed pipe, a delivery pipe and at least one inlet pipe including a constriction nozzle, wherein a first end of the at least one feed pipe is used to receive inflow fluid and a second end of the feed pipe is connected to the delivery pipe, wherein the delivery pipe is located in the mixing chamber, and wherein the delivery pipe is further connected to at least one inlet pipe such that the inflow fluid leaves the delivery pipe and enters the mixing chamber via the constriction nozzle of the at least one inlet pipe.

[0024] According to an embodiment, a biomass collection system is used to discharge biomass into a mixing chamber, such that the biomass is mixed with an inflow fluid entering the mixing chamber via a converging nozzle of at least one inlet pipe. Therefore, in at least some embodiments, the mixing section of the biomass recycling unit can be a mixing chamber for receiving biomass from one or more biomass collection systems and receiving liquid from an inlet system, since the inlet system can discharge liquid into the mixing chamber via one or more (converging) discharge nozzles, thereby creating a negative pressure in the mixing chamber that causes biomass to be drawn from the biomass collection system and the mixture of liquid and biomass to be discharged into a reaction tank via an outlet system.

[0025] According to one embodiment, the outlet system includes at least one outlet pipe connected at a first end to a mixing chamber and discharging at a second end to the lower part of the reaction vessel. The outlet system may also include an opening in the mixing chamber, allowing a mixture of fluid and biomass to enter the reaction vessel from the mixing chamber through the opening.

[0026] According to an embodiment, at least one biomass separation device includes a substantially vertical central tube and at least one concentric shell surrounding the central tube and defining at least one concentric cavity, wherein the central tube is used to receive fluid from the upper part of the reactor tank and allow the fluid to flow downward to the bottom of the biomass separation device, and wherein the at least one concentric cavity includes a plurality of helical channels for allowing fluid to flow upward and causing biomass to slide downward.

[0027] According to an embodiment, the top of at least one biomass separation device, located above at least one concentric shell, is connected to an outflow system configured to carry clean liquid that has flowed upwards out of the device. Using this structure, the biomass separation device exhibits good separation characteristics and can occupy a smaller volume compared to other known settling devices, while also maintaining structural stability because at least one concentric shell can be substantially cylindrical.

[0028] According to an embodiment, the device includes at least one gas separation device located at the top of the reaction vessel, wherein the fluid outlet of at least one gas separation device is connected to a downcomer pipe, the downcomer pipe corresponding to or connected to the central pipe of at least one biomass separation device.

[0029] In one embodiment, clean liquid (effluent) discharged from the upflow reactor via the effluent system is mixed with the inflow water and pumped back to the inlet system. This facilitates operation of the biomass recycling unit in the absence of effluent, where there is temporarily no wastewater inflow.

[0030] According to embodiments, at least one biomass separation device includes or is connected to a biomass collection chamber located at the bottom of the at least one biomass separation device. The biomass collection chamber is configured to receive biomass and discharge it to the outside of the at least one biomass separation device. The separated biomass can be reused in the purification process and can be directly returned to the reaction tank or returned to the reaction tank via an inlet system. For example, according to an embodiment, the device further includes a biomass extraction pump configured to carry biomass from the biomass collection chamber into the inlet system of at least one biomass recycling unit. In this way, the biomass can be mixed with the inflow and enter the sludge bed in the reaction tank via the biomass recycling unit. In another example, according to an embodiment, the device further includes a biomass extraction pump configured to carry biomass from the biomass collection chamber into the reaction tank, i.e., the biomass enters the reaction tank directly without mixing with other fluids.

[0031] According to an embodiment, the equipment includes multiple biomass separation devices and multiple biomass recycling units, wherein each pair of biomass separation devices and biomass recycling units is configured to operate according to the paragraphs above. For example, the reactor tank can be large in size and can be configured with two or more sets of biomass recycling units, biomass separation devices, biomass collection systems, gas separation devices, and downpipes, along with their respective components, each set adjacent to each other. The entire equipment can even be constructed in a single structure for ease of transport and placement. As another example, there can be several sets of biomass recycling units and biomass separation devices, and one or more gas separation devices connected to downpipes, wherein the downpipes are divided into several downpipes, each downpipe connected to a biomass separation device. Clearly, these are examples of possible combinations, but other combinations of different parts are also possible.

[0032] Thirdly, a method for anaerobic purification of fluids such as wastewater using an anaerobic purification device is provided. The method includes the following steps: receiving inflow fluid from outside the device and biomass from the middle of the reaction tank of the device through a biomass recycling unit; and discharging the mixture of inflow fluid and biomass to the lower part of the reaction tank through the biomass recycling unit. The biomass recycling unit includes an inlet system through which the inflow fluid enters. The method further includes generating a suction effect when the inflow fluid leaves the inlet system through a converging nozzle. This suction effect causes biomass to be drawn from the middle of the reaction tank into the biomass recycling unit to mix with the inflow fluid.

[0033] According to an embodiment, the method further includes: receiving fluid from the upper part of the reaction tank through a biomass separation device located at the lower part of the reaction tank; separating biomass and liquid in the received fluid through the biomass separation device; and discharging biomass and liquid separately through the biomass separation device, thereby discharging clean liquid out of the equipment. Attached Figure Description

[0034] The present invention will now be described in more detail with reference to the accompanying drawings, wherein:

[0035] Figure 1 A vertical cross-section of an anaerobic purification device according to an embodiment of the present invention is shown.

[0036] Figure 2 A perspective cross-section of a portion of an anaerobic purification device according to an embodiment of the present invention is shown.

[0037] Figure 3 A cross-section of a biomass recycling unit according to an embodiment of the present invention is shown.

[0038] Figure 4A vertical cross-section of an anaerobic purification device according to an embodiment of the present invention is shown.

[0039] Figure 5 A perspective cross-section of a portion of an anaerobic purification device according to an embodiment of the present invention is shown.

[0040] Figure 6 A cross-section of a biomass recycling unit according to an embodiment of the present invention is shown.

[0041] Figure 7A A vertical cross-section of a purification device according to an embodiment of the present invention is shown.

[0042] Figure 7B A vertical cross-section of a purification device according to an embodiment of the present invention is shown.

[0043] Figure 8 A flowchart illustrating method steps according to an embodiment of the present invention is shown.

[0044] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope or protection defined by the claims. Detailed Implementation

[0045] Although the instructions will generally be based on fluid purification, it is preferably applied to wastewater, but it will be apparent to those skilled in the art that any other suitable fluid may be used.

[0046] Before describing the accompanying drawings in detail, it should be noted that throughout this application, terms such as upper, lower, upper / middle / lower, upper / lower portion, top / bottom, and top / bottom portion are used. Unless otherwise specified, these definitions refer to the location where the equipment (purification device) is operating or preparing to operate.

[0047] Throughout the specification, terms such as vertical section and horizontal section are used. A vertical section should be understood as a section formed along a longitudinal plane including the longitudinal axis (denoted by Y in at least some figures), and a horizontal section should be understood as a section formed along a transverse plane including the transverse axis (denoted by X in at least some figures). In all figures, the same numbers denote the same features.

[0048] Figure 1 A vertical cross-section of an anaerobic purification device according to an embodiment of the present invention is shown. Figure 2 A perspective cross-section of a portion of an anaerobic purification device according to an embodiment of the present invention is shown. For ease of explanation, [the following will also be discussed]. Figure 1 and Figure 2 Describe it.

[0049] The anaerobic purification equipment 1 includes a reaction tank 10, a biomass recycling unit 20, a biomass separation device 30, and a gas separation device 40.

[0050] The biomass recycling unit 20 is at least partially located in the lower part of the reactor, such as the lower half or lower third, for example, in contact with the bottom of the reactor. The biomass recycling unit 20 includes a biomass collection system 24 for collecting biomass from the biomass bed in the middle of the reactor and carrying it to the lower part of the reactor 10. Figure 1 and Figure 2 In the illustrated embodiment, the biomass collection system 24 includes a collection pipe, but may also include multiple pipes, and may further include an inlet funnel on the collection pipe to facilitate easy conveyance of biomass from the biomass bed into the pipe in a vertically downward direction. The length of the pipe can vary from 20% to 60% of the reactor height, more preferably from 25% to 50%. For example, for a reactor height between 8 meters and 16 meters, the pipe length can vary from 1 meter to 6 meters, more preferably from 2 meters to 5 meters, and even more preferably from 4 meters to 5 meters. Such a length allows biomass to be drawn from the middle of the biomass bed (the middle of the reactor) and returned to the bottom of the biomass bed. In the lower portion of the biomass collection system 24, the collection pipe may form a bend with an angle varying between 90 degrees and 135 degrees relative to the longitudinal axis of the collection pipe. Figure 1 and 2 In the example shown, the angle is approximately 90 degrees.

[0051] The biomass recycling unit 20 also includes an inlet system 22. Figure 1 and 2 In one embodiment, the inlet system includes an inlet pipe, but it may also include multiple inlet pipes. The inlet pipe of the inlet system 22 includes a converging nozzle 23 (in... Figure 3 (See image below), and connected to a bend, so that the inflowing water is discharged through the converging nozzle 23. In a portion of the biomass recycling unit 20, the inflowing water is discharged from the inlet system 22, which is the mixing section 25. The high speed of the water in the converging nozzle 23 creates a suction effect, which pulls the biomass downward through the biomass collection system 24 and into the mixing section 25. That is, the converging nozzle 23 creates a jet system in which the inflowing water is the motive fluid that creates the suction effect. The biomass and the inflowing water are mixed in the mixing section 25. The mixing section 25 may be a pipe section (e.g., in...) Figure 1 and 2 In one embodiment, or in another embodiment, mixing section 25 may be a mixing chamber. The mixed influent and biomass leave the biomass recycling unit and enter the lower part of the reactor 10 through outlet system 26, which may include one or more outlet pipes.

[0052] By generating additional mixing at the bottom (lower section) of the reactor and recycling the biomass from the upper (middle) section down to the lower section, the COD-loaded biomass at the bottom of the reactor is replaced by less COD-loaded biomass from the higher section. This allows for better mixing and, consequently, produces higher-quality granular biomass, resulting in better retention of the granular biomass in the upflow reactor.

[0053] exist Figure 1 and 2 In one embodiment, the biomass recycling unit 20 comprises two sets, each set including a biomass collection system 24 (collection pipe), an inlet system 22 (inlet pipe), a mixing section 25, and an outlet system 26 (outlet pipe). However, it should be noted that the biomass recycling unit 20 according to the invention may also include one or more sets. Two sets of biomass recycling units spaced approximately equidistantly allow biomass to be collected from different locations within the reactor 10 and carried to different locations in the lower part of the reactor 10, resulting in a more uniform distribution of biomass across the entire biomass bed. However, it will be apparent to those skilled in the art that other configurations are also possible.

[0054] The biomass separation device 30 is located at the lower part of the reaction tank 10 and is configured to receive fluid from the upper part of the reaction tank in order to separate the biomass (solid) from the liquid in the fluid and discharge them separately, with the clean liquid discharged from the equipment. Figure 1 and 2 In one embodiment, the biomass separation device includes a vertically or substantially vertically extending central pipe 31 through which fluid from the upper part of the reaction tank 10 is received during operation. The lower end of the central pipe 31 discharges into a biomass collection chamber 35 at the bottom of the biomass separation device 30, preferably located at the center below the biomass separation device 30. The biomass separation device also includes at least one concentric outer shell 32 (in... Figure 2(More clearly in the image), a concentric shell 32 surrounds a central tube 31 and defines at least one concentric cavity. The at least one concentric cavity is filled with a helical channel 33 extending vertically and spiraling around the central tube 31. The central tube 31 is configured to receive fluid from the upper part of the reaction vessel 10 and allow the fluid to flow downwards until it reaches the bottom of the biomass separation device 30. At the bottom, in the cavity forming the biomass collection chamber 35, the fluid from the central tube 31 has space to be redirected using its own energy and moves upwards through the multiple helical channels 33 of the concentric cavity. Due to friction with the walls of the helical channels 33, as the fluid moves upwards, some biomass (solid) may still separate from the liquid and move downwards due to its higher density, settling in the biomass collection chamber 35. At least one shell may define a cylindrical shape, and the biomass collection chamber 35 may have a conical or funnel-shaped shape with an opening at the narrow end of the shape to facilitate the settling of solid particles (biomass).

[0055] The top of the biomass separation device 30, located above at least one concentric housing, can be connected to an outflow system 34 configured to carry clean liquid that has flowed upwards out of the device. The top of the biomass separation device 30 may include at least one partition structure for creating at least two compartments into which liquid that has flowed upwards through the spiral channel 33 can reach, with each compartment connected to the outflow system 34. This allows for a controlled distribution of the liquid reaching the top of the biomass separation device 30.

[0056] The biomass separation device includes at least one concentric shell surrounding the central tube 31, but may also include at least two or more concentric shells, depending on the size of the biomass separation device 30.

[0057] It should be noted that, Figure 1 and Figure 2 The biomass separation device of the embodiment is one possibility, but it will be apparent to those skilled in the art that biomass separation devices with different structures (excluding the concentric chamber, preferably also located at the bottom / lower part of the reaction tank) can be combined with the biomass recycling unit 20 of the present invention for use in purification equipment.

[0058] The effluent system 34 may include one or more effluent pipes and may carry clean liquid (effluent) to the outside of the anaerobic purification device, or may recycle at least a portion of the clean liquid back to the reaction vessel, as will be described below. Figure 7A and Figure 7B As shown. Biomass separated from the liquid can be carried to the biomass collection chamber 35 via biomass extraction pump 36 and biomass extraction tube 37. Biomass extraction tube 37 can carry the biomass out of the equipment or back into the reaction tank 10. This will... Figure 7A and7B Detailed explanation follows.

[0059] exist Figure 1 The anaerobic purification device also shows a gas separation device 40. In the reaction tank 10, the fluid reacts with biomass in the sludge (biomass) bed to produce biogas, and the fluid moves upward. The gas separation device 40 can be installed at the upper part of the reaction tank 10 to separate the gas from the biomass in the liquid and fluid. Preferably, the top of the gas separation device 40, more preferably the top edge or top surface, is located at or below the liquid surface 60, such that the remaining components of the device inside the reaction tank 10 are below the liquid surface. The gas separation device 40 can have different shapes. In one embodiment of the invention, such as... Figure 1 As shown, the gas separation device 40 may include at least one concentric shell surrounding a central portion, the at least one concentric structure defining at least one concentric cavity, wherein the at least one concentric cavity includes a plurality of helical channels, such that fluid that has reached the upper part of the reaction tank 10 enters the gas separation device 40 through the top opening of the at least one concentric shell. As the fluid flows downward through the helical channels, gas particles will separate from the liquid and solids due to the walls of the helical channels, the gas will move upward, be collected in the upper part of the reaction tank 10, and discharged via a gas outlet 42 located in the upper part of the reaction tank (device). Then, the fluid containing liquid and solids will flow downward through a fluid outlet 41, which is connected to a downcomer 31, corresponding to or connected to the central pipe 31 of the biomass separation device. As described above, it should be noted that... Figure 1 and 2 The gas separation device described in the embodiment is one possibility, but it will be apparent to those skilled in the art that gas separation devices with different structures (excluding the concentric chamber, preferably also located at the top of the reaction vessel) can be combined with the biomass recycling unit of the present invention for use in purification equipment.

[0060] Figure 3 A cross-section of a biomass recycling unit according to an embodiment of the present invention is shown. Figure 3 In the middle, you can see more details of what has been combined above. Figure 1 and Figure 2 The components of the biomass recycling unit 20 are described as follows: inlet system 22, biomass collection system 24, mixing section 25, and outlet system 26. (See also...) Figure 3As seen more clearly, the biomass collection system 24 defines a bend that terminates at or overlaps with the mixing section 25. The inlet system 22 is also connected to the mixing section 25, and the inflow mixes with the biomass drawn into the mixing section 25 due to a suction effect, then exits the biomass recycling unit through the outlet system 26. According to this embodiment, the biomass recycling unit can be placed separately from the remaining components (gas separator and biomass separator) in the reactor and can be placed independently within an existing anaerobic purification unit.

[0061] Figure 4 A vertical cross-section of an anaerobic purification device according to an embodiment of the present invention is shown. Figure 5 A perspective cross-section of a portion of an anaerobic purification device according to an embodiment of the present invention is shown. Figure 6 A cross-section of a biomass recycling unit according to an embodiment of the present invention is shown. For ease of explanation, it will also be described... Figure 4 , Figure 5 and Figure 6 .

[0062] Figure 4 , Figure 5 and Figure 6 Anaerobic purification equipment is similar to Figure 1 , Figure 2 and Figure 3 The equipment is described below. Descriptions of the biomass separation unit 30 and the gas separation unit 40 will be omitted as they are similar to those described above.

[0063] Figure 4 , Figure 5 and Figure 6 A biomass recycling unit 20 is described, which has the same characteristics as... Figure 1 , Figure 2 and Figure 3 Some features that are different from those of the others. Figure 4 , Figure 5 and Figure 6 In the biomass recycling unit 20, the mixing section 25 corresponds to the mixing chamber 25. The inlet system 22 includes at least one feed pipe 27 (due to perspective, in...) Figure 5 As can be seen in the image, fluid flowing in from outside the device enters through this feed pipe. However, the inlet system according to this embodiment has additional pipes. It also includes a delivery pipe 28 and at least one inlet pipe 22, the inlet pipe 22 including a converging nozzle 23 (in... Figure 6(More clearly visible in the image). At least one feed pipe 27 has a first end configured to receive the inflow fluid, and a second end connected to a delivery pipe 28. The delivery pipe 28 is located inside the mixing chamber 25, extends within the mixing chamber, and terminates at or further connects to at least one inlet pipe 22, such that the inflow fluid exits the delivery pipe 28 and enters the mixing chamber 25 via a converging nozzle 23 of the at least one inlet pipe 22. It should be noted that the reference numerals for the inlet pipes are the same as those for the inlet system, as this is the simplest implementation. Figure 1 , Figure 2 and Figure 3 As shown, the inlet system includes an inlet pipe, which corresponds to Figure 4 , Figure 5 and Figure 6 The inlet pipe.

[0064] The mixing chamber 25 can have various shapes, such as a cubic box, or as... Figure 4 , Figure 5 and Figure 6 The mixing chamber 25 is preferably located in the lower part of the reaction tank 10, for example, at the bottom of the reaction tank, and more preferably at least partially below the biomass separation device 30. The function of the mixing chamber 25 (or mixing section) is to mix the biomass from the biomass collection system 24 with the inflow water and discharge the mixture into the lower part of the reaction tank 10 through one or more outlet pipes of the outlet system 26. With this structure, the mixing chamber 25 does not need to connect a biomass collection pipe 24 to an inlet pipe 22 and an outlet pipe 26. This means that one or more biomass collection systems with collection pipes 24, an inlet system 22 with constricting nozzles 23, and an outlet system 26 with outlet pipes can be connected to a single mixing chamber 25, which also allows for a more compact structure formed by the biomass recycling unit 20 and the biomass separation device 30.

[0065] The biomass collection chamber 35 is at least partially located below the biomass separation device 30, preferably at a central position below the biomass separation device 30. The mixing chamber 25 preferably surrounds the biomass collection chamber 35 and has an annular shape that rotates about a vertical axis, with the outer wall of the biomass collection chamber 35 contacting or forming the inner wall of the annular chamber (i.e., the mixing chamber 25). This arrangement can effectively utilize space because it creates a compact structure. In one embodiment, the biomass separation device 30, the biomass collection chamber 35, and the mixing chamber 25 are constructed in a single structure or assembled together.

[0066] The inlet system 22 of the biomass recycling unit 20 introduces inflow water into the mixing chamber 25 via at least one feed pipe 27. This inflow water includes fluid from outside the equipment, which can be either influent or recycled effluent, and may also include recycled biomass that has exited the equipment and been recycled via a biomass extraction pump 36 and a biomass extraction pipe 37 connected to the biomass collection chamber 35. Inside the mixing chamber 25, a delivery pipe 28 is connected to the feed pipe 27 and is also connected to at least one inlet pipe 22 having a constriction nozzle 23 through which influent enters the mixing chamber 25. A cavity is formed inside the mixing chamber 25, within which the delivery pipe 28 is located, and the cavity is configured to contain biomass collected from the reaction tank 10 by the biomass collection system 24 via a suction effect, more specifically from the center of the reaction tank, caused by the influent entering the mixing chamber 25 through the constriction nozzle 23 of the inlet pipe 22. A biomass harvesting system may include at least one collection tube, preferably at least two collection tubes, such as... Figure 4 As shown. Biomass and influent are mixed in mixing chamber 25 and discharged through one or more outlet pipes or outlet openings 26 of the outlet system connecting mixing chamber 25 to reactor 10. The mixture of influent and biomass discharged from mixing chamber 25 enters the lower part of reactor 10.

[0067] exist Figure 6 In the middle, you can see more details in the combination of the above text. Figure 4 and Figure 5 The components of the biomass recycling unit 20 are connected to the conveying pipe 28. Figure 6 The inlet system (not visible in the middle) includes the inlet pipe 22, the biomass collection system 24, the mixing chamber 25, and the outlet system 26. For example... Figure 6 As can be seen more clearly, the biomass collection system 24 discharges biomass into the mixing chamber 25. The inlet pipe 22, including the converging nozzle 23, also discharges into the mixing chamber 25, and the inflow mixes with the biomass that has been drawn into the mixing section 25 due to the suction effect of the converging nozzle 23, and then leaves the biomass recycling unit through the outlet system 26.

[0068] Figure 7A A vertical cross-section of the purification apparatus according to an embodiment of the present invention is shown. Solids (granular biomass) settling in the biomass collection chamber 35 are removed from the biomass collection chamber via a biomass extraction pump 36 and a biomass extraction pipe 37. The biomass can be recycled so that it can be reintroduced into the biomass recycling unit 20 along with inflows received from outside the equipment. Figure 7A The illustrated embodiment (which can be applied to the device described in any of the above figures) is in Figure 7AThe piping system for entering and leaving reaction vessel 10, which is not visible in the above figure, can be seen.

[0069] exist Figure 7A In this embodiment, by means of an inflow pump 14, the inflow received from outside the equipment is conveyed by an inlet system 22 (the inlet system shown here comprises a long pipe discharged in the biomass recycling unit). Then, in the inlet system, the inflow is mixed with solids (biomass) removed from the biomass collection chamber 35, which are then pumped by a biomass extraction pump 36 through a biomass extraction pipe 37 (in... Figure 5 (As can also be seen) it is pumped out from the biomass collection chamber 35. Then, through the inlet system 22, the fluid received from outside the equipment and the biomass removed from the biomass collection chamber 35 are mixed and transported to the biomass recycling unit 20. Therefore, in Figure 7A In one embodiment, the biomass separated from the liquid is recycled back into the mixing chamber 25 along with the inflow fluid received from the outside. The biomass and fluid are then mixed in the mixing chamber 25 with additional biomass collected from the higher (middle) section of the reaction vessel 10 and enter the lower section of the reaction vessel 10.

[0070] exist Figure 7A In some embodiments, additionally or alternatively, a portion of the clean liquid (effluent) removed from the device via the effluent system 34 is recycled and mixed with the influent received from the outside. Depending on the amount of impurities in the influent received from the outside, using a portion of the clean liquid can help reduce the concentration of impurities discharged from the lower part of the reaction vessel 10.

[0071] Figure 7B A vertical cross-section of a purification device according to an embodiment of the present invention is shown. Figure 7A The difference is that, in Figure 7B In this embodiment, the biomass in the biomass collection chamber 35 is not recycled into the biomass recycling unit 20 along with inflows from outside the equipment. Figure 7B In this embodiment, the biomass in the biomass collection chamber 35 is separately recycled back to the reaction tank 10, which is accomplished using the biomass extraction pipe 37 under the action of the biomass extraction pump 36. The biomass is reintroduced into the sludge bed inside the reaction tank at a height lower than the height at which the biomass is collected into the biomass recycling unit. Figure 7B The embodiments provide alternative ways to reuse separated biomass.

[0072] Figure 8A flowchart of the method steps according to an embodiment of the present invention is shown. First, the method includes a receiving step 801, in which an inflow fluid from outside the equipment and biomass from the middle of the reaction tank are received by a biomass recycling unit 20, preferably located at the lower part of the reaction tank 10. This receiving step has been described above in conjunction with the preceding drawings.

[0073] Step 802 includes discharging the mixture of influent and biomass into the lower part of the reaction tank 10 via the biomass recycling unit 20. As described above, the advantage of collecting biomass from the upper part of the reaction tank and reintroducing it into the lower part is that it allows biomass with a lower COD concentration to be brought to the lower part and mixes better, thereby achieving better mixing of biomass and fluids.

[0074] The biomass recycling unit 20 includes an inlet system 22 through which inflow fluid enters, and the method further includes: when the inflow fluid leaves the inlet system 22 through a constriction nozzle 23, a suction effect is generated, which causes biomass to be drawn from the middle of the reactor tank 10 into the biomass recycling unit 20 to mix with the inflow fluid.

[0075] The method may further include receiving fluid from the upper part of the reaction tank 10 via a biomass separation device 30, which is preferably also located at the lower part of the reaction tank. According to one embodiment, the fluid may originate from a gas separation device 40 located at the upper part. The method may also include separating the solids (biomass) from the liquid in the received fluid via the biomass separation device 30, and discharging the biomass and liquid separately via the biomass separation device 30.

[0076] It should be noted that the steps of this method are described as starting from step 801, but the purification process occurs continuously within a certain time period of the repeated step flow, so these steps should be considered as consecutive.

[0077] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope or protection defined by the claims.

[0078] While the invention has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes can be made and elements can be substituted with equivalents without departing from the scope of the invention. Furthermore, numerous modifications can be made to adapt particular situations or materials to the teachings of the invention without departing from the basic scope of the invention. Therefore, the invention is not limited to the specific embodiments disclosed, but will include all embodiments falling within the scope of the appended claims.

[0079] In particular, specific features of various aspects of the invention can be combined. One aspect of the invention can be further advantageously enhanced by adding features described with respect to another aspect of the invention.

[0080] It should be understood that the present invention is limited only by the appended claims and their technical equivalents. In this document and its claims, the verb "comprising" and its variations are used in their non-limiting sense to mean including the items following the word, but not excluding items not specifically mentioned. Furthermore, the use of the indefinite article "a" or "an" to refer to an element does not exclude the possibility of more than one element, unless the context explicitly requires exactly one element. The indefinite article "a" or "an" generally means "at least one".

[0081] Figure Labels

[0082] 1 Anaerobic purification equipment

[0083] 10 reaction vessels

[0084] 14 Inflow Pump

[0085] 20 biomass recycling units

[0086] 22 (Inlet system or inlet pipe of the biomass recycling unit)

[0087] 23 Shrink nozzle

[0088] 24. Biomass collection system or collection pipe

[0089] 25 mixing sections / mixing chambers

[0090] 26. (The outlet system or outlet pipe of the biomass recycling unit)

[0091] 27 (Inlet system) Feed pipe

[0092] 28 (Inlet system) delivery pipe

[0093] 30 Biomass Separation Unit

[0094] 31 central tube

[0095] 32 concentric shells

[0096] 33 Spiral Channels

[0097] 34 outflow system

[0098] 35 Biomass Collection Chamber

[0099] 36 biomass extraction pumps

[0100] 37 Biomass Extraction Tube

[0101] 40 Gas Separation Unit

[0102] 42 Gas outlet

[0103] 60 liquid level

Claims

1. An anaerobic purification device (1) for fluids, the anaerobic purification device comprising: - Reaction vessel (10); as well as - At least one biomass recycling unit (20) located inside the reactor, the biomass recycling unit (20) comprising: - Inlet system (22), which is located in the lower part of the reaction vessel (10) and is configured to receive inflow fluid from outside the equipment; - Biomass collection system (24), the biomass collection system (24) is configured to extract biomass from the middle of the reaction tank (10) and bring the biomass into the biomass recycling unit (20), wherein the middle of the reaction tank is located above the lower part of the reaction tank, and the middle of the reaction tank is defined as being between 20% and 60% of the height of the reaction tank from the bottom of the reaction tank. - A mixing section (25), located at the bottom within the reaction vessel (10), is connected to the inlet system (22) and the biomass collection system (24), and is configured to receive and mix the inflow fluid with the biomass; and - Outlet system (26), which is connected to the mixing section (25) and configured to discharge the mixture of the inflowing fluid and biomass to the lower part of the reaction tank (10), The inlet system (22) includes a converging nozzle (23), which is configured to generate a suction effect when the inflowing fluid flows from the inlet system (22) to the mixing section (25) through the converging nozzle (23). The suction effect causes the biomass collection system (24) to extract biomass from the middle of the reaction tank (10) into the mixing section (25).

2. The anaerobic purification device (1) according to claim 1 further includes at least one biomass separation device (30) located in the lower part of the reaction tank (10), the at least one biomass separation device (30) being configured to receive fluid from the upper part of the reaction tank (10) and separate the biomass and liquid in the fluid and discharge the biomass and liquid respectively, thereby discharging clean liquid out of the device, wherein the upper part of the reaction tank is located above the middle part of the reaction tank.

3. The anaerobic purification device (1) according to claim 1 or 2, wherein the biomass collection system (24) includes or is connected to at least one biomass collection pipe, the upper end of which is located in the middle of the reaction vessel (10).

4. The anaerobic purification apparatus (1) according to claim 1 or 2, wherein the mixing section (25) corresponds to the mixing chamber, wherein the inlet system (22) includes at least one feed pipe (27), a delivery pipe (28) and at least one inlet pipe including a constriction nozzle (23), wherein a first end of the at least one feed pipe (27) is configured to receive inflow fluid, and a second end of the at least one feed pipe (27) is connected to the delivery pipe (28), wherein the delivery pipe (28) is located inside the mixing chamber, and the delivery pipe (28) is also connected to at least one inlet pipe such that the inflow fluid leaves the delivery pipe (28) and enters the mixing chamber via the constriction nozzle (23) of the at least one inlet pipe.

5. The anaerobic purification device (1) according to claim 4, wherein the biomass collection system (24) is configured to discharge biomass into a mixing chamber such that the biomass is mixed with the inflow fluid entering the mixing chamber via a converging nozzle (23) through at least one inlet pipe.

6. The anaerobic purification device (1) according to claim 4, wherein the outlet system (26) includes at least one outlet pipe, the first end of the at least one outlet pipe being connected to the mixing chamber, and the second end of the at least one outlet pipe discharging to the lower part of the reaction vessel (10).

7. The anaerobic purification device (1) according to claim 2, wherein at least one biomass separation device (30) comprises a substantially vertical central tube (31) and at least one concentric shell (32), the at least one concentric shell surrounding the central tube and defining at least one concentric cavity, wherein the central tube is configured to receive fluid from the upper part of the reaction vessel (10) and allow fluid to flow downward to the bottom of the biomass separation device, and wherein at least one concentric cavity comprises a plurality of helical channels (33), the helical channels being configured to allow fluid to flow upward and cause biomass to slide downward.

8. The anaerobic purification device (1) according to claim 7, wherein the top of at least one biomass separation device (30) located above at least one concentric shell (32) is connected to an outflow system (34) configured to transport clean liquid that has flowed upward out of the device.

9. The anaerobic purification device (1) according to any one of claims 7-8 further includes at least one gas separation device (40) located at the upper part of the reaction tank (10), wherein the fluid outlet (41) of the at least one gas separation device (40) is connected to a downcomer pipe, the downcomer pipe corresponding to or connected to the central pipe (31) of at least one biomass separation device (30).

10. The anaerobic purification device (1) according to claim 2, wherein at least one biomass separation device (30) includes a biomass collection chamber (35) located at the bottom of at least one biomass separation device (30) and configured to receive biomass and discharge biomass to the outside of at least one biomass separation device (30).

11. The anaerobic purification device (1) according to claim 10, further comprising a biomass extraction pump (36) configured to carry biomass from the biomass collection chamber (35) into the inlet system (22) of at least one biomass recycling unit (20).

12. The anaerobic purification device (1) according to claim 10 further includes a biomass extraction pump (36) configured to carry biomass from the biomass collection chamber (35) into the reaction vessel (10).

13. The anaerobic purification device (1) according to claim 2, comprising a plurality of biomass separation devices (30) and a plurality of biomass recycling units (20), wherein each pair of biomass separation devices (30) and biomass recycling units (20) is configured to operate according to claim 2.

14. The anaerobic purification device (1) according to claim 1, wherein the middle part of the reaction tank is defined as being between 25% and 50% of the height of the reaction tank from the bottom of the reaction tank.

15. The anaerobic purification device (1) according to claim 1, wherein the fluid comprises wastewater.

16. A method for anaerobic purification of a fluid using the anaerobic purification device (1) according to any one of claims 1-15, comprising the following steps: - The inlet system (22) of the biomass recycling unit (20) of the equipment receives inflow fluid from outside the equipment and biomass from the middle of the reaction tank (10) of the equipment; - Biomass is extracted from the fluid inside the reaction tank (10) through the biomass collection system in the biomass recycling unit (20) located inside the reaction tank (10) and brought into the mixing chamber of the biomass recycling unit (20); - The inflowing fluid and biomass are mixed through the mixing section (25); as well as - The mixture of inflowing fluid and biomass is discharged to the lower part of the reaction tank (10) through the outlet system (26) of the biomass recycling unit (20). The method further includes: when the inflow fluid leaves the inlet system (22) through the constriction nozzle (23), a suction effect is generated, which causes the biomass to be drawn from the middle of the reaction tank (10) into the biomass recycling unit (20) to mix with the inflow fluid.

17. The method according to claim 16, wherein, When the method is operated by the anaerobic purification device according to any one of claims 2-15, the method further includes the following steps: - Fluid from the upper part of the reaction tank (10) is received by a biomass separation device (30) located at the lower part of the reaction tank (10). - The biomass in the received fluid is separated from the liquid by a biomass separation device (30); and - Biomass and liquid are discharged separately by the biomass separation device (30), thereby cleaning the liquid out of the device.

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