CN113582334B - A circulating fluidized sludge bed anaerobic reactor - Google Patents

Abstract

The invention discloses a CFSB anaerobic reactor, which comprises a reactor body, wherein an inner cylinder, a scum baffle plate and a water collecting tank are arranged in the reactor body; the upper end and the lower end of the inner cylinder are open, a gap is arranged between the inner cylinder and the reactor body, and the gap is a sludge catcher; the upper part of the inner cylinder is a conical contraction part, and the top end of the conical contraction part is a water collecting port; the scum baffle is arranged on the upper side of the water receiving opening and comprises a lower baffle matched with the shape of the conical shrinkage part and an upper baffle matched with the shape of the water receiving opening; the outer side of the scum baffle is provided with a circulating water outlet device; the upper part of the reactor body is a gas collecting area, the water collecting tank is arranged below the gas collecting area, and the top of the scum baffle is higher than the water collecting tank; the lower part of the reactor body is provided with an inverted cone-shaped mixing part; the lower part of the reactor body is also provided with a water inlet and a circulating water inlet device communicated with the circulating water outlet device. According to the technical scheme, a three-phase separator is not adopted, the equipment utilization rate is high, and the sludge precipitation efficiency is high.

Description

A circulating fluidized sludge bed anaerobic reactor

technical field

The invention belongs to sewage treatment equipment, in particular to a circulating fluidized sludge bed anaerobic reactor.

Background technique

The traditional anaerobic digestion technology for sewage treatment includes three process technologies: upflow anaerobic sludge bed reactor UASB, expanded granular sludge bed reactor EGSB and internal circulation anaerobic reactor IC. The EGSB and IC reactors are improved and optimized based on UASB, and both of them have classic three-phase separators in their reactors.

Chinese patent CN213294855U discloses an internal circulation anaerobic reactor, including a shell, the shell is a closed structure; the lower part of the shell is provided with a water inlet, and the upper part is provided with a water collection tank around the wall of the shell. The upper part of the casing is provided with a water outlet corresponding to the position of the water collection tank, and the water outlet is connected with the water collection tank; an inner cylinder with open upper and lower ends is also provided in the housing, and a swirling water distributor is provided under the inner cylinder. The swirling water distributor is located inside the inner cylinder and connected to the water inlet; a three-phase separator is arranged above the inner cylinder, the edge of the three-phase separator fits with the inner wall of the shell, and the three-phase separator is located under the water collection tank; The inner cylinder is filled with sludge particles; there is a gap between the inner cylinder and the three-phase separator and the cyclone water distributor. This technology has the problem of scum clogging of the three-phase separator, and the equipment volume occupied by the three-phase separator and its upper sedimentation zone is large, occupying the volume of the reaction zone, and the utilization rate of the anaerobic reactor is low. In addition, because of the high-speed water flow out of the upper outlet of the inner cylinder, the diameter of the water flow impacts the three-phase separator, making it difficult to separate the mud and water in the three-phase separator.

Chinese patent CN213012184U discloses a UASB wastewater anaerobic reactor, including a reaction tank, the upper end of the reaction tank is provided with a biogas collection port and a waste water outlet, and a pulse water distributor is arranged above the reaction tank. A three-phase separator, a suspension area, a sludge area and a water distribution system are sequentially arranged in the reaction tank, the pulse water distributor is connected to the water distribution system, and a water pump is externally connected to the lower end of the reaction tank. The water inlet of the water pump communicates with the lower end of the three-phase separator, the water pump, the water distribution system and the lower part of the three-phase separator form a waste water internal circulation, and the upper end of the pulse water distributor is provided with a waste water inlet Shuikou. This technology has the following defects: 1. Wastewater circulation is not separated from sludge circulation, and the granular sludge formed is easily broken by the high-speed rotating water pump impeller. 2. Before the circulating water was collected, the biogas was not removed, and the cavitation of the water pump was serious, which greatly affected the service life of the water pump. 3. Sludge is easy to cause blockage in the pipeline and nozzle.

Contents of the invention

In view of the above technical problems, the present invention provides a circulating fluidized sludge bed (Circulation Fluidized Sludge Bed, CFSB for short) anaerobic reactor with high equipment utilization rate and good sewage treatment effect.

In order to achieve the above object, the technical solution adopted in the present invention is: a CFSB anaerobic reactor, comprising a reactor body, the inside of which is provided with an inner cylinder, a scum baffle, and a sump;

The upper and lower ends of the inner cylinder are open, and there is a gap between the inner cylinder and the reactor body, which is a sludge trap; the upper part of the inner cylinder is a conical constriction, and the top of the conical constriction is a water intake; under the face.

The scum baffle is arranged on the upper side of the water receiving port, and the scum baffle includes a lower baffle matching the shape of the conical constriction and an upper baffle matching the shape of the water receiving port; a circulating water outlet device is arranged on the outside of the scum baffle ; The upper part of the scum upper baffle is above the liquid level, and the lower part of the scum upper baffle is below the liquid level.

The upper part of the reactor body is the gas collection area, the water collection tank is below the gas collection area, and the top of the scum baffle is higher than the water collection tank;

The lower part of the reactor body is provided with an inverted conical mixing part; the lower part of the reactor body is also provided with a water inlet and a circulating water inlet device connected with the circulating water outlet device.

Further, the water outlet weir is arranged inside the water collection tank, and the upper part of the reactor body is provided with a water outlet connected with the water collection tank and the water outlet weir; the water inlet at the lower part of the reactor body is connected with the water inlet distributor arranged inside the inner cylinder.

Further, the circulating water outlet device includes a circulating water suction ring pipe arranged outside the upper baffle of the scum baffle, and a circulating water outlet connected to the circulating water suction ring pipe; the circulating water inlet device includes a circulating water inlet and a A circulating water distributor connected to the circulating water inlet.

Further, the circulating water inlet device is set in the mixing part, the spray holes on the circulating water distributor are set inside the inner cylinder, and the opening of the spray holes is downward, and the short pipes are nested in the spray holes, so as to facilitate the washing of the sludge deposited at the bottom . This design prevents the circulating return water from directly impacting the returning sludge. The opening of the water distributor pushes the deposited sludge downward to the mud hopper, and the rolled up part participates in the reaction and circulation of the inner cylinder.

Further, the inlet water distributor is arranged above the mixing part; both the inlet water distributor and the circulating water distributor are ring-shaped and arranged concentrically; the diameter of the inlet water distributor is smaller than the diameter of the circulating water distributor. The raw sewage at the water inlet is mixed and diluted with the circulating return water, and enters the reaction zone of the inner cylinder to contact with the sludge, thereby removing most of the organic matter.

Further, a gap is provided between the lower end of the inner cylinder and the mixing part at the lower part of the reactor body.

Further, a mud collecting bucket is connected to the lower end of the mixing part, and the bottom end of the mud collecting bucket is connected to a mud discharge port.

Further, the inner wall of the reactor body is also provided with a baffle fluid, and the baffle fluid is set at a height higher than the bottom end of the lower baffle of the scum baffle. The baffle is used to prevent the rising water from directly impacting the sump and the lower part of the outlet weir, forcing it to flow to the collection pipe of the circulating return water, and blowing off the sludge that may be deposited on the lower baffle.

Preferably, the baffle fluid is arranged around the inner wall of the reactor body, and the section of the baffle fluid is triangular; the height of the baffle fluid is the middle of the lower baffle plate of the scum baffle.

Further, the gas-gathering area at the top of the reactor includes a tapered slope, and the top of the gas-gathering area is provided with a gas outlet. The cone slope also acts as condensation, so the gas collection area is integrated with the air-water separator. The condensate flows along the inner wall of the cone slope at the top of the reactor, and flows into the sump by gravity, and is discharged together with the treated effluent. The biogas generated by the reactor body is collected in the gas-gathering area above the liquid-gas interface at the top, and after reaching a predetermined pressure, it is discharged to an external gas-water separator (determined whether to set it according to the specific situation), and then enters the biogas storage after desulfurization treatment. cabinet, and then sent to the point of use by the biogas fan. The condensed water generated in the biogas pipeline is discharged through the steam trap.

The invention has the following beneficial effects: 1. The inner cylinder is the reaction zone of the anaerobic reactor, and the volume of the reactor is almost equal to the volume of the reaction zone, so the utilization rate of the equipment is relatively high; in the reaction zone, the sludge presents a fluidized state , there is no short flow, the muddy water contact is good, and it is beneficial for material transfer.

2. This technical solution does not use a three-phase separator, so the problem of scum clogging in the traditional reactor can be avoided, and the rising flow rate is not affected and limited by the three-phase separator; the rising flow rate can be set according to ideal conditions, so it can Obtain relatively large volume loads. There is no opening between the upper edge of the inner cylinder and the tapered constriction, and the falling granular sludge is not affected by the rising water flow. The outer edge of the tapered constriction is welded flush with the inner cylinder, so there is no dead corner for gas collection and no corrosion. In addition, the technical solution also cancels the structure of the water-sealed tank.

3. There is no conflict in the flow of mud and water in this technical solution, and the sludge sedimentation efficiency is high; the setting of the sludge trap prevents the settled sludge from being carried up by the water flow twice, so it will not run out of mud; granular sludge It circulates inside the reactor without mechanical device drive and does not participate in the external circulation of sewage, so the granular sludge will not be damaged by the impeller of the circulating pump; and the circulating water does not contain granular sludge, so the circulating water nozzle will not clogged with sludge.

4. There is a water inlet device at the liquid-gas interface at the top, and the rising velocity of the water flow is higher, which is beneficial to inhibit the formation of the scum layer; even if there is scum, the scum baffle can limit the range of scum and facilitate the removal of scum .

5. The circulating water suction ring pipe is set above the lower baffle, and the sewage will not contain mud and air, so it is beneficial to the operation of the circulating water pump and prolongs the service life; the circulating water outlet is set on the top of the underwater cone, separated from the water outlet . The two have no influence on each other, so the sump and the outlet weir only collect and process the effluent, and the rising velocity of the water flow in the clarification area below it is very low, and the problem of effluent mud running is completely suppressed.

6. The raw water inlet and the circulating water inlet are separated into the bottom of the reactor, and short-tube jet annular water distributors are used for both. The raw water distributor is on the top, and the circulating water distributor is on the bottom. The nozzle of the circulating water distributor faces downward, which is convenient for washing the sludge deposited at the bottom. The circulating return water does not contain biogas, so the water pump impeller of the circulating return water will not be damaged by excessive cavitation.

7. The gas-gathering area at the top of the anaerobic reactor is integrated with the anaerobic reactor and integrated with the gas-water separator. There is no pipeline connection, there is no problem of condensed water air resistance, and the biogas is discharged smoothly. At the bottom of the anaerobic reactor, there is a sludge collection bucket for sludge collection, which is convenient for sludge discharge.

Description of drawings

Fig. 1 is a schematic structural diagram of a circulating fluidized sludge bed anaerobic reactor according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of the working process of the circulating fluidized sludge bed anaerobic reactor according to the embodiment of the present invention.

In the figure, 1 is the reactor body, 2 is the inner cylinder, 3 is the scum baffle, 4 is the sump and outlet weir, 5 is the gas collection area, 6 is the sludge trap, 7 is the conical constriction, 8 is the water inlet, 9 is the circulating water suction ring pipe, 10 is the retaining fluid, 11 is the mixing part, 12 is the water inlet, 13 is the circulating water inlet, 14 is the mud collecting bucket, 15 is the mud discharge port, and 16 is the sludge At the outlet end of the catcher, 17 is an air outlet, 18 is a water outlet, 19 is a circulating water outlet, 20 is a mud-water separation zone, 21 is an inlet water distributor, and 22 is a circulating water distributor.

Detailed ways

In order to facilitate the understanding of those skilled in the art, the present invention will be further described below in conjunction with the embodiments and accompanying drawings.

As shown in Figure 1, the structure of the circulating fluidized sludge bed (CFSB) anaerobic reactor of the present embodiment is as follows: comprising a reactor body 1, the inside of the reactor body 1 is provided with an inner cylinder 2, a scum baffle 3, a collector Water tank and outlet weir 4; the upper and lower ends of the inner cylinder 2 are open, and there is a gap between the inner cylinder 2 and the reactor body 1, which is a sludge trap 6; the upper part of the inner cylinder 2 is a conical contraction part 7, and the cone The top end of the shape contraction part 7 is the water receiving port 8.

The scum baffle 3 is arranged on the upper side of the water receiving port 8, and the scum baffle 3 includes a lower baffle matching the shape of the tapered constriction 7 and an upper baffle matching the shape of the water receiving port 8; The circulating water suction ring pipe 9 on the outside of the upper baffle plate, and the circulating water outlet 19 communicated with the circulating water suction ring pipe 9 . The area formed by the tapered constriction 7 , the lower baffle plate, the baffle body 10 and the like is the mud-water separation area 20 .

The upper part of the reactor body 1 is a gas collection area 5, and the top of the gas collection area 5 is connected to an external gas-water separator through an air outlet 17 (depending on the specific situation to determine whether to set it or not). The sump and outlet weir 4 are arranged below the gas gathering area 5, and the top of the scum baffle 3 is higher than the sump and outlet weir 4; the upper part of the reactor body 1 is provided with a water outlet 18 communicating with the sump and outlet weir 4 The inner wall of the reactor body 1 is also provided with a baffle fluid 10, the baffle fluid 10 is arranged around the inner wall of the reactor body 1, the baffle fluid 10 is formed by two plates, and the cross section is triangular; the setting height of the baffle fluid 10 is 3 the middle of the lower fender.

The lower part of the reactor body 1 is provided with an inverted tapered mixing part 11; a gap is provided between the lower end of the inner tube 2 and the mixing part 11. The lower end of the mixing part 11 is also connected with a mud collecting bucket 14 , and the bottom end of the mud collecting bucket 14 is connected with a mud discharge port 15 .

The lower part of the reactor body 1 is also provided with a water inlet 12 and a circulating water inlet 13 connected to a circulating water outlet 19 , and the circulating water inlet 13 is connected to a circulating water distributor 22 . The water inlet 12 communicates with the water inlet distributor 21 arranged inside the inner tube 2 . The water inlet distributor 21 is arranged above the mixing part 11 .

The circulating water inlet device is arranged in the mixing part 11, and the spray holes on the circulating water distributor 22 are set on the inside of the inner cylinder 2, and the openings of the spray holes are downward to facilitate the washing of the sludge deposited at the bottom.

The inlet water distributor 21 and the circulating water distributor 22 are both annular and concentrically arranged; the diameter of the inlet water distributor 21 is smaller than the diameter of the circulating water distributor 22 .

As shown in Figure 2, the working mode of the CFSB anaerobic reactor of the present embodiment is: 1, raw water (the sewage that water inlet enters) is transported to the mixing part 11 of reactor body 1 bottom by water inlet pump, here with circulating water and The sludge is mixed and then rises along the inner cylinder 2, which is the reaction zone of the anaerobic reactor. After the reaction is completed, the rising mixture rushes to the liquid-gas interface at a higher flow rate under the constraint of the water inlet 8, and the air bubbles attached to the surface of the granular sludge are thus removed.

2. The mud-water mixture after removing air bubbles passes over the upper edge of the water intake 8 and enters the mud-water separation zone under the constraint of the scum baffle 3 . In the mud-water separation zone, the mud-water flows in the same direction. During the flow process, the sludge settles to the bottom of the mud-water separation zone, and enters the sludge trap 6 under the force of gravity and water flow. The lower end of the inner cylinder 2 is the outlet end 16 of the sludge trap, where the captured sludge enters the mixing part 11 at the bottom of the reactor body 1, thereby completing the separation and reflux of the sludge. The returning sludge, returning circulating water and raw water are mixed at the mixing section 11. The purpose of mixing is to use the microorganisms in the sludge to degrade the organic pollutants in the raw sewage. The treated water leaves from the water outlet, and the sludge stays in the reactor body 1 to be mixed with the newly entered raw water. Repeatedly, so called cycle.

3. After separating the sludge liquid, under the joint action of the baffle fluid 10 and the lower baffle, it flows upwards to the diversion area, and most of the water flow will be collected by the circulating water suction pipe, and then pumped to the bottom of the reactor body 1 The mixing part 11 plays the role of diluting the raw water and pushing up the flow rate. The remaining very small part of the current will continue to rise to the sump and the outlet weir 4 outlets.

4. The biogas produced by the CFSB anaerobic reactor is collected in the gas-gathering area 5 above the liquid-gas interface at the top, and after reaching a predetermined pressure, it is discharged to an external gas-water separator (determined whether to set it according to the specific situation), and then undergoes desulfurization After treatment, it enters the biogas storage cabinet, and then is sent to the gas consumption point by the biogas fan. The condensed water generated in the biogas pipeline is discharged through the steam trap.

2. Features of CFSB Anaerobic Reactor

1. The volume of the reactor is almost equal to the volume of the reaction zone, so the utilization rate of the equipment is relatively high;

2. The ascending flow rate can be set according to ideal conditions, and a large ascending flow rate can increase the speed of biochemical reactions, so a relatively large volume load can be obtained;

3. In the reaction zone, the sludge is in a fluidized state, there is no short flow, and the mud-water contact is good, which is beneficial to material transfer;

4. No three-phase separator is used, so the problem of scum clogging can be avoided;

5. No three-phase separator is used, and the rising flow rate is not affected and limited by it;

6. No three-phase separator is used, so the water-sealed tank can be canceled;

7. There is no conflict in the flow direction of mud and water, and the sludge sedimentation efficiency is high;

8. Equipped with a sludge trap 6, the settled sludge will not be carried up by the water flow for a second time, so it will not run out of sludge;

9. Granular sludge circulates inside the reactor, without mechanical device driving, and does not participate in the external circulation of sewage, so granular sludge will not be damaged by the impeller of the circulating pump; the circulating pump is set outside the CFSB anaerobic reactor, both It can be arranged centrally in the pump room, or it can be arranged next to the reactor body 1 nearby. The inlet and outlet of the circulating water of the reactor body 1 of this embodiment are connected through pipelines, and flow meters, valves, elbows, tees and other pipe fittings are arranged on the pipelines as required.

10. Externally, only circulating water passes through the backflow cycle, and the circulating backwater does not contain sludge, and the circulating water nozzle of the circulating water distributor will not be blocked by sludge;

11. There is a water inlet 8 device at the top liquid-gas interface, and the rising velocity of the water flow is higher, which is beneficial to inhibit the formation of the scum layer;

12. There is a scum baffle 3 on the top to limit the range of scum and facilitate the removal of scum;

13. The circulating water suction pipe is set above the lower baffle, and there will be no mud and air in the sewage, so it is beneficial to the operation of the circulating water pump and prolongs the service life;

14. The sewage inflow and the circulating water inflow are separated into the bottom of the reactor, the circulating water inflow is at the bottom, and the sewage inflow is at the top;

15. The nozzle of the bottom circulating water distributor 22 faces downward, which is convenient for washing the sludge deposited at the bottom;

16. There is a mud collecting bucket 14 for collecting sludge at the bottom, which is convenient for sludge discharge.

The above embodiments are only to illustrate the technical ideas of the present invention, and cannot limit the scope of protection of the present invention with this. Any changes made on the basis of technical solutions according to the technical ideas proposed in the present invention all fall within the scope of protection of the present invention. within.

Claims (8)

1. An anaerobic reactor of a circulating fluidized sludge bed, which is characterized in that: comprises a reactor body, wherein an inner cylinder, a scum baffle plate and a water collecting tank are arranged in the reactor body;

the upper end and the lower end of the inner cylinder are open, a gap is arranged between the inner cylinder and the reactor body, and the gap is a sludge catcher; the upper part of the inner cylinder is a conical contraction part, and the top end of the conical contraction part is a water collecting port;

the scum baffle is arranged on the upper side of the water receiving opening and comprises a lower baffle matched with the shape of the conical shrinkage part and an upper baffle matched with the shape of the water receiving opening; the outer side of the scum baffle is provided with a circulating water outlet device;

the upper part of the reactor body is a gas collecting area, the water collecting tank is arranged below the gas collecting area, and the top of the scum baffle is higher than the water collecting tank;

the lower part of the reactor body is provided with an inverted cone-shaped mixing part; a gap is arranged between the lower end of the inner cylinder and the mixing part at the lower part of the reactor body; the lower part of the reactor body is also provided with a water inlet and a circulating water inlet device communicated with the circulating water outlet device;

the circulating water inlet device comprises a circulating water inlet and a circulating water distributor communicated with the circulating water inlet; the circulating water inlet device is arranged at the mixing part, the spray hole on the circulating water distributor is arranged at the inner side of the inner cylinder, the spray hole is downward, and a short pipe is nested at the spray hole.

2. The circulating fluidized sludge bed anaerobic reactor according to claim 1, wherein: the water outlet weir is arranged at the inner side of the water collecting tank, and the upper part of the reactor body is provided with a water outlet communicated with the water collecting tank and the water outlet weir; the water inlet at the lower part of the reactor body is communicated with a water inlet distributor arranged at the inner side of the inner cylinder.

3. The circulating fluidized sludge bed anaerobic reactor according to claim 1, wherein: the circulating water outlet device comprises a circulating water suction ring pipe arranged on the outer side of the upper baffle plate of the scum baffle plate and a circulating water outlet communicated with the circulating water suction ring pipe.

4. A circulating fluidized sludge bed anaerobic reactor according to claim 3, wherein: the water inlet at the lower part of the reactor body is communicated with a water inlet distributor arranged at the inner side of the inner cylinder; the water inlet and distribution device is arranged above the mixing part;

the water inlet water distributor and the circulating water distributor are annular and concentrically arranged; the diameter of the water inlet and distribution device is smaller than that of the circulating water distribution device.

5. The circulating fluidized sludge bed anaerobic reactor according to claim 1, wherein: the lower end of the mixing part is also connected with a sludge collecting hopper, and the bottom end of the sludge collecting hopper is connected with a sludge discharge port.

6. The circulating fluidized sludge bed anaerobic reactor according to claim 1, wherein: the inner wall of the reactor body is also provided with a baffle body, and the baffle body is arranged at the bottom end of the lower baffle plate with the height higher than that of the scum baffle plate.

7. The circulating fluidized sludge bed anaerobic reactor of claim 6, wherein: the baffle body is arranged around the inner wall of the reactor body, and the section of the baffle body is triangular; the setting height of baffle is the middle part of the lower baffle of dross baffle.

8. The circulating fluidized sludge bed anaerobic reactor according to claim 1, wherein: the gas collecting zone at the top end of the reactor comprises a slope surface in a cone shape, and the top of the gas collecting zone is provided with a gas outlet.

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