Flat plate slag scraping type superfine grid for sewage treatment and operation method of flat plate slag scraping type superfine grid

Abstract

The invention provides a flat slag scraping type superfine grid for sewage treatment and an operation method of the flat slag scraping type superfine grid, and belongs to the technical field of sewage treatment. The flat plate slag scraping type superfine grid comprises a grid body, a slag scraping system, a slag discharging system and an automatic control system, the automatic control system automatically adjusts the operation frequency of a driving motor by obtaining the liquid level difference delta of the water inlet end and the water outlet end of the grid body or according to the set starting time, then the slag scraping rate of the slag scraping system is adjusted, and the slag scraping rate of the slag discharging system is adjusted. Therefore, the sewage sand-slag separation effect is ensured. The flat slag scraping type superfine grid for sewage treatment can be used for separating and removing sand and slag in a pretreatment section, a biological treatment section, a sludge return section and an advanced treatment section of sewage treatment, and the interception and separation efficiency and the safe and stable operation capability of the superfine grid on inert substances can be greatly improved; the device can effectively cope with the impact influence of water quality and water quantity in peak drainage periods in dry seasons and flood seasons, and has the advantages of high impact resistance, good sand-slag separation effect and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular, relates to a flat slag scraping type ultra-fine grille for sewage treatment and an operation method thereof. Background Art

[0002] A grille is an important sand and slag interception and separation device in sewage treatment. Its main function is to separate and remove inert impurities such as particulate matters, hairs, and fibers in sewage. According to the grid pitch, it is generally divided into coarse grilles, fine grilles, ultra-fine grilles, etc., and plays an important guarantee role in the stable operation of the pretreatment unit, biological treatment unit, and advanced treatment unit. In recent years, with the continuous improvement of the effluent discharge standard of sewage treatment plants, due to the small effective area of the grid plates of traditional in-flow, drum and other pretreatment grilles, the removal effect of particulate matters and entanglements in the influent water is not ideal, and the operation modes of grid plate drive and hydraulic slag flushing also bring problems of high power consumption and high water consumption. In particular, the poor interception and separation effect leads to a large amount of particulate matters, fibers, hairs, etc. entering the subsequent biological treatment and advanced treatment units, not only reducing the operation efficiency of the biological treatment unit and advanced treatment unit, but also seriously affecting the long-term stable operation of facilities and equipment such as lift pumps and agitators, and the treatment power consumption, material consumption, and labor costs also increase significantly. In addition, it is found in actual engineering practice that the fluctuations in the water volume and water quality of the influent water of sewage treatment facilities, especially the sudden increase in suspended solids and water volume during the flood season, pose certain challenges to the efficient and stable operation of the grille. The above actual problems have put forward higher requirements for the operation performance, installation position, and operation mode of the grille.

[0003] Therefore, it is necessary to study and break through the structure, operation mode, installation mode, etc. of the grille, especially the ultra-fine grille, to provide a brand-new ultra-fine grille and its operation method, to cope with the impact under different operation load conditions, and to solve the problems of the influence of inorganic substances such as particulate matters, fibers, and hairs in different treatment units on the operation efficiency and normal operation of equipment, so as to ensure the long-term efficient, safe, and stable operation of sewage treatment facilities. Summary of the Invention

[0004] The object of the present invention is to overcome and supplement the deficiencies existing in the prior art, and to provide a flat slag scraping type ultra-fine grille for sewage treatment and its operation method. The flat slag scraping type ultra-fine grille of the present invention includes a grille main body, a slag scraping system, a slag discharging system and an automatic control system, and can be used in the pre-treatment section, biological treatment section, return sludge section and advanced treatment section of sewage treatment facilities in an on-line and bypass manner for the separation and removal of sand and slag. The automatic control system can automatically adjust the slag scraping rate of the slag scraping system through the liquid level difference at the water inlet end and the water outlet end of the grille or at regular intervals to ensure the sewage sand and slag separation effect. The present invention effectively improves the interception and separation efficiency of the ultra-fine grille for inert substances such as particulate matter and filamentous substances and the safe and stable operation ability, has a flexible installation position, can effectively cope with the impact of peak drainage periods in the dry season and the water quality and quantity during the flood season, and has the advantages of strong impact resistance and good sand and slag separation effect.

[0005] To achieve the above technical objectives, the technical solutions adopted in the embodiments of the present invention are as follows: In the first aspect, an embodiment of the present invention provides a flat slag scraping type ultra-fine grille for sewage treatment, including a grille main body, a slag scraping system, a slag discharging system and an automatic control system; The grille main body includes a flat grille plate, the flat grille plate is arranged on the support keel at an angle of ≤ 15°, the support keel is arranged on the support frame, vertical baffles with overflow ports are arranged on both sides of the flat grille plate, one end of the flat grille plate is connected to the water inlet diversion plate, and the other end is connected to the slag guiding plate. The lower part of the slag guiding plate is a perforated plate structure, and a water guiding plate is arranged on the back of the slag guiding plate for guiding the sewage passing through the slag guiding plate to the water outlet end; The slag scraping system includes a driving motor, the driving motor drives a chain to rotate reciprocally in the guide rail through a driving shaft, a first driven shaft and a second driven shaft. The chain is arranged on both sides of the grille main body, the guide rail is arranged on the vertical baffle, and a slag scraping assembly is arranged on the chain. The slag scraping assembly is used to push the intercepted substances on the flat grille plate to the slag guiding plate and enter the slag discharging system through the slag guiding plate; The automatic control system automatically adjusts the operating frequency of the driving motor through the liquid level difference δ at the water inlet end and the water outlet end of the grille main body or according to the set start time, and further adjusts the slag scraping rate of the slag scraping system.

[0006] Further, the included angle α between the water inlet diversion plate and the flat grille plate is 105° - 150°, the water inlet diversion plate is movably connected to the flat grille plate, and the connection part is such that the flat grille plate is above and the water inlet diversion plate is below; The flat grille plate is a circular perforated plate structure made of stainless steel, the aperture of the opening is 0.2 - 6 mm, the opening ratio is 20% - 45%, the thickness is 1 - 5 mm, the length is 1 - 6 m, and the width is 5 - 30 cm smaller than the width of the installation space.

[0007] Further, the included angle β between the slag guide plate and the planar grid plate is 30° to 75°, and the width and thickness of the slag guide plate are the same as those of the planar grid plate; The perforated part of the slag guide plate is located 0.5 to 1.5 m above the connection with the planar grid plate, the pore diameter of the perforation is not larger than that of the planar grid plate, and the installation height of the water diversion plate is not lower than the topmost part of the perforated area of the slag guide plate.

[0008] Further, the overflow port is arranged at the middle position above the vertical baffle, with a length of 1 to 2 m, a height of 5 to 20 cm, and the vertical distance from the bottom of the overflow port to the planar grid plate is 10 to 30 cm.

[0009] Further, reserved installation card slots for slag scraping brackets are arranged on the chain at intervals of 0.5 to 1 m. The two ends of the slag scraping brackets are fixed on the outer side of the chain, and the installation spacing between adjacent slag scraping brackets is 0.5 to 1.5 m. A movable slag scraping assembly is arranged on the slag scraping brackets. The slag scraping assembly includes scrapers and brushes arranged at intervals, and the setting ratio of the scrapers to the brushes is 2:1 to 10:1.

[0010] Further, the support keel is a steel structure frame in the shape of a Chinese character "tian" or fishbone, which is fixedly connected to the back of the planar grid plate, and is in direct contact with the bottom of the installation position. The contact area with the planar grid plate does not exceed 5% of the area of the planar grid plate.

[0011] Further, the slag discharging system includes a high-drainage pressing tank. A vertically downward slag discharging port is arranged on the high-drainage pressing tank. A pressing screw is arranged in the high-drainage pressing tank. The pressing screw is driven by a pressing motor, and the power of the pressing motor is 0.75 to 1.5 kW·h. Drainage holes are uniformly arranged on the drainage side of the high-drainage pressing tank, and brushes are arranged on the pressing screw.

[0012] In a second aspect, an embodiment of the present invention provides an operation method for the flat slag scraping type ultra-fine grille for sewage treatment described in the first aspect, including the following steps: Step S1: Sewage flows to the planar grid plate through the water inlet diversion plate at the water inlet end. Impurities including particulate matters and filaments in the sewage are intercepted on the planar grid plate under the filtering action of the planar grid plate. The separated sewage enters the water outlet end downward under the action of gravity and inertia. The driving motor drives the chain and the slag scraping assembly arranged thereon to rotate reciprocally at a low gear through the driving shaft, the first driven shaft and the second driven shaft, scrapes off the particulate matters and filaments intercepted on the planar grid plate, and brings them into the high-drainage pressing tank through the slag guide plate. Under the action of the pressing screw, the moisture content is reduced, and it is gradually pressed out of the slag discharging port and then transported out. The sewage carried by the slag scraping assembly is diverted to the water outlet end by the water diversion plate through the orifice structure of the slag guide plate. At this time, the liquid level difference δ between the water inlet end and the water outlet end of the grille main body is ≤ 10 cm; Step S2: When the water inflow increases or the concentration of suspended matter including particulate matter and filamentous matter in the influent water increases, the liquid level difference between the water inlet end and the water outlet end of the grille body gradually increases. When the liquid level difference varies within the range of 10 cm < δ ≤ 20 cm and the duration exceeds 10 minutes, the automatic control system adjusts the operating power of the drive motor to high gear operation; Step S3: When the liquid level difference between the water inlet end and the water outlet end of the grille body drops to within the range of δ ≤ 10 cm and the duration exceeds 30 minutes, the automatic control system adjusts the operating power of the drive motor to low gear operation, and the slag scraping rate of the slag scraping system decreases; Step S4: Steps S1 - S3 are alternately operated in a cycle, where the operating frequency of the drive motor in low gear is: 10 Hz < f ≤ 30 Hz, and the operating frequency in high gear is: 30 Hz < f ≤ 50 Hz.

[0013] In a third aspect, an embodiment of the present invention provides an operation method for the flat slag scraping type ultra - fine grille for sewage treatment described in the first aspect, including the following steps: Step 1: According to the 24 - hour water inflow change curve of the sewage treatment facility in the recent 30 days, analyze and determine the time periods T1, T2, T3, …, T n in a day of 24 hours that exceed the average hourly flow rate and the time periods t1, t2, t3, …, t m that are not higher than the average hourly flow rate; Step 2: Set, through the automatic control system, the operating power of the drive motor to be in high gear during the time periods T1, T2, T3, …, T n and in low gear during the time periods t1, t2, t3, …, t m ; Step 3: Start the flat slag scraping type ultra - fine grille for sewage treatment. When in the time periods T1, T2, T3, …, T n in a day, the water inflow exceeds the average hourly flow rate, the suspended matter including particulate matter and filamentous matter intercepted increases, and the slag scraping demand increases. The automatic control system automatically adjusts the drive motor to operate in high gear; when entering the time periods t1, t2, t3, …, t m , the water inflow drops to a level not higher than the average hourly flow rate, the suspended matter including particulate matter and filamentous matter intercepted decreases, and the slag scraping demand decreases. The automatic control system automatically switches the drive motor to low gear operation again; Step 4: Step 3 is operated in a cycle or steps 1 - 3 are operated in a cycle, where the operating frequency of the drive motor in low gear is: 10Hz < f ≤ 30Hz, and the operating frequency in high gear is: 30Hz < f≤50Hz.

[0014] Further, when the water inflow exceeds 1.5 times the designed treatment capacity of the flat slag scraping type ultra - fine grille or other failures cause the flat slag scraping type ultra - fine grille to stop operating, the sewage overflows through the overflow port and enters the water outlet end.

[0015] The beneficial effects brought by the technical solution provided by the embodiment of the present invention are as follows: (1) Through the design of the grille main body, slag scraping system, slag discharging system and automatic control system, the present invention greatly increases the contact area between the grille plate and the sewage, effectively improves the interception and separation efficiency of inert substances such as particulate matter and filamentous substances, can be directly installed behind the coarse grille, completely changes the traditional grille configuration method of "coarse - fine - ultra - fine", and changes the design method of ultra - fine grille with high power consumption and high water consumption for grille plate drive and hydraulic slag flushing.

[0016] (2) The installation position of the present invention is flexible. It can be installed in the pretreatment section, biological treatment section, return sludge section, and advanced treatment section according to the current space conditions and treatment requirements of the sewage treatment facilities, and can be designed as an online treatment or bypass treatment mode, effectively solving the problem of limited land occupation in the new construction and renovation projects of sewage treatment facilities.

[0017] (3) The present invention automatically adjusts the slag scraping rate of the slag scraping system through the automatic control system, effectively solves the impact of peak drainage periods in dry seasons and the impact of water quality and quantity during flood seasons, and at the same time solves the operation safety problems during overload operation and fault shutdown through the design of the overflow port and other components. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the front view of the flat slag scraping type ultra - fine grille for sewage treatment in the embodiment of the present invention.

[0019] Figure 2 It is the top view of the flat slag scraping type ultra - fine grille for sewage treatment in the embodiment of the present invention.

[0020] Figure 3 It is the schematic diagram of the slag scraping support of the flat slag scraping type ultra - fine grille for sewage treatment in the embodiment of the present invention.

[0021] Figure 4 It is the schematic diagram of the cross - shaped support keel of the flat slag scraping type ultra - fine grille for sewage treatment in the embodiment of the present invention.

[0022] Figure 5 It is the schematic diagram of the fish - bone - shaped support keel of the flat slag scraping type ultra - fine grille for sewage treatment in the embodiment of the present invention.

[0023] Figure 6 It is the structural schematic diagram of the online installation mode of the flat slag scraping type ultra - fine grille for sewage treatment in the embodiment of the present invention.

[0024] Figure 7 This is a schematic structural diagram of the bypass installation mode of the flat slag scraping type ultra-fine grille for sewage treatment in the embodiments of the present invention.

[0025] Explanation of reference numerals: 1 - grille main body; 2 - slag scraping system; 3 - slag discharging system; 4 - automatic control system; 11 - water inlet diversion plate; 12 - flat grille plate; 13 - slag guiding plate; 14 - vertical baffle; 15 - overflow port; 16 - water diversion plate; 17 - support keel; 18 - support frame; 21 - chain; 22 - driving shaft; 23 - first driven shaft; 24 - second driven shaft; 25 - guide rail; 26 - driving motor; 27 - slag scraping bracket; 28 - scraper; 29 - brush; 31 - high drainage pressing tank; 32 - pressing screw; 33 - pressing motor; 34 - slag discharging port. Specific embodiments

[0026] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "inside, outside", "above, below", "left, right", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention.

[0027] A flat slag scraping type ultra-fine grille for sewage treatment includes a grille main body 1, a slag scraping system 2, a slag discharging system 3 and an automatic control system 4; The grille main body 1 includes a water inlet diversion plate 11, a flat grille plate 12, a slag guiding plate 13, a vertical baffle 14, an overflow port 15, a water diversion plate 16, a support keel 17 and a support frame 18; The flat grille plate 12 is arranged on the support keel 17 at an angle of ≤ 15°. The support keel 17 is arranged on the support frame 18. Vertical baffles 14 with overflow ports 15 are arranged on both sides of the flat grille plate 12. One end of the flat grille plate 12 is connected to the water inlet diversion plate 11, and the other end is connected to the slag guiding plate 13. The lower part of the slag guiding plate 13 is a perforated plate structure, and a water diversion plate 16 is arranged on the back of the slag guiding plate 13 for diverting the sewage passing through the slag guiding plate 13 to the water outlet end; The included angle α between the water inlet diversion plate 11 and the flat grille plate 12 is 105° - 150°. The water inlet diversion plate 11 is movably connected to the flat grille plate 12, and at the connection, the flat grille plate 12 is above and the water inlet diversion plate 11 is below; the water inlet diversion plate 11 is fixed at the water inlet end and is hermetically connected to the side wall of the water inlet end or the vertical baffle 14. Sewage enters the grille main body 1 through the water inlet diversion plate 11 at a flow rate of not less than 1.0 m / s.

[0028] The planar grid plate 12 is a circular perforated plate structure made of stainless steel, with the aperture of the openings being 0.2 - 6 mm, the opening ratio being 20% - 45%, the thickness being 1 - 5 mm, the length being 1 - 6 m, and the width being 5 - 30 cm smaller than the width of the installation space.

[0029] The included angle β between the slag guiding plate 13 and the planar grid plate 12 is 30° - 75°, and the width and thickness of the slag guiding plate 13 are the same as those of the planar grid plate 12; The perforated part of the slag guiding plate 13 is located 0.5 - 1.5 m above the connection with the planar grid plate 12, the aperture of the openings is not larger than that of the planar grid plate 12, and the installation height of the water diversion plate 16 is not lower than the topmost part of the perforated area of the slag guiding plate 13.

[0030] The overflow port 15 is arranged at the middle position above the vertical baffle 14, with a length of 1 - 2 m, a height of 5 - 20 cm, and the vertical distance from the bottom of the overflow port 15 to the planar grid plate 12 is 10 - 30 cm.

[0031] See Figure 4 and 5 As shown, the support keel 17 is a steel structure frame in the shape of a Chinese character 'tian' or fishbone, fixedly connected to the back of the planar grid plate 12, and in direct contact with the bottom of the installation position, and the contact area with the planar grid plate 12 does not exceed 5% of the area of the planar grid plate 12.

[0032] The slag scraping system 2 includes a chain 21, a driving shaft 22, a first driven shaft 23, a second driven shaft 24, a guide rail 25, a driving motor 26, a slag scraping bracket 27, and a slag scraping assembly; The driving motor 26 drives the chain 21 to rotate reciprocally in the guide rail 25 through the driving shaft 22, the first driven shaft 23, and the second driven shaft 24. The chain 21 is arranged on both sides of the grille main body 1, the guide rail 25 is arranged on the vertical baffle 14, and a slag scraping assembly is arranged on the chain 21. The slag scraping assembly is used to push the intercepted substances on the planar grid plate 12 towards the slag guiding plate 13 and enter the slag discharging system 3 through the slag guiding plate 13; Reserved installation slots for the slag scraping bracket 27 are arranged on the chain 21 at intervals of 0.5 - 1 m. Both ends of the slag scraping bracket 27 are fixed on the outer side of the chain 21, the installation spacing between adjacent slag scraping brackets 27 is 0.5 - 1.5 m, and a movably connected slag scraping assembly is arranged on the slag scraping bracket 27. The slag scraping assembly includes a scraper 28 and a brush 29 arranged at intervals, and the setting ratio of the scraper 28 to the brush 29 is 2:1 - 10:1. The scraper 28 is made of wear-resistant material. The reciprocating movement of the chain 21 in the guide rail 25 can prevent the chain from derailing and winding with filaments, fibers, etc.

[0033] The slag discharging system 3 includes a high - drainage pressing trough 31, a pressing screw 32, a pressing motor 33, and a slag discharging port 34; The high-drainage pressing tank 31 is provided with a slag discharge port 34 facing vertically downward. A pressing screw 32 is arranged inside the high-drainage pressing tank 31. The pressing screw 32 is driven by a pressing motor 33, and the power of the pressing motor 33 is 0.75 - 1.5 kW·h. Drainage holes are evenly arranged on the drainage side of the high-drainage pressing tank 31, and a brush is arranged on the pressing screw 32.

[0034] The automatic control system 4 automatically adjusts the operating frequency of the driving motor 26 through the liquid level difference δ at the water inlet end and the water outlet end of the grille main body 1 or according to the set start-up time, and then adjusts the slag scraping rate of the slag scraping system 2.

[0035] The installation positions of the flat slag scraping type ultra-fine grille for sewage treatment include but are not limited to the pretreatment section, biological treatment section, return sludge section, and advanced treatment section of sewage treatment facilities, and can be designed as an in-line treatment or bypass treatment mode according to the current conditions of the facilities and treatment needs.

[0036] In order to cope with the fluctuations in the water quality and quantity of the influent in the dry season and flood season, the operation method of the above-mentioned flat slag scraping type ultra-fine grille for sewage treatment includes the following steps: Step S1: Sewage flows through the water inlet guide plate 11 at the water inlet end to the flat grille plate 12. Impurities including particulate matter and filamentous matter in the sewage are intercepted on the flat grille plate 12 under the filtering action of the flat grille plate 12. The separated sewage enters the water outlet end downward under the action of gravity and inertia. The driving motor 26 drives the chain 21 and the slag scraping assembly thereon to reciprocate at a low gear (operating frequency: 10Hz < f ≤ 30Hz) through the driving shaft 22, the first driven shaft 23, and the second driven shaft 24, scraping off the particulate matter and filamentous matter on the flat grille plate 12 and bringing them into the high-drainage pressing tank 31 through the slag guide plate 13. Under the action of the pressing screw 32, the moisture content is reduced, and it is gradually pressed out of the slag discharge port 34 and then transported out. The sewage carried by the slag scraping assembly is drained to the water outlet end by the water diversion plate 16 through the orifice plate structure of the slag guide plate 13. At this time, the liquid level difference δ between the water inlet end and the water outlet end of the grille main body 1 ≤ 10cm; Step S2: When the influent volume increases or the concentration of suspended matter including particulate matter and filamentous matter in the influent increases, since the slag scraping system 2 cannot meet the slag scraping requirements under this influent load condition, the liquid level difference between the water inlet end and the water outlet end of the grille main body 1 gradually increases. When the liquid level difference changes within the range of 10cm < δ ≤ 20cm and the duration exceeds 10min, the automatic control system 4 adjusts the operating power of the driving motor 26 to a high gear (operating frequency: 30Hz < f ≤ 50Hz) for operation, the slag scraping rate of the slag scraping system 2 is increased, the efficiency of scraping and pressing out the particulate matter and filamentous matter on the flat grille plate 12 is increased, and the liquid level difference data between the water inlet end and the water outlet end gradually decreases; Step S3: When the liquid level difference between the water inlet end and the water outlet end of the grille main body 1 drops to within the range of δ ≤ 10 cm and lasts for more than 30 minutes, the automatic control system 4 adjusts the operating power of the drive motor 26 to the low gear (operating frequency: 10 Hz < f ≤ 30 Hz) for operation, and the slag scraping rate of the slag scraping system 2 decreases; Step S4: Steps S1 - S3 run in an alternating cycle.

[0037] When the water inflow exceeds 1.5 times the designed treatment capacity of the flat slag scraping type ultra - fine grille or other failures cause the flat slag scraping type ultra - fine grille to stop operating, the sewage overflows into the water outlet end through the overflow port 15 to ensure the safe operation of the sewage treatment facility.

[0038] To cope with the water inflow fluctuations in the dry season, the operation method of the above - mentioned flat slag scraping type ultra - fine grille for sewage treatment includes the following steps: Step 1: According to the 24 - hour water inflow change curve of the sewage treatment facility in the recent 30 days, analyze and determine the time periods T1, T2, T3, …, T n in a day of 24 hours that exceed the average hourly flow rate and the time periods t1, t2, t3, …, t m that are not higher than the average hourly flow rate; Step 2: Through the automatic control system 4, set the operating power of the drive motor 26 at the high gear (operating frequency: 30 Hz < n ≤ 50 Hz) during the time periods T1, T2, T3, …, T f and at the low gear (operating frequency: 10 Hz < m ≤ 30 Hz) during the time periods t1, t2, t3, …, t f ; Step 3: Start the flat slag scraping type ultra - fine grille for sewage treatment. When in the time periods T1, T2, T3, …, T n of a day, the water inflow exceeds the average hourly flow rate, the intercepted suspended matters such as particulate matters and filamentous substances increase, and the slag scraping demand increases. The automatic control system 4 automatically adjusts the drive motor 26 to operate at the high gear (operating frequency: 30 Hz < f ≤ 50 Hz); when entering the time periods t1, t2, t3, …, t m , the water inflow drops to a level not higher than the average hourly flow rate, the intercepted suspended matters such as particulate matters and filamentous substances decrease, and the slag scraping demand decreases. The automatic control system 4 automatically switches the drive motor 26 to the low gear (operating frequency: 10 Hz < f ≤ 30 Hz) for operation; Step 4: Step 3 runs in a cycle or steps 1 - 3 run in a cycle; When the water inflow exceeds 1.5 times the designed treatment capacity of the flat slag scraping type ultra - fine grille or other failures cause the flat slag scraping type ultra - fine grille to stop operating, the sewage overflows into the water outlet end through the overflow port 15 to ensure the safe operation of the sewage treatment facilities.

[0039] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] Embodiment 1 As Figures 1 - 3 shown, a flat slag scraping type ultra - fine grille for sewage treatment is used in the pre - treatment renovation project of a sewage treatment plant. It is installed online after the coarse grille and before the aerated grit chamber in the pre - treatment section. As Figure 6 shown, it directly replaces the original 3 - mm toothed rake fine grille in the plant, forming a new gradation of 15 - mm coarse grille + 2 - mm ultra - fine grille.

[0041] The flat slag scraping type ultra - fine grille for sewage treatment includes a grille main body 1, a slag scraping system 2, a slag discharging system 3 and an automatic control system 4; The grille main body 1 includes an inlet flow - guiding plate 11, a flat grid plate 12, a slag guiding plate 13, a vertical baffle 14, an overflow port 15, a water - guiding plate 16, a support keel 17 and a support frame 18; The flat grid plate 12 is horizontally arranged on the support keel 17, the support keel 17 is arranged on the support frame 18. Vertical baffles 14 with overflow ports 15 are arranged on both sides of the flat grid plate 12. One end of the flat grid plate 12 is connected to the inlet flow - guiding plate 11, and the other end is connected to the slag guiding plate 13. The lower part of the slag guiding plate 13 is a perforated plate structure, and a water - guiding plate 16 is arranged on the back of the slag guiding plate 13 to divert the sewage passing through the slag guiding plate 13 to the water outlet end; The included angle α between the inlet flow - guiding plate 11 and the flat grid plate 12 is 120°. The inlet flow - guiding plate 11 is movably connected to the flat grid plate 12, and at the connection, the flat grid plate 12 is on the top and the inlet flow - guiding plate 11 is at the bottom. The inlet flow - guiding plate 11 is fixed at the inlet end and is hermetically connected to the side wall of the inlet end. The sewage enters the grille main body 1 through the inlet flow - guiding plate 11 at a flow rate of not less than 1.0 m / s.

[0042] The flat grid plate 12 is a circular perforated plate structure made of stainless steel, with a hole diameter of 2 mm, an opening ratio of 35%, a thickness of 2 mm, a length of 4 m, and a width 20 cm smaller than the width of the installation space.

[0043] The included angle β between the slag guiding plate 13 and the flat grid plate 12 is 30°. The width and thickness of the slag guiding plate 13 are the same as those of the flat grid plate 12; The perforated part of the slag guide plate 13 is located 0.5 m above the connection with the flat grid plate 12, the aperture of the perforation is not larger than that of the flat grid plate 12, and the installation height of the water diversion plate 16 is not lower than the top of the perforated area of the slag guide plate 13.

[0044] The overflow port 15 is arranged at the middle position above the vertical baffle 14, with a length of 1.5 m, a height of 20 cm, and the vertical distance from the bottom of the overflow port 15 to the flat grid plate 12 is 10 cm.

[0045] As Figure 4 shown, the support keel 17 is a steel structure frame in the shape of a Chinese character "tian", fixedly connected to the back of the flat grid plate 12, and directly contacting the bottom of the installation position, and the contact area with the flat grid plate 12 is 3% of the area of the flat grid plate 12.

[0046] The slag scraping system 2 includes a chain 21, a driving shaft 22, a first driven shaft 23, a second driven shaft 24, a guide rail 25, a driving motor 26, a slag scraping bracket 27 and a slag scraping assembly; The driving motor 26 drives the chain 21 to reciprocate in the guide rail 25 through the driving shaft 22, the first driven shaft 23 and the second driven shaft 24. The chain 21 is arranged on both sides of the grille main body 1, the guide rail 25 is arranged on the vertical baffle 14, and a slag scraping assembly is arranged on the chain 21. The slag scraping assembly is used to push the intercepted substances on the flat grid plate 12 to the slag guide plate 13 and enter the slag discharging system 3 through the slag guide plate 13; A reserved installation slot for the slag scraping bracket 27 is arranged on the chain 21 at an interval of 0.6 m. Both ends of the slag scraping bracket 27 are fixed on the outside of the chain 21, the installation distance between adjacent slag scraping brackets 27 is 1.2 m, and a movably connected slag scraping assembly is arranged on the slag scraping bracket 27. The slag scraping assembly includes a scraper 28 and a brush 29 arranged at intervals, and the setting ratio of the scraper 28 to the brush 29 is 6:1. The reciprocating movement of the chain 21 in the guide rail 25 can prevent the chain from derailing and winding of filaments, fibers, etc.

[0047] The slag discharging system 3 includes a high-drainage pressing tank 31, a pressing screw 32, a pressing motor 33 and a slag discharging port 34; A vertically downward slag discharging port 34 is arranged on the high-drainage pressing tank 31. A pressing screw 32 is arranged in the high-drainage pressing tank 31. The pressing screw 32 is driven by the pressing motor 33. The power of the pressing motor 33 is 1.5 kW·h. Drainage holes are evenly arranged on the drainage side of the high-drainage pressing tank 31, and a brush is arranged on the pressing screw 32.

[0048] The automatic control system 4 automatically adjusts the operating frequency of the driving motor 26 according to the liquid level difference δ of the liquid level gauges arranged at the water inlet end and the water outlet end of the grille main body 1, and further adjusts the slag scraping rate of the slag scraping system 2.

[0049] The operation method of the above-mentioned flat plate slag scraping type ultra-fine grille includes the following steps: Step S1: The sewage flows through the inlet end water inlet guide plate 11 to the planar grid plate 12. Impurities in the sewage, including particulate matters and filaments, are intercepted above the planar grid plate 12 under the filtering action of the planar grid plate 12. The separated sewage enters the outlet end downward under the action of gravity and inertia. The driving motor 26 drives the slag scraping assembly on the chain 21 to rotate reciprocally at a low gear (operating frequency: 10 Hz < f ≤ 30 Hz) through the driving shaft 22, the first driven shaft 23, and the second driven shaft 24, scraping off the particulate matters and filaments above the planar grid plate 12 and bringing them into the high-drainage pressing tank 31 through the slag guide plate 13. Under the action of the pressing screw 32, the moisture content is reduced, and they are gradually pressed out of the slag outlet 34 and transported out. The sewage on the slag scraping assembly is diverted to the outlet end by the water diversion plate 16 through the orifice plate structure of the slag guide plate 13. At this time, the liquid level difference δ between the inlet end and the outlet end of the grille main body 1 is ≤ 10 cm; Step S2: When the water inflow increases or the concentration of suspended matters, including particulate matters and filaments, in the influent water increases, the slag scraping system 2 cannot meet the slag scraping demand under this influent load condition, resulting in a gradual increase in the liquid level difference between the inlet end and the outlet end of the grille main body 1. When the liquid level difference varies within the range of 10 cm < δ ≤ 20 cm and the duration exceeds 10 min, the automatic control system 4 adjusts the operating power of the driving motor 26 to a high gear (operating frequency: 30 Hz < f ≤ 50 Hz) for operation. The slag scraping rate of the slag scraping system 2 is increased, and the efficiency of scraping off and pressing out the particulate matters and filaments above the planar grid plate 12 is increased. The liquid level difference data between the inlet end and the outlet end gradually decreases; Step S3: When the liquid level difference between the inlet end and the outlet end of the grille main body 1 drops to within the range of δ ≤ 10 cm and the duration exceeds 30 min, the automatic control system 4 adjusts the operating power of the driving motor 26 to a low gear (operating frequency: 10 Hz < f ≤ 30 Hz) for operation, and the slag scraping rate of the slag scraping system 2 is reduced; Step S4: Steps S1 - S3 are alternately operated in a cycle.

[0050] When the water inflow exceeds 1.5 times the designed treatment capacity of the flat slag scraping type ultra-fine grille or other faults cause the flat slag scraping type ultra-fine grille to stop operating, the sewage overflows into the outlet end through the overflow port 15 to ensure the safe operation of the sewage treatment facility.

[0051] Compared with the original 3mm toothed rake fine grille, without changing the original water inlet channel, the treatment capacity of this flat slag scraping ultra-fine grille has been directly increased from 30,000 tons per day to 60,000 tons per day, with the treatment scale increased by 100%. Under the same treatment capacity, the amount of grid slag intercepted and removed is 4 to 5 times that of the original fine grille. The content of inorganic suspended matter in the subsequent biological treatment unit and advanced treatment unit has been significantly reduced, the manual slag removal workload has been reduced by 90%, and the number of repairs of the magnetic coagulation reflux pump has been reduced from the original 10 - 15 times per month to 1 - 2 times per month.

[0052] Example 2 A flat slag scraping ultra-fine grille for sewage treatment is used to intercept, separate and remove inorganic inert substances such as particulate matter and filamentous substances in the biological pool of a sewage treatment plant. It is installed near the biological pool in a bypass manner, as shown in Figure 7 shown. The influent comes from the influent end of the aerobic section of the biological pool and is lifted into the flat slag scraping ultra-fine grille for sewage treatment by a lift pump, and the effluent is discharged by gravity flow into the effluent end of the aerobic section of the biological pool.

[0053] The flat slag scraping ultra-fine grille for sewage treatment includes a grille main body 1, a slag scraping system 2, a slag discharging system 3 and an automatic control system 4; The grille main body 1 includes an influent guide plate 11, a flat grid plate 12, a slag guide plate 13, a vertical baffle 14, an overflow port 15, a water diversion plate 16, a support keel 17 and a support frame 18; The flat grid plate 12 is arranged at a 5° angle on the support keel 17. The support keel 17 is arranged on the support frame 18. Vertical baffles 14 with overflow ports 15 are arranged on both sides of the flat grid plate 12. One end of the flat grid plate 12 is connected to the influent guide plate 11, and the other end is connected to the slag guide plate 13. The lower part of the slag guide plate 13 is a perforated plate structure, and a water diversion plate 16 is arranged on the back of the slag guide plate 13 to divert the sewage passing through the slag guide plate 13 to the effluent end; Supports are arranged below the connection between both sides of the flat grid plate 12 and the slag guide plate 13. The top of the support is connected to the flat grid plate 12, and the bottom is connected to the support keel 17. The included angle α between the influent guide plate 11 and the flat grid plate 12 is 150°. The influent guide plate 11 is movably connected to the flat grid plate 12, and at the connection, the flat grid plate 12 is on the top and the influent guide plate 11 is on the bottom. The influent guide plate 11 is fixed at the influent end and is hermetically connected to the vertical baffle 14. The sewage enters the grille main body 1 through the influent guide plate 11 at a flow rate of not less than 1.0 m / s.

[0054] The flat grid plate 12 is a circular perforated plate structure made of stainless steel, with a hole diameter of 1 mm, an opening ratio of 30%, a thickness of 1 mm, a length of 2 m, a width of 1 m, and is 30 cm smaller than the width of the installation space.

[0055] The included angle β between the slag guide plate 13 and the flat grid plate 12 is 45°. The width and thickness of the slag guide plate 13 are the same as those of the flat grid plate 12; The perforated part of the slag guide plate 13 is located 0.5 m above the connection with the flat grid plate 12, and the aperture of the perforation is the same as that of the flat grid plate 12. The installation height of the water diversion plate 16 is not lower than the topmost part of the perforated area of the slag guide plate 13.

[0056] The overflow port 15 is arranged at the middle position above the vertical baffle 14, with a length of 0.5 m and a height of 8 cm. The vertical distance from the bottom of the overflow port 15 to the flat grid plate 12 is 10 cm, and the overflow water directly enters the biological pond.

[0057] As Figure 5 shown, the support keel 17 is a fishbone-shaped steel structure frame, fixedly connected to the back of the flat grid plate 12, and in direct contact with the bottom of the installation position, and the contact area with the flat grid plate 12 is 5% of the area of the flat grid plate 12.

[0058] The slag scraping system 2 includes a chain 21, a driving shaft 22, a first driven shaft 23, a second driven shaft 24, a guide rail 25, a driving motor 26, a slag scraping bracket 27 and a slag scraping assembly; The driving motor 26 drives the chain 21 to reciprocate in the guide rail 25 through the driving shaft 22, the first driven shaft 23 and the second driven shaft 24. The chain 21 is arranged on both sides of the grille main body 1, the guide rail 25 is arranged on the vertical baffle 14, and a slag scraping assembly is arranged on the chain 21. The slag scraping assembly is used to push the intercepted substances on the flat grid plate 12 to the slag guide plate 13 and enter the slag discharging system 3 through the slag guide plate 13; Reserved installation slots for the slag scraping bracket 27 are arranged on the chain 21 at intervals of 0.6 m. Both ends of the slag scraping bracket 27 are fixed on the outside of the chain 21, and the installation distance between adjacent slag scraping brackets 27 is 1.2 m. A movable-connected slag scraping assembly is arranged on the slag scraping bracket 27. The slag scraping assembly includes a scraper 28 and a brush 29 arranged at intervals, and the setting ratio of the scraper 28 to the brush 29 is 8:1. The reciprocating movement of the chain 21 in the guide rail 25 can prevent the chain from derailing and winding of filaments, fibers, etc.

[0059] The slag discharging system 3 includes a high-drainage pressing tank 31, a pressing screw 32, a pressing motor 33 and a slag discharging port 34; A vertically downward slag discharging port 34 is arranged on the high-drainage pressing tank 31. A pressing screw 32 is arranged in the high-drainage pressing tank 31. The pressing screw 32 is driven by the pressing motor 33, and the power of the pressing motor 33 is 1.5 kW·h. Drainage holes are evenly arranged on the drainage side of the high-drainage pressing tank 31, and a brush is arranged on the pressing screw 32.

[0060] The automatic control system 4 automatically adjusts the operating frequency of the driving motor 26 according to the set start time, and then adjusts the slag scraping rate of the slag scraping system 2.

[0061] The operation method of the flat slag scraping type ultra-fine grille for sewage treatment described above includes the following steps: Step 1: Analyze and determine the time periods T1, T2, T3, …, T within 24 hours of a day that exceed the average hourly flow rate and the time periods t1, t2, t3, …, t that are not higher than the average hourly flow rate according to the 24-hour influent volume change curve of the biological pond of the sewage treatment plant in the recent 30 days; n and the time periods t1, t2, t3, …, t that are not higher than the average hourly flow rate; m ; Step 2: Set, through the automatic control system 4, the operating power of the driving motor 26 at a high gear (operating frequency: 30 Hz < n ≤ 50 Hz) during the time periods T1, T2, T3, …, T, and the operating power at a low gear (operating frequency: 10 Hz < f ≤ 30 Hz) during the time periods t1, t2, t3, …, t; m ; f ≤ 30 Hz); Step 3: Start the flat slag scraping type ultra-fine grille for sewage treatment. When in the time periods T1, T2, T3, …, T of a day, the influent volume exceeds the average hourly flow rate, the intercepted suspended substances such as particulate matters and filamentous substances increase, and the slag scraping demand increases. The automatic control system 4 automatically adjusts the driving motor 26 to operate at a high gear (operating frequency: 30 Hz < n ≤ 50 Hz); when entering the time periods t1, t2, t3, …, t, the influent volume drops to a level not higher than the average hourly flow rate, the intercepted suspended substances such as particulate matters and filamentous substances decrease, and the slag scraping demand decreases. The automatic control system 4 automatically switches the driving motor 26 to operate at a low gear (operating frequency: 10 Hz < f ≤ 30 Hz); m ; f ≤ 30 Hz); Step 4: Repeat Step 3 in a cycle.

[0062] When the influent volume exceeds 1.5 times the designed treatment capacity of the flat slag scraping type ultra-fine grille or other failures cause the flat slag scraping type ultra-fine grille to stop operating, the sewage overflows into the water outlet end through the overflow port 15 to ensure the safe operation of the sewage treatment facilities.

[0063] After the flat slag scraping type ultra-fine grille is installed and operated for 2 months, the content of inorganic suspended substances in the biological pond is significantly reduced, and the sludge nitrification rate is increased by 5% - 8% compared with that before installation.

[0064] Finally, it should be noted that the above specific implementation manners are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A flat scraper type ultra-fine grid for sewage treatment, characterized in that: It comprises a grid body (1), a slag scraping system (2), a slag discharge system (3) and an automatic control system (4); The grid body (1) comprises a plane grid plate (12), the plane grid plate (12) being arranged on a supporting keel (17) at an angle of ≤15°, the supporting keel (17) being arranged on a supporting frame (18), vertical baffles (14) having overflow ports (15) being arranged on both sides of the plane grid plate (12), one end of the plane grid plate (12) being connected to a water inlet guide plate (11), and the other end being connected to a slag guide plate (13), the lower part of the slag guide plate (13) being a perforated plate structure, and a water guide plate (16) being arranged on the back side of the slag guide plate (13) for guiding sewage passing through the slag guide plate (13) to a water outlet; The scraping system (2) comprises a driving motor (26), wherein the driving motor (26) drives a chain (21) to reciprocate in a guide rail (25) via a driving shaft (22), a first driven shaft (23), and a second driven shaft (24); the chain (21) is arranged on both sides of the grid body (1); the guide rail (25) is arranged on the vertical baffle (14); a scraping assembly is arranged on the chain (21); the scraping assembly is used to push the retained matter on the plane grid plate (12) toward the slag guide plate (13) and enter the slag discharge system (3) through the slag guide plate (13); The automatic control system (4) automatically adjusts the operating frequency of the drive motor (26) according to the liquid level difference δ between the water inlet and water outlet of the grid body (1) or according to a set start time, thereby adjusting the scraping rate of the scraping system (2).

2. The flat scraping type ultra-fine grid for sewage treatment according to claim 1, characterized in that: The included angle α between the water inlet guide plate (11) and the plane grid plate (12) is 105° to 150°, the water inlet guide plate (11) and the plane grid plate (12) are movably connected, and the plane grid plate (12) is on the top and the water inlet guide plate (11) is on the bottom at the connection point; The plane grid plate (12) is a circular perforated plate structure made of stainless steel, with an opening diameter of 0.2-6 mm, an opening rate of 20%-45%, a thickness of 1-5 mm, a length of 1-6 m, and a width that is 5-30 cm smaller than the width of the installation space.

3. The flat scraping type ultra-fine grid for sewage treatment according to claim 1, characterized in that: The included angle β between the slag guide plate (13) and the plane grid plate (12) is 30° to 75°, and the width and thickness of the slag guide plate (13) are the same as those of the plane grid plate (12); The opening portion of the slag guide plate (13) is located 0.5 to 1.5 m above the connection between the slag guide plate (13) and the plane grid plate (12), the opening aperture is not larger than the aperture of the plane grid plate (12), and the water guide plate (16) is arranged at a height not lower than the top of the opening region of the slag guide plate (13).

4. The flat scraping type ultra-fine grid for sewage treatment according to claim 1, characterized in that: The overflow port (15) is arranged at a middle position above the vertical baffle plate (14), has a length of 1 to 2 m, a height of 5 to 20 cm, and a vertical distance between the bottom of the overflow port (15) and the plane grid plate (12) of 10 to 30 cm.

5. The flat scraper type ultra-fine grid for sewage treatment according to claim 1, characterized in that: On the chain (21), a reserved installation slot for the slag scraping bracket (27) is provided at intervals of 0.5 to 1 m. Both ends of the slag scraping bracket (27) are fixed to the outside of the chain (21). The installation distance between adjacent slag scraping brackets (27) is 0.5 to 1.5 m. A movable slag scraping assembly is provided on the slag scraping bracket (27). The slag scraping assembly includes a scraper (28) and a brush (29) arranged at intervals. The setting ratio of the scraper (28) to the brush (29) is 2:1 to 10:

1.

6. The flat scraping type ultra-fine grid for sewage treatment according to claim 1, characterized in that: The support keel (17) is a steel structure frame in the shape of a Chinese character "tian" or fishbone, fixedly connected to the back of the planar grid plate (12), and in direct contact with the bottom of the installation position. The contact area with the planar grid plate (12) does not exceed 5% of the area of the planar grid plate (12).

7. The flat scraper type ultra-fine grid for sewage treatment according to claim 1, characterized in that: The slag discharging system (3) includes a high-drainage pressing tank (31). A vertically downward slag discharging port (34) is provided on the high-drainage pressing tank (31). A pressing screw (32) is arranged in the high-drainage pressing tank (31). The pressing screw (32) is driven by a pressing motor (33). The power of the pressing motor (33) is 0.75 to 1.5 kW·h. Drainage holes are evenly arranged on the drainage side of the high-drainage pressing tank (31). A brush is arranged on the pressing screw (32).

8. The method for operating the flat scraper type ultra-fine grid for sewage treatment according to claim 1, characterized in that: It includes the following steps: Step S1: Sewage flows through the water inlet diversion plate (11) at the water inlet end to the planar grid plate (12). Impurities including particulate matters and filaments in the sewage are intercepted on the planar grid plate (12) under the filtering action of the planar grid plate (12). The separated sewage enters the water outlet end downward under the action of gravity and inertia. The driving motor (26) drives the chain (21) and the slag scraping assembly arranged thereon to rotate reciprocally through the driving shaft (22), the first driven shaft (23) and the second driven shaft (24) at a low gear, scraping off the particulate matters and filaments intercepted on the planar grid plate (12) and bringing them into the high-drainage pressing tank (31) through the slag guide plate (13). Under the action of the pressing screw (32), the water content is reduced, and it is gradually pressed out of the slag discharging port (34) and then transported out. The sewage carried by the slag scraping assembly is diverted to the water outlet end by the water diversion plate (16) through the orifice structure of the slag guide plate (13). At this time, the liquid level difference δ between the water inlet end and the water outlet end of the grille main body (1) is ≤ 10 cm. Step S2: When the water inflow increases or the concentration of suspended matters including particulate matters and filaments in the influent increases, the liquid level difference between the water inlet end and the water outlet end of the grille main body (1) gradually increases. When the liquid level difference changes within the range of 10 cm < δ ≤ 20 cm and the duration exceeds 10 min, the automatic control system (4) adjusts the operating power of the driving motor (26) to high gear operation. Step S3: When the liquid level difference between the water inlet end and the water outlet end of the grille main body (1) drops to within the range of δ ≤ 10 cm and the duration exceeds 30 min, the automatic control system (4) adjusts the operating power of the driving motor (26) to low gear operation, and the slag scraping rate of the slag scraping system (2) decreases. Step S4, steps S1-S3 are operated alternately in a cycle, wherein the operating frequency of the drive motor (26) in the low gear position is: 10 Hz < f ≤30 Hz, the working frequency at high gear is: 30 Hz< f ≤50 Hz.

9. The method for operating the flat scraper type ultra-fine grid for sewage treatment according to claim 1, characterized in that: The following steps are involved: Step 1: According to the 24-hour water inflow variation curve of the sewage treatment facility in the past 30 days, analyze and determine the time periods T1, T2, T3, ..., T1 that exceed the average flow rate in 24 hours a day. n and the time periods t1, t2, t3, ..., t that are not higher than the average flow rate m ; Step 2: Set the time periods T1, T2, T3, ..., T through the automatic control system (4). n During this period, the operating power of the driving motor (26) is at a high gear, and the time periods are t1, t2, t3, ..., t m During this period, the operating power is at low gear; Step 3: Start the flat scraper type ultra-fine screen for sewage treatment. When it is T1, T2, T3, ..., T n During the time period t1, t2, t3, ..., t m When the water inflow is reduced to a level not higher than the average hourly flow rate, the intercepted suspended matter including particulate matter and filamentous matter is reduced, the scraping demand is reduced, and the automatic control system (4) automatically switches the drive motor (26) to a low gear position for operation; Step 4 and step 3 are cycled or steps 1 to 3 are cycled, wherein the operating frequency of the drive motor (26) at a low gear is: 10 Hz < f ≤30 Hz, the working frequency at high gear is: 30 Hz< f ≤50 Hz.

10. The method for operating the flat scraper type ultra-fine grid for sewage treatment according to claim 8 or 9, characterized in that: When the water intake exceeds 1.5 times the designed processing capacity of the flat-plate scraper type ultra-fine screen or other faults cause the flat-plate scraper type ultra-fine screen to shut down, the sewage overflows through the overflow port (15) into the water outlet.

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