Sewage recycling system for slag treatment

Abstract

The invention discloses a sewage recycling system for slag treatment, and relates to the technical field of sewage recycling. Comprising a sand settling tank used for collecting sewage materials generated by slag treatment and settling the sewage materials to obtain settled sand materials and sewage; feeding the sand settling material into a dewatering screen to obtain fine sand, and circulating the sewage material treated by the dewatering screen back to the sand settling tank; feeding the sewage into a first sewage tank; the first sewage tank is used for storing supernate which is collected by the sand settling tank and is obtained after precipitation, and pumping the supernate into the second sewage tank; the second sewage tank is used for mixing a precipitant into the sewage, carrying out chemical precipitation treatment and feeding the sewage into the press filter; and the press filter is used for realizing mud-water separation on the sewage conveyed by the second sewage tank to obtain recycled clear water. According to the invention, purification treatment of wastewater is realized, so that the wastewater can be discharged up to the standard or recycled, environmental pollution is reduced, the utilization rate of water resources is increased, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage recycling, and in particular to a sewage recycling system for slag treatment. Background Art

[0002] During the wet treatment of slag from municipal solid waste incineration power plants, the washing process generates a large amount of wastewater. This wastewater contains heavy metals such as lead and cadmium. Even at relatively low levels, their potential harm cannot be ignored. It also contains pollutants such as dissolved salts. Direct discharge of this wastewater would cause serious pollution to the soil, water, and other ecological environments, threatening ecological balance and human health.

[0003] Existing slag wastewater treatment methods struggle to effectively remove heavy metals and soluble salts from wastewater, resulting in wastewater that fails to meet discharge standards. This not only wastes water resources but also increases environmental costs. Therefore, it is essential to develop an efficient wastewater recycling system for slag treatment. This system aims to purify wastewater, ensuring it meets discharge standards or is recycled, thereby reducing environmental pollution, improving water resource utilization, and lowering production costs. Summary of the Invention

[0004] In response to the deficiencies in the above-mentioned prior art, the present invention provides a sewage recycling system for slag treatment, which can purify wastewater so that it can be discharged or recycled in compliance with standards, reduce environmental pollution, and at the same time improve water resource utilization and reduce production costs.

[0005] The specific technical solutions are as follows:

[0006] A sewage recycling system for slag treatment, comprising

[0007] The grit tank is used to collect the wastewater material generated by slag treatment and to precipitate the wastewater material to obtain precipitated sand material and wastewater; the precipitated sand material is sent to the dewatering screen to obtain fine sand, and the wastewater material treated by the dewatering screen is recycled back to the grit tank; the wastewater is sent to the first wastewater tank;

[0008] The first sewage tank is used to store the supernatant obtained after sedimentation collected by the grit tank and pump it into the second sewage tank;

[0009] The second sewage tank is used to mix the sewage with a precipitant for chemical precipitation treatment and then send it to the filter press;

[0010] The filter press is used to separate the mud and water from the sewage sent from the second sewage tank to obtain clean water for recycling;

[0011] Among them, the grit tank includes a first separation bin, a second separation bin and a third separation bin arranged in sequence from top to bottom, and a spiral mud-water separation device is provided at the bottom of each separation bin; a water inlet pipe is provided on one side of the upper end of the first separation bin, and the other side of the lower end of the first separation bin is connected with the upper end of the second separation bin through a first connecting pipe, and the lower end of the second separation bin is connected with the upper end of the third separation bin through a second connecting pipe, and the third separation bin is provided with a third connecting pipe as a water outlet; an upright isolation plate is provided between adjacent connecting pipes inside each separation bin, and the upper end of the isolation plate is spaced from the top of the separation bin, and the lower end is spaced from the bottom of the separation bin;

[0012] Each of the separation bins is provided with multiple layers of inclined guide folds from top to bottom, the inclination angle of the guide folds is 60°, and the spacing between adjacent guide folds is 20-30cm; the first connecting pipe and the second connecting pipe are both connecting pipes with gradually expanding diameters along the direction of water flow, and the diameter expansion ratio is 20%; an inclined plate sedimentation assembly is installed on the top of each separation bin, and the inclined plate sedimentation assembly consists of a number of parallel inclined plates with a spacing of 50mm and an inclination angle of 55°, and the top of the inclined plate is close to the inlet of the corresponding connecting pipe; a nano aeration head connected to an external air source is provided on the top of the first separation bin; the spiral mud and water separation device is a coaxial double-layer spiral structure, and the pitch ratio of the outer spiral and the inner spiral is 1.5:1. A liquid level sensor is provided at the bottom of each separation bin, and the liquid level sensor is electrically connected to the drive motor of the spiral mud and water separation device.

[0013] Furthermore, in the above scheme, the outlet of the first connecting tube in the second separation chamber is located at the upper 1 / 3 of the height of its chamber body, and the outlet of the second connecting tube in the third separation chamber is located at the upper 1 / 3 of the height of its chamber body, and the two outlet positions are opposite to each other; the third connecting tube is located on the side of the third separation chamber opposite to the outlet of the second connecting tube, and its outlet height is flush with the outlet of the second connecting tube.

[0014] Furthermore, in the above scheme, the height of the isolation plate is 2 / 3 of the height of the separation bin, the distance between its upper end and the top of the separation bin is 10% of the height of the bin body, and the distance between its lower end and the bottom of the separation bin is 15% of the height of the bin body; the width of the isolation plate in the horizontal direction is the same as the inner diameter of the separation bin.

[0015] Furthermore, in the above solution, the blade surface of the outer spiral is a serrated structure, and the blade surface of the inner spiral is a smooth curved surface. The driving shaft of the double spiral realizes the outer and inner layer speed difference control through a transmission.

[0016] Furthermore, in the above scheme, the second sewage tank has chambers arranged in sequence from top to bottom, and a ring-shaped water flow channel is provided on the bottom surface of the chamber, with the ends of the water flow channel connected end to end; the precipitant release device is provided at the connecting channel between adjacent chambers.

[0017] Furthermore, in the above solution, the microbubble generating pore size of the nano aeration head is 20-50 microns, and the aeration heads are evenly distributed 10 cm below the liquid surface at the top of the first separation chamber.

[0018] The above scheme further provides a filter drum above the sand settling tank, and the polyester filter has a filtration size of 200 meshes; the filter drum is a conical cylinder structure, and the sewage material is introduced from the cone cylinder, the larger end of the cone cylinder corresponds to the sedimentation tank, and the bottom corresponds to the collection tank.

[0019] Furthermore, in the above solution, the isolation plate is evenly distributed with through holes, the through holes have a diameter of 1-5 mm, and the through holes are arranged in a staggered manner.

[0020] Furthermore, the above scheme comprises a spiral mud-water separation device including a coaxially arranged spiral rod and a drive motor. The spiral rod is located in a conical tube body, the larger end of the tube body is connected to the bottom of the separation bin, the smaller end extends upward at an angle and is provided with a slag discharge port, and the taper of the tube body is adapted to the pitch of the spiral rod.

[0021] Furthermore, in the above solution, the inlet heights of the first connecting pipe, the second connecting pipe and the third connecting pipe are all lower than the top of the isolation plate, and the distance between the inlet position and the isolation plate is 20% of the height of the isolation plate.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention implements graded sedimentation and mud-water separation of slag wastewater by providing a multi-stage separation chamber, multiple sedimentation components, and a spiral mud-water separation device, significantly improving impurity removal efficiency and avoiding the problem of insufficient single-time sedimentation. The system's multiple links operate in synergy to achieve full mixing of the precipitant and wastewater, and effective separation of mud and water, allowing the treated wastewater to meet discharge standards or be recycled, reducing water resource waste and environmental pollution. Furthermore, designs such as the liquid level sensor-linked spiral device and a reasonable connecting pipe structure not only enhance the system's automation level, but also optimize the sewage flow path, reduce the risk of equipment blockage, and lower operating and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the sewage circulation system for slag treatment of the present invention;

[0025] Figure 2 It is a schematic diagram of the grit tank structure.

[0026] In the accompanying drawings, 1-sand settling tank, 2-first sewage tank, 3-second sewage tank, 4-filter press, 5-floating cage, 6-dewatering screen, 11-first separation chamber, 12-second separation chamber, 13-third separation chamber, 14-water inlet pipe, 15-first connecting pipe, 16-isolation plate 17-second connecting pipe, 18-third connecting pipe, 19-spiral mud and water separation device. DETAILED DESCRIPTION

[0027] The following is a further detailed description of the embodiments of the invention in conjunction with the accompanying drawings to make the objectives, technical solutions and technical effects of the invention more clearly presented.

[0028] like Figure 1-2 As shown, the present invention discloses a wastewater recycling system for slag treatment, comprising a grit tank 1, a first wastewater tank 2, a second wastewater tank 3, and a filter press 4. The grit tank 1 is used to collect wastewater generated by slag treatment and precipitate the wastewater to obtain precipitated sand and wastewater. The precipitated sand is fed to a dewatering screen 6 to obtain fine sand. The wastewater treated by the dewatering screen 6 is then recycled back to the grit tank 1. The wastewater is then fed to the first wastewater tank 2. The first wastewater tank 2 stores the supernatant obtained after precipitation in the grit tank 1 and pumps it into the second wastewater tank 3. The second wastewater tank 3 is used to mix the wastewater with a precipitant for chemical precipitation treatment, and then feed it into the filter press 4. The filter press 4 separates the mud and water from the wastewater fed from the second wastewater tank 3 to obtain clean water for recycling.

[0029] Specifically, grit tank 1 collects wastewater generated by slag treatment and, through sedimentation, produces precipitated sand and wastewater. The precipitated sand is fed to a dewatering screen 6, and the treated wastewater is circulated back to grit tank 1. The wastewater is then fed to a first wastewater tank 2. First wastewater tank 2 stores the supernatant obtained after sedimentation in grit tank 1 and pumps it into a second wastewater tank 3. A precipitant is added to the wastewater in second wastewater tank 3 for chemical precipitation, and the wastewater is then fed to a filter press 4. Filter press 4 separates the mud and water in the wastewater from second wastewater tank 3, producing clean water for recycling.

[0030] Here, the grit chamber 1 includes a first separation chamber 11, a second separation chamber 12, and a third separation chamber 13, which are arranged in sequence from top to bottom. A spiral mud-water separation device 19 is provided at the bottom of each separation chamber. A water inlet pipe 14 is provided on one side of the upper end of the first separation chamber 11. The other side of the lower end of the first separation chamber 11 is connected to the upper end of the second separation chamber 12 via a first connecting pipe 15. The lower end of the second separation chamber 12 is connected to the upper end of the third separation chamber 13 via a second connecting pipe 17. The third separation chamber 13 is provided with a third connecting pipe 18 as a water outlet. Inside each separation chamber, an upright isolation plate 16 is provided between adjacent connecting pipes. The upper end of the isolation plate 16 is spaced from the top of the separation chamber, and the lower end is spaced from the bottom of the separation chamber. Each separation chamber is provided with multiple layers of inclined guide folds from top to bottom. The inclination angle of the guide folds is 60°, and the spacing between adjacent guide folds is 20-30 cm. Both the first connecting pipe 15 and the second connecting pipe 17 have a diameter that gradually expands along the direction of water flow, with the diameter expanding by 20%. Each separation chamber is topped with an inclined plate settling assembly, consisting of several parallel inclined plates spaced 50 mm apart and tilted at a 55° angle, with the tops of the inclined plates positioned near the inlets of the corresponding connecting pipes. A nano-aeration head connected to an external air source is located at the top of the first separation chamber 11. The spiral mud-water separator 19 is a coaxial double-layer helical structure with a pitch ratio of 1.5:1 between the outer and inner helices. A liquid level sensor is located at the bottom of each separation chamber, electrically connected to the drive motor of the spiral mud-water separator 19.

[0031] The grit chamber 1 is sequentially arranged from top to bottom with a first separation chamber 11, a second separation chamber 12, and a third separation chamber 13, which are connected in sequence via connecting pipes to achieve multi-stage sedimentation of the wastewater. This multi-stage sedimentation allows impurities in the wastewater to settle more thoroughly, resolving the problem of a single settling cycle in which impurities are difficult to completely remove. A spiral mud-water separator 19 is installed at the bottom of each separation chamber. This coaxial double-helical structure features a pitch ratio of 1.5:1 between the outer and inner helices, and is electrically connected to a liquid level sensor. The liquid level sensor controls the drive motor of the spiral mud-water separator 19 based on the liquid level within the separation chamber. When the liquid level reaches a certain level, the spiral mechanism is activated to transport the precipitated sand material. This structure allows for more efficient mud-water separation, transporting the precipitated sand material to the dewatering screen 6, eliminating the problem of precipitated sand material accumulating at the bottom of the separation chamber, impacting the sedimentation effect. Each separation chamber is equipped with multiple layers of inclined guide flaps from top to bottom, with an inclination angle of 60° and a spacing of 20-30 cm between adjacent guide flaps. The diversion flaps alter the flow path of the wastewater, extending its residence time within the separation chamber and enhancing sedimentation efficiency, thus resolving the issue of insufficient sedimentation caused by rapid wastewater flow through the separation chamber. Both the first connecting pipe 15 and the second connecting pipe 17 feature a 20% diameter expansion along the direction of flow. This gradual expansion slows the flow of wastewater, facilitating the sedimentation of impurities and resolving the issue of excessive wastewater flow affecting sedimentation efficiency. Each separation chamber is topped with an inclined plate sedimentation assembly, consisting of several parallel inclined plates spaced 50 mm apart and tilted at a 55° angle. The tops of the inclined plates are positioned near the inlet of the corresponding connecting pipe. This increases the sedimentation area, improves sedimentation efficiency, and further removes impurities from the wastewater, resolving the issue of insufficient sedimentation efficiency resulting from insufficient sedimentation area. A nano-aeration head connected to an external air source is installed at the top of the first separation chamber 11. The microbubble generation apertures have a diameter of 20-50 microns and are evenly distributed 10 cm below the liquid level at the top of the first separation chamber 11. The microbubbles generated by the nano-aeration head agglomerate tiny particles in the wastewater, facilitating sedimentation and resolving the issue of small particles having difficulty settling.

[0032] Here, the outlet of the first connecting pipe 15 in the second separation chamber 12 is located at the upper 1 / 3 of its chamber height, and the outlet of the second connecting pipe 17 in the third separation chamber 13 is located at the upper 1 / 3 of its chamber height, with the two outlets facing each other. The third connecting pipe 18 is located on the side of the third separation chamber 13 opposite the outlet of the second connecting pipe 17, and its outlet height is flush with the outlet of the second connecting pipe 17. This arrangement can form a more reasonable flow path for sewage in each separation chamber, further improve the sedimentation effect, and solve the problem of uneven sedimentation caused by irrational sewage flow in the separation chamber.

[0033] Furthermore, the height of the isolation plate 16 is two-thirds of the height of the separation chamber, the distance between its upper end and the top of the separation chamber is 10% of the chamber height, and the distance between its lower end and the bottom of the separation chamber is 15% of the chamber height. The horizontal width of the isolation plate 16 is the same as the inner diameter of the separation chamber. This dimensioning better guides the flow of sewage within the separation chamber, forming a specific flow path between adjacent connecting pipes, enhancing sedimentation efficiency, and solving the problem of turbulent sewage flow affecting sedimentation.

[0034] Furthermore, the outer spiral blades have a serrated surface, while the inner spiral blades have a smooth, curved surface. The drive shaft of the double spiral is controlled by a transmission to achieve differential speed control between the outer and inner spirals. The serrated blades better capture sedimentary sand, while the smooth curved blades reduce crushing and impacting the sand. This differential speed control allows for more efficient mud-water separation, resolving the issue of spiral devices' poor sand handling performance.

[0035] Here, the second sewage tank 3 is arranged with chambers arranged from top to bottom. The bottom of each chamber is provided with a circular water flow channel, with the ends of the water flow channel connected end to end. The precipitant release device is located in the channel connecting adjacent chambers. This arrangement allows the sewage to flow fully within the second sewage tank 3 and mix thoroughly with the precipitant, improving the chemical precipitation effect and solving the problem of uneven mixing of the precipitant and sewage. The nano aeration heads have a microbubble generation aperture of 20-50 microns and are evenly distributed 10 cm below the liquid level at the top of the first separation chamber 11.

[0036] Furthermore, a filter drum is installed above the grit chamber 1. The polyester filter screen has a 200-mesh filter size. The filter drum is a conical cylinder, through which the sewage is introduced. The larger end of the cylinder corresponds to the sedimentation tank, while the bottom corresponds to the collection tank. The filter drum can pre-filter large impurities in the sewage, reducing the burden on subsequent treatment steps and preventing large impurities from damaging subsequent treatment equipment or affecting treatment effectiveness.

[0037] Furthermore, the isolation plates 16 are uniformly distributed with through-holes, each with a diameter of 1-5 mm, and are arranged in a staggered pattern. These holes allow sewage to flow more evenly between adjacent connecting pipes while also preventing large impurities from passing directly through, further improving the sedimentation effect and resolving the issues of uneven sewage flow and large impurities affecting sedimentation.

[0038] Furthermore, the spiral mud-water separator 19 comprises a coaxially arranged spiral rod and a drive motor. The spiral rod is located within a tapered tube. The larger end of the tube is connected to the bottom of the separation chamber, while the smaller end extends upward at an angle and is provided with a slag discharge port. The taper of the tube is adapted to the spiral rod's pitch. This structure can more efficiently transport the precipitated sand material while preventing sand backflow, thus solving the problem of poor sand transport and backflow.

[0039] like Figure 2 As shown, the dotted arrows represent the direction of water flow, and the solid arrows represent the direction of sediment discharge.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the patent application of the present invention. Any equivalent changes, equivalent replacements or modifications performed within the technical spirit and principles suggested by the present invention should be included in the scope of patent protection covered by the present invention.

Claims

1. A wastewater recycling system for slag treatment, characterized by: include The grit tank is used to collect the wastewater material generated by slag treatment and to precipitate the wastewater material to obtain precipitated sand material and wastewater; the precipitated sand material is sent to the dewatering screen to obtain fine sand, and the wastewater material treated by the dewatering screen is recycled back to the grit tank; the wastewater is sent to the first wastewater tank; The first sewage tank is used to store the supernatant obtained after sedimentation collected by the grit tank and pump it into the second sewage tank; The second sewage tank is used to mix the sewage with a precipitant for chemical precipitation treatment and then send it to the filter press; The filter press is used to separate the mud and water from the sewage sent from the second sewage tank to obtain clean water for recycling; Among them, the grit tank includes a first separation bin, a second separation bin and a third separation bin arranged in sequence from top to bottom, and a spiral mud-water separation device is provided at the bottom of each separation bin; a water inlet pipe is provided on one side of the upper end of the first separation bin, and the other side of the lower end of the first separation bin is connected with the upper end of the second separation bin through a first connecting pipe, and the lower end of the second separation bin is connected with the upper end of the third separation bin through a second connecting pipe, and the third separation bin is provided with a third connecting pipe as a water outlet; an upright isolation plate is provided between adjacent connecting pipes inside each separation bin, and the upper end of the isolation plate is spaced from the top of the separation bin, and the lower end is spaced from the bottom of the separation bin; Each of the separation bins is provided with multiple layers of inclined guide folds from top to bottom, the inclination angle of the guide folds is 60°, and the spacing between adjacent guide folds is 20-30cm; the first connecting pipe and the second connecting pipe are both connecting pipes with gradually expanding diameters along the direction of water flow, and the diameter expansion ratio is 20%; an inclined plate sedimentation assembly is installed on the top of each separation bin, and the inclined plate sedimentation assembly consists of a number of parallel inclined plates with a spacing of 50mm and an inclination angle of 55°, and the top of the inclined plate is close to the inlet of the corresponding connecting pipe; a nano aeration head connected to an external air source is provided on the top of the first separation bin; the spiral mud and water separation device is a coaxial double-layer spiral structure, and the pitch ratio of the outer spiral and the inner spiral is 1.5:

1. A liquid level sensor is provided at the bottom of each separation bin, and the liquid level sensor is electrically connected to the drive motor of the spiral mud and water separation device.

2. The sewage recycling system for slag treatment according to claim 1, characterized in that: The outlet of the first connecting tube in the second separation chamber is located at the upper 1 / 3 of the height of its chamber body, and the outlet of the second connecting tube in the third separation chamber is located at the upper 1 / 3 of the height of its chamber body, and the two outlets are opposite to each other; the third connecting tube is located on the side of the third separation chamber opposite to the outlet of the second connecting tube, and its outlet height is flush with the outlet of the second connecting tube.

3. The sewage recycling system for slag treatment according to claim 1, characterized in that: The height of the isolation plate is 2 / 3 of the height of the separation bin, the distance between its upper end and the top of the separation bin is 10% of the bin height, and the distance between its lower end and the bottom of the separation bin is 15% of the bin height; the width of the isolation plate in the horizontal direction is the same as the inner diameter of the separation bin.

4. The sewage recycling system for slag treatment according to claim 1, characterized in that: The blade surface of the outer spiral is a sawtooth structure, and the blade surface of the inner spiral is a smooth curved surface. The driving shaft of the double spiral realizes the difference control of the outer and inner layer speeds through a transmission.

5. The sewage recycling system for slag treatment according to claim 1, characterized in that: The second sewage tank has chambers arranged in sequence from top to bottom, and a ring-shaped water flow channel is provided on the bottom of the chamber, with the ends of the water flow channel connected end to end; the precipitant release device is arranged at the connecting channel between adjacent chambers.

6. The sewage recycling system for slag treatment according to claim 1, characterized in that: The microbubble generating pore diameter of the nano aeration head is 20-50 microns, and the aeration heads are evenly distributed 10 cm below the liquid surface at the top of the first separation chamber.

7. The sewage recycling system for slag treatment according to claim 2, characterized in that: A filter drum is provided above the sand settling tank, and the polyester filter has a filtration size of 200 meshes; the filter drum is a conical cylinder structure, and the sewage material is introduced into the cone cylinder. The larger end of the cone cylinder corresponds to the sedimentation tank, and the bottom corresponds to the collection tank.

8. The sewage recycling system for slag treatment according to claim 1, characterized in that: The isolation plate is evenly distributed with through holes, the diameter of the through holes is 1-5 mm, and the through holes are arranged in a staggered manner.

9. The sewage recycling system for slag treatment according to claim 7, characterized in that: The spiral mud and water separation device includes a coaxially arranged spiral rod and a drive motor. The spiral rod is located in a conical tube body. The larger end of the tube body is connected to the bottom of the separation bin, and the smaller end extends upward at an angle and is provided with a slag discharge port. The taper of the tube body is adapted to the pitch of the spiral rod.

10. The sewage recycling system for slag treatment according to claim 8, characterized in that: The inlet heights of the first connecting pipe, the second connecting pipe and the third connecting pipe are all lower than the top of the isolation plate, and the distance between the inlet position and the isolation plate is 20% of the height of the isolation plate.

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