Sludge gravity concentration system

Abstract

The utility model discloses a sludge gravity concentration system and belongs to the technical field of sludge concentration treatment. The sludge gravity concentration system comprises a mixing device, a gravity concentration device and a separation device, the mixing device comprises a feed port II and a discharge port; the gravity concentration device comprises a feed port, a discharge port and a water outlet, the separation device comprises a feed port, a discharge port I and a discharge port II, the mixing device is used for mixing residual sludge and filler, and the discharge port of the mixing device is connected with the feed port of the gravity concentration device; a discharge port of the gravity concentration device is connected with a feed port of the separation device, and the gravity concentration device is provided with a sludge concentrator; a first discharging port of the separating device is connected with a second feeding port of the mixing device. The gravity concentration device is mainly used for improving the concentration effect of the gravity concentration device by loading the filler.

Description

Technical Field

[0001] The utility model relates to the technical field of sludge thickening treatment, and more specifically, to a sludge gravity thickening system. Background Technique

[0002] At present, the biochemical treatment system of sewage treatment plants needs to regularly discharge excess sludge. Before sludge dewatering, a sludge gravity thickening tank is often set up for the excess sludge of the biochemical system, and the moisture content of the excess sludge of the biochemical system is concentrated from 99.2% - 99.6% to 97% - 98%. The two relatively key technical indicators in the design of the gravity thickening tank are the solid flux and the hydraulic load.

[0003] Since the excess sludge discharged from the biochemical system is relatively difficult to thicken, the designed solid flux is often relatively low to ensure the thickening effect. According to the "Design Standard for Outdoor Wastewater Disposal" (2021 Edition), the sludge solid flux should preferably be 30 - 60 kg / (m 2 ·d), the sludge thickening time should not be less than 12 h, and the effective water depth should preferably be 4 m. If designed according to these requirements in engineering, it will cause the volume of the thickening tank to be too large and the sludge thickening time to be too long, resulting in the phosphorus absorbed in the excess sludge being released in the anaerobic environment and returning to the biochemical system through the supernatant. When the temperature is relatively high, it is easy to have anaerobic gas release and cause the sludge to float. In addition, for the in-situ upgrading and expansion of existing sewage treatment plants, it is easy to cause an increase in the total excess sludge volume of the whole plant, thereby increasing the solid flux and hydraulic load of the existing gravity thickening tank and affecting its thickening effect. The main method in the prior art to improve the thickening effect of the gravity thickening tank is the chemical method, by adding flocculants to the gravity thickening tank to flocculate fine particles and other substances into larger flocs. However, since the formed flocs have a relatively large volume, the resistance they encounter when sinking under the action of gravity is also greater, affecting the thickening efficiency.

[0004] Therefore, there is an urgent need for a sludge gravity thickening system that can solve the above problems. Summary of the Utility Model

[0005] 1. Technical Problems to be Solved by the Utility Model

[0006] The purpose of the utility model is to overcome the deficiency of poor thickening effect of the gravity thickening device in the prior art, and provide a sludge gravity thickening system.

[0007] 2. Technical Solution

[0008] To achieve the above purpose, the technical solution provided by the utility model is as follows:

[0009] A sludge gravity thickening system of the utility model includes a mixing device, a gravity thickening device, and a separation device;

[0010] The mixing device includes a second feed inlet and a discharge outlet;

[0011] The gravity thickening device includes a feed inlet, a discharge outlet, and a water outlet.

[0012] The separation device includes a feed inlet, a first discharge outlet, and a second discharge outlet.

[0013] The mixing device is used to mix the excess sludge and the filler. The discharge outlet of the mixing device is connected to the feed inlet of the gravity thickening device.

[0014] The discharge outlet of the gravity thickening device is connected to the feed inlet of the separation device. The gravity thickening device is provided with a sludge thickener.

[0015] The first discharge outlet of the separation device is connected to the second feed inlet of the mixing device.

[0016] It should be noted that the excess sludge and the filler are fully mixed in the mixing device. Then, the excess sludge mixed with the filler enters the gravity thickening device. Under the action of gravity and the sludge thickener, the sludge descends and the liquid ascends, realizing concentration layering to obtain supernatant and sludge layer. The supernatant can be discharged through the water outlet, and the sludge in the sludge layer enters the separation device for separating the filler from the excess sludge. The separated filler can be re-injected into the mixing device for recycling, and the separated excess sludge can enter the sludge dewatering section.

[0017] Among them, the full mixing of the excess sludge and the filler in the mixing device not only enables the filler to enter the flocs formed by the zoogloea in the excess sludge, increasing the weight of the flocs to accelerate the sedimentation of the sludge, improving the solid flux of the gravity thickening device, reducing the hydraulic retention time of the excess sludge, and enhancing the treatment effect and efficiency of the gravity thickening device, but also ensures that the filler is relatively evenly distributed in the excess sludge after mixing, making the descending speed of the sludge everywhere in the gravity thickening device basically the same during gravity thickening.

[0018] Furthermore, the water outlet of the gravity thickening device is connected to the plant sewage pipe network.

[0019] Furthermore, the mixing device includes a stirring component.

[0020] Furthermore, the stirring component can be an axial flow agitator. The number of paddle layers on the axial flow agitator can be determined according to the diameter-depth ratio of the mixing device, usually 1 - 3 layers.

[0021] The diameter-depth ratio is the equivalent diameter of the mixing device / effective depth, where the effective depth refers to the depth of the excess sludge after mixing in the mixing device; when the mixing device is a circular tank, the equivalent diameter is equal to its diameter.

[0022] Furthermore, the particle size of the filler is 50 - 250 microns.

[0023] It should be noted that the particle size of the filler is in the range of 50 to 250 microns and can enter the flocs formed by the zoogloea in the excess sludge.

[0024] Preferably, the particle size of the filler is 100 to 150 microns

[0025] Furthermore, the true density of the filler is 1300 to 3500 kg / m 3 。

[0026] It should be noted that since the true density of the filler is 1300 to 3500 kg / m 3 , which is greater than the density of the activated sludge, there is a density difference between the two, which is beneficial for the separation device to separate the filler from the excess sludge.

[0027] Furthermore, the filler is one of sand and finely ground ore.

[0028] Preferably, the filler is sand.

[0029] Furthermore, the uniformity coefficient (d 60 / d 10 ) ≤ 1.7.

[0030] A more uniform particle size distribution of the filler is beneficial for maintaining a consistent downward velocity of the sludge everywhere during concentration, and is also beneficial for separation and improving the recovery rate. For example, it is beneficial for separating and recovering the filler in a hydrocyclone.

[0031] Preferably, the filler is sand screened from sea sand or river sand that meets the particle size requirements to reduce the treatment cost.

[0032] Furthermore, it further includes a storage device and a second conveying device.

[0033] The storage device includes a feed inlet and a discharge outlet;

[0034] The second discharge outlet of the separation device is connected to the feed inlet of the storage device.

[0035] Furthermore, the discharge outlet of the separation device is connected to a second conveying device.

[0036] Furthermore, the second conveying device can be connected to a sludge dewatering machine.

[0037] Furthermore, a first conveying device is provided between the discharge outlet of the gravity thickening device and the feed inlet of the separation device.

[0038] Furthermore, the separation device includes a plurality of hydrocyclones;

[0039] The hydrocyclone includes a mud inlet, an overflow outlet, and a grit outlet.

[0040] The mud inlets, overflow outlets, and grit outlets of several hydrocyclones are respectively connected through connecting components.

[0041] Furthermore, it also includes a filler dosing device and a surplus sludge dosing device.

[0042] The surplus sludge dosing device includes a discharge port.

[0043] The filler dosing device includes a discharge port, and the mixing device also includes a first feed port and a third feed port.

[0044] The discharge port of the surplus sludge dosing device is connected to the first feed port of the mixing device, and the discharge port of the filler dosing device is connected to the third feed port of the mixing device.

[0045] Accordingly, the operating principle of the sludge gravity thickening system provided by the present utility model is as follows:

[0046] Mix the surplus sludge with a filler having a particle size of 50 - 250 microns in the mixing device, and fully stir and mix them so that the filler enters the flocs formed by the zoogloea in the surplus sludge, increasing the density and weight of the flocs, which is beneficial to the accelerated sedimentation of the sludge and improves the thickening efficiency and effect of the surplus sludge.

[0047] The mixed surplus sludge is sent to the gravity thickening device. Under the action of gravity, the surplus sludge descends and the liquid rises, achieving thickening and stratification to obtain supernatant and sludge layer.

[0048] The surplus sludge in the sludge layer is transported to the separation device for separation. The separated filler is transported to the mixing device for recycling, and the surplus sludge is transported to the sludge dewatering section; the supernatant is discharged through the water outlet of the gravity thickening device.

[0049] 3. Beneficial effects

[0050] Adopting the technical solution provided by the present utility model, compared with the prior art, it has the following beneficial effects:

[0051] The gravity thickening system provided by the present utility model includes a mixing device, a gravity thickening device, and a separation device; the mixing device includes a second feed port and a discharge port; the gravity thickening device includes a feed port, a discharge port, and a water outlet, and the separation device includes a feed port, a first discharge port, and a second discharge port. The mixing device is used to mix the surplus sludge and the filler, and the discharge port of the mixing device is connected to the feed port of the gravity thickening device; the discharge port of the gravity thickening device is connected to the feed port of the separation device, and the gravity thickening device is provided with a sludge thickener; the first discharge port of the separation device is connected to the second feed port of the mixing device.

[0052] Among them, the excess sludge and the packing are fully mixed in the mixing device, which not only enables the packing to enter the flocs formed by the zoogloea in the excess sludge, increasing the density and weight of the flocs to accelerate the sludge settlement, improving the solid flux of the gravity thickening device, reducing the hydraulic retention time of the excess sludge, and enhancing the treatment effect and efficiency of the gravity thickening device; but also ensures that the packing is relatively evenly distributed in the excess sludge after mixing, making the downward velocities of the sludge at various parts in the gravity thickening device basically the same during gravity thickening; the packing can also be separated by the separation device and recycled, reducing the treatment cost. Brief Description of the Drawings

[0053] Figure 1 This is a sludge gravity thickening system in Embodiment 1 of the present invention;

[0054] Figure 2 This is a hydrocyclone in Embodiment 1 of the present invention;

[0055] Figure 3 This is a hydrocyclone group in Embodiment 1 of the present invention.

[0056] Explanation of the reference numerals in the schematic diagram:

[0057] 100, gravity thickening device; 110, sludge thickener;

[0058] 200, first conveying device;

[0059] 300, mixing device; 310, stirring component;

[0060] 400, separation device; 410, overflow port; 420, sludge inlet; 430, grit outlet; 440, overflow conduit; 450, column body; 460, large cone; 470, small cone; 480, connecting component.

[0061] 500, storage device;

[0062] 600, second conveying device;

[0063] 700, excess sludge dosing device;

[0064] 800, packing dosing device. Detailed Embodiment

[0065] To further understand the content of the present utility model, the present utility model will be described in detail in conjunction with the drawings and embodiments.

[0066] The structures, proportions, sizes, etc. shown in the accompanying drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in this utility model. At the same time, terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of clear narration and are not used to limit the scope of implementation. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0067] Example 1

[0068] Combined with Figure 1 , the sludge gravity thickening system of this embodiment includes a mixing device 300, a gravity thickening device 100, and a separation device 400; the mixing device 300 includes a second feed port and a discharge port; the gravity thickening device 100 includes a feed port, a discharge port, and a water outlet, and the separation device 400 includes a feed port, a first discharge port, and a second discharge port. The mixing device 300 is used to mix the excess sludge and the filler. The discharge port of the mixing device 300 is connected to the feed port of the gravity thickening device 100; the discharge port of the gravity thickening device 100 is connected to the feed port of the separation device 400. The gravity thickening device 100 is provided with a sludge thickener 110; the first discharge port of the separation device 400 is connected to the second feed port of the mixing device 300.

[0069] Specifically, the excess sludge and the filler are fully mixed in the mixing device 300, and then the excess sludge mixed with the filler enters the gravity thickening device 100. Under the action of gravity and the sludge thickener 110, the sludge descends and the liquid rises to achieve concentration stratification, obtaining supernatant liquid and a sludge layer. The supernatant liquid can be discharged through the water outlet, and the sludge in the sludge layer enters the separation device 400 to separate the filler from the excess sludge. The separated filler can be added back to the mixing device 300 for recycling, and the separated excess sludge can enter the sludge dewatering section.

[0070] It should be noted that the excess sludge and the filler are fully mixed in the mixing device 300. On the one hand, the filler can enter the flocs formed by the bacterial flocs in the excess sludge, increase the density and weight of the flocs, and help accelerate the sinking of the sludge, improve the solid flux of the gravity concentrator 100, reduce the hydraulic retention time of the excess sludge, and help to concentrate the water content of the excess sludge to 96% to 98% more quickly. The treatment effect and efficiency of the gravity concentrator 100 are improved; this helps to solve the problems of low solid flux of gravity concentrators 100 such as the sludge gravity concentrator tank of a newly built sewage treatment plant, large tank capacity and easy sludge floating when built according to standards, and the problem that the excess sludge amount increased due to the in-situ upgrading and expansion of the existing sewage treatment plant affects the concentration effect of the existing concentrator tank;

[0071] On the other hand, it ensures that the filler is evenly distributed in the remaining sludge after mixing, so that the descending speed of the sludge at various locations in the gravity concentrating device 100 is basically the same during gravity concentration.

[0072] In addition, the sludge thickener 110 is used to disperse the sludge in the sludge layer through mechanical stirring, so that the water in the sludge layer is easier to rise, and the sludge in the sludge layer is easier to fall to the bottom of the gravity thickening device 100, so that the sludge can be transported to the separation device 400. Figure 1 The sludge thickener 110 can concentrate the sludge in the sludge layer to the bottom of the gravity thickener 100, that is, the conical sludge hopper, for easy transportation. Further, the sludge thickener 110 has a plurality of bars and is driven by a power mechanism, which can be a conventional motor in the industry.

[0073] As a specific implementation manner, the excess sludge may be activated sludge discharged from a biochemical treatment system.

[0074] Furthermore, the particle size of the filler is 50 to 250 microns. It should be noted that the filler particle size is within the range of 50 to 250 microns, which can enter the flocs formed by the bacterial flocs in the residual sludge; if the filler particle size is too large, it is not conducive to entering the flocs and driving the sludge to sink; if the filler particle size is too small, its mass is too small and is not conducive to driving the sludge to sink. On the other hand, the true density of the filler is 1300 to 3500 kg / m 3 Since the actual density of the filler itself is 1300~3500kg / m 3 , has a greater density than the remaining sludge, and the density difference between the two is conducive to the separation device 400 to separate the filler from the remaining sludge.

[0075] Furthermore, the uniformity coefficient of the packing (d 60 / d 10) ≤ 1.7. A more uniform filler particle size distribution is beneficial for maintaining a consistent downward velocity of the sludge at various locations during concentration, and is also beneficial for separation and improving the recovery rate.

[0076] Specifically, the filler is one of sand and finely ground ore. As an implementation manner, the sand is selected from sea sand or river sand that meets the particle size requirements. As an alternative implementation manner, the filler can be quartz sand.

[0077] In addition, the water outlet of the gravity thickening device 100 is connected to the factory sewage pipe network. After the thickening is completed, the supernatant in the gravity thickening device 100 is discharged into the factory sewage pipe network through the water outlet.

[0078] As an alternative implementation manner, a stirring component 310 is provided in the mixing device 300 for stirring the excess sludge and the filler to make them fully mixed. As a specific implementation manner, the mixing device 300 is a mixing tank or a steel structure mixing tank, and an axial flow stirrer is provided in the mixing tank as the stirring component 310. The number of layers of the blades on the axial flow stirrer can be determined according to the diameter-depth ratio of the mixing tank, usually 1 to 3 layers. The diameter-depth ratio is the equivalent diameter of the mixing device 300 / effective depth, where the effective depth refers to the depth of the mixed excess sludge in the mixing device 300; when the mixing device 300 is a circular tank, the equivalent diameter is equal to its diameter. The gravity thickening device 100 is a gravity thickening tank, and a sludge thickener 110 with multiple grid bars is provided at the central position of the gravity thickening tank.

[0079] Combined with Figure 2 and Figure 3, As an alternative embodiment, the separation device 400 can be a hydrocyclone, which includes a mud inlet 420, an overflow outlet 410, and a grit outlet 430; it can also be a hydrocyclone group formed by several hydrocyclones. In this case, the mud inlets 420, overflow outlets 410, and grit outlets 430 of the several hydrocyclones are respectively connected through a connecting member 480. The connecting member 480 can be a connecting pipe or a liquid coupling box. Among them, the connecting pipe connected to the grit outlet 430 can be inclined to facilitate the flow of the separated packing. When the separation device 400 is a hydrocyclone group, multiple hydrocyclones can be fixed by fixing devices such as fixing brackets, and the number of operating hydrocyclones can be determined according to the processing capacity. Specifically, valves can be provided on the connecting member 480 to control the operation of the hydrocyclone through the opening and closing of the valves. Specifically, the mixture of excess sludge and packing enters the cylinder 450 of the hydrocyclone from the tangential mud inlet 420 of the hydrocyclone under pressure drive, rotates at high speed inside the hydrocyclone, and after passing through the large cone 460, due to the reduction of the flow channel cross-section, the liquid flow speed increases and forms a spiral flow state. When the material enters the small cone 470, due to the further reduction of the flow channel cross-section, the swirl speed continues to increase, and a stable centrifugal force field is formed inside the separation core. The excess sludge with a lower specific gravity coalesces in the central area of the cone tube, enters the inner swirl flow, and is discharged from the overflow outlet 410 through the overflow conduit 440; the packing with a higher specific gravity accumulates near the pipe wall, enters the outer swirl flow, and is discharged from the grit outlet 430, realizing the separation of excess sludge and packing.

[0080] A first conveying device 200 is provided between the discharge port of the gravity thickening device 100 and the feed port of the separation device 400, which is used to extract and convey the mixture of excess sludge and packing in the thickened sludge layer to the separation device 400 for separation. Different numbers of first conveying devices 200 can be set according to the actual processing capacity. For example, when the separation device 400 is a hydrocyclone, when conveying the sludge to the hydrocyclone, the required flow rate and pressure should also be met. As a specific embodiment, the first conveying device 200 is a slurry pump. The inside of the slurry pump is lined with rubber, which is more suitable for application scenarios with sand and wear resistance.

[0081] As an alternative embodiment, the system may further be provided with a filler dosing device 800 and a surplus sludge dosing device 700. The filler dosing device 800 is used to dose fillers into the mixing device 300, and the surplus sludge dosing device 700 is used to dose surplus sludge into the mixing device 300. The surplus sludge dosing device 700 includes a discharge port, and the filler dosing device 800 includes a discharge port; the mixing device 300 further includes a first feed port and a third feed port. The discharge port of the surplus sludge dosing device 700 is connected to the first feed port of the mixing device 300, and the discharge port of the filler dosing device 800 is connected to the third feed port of the mixing device 300, so as to supplement and add surplus sludge and fillers into the mixing device 300 respectively. As an alternative embodiment, both the first feed port and the third feed port of the mixing device 300 are provided at the upper part, and the filler dosing device 800 and the surplus sludge dosing device 700 can use conveying mechanisms such as vertical screw conveyors to dose fillers and surplus sludge into the mixing device 300.

[0082] As another alternative embodiment, the dosing of surplus sludge and fillers can be carried out manually.

[0083] Furthermore, the system further includes a storage device 500. The storage device 500 includes a feed port and a discharge port; the second discharge port of the separation device 400 is connected to the feed port of the storage device 500, and a second conveying device 600 is connected to the discharge port of the separation device 400. The storage device 500 is used to store the activated sludge separated by the separation device 400, and the second conveying device 600 can convey the surplus sludge with a water content meeting the requirements in the storage device 500 to the subsequent sludge dewatering section for dewatering treatment. Multiple second conveying devices 600 can be provided according to the specific treatment volume. More specifically, the second conveying device 600 can convey the surplus sludge to a sludge dewatering machine. As a specific embodiment, the storage device 500 is a sludge storage tank, and the second conveying device 600 is a sludge screw pump.

[0084] As an alternative embodiment, the system may also be provided with an instrument system and a control system. For example, a sludge flowmeter, a sludge concentration meter and a pressure sensor are provided at the outlet of the first conveying device 200, a liquid level meter is provided in the mixing device 300, and a pressure sensor is provided for the separation device 400. Then, according to the sludge concentration in the mixing device 300 and the sludge concentration meter of the first conveying device 200, the operating flow rate of the first conveying device 200 can be controlled and adjusted through the control system.

[0085] The process flow of the sludge gravity thickening system of the system is as follows: dosing surplus sludge and fillers with a particle size of 50 - 250 microns into a mixing tank with an axial flow stirrer, and fully stirring and mixing them, wherein the residence time is 2 - 4 minutes and the stirring intensity is 100 - 200W / m 3; Then the mixed excess sludge enters the gravity thickening tank. Under the action of gravity and the sludge thickener 110, the sludge descends and the liquid ascends, achieving thickening and stratification to obtain supernatant and sludge layer. The water content of the thickened excess sludge in the sludge layer is 96% - 98%. During mixing, the dosage of the filler should meet the requirement that its concentration in the gravity thickening tank is greater than 500 - 1000 mg / L, where mg / L refers to the mass of the filler / the volume of the gravity thickening tank, so as to achieve better thickening effect. During normal operation, according to the loss situation of the system filler, the filler is regularly supplemented into the system to maintain the filler concentration in the system. In addition, when the filler dosage concentration is higher than 1000 mg / L, the sludge thickener 110 of the gravity thickening tank can adopt a heavy-duty sludge thickener to effectively collect the bottom thickened sludge into the sludge hopper, and a motor with a larger power is selected when choosing the motor type.

[0086] The supernatant can be discharged into the factory sewage pipe network through the water outlet, and the sludge in the sludge layer is transported to the hydrocyclone through the slurry pump for separation of the filler and the excess sludge. Among them, the solid content of the excess sludge entering the hydrocyclone is 2% - 4%, the feeding pressure is 0.25 - 0.35 MPa, the solid content range of the discharge from the sand settling port 430 during separation is 2% - 10%, and the solid content of the excess sludge flowing out from the overflow port 410 is in the range of 2% - 5%. Among them, the solid content = 1 - water content; the recovery rate of the filler is about 90% - 95%.

[0087] The separated filler can be re-injected into the mixing tank to be mixed with the next batch of excess sludge again to achieve recycling. The separated excess sludge can enter the sludge storage tank, and the sludge is sent from the sludge storage tank to the sludge dewatering machine through the sludge screw pump for subsequent dewatering treatment.

[0088] Example 2

[0089] After the upgrading of a certain project, the calculated excess sludge production is 25 tDS / d. There are two existing sludge thickening tanks with a diameter of 15 m and an effective depth of 5 m. After verification, the solid flux after the upgrading is as high as 70.78 kg / m 2 / d, exceeding the specification requirement of 30 - 60 kg / m 2 / d, but there is no available land on site. Therefore, it is considered to use the sludge gravity thickening system as in Example 1. The main design parameters are as follows. This solution can achieve the purpose of improving the thickening effect of the thickening tank with lower equipment investment.

[0090] Designed sludge treatment scale: 25 tDS / d

[0091] Water content of the influent sludge to the thickening tank: 99.2%

[0092] The main newly added equipment parameters of the sludge gravity thickening system solution are shown in Table 1.

[0093] Table 1 Main Equipment Parameters of the New Sludge Gravity Thickening System in the Current Sludge Thickening Tank of a Certain Project

[0094] Number Item Parameter Quantity Remarks 1 Mixing tank <![CDATA[V = 5m 3 , the agitator power N = 1.1KW]]> 2 Two units in use 2 Desander <![CDATA[Q = 20 - 50 m 3 / h]]> 2 Two units in use 3 Slurry pump <![CDATA[Q = 20 - 50 m 3 / h, H = 30 m, N = 15 KW]]> 4 Two units in use and two units in standby 4 Quartz sand <![CDATA[100 - 150 microns, true density 2650 kg / m 3 , uniformity coefficient ≤ 1.7]]> 1.77t 5 HDPE pipe / One batch / 6 Electric control / One set /

[0095] Without the need to add a new thickening tank, the solid flux is 75.8 kg / m 2 / d, the hydraulic retention time is 13.56 h, the moisture content of the thickened sludge is stable at 96.5% - 98%, and the supernatant is relatively clear in appearance.

[0096] The above schematically describes the present utility model and its implementation manners. This description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present utility model, and the actual structure is not limited thereto. Therefore, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the creation of the present utility model, design similar structural manners and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present utility model.

Claims

1. A sludge gravity thickening system, characterized in that: It comprises a mixing device (300), a gravity concentration device (100), and a separation device (400); The mixing device (300) comprises a second feed port and a discharge port; The gravity concentration device (100) comprises a feed inlet, a discharge outlet and a water outlet. The separation device (400) comprises a feed port, a first discharge port and a second discharge port. The mixing device (300) is used to mix the excess sludge and the filler, and the discharge port of the mixing device (300) is connected to the feed port of the gravity concentration device (100); The discharge port of the gravity concentrating device (100) is connected to the feed port of the separation device (400), and the gravity concentrating device (100) is provided with a sludge concentrator (110); The first outlet port of the separation device (400) is connected to the second outlet port of the mixing device (300).

2. The sludge gravity thickening system according to claim 1, characterized in that: The particle size of the filler is 50 to 250 microns.

3. The sludge gravity thickening system according to claim 2, characterized in that: The actual density of the filler is 1300-3500 kg / m 3 .

4. The sludge gravity thickening system according to any one of claims 1 to 3, characterized in that: The filler is one of sand and ore ground fine material.

5. The sludge gravity thickening system according to claim 4, characterized in that: The separation device (400) comprises a plurality of cyclones; The cyclone comprises a mud inlet (420), an overflow port (410) and a sand settling port (430). The mud inlets (420), overflow ports (410) and sand settling ports (430) of the plurality of cyclones are respectively connected via connecting components (480).

6. The sludge gravity thickening system according to claim 4, characterized in that: It also includes a storage device (500), a second conveying device (600), The storage device (500) comprises a feed inlet and a discharge outlet; The second discharge port of the separation device (400) is connected to the feed port of the storage device (500); The discharge port of the storage device (500) is connected to the second conveying device (600).

7. The sludge gravity thickening system according to claim 6, characterized in that: A first conveying device (200) is provided between the discharge port of the gravity concentration device (100) and the feed port of the separation device (400).

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