Self-cleaning hydrodynamic cavitation device

Abstract

The utility model discloses a self-cleaning hydrodynamic cavitation device and relates to the field of sludge treatment. The self-cleaning hydrodynamic cavitation device comprises a backwashing device, and a feeding pipeline, a pore plate cavitator, a sludge conveying pipeline, a rotational flow cavitator and a discharging pipeline which are communicated in sequence; a feeding valve is arranged on the feeding pipeline, and an outlet valve is arranged on the sludge conveying pipeline; the backwashing device comprises a water inlet pipeline and a water drainage pipeline; the water inlet pipeline is communicated with the sludge conveying pipeline between the pore plate cavitator and the outlet valve, and a water inlet valve is arranged on the water inlet pipeline; the drainage pipeline is communicated with the feeding pipeline between the feeding valve and the pore plate cavitator, and a drainage valve is arranged on the drainage pipeline; and the sludge conveying pipeline is also communicated with a medicament conveying pipeline. The self-cleaning hydrodynamic cavitation device disclosed by the utility model can be used for effectively dehydrating sludge; effective self-cleaning can be achieved, and the system stability is high; and energy conservation can be realized while the dehydration effect is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of sludge treatment methods, in particular to a self-cleaning hydraulic cavitation device. Background Art

[0002] With the continuous development of the economy, the requirements for the treatment and disposal of industrial wastewater have gradually deepened, and the market demand for deep dehydration of industrial sludge has increased. The composition of industrial sludge is complex, and the organic matter content of some industrial sludge is as high as 80%, which is difficult to dehydrate. During the sludge dehydration process, the dissolution efficiency of organic matter in the cells directly depends on the cracking effect of the microorganisms in the sludge. The cell wall of the microbial cell is a stable semi-rigid structure that plays a role in protecting the cell, increasing the difficulty of subsequent sludge treatment. The conventional sludge treatment process is difficult to further reduce the water content of the sludge. Therefore, the sludge must be cracked, that is, the semi-rigid structure of the sludge cell wall is destroyed, the sludge floc structure is changed, and the active organic matter in the cell overflows the water phase. The size of the granular sludge is reduced through mechanical pressure and other effects, and the water content of the residual sludge is further reduced, thereby reducing the amount of sludge. The strong hydraulic shear force generated by cavitation can destroy the microbial cell wall to achieve the purpose of cracking the sludge, and the cavitation effect can not only greatly shorten the treatment time, but also greatly improve the treatment effect.

[0003] Ultrasonic cavitation conditioning technology has the characteristics of high energy density and fast sludge decomposition speed, but the choice of ultrasonic power and action time will directly affect the conditioning effect. Low-power, short-time ultrasonic conditioning can improve the dehydration performance, while high-power, long-time ultrasonic conditioning will not only not improve the dehydration performance of sludge, but will have a negative impact on the dehydration performance of sludge, and it is difficult to condition the sludge uniformly. Ultrasonic conditioning of sludge will cause the sludge temperature to continue to rise, and the energy consumption is high, so there are few practical applications.

[0004] Compared with ultrasonic cavitation conditioning devices, hydraulic cavitation has lower action intensity and higher energy efficiency, and has obvious economic advantages over ultrasonic cavitation conditioning. Among them, orifice cavitation, Venturi cavitation and other devices have certain applications in municipal sludge reduction practical projects, but industrial sludge contains many impurities, which can easily block the system and make it difficult to produce a good pretreatment effect. After independent cavitation treatment, the sludge cell wall ruptures and the intracellular water is released, resulting in an increase in the content of protein, polysaccharides, etc. in the sludge, making it more difficult to dehydrate the sludge. Utility Model Content

[0005] In order to solve the problems existing in the above-mentioned prior art, the purpose of the utility model is to provide a self-cleaning hydraulic cavitation device, which can play a significant role in the operational stability of hydraulic cavitation and effectively ensure the hydraulic cavitation effect.

[0006] The utility model provides the following technical solutions:

[0007] The utility model provides a self-cleaning hydraulic cavitation device, comprising a backwashing device and a feed pipe, an orifice plate cavitator, a sludge conveying pipe, a cyclone cavitator and a discharge pipe which are connected in sequence; the feed pipe is provided with a feed valve, and the sludge conveying pipe is provided with an outlet valve; the backwashing device comprises a water inlet pipe and a drainage pipe; the water inlet pipe is connected with the sludge conveying pipe between the orifice plate cavitator and the outlet valve, and the water inlet pipe is provided with a water inlet valve; the drainage pipe is connected with the feed pipe between the feed valve and the orifice plate cavitator, and the drainage pipe is provided with a drainage valve; the sludge conveying pipe is also connected with a pharmaceutical conveying pipe.

[0008] Furthermore, the self-cleaning hydraulic cavitation device also includes a cleaning scraper; the cleaning scraper is arranged at one feeding end of the orifice plate cavitator to further clean the orifice plate cavitator.

[0009] Furthermore, the self-cleaning hydraulic cavitation device also includes a cleaning motor, and the cleaning motor is connected to the cleaning scraper to drive the cleaning scraper to move.

[0010] Furthermore, the orifice plate cavitator comprises an external flange and an internal cavitation orifice plate; the cavitation orifice plate is connected to a feed pipe and a sludge conveying pipe via the flange; and a plurality of through holes with a diameter of 4.5-5.5 mm are provided on the cavitation orifice plate.

[0011] Furthermore, the porosity of the cavitation orifice plate is 30-40%.

[0012] Preferably, the thickness of the orifice plate is 1.5 cm.

[0013] Furthermore, a medicine inlet valve is provided on the medicine delivery pipeline.

[0014] Furthermore, both ends of the cyclone cavitation device are connected to the sludge conveying pipeline; and the discharge pipeline is connected to the middle part of the cyclone cavitation device.

[0015] Furthermore, the cyclone cavitator comprises tapered sections at both ends, and the sludge conveying pipe is connected to the ends of the tapered sections at both ends.

[0016] Furthermore, the cyclone cavitator further comprises a middle communicating pipe, wherein the middle communicating pipe communicates with the tapered sections at both ends; and the discharge pipe communicates with the middle communicating pipe.

[0017] Furthermore, the dehydration quality of the sludge by the orifice plate cavitation device is related to the feed pressure. When the feed pressure is too high, the discharge pressure will increase accordingly, and the pressure difference will also increase significantly. Due to the large pressure difference, a large number of sludge cells will break, which will cause the sludge particle size to decrease after cavitation, and the dichromate index (COD cr) will increase significantly, the sludge viscosity will increase, and the dehydration will deteriorate. When the feed pressure is too low, the pressure difference is insufficient, the flow rate is slow, and the cavitation effect is not obvious. A feed pressure gauge is provided at the feed port of the orifice cavitator, and a discharge pressure gauge is provided at the discharge port of the orifice cavitator; the feed pipeline is connected to a pump for regulating the sludge pressure and flow rate, and the feed pressure of the sludge can be accurately regulated by the feed pressure gauge and the discharge pressure gauge, and the feed pressure of the sludge is controlled at 0.3-0.4MPa, and then the discharge pressure is controlled at 0.1-0.15MPa, and the pressure difference is 0.2-0.3MPa.

[0018] Furthermore, the orifice plate cavitator is made of stainless steel.

[0019] Furthermore, the agent transported in the agent delivery pipeline is selected from one of an inorganic flocculant and an organic flocculant; the inorganic flocculant is selected from at least one of polyferric sulfate, polyaluminum chloride, and polyaluminum ferric chloride; the organic flocculant is selected from at least one of polyquaternary ammonium salt and polyacrylamide.

[0020] Preferably, when the agent is an inorganic flocculant, the dosage ratio of the agent is 3-15% of the dry basis of the sludge; dosage ratio = agent dry powder mass / sludge absolute dry weight; the sludge absolute dry weight is the amount of sludge after removing moisture.

[0021] Preferably, when the agent is an organic flocculant, the dosage ratio of the agent is 0.2-0.3% of the dry basis of the sludge, and the dosage ratio = agent mass / sludge absolute dry weight; the sludge absolute dry weight is the amount of sludge after removing water.

[0022] The beneficial technical effect of the utility model is that the self-cleaning hydraulic cavitation device of the utility model cleans the orifice plate cavitator through the backwashing device, and the cleaning effect is good. Due to the setting of the feed valve and the outlet valve, the orifice plate cavitator is cleaned without affecting other mechanisms. Secondly, a cleaning scraper is set at the feed port of the orifice plate cavitator, and the backwashing device and the cleaning scraper work together to further improve the self-cleaning effect. In addition, the cavitated sludge and flocculant are fully mixed through the cyclone cavitator. The cyclone cavitator is composed of two tapered sections. The sludge enters the cyclone cavitator from one end of the two tapered sections respectively, which can effectively utilize the residual kinetic energy after the previous cavitation, and the mixing effect is better. It can reduce power facilities and achieve energy-saving effects. The utility model can effectively dehydrate industrial sludge with a large amount of impurities and a hydraulic cavitation organic matter content of 60% to 80%. The sludge treated by the utility model is flocculated and plate-frame filtered to achieve a sludge moisture content of less than 55%. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic structural diagram of a self-cleaning hydraulic cavitation device provided in an embodiment of the utility model.

[0025] Figure 2 A schematic structural diagram of a orifice plate cavitator provided in an embodiment of the utility model.

[0026] Figure 3 A process flow chart of treating sludge using a self-cleaning hydraulic cavitation device provided in an embodiment of the utility model.

[0027] Description of the symbols in the figure:

[0028] 11-feed pipe, 12-feed valve, 13-feed pressure gauge, 14-drain valve, 15-drain pipe, 16-cleaning motor, 17-cleaning scraper, 18-orifice cavitator, 19-water inlet valve, 20-water inlet pipe, 21-discharge pressure gauge, 22-outlet valve, 23-medicine feed valve, 24-medicine delivery pipe, 25-cyclone cavitator, 26-discharge pipe, 28-sludge delivery pipe, 181-cavitation orifice plate, 182-flange. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the utility model to clearly and completely describe the technical solution of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0030] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0031] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0032] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Please refer to Figure 1-2 The self-cleaning hydraulic cavitation device shown comprises a cleaning device and a feed pipe 11, a perforated plate cavitator 18, a sludge conveying pipe 27, a cyclone cavitator 25 and a discharge pipe 26 connected in sequence. The sludge conveying pipe 27 is also connected to a reagent conveying pipe 24, which conveys the cavitated sludge and the reagent to the cyclone cavitator 25 for mixing.

[0034] Specifically, the feed pipe 11 is connected to a screw pump (not shown in the figure), and the screw pump can feed the sludge into the self-cleaning hydraulic cavitation device through the feed pipe 11. The screw pump adjusts the feed pressure of the sludge by frequency conversion control. A feed pressure gauge 13 is provided on the feed pipe 11 to detect the feed pressure of the sludge; a discharge pressure gauge 21 is provided between the outlet valve 22 and the orifice cavitator 18 to detect the pressure of the sludge after cavitation; a feed valve 12 is provided on the feed pipe 11, and the feed pressure and flow rate of the sludge can be further controlled by the feed valve 12. The feed pressure gauge 13 is arranged between the feed valve 12 and the orifice cavitator 18.

[0035] Specifically, the orifice plate cavitator 18 is a vertical flow orifice plate cavitator, and the orifice plate cavitator 18 includes an external flange 182 and an internal cavitation orifice plate 181, and the cavitation orifice plate is connected to the feed pipe 11 and the sludge conveying pipe 27 through the flange 182. The cavitation orifice plate 181 is provided with a plurality of through holes with a diameter of 5 mm, and the porosity of the cavitation orifice plate 181 is 35%. The thickness of the cavitation orifice plate 181 is 1.5 cm.

[0036] Specifically, the cleaning device includes a backwashing device and a scraper device; the backwashing device includes an inlet pipe 20 and a drainage pipe 15, one end of the inlet pipe 20 is connected to a high-pressure water pump (not shown in the figure), the inlet pipe 20 is provided with an inlet valve 19, and the drainage pipe 15 is provided with a drainage valve 14; the other end of the inlet pipe 20 is connected to a sludge conveying pipe 27, and the sludge conveying pipe 27 between the inlet pipe 20 and the cyclone cavitator 25 is provided with an outlet valve 22, which can prevent water from flowing into the cyclone cavitator 25 during backwashing; the drainage pipe 15 is connected to the feed valve 12 and the feed pipe 11 between the orifice cavitator 18, and can discharge the sewage after cleaning the orifice cavitator 18.

[0037] Specifically, a discharge pressure gauge 21 is provided on the sludge conveying pipeline 27 between the orifice plate cavitator 18 and the outlet valve 22 .

[0038] Specifically, the scraper device includes a cleaning scraper 17 and a cleaning motor 16. The cleaning scraper 17 is arranged below the cavitation orifice plate 181, and can stir below the cavitation orifice plate 181 to scrape off the sludge accumulated at the entrance of the cavitation orifice plate 181, thereby avoiding blockage caused by sludge accumulation and enhancing the cleaning effect. The cleaning scraper 17 is connected to the cleaning motor 16, and the cleaning motor 16 can control the movement of the cleaning scraper 17.

[0039] Specifically, the sludge conveying pipeline 27 between the outlet valve 22 and the cyclone cavitator 25 is connected to the drug conveying pipeline 24 , and the drug inlet valve 23 is provided on the drug conveying pipeline 24 .

[0040] Specifically, the cyclone cavitator 25 includes tapered sections at the upper and lower ends and a middle connecting pipe. The sludge conveying pipe 27 connects the top and bottom of the cyclone cavitator 25. The middle connecting pipe is connected to the drainage pipe 15. The sludge and the reagent enter the cyclone cavitator 25 from the top and bottom of the cyclone cavitator 25, and are discharged through the middle connecting pipe after being evenly mixed by cyclone collision.

[0041] Specifically, the inner diameter of the middle connecting pipe is DN40 and the length is 10 cm.

[0042] Specifically, the process of using the self-cleaning hydraulic cavitation device of Example 1 to treat sludge is as follows:

[0043] like Figure 3 As shown in the figure, the sludge from the secondary sedimentation tank of the slaughterhouse was tested, and the raw water COD crThe moisture content of the raw mud is 97.35%, and the organic matter of the mud is 81%. The frequency of the screw pump is adjusted to pump the mud from the secondary sedimentation tank into the self-cleaning hydraulic cavitation device. The mud enters the feed pipe 11, the feed valve 12, the outlet valve 22, and the feed valve 23 are opened, and the water inlet valve 19 and the drain valve 14 are closed. The feed pressure gauge shows 0.35MPa, and the mud flow rate is 28m 3 / h, the sludge enters the orifice cavitator 18 for cavitation treatment. Under the action of the orifice cavitator 18, the sludge extracellular polymer (EPS) structure is destroyed, the sludge particle size drops rapidly, the sludge cell wall ruptures, and the water inside the cell is released. After cavitation treatment, the sludge enters the sludge conveying pipeline 27, and the discharge pressure gauge 21 shows 0.1MPa. The polyferric sulfate agent enters the sludge conveying pipeline 27 from the agent conveying pipeline 24 and enters the cyclone cavitator 25 from the top and bottom of the cyclone cavitator 25 together with the sludge. After the high-speed cyclone, the sludge and the agent collide and mix in the middle connecting pipeline. After mixing, the sludge enters the homogenization tank for slow flocculation. The flocculation time is 30min, completing the pretreatment process. After the pretreatment is completed, the sludge is sent to the plate and frame filter press for dehydration by the sludge screw pump, and after conditioning, it is squeezed by a high-pressure diaphragm plate and frame filter press. The dosage of polyferric sulfate is 8% of the dry basis of the sludge.

[0044] During stable operation, if the difference between the feed pressure gauge 13 and the discharge pressure gauge 21 is greater than 0.3MPa, the feed is stopped and the system starts automatic backwashing and cleaning. During backwashing, the feed valve 12 and the outlet valve 22 are closed, and the high-pressure water pump draws water from the sewage plant to backwash the orifice cavitator. The impurities after backwashing are discharged through the drainage pipe 15; at the same time, the cleaning motor 16 is started, driving the cleaning scraper 17 to clean the surface of the orifice cavitator to ensure that the blocked debris can be fully discharged.

[0045] Comparative Example 1

[0046] The difference between this comparative example and Example 1 is that a static mixer is used to replace the cyclone cavitator 25 .

[0047] Comparative Example 2

[0048] The difference between this comparative example and Example 1 is that the orifice plate cavitator 18 is not included.

[0049] Comparative Example 3

[0050] The difference between this comparative example and Example 1 is that the feed pressure is 0.6 MPa and the sludge flow rate is 35 m 3 / h, the discharge pressure is 0.1MPa.

[0051] Comparative Example 4

[0052] The difference between this comparative example and Example 1 is that the feed pressure is 0.2 MPa and the sludge flow rate is 20m 3 / h, the discharge pressure is 0.05MPa.

[0053] The moisture content of the sludge treated in Example 1 and Comparative Examples 1-4 was tested and the filtrate COD was detected. cr , the results are shown in Table 1 below.

[0054] Table 1 Sludge moisture content and filtrate COD treated in Example 1 and Comparative Examples 1-4 cr Test Results

[0055] project Moisture content of dry mud (%) <![CDATA[Filter liquor COD cr > Example 1 53.74 683mg / L Comparative Example 1 56.25 678mg / L Comparative Example 2 68.32 575mg / L Comparative Example 3 70.32 856mg / L Comparative Example 4 65.43 594mg / L

[0056] As shown in Table 1, the water content of the sludge obtained after flocculation and filter pressing dehydration of the sludge treated by the self-cleaning hydraulic cavitation device of the present application is less than 55%, and the filtrate COD cr In comparative example 3, due to the high pressure difference, the hydraulic cavitation wall breaking performance is enhanced, the organic matter inside the sludge is released, and the filtrate COD cr However, due to the high pressure difference, the hydraulic cavitation effect is affected, resulting in poor dehydration effect. Therefore, the present application has strong advantages in both sludge dehydration effect and environmental protection index.

[0057] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the utility model, and these modifications or replacements should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A self-cleaning hydrodynamic cavitation device, characterized in that: It includes a backwashing device and a feed pipe, an orifice plate cavitator, a sludge conveying pipe, a cyclone cavitator and a discharge pipe which are connected in sequence; the feed pipe is provided with a feed valve, and the sludge conveying pipe is provided with an outlet valve; the backwashing device includes an inlet pipe and a drain pipe; the inlet pipe is connected to the sludge conveying pipe between the orifice plate cavitator and the outlet valve, and the inlet pipe is provided with a water inlet valve; the drain pipe is connected to the feed pipe between the feed valve and the orifice plate cavitator, and the drain pipe is provided with a drain valve; the sludge conveying pipe is also connected to a reagent conveying pipe.

2. The self-cleaning hydrodynamic cavitation device according to claim 1, characterized in that: It also includes a cleaning scraper; the cleaning scraper is arranged at one feeding end of the orifice plate cavitator and is used to clean the orifice plate cavitator.

3. The self-cleaning hydrodynamic cavitation device according to claim 2, characterized in that: It also includes a cleaning motor, which is connected to the cleaning scraper and is used to drive the cleaning scraper to move.

4. The self-cleaning hydrodynamic cavitation device according to claim 1, characterized in that: The orifice plate cavitator comprises an external flange and an internal cavitation orifice plate; the cavitation orifice plate is connected to a feed pipe and a sludge conveying pipe through the flange; and a plurality of through holes with a diameter of 4.5-5.5 mm are arranged on the cavitation orifice plate.

5. The self-cleaning hydrodynamic cavitation device according to claim 4, characterized in that: The porosity of the cavitation orifice plate is 30-40%.

6. The self-cleaning hydrodynamic cavitation device according to claim 1, characterized in that: Both ends of the cyclone cavitation device are connected to the sludge conveying pipeline; and the discharge pipeline is connected to the middle part of the cyclone cavitation device.

7. The self-cleaning hydrodynamic cavitation device according to claim 6, characterized in that: The cyclone cavitator comprises tapered sections at two ends, and the sludge conveying pipe is respectively connected with the tapered sections at two ends.

8. The self-cleaning hydrodynamic cavitation device according to claim 7, characterized in that: The cyclone cavitator further comprises a middle communicating pipe, wherein the middle communicating pipe is connected with the tapered sections at both ends; and the discharge pipe is connected with the middle communicating pipe.

9. The self-cleaning hydrodynamic cavitation device according to claim 1, characterized in that: A feed pressure gauge is provided at the feed inlet of the orifice plate cavitator, and a discharge pressure gauge is provided at the discharge outlet of the orifice plate cavitator.

10. The self-cleaning hydrodynamic cavitation device according to any one of claims 1 to 9, characterized in that: The medicine delivery pipeline is provided with a medicine inlet valve.

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