A kind of activated sludge rapid thawing device and method

Abstract

The present invention discloses an activated sludge rapid thawing device and method, the device includes sludge crushing equipment, crushed sludge conveying equipment, sludge thawing equipment, etc. The sludge thawing equipment includes a support frame, a filter cloth, a driving assembly for driving the filter cloth to move, a distributor and at least one sludge thawing unit, and the thawing principle of the sludge thawing unit is pressure hot air thawing. When the device is used to thaw the sludge, the sludge crushing equipment is first used to crush the block sludge into granular sludge to increase the surface area of ​​the sludge; then the subsequent sludge thawing equipment is used to quickly thaw the frozen sludge particles, thereby improving the sludge thawing efficiency, effectively avoiding the problem of secondary mixing of sludge and condensed water during the thawing process, and laying a good foundation for subsequent sludge dehydration and drying; in addition, the device can be arranged in three dimensions to save floor space. At the same time, the thawing process of the frozen sludge belongs to a pure physical state change and will not cause secondary pollution to the surrounding environment.

Description

Technical Field

[0001] The invention belongs to the field of solid waste treatment, and in particular relates to an activated sludge rapid thawing device and method. Background Art

[0002] A large amount of excess activated sludge is generated during the sewage treatment process. The treatment investment and operation cost of excess activated sludge are high, which brings a heavy burden to sewage treatment. Activated sludge is mainly composed of bacteria, viruses, fungi, algae, protozoa and the residues of these organisms after death. It has the characteristics of high cohesion, compressibility and corruption, and is very difficult to handle.

[0003] Sludge freezing is a new method for pre-treatment of sludge developed in recent years. The principle is that after repeated freezing, the sludge can destroy the binding force between sludge and water and the structure of the colloid (similar to the built-in tofu after freezing), so that the colloid destabilizes and condenses and the cell membrane ruptures, so that the water inside the cell that is difficult to remove by mechanical methods is dialyzed to form interstitial water that is easy to remove by mechanical methods, and the sludge particles are quickly settled, and the dehydration rate is significantly improved than before freezing. The advantage of sludge freezing treatment is that no agent needs to be added, which can save the cost of agents, and will not increase the amount of sewage sludge treated in the later period. Combined with the subsequent treatment method of sludge, the deep reduction treatment of sludge is completed. For example, CN210438599U discloses a sludge thawing and preliminary dehydration integrated device. Although the device can separate thawed water from sludge and discharge thawed sewage, the purpose of preliminary dehydration of sludge is achieved. However, its disadvantage is that the frozen sludge on the grid layer is in direct contact with the atmosphere at normal temperature. Due to the large volume and low temperature of the frozen sludge, the water molecules in the atmosphere will condense into condensed water when the sludge slowly thaws. The production of condensed water will increase the time and efficiency of sludge dehydration, thus leading to problems such as low thawing efficiency and long thawing cycle. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an activated sludge rapid thawing device and method. The method utilizes a purely physical process and adopts the process technology of crushing and pressurized hot air erosion thawing, which can effectively reduce the impact of the generation of condensed water on the dehydration process, improve the thawing efficiency of frozen sludge, and lay the foundation for subsequent sludge dehydration and drying.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] The first object of the present invention is to provide an activated sludge rapid thawing device, comprising:

[0007] Sludge crushing equipment, used to crush frozen block sludge into granular sludge;

[0008] A crushed sludge conveying device, wherein the feeding position of the crushed sludge conveying device is located directly below the discharging position of the sludge crushing device;

[0009] A sludge thawing device, comprising a support frame, a filter cloth, a driving assembly for driving the filter cloth to move, a distributor and at least one sludge thawing unit, wherein:

[0010] The distributor is located above the front end of the filter cloth, and the feed port of the distributor is located just below the discharge position of the crushed sludge conveying equipment;

[0011] The sludge thawing unit includes a relatively arranged air hood and a liquid collecting tank, wherein the air hood is located above the filter cloth, and the liquid collecting tank is located below the filter cloth; the top of the air hood is connected to a high-pressure blower through an air pipe, and a valve is installed on the air pipe; the air hood and the liquid collecting tank are both connected to a hydraulic device and installed on a support frame through the hydraulic device, and can move up and down under the drive of the hydraulic device; preferably, the hydraulic device is a hydraulic cylinder. The bottom of the liquid collecting tank is connected to a drain pipe, and a centrifugal pump is installed on the drain pipe; filter cloth side strips are provided at the contact between the filter cloth and the air hood and the liquid collecting tank; the filter cloth side strips are rubber strips, and the width of the rubber strips is 3-10cm. When the crushed frozen sludge is transported to the bottom of the cloth air hood with the filter cloth, the hydraulic device drives the cloth air hood to move down and the liquid collecting tank to move up, so that the bottom of the cloth air hood and the top of the liquid collecting tank are in close contact with the filter cloth edge strips. At this time, the cloth air hood, filter cloth and liquid collecting tank together form a relatively sealed environment. Under the action of the centrifugal pump, a slightly negative pressure state is formed on the lower surface of the crushed frozen sludge; the air generates positive pressure under the action of the high-pressure blower and the temperature rises steadily to form hot air with stable pressure. During this period, no heat source is needed. The general temperature rise range is 20 to 70 degrees Celsius. The hot air enters the cloth air hood through the connected air pipe. The upper surface of the frozen sludge forms a positive pressure state, which increases the pressure difference between the upper and lower surfaces of the crushed frozen sludge, and enables the hot air to continuously and continuously penetrate the gaps between the crushed frozen sludge from top to bottom. Under the continuous erosion of the hot air, the crushed frozen sludge is quickly thawed. The condensed water generated in the thawing process quickly passes through the filter cloth under the dual effects of gravity and pressure difference, and then enters the liquid collecting tank. At the same time, it is transported to the sewage treatment process unit for secondary treatment through a centrifugal pump. This process is a process of pressure hot air thawing, which facilitates the subsequent sludge dehydration and improves the subsequent sludge dehydration efficiency, and can be set in multiple stages.

[0012] The principle of the temperature increase of air through a high-pressure blower is that the air is squeezed by the impeller in the high-pressure blower and discharged at a high speed, thereby generating heat; in addition, because the operation of the blower itself is a series of processes that convert electrical energy and mechanical energy into kinetic energy, coupled with the frictional heat generation principle of the compressed air inside the blower, the temperature of the air passing through the high-pressure blower will increase to a certain extent. In general, high-pressure blowers will increase the air temperature, which is generally regarded as an unfavorable factor in production activities and needs to be properly handled, because if the air temperature is too high, it will have an adverse effect on other equipment or manufactured products in the production activities. However, this patent uses the property of the blower to increase the air temperature, and cleverly applies the air heat to the thawing of frozen sludge. Due to the increase in air temperature, on the one hand, the amount of condensed water generated can be reduced, and on the other hand, the sludge thawing rate can be significantly accelerated, thereby improving the sludge dehydration efficiency.

[0013] In a further solution, a support plate is provided on the top of the liquid collecting tank, which is used to support the filter cloth; a drainage groove and a water permeable hole are opened on the support plate, and the drainage groove provides a flow channel for sewage, so that the water separated from the sludge can flow into the liquid collection tank through the water permeable hole.

[0014] In a further solution, the driving assembly is installed on a support frame, including transmission wheels at both ends of the filter cloth and a plurality of rollers between the transmission wheels; the transmission wheel is connected to a power device for driving its rotation, and the power device includes a reducer and a motor. Driven by the driving assembly, the filter cloth keeps running, thereby driving the sludge particles on its surface to pass through multiple sludge thawing units in sequence, so as to achieve the purpose of gradual thawing.

[0015] In a further solution, a liquid collecting tank is also installed below the distributor, and the liquid collecting tank and the distributor are respectively located on both sides of the filter cloth; a scraper is installed above the filter cloth and near the outlet of the distributor. When the crushed sludge particles are spread on the filter cloth through the distributor, the scraper can make the sludge particles more evenly dispersed on the filter cloth. In this process, the sludge particles may be partially melted, and the water generated by the melting can pass through the filter cloth and then flow into the liquid accumulating tank for collection.

[0016] A further solution also includes a discharge hopper and a plurality of purge air nozzles; the discharge hopper is located below the rear end of the filter cloth and includes a feed port and a first discharge port; the plurality of purge air nozzles are staggered and cross-arranged up and down and are located on both sides of the filter cloth above the feed port of the discharge hopper, and the purge air nozzles are connected to an air compressor. The air compressor delivers compressed air to the purge air nozzles, thereby separating the sludge adhered to or remaining on the surface of the filter cloth from the filter cloth, thereby achieving the effect of cleaning the filter cloth.

[0017] A further solution also includes a shaped sludge conveying device for conveying the frozen sludge to the sludge crushing device. Both the shaped sludge conveying device and the crushed sludge conveying device can use conventional conveyor belt devices to achieve the purpose of conveying materials.

[0018] A further solution also includes a control system for controlling the operation of each device; the control system is a PLC control system, which is a mature technology in the prior art, and the model can be Siemens S7-1500.

[0019] The above-mentioned high-pressure blower, hydraulic device, conveyor belt device, etc. are all commonly used equipment in the market, and their specific working principles are not described here. The above-mentioned opening and closing can be controlled by a manual switch or automatically by a controller. Both methods are conventional control methods in the field, and are not the invention of this device, so they are not described here.

[0020] The second object of the present invention is to provide a method for rapid thawing of activated sludge, which is carried out using the activated sludge rapid thawing device as described above, and comprises the following steps:

[0021] (1) placing the activated sludge into a sludge freezing device for freezing treatment to obtain frozen shaped sludge; and sending the frozen shaped sludge to a curing room for curing;

[0022] (2) The frozen shaped sludge after curing is transported to a sludge crushing device for crushing to obtain crushed sludge; further, the crushing method is cutting and crushing, and the crushed sludge is in the form of sand or small pieces with a particle size within 10 cm.

[0023] (3) The crushed sludge is transported to the sludge thawing equipment for thawing. At the same time, the initial dehydration process of the sludge is achieved during the thawing process.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The thawing device provided by the present invention first utilizes sludge crushing equipment to crush block sludge into granular sludge to increase the surface area of ​​sludge; then utilizes sludge thawing equipment to quickly thaw frozen sludge particles; during the thawing process, a high-pressure blower is utilized to generate hot air with a certain temperature; and the method of crushing and thawing by pressurized hot air erosion is adopted to improve the sludge thawing efficiency, effectively avoid the problem of secondary mixing of sludge and condensed water during the thawing process, and lay a good foundation for subsequent sludge dehydration and drying; in addition, the device can be arranged in three dimensions to save floor space; at the same time, the device is operated in a purely physical state and process, and will not cause secondary pollution to the surrounding environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A front view of the activated sludge rapid thawing device provided by the present invention;

[0027] Figure 2 A top view of the activated sludge rapid thawing device provided by the present invention;

[0028] Figure 3 is a top view of the pallet;

[0029] Figure numerals: 1-shaped sludge conveying equipment, 2-sludge crushing equipment, 3-crushed sludge conveying equipment, 41-support frame, 42-filter cloth, 43-transmission wheel, 44-roller, 45-reducer, 46-motor, 47-distributor, 48-sludge thawing unit, 481-air cloth hood, 482-liquid collecting tank, 483-air pipe, 484-high-pressure blower, 485-valve, 486-hydraulic device, 487-drain pipe, 488-centrifugal pump, 49-support plate, 491-drain groove, 492-water permeable hole, 5-scraper, 6-discharging hopper, 7-purge air nozzle, 8-air compressor. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] It should be understood that the orientations or positional relationships indicated by terms such as “upper”, “lower”, “front”, “back”, “top”, “bottom”, “inside” and “outside” are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation of the present invention.

[0033] refer to Figures 1 to 3 , an activated sludge rapid thawing device, comprising:

[0034] The shaped sludge conveying equipment 1 is used to convey the frozen shaped sludge;

[0035] The sludge crushing device 2 is used to crush the frozen block sludge into granular sludge; the sludge crushing device 2 can be a crusher or a pulverizer with a crushing function. Those skilled in the art can select appropriate related equipment with a crushing function according to actual production needs;

[0036] The crushed sludge conveying device 3, the feeding position of the crushed sludge conveying device 3 is located directly below the discharging position of the sludge crushing device 2;

[0037] The sludge thawing device includes a support frame 41, a filter cloth 42, a driving assembly for driving the filter cloth 42 to move, a distributor 47 and at least one sludge thawing unit 48, wherein:

[0038] The driving assembly is mounted on the support frame 41, and includes transmission wheels 43 located at both ends of the filter cloth and a plurality of rollers 44 located between the transmission wheels 43; the transmission wheel 43 is connected to a power device for driving the rotation thereof, and the power device includes a reducer 45 and a motor 46;

[0039] The distributor 47 is located above the front end of the filter cloth 42, and the feed port of the distributor 47 is located directly below the discharge position of the crushed sludge conveying equipment; a liquid collecting tank 482 is installed below the distributor 47, and the liquid collecting tank 482 and the distributor 47 are respectively located on both sides of the filter cloth 42; a scraper 5 is installed above the filter cloth 42 and near the distributor discharge port. When the crushed sludge particles are spread on the filter cloth through the distributor 47, the scraper 5 can make the sludge particles more evenly dispersed on the filter cloth. In this process, the sludge particles may be partially melted, and the water produced by the melting can pass through the filter cloth and then flow into the liquid accumulation tank for collection.

[0040] The sludge thawing unit 48 comprises a relatively arranged air hood 481 and a liquid collecting tank 482, wherein the air hood 481 is located above the filter cloth, and the liquid collecting tank 482 is located below the filter cloth; the top of the air hood 481 is connected to a high-pressure blower 484 through an air pipe 483, and a valve 485 is installed on the air pipe 483; the air hood 481 and the liquid collecting tank 482 are both connected to a hydraulic device 486 and installed on the support frame 41 through the hydraulic device, and can move up and down under the drive of the hydraulic device 486; preferably, the hydraulic device 486 is a hydraulic cylinder. The bottom of the liquid collecting tank 482 is connected to a drain pipe 487, and a centrifugal pump 488 is installed on the drain pipe 487; the filter cloth 42 is provided with a filter cloth edge strip at the contact point with the air hood 481 and the liquid collecting tank 482; the filter cloth edge strip is a rubber strip, and the width of the rubber strip is 3-10 cm. In a further solution, a support plate 49 is provided on the top of the liquid collecting tank 482, and the support plate 49 is used to support the filter cloth; a drainage groove 491 and a water permeable hole 492 are opened on the support plate 49, and the drainage groove 491 provides a flow channel for sewage, so that the water separated from the sludge can flow into the liquid collection tank through the water permeable hole 492.

[0041] As a preferred technical solution, the activated sludge rapid thawing device also includes a discharge hopper 6 and a plurality of purge air nozzles 7; the discharge hopper 6 is located below the rear end of the filter cloth and includes a feed port and a discharge port; the plurality of purge air nozzles 7 are staggered and cross-arranged up and down and are located on both sides of the filter cloth above the feed port of the discharge hopper, and the purge air nozzles 7 are connected to an air compressor 8. The air compressor 8 delivers air to the purge air nozzles 7, thereby separating the sludge adhered to or remaining on the surface of the filter cloth from the filter cloth, thereby achieving the effect of cleaning the filter cloth.

[0042] The working process of the above-mentioned activated sludge rapid thawing device provided by the present invention is as follows:

[0043] (1) Start-up of sludge crushing equipment;

[0044] (2) The shaped sludge conveying equipment is started to convey the frozen shaped sludge to the sludge crushing equipment;

[0045] (3) The crushed sludge conveying equipment is started to convey the crushed sludge to the distributor;

[0046] (4) The air compressor starts and the purge nozzle begins to clean the filter cloth surface;

[0047] (5) Start the motor, and the filter cloth moves horizontally driven by the transmission wheel;

[0048] (6) As the filter cloth moves horizontally, the crushed frozen sludge in the distributor is spread on the filter cloth; at the same time, under the action of the scraper, the crushed frozen sludge is spread evenly, flatly and regularly;

[0049] (7) When the horizontal movement distance of the filter cloth reaches the set value, the motor stops, the liquid collecting tank moves upward and comes into close contact with the lower surface of the filter cloth, and at the same time, the cloth air hood moves downward and comes into close contact with the upper surface of the filter cloth;

[0050] (8) The centrifugal pump starts to transport the water in the accumulation tank;

[0051] (9) When the centrifugal pump working time reaches the set value, the valve on the air hood opens, and the high-pressure blower starts to deliver hot air with stable pressure to the surface of the crushed frozen sludge on the filter cloth; after a period of time, the high-pressure blower is turned off;

[0052] (10) Step (9) is repeated multiple times. When the number of cycles of step (9) reaches a set value, the centrifugal pump stops working, the liquid sump moves downward and is closely separated from the lower surface of the filter cloth, and the cloth air hood moves upward and is separated from the upper surface of the filter cloth;

[0053] (11) Steps (1) to (10) are performed cyclically, with multiple levels set;

[0054] (12) When the thawed sludge moves with the filter cloth to the top of the discharge hopper, it falls into the discharge port of the discharge hopper under the action of gravity;

[0055] (13) Steps (1) to (11) are repeated in a cycle until there is no sludge in the sludge crushing equipment and the equipment is stopped.

Claims

1. A method for rapid thawing of activated sludge, characterized in that: It is carried out using an activated sludge rapid thawing device and includes the following steps: (1) The activated sludge is placed in a sludge freezing device for freezing treatment to obtain frozen shaped sludge; the frozen shaped sludge is sent to a curing room for curing; (2) transporting the cured frozen shaped sludge to a sludge crushing device for crushing to obtain crushed sludge; (3) The crushed sludge is transported to the sludge thawing equipment for thawing. At the same time, the initial dehydration process of the sludge is achieved during the thawing process; The activated sludge rapid thawing device comprises: Sludge crushing equipment, used to crush frozen block sludge into granular sludge; A crushed sludge conveying device, wherein the feeding position of the crushed sludge conveying device is located directly below the discharging position of the sludge crushing device; A sludge thawing device, comprising a support frame, a filter cloth, a driving assembly for driving the filter cloth to move, a distributor and at least one sludge thawing unit, wherein: The distributor is located above the front end of the filter cloth, and the feed port of the distributor is located just below the discharge position of the crushed sludge conveying equipment; The sludge thawing unit comprises an air hood and a liquid collecting tank which are arranged opposite to each other, wherein the air hood is located above the filter cloth and the liquid collecting tank is located below the filter cloth; the bottom of the liquid collecting tank is respectively connected with a drainage pipe, and a centrifugal pump is installed on the drainage pipe; The top of the air distribution hood is connected to a high-pressure blower through an air pipe; The air distribution hood and the liquid collecting tank are both connected to a hydraulic device and are installed on the support frame through the hydraulic device, and can move up and down under the drive of the hydraulic device.

2. The method for rapid thawing of activated sludge according to claim 1, characterized in that: A liquid collecting trough is also installed below the distributor, and the liquid collecting trough and the distributor are respectively located on both sides of the filter cloth; a scraper is installed above the filter cloth and near the outlet of the distributor.

3. The method for rapid thawing of activated sludge according to claim 2, characterized in that: The contact points between the filter cloth, the cloth air cover and the liquid collecting tank are provided with filter cloth side strips; the filter cloth side strips are rubber strips with a width of 3-10 cm.

4. The method for rapid thawing of activated sludge according to claim 3, characterized in that: A support plate is provided on the top of the liquid collecting tank, and a drainage groove and a water permeable hole are provided on the support plate.

5. The method for rapid thawing of activated sludge according to any one of claims 1 to 4, characterized in that: It also includes a discharge hopper and multiple purge air nozzles; the discharge hopper is located below the rear end of the filter cloth, and includes a feed port and a first discharge port; the multiple purge air nozzles are staggered and cross-arranged up and down and are located on both sides of the filter cloth above the feed port of the discharge hopper, and the purge air nozzles are connected to an air compressor.

6. The method for rapid thawing of activated sludge according to claim 5, characterized in that: The driving assembly is installed on the support frame, and includes transmission wheels located at both ends of the filter cloth and a plurality of rollers located between the transmission wheels; the transmission wheel is connected to a power device for driving the rotation thereof; the power device includes a reducer and a motor.

7. The method for rapid thawing of activated sludge according to claim 1, characterized in that: A valve is installed on the air pipe.

8. The method for rapid thawing of activated sludge according to claim 1, characterized in that: Also included is a shaped sludge conveying device for conveying the frozen sludge to the sludge crushing device.

9. The method for rapid thawing of activated sludge according to claim 1, characterized in that: In step (2), the crushing method is cutting and crushing, and the crushed sludge is in the form of sand or small pieces with a particle size of less than 10 cm.

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