A built-in centrifugal trigger type spray stirring shaft cleaning device

Abstract

This invention relates to a centrifugal-triggered spray cleaning device for an agitator shaft, installed within an agitator. The agitator shaft contains a stirring shaft with agitator blades. A fluid channel is located within the stirring shaft, with its upper end serving as a liquid inlet and its lower end communicating with an annular spray structure. The fluid channel houses a centrifugal-triggered valve assembly comprising centrifugal blocks, a return spring, an elastic pin, and a ball valve core. The return spring's elastic force causes the heads of two centrifugal blocks to abut against each other. Each centrifugal block's head has a limiting inclined surface. The ball valve core has an axial locking through-hole communicating with the flow channel. The front end of the elastic pin rests against the limiting inclined surface, and its rear end can move within the ball valve core along the length of the axial locking through-hole. This device relies on the centrifugal force generated by the centrifugal blocks as the agitator shaft's rotational speed changes to drive the valve core's opening and closing, controlling the annular spray structure to spray water onto the stirring blades for cleaning. The centrifugal-triggered valve assembly does not contain any electronic devices; it is driven solely by the main speed control of the agitator, resulting in a low failure rate and long service life.

Description

Technical Field

[0001] This invention belongs to the technical field of mixing equipment, and in particular relates to a cleaning device for a mixing shaft with built-in centrifugal trigger spray. Background Technology

[0002] After a period of operation, sludge, fibrous materials, and other impurities will accumulate on the mixing blades and inner walls of the mixing equipment commonly used in wastewater treatment plants. These deposits will reduce mixing efficiency, increase motor load, and in severe cases, even cause the equipment to shut down.

[0003] Currently, there are two main ways to handle this type of problem. One is to manually flush with a high-pressure water gun after shutdown, which is cumbersome, affects continuous production, and is physically demanding for workers. The other is to install a separate spray pipe on the tank and control the flushing through a solenoid valve or timer. This method has several problems: first, the spray pipe is external, taking up space, and has many pipe joints, making it prone to leaks; second, it relies on electronic sensors or program controllers, which have a high failure rate in humid and corrosive wastewater environments; and third, the flushing timing and intensity cannot be automatically adjusted according to the actual level of dirt, resulting in either insufficient flushing or wasted water resources.

[0004] In the prior art, for example, Chinese invention patent CN220514100U discloses a stirring structure with cleaning spray in a granulator, which has two spray modes: dynamic and static. However, mode switching still requires the intervention of an electronic control system. Chinese invention patent CN224236693U discloses a spray device for a mixing tank, which combines the spray pipe with the stirring shaft, but the start and stop of the spray still require external control. None of these solutions solve the problem of achieving purely mechanical adaptive triggering without electronic control. Summary of the Invention

[0005] The purpose of this invention is to provide a cleaning device for a stirring shaft with built-in centrifugal trigger spray, which solves the technical problems mentioned in the background art.

[0006] The technical solution adopted by this invention to solve its technical problem is as follows: A stirring shaft cleaning device with a built-in centrifugal trigger spray is provided, installed inside a stirring device. The stirring device contains a stirring shaft with several stirring blades on its lower outer circumference. The stirring shaft is a hollow shaft, and the cavity inside the stirring shaft serves as a fluid channel. The upper end of the fluid channel is the liquid inlet, and the lower end communicates with an annular spray structure. The annular spray structure has several nozzles arranged towards the stirring blades. A centrifugal trigger valve assembly is provided inside the fluid channel. The centrifugal trigger valve assembly includes a centrifugal block, a return spring, an elastic pin, and a ball valve core. A pair of radial grooves are formed along the radial direction on the shaft wall of the stirring shaft. Two sets of centrifugal blocks and the return spring are respectively disposed in the two radial grooves. The elastic force of the return spring causes the head ends of the two centrifugal blocks to meet. The centrifugal blocks have a limiting inclined surface at their head end. The ball valve core is fixed inside the fluid channel. An axial locking through hole is opened inside the ball valve core along the axial direction of the stirring shaft. The axial locking through hole communicates with the outer guide channel at the middle position. The front end of the elastic pin abuts against the limiting inclined surface, and the rear end of the elastic pin can move inside the ball valve core along the length direction of the axial locking through hole. When the front ends of the two centrifugal blocks remain abutting due to insufficient centrifugal force, the rear end of the elastic pin is located in the axial locking through hole and blocks the fluid channel. When the front ends of the two centrifugal blocks separate due to increased centrifugal force, the distance between the limiting inclined surfaces increases accordingly, causing the rear end of the elastic pin to move out of the axial locking through hole and the guide channel to open, thereby opening the entire fluid channel. The nozzle sprays water onto the stirring blade.

[0007] Preferably, the liquid inlet is connected to a water collection tank located at the bottom of the stirring device via a liquid inlet pipe, and the liquid inlet is connected to the liquid inlet pipe via a rotary joint.

[0008] Preferably, the inlet pipe is provided with a self-closing reflux port, and the self-closing reflux port is provided with a one-way filter and a check valve.

[0009] Preferably, a filter screen is provided on the surface of the water collection tank that connects to the stirring device.

[0010] Preferably, the annular spray structure is fixed to the outer periphery of the lower end of the stirring shaft.

[0011] Preferably, the annular spray structure includes several spray units, the number of which is 2 to 5 sets, and the spray units are evenly distributed around the stirring shaft as the center.

[0012] Preferably, each spray unit has 3 to 8 nozzles, and the nozzles are arranged in parallel orientations.

[0013] Preferably, the width of the centrifuge block is greater than the inner diameter of the fluid channel.

[0014] The beneficial effects are as follows: This device relies on the centrifugal force generated by the centrifugal blocks as the stirring shaft rotates to drive the valve core to open and close. It is driven solely by the main control speed of the stirring equipment. The centrifugal trigger valve assembly does not have any electronic sensors, solenoid valves, or program controllers. It has a low failure rate and long service life in humid and highly corrosive sewage environments and is also suitable for explosion-proof areas. The cleaning intensity is positively correlated with the degree of dirt, without wasting water resources. The centrifugal trigger valve and spray ring are both integrated inside the hollow stirring shaft, without external pipelines, making installation and modification convenient and allowing direct replacement of the original stirring shaft. The spray water source is taken from the clarified water at the bottom of the tank and flows back into the tank after cleaning, achieving zero additional water consumption. Compared with external high-pressure water gun washing, the water saving rate can reach more than 75%.

[0015] In addition, the annular spray structure can serve as an additional mixing blade besides the traditional mixing blades, forming a coaxial double-blade mixing structure to improve the mixing effect. Attached Figure Description

[0016] Figure 1 A schematic diagram of the cleaning device for the stirring shaft with built-in centrifugal trigger spray; Figure 2 for Figure 1 Enlarged view of the blockage status of the centrifugal trigger valve assembly; Figure 3 for Figure 2 Sectional view of AA; Figure 4 This is an enlarged view of the centrifugal trigger valve assembly in the on / off state.

[0017] Among them, 1-stirring shaft; 11-fluid channel; 12-radial chute; 2-centrifugal trigger valve assembly; 21-centrifugal block; 22-reset spring; 23-elastic pin; 24-ball valve core; 25-axial locking through hole; 26-limiting inclined surface; 27-guide flow channel; 3-annular spray structure; 4-self-closing reflux interface; 41-one-way filter screen; 42-check valve; 5-stirring blade; 6-tank body; 61-water collection tank; 62-reflux pipeline; 7-rotary joint.

[0018] The same markings in each diagram represent the same component. Detailed Implementation

[0019] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0020] like Figure 1As shown, this embodiment provides a cleaning device for a stirring shaft with built-in centrifugal trigger spray, which is installed inside the tank 6 of a stirring device such as a sewage treatment stirring tank.

[0021] Taking a conventional mixing device as an example, the mixing shaft 1 is made of 304 stainless steel, with an outer diameter of 80mm and an inner fluid channel 11 diameter of 30mm. The lower end of the mixing shaft 1 is welded closed, and the upper end is connected to the output shaft of the drive motor via a flange. Three mixing blades 5, arranged at 120°, are welded to the outer wall of the mixing shaft 1; the blades are made of 316L stainless steel. This application is also applicable to other specifications of mixing devices, provided that the mixing shaft 1 used in the equipment has sufficient space for modification; further details are omitted here.

[0022] The centrifugal trigger valve assembly 2 is installed in the lower section of the inner cavity of the stirring shaft 1. See details below. Figure 2 , 3 4. A radial groove 12 is provided on the shaft wall of the stirring shaft 1. The centrifugal block 21 is a symmetrical counterweight made of brass, with a single block weighing approximately 120g. It can slide along the radial groove 12. The width of the centrifugal block 21 is greater than the inner diameter of the fluid channel 11. Under normal conditions, the fluid channel 11 is locked by the centrifugal block 21, preventing water flow. The return spring 22 is a stainless steel compression spring with a wire diameter of 2mm, a free length of 40mm, a pre-compression of 8mm, and a pre-tightening force of approximately 45N. One end of the return spring 22 is fixed to the centrifugal block 21, and the other end is fixed to the inner wall of the stirring shaft 1. The elastic pin 23 is a quenched steel pin with a diameter of 4mm. One end abuts against the limiting inclined surface of the centrifugal block 21, and the other end is inserted into the axial locking through hole 25 of the ball valve core 24. The return spring 22 limits the retraction stroke of the centrifugal block 21. Even if the centrifugal block 21 retracts to its maximum position, the maximum distance between the limiting inclined surfaces at its head end is still less than the maximum diameter of the elastic pin 23, preventing the elastic pin from falling out after passing through the gap created by the separation of the centrifugal block 21. The ball valve core 24 is a stainless steel ball with a diameter of 20mm, which is fixed in the middle and lower sections of the fluid channel 11 by means of steps, extrusion, etc. The ball valve core 24 has a channel in the middle including an axial locking through hole 25 and a flow channel 27. The axial locking through hole 25 is normally locked by the elastic pin 23, and water cannot pass through.

[0023] In this embodiment, the annular spray structure 3 is welded to the lower outer wall of the stirring shaft 1, located below the stirring blades 5. The annular spray structure 3 includes three sets of spray units, evenly distributed along the circumference at 120°, corresponding one-to-one with the stirring blades 5. Each set of spray units is machined with six nozzles, each with a nozzle orifice diameter of 0.25mm, and the spray direction forms a 45° angle with the horizontal plane, pointing towards the root of the stirring blades 5. In other embodiments, the specific arrangement of the annular spray structure 3 can be adjusted according to the situation.

[0024] The self-closing reflux interface 4 is installed on the top of the stirring shaft 1 and connected to the reflux pipe 62 via a rotary joint 7. The rotary joint 7 is an existing device, mainly composed of a stationary shell, a rotating rotor that rotates synchronously with the stirring shaft, a dynamic and static sealing friction pair, a spring preload mechanism, and a support bearing. The stationary shell is connected to the fixed inlet pipe, and the rotating rotor is connected to the inlet end of the stirring shaft. It can smoothly guide the fluid in the inlet pipe into the rotating hollow stirring shaft while the stirring shaft is continuously rotating, avoiding twisting and entanglement of the pipe, realizing continuous fluid transport between the dynamic and static components, and ensuring smooth water flow. The other end of the reflux pipe 62 is connected to the water collection tank 61 at the bottom of the tank 6. The surface of the water collection tank 61 that communicates with the inside of the stirring equipment is equipped with an 80-mesh stainless steel filter screen to filter and prevent dirt from entering the fluid channel 11. Furthermore, the self-closing reflux interface 4 is equipped with a one-way filter screen 41 and a check valve 42 to ensure that the water flow can only flow from the water collection tank to the stirring shaft 1, preventing backflow.

[0025] The working process of this embodiment is as follows: During normal operation of the mixing equipment, the motor drives the mixing shaft 1 to rotate at a speed of 60 to 100 rpm. At this time, the centrifugal force on the centrifugal block 21 is approximately 30 to 45 N, which is less than the preload of the return spring 22 (45 N), and the centrifugal block 21 remains at the inner end of the radial groove 12. Under the pressure of the inclined surface of the centrifugal block 21, the elastic pin 23 engages with the axial locking through hole 25 of the ball valve core 24, locking the ball valve core 24 and closing the axial locking through hole 25. At this time, the mixing shaft only performs the mixing function and does not spray.

[0026] As the amount of sludge adhering to the stirring blades 5 gradually increases, the stirring resistance increases, and the motor load current rises. Under the constant power control of the frequency converter, the speed automatically increases. When the speed reaches 120 rpm, the centrifugal force on the centrifugal block 21 is about 65 N, which exceeds the preload of the return spring 22. The centrifugal block 21 slides outward about 6 mm along the radial groove 12. The elastic pin 23 disengages from the axial locking through hole 25 of the ball valve core 24 under the action of water pressure (about 0.3 MPa) and its own gravity. The clarified water in the water collection tank 61 at the bottom of the tank 6 enters the fluid channel 11 through the return pipe 62 and the self-closing return interface 4, and then enters the annular spray structure 3 through the axial locking through hole 25. It is sprayed out from eighteen nozzles at the same time, forming a fan-shaped jet to rinse the root of the stirring blades 5.

[0027] When the stirring shaft rotates at high speed with the motor, the water inside the stirring shaft 1 moves synchronously with the shaft, flowing towards the outer edge of the shaft under centrifugal force, creating a local low-pressure zone in the hollow shaft core area. The clarified water in the water collection tank 61 at the bottom of the tank is automatically forced into the inner cavity fluid channel 11 through the preset return pipe 62 under the action of pressure difference, completing the initial water intake process. This process is completely consistent with the self-priming principle of a centrifugal pump. The water entering the inner cavity fluid channel 11 continues to rotate at high speed with the shaft, accelerating towards the radially outer side of the shaft under the drive of centrifugal force, continuously increasing the kinetic energy of the water. When the water flow path is guided to the area near the annular spray structure 3, the high-speed flowing water converts kinetic energy into pressure energy under the constraint of the flow channel, forming a working water pressure sufficient to push the elastic pin 23 downwards, keeping the ball valve core 24 open and spraying water from the nozzle. No external booster equipment is needed to provide additional power throughout the process.

[0028] During the rinsing process, the sludge is peeled off, the stirring resistance gradually decreases, and the motor speed drops. When the speed drops below 120 rpm, the centrifugal block 21 returns to its original position under the action of the return spring 22, the elastic pin 23 re-engages into the axial locking through hole 25 of the ball valve core 24, the ball valve core 24 closes, and the spraying stops.

[0029] Example 2 is basically the same in structure as Example 1, except that the preset trigger speed of the centrifugal trigger valve assembly 2 is adjusted to 150 rpm, the wire diameter of the return spring 22 is increased to 2.5 mm, and the preload is increased to about 70 N. This example is suitable for working conditions where the stirring medium has high viscosity and the normal stirring speed is between 100 and 130 rpm, such as stirring high-viscosity materials in food fermentation tanks or pharmaceutical reaction vessels.

[0030] Example 3 is basically the same in structure as Example 1, except that the nozzle 32 orifice diameter of the annular spray structure 3 is adjusted to 0.35mm, and the number of nozzles 32 is reduced to four per group, for a total of twelve nozzles. This example is suitable for wastewater treatment scenarios with poor water quality and high suspended solids content. The larger nozzle orifice diameter can reduce the risk of clogging and reduce the processing difficulty of the spray ring.

Claims

1. A built-in centrifugal trigger spray cleaning device for a stirring shaft, installed inside a stirring device, wherein the stirring device contains a stirring shaft, and the lower outer circumference of the stirring shaft is provided with a plurality of stirring blades, characterized in that, The stirring shaft is a hollow shaft, and the cavity inside the stirring shaft serves as a fluid channel. The upper end of the fluid channel is the liquid inlet, and the lower end communicates with an annular spray structure. The annular spray structure is provided with several nozzles arranged towards the stirring blades. The fluid channel is equipped with a centrifugal trigger valve assembly, which includes a centrifugal block, a return spring, an elastic pin, and a ball valve core. A pair of radial grooves are formed on the shaft wall of the stirring shaft. Two sets of centrifugal blocks and the return spring are respectively disposed within the two radial grooves. The elastic force of the return spring causes the head ends of the two centrifugal blocks to abut against each other. The head ends of the centrifugal blocks are provided with limiting inclined surfaces. The ball valve core is fixed inside the fluid channel, and an axial locking through hole is formed inside the ball valve core along the axial direction of the stirring shaft. The axial locking through hole communicates with the outer guide channel at the middle section. The front end of the elastic pin abuts against the limiting inclined surface, and the rear end of the elastic pin can move within the ball valve core along the length direction of the axial locking through hole. When the front ends of the two centrifugal blocks remain in opposition due to insufficient centrifugal force, the rear end of the elastic pin is located in the axial locking through hole, blocking the fluid channel; when the front ends of the two centrifugal blocks separate due to increased centrifugal force, the distance between the limiting inclined surfaces increases accordingly, causing the rear end of the elastic pin to move out of the axial locking through hole and the guiding flow channel to be open, thereby opening the entire fluid channel, and the nozzle sprays water onto the stirring blade.

2. The agitator shaft cleaning device with built-in centrifugal trigger spray according to claim 1, characterized in that, The liquid inlet is connected to the water collection tank located at the bottom of the stirring device via a liquid inlet pipe, and the liquid inlet is connected to the liquid inlet pipe via a rotary joint.

3. The agitator shaft cleaning device with built-in centrifugal trigger spray according to claim 2, characterized in that, The inlet pipe is equipped with a self-closing reflux port, and the self-closing reflux port is equipped with a one-way filter and a check valve.

4. The agitator shaft cleaning device with built-in centrifugal trigger spray according to claim 2, characterized in that, A filter screen is provided on the surface of the water collection tank that connects to the stirring equipment.

5. The cleaning device for a stirring shaft with built-in centrifugal trigger spray according to claim 1, characterized in that, The annular spray structure is fixed to the lower outer periphery of the stirring shaft.

6. The agitator shaft cleaning device with built-in centrifugal trigger spray according to claim 1, characterized in that, The annular spray structure includes several spray units, with the number of spray units being 2 to 5 sets. The spray units are evenly distributed around the stirring shaft as the center.

7. A cleaning device for a stirring shaft with built-in centrifugal trigger spray according to claim 6, characterized in that, Each spray unit has 3 to 8 nozzles, and the nozzles are arranged in parallel orientations.

8. A cleaning device for a stirring shaft with built-in centrifugal trigger spray according to claim 1, characterized in that, The width of the centrifuge block is greater than the inner diameter of the fluid channel.

Images