Foam concrete mixing device with protection mechanism

Abstract

This invention discloses a foamed concrete mixing device with a protection mechanism, comprising a base frame, a mixing tank, a liquid distribution assembly, a harmonic liquid supply assembly, and a monitoring system. The mixing tank is rotatably connected to the base frame, and the monitoring system, a feeding hopper, and a discharge hopper are mounted on the mixing tank. Inside the mixing tank are mixing blades and independently rotating mixing paddles, connected to a mixing paddle shaft, which is connected to a mixing drive motor. A roller ring is circumferentially mounted on the mixing paddle, and abutment components are mounted on the surface of the roller ring, with ball bearings rotatably connected to the abutment components. The liquid distribution assembly includes a fixed ring groove, a liquid distribution ring, and a rubber ball cap. The fixed ring groove is slidably connected to the liquid distribution ring and is located on the surface of the base frame and connected to the harmonic liquid supply assembly. The surface of the liquid distribution ring is equipped with a rubber ball cap, and the ball bearings slidably abut against the surface of the liquid distribution ring. This invention enables staged mixing, flexibly protects the foam structure, achieves quantitative multi-point injection of foaming agent, and possesses intelligent monitoring and protection functions, improving its mixing quality and system operational stability.

Description

Technical Field

[0001] This invention pertains to foamed concrete mixing devices, specifically a foamed concrete mixing device with a protection mechanism. Background Technology

[0002] Foamed concrete is a lightweight, porous building material made from a mixture of cement, water, foaming agent, fine aggregate, and other components. It features thermal insulation, light weight, and high fluidity, and is widely used in ground leveling, road backfilling, and building insulation layers. Its performance stability largely depends on the uniformity of foam distribution and structural integrity within the concrete, and the mixing process is one of the key steps determining foam retention rate and concrete quality.

[0003] In existing technologies, foamed concrete mixing typically employs horizontal or vertical single-chamber mixing devices. These devices often have the following typical characteristics: a fixed mixing tank with a high-speed rotating mixing blade inside for mixing cement slurry and foam; foaming agent is usually injected into the tank or slurry through a centralized nozzle, and foam dispersion is achieved through the high-speed shearing of the mixing blade; however, the adjustment of process parameters during the mixing process mainly relies on manual judgment, lacking a closed-loop feedback control system.

[0004] Limited by the above structure and process, existing foam concrete mixing equipment has many technical problems in practical applications, mainly reflected in the following aspects: (1) Traditional mixing equipment cannot control the slurry mixing and foam mixing process in stages. Foam is often added in advance during high-speed slurry mixing, and is subjected to violent stirring and shearing, resulting in a large number of ruptured bubbles, increased concrete density, decreased lightweight properties, and poor product consistency. (2) Most existing equipment injects foaming agent into the mixing chamber through centralized nozzles. The foam distribution is prone to local aggregation. In addition, uneven mixing will cause the foam density in some areas to be too high and be sheared and destroyed, forming a "foam collapse" phenomenon, which reduces the overall stability of concrete. (3) Current devices usually lack key sensing mechanisms such as foam injection volume monitoring, cylinder temperature monitoring, and stirring load detection. They rely only on fixed time settings and manual experience operation, and cannot dynamically adjust the operating parameters in real time according to the foam status. When the foam is abnormal or the stirring load changes drastically, the device cannot respond in time, which poses a safety hazard and is prone to product batch non-compliance.

[0005] In summary, existing foamed concrete mixing equipment still has significant limitations in terms of structural design and process control, making it difficult to meet the increasingly stringent engineering application requirements for foam retention rate, uniformity, and product consistency. Therefore, there is an urgent need for a foamed concrete mixing device that can perform staged mixing, flexibly protect the foam structure, achieve quantitative multi-point injection of foaming agent, and has intelligent monitoring and protection functions, in order to fundamentally improve its mixing quality and system operational stability. Summary of the Invention

[0006] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a foam concrete mixing device that can mix in stages, flexibly protect the foam structure, realize quantitative multi-point injection of foaming agent, and has a protection mechanism.

[0007] Technical Solution: The present invention discloses a foamed concrete mixing device with a protection mechanism, comprising a base frame, a mixing tank, a liquid distribution assembly, a harmonic liquid supply assembly, and a monitoring system. The mixing tank is rotatably connected to the base frame, and the monitoring system, a feeding hopper, and a discharging hopper are installed on the mixing tank. The mixing tank contains a stirring blade and an independently rotating stirring paddle. The stirring paddle is connected to a stirring paddle shaft, which is connected to a stirring drive motor. A roller ring is circumferentially arranged on the stirring paddle, and several abutment components are arranged on the surface of the roller ring. Ball bearings are rotatably connected to the abutment components. The liquid distribution assembly includes a fixed ring groove, a liquid distribution ring, and rubber ball caps. The fixed ring groove is slidably connected to the liquid distribution ring and is located on the surface of the base frame and connected to the harmonic liquid supply assembly. Several rubber ball caps are arranged on the surface of the liquid distribution ring, and the ball bearings slide against the surface of the liquid distribution ring.

[0008] Furthermore, the surface of the liquid distribution ring is provided with several liquid guiding septa for unidirectional introduction of concrete foaming agent from the liquid distribution ring into the inner cavity of the rubber ball cap.

[0009] Furthermore, the stirring blades are symmetrically distributed on both sides of the stirring paddle.

[0010] Furthermore, the roller ring is equipped with several helical blade-shaped stirring blades made of flexible material. The roller ring slides against the inner wall of the mixing tank.

[0011] Furthermore, the rubber ball cap is a hemispherical rubber cover with an internal hemispherical cavity and a drainage hole. As the ball rotates with the roller, it periodically contacts and compresses the rubber ball cap, causing it to deform. This allows the concrete foaming agent inside the rubber ball cap to be extruded sequentially through the drainage hole.

[0012] Furthermore, the harmonic liquid supply assembly includes a wave ring, a liquid tank, an elastic push rod, and a diaphragm. The wave ring is fixedly fitted onto the surface of the stirring tank. The upper and lower ends of the liquid tank are respectively provided with elastic push rods and diaphragms, and the liquid tank is fixed to the surface of the fixed ring groove. Preferably, the diaphragm is a rubber component.

[0013] Furthermore, the wave rings and the surface are alternately arranged with wave crests and troughs.

[0014] Furthermore, the liquid tank is connected to the fixed ring tank through the liquid delivery pipe, and the liquid tank is equipped with an inlet pipe for the concrete foaming agent to enter. Both the liquid delivery pipe and the inlet pipe are equipped with one-way valves.

[0015] Furthermore, a bearing bracket is provided on the surface of the base frame, and a rolling drive motor for driving the bearing bracket to rotate is provided on the base frame. The rotation of the mixing tank is achieved by the bearing bracket contacting the surface of the mixing tank.

[0016] Furthermore, the monitoring system includes a data acquisition module, a display module, and a feedback control module; the data acquisition module transmits real-time monitoring data to the feedback control module; the display module is used to graphically display the foam injection flow rate, stirring load, cylinder temperature, and liquid level change curves; the feedback control module is used to automatically adjust the stirring paddle speed and concrete foaming agent injection speed based on the real-time monitoring data, and trigger automatic shutdown protection or stirring shaft locking when the foam flow rate suddenly drops or the stirring load is abnormal, to avoid foam structure damage and material waste.

[0017] Furthermore, the feedback control module includes a PLC main control unit, a motor frequency converter, and an electromagnetic proportional valve control circuit.

[0018] Furthermore, the mixing tank has a spindle-shaped cylindrical structure.

[0019] Furthermore, the liquid distribution ring is fixed inside the mixing tank.

[0020] Working principle: During the foam mixing stage, the agitator rotates independently at low speed under the action of the agitator drive motor. The abutment rotates synchronously with the roller ring. The balls periodically contact the surface of the rubber ball cap and create compression. When the balls pass over the rubber ball cap, local pressure is generated, causing the concrete foaming agent inside the rubber ball cap to be squeezed out through the drainage hole and dripped into the mixing tank, thereby achieving continuous, quantitative, and multi-point injection of foaming agent. The fixed ring tank remains relatively stationary with the mixing tank, while the liquid distribution ring rotates with the mixing tank or agitator. The inner cavities between the fixed ring tank and the liquid distribution ring are connected, ensuring a continuous supply of foaming agent.

[0021] During the rotation of the mixing drum, the corrugated ring fitted onto the surface of the mixing drum rotates synchronously, while the liquid tank on the surface of the fixed ring groove remains stationary. Under the alternating guidance of the corrugated ring's crests and troughs, the end of the elastic push rod elastically extends and retracts, causing the diaphragm to periodically change elastically, thus achieving a negative pressure change inside the liquid tank. This allows concrete foaming agent to be introduced through the liquid delivery pipe and replenished unidirectionally into the fixed ring groove. The period length of the corrugated ring's crests and troughs can be adapted to the working cycle of the pusher wheel, thereby quickly replenishing the internal concrete foaming agent as the hydraulic pressure inside the fixed ring groove and the liquid distribution ring decreases, maintaining a constant pressure effect inside the fixed ring groove and the liquid distribution ring.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0023] 1. It can perform staged mixing, flexibly protect the foam structure, realize quantitative multi-point injection of foaming agent, and has intelligent monitoring and protection functions, so as to fundamentally improve its mixing quality and system operation stability;

[0024] 2. By designing the mixing tank as a rotatable structure and using independently controllable mixing paddles, separate slurry mixing stage and foam mixing stage are set up, which effectively avoids foam from participating in the violent mixing process and significantly improves the integrity of the foam structure and the consistency of concrete molding.

[0025] 3. Flexible mixing blades are installed on the surface of the mixing paddle, which can reduce the impact of foam while maintaining the flow of materials, reduce the phenomenon of foam breaking caused by high shear rate, and improve the foam retention rate and finished product stability of foamed concrete.

[0026] 4. By using a ball-operated compression cap method combined with the dynamic liquid storage structure in the liquid distribution ring, the foaming agent can be continuously, quantitatively, and injected into the stirring zone at multiple points, solving the problem of "localized foam concentration" or foam collapse that is easily formed by traditional centralized spraying.

[0027] 5. The harmonic liquid supply component drives the elastic push rod and diaphragm inside the liquid tank through the periodic motion of the wave ring, forming a stable negative pressure suction and positive pressure pushing process, thereby realizing the continuous supply and directional transmission of concrete foaming agent. This structure requires no additional power drive, relying on the rotation linkage of the mixing tank to complete the liquid supply cycle control. It has the characteristics of fast response, energy efficiency, and balanced flow, effectively ensuring the constant pressure supply of foaming agent in the liquid distribution component, and significantly improving the stability and mixing uniformity of foam injection.

[0028] 6. By collecting parameters such as foam flow rate, stirring torque, tank temperature and liquid level in real time and transmitting them to the PLC feedback control module, the stirring intensity and foam injection rate can be automatically adjusted, and automatic shutdown and stirring lock can be implemented in abnormal conditions to ensure equipment safety and product quality. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the mixing tank of the present invention;

[0031] Figure 3 This is a schematic diagram of the internal structure of the mixing tank of the present invention;

[0032] Figure 4 This is a schematic diagram of the connection of the stirring paddle of the present invention;

[0033] Figure 5 For the present invention Figure 4 A magnified view of a section at point A in the middle;

[0034] Figure 6 This is a schematic diagram of the liquid distribution assembly of the present invention;

[0035] Figure 7This is a schematic diagram of the connection of the rubber ball cap of the present invention;

[0036] Figure 8 This is a schematic diagram showing the connection between the liquid distribution assembly and the harmonic liquid supply assembly of the present invention.

[0037] Figure 9 This is a schematic diagram of the structure of the harmonic liquid supply component of the present invention;

[0038] Figure 10 This is a cross-sectional view of the liquid tank section of the present invention.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Base frame; 2. Mixing tank; 3. Liquid distribution assembly; 4. Harmonic liquid supply assembly; 5. Monitoring system; 6. Feed hopper; 7. Discharge hopper; 11. Bearing frame; 12. Roller drive motor; 21. Mixing blade; 22. Mixing paddle; 23. Mixing drive motor; 24. Roller ring; 25. Push roller; 26. Ball bearing; 27. Mixing paddle blade; 28. Mixing paddle shaft; 31. Fixed ring groove; 32. Liquid distribution ring; 33. Rubber ball cap; 34. Liquid guiding septum; 35. Drain hole; 41. Wave ring; 42. Liquid tank; 43. Elastic push rod; 44. Diaphragm; 45. Liquid delivery end pipe; 46. Liquid inlet end pipe. Detailed Implementation

[0041] like Figures 1-2 The foamed concrete mixing device base frame 1, which has a protective mechanism, is an integral support structure. Its surface is equipped with a bearing frame 11 to support the mixing drum 2 and enable its rotational movement. Feed hoppers 6 and discharge hoppers 7 are installed on both sides of the base frame 1 for feeding raw materials and discharging materials after mixing.

[0042] like Figures 3-5The mixing tank 2 has a spindle-shaped cylindrical structure and can rotate during contact with the bearing frame 11, making it suitable for tumbling mixing of slurry. A rolling drive motor 12 is mounted on the base frame 1 to drive the bearing frame 11 to rotate, achieving rotation of the mixing tank 2 through contact between the bearing frame 11 and the surface of the mixing tank 2. Several stirring blades 21 are provided inside the mixing tank 2, divided into two groups and symmetrically distributed on both sides of the stirring paddle 22, used to push and tumble the material during rolling. A rotatably mounted stirring paddle shaft 28 is located in the center of the inner side of the mixing tank 2, used for low-speed stirring of the slurry during the foam mixing stage. The stirring paddle shaft 28 is driven to rotate independently by the stirring drive motor 23. A roller ring 24 is fixedly mounted on the outer surface of the stirring paddle 22, and several spiral blade-shaped stirring blades 27 are provided on the roller ring 24. The stirring blades 27 are made of flexible material and can exert low-shear pushing on the foamed concrete during stirring, reducing the risk of foam breakage. Multiple abutment members 25 are fixedly connected to the outside of the roller ring 24. Each abutment member 25 has a ball bearing 26 sleeved on its surface. The ball bearing 26 slides in contact with the outer surface of the liquid distribution ring 32 in the liquid distribution assembly 3.

[0043] Rolling contact extrusion process: During the foam mixing stage, the rotating agitator 22 drives the roller ring 24 on its surface to move together with the abutment 25. The ball bearings 26 sleeved on the surface of the abutment 25 continuously slide against the surface of the liquid distribution ring 32. When the ball bearings 26 pass above the rubber ball cap 33, local pressure is generated, completing the periodic dripping of the foaming agent.

[0044] like Figures 6-7 The liquid distribution assembly 3 includes: a fixed ring groove 31 fixed to the surface of the base frame 1, a liquid distribution ring 32 fixed to the inside of the mixing tank 2, and multiple rubber ball caps 33 fixed to the surface of the liquid distribution ring 32. The liquid distribution ring 32 rotates or remains stationary with the tank body. The fixed ring groove 31 is externally connected to the harmonic liquid supply assembly 4. The foaming agent enters the inner cavity of the liquid distribution ring 32 through the inner cavity of the fixed ring groove 31. The fixed ring groove 31 and the liquid distribution ring 32 are connected by a sliding fit to maintain a sealed communication state. Each rubber ball cap 33 is a hemispherical rubber cover with a hemispherical cavity inside and a drain hole 35 at the bottom. It stores liquid inside when not under pressure. The surface of the liquid distribution ring 32 is provided with several liquid guiding septa 34 to realize the unidirectional introduction of concrete foaming agent from the liquid distribution ring 32 to the inner cavity of the rubber ball cap 33.

[0045] The injection control mechanism of the rubber ball cap 33 is as follows: When its upper surface is pressed by the ball 26, it deforms and generates positive pressure, which forces the foaming agent in the drain hole 35 to be squeezed out; when the ball 26 is removed, the rubber ball cap 33 recovers due to the material rebound and re-absorbs the foaming agent in the liquid distribution ring 32, realizing the "pressure-absorption-pressure" cycle.

[0046] During the foam mixing stage, the agitator 22 rotates independently at low speed under the action of the agitator drive motor 23, and the abutment 25 rotates synchronously with the roller ring 24. The balls 26 periodically contact the surface of the rubber ball cap 33 and form a compression, so that the concrete foaming agent inside the rubber ball cap 33 is squeezed out through the drain hole 35 and dripped into the mixing tank 2, thereby realizing continuous, quantitative, and multi-point injection of foaming agent. The fixed ring groove 31 remains relatively stationary with the mixing tank 2, and the liquid distribution ring 32 rotates with the mixing tank 2 or the agitator 22. The inner cavities between the fixed ring groove 31 and the liquid distribution ring 32 are connected to ensure a continuous supply of foaming agent. The liquid distribution assembly 3 is mainly used to inject concrete foaming agent into the mixing tank 2 in a controlled, uniform, and continuous manner, realizing multi-point, isobaric, and slow-release dripping of foam.

[0047] like Figures 8-10 The harmonic liquid supply assembly 4 includes a wave ring 41, a liquid tank 42, and elastic push rods 43 fixed to the upper end of the liquid tank 42 and a diaphragm 44 fixed to the lower end of the liquid tank 42. The wave ring 41 is fixedly sleeved on the surface of the mixing tank 2, and the surface of the wave ring 41 has several alternating wave crests and troughs. The bottom end of the elastic push rod 43 is fixedly connected to the surface of the liquid tank 42. The surface of the wave ring 41 slides against the bottom end of the elastic push rod 43. The liquid tank 42 is fixed to the surface of the fixed ring groove 31. The surface of the liquid tank 42 is provided with a liquid delivery pipe 45 communicating with the surfaces of the two fixed ring grooves 31. The surface of the liquid tank 42 is provided with an inlet pipe 46 for the entry of concrete foaming agent. Both the liquid delivery pipe 45 and the inlet pipe 46 are one-way valve structures for the one-way flow of concrete foaming agent. The diaphragm 44 is a rubber component.

[0048] During the rotation of the mixing tank 2, the wave ring 41 fitted onto the surface of the mixing tank 2 rotates synchronously, while the liquid tank 42 on the surface of the fixed ring groove 31 remains stationary. Under the alternating guidance of the crests and troughs of the wave ring 41, the end of the elastic push rod 43 elastically extends and retracts, pulling the diaphragm 44 to periodically change elastically, thereby achieving a negative pressure change inside the liquid tank 42. Concrete foaming agent is then introduced through the liquid delivery pipe 45 and unidirectionally replenished into the fixed ring groove 31. The periodic length of the crests and troughs of the wave ring 41 can be adapted to the working cycle of the abutment component 25, thus rapidly replenishing the internal concrete foaming agent during the hydraulic pressure reduction inside the fixed ring groove 31 and the liquid distribution ring 32, maintaining a constant pressure effect inside the fixed ring groove 31 and the liquid distribution ring 32.

[0049] The monitoring system 5 includes a data acquisition module, specifically comprising a foam flow sensor, a stirring torque sensor, a thermocouple temperature sensor, and a float-type or capacitive level sensor, which are respectively installed on the outer wall of the stirring tank 2 or the inner side of the fixed ring tank 31, forming a multi-dimensional sensing system. The data acquisition module and display module of the monitoring system 5 are used to graphically display the acquired data, such as foam injection rate, stirring load, tank temperature, and liquid level, on the control interface of the display module for operator monitoring and judgment.

[0050] The monitoring system 5 also includes a feedback control module, comprising a PLC main control unit, a motor frequency converter, and an electromagnetic proportional valve control circuit. When the system detects a sudden drop in foam flow, abnormal mixing load, or excessive temperature, it can automatically adjust the speed of the mixing paddle 22 and the foam injection speed. In cases of severe abnormalities, it can trigger a linkage protection mechanism that includes motor shutdown and mixing paddle shaft 28 locking, ensuring safe equipment operation and preventing foam damage and material waste. Through independently controllable rolling mixing and low-speed paddle mixing combined with a liquid distribution mechanism, the system achieves efficient, phased mixing of slurry and foam. Combined with flexible blades, a multi-point injection structure using extrusion, and an intelligent closed-loop control system, it significantly improves the quality stability of foamed concrete and the safety of equipment operation.

[0051] The working principle and usage process of the foamed concrete mixing device in this embodiment are as follows:

[0052] Slurry mixing stage: The mixing tank 2 is supported by the bearing frame 11 on the base frame 1 and rotates, and the slurry mixing stage is completed in conjunction with the rotation drive motor 12. The stirring blades 21 on the inner wall of the mixing tank 2 tumble and mix the initial raw materials during the rolling process. At the same time, the stirring paddle 22 can rotate synchronously or independently. Its spiral blade-shaped flexible stirring paddle 27 and the roller ring 24 form a multi-stage flow guiding structure to assist in the homogenization of mixing.

[0053] Foam mixing stage: In this stage, only the stirring drive motor 23 drives the stirring paddle 22 to rotate at a low speed, and the ball bearings 26 on the surface of the abutment component 25 slide in contact with the surface of the liquid distribution ring 32. As the rotation proceeds, the ball bearings 26 periodically press the rubber ball cap 33, causing the concrete foaming agent inside to be quantitatively squeezed out through the drain hole 35, and introduced into the mixing tank 2 in one direction with the help of the flexible liquid guiding partition 34, so as to achieve multi-point uniform foam injection.

[0054] Meanwhile, the built-in monitoring system 5 collects real-time data on foam flow rate, stirring load, tank temperature, and liquid level changes, and displays the data curves through a human-machine interface. If the system detects a sudden drop in flow rate, an increase in torque, or an abnormal temperature, the PLC main control unit will automatically trigger feedback control to adjust the stirring speed and foam injection rate. If necessary, it will automatically stop the machine and lock the stirring shaft to ensure that the foam structure is not damaged, effectively preventing product scrap or system failure.

[0055] Foaming agent delivery path formation: Concrete foaming agent is fed into the fixed ring trough 31 through an external supply pipe. The fixed ring trough 31 is fixed on the base frame 1 and remains relatively stationary with respect to the rotating mixing tank 2. The fixed ring trough 31 is connected to the liquid distribution ring 32 by a sliding seal, allowing the liquid inside to flow into the inner cavity of the liquid distribution ring 32.

Claims

1. A foamed concrete mixing device with a protection mechanism, characterized in that: The system includes a base frame (1), a mixing tank (2), a liquid distribution assembly (3), a harmonic liquid supply assembly (4), and a monitoring system (5). The mixing tank (2) is rotatably connected to the base frame (1). The mixing tank (2) is equipped with the monitoring system (5), a feeding hopper (6), and a discharge hopper (7). The mixing tank (2) is equipped with a stirring blade (21) and an independently rotating stirring paddle (22). The stirring paddle (22) is connected to a stirring paddle shaft (28), which is driven by a stirring drive motor (23). The stirring paddle (22) is circumferentially equipped with rollers. The roller ring (24) has several abutment parts (25) on its surface, and the abutment parts (25) are rotatably connected to the balls (26); the liquid distribution assembly (3) includes a fixed ring groove (31), a liquid distribution ring (32) and a rubber ball cap (33). The fixed ring groove (31) is slidably connected to the liquid distribution ring (32). The fixed ring groove (31) is set on the surface of the base frame (1) and connected to the harmonic liquid supply assembly (4). The liquid distribution ring (32) has several rubber ball caps (33) on its surface, and the balls (26) slide against the surface of the liquid distribution ring (32). The harmonic liquid supply assembly (4) includes a wave ring (41), a liquid tank (42), an elastic push rod (43), and a diaphragm (44). The wave ring (41) is fixedly sleeved on the surface of the stirring tank (2). The upper and lower ends of the liquid tank (42) are respectively provided with an elastic push rod (43) and a diaphragm (44). The liquid tank (42) is fixed on the surface of the fixed ring groove (31). The surface of the wave ring (41) is alternately arranged with wave crests and wave troughs; The liquid tank (42) is connected to the fixed ring groove (31) through the liquid delivery end pipe (45). The liquid tank (42) is provided with an inlet end pipe (46) for the concrete foaming agent to enter. Both the liquid delivery end pipe (45) and the inlet end pipe (46) are provided with one-way valves.

2. The foamed concrete mixing device with a protection mechanism according to claim 1, characterized in that: The surface of the liquid distribution ring (32) is provided with a plurality of liquid guiding septa (34) for unidirectionally introducing concrete foaming agent from the liquid distribution ring (32) into the inner cavity of the rubber ball cap (33).

3. A foamed concrete mixing device with a protection mechanism according to claim 1, characterized in that: The stirring blades (21) are symmetrically distributed on both sides of the stirring paddle (22).

4. A foamed concrete mixing device with a protection mechanism according to claim 1, characterized in that: The roller ring (24) is provided with several spiral blade-shaped stirring blades (27), which are made of flexible material.

5. A foamed concrete mixing device with a protection mechanism according to claim 1, characterized in that: The rubber ball cap (33) is a hemispherical rubber cover with a hemispherical cavity inside. The rubber ball cap (33) is provided with a drain hole (35).

6. A foamed concrete mixing device with a protection mechanism according to claim 1, characterized in that: The base frame (1) is provided with a bearing frame (11) on its surface. A rolling drive motor (12) is provided on the base frame (1) to drive the bearing frame (11) to rotate. The rotation of the mixing tank (2) is achieved by the bearing frame (11) contacting the surface of the mixing tank (2).

7. A foamed concrete mixing device with a protection mechanism according to claim 1, characterized in that: The monitoring system (5) includes a data acquisition module, a display module and a feedback control module; the data acquisition module transmits real-time monitoring data to the feedback control module; the display module is used to graphically display the foam injection flow rate, mixing load, cylinder temperature and liquid level change curves; the feedback control module is used to automatically adjust the rotation speed of the mixing paddle (22) and the injection speed of the concrete foaming agent according to the real-time monitoring data, and to trigger automatic shutdown protection or mixing shaft lock when the foam flow rate drops suddenly or the mixing load is abnormal.

Images