Spiral feeder

Spiral feeder, also known as spiral feeder, is a new generation product that integrates stable flow conveying, weighing and quantitative control of powder materials; Spiral conveyor, scraper conveyor, and bucket conveyor are equivalent to conveying equipment.

1、 Introduction: Spiral feeder, also known as spiral feeder, is a new generation product that integrates stable flow conveying, weighing and quantitative control of powder materials; Spiral conveyor, scraper conveyor, and bucket conveyor are equivalent to conveying equipment. It has the characteristics of high conveying efficiency, safe and reliable operation, simple structure, complete functions, good sealing, low noise, and beautiful appearance. Suitable for continuous measurement and batching of powder materials in various industrial production environments; Adopting multiple advanced technologies, it operates reliably and has high control accuracy; Especially suitable for continuous measurement and batching of powder materials in industries such as building materials, metallurgy, power, and chemical engineering.
2、 Working principle of spiral feeder
The spiral feeder detects the weight of the material passing through the weighing bridge to determine the weight of the material on the tape. The digital speed sensor installed at the tail continuously measures the operating speed of the feeder. The pulse output of the speed sensor is proportional to the speed of the feeder. The speed signal and weight signal are sent together to the feeder controller, and the microprocessor in the controller processes them to generate and display the cumulative/instantaneous flow rate. The flow rate is compared with the set flow rate, and the control instrument outputs a signal to control the frequency converter to change the driving speed of the feeder, so that the material flow rate on the feeder changes, approaches and maintains the set feeding flow rate, thereby achieving the requirement of quantitative feeding.
3、 Spiral feeder calculation formula
Q——Spiral feeder production capacity, t/h；
D——Spiral feeder blade diameter, m；
d——The diameter of the rotating shaft of the spiral feeder, m；
S——Pitch, m；
n——The rotational speed of the spiral feeder, r/min；
φ——Material filling factor;
ρ——Material bulk density, t/m；
C——Spiral feeder inclination coefficient.
4、 Use and maintenance of spiral feeder
a、 When the feeder is used for batching and quantitative feeding, in order to ensure uniform and stable feeding and prevent material self flow, it should be installed horizontally. If continuous feeding of general materials is carried out, it can be installed with a downward tilt of 10 °. For viscous materials and materials with high moisture content, they can be installed with a downward tilt of 15 degrees.
b、 The installed feeder should have a 20mm clearance for movement, and should be horizontal horizontally. The suspension device should be connected flexibly.
c、 Before the air test, all bolts should be tightened once, especially the foundation bolts of vibration electromagnetic. After running continuously for 3-5 hours, they should be re tightened once.
d、 During the test drive, both vibration motors must rotate in the opposite direction.
e、 During the feeding process, the stability of amplitude, current, and noise should be regularly checked, and any abnormalities should be promptly stopped and dealt with.
f、 Lubricating oil should be added to electromagnetic bearings every 2 months, and lubricating oil should be added once a month during high temperature seasons.
5、 Structural characteristics of spiral feeder
The drive end bearing and tail bearing of the spiral feeder are placed outside the hopper shell to reduce the impact of dust on the bearings and improve the service life of the key components of the spiral feeder mechanism. The middle suspension bearing of the spiral feeder adopts sliding bearings and is equipped with dust-proof sealing devices. The sealing element of the spiral feeder is made of nylon or plastic, which has good sealing performance, strong wear resistance, low resistance, and long service life. The sliding bearings of the spiral feeder have powder metallurgy, nylon, and Babbitt alloy bearings, which can be selected according to different needs. The flexible arrangement of the inlet and outlet of the spiral feeder makes it more adaptable and has been recognized by users.
Spiral feeders are usually composed of several parts, including a drive device, a head section, a middle section, a tail section, head and tail bearings, and an inlet and outlet device. If conditions permit, the drive device can be placed at the discharge end. It is more reasonable to install the drive device and discharge port at the head section (with a thrust bearing assembly), which can keep the spiral in a tensioned state. There are several different lengths of each part, including the head section, middle section, and tail section. The arrangement sequence of each spiral section of the spiral conveyor follows the principle of arranging them in order of their length and arranging spiral sections of the same specification together. Installation starts from the head and proceeds in sequence. Attention should also be paid to the overall layout of the spiral feeder, and the base and discharge port should not be arranged at the flange of the casing joint, and the feed port should not be arranged above the suspension bearing.
6、 Working principle of spiral feeder
The material weight signal from the measuring screw is transmitted to the 3U403 (one machine, one DCS interface) or 3U600 (one machine, sixteen channels) measurement and control system (both 3U403 and 3U600 have microprocessors as the core). By continuously comparing the set value with the actual weight of the material conveyed by the spiral, the speed of the steady flow spiral operation is constantly adjusted. Therefore, the material flow rate can always remain stable at the set value.
7、 Main features of spiral feeder
1. Specially designed for measuring and controlling powdered materials.
2. The feeding spiral has a unique stable flow structure, and the powder evenly sinks across the entire feeding port section, making it less prone to arching and material flushing.
3. The cycloidal pinwheel reduction motor ensures long-term stable operation.
4. The steady flow spiral adopts a variable pitch structure and an outlet overflow method, effectively solving the problem of material flushing (double tube steady flow is used for production>60T/H).
5. The measuring spiral scale adopts a direct weighing structure with three high-precision sensors (tension), which successfully solves the error caused by lever weighing and greatly improves the measuring accuracy.
6. Adopting a digital acquisition module with an effective resolution of up to 1 million; Collection rate of 50 times per second; Annual drift less than 50PPM; The temperature drift is less than 50PPM.
7. Sealed structure to reduce dust emissions.
8、 Performance of spiral feeder:
The spiral feeder has the characteristics of high conveying efficiency, safe and reliable operation, simple structure, complete functions, good sealing, low noise, and beautiful appearance. The spiral feeder adopts advanced transmission technologies such as shaft mounted reducers and hydraulic couplings. The head wheel is covered with rubber, and the bucket is formed by one-time stamping or high-strength plastic bucket. The barrel is connected by a four edge biting process. The spiral feeder is also equipped with explosion-proof motors, belt anti deviation, speed loss switches, and anti reverse devices.
Spiral feeders are widely used in various industrial sectors, such as building materials, power, chemical, metallurgical, coal, aluminum magnesium, machinery, light industry, grain and food industries; Suitable for conveying powdery, granular, and small block materials such as cement, coal powder, grain, fertilizer, ash, sand, etc. at a horizontal or less than 20 ° inclination angle, with material temperature below 200 ℃.
Spiral feeders should not transport materials that are prone to deterioration, high viscosity, or clumping, as these materials will adhere to the screw during transportation and rotate without moving forward or form material blockages at the suspension bearings, which will prevent the spiral feeder from working properly.
The diameter of the spiral feeder ranges from 200 millimeters to 500 millimeters, with a total of five specifications, and the length ranges from 4 meters to 70 meters, with one step every 0.5 meters. When selecting, the standard nominal length should be met, and special requirements can be separately stated in the optional section.
9、 Technical specifications of spiral feeder
1. Measurement accuracy: ≤± 1%
2. Control accuracy: ≤± 2%
3. Speed range: 10:1
4. Working mode: continuous
10、 Spiral feeder: Structural characteristics of spiral feeder
1. The connection between the spiral shaft and the suspension bearing, as well as the head and tail shafts, adopts an embedded tongue type, which does not require axial movement for installation and disassembly, making maintenance convenient. The core shaft is long, there are few hanging parts, and there are few fault points
2. Adopting a variable diameter structure, increasing the volume of the suspension bearing, avoiding contact between the suspension bearing and the material, the service life of the suspension bearing can reach more than two years.
3. Each transmission part adopts a floating connection method, and the suspension bearing is a universal joint structure, which forms a whole rotating floating body with the spiral body, suspension bearing, and tail assembly. Within a certain range, it can rotate freely with the conveying resistance to avoid material jamming or blockage.
4. The head and tail bearing seats are both located outside the shell, and all bearings adopt multi-layer sealing and cooperative sealing technology, resulting in a long service life of the bearings.
5. Compared with other conveying equipment, the spiral feeder has the advantages of small overall cross-sectional size, good sealing performance, stable and reliable operation, the ability to load and unload materials at multiple points in the middle, safe operation, and easy maintenance.
11、 Classification of Spiral Feeders
From the appearance, it can be divided into two series: single tube spiral feeder and U-shaped LS spiral feeder. The single tube spiral feeder adopts a closed conveying material with good sealing performance, which can avoid dust pollution to the environment, improve working conditions, have stable feeding characteristics, can achieve gas locking, and can also eliminate material backflow. The single tube spiral feeder can also be designed for horizontal conveying, inclined conveying, and vertical conveying according to usage requirements, which can reduce equipment manufacturing costs.
According to the driving mode of the spiral feeder, it can be divided into two types:
1. When the length of the screw machine is less than 35m, it is driven by a single end.
2. Manufacturing method - When the screw machine is greater than 35m, it is driven by both ends.