Application of Rotary Paddle Switch in Dust Measurement of Dust Collector

Shanxi Yaxin Group is a modern enterprise integrating coal mining, coal preparation, coking, chemical production recovery, gas purification, mechanical and electrical equipment operation. Due to the high-volume dust loads in coal production, a system used to enhance the quality of air released from industrial and commercial processes by collecting dust and other impurities from air or gas is required. Generally, a dust removal system consists of a centrifugal fan, pulse bag filter, frequency converter, instrument system, circulating cooling water system, ash conveying and discharging system, compressed air system and pipe network system.

Pulse bag filter is an important part of the dust removal system in a cooking plant. A pulse jet bag filter also called a pulse jet baghouse or pulse jet dust collector is a self-cleaning dry filtration system. In the process of coking production, dust is inhaled into the main pipe of the dust removal system, the large particle dust is separated in the gravity dust collector and then directly flows into the ash hopper. The smaller dust evenly enters the case in the middle of the bag filter and adsorbs on the outer surface of the filter bag. The dusty gas enters the air purification chamber after being filtered by a filter bag, and is discharged into the atmosphere through the exhaust pipe. When filter bag resistance reaches the limit value of 1500Pa, the dust removal system turns on pulse injection according to the differential pressure program. At this time, a compressed air machine shakes off the dust attached to the surface of the filter bag, then the dust is discharged by the ash removal machine through an ash hopper.

With the increased dust, ashes in ash hoppers accumulate, if not removed in time, can lead to false operation of the whole dust collector. So, to establish a reliable ash removal system, it is necessary to apply a stable, reliable and accurate level switch to ensure the dust position in the ash hopper is accurately detected. However, the original rotary paddle switches purchased by the client are low in reliability, the phenomena of jamming, false signal and false alarm frequently occur, which seriously affects the working effectiveness of the whole dust removal system.

In fact, the reliability of rotary paddle switch is affected by many factors, its motor quality and shaft sealing are also the key components in the aspect of reliability.

According to the working principle of rotary paddle switch, the quality of the micro motor has a crucial impact on the stability and reliability. If the motor is not selected properly (such as the selection of domestic poor quality motor), can lead to frequent failures:

1. The motor coil is easy to burn and scrap;

2. Insufficient motor torque and frequent false alarm;

3. Due to the light weight of motor, the self-fibrillation cannot be eliminated during operation, which affects the stability;

4. Motor speed decelerating device is easy to wear and easy to happen gear seizing, or parts rupture, lead to motor inoperative.

Most of China domestic rotary paddle switches are in low price, to save the capital, most select inferior motor. However, the internal decelerating device of low-quality and low-cost motor mostly uses plastic thin gear, low standard coil, which greatly reduces the performance and reliability of whole product.

Also, the sealing of the rotary paddle switch has a direct impact on reliable operation. If fine dust enters, or penetrates into the gap of the rotating shaft, resulting in accumulation inside the probe rod, which increases the resistance of spindle rotation, affecting normal rotation of the paddle, and finally causing motor unable to drive the spindle to rotate, thus outputting the wrong switch signal.

The reason why the client finally selects Jiwei Spin-11P Rotary Paddle Switch is because of the good reputation of Jiwei brand and its excellent performance after the test trial.

1. Precision mechanical detection structure, imported high-quality micro sensitive deceleration motor and reliable microswitch greatly improves the sensitivity, durability, stability and reliability.
Application of Rotary Paddle Switch in Dust Measurement of Dust Collector

2. Unique oil seal design makes the protection level up to IP65, can prevent oil, dust and viscous mixture from entering into the instrument along the rotating shaft.

3. For Spin-11P Protective Rotary Paddle Switch, 304 / 316L stainless steel is used as protection tube for the main shaft, which effectively avoids impaction of materials, and is suitable for the measurement of high density solid particles.

4. Integrated design and anti – loose mechanical control mechanism, easy for parts replacement and maintenance.

5. The overload protection device of the clutch is designed for the whole machine, effectively preventing the paddle from being damaged by excessive external force. At the same time, the automatic protection device can stop working if the paddle is blocked, which protects the motor and effectively extends its service life. Besides, the whole instrument is not affected by medium shape, specific gravity, adhesion, temperature, dust concentration and so on.

6. With Gas and Dust Explosion-Proof Certificates, applicable in a wide range.

Because of the characteristics of the above-mentioned, Jiwei Spin-11P Rotary Paddle Switch can fully meet the user’s requirements in the harsh working conditions, and especially suitable for stable and reliable dust measurement of dust collector.

At present, 48 sets of Spin-11P Rotary Paddle Switches are in stable operation in the new project, without any false signal output and false alarm. Due to the excellent performance, the client plans to replace all other original instruments to Jiwei Spin-11P Rotary Paddle Switch.