(1) The control strategy for back-blowing and dust removal, including frequency and intensity, plays a crucial role in determining the lifespan of bag-type dust collectors. Given the significant fluctuations in the load of power station boilers and the varying qualities of coal, there are substantial variations in flue gas volume and dust concentration. Thus, during the design phase, multiple back-blowing and cleaning modes should be established based on the pressure differential between the upper and lower chambers of the dust collector (the purified gas chamber and the filter chamber). This approach allows the system to adapt dynamically to the changing operating conditions of coal-fired boilers, thereby extending the service life of the dust collector.
(2) Blockages in the ash hopper are a recurring issue. With the dust collector employing a water-flush ash discharge method—where ash falls into the hopper, moves through an electric airlock, and is eventually discharged into a ditch—certain challenges arise. During winter, particularly when the boiler has been recently activated or restarted after prolonged shutdowns, the ash hopper often becomes blocked. Upon analysis, this obstruction stems from condensation within the hopper and poor sealing of the electric airlock. In colder climates, the external temperatures are low, and once the dust collector begins operation, the hot flue gas condenses on the cooler walls of the hopper. This creates a stagnant zone of flue gas that fails to warm up quickly, causing ash to adhere to the hopper walls and resulting in blockages. Simultaneously, the electric airlock’s inadequate sealing allows "water vapor" from the ash tank to be drawn into the hopper, leading to condensation at the ash outlet, further exacerbating the blockage. Other contributing factors include insufficient heating power and improper placement of the ash hopper. To address these issues, the heating system's power and installation must be carefully calculated based on local climate conditions and ash discharge methods. A preheating sequence should be incorporated into the bag filter startup protocol. Additionally, a robust, high-quality sealing airlock should be installed, and the hopper's insulation should be enhanced.
(3) Faults in the back-blowing and dust-cleaning system frequently occur, with common issues including non-functioning back-blowing solenoid valves, water accumulation in compressed air lines, and jammed rotary mechanisms. The primary cause of Solenoid Valve failure lies in the inherent quality issues of the valve itself. Furthermore, the quality of the back-blowing compressed air (including moisture and dust content) and the reliability of the power supply significantly impact the valve's performance. In colder northern regions, low outdoor temperatures lead to water accumulation or freezing in exposed compressed air lines. Hence, during the design process, water drainage points and insulation measures should be included for outdoor pipelines, with additional heat tracing applied in severely cold areas. As part of the rotary mechanism operates in high-temperature flue gas while another section functions at ambient temperatures, the significant temperature differential between these two parts can result in deformation and jamming. Therefore, temperature considerations must be thoroughly addressed in the design phase to ensure smooth operation.
In summary, optimizing control strategies, addressing ash hopper blockages, and improving the reliability of the back-blowing system are essential steps to enhance the efficiency and longevity of bag-type dust collectors. These improvements not only mitigate operational risks but also contribute to cost savings and environmental sustainability in industrial applications.
NINGBO DOTEC produces various pneumatic valves in China for many years.
Options:
1. Pneumatic Solenoid Valve
2. Pneumatic Air Pilot Valve
3. Pneumatic Hand Valve
4. Pneumatic Foot Valve
5. Pneumatic Flow Control Valve
Pneumatic Valve, Pneumatic Solenoid Valve, 5/2 Pneumatic Valve, 3/2 Pneumatic Valve
NINGBO DOTEC AUTOMATION CO., LTD , https://www.ningbodotec.com