In the process of using the dry ash transportation pump equipment for fly ash transportation, pipeline blockage will occur due to various reasons. Here, daewoo machinery analyzes the reasons causing the blockage of the pneumatic conveying system of fly ash for your reference:
Causes of blockage of fly ash during pneumatic transport:
1. Air flow rate decreases. When the air velocity decreases, the movement speed of the pulverized coal particles gradually decreases, and then the uneven flow and irregular pulsation are generated, and the pulverized coal particles begin to stagnate at the bottom of the pipe. At this point, the particles near the bottom of the tube slide along the bottom wall sometimes, sometimes stay; Particles near the center of the tube flow faster. If the airflow rate continues to fall, the upper particles begin to settle and become clogged. At this point, the particles suddenly gather in a place of greater resistance, filling the entire flow section and forming a blockage.
2. Coal powder is wet, sticky and poor in permeability, so it is difficult to transport or even difficult to transport.
3. Coal powder is mixed with debris, such as wood, nails and stones, etc.
4. Increase of local resistance. As the curved pipe is ground through and then soldered to form a knot in the inner coil, local resistance increases, resulting in blockage.
5. The air conveying source is unqualified. The air source pressure is low, which cannot overcome the resistance in the whole system, or the air supply is uneven, and the pressure drops suddenly in the middle of the transmission. In addition, high air source humidity will also increase the coal humidity resulting in bonding and blockage.
6. Improper piping arrangement. More horizontal vertical layout, greater resistance than inclined layout. The bending pipe, reversing device and other parts with high resistance are mainly distributed at the end of the pipe, which is prone to blockage.
7. System leakage. Loose sealing of equipment or pipeline interface, and leakage of air in the middle of pipe wear-through, etc., cause the transmission speed to drop and cause blockage.
8. The outlet of the sending device is too small or the outlet resistance is too large, causing blockage at the outlet.
9. The radius of curvature such as reversing device and bending pipe is too small, resulting in too large local resistance and obstruction.
10. Wrong side of pipe joint or rusted rough inner wall, resulting in increased local resistance and obstruction.
11. Improper operation or reverse order.
A measure to prevent blockages
1. In piping layout, the total degree of the pipe and its Angle should be reduced as much as possible according to the shortest transportation distance, and the pipe should be separately arranged in small degrees instead of a large degree.
2. Any device or component that produces local resistance, such as commutation device, bend, etc., shall be as close to the sending device as possible.
3. Reasonable selection and design of transmission device, reversing device and other equipment and components.
4. The equipment or pipeline interfaces should be aligned, tight, with little clearance and no wrong side. The center line of the pipe should be as straight as possible, reduce twists and turns, smooth inner wall, and consider the convenience of disassembly and assembly.
5. Special gas storage tanks and oil and water separator should be set up before the high-pressure air conveying system to guarantee the pressure, flow and quality of the air source.
6. Ensure that coal powder does not contain debris.
7. Reduce the humidity of coal powder to ensure the easy transport of coal powder.
8. The delivery system shall be automatically or semi-automatically controlled to eliminate blockages caused by misoperation.
Understanding and mastering the causes of pipeline blockage and prevention measures in the pneumatic conveying process can improve the efficiency of pneumatic conveying and reduce the occurrence of faults, so that the pneumatic ash ash removal system can be better applied in the thermoelectric industry and bring more benefits to enterprises.