Technical guide for application of Roots blower in powder conveying
1、 System working principle
The Roots blower serves as a gas source device in the powder conveying system, generating stable airflow to achieve:
1. Positive pressure conveying system: The fan outlet is connected to the conveying pipeline to push the powder forward
2. Negative pressure conveying system: The inlet of the fan is connected to the conveying pipeline to suction the powder material
3. Mixed conveying system: positive and negative pressure combined conveying
2、 Calculation of key design parameters
1. * * Calculation of conveying gas velocity * *:
Suspension velocity: V=√ (4Gd (ρ - ρ)/3 ρ C)
Among them: g=9.81m/s2, d is the particle diameter, ρ is the particle density, ρ is the air density, and C is the drag coefficient
2. * * Pressure loss calculation * *:
ΔP=ΔP+ΔP+ΔP+ΔP
Including: pipeline friction loss, acceleration loss, material lifting loss, accessory loss
3. Calculation of gas-solid ratio:
μ=G/G
Where G is the mass flow rate of powder (kg/h), and G is the mass flow rate of air (kg/h)
3、 Key technical points for professional selection
1. * * Fan specification selection * *:
-Airflow margin: calculated value x 1.1-1.3 coefficient
-Pressure margin: system resistance x 1.15-1.25 coefficient
-Power verification: P=Q × Δ P/(3600 × η)
Take η as 0.65-0.85
2. Wear resistant treatment plan:
|Processing technology | Hardness (C) | Applicable scenarios|
|---|---|---|
|Tungsten carbide spraying | 65-72 | High wear condition|
|Nickel based alloy | 55-62 | Medium wear|
|Nitriding treatment | 50-55 | General working conditions|
3. Sealing system configuration:
-Gas seal: 0.2-0.3MPa clean gas source
-Mechanical seal: Double end container type
-Maze seal: ≥ 5 sealing teeth
4、 System control scheme
1. * * Variable frequency control strategy * *:
-Constant pressure control: maintain stable pipeline pressure
-Constant flow control: ensuring stable conveying volume
-PID parameter setting: proportional band 20-40, integration time 3-5 seconds
2. * * Protection System * *:
-Overvoltage protection: set value=rated pressure × 1.1
-Overload protection: current setting=rated current x 1.2
-Temperature protection: Alarm for bearing temperature ≤ 95 ℃
5、 Installation and commissioning specifications
1. * * Installation Requirements * *:
-Basic levelness ≤ 0.1mm/m
-The support spacing between import and export pipelines is ≤ 8 times the pipe diameter
-The compression amount of the shock absorber is controlled between 10-15mm
2. * * Debugging steps * *:
1. No load test run (1 hour)
2. 30 load operation (2 hours)
3. 50 load operation (4 hours)
4. Full load operation (24 hours)
6、 Energy efficiency optimization measures
1. * * System optimization * *:
-Adopting variable diameter pipeline design
-Optimize bend radius (R/D ≥ 5)
-Set up pressure boosting device (long-distance transportation)
2. * * Run optimization * *:
-Gas-solid ratio control
-Conveyor speed adjustment
-Batch transportation optimization
7、 Common problem solutions
1. * * Powder deposition issue * *:
-Add pipeline vibrator
-Set up blowing device
-Optimize the conveying gas speed
2. Pulse vibration problem:
-Install buffer tank (volume ≥ 5 times instantaneous flow rate)
-Set vibration damping orifice plate
-Adjust the conveying frequency
3. * * Sealing failure issue * *:
-Increase the sealing gas pressure (+0.05MPa)
-Replace the sealing material (such as silicon carbide)
-Improved sealing structure (double labyrinth+gas seal)
8、 Maintenance and upkeep standards
1. * * Daily inspection items * *:
-Vibration value (≤ 4.5mm/s)
-Noise level (≤ 85dB)
-Lubricating oil condition (monthly inspection)
2. * * Regular Maintenance Plan * *:
|Cycle | Maintenance Content|
|---|---|
|500h | Replace lubricating oil|
|2000h | Check the impeller clearance|
|8000h | Replace bearing components|
3. * * Lifespan of key components * *:
-Impeller: 3-5 years (wear-resistant type)
-Bearings: 2-3 years
-Sealing: 1-2 years
Note: In practical applications, parameters need to be adjusted according to specific working conditions. It is recommended to configure an online monitoring system to achieve predictive maintenance. For special powders (such as explosive, high viscosity, etc.), customized solutions are required.
