Detailed steps for calculating the air volume and pressure of Roots blower pneumatic conveying
The calculation of air volume and pressure of Roots blower in pneumatic conveying involves multiple factors. The following are the detailed calculation steps:
The calculation of air volume and pressure of Roots blower in pneumatic conveying involves multiple factors. The following are the detailed calculation steps:
1、 Detailed steps for air volume calculation
1. Determine the application scenario:
Clarify which specific pneumatic conveying scenario the Roots blower will be used for, such as dust conveying, granular material conveying, etc.
2. Analyze requirements:
Understand key parameters such as conveying capacity, conveying distance, conveying height, material density, pipeline diameter, and pipeline layout (such as the number of bends).
3. Choose formula:
The basic air volume (Q) can usually be calculated using the formula Q=60V × n, where Q is the air volume (m3/min) and V is the volume (m3), which is the volume of gas that needs to be transported per unit time; N is the rotational speed (rpm), which is the rotational speed of the Roots blower.
Another commonly used formula for calculating air volume is: Q (standard)=Q (intake) × (P (intake gas pressure)/(P (intake gas pressure) - S (relative humidity) × P (water vapor saturation pressure)) × T (thermodynamic temperature of the intake gas)/273.
4. Substitute numerical values:
Calculate the basic air volume by substituting the parameters in the actual application scenario into the formula. For example, if the volume of gas to be transported per hour and the speed of the Roots blower are known, the required air volume per minute can be calculated.
5. Consider pipeline resistance:
Calculate the impact of pipeline resistance on air volume based on factors such as pipeline length, diameter, and number of bends. The greater the resistance of the pipeline, the greater the required air volume.
6. Consider air humidity:
In humid environments, air humidity can affect the density and fluidity of gases, thereby affecting air volume. Therefore, the influence of air humidity needs to be considered when calculating air volume.
7. Consider material characteristics:
The specific gravity, particle size, flowability, and other characteristics of materials can also affect the demand for air volume. Larger air volume is required to transport heavier materials.
8. Comprehensive factor adjustment:
Taking into account the above factors, adjust the basic air volume appropriately to meet the actual transportation needs.
2、 Detailed steps for wind pressure calculation
1. Determine the outlet pressure of the fan:
The outlet pressure of the fan is related to the air volume and is generally given in the Roots blower parameter table or obtained through experimental measurements.
2. Calculate wind resistance pressure:
Wind resistance pressure is the air resistance generated by the exhaust of a Roots blower, generally expressed in terms of wind resistance per unit length (Pa/m) or wind speed (m/s). Calculated based on pipeline length and wind resistance coefficient.
3. Calculate pipeline road resistance:
Pipeline road resistance refers to the resistance caused by factors such as friction, bending, and branching of pipelines, and is generally expressed in terms of pressure drop per unit length (Pa/m). Calculated based on parameters such as pipeline layout, material, diameter, etc.
4. Sum up to obtain the total system pressure:
Add the fan outlet pressure, wind resistance pressure, and pipeline road resistance to obtain the total system pressure. Namely: total system pressure (kPa)=fan outlet pressure (kPa)+wind resistance pressure (kPa)+pipeline road resistance (kPa).
5. Consider compensating for pressure:
In the actual pneumatic conveying process, some compensation pressure needs to be added, such as the pressure difference of the unloader and the pressure of the materials in the material box. Make appropriate adjustments based on the actual situation.
6. Precautions
When calculating air volume and pressure, the accuracy and reliability of all parameters should be ensured.
During the calculation process, margin should be considered to ensure the stable operation of the system and to respond to unexpected situations.
For complex application scenarios, it is recommended to directly contact professional Roots blower manufacturers or technicians to provide detailed engineering parameters and requirements, so that they can provide you with accurate air volume calculations and recommendations based on experience and technical knowledge.
By following the above steps, the required air volume and pressure for the Roots blower in pneumatic conveying can be accurately calculated. However, these calculations are based on estimated values from theoretical models and may need to be adjusted and optimized according to actual situations in practical applications.
