What is the pressure of compressed air in the cement plant
Specification for pressure parameters of compressed air system in cement plants
In the cement production process, compressed air, as a key power source, is widely used in pneumatic actuators, instrument control and process dust removal. In order to clarify the system design standards and ensure stable operation of equipment, the specifications for compressed air pressure parameters in cement plants are now described as follows:
1. Typical gas consumption scenarios and pressure requirements
1. pneumatic actuator
- application scenarios: Pneumatic valves, fluidization silo devices, packaging machine bag insertion mechanisms, etc.
- pressure requirements: 0.4-0.6MPa (4-6kgf/cm²), it is necessary to ensure that the cylinder moves quickly and without jams.
2. instrument control system
- application scenarios: Signal transmission and execution of pressure transmitters, flow meters, material level switches and other instruments.
- pressure requirements: 0.3-0.5MPa (3-5kgf/cm²), the pressure needs to be kept stable, and the fluctuation range is ≤±0.05MPa.
3. Process dust removal system
- application scenarios: Pulsed ash cleaning with bag dust remover, vibrating device for electric precipitator.
- pressure requirements: 0.5-0.7MPa (5-7kgf/cm²), sufficient impact force needs to be provided to ensure that the filter bag is completely cleaned.
4. material conveying system
- application scenarios: Pneumatic conveying pumps, air chutes and other powder conveying equipment.
- pressure requirements: 0.2-0.4MPa (2-4kgf/cm²), the pressure needs to be adjusted according to the conveying distance and material characteristics.
2. Principles for selecting system design pressure
1. Air supply main pressure
- design value: 0.7-0.8MPa (7-8kgf/cm²), and a pressure margin of 10%-20% is reserved to compensate for the pipeline pressure drop.
- basis: Meet the pressure requirements of the most distant gas equipment, while avoiding increased energy consumption caused by long-term high-pressure operation.
2. Tank volume matching
- configuration principle: Gas storage tanks are configured at 15%-20% of the total gas consumption. For example, for a cement production line with a daily output of 5000 tons, it is recommended to configure gas storage tanks of 10-15m³.
- role: Stabilize the air supply pressure and reduce frequent starts and stops of air compressors.
3. Pressure drop control requirements
- pipeline design: The flow rate of the main pipe is ≤8m/s, and the flow rate of the branch pipe is ≤15m/s, ensuring that the pressure drop is ≤0.1MPa/100m.
- valve selection: Priority is given to low-resistance ball valves to reduce local pressure losses.
3. Pressure adjustment plan for special scenarios
1. high altitudes
- adjustment measures: For every 1000 meters increase, the atmospheric pressure drops by about 12%, and the air compressor exhaust pressure needs to be increased by 0.1-0.15MPa.
- companion device: Configure a booster fan or select a high-pressure ratio model to ensure that the end pressure meets the standard.
2. winter operation
- precautions: In low temperature environments, the air density increases, and the air compressor displacement increases by 5%-10%. The exhaust pressure needs to be appropriately reduced to prevent overpressure.
- protective measures: Add electric heat tracing devices to the pipeline to prevent condensation water from freezing and clogging.
4. Operation and maintenance management requirements
- Pressure inspection: Record the pressure of the gas supply main pipe and key gas points every day, and respond within 2 hours when the alarm exceeds the limit.
- leak detection: Use an ultrasonic leak detector to check the pipeline every quarter. Repair the tissue when the leak exceeds 5% of the total gas volume.
- energy efficiency optimization: Through frequency conversion transformation, the air compressor can automatically adjust the pressure according to the air consumption, and the energy saving rate can reach 15%-25%.
V. Supplementary Provisions
This specification applies to the design and operation and maintenance management of compressed air systems in cement production enterprises. When special processes such as waste heat power generation and collaborative disposal are involved, a special pressure control plan needs to be formulated based on the characteristics of the gas consumption.
By clarifying the pressure parameters and design principles of the compressed air system of cement plants, companies can optimize the gas supply plan, improve equipment operation stability, and reduce energy consumption and maintenance costs.