Does the pulp and paper industry require high temperature compressed air?

The pulp and paper industry requires high-temperature compressed air in some processes, but it is not necessary for the whole process, and its use depends on the specific process requirements.. The following is a detailed analysis:

typical application scenarios of 1. high temperature compressed air

1. pulp Molding and Drying
   in the production of molded pulp products (such as disposable tableware, packaging materials), compressed air is often used for molding and drying:
   • molding stage: Press the pulp into the mold by compressed air to form the required shape. At this time, the compressed air needs to have a certain temperature (usually 377~400 ℃) to accelerate the dehydration of pulp and improve production efficiency.
   • Drying stage hot compressed air is used as a drying medium to further reduce the moisture content of the product (from 45% to 8% to 12%). High temperature can shorten the drying time, but the temperature should be controlled to avoid deformation or strength reduction of the product.
2. Hot press shaping and post-processing
   some pulp molded products need to be shaped by hot pressing to improve surface flatness or cushioning performance. At this time, compressed air may be used to transfer heat or assist pressing, and a higher temperature needs to be maintained to meet process requirements.

2. compressed air demand for non-high temperature scenarios

1. pneumatic Control and Power Transmission
   compressed air is the main power source of pneumatic valves, instruments, cylinders and other equipment in paper mills. There are no special temperature requirements for such applications, but the air must be clean (e. g. oil-free, particle-free) to avoid contamination of the product or damage to the equipment.

2. Pulp Pond Agitation and Fiber Separation
   in the pulp preparation stage, compressed air is used to stir the slurry or separate the fibers, usually without high temperature, but the pressure and flow rate need to be controlled to ensure process stability.

3. Vacuum transport adsorption and paper transfer
   in the paper feeding process, vacuum suction technology relies on compressed air to achieve precise paper separation and delivery. Such scenarios do not require temperature, but require stable air pressure and flow control.

Challenges and Solutions for 3. High Temperature Compressed Air

1. energy consumption and cost
   high-temperature compressed air requires additional heating, which significantly increases energy consumption. For example, a household paper enterprise optimized the compressed air system to reduce the average specific power from 7.9 kW/(m & sup3;· min) to 5.6 kW/(m & sup3;· min), saving 5.002 million kWh per year and 3.501 million yuan in cost. This shows that reasonable control of compressed air temperature can significantly reduce operating costs.

2. System Optimization and Waste Heat Recovery

   • heat recovery technology: Recovery of compressed air waste heat through the gas-gas heat exchanger for preheating fresh air or heating process water, which can improve energy efficiency. For example, a company's heat recovery system is 90% efficient, significantly reducing the amount of steam replenishment.
   • intelligent control system: Dynamically adjust the compressed air temperature and pressure according to the gas demand to avoid redundant gas supply and further reduce energy consumption.

3. Equipment selection and maintenance

   • oil-free compressor the paper industry has extremely high requirements for air quality, and oil-free compressors are required to avoid oil pollution.
   • Drying and purification equipment: Equipped with high-efficiency dryers (such as zero gas consumption compression heat dryers) and filters to ensure that the compressed air meets the process requirements and extend the life of the equipment.

4. industry trends and recommendations

1. energy-saving and low-carbon development
   as energy costs rise and environmental pressures increase, paper companies are reducing the energy consumption of compressed air systems through technological upgrades. For example, the use of high-efficiency permanent magnet variable frequency air compressor, intelligent control system and waste heat recovery technology can achieve energy saving rate of more than 20%.

2. Process suitability
   the application of high temperature compressed air needs to be strictly matched to the process requirements. For example, in pulp molding, high temperature may cause deformation of the product, and the best process parameters need to be determined through experiments.

3. Full lifecycle management
   from equipment selection, system design to routine maintenance, energy efficiency, reliability and cost need to be considered. For example, regular detection of compressed air leaks (usually 25% to 30% of air loss) can avoid energy waste and productivity loss.