How to configure the FFU filter when there is a lot of dust in the lithium battery workshop?
Direct answer: First find out which process the dust comes from and the path it takes to enter the FFU, and then configure the pre-filter and HEPA or ULPA end filter based on the project's cleanliness requirements. The selection should check the resistance of each level of filter under the design air volume, the air supply capacity under the FFU target air volume, and formulate pressure difference monitoring and replacement methods. Increasing filtration levels cannot replace source control of process dust.
The amount of dust generated in different processes in the lithium battery workshop may be different. If the dust is mainly generated at the equipment operating point, the local capture and exhaust scheme of the process equipment should be evaluated first; NIOSH engineering control information also lists local exhaust as a method to capture airborne emissions near the pollution source. FFU is responsible for the terminal filtered air supply in the clean area. It is not appropriate to hand over a large amount of process dust to the FFU filter for processing.
Pre-filtration: reducing the burden on end filters
In areas with a lot of dust, a pre-filtration configuration that matches the FFU structure and fan performance can be evaluated. The efficiency, size, installation location and replacement method of the pre-filter should be determined based on the air inlet conditions. After adding a pre-filter, the system resistance will also change and must be re-confirmed.The air volume of the FFU machine at the design level.
Pre-filters need to have an executable inspection and replacement plan. If its resistance increases significantly, the terminal air supply may be affected; it cannot be included in the configuration at the time of purchase without monitoring the status after operation.
Terminal filtration: choose HEPA or ULPA according to the cleanliness target
HEPA/ULPA air filters should be selected based on process particle control requirements, filtration efficiency and testing requirements. If the project adoptsFor ULPA filters , the resistance, power consumption and FFU fan operating point under the design air volume must also be checked simultaneously. The higher the filtration level does not automatically mean the better the on-site cleaning effect. The actual air volume and airflow distribution also need to meet the standards.
The sealing of the filter frame and FFU box, on-site maintenance direction and replacement space should also be specified in the technical agreement. Maintenance of high-efficiency filters should be performed according to product instructions and project procedures; pre-filters and terminal filters cannot be regarded as the same cleaning and maintenance objects.
Pressure difference, air volume and cleanliness are monitored together
After installation and commissioning, the initial filter pressure difference, actual air volume and cleanliness at the agreed gear should be recorded as a baseline for subsequent maintenance. During inspection, try to compare data under similar operating conditions. If it is found that the pressure difference increases or the air volume decreases, the pre-filter, terminal filter, seal, control gear and measuring point status should be checked, and then the disposal method shall be determined according to the agreed conditions of the project. Filter replacement should not be based solely on a universal pressure difference value; FFU manufacturer information often takes changes in wind speed or cleaning performance into replacement judgments. FFU filter maintenance information
Aili Industrial's filters, fans, motors, sheet metal and control systems are all produced and developed in-house. The lithium battery project can combine the dust working conditions, pre-filtration configuration, target air volume and maintenance space, match the filter resistance and fan air supply capacity, and confirm the working point of the complete machine through a prototype. Specific filter configuration, monitoring requirements and performance are subject to the project technical agreement and actual test results.
