I. Background of the Plan
During the production process of food processing plants, pollutants such as dust and microorganisms (like bacteria and mold) in the air can easily cause food contamination. This affects product quality and safety. As the core equipment for controlling air quality in the workshop, the filters that come with air handling equipment are vitally important. The non-woven high-efficiency filter (HEPA) is ideal for air treatment equipment in food processing plants. It has several advantages: high filtration efficiency, compact structure, and low resistance.
Ii. Key Points for Selecting High-Efficiency Filters Without Separators
During the production process of food processing plants, pollutants such as dust and microorganisms (like bacteria and mold) in the air can easily cause food contamination. This affects product quality and safety. As the core equipment for controlling air quality in the workshop, the filters that come with air handling equipment are vitally important. The non-woven high-efficiency filter (HEPA) is ideal for air treatment equipment in food processing plants. It has several advantages: high filtration efficiency, compact structure, and low resistance.
Ii. Key Points for Selecting High-Efficiency Filters Without Separators
(1) Filtration efficiency
Select the appropriate filtration efficiency based on the cleanliness level requirements of the food processing plant. For general food processing workshops, such as pastry and biscuit processing, use high-efficiency filters without separators rated H13. For workshops with high cleanliness requirements, such as dairy products and aseptic filling, use filters without separators with H14 or U15 efficiency. This ensures effective filtration of tiny particles and microorganisms in the air.
(2) Air volume matching
The rated air volume of the filter needs to match the air volume of the air handling equipment. When selecting the type, it is necessary to ensure that the filter operates at the rated air volume to avoid a decrease in filtration efficiency and an increase in resistance due to excessive air volume, or a waste of air handling equipment capacity due to insufficient air volume. For instance, if the air volume of the air handling equipment is 5000m³/h, a non-woven high-efficiency filter with a rated air volume of no less than 5000m³/h should be selected.
(3) Temperature resistance and moisture resistance
Consider the temperature and humidity of the production environment in the food processing plant. Some food processing techniques (such as baking and steaming) generate relatively high temperatures and humidity. Therefore, it is necessary to select high-efficiency filters without separators that have good heat and moisture resistance. Generally, the temperature resistance range of common high-efficiency filters without separators is -10 ℃ to 60℃, and the humidity resistance range is relative humidity ≤80%. If the temperature and humidity in the workshop environment are relatively high, a dedicated high-efficiency filter without separators with a temperature resistance of ≥80℃ and a moisture resistance of ≥95% should be selected.
(4) Material safety
The filter material, frame and sealing material of the filter must comply with relevant safety standards in the food industry, such as the requirements of FDA (Food and Drug Administration of the United States) certification. The filter material should be made of non-toxic, odorless materials that do not release harmful substances. The frame can be made of aluminum alloy or stainless steel (stainless steel is more suitable for humid and corrosive environments). The sealing rubber strip should be made of food-grade silicone rubber to avoid contamination of food.
Iii. Installation and Sealing Requirements
(1) Preparations before installation
Check whether the filter installation frame of the air handling equipment is flat, clean, free of protrusions, depressions and debris, and ensure that the installation position of the filter meets the design requirements.
Conduct a visual inspection of the high-efficiency filter without separators to check if the filter material is damaged or wrinkled, if the frame is deformed, and if the sealing rubber strips are intact. If any problems are found, they should be replaced in a timely manner.
Clean the installation area, remove dust and debris, and prevent pollutants from entering the interior of the air handling equipment during the installation process.
(II) Installation and Operation
Follow the installation sequence of “from top to bottom and from left to right”, and slowly place the non-woven high-efficiency filter into the installation frame to ensure that the filter adheres tightly to the frame without any deviation.
For the installation method that adopts liquid tank sealing, special sealing fluid (such as food-grade silicone sealing fluid) should be injected into the liquid tank. The injection volume should be such that the sealing fluid covers the sealing edge of the filter by 2 to 3mm, ensuring that there are no bubbles or leakage in the sealing fluid. For the installation method that uses rubber strip sealing, it is necessary to ensure that the sealing rubber strip is in close contact with the frame and the filter without any gap.
After installation is completed, gently press around the filter with your hand to check if there is any looseness and ensure that the filter is firmly installed.
(3) Sealing inspection
After installation is completed, the sealing performance of the filter needs to be tested. The commonly used testing method is the “dust particle counter scanning method”. When conducting the test, place the sampling probe of the dust particle counter close to the sealing area between the filter and the frame as well as the filter itself. If the detected particle concentration exceeds the specified standard (for example, in a cleanliness Class 8 workshop, the concentration of particles ≥0.5μm is ≤ 3,520,000 PC /m³), the installation position needs to be readjusted or the sealing material replaced. Until the seal meets the requirements.
Iv. Maintenance and Replacement Cycle
(1) Daily maintenance
Regularly (it is recommended to do it once a week) check the differential pressure gauge of the air handling equipment and record the initial resistance and operating resistance of the filter. When the operating resistance of the filter reaches twice the initial resistance or exceeds the specified maximum resistance (usually 250Pa to 300Pa), the filter needs to be replaced in a timely manner.
Clean the area around the filter every month to remove dust and debris to prevent the accumulation of debris from affecting the air intake effect of the filter.
If a food processing plant generates a large amount of dust or corrosive gas during the production process, the maintenance frequency should be appropriately increased and the maintenance interval time shortened.
(II) Replacement Cycle
The replacement cycle of the high-efficiency filter without separators is influenced by various factors, such as the cleanliness of the workshop environment, production processes, and the frequency of filter usage. Generally, the replacement cycle is 6 to 12 months. The specific replacement time can be determined based on the following circumstances:
When the operating resistance of the filter reaches the maximum allowable resistance, it must be replaced.
When a food processing plant undergoes major overhauls or upgrades its cleanliness level, it is recommended to replace the filters simultaneously.
If the filter is damaged, leaks or has other problems, it should be replaced immediately.
The rated air volume of the filter needs to match the air volume of the air handling equipment. When selecting the type, it is necessary to ensure that the filter operates at the rated air volume to avoid a decrease in filtration efficiency and an increase in resistance due to excessive air volume, or a waste of air handling equipment capacity due to insufficient air volume. For instance, if the air volume of the air handling equipment is 5000m³/h, a non-woven high-efficiency filter with a rated air volume of no less than 5000m³/h should be selected.
(3) Temperature resistance and moisture resistance
Consider the temperature and humidity of the production environment in the food processing plant. Some food processing techniques (such as baking and steaming) generate relatively high temperatures and humidity. Therefore, it is necessary to select high-efficiency filters without separators that have good heat and moisture resistance. Generally, the temperature resistance range of common high-efficiency filters without separators is -10 ℃ to 60℃, and the humidity resistance range is relative humidity ≤80%. If the temperature and humidity in the workshop environment are relatively high, a dedicated high-efficiency filter without separators with a temperature resistance of ≥80℃ and a moisture resistance of ≥95% should be selected.
(4) Material safety
The filter material, frame and sealing material of the filter must comply with relevant safety standards in the food industry, such as the requirements of FDA (Food and Drug Administration of the United States) certification. The filter material should be made of non-toxic, odorless materials that do not release harmful substances. The frame can be made of aluminum alloy or stainless steel (stainless steel is more suitable for humid and corrosive environments). The sealing rubber strip should be made of food-grade silicone rubber to avoid contamination of food.
Iii. Installation and Sealing Requirements
(1) Preparations before installation
Check whether the filter installation frame of the air handling equipment is flat, clean, free of protrusions, depressions and debris, and ensure that the installation position of the filter meets the design requirements.
Conduct a visual inspection of the high-efficiency filter without separators to check if the filter material is damaged or wrinkled, if the frame is deformed, and if the sealing rubber strips are intact. If any problems are found, they should be replaced in a timely manner.
Clean the installation area, remove dust and debris, and prevent pollutants from entering the interior of the air handling equipment during the installation process.
(II) Installation and Operation
Follow the installation sequence of “from top to bottom and from left to right”, and slowly place the non-woven high-efficiency filter into the installation frame to ensure that the filter adheres tightly to the frame without any deviation.
For the installation method that adopts liquid tank sealing, special sealing fluid (such as food-grade silicone sealing fluid) should be injected into the liquid tank. The injection volume should be such that the sealing fluid covers the sealing edge of the filter by 2 to 3mm, ensuring that there are no bubbles or leakage in the sealing fluid. For the installation method that uses rubber strip sealing, it is necessary to ensure that the sealing rubber strip is in close contact with the frame and the filter without any gap.
After installation is completed, gently press around the filter with your hand to check if there is any looseness and ensure that the filter is firmly installed.
(3) Sealing inspection
After installation is completed, the sealing performance of the filter needs to be tested. The commonly used testing method is the “dust particle counter scanning method”. When conducting the test, place the sampling probe of the dust particle counter close to the sealing area between the filter and the frame as well as the filter itself. If the detected particle concentration exceeds the specified standard (for example, in a cleanliness Class 8 workshop, the concentration of particles ≥0.5μm is ≤ 3,520,000 PC /m³), the installation position needs to be readjusted or the sealing material replaced. Until the seal meets the requirements.
Iv. Maintenance and Replacement Cycle
(1) Daily maintenance
Regularly (it is recommended to do it once a week) check the differential pressure gauge of the air handling equipment and record the initial resistance and operating resistance of the filter. When the operating resistance of the filter reaches twice the initial resistance or exceeds the specified maximum resistance (usually 250Pa to 300Pa), the filter needs to be replaced in a timely manner.
Clean the area around the filter every month to remove dust and debris to prevent the accumulation of debris from affecting the air intake effect of the filter.
If a food processing plant generates a large amount of dust or corrosive gas during the production process, the maintenance frequency should be appropriately increased and the maintenance interval time shortened.
(II) Replacement Cycle
The replacement cycle of the high-efficiency filter without separators is influenced by various factors, such as the cleanliness of the workshop environment, production processes, and the frequency of filter usage. Generally, the replacement cycle is 6 to 12 months. The specific replacement time can be determined based on the following circumstances:
When the operating resistance of the filter reaches the maximum allowable resistance, it must be replaced.
When a food processing plant undergoes major overhauls or upgrades its cleanliness level, it is recommended to replace the filters simultaneously.
If the filter is damaged, leaks or has other problems, it should be replaced immediately.
