The replacement condition of panel filter
1 year periodic testing of clean air flow area, as well as other environmental parameters measured at the same time efficient in the detection.
2 main test wind speed, the final resistance and leakage rate.
3 the air flow of panel filter decreased to 75% of the rated air flow.
4 the final resistance is 2 times the initial resistance.
5 the wind speed is lower than 0.35m 0.35m /s
Relevant answers are as follows:
1 Too many factors affect the life of a Hepa filter (such as the workshop of humidity, dust conditions, air-conditioning system continuous / intermittent operation mode, plant facilities, maintenance, etc.), general development of the replacement cycle is indeed difficult, GMP standards like there is no specific requirements. Determined based on the authentication results suggest, HVAC systems are the key to pharmaceutical production, and then once a year to verify, according to the measured wind speed, high efficiency filter leak detection, etc. to determine whether to replace, no blocking, no leakage, no mold, dust particles, settlement of bacteria (planktonic bacteria) monitor to meet the requirements you need to replace.
2 Hepa filter to drop to 75% of the rated air volume replacement, in theory, you first test cleanliness, cleanliness of the high failure when the scan speed can also be used anemometer test , GMP provides high-speed efficiency is less than 0.35 must be replaced, the general design of clean room air supply is rated air flow of 60% -80%, another parameter is the resistance, and resistance testing is too much trouble to go to the outlet sandwich technology Drill a hole, because the installation does not have installed each HEPA pressure table, so the resistance is greater than the initial resistance test to be replaced two times, if the design with 484 * 484 * 220 of the filter that is designed to be problems, according to the size of your room return air and calculating, maybe 320 * 320 * 220 is enough.
3 Hepa filter replacement condition for clean room: 1) The minimum flow velocity drops. 2) resistance up to 2 times the initial resistance 3) the leak appears and can not be repaired .
4 Article 3 of the answer: whether it is Hepa filter,prefilter or medium filter (panel filter),when put into use, and the system adjusted to meet our requirements (such as valve opening amount, blower air supply back to the air flow and other parameters to determine) we measured and This is a record of the parameters of Hepa filter,prefilter and medium filter, such as wind speed, resistance, and then the next test, we did not change after determining the system before re-testing their speed, resistance, and thus can determine whether to replace the air filter . But in reality, we might not have identified and fixed these parameters (such as mark the opening of each valve size), but failed to see pressure on the adjustable back windshield size, and sometimes even air conditioning valve opening degree, thereby undermining the balance of the entire system. Come back to that Hepa filter, the most practical method of detection is as below:
1 scan speed, efficiency does not determine the block, and the wind speed and achieve the required uniform value;
2, then leak test, no leakage can basically be considered to determine detected qualified.This is currently the more accepted practice. DOP prices are high but so is unlikely to test once every six months, in addition to blocking high-risk. We move the resistance measurement method. That is installed in each high-side pressure head count, or the opening of the test hole. Resistance to change and then to determine the need for replacement.However, automation and monitoring. This is said to be abroad, the current practice. They do so, the effective life of up to 3 years. The efficiency of our domestic life may be less than a year basically. Because in addition to high quality in itself, but also with the methods we use, detection methods, great relationship