What is procedure of new HEPA filter cooking process in tunnel?

Step 1 : Heat upto 800C ,hold for 10 minute and cool down to 300C.

Step 2 : Heat upto1000C , hold for 10 minute and cool down to 800C.

Step 3 : Heat upto 250 0C , hold for 10 minute and cool down to 800C.

Step 4: Heat upto 350 0C , hold for 10 minute and cool down to 800C.

Now filter cooking process is completed. This process is used for new installation of HEPA filter in hot zone of tunnel.

Dear sir
Hmne heating zone m new hepa filter install kiya h uske liye kya criteria h
Kya procedure h instructions h app vo b btaiye sir

Apka b yhi answer h na sir

Mns app b heating zone ki h baat kr rhe ho na
Yha p

yes this procedure for installation new hepa filter in hot zone of depyrogenating tunnel.

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above mentioned procedure

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Thank you Mr. Manoj,

Could you please elaborate why its done and its Rationale.


Binder- A substance used to bond the glass fibers together that gives some structural strength to the media. The binder is a normal part of HEPA filter manufacturing.

During burn off procedure ,There will be smoke, possibly a pungent odor, and a residue on interior surfaces. This is a result of oxidation of the binder, and the evaporation/decomposition of any challenge agents.

Check the oven for particles or the exhaust for smoke and odor to determine that the burn-off is finished. the burn-off should be done at or above the maximum process temperature. The filter should not be cooled faster than 1 degree C per minute. Burn off the filter until the downstream air is clean enough for the process.

The completion of the burn-off period should be based on the particle level in the oven. Laminated media will take longer than the standard HEPA media to burn off to a particular cleanliness level, at the same temperature. Both types of media will burn off faster at higher temperature.

If it is necessary to move the equipment after the burn-off process (which is not recommended),considerable care should be used. The binder which gives strength to new filters is now gone and the media is very fragile. Any handling of either the filter alone or the equipment with the filter installed is strongly discouraged. The media may crack or tear (leak).

For best clean oven processing, it is recommended that the oven be thoroughly cleaned after the burn-off period and at regular intervals thereafter.

The filter hold-down nuts should be checked after burn-off and tightened again, if necessary. For best results, this step should also be repeated on a regular basis. Most oven gaskets are known to take a set, and thus require tightening after heating.

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