11 replies to this topic

[Anish]

Hi,

Could you please share your experience of installing exhaust fans in processing area. We are installing big exhaust fans on the top almost near to the sealing in our Juice processing area . We plan to put a wire mesh to avoid the entry of any birds/rodents.

What other precautions to be taken to safeguard the system.

Regards,
anish

[Madam A. D-tor]

What other precautions to be taken to safeguard the system.

Hi Anish,

Why are you screening for birds and rodents but not for insects. Juice will probably attract insects.

Think in advance of cleaning and sanitizing. E.g. can you reach it, how to clean, frequency, etc.

Make sure that air is blown out and that there is no intake of air. I once have seen a incorrectly installed fan, which was taking in air (no filters) in a chicken slaughtery. Microbe load and condensation was a lot lower after they had fixed this.

Make sure it is placed somewehere that it can not contaminate your product. E.g. by dirt or parts falling of.

[Anish]

Thanks Madam D.Tor for your valued points. I will discuss with the concerned.

Regards,
anish

[Dawny P]

I would also consider, in addition to the insect screen, an Electric Fly Killer positioned near the fan so the little blighters would see it straight away when they get in. It's also important not to place it so they can see it from outside and it would encourage them to come in......unless of course you have the extractor fan going 24/7 in which case this is a moot point.

Dawny B.

[MKRMS]

Another topic to consider is how to organise the airflow that results from you air extraction. Naturally, air extraction creates underpressure. Air will enter the building through any opening that is available. How can you prevent excess dust to be drawn into your premises? Is the fabric of the building adequately sealed? Are surrounds paved to reduce the amount of dust that becomes airborne?
In some instances, creating a lobby to reduce dust entering the preparation area is necessary. Also, after installing the exhaust system, air flow should be from clean to dirty areas (e.g. air flow from finished product storage areas to production to raw material storage to avoild contamination of the finished product with contaminatnts that originate from raw materials).

Steps to be taken depend on the situation of your premises.

Best of Luck

Matt

[carine]

Dear Matt,

Can you explain clearly what do u mean by the lobby here ?? In order to maintain the + air flow??

[AS NUR]

Dear Matt,

Can you explain clearly what do u mean by the lobby here ?? In order to maintain the + air flow??

IMO.. you use airlock system, that is a system using small room to separate your premises and the outside place, the room have two door, and if the one door is open the other is closed.. the purpose of the system to reduce contamination from the outside area..
as I know, the open and closed system can be automatically or manually.. and ussually equiped by air shower to eliminate dust..

thats my opinion

rgds

AS NUr

[Simon]

IMO.. you use airlock system, that is a system using small room to separate your premises and the outside place, the room have two door, and if the one door is open the other is closed.. the purpose of the system to reduce contamination from the outside area..
as I know, the open and closed system can be automatically or manually.. and ussually equiped by air shower to eliminate dust..

thats my opinion

rgds

AS NUr

I agree with AS Nur, but in this case I don't think this control is valid as the extractor fans are planned to be in the ceiling. They must be screened to prevent ingress of any pests, dust, debris, water or any potential contaminant. Not easy if the air flow is not to be restricted. Careful design is required and also when in place regular maintenance and cleaning of the extractors.

Regards,
Simon

[KohMengGuan]

Would like to raise some questions regarding exhaust fan though this post is 6 years old.

My concern currently the plant which I work at has negative pressure (low risk food-bread production), some auditors did recommend us to install netting over the exhaust fan (in the event exhaust fans break down, the screen will be able to trap insect) but it just doesn't make sense to me.

My thoughts are that exhaust fan are capable of preventing insect entry, installation of insect netting in the interior would cause dust and insect to be trapped at this netting due to fan drawing air from inside towards outside the facility. No history of birds entry into the fan as we have some grilling on the external.

And in the event that the exhaust fan break down, the negative pressure would cause wind to blow in and blow debris/insect that is on the interior side of the netting(though at the same time, it does prevent entry from the outside the plant). I thought the focus should instead be a system that is able to detect exhaust fan break down.   

[Scampi]

The exhaust fan should be on your facilities preventative maintenance schedule for regular upkeep so mitigate the risk of breakdowns. Do you have a deviation in place should the fan stop working mid production? If there is not a flapper in the duct that will close if the fan stops working, you could potentially have an entire lot of product that needs to be discarded because external contaminates were allowed access to your product

[Tomato Country Girl]

you may also want to contact a company by the name of Permatron they are based in Michigan and design custom covers for fans, I bought 4 to cover our fans we had in processing which were close to product to keep contamination down, they are reasonably priced and mine had a 5 year warranty and were FDA approved materials.   Mind you these fan "bonnets" are for regular industrial type fans for cooling staff while on processing line in summer heat., but this company does a huge amount of different types of air filters.

 

Good Luck

[Charles.C]

Do note that the OP was dated 6 years ago.

 

But thanks anyway.