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MAPP Plastics Discussion Forum

The MAPP Plastic Industry Discussion Forum allows members to rapidly communicate with each other. Post both questions and answers to questions that other MAPP members have about any industry topic from material and process issues to R&E Tax Credits and other business issues.

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Posted:  07 Aug 2008 13:54
We have Con Air in performing a PM program and the tech has suggested that we need to pull the heat exchangers on the dryers and soak them for 24 hours either between every material change or once a month. Has anyone heard of this or do it currently?
Posted:  07 Aug 2008 21:02
Im guessing that the "heat exchanger" is actually the "after cooler" on your dryer.  Is this a water cooled or air cooled heat exchanger / aftercooler.

Cleaning between material changes and once a month seems excesive.  I pm our dryers once a year.  Our dryers have a water cooled after cooler.  once a year I run a de scaling fluid through them.  We have no problems.

Are they suggesting you do this on all your dryers or are you having trouble with a particular one.  We run one material that will leach alot of plasticizer.  When this material is used, the heat exchanger does seem to foul, but not so much that it casues problems.

What model of dryer are you using?

Posted:  07 Aug 2008 22:29
Yes, they are the water cooled after coolers. Conair is saying that the after cooler needs to be removed and soak them to clean the outside. We do not have any issues with scale build up internally on the after coolers. We have 23 Conair MDC units. They range in size from 15 to 75 pounds per hour thru put.

Posted:  08 Aug 2008 13:32   Last Edited By: Makuta Technics
Do you see any operating issues?  Is the "outside" clogging and not letting air pass through causing overheating?
What does the manual say about maintenance of the heat exchanger?

I found a manual on Conairs website for a MDCW dryer.   It does say that the coils of the after cooler should be cleaned monthly or more often depending on the material dried.  On the air flow drawing for this dryer there is a air filter before the heat exchanger.  Is this being cleaned every material change and at least once a week?  We do run some material that is "dusty" and would casue this filter to clogg very often not allowing air to flow accross the cooler.  We clean our air filters in the dryers every Monday mornning and at every material change.  This frequency has reduced problems related to the operation of our dryers.

My email is if you would like to contact me.

Posted:  11 Aug 2008 17:02
We do yearly PM's also...This seems excessive...and costly.

Thomas Houdeshell
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