Dust Collection At Fluid Bed Dryer
Dear Mr. Alvarez,
Dryer air carrying dried products in a humid atmosphere is universally
collected in bag filters without problems. The most important parameter
is the outlet temperature of the dryer compared to the dewpoint of the
humid process air. With fluid beds the air quantity compared to the moisture
content usually means that the dewpoint is far below the filter bag ambient.
Care should be taken if hot air is to partly recirculated to save energy
which can lead to a closer differential between baghouse ambient and
dewpoint.
We, Atritor, like to keep outlet temperatures at least 10C/18F above
dewpoint.
Hope this is of help.
Best regards,
George Milburn
gmilburn@atritor.com ■
Re: Fluid Bed Dryer´S Dust Collection
Hello from Ibis International, Inc.
We cannot help with this application. However, you may consider an automatic roll filter depending on the air volume (m3/Hr). The other possibilityis a wet scrubber.
Good Luck,
Ibis, Inc. USA
sales@ibis-usa.com ■
Re: Fluid Bed Dryer´S Dust Collection
I globally agree to R.Wolbier's answer, but the limit is, to my opinion, more drastic than the dew-point (which is air saturation temp). The limit temperature is such as air relative humidity should be equal (or inferior to) to water activity in the dry product, for example 50% (instead of 100%), which is not a real difficulty. You may use the water sorption isotherms of your product.
For this, it should be sufficient to maintain the air temperature in the filter, which means you may have to heat the filter walls (or at least, to have good insulation), in order to keep air over this limit (which may be far over the dew point).
Besides, if you use pressurized air to clean the filter cyclically by counter current flow, it is a cause of air refreshing, and product moisturizing. So, you must heat this air too, or use another way of cleaning the bag (mechanical shakers, ...).
Good luck. JV
PS : best regards to Dr Wohlbier, who sent the message ■
Re: Fluid Bed Dryer´S Dust Collection
Please direct your contact for fabric filters to Bob Pirrmann at 770
693-2135 or rpirrmann@amerexind.com
For the type of bag fabric, I suggest you contact Mr. Clinton B. Scoble
Jr. with
BWF America, Inc.
7453 Empire Drive #340
Florence, KY 41042
USA
Phone: (859) 282-4550
FAX: (859) 282-4555
They have a collector bag material that may be able to resist the moisture
problem.
Regards,
Jim Boen
Benetech, Inc.
Direct Phone: 770 693-2113
Sales FAX: 770 693-2102
Direct Digital FAX: 770 693-2108
Cell Phone: 770 714-2771
Fabric For Fluid Bed Dryer
Expanded ptfe treated filter media is very successful in handling very high moisture levels in fluid bed dryer applications. We have several installations in the Food Industry with this type of application. The ePTFE also has a greater ability to recover from upset conditions versus other fabric style options. Feel free to contact me for more detailed information:
BHA Group
1-800-821-2222
tstark@bha.com ■
Dust Collection At Fluid Bed Dryer
I suggest you contact Hosokawa Micron (offices in Summit, NJ) - they are
probably the largest manufaturers of bag houses - used to be Micropul, now Hosokawa Micron's Environmental Division
Mr. Warren Fuller
President
Paul O. Abb Inc.
139 Center Ave.
Little Falls, NJ 07424
USA
wfuller@pauloabbe.com ■
Info
Thank you for all your coments and recomendation.
I need to say also that each fluid bed dryer (there are three) has a positive disp. fan of 41,000 CFM. The temperature at the outlet of the dryer will be 60 ºC.
Do you think is too large for a baghouse? or there is no problem with that.
Thanks ■
Dust Collection At Fluid Bed Dryer
Dear Mr. Alvarez,
High humidity need not necessarily be a problem to a baghouse, but test to
characterize your gases and dust would be needed. We would be very glad to assist you with such work. Please send us any more information if you are
interested in a study.
Regards,
Cameron Harris
CameronH@hgeng.com ■
Dust Collection At Fluid Bed Dryer
The equipment that would take care of the dust collection portion of this
particular application would best be supplied by companies such as American
Air Filter, Donaldson/Torit, Griffin Environmental and the like.
Our product (compressed air filtration and purification) would then be needed to operate the bag cleaners on these types of collectors.
The issue of condensation in the exhaust line is not uncommon, and is
typically handled by having insulation on the pipe leading from the source.
Bill Ulrich
Van Air Systems Inc.
2950 Mechanic St.
Lake City PA 16423-2095
814-774-2631 Phone
800-840-9906 Phone
814-774-0778 Fax
814-774-2636x254-direct
bulrich@vanairsystems.com
www.vanairsystems.com ■
Dust Collector
Dear Sir,
We have notification via Mr. John Whitehead, Shapa Gen. Secretary, that you
may have a requirement for a dust collector to serve a fluid bed dryer.
DCE Donaldson Ltd. is a major manufacturer of dust control plant in Europe
with experience of dryer applications in the food industry. We would be
pleased to receive any formal enquiry you may have for this application.
Our address is DCE Donaldson Ltd., Humberstone Lane, Thurmaston, Leicester,
LE4 8HP, United Kingdom.
Tel 0116-2696161 Fax 0116-2564268
Regards,
Ken Wright
Sales Manager
Mobile no. 07774-276562
kwright@Mail.Donaldson.com ■
Filter Bags For High Moisture
Many filter bags claim to handle moisture with dismal results. We represent a high tech company which manufactures and sells filter bags which will meet your expectations. These filter bags contain 1.6 to 2.7 times the filtering area of the typical filter bag bag, not pleated, and are specificially designed to operate under conditions of one gallon per minute of water, per bag, and have the unique ability of recovering. We have used these even in high temp. applications such as cement dust @ 400 F and hot moist air and experienced no hydrolysis. Nomex has a tendency to fail in short order under these conditions. The other attribute is we require only 60-80 psi cleaning air.
Please get back to us for further review.
Thank you,
GW Parks ■
Fluid Bed Dryer´S Dust Collection
We are a supplier of the so called Bulkflow Cooler and I was just wondering if this type of equipment used as a Drier might be a solution for you. It will for sure totally eliminate the need for a dust collection and - or air handling system.
Please visit our website www.bulkflow.com
G Boeyink
manager Europe
boeyink@bulkflow.com
+31 543 531 861 ■
Re: Fluid Bed Dryer´S Dust Collection
Low temperatures will cause moisture in the air to condense on the bags if the temperature reaches its dew point.
Wet bag surface will then result in premature plugging of the bags.
You should calculate the dewpoint for your process and ambient conditions and if you do reach dew point the solution would be to insulate the baghouse.
Also consider using dry air to pulse the bags.
Use of PTFE bags or membrane bags will not solve this problem.
Regards,
Amrit Agarwal(Tim)
Pneumatic Conveying Consultants
polypcc@aol.com,or
pccsolids@aol.com ■
Fluid bed dryer´s dust collection
I am involved right now in a banana chip project that includes in the process drying of the banana slices using a fluid bed dryer.
We have a concern regarding the dust collection of the flow coming from tha dryer, because of the % of water vapor in it. We are planning to use a baghouse but we are concern for dust build up on the bags.
Does any body have had a similar experience, what would you recommend?
Best regards
Braulio Alvarez ■