topbanner.gif
Login
Username

Password




Not a member yet?
Click here to register.

Forgotten your password?
Request a new one here.
Shoutbox
You must login to post a message.

snwcmpr
12/07/2019 9:29 AM
roar

snwcmpr
11/27/2019 11:44 AM
greenman

allenb
11/27/2019 11:04 AM
Nice! I know Netrix is going through things and tweaking as he see's issues

snwcmpr
11/26/2019 1:35 PM
I got an email that I had a PM. So, that is working for me again. greenman

snwcmpr
11/26/2019 1:33 PM
Howdy Howdy!!

Users Online
Guests Online: 6

Members Online: 0

Total Members: 6,285
Newest Member: thirdguess
In Memory Of Ginny
Donations

Latest Donations
Jared Brunette - 5.00
Daniel Boozer - 5.00
renatoa - 2.00
JitterzZ - 2.01
renatoa - 2.00

View Thread

Who is here? 1 guest(s)
 Print Thread
Fluid Bed Build
salperta
Hello!
Here is my first post, thanks to everyone for their invaluable insight in the threads I have pored over in the past.

I am starting a build for a fluid bed coffee roaster based on Linnaeus' brilliant 3d printed/cast design, as well as CK's masterly transparent fluid bed roaster, as I am an avid 3d printer myself, and a coffee lover, of course!

I have a bunch of parts kicking around, and plan to buy some as well.

HOWEVER, I am already stuck on figuring out how vacuum motors work. I have an old and broken Eureka bagless "optima" vacuum, which I disassembled, thinking I could repurpose the motor. However, due to the design (I think, or maybe it's the AC thing?), even when the polarity on the motor is reversed, the motor will only suck air through the main opening. It vents this air over the motor for cooling. I'm trying to figure out if there is a way I can make this motor work for my purposes of blowing in order to fluidize the bed.

I'm trying to figure out if I can print a chamber for the motor that will send the suctioned air out in a focused way. I think I would have the seal the vents which allow the air to cool the motor, and turn the motor into a "bypass" rather than a "flow through" design, but I'm not sure. I would imagine removing the steel sheath that currently covers the fan and forces the suctioned air back over the motor, and constructing a chamber like the basic blower vac picture attached.

My questions are:

1) Um, would this work?
2) Do I need to seal the vents which allow the air to pass through over the motor, in order to have enough air pressure going out the out-port?
3) If I seal the vents, how does one cool the motor?

I guess that's about it for this first step! Otherwise, I have collected a parts list and drawn some basic diagrams which I will posting as I move forward.

Pictures of the motor that I have are attached also, with the steel sheath both on and off.

Thank you so much in advance, I appreciate all the collected expertise and knowledge.

S
salperta attached the following image:
blowervacimage.jpg
 
salperta
Well no surprise the images didn't work except one. Here, hopefully, will be the pictures of the motor that I have.
salperta attached the following image:
20190616_190532_1.jpg
 
salperta
Blargh! It only attached one picture again. Sorry! Here's one more, hopefully it will give some insight.
Sorry and thanks again.
 
greencardigan
I use similar/same motors in my builds and just slide the motor into a PCV tube and seal around the diameter. They're usually a snug fit in 4" tube I think.

I wouldn't bother trying to convert it. Without the flow through cooling the motor, it may overheat. My motor noticeably warms the air flowing through it.

The only problem with the flow though design is that you won't be able to do much if any hot air recirculation.

The restriction of the beans and perforated plate with provide the pressure. No need to restrict it prior to that.
 
salperta
Thanks greencardigan, that's really helpful info. So do you have the air exiting in-line with the suction on the opposite side of the fan, where the motor is, like in the attached picture? (As opposed to at a 90 degree angle, as in a typical blower vac, like the picture of the one I attached in the first post?)

And Jack--thanks for the tip. I was merely lamenting my own inability to properly post pictures, not the sites! Hopefully I will get better at it in the future...
 
JackH
No problem, I have to check in case the site glitches.

I find that the #1 problem is the preview reply. It just wipes out the files in attachment. Wish I could get rid of it.
Filenames that use Linux reserved characters can also cause problems.
---Jack

KKTO Roaster.
 
CharcoalRoaster
JackH wrote:

Filenames that use Linux reserved characters can also cause problems.


+1 Check this in your filenames. I could never get images to upload properly until I discovered this little caveat.
 
greencardigan
salperta wrote:

Thanks greencardigan, that's really helpful info. So do you have the air exiting in-line with the suction on the opposite side of the fan, where the motor is, like in the attached picture? (As opposed to at a 90 degree angle, as in a typical blower vac, like the picture of the one I attached in the first post?)

Yes, the air exits in line with the small suction hole and around the motor. I've attached afew pics showing how I have mine in the tube.
greencardigan attached the following images:
withheater.jpg air-out.jpg air-in.jpg
 
salperta
Those pictures are super helpful, thanks again greencardigan. My motor is a bit bigger, about 5" diameter. Went out to find PVC for it, but unfortunately Lowes carries 4" and 6" PVC, but not fivethumbdown The hunt continues, though I may just have to print the part. We'll have to see! I've ordered most of my initial parts and when they arrive I'll take measurements and start designing the case, airflow, etc. I'll keep this thread updated in case anyone is interested and because I'll probably have questions too along the way. Thanks so far to everyone for their advice.
 
CharcoalRoaster
On my first build I used a spa blower boot to fit my vac motor and it has worked out really well. I don't know if you can still find them but here's a link to a pic of what it looks like: https://www.spaan...lower.aspx
 
salperta
Alright, so I've been working away. Couldn't find any spa blower boots, unfortunately, although that's the perfect thing, so I designed a case for 3d-printing, that does the same thing. The issue I'm currently facing is how to control the power on the vacuum motor. I had an ac/dc power supply sitting around, and i ran it through a dc speed controller, but it can only output about 198 watts, which I don't think is enough to really get the fan blowing enough air. How do people control the speed of their motors? Mine is a 120v 12amp model. I probably don't need that much power, but I do need more than 198 watts, I think. I imagine a variac would work, but high-amp variacs are pretty expensive, it seems. Any other suggestions?
Thanks so much, everyone!
Saul
 
salperta
OK, so a little more research today. Is this the proper item here: a 25A SSVR?

They don't recommend it for motor control because of torque, but since there won't be any load on the motor, maybe not an issue. Seems like others might be using these?

https://www.auber...cts_id=332
Thanks!
Edited by JackH on 06/28/2019 9:05 AM
 
salperta
Andddd I should mention I'm planning to control the heating element with an Arduino interfacing with my computer. I figured I would adjust the blower manually to keep circulation consistent throughout the roast. Wanted to mention that in case it changes the best way to control the blower. Thanks again, sorry for being so scattered.
 
allenb
salperta wrote:

OK, so a little more research today. Is this the proper item here: a 25A SSVR?

They don't recommend it for motor control because of torque, but since there won't be any load on the motor, maybe not an issue. Seems like others might be using these?

https://www.auber...cts_id=332
Thanks!


Since universal motors (most vacuum motors), behave more like a resistive load versus a true inductive load, there shouldn't be any problems using the SSVR to control it. Many have used AC dimmers of various types to control vacuum motors.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
renatoa
Depends of SSR type and how is controlled...
A ZC SSR for example, can't be controlled by phase angle, to act as a dimmer. He needs a random fire SSR for this task.
 
Jump to Forum:

Similar Threads

Thread Forum Replies Last Post
Transparent Fluid Bed Design Building a Coffee Roaster 111 12/02/2019 7:32 AM
Fluid Bed Roaster Build - bye bye Heat Gun and Flour Sifter Fluidbed Roaster 64 11/28/2019 7:18 AM
New Drum Build -- MAYBE Drum Roasters 2 11/25/2019 2:36 AM
Immersion Style Fluid Bed Concept Fluidbed Roaster 26 11/13/2019 5:31 AM
New 1kg drum roaster build Drum Roasters 8 10/10/2019 9:53 AM
Homeroasters Association Logo, and all Content, Images, and Icons © 2005-2016 Homeroasters Association - Logos are the property of their respective owners.
Powered by PHP-Fusion Copyright © 2019 PHP-Fusion Inc
Released as free software without warranties under GNU Affero GPL v3
Designed with by NetriX