Dry Blower

[1968falconxt]

Hi all,

Time for a new project.....

I am currently designing a dry blower for use up at my property near Bendigo. I hope to build it in a couple of weeks but need to sort some things out with the design first. I have read every build thread on dry blowers on the forum but am left with some questions.

What rough angle should the bottom unit be? (Obviously it will need adjustment)
Is the hopper angle critical?
What diameter perforations should I use on the hopper screen?
Do I have enough riffles? The Keene 151s uses 8 riffles, 4 of which are just at right angles.
Is the angles of my end 2 riffles critical? My riffle height is 25mm. Is the height critical?

I am open to suggestions as I want to build it right.

I will be making it all out of mild steel sheet 1.6mm thick as that is what is available to me. The blower bed is 370mm wide by 900mm long to give you an idea on its size.

 

[shakergt]

Nice drawings. Do you use a CAD program? If not what program do you use? These guys might be able to help you out with it. If you have seen Aussie Gold Hunters I am sure you will recognise them.

https://www.facebook.com/goldprospectingtourswesternaustralia/

 

[1968falconxt]

Thanks. I use Solidworks to do all my CAD and then get everything laser cut and folded up at work. I haven't seen those guys use a dry blower before?

 

[shakergt]

nice car by the way

 

[1968falconxt]

I have spent a bit more time on the design. I have opted for 10mm holes on the hopper classifier. The classifier can easily be changed to different sizes. The hopper also has an adjustable opening to vary feed rates onto the riffle bed. There is also adjustment on the hopper angle, riffle bed angle and position in relation to the hopper. The base will be mounted on chains & springs. I have also increased the length of the hopper significantly.

I only need to sort out a fan design and finalise the riffle design and I can then start fabrication!!!

 

[Keitzy]

Make the legs taller, it'll build up with tailings end of the riffle tray real quick being that size..

 

[Keitzy]

Little L bracket at the back of the riffle box to slide the tray under to.. keeps the whole thing clamped down with the front buckle as well

 

[1968falconxt]

Thanks, I will raise the legs as you make a good point.

It does have a bent lip at the back that the riffle tray slides under to hold it in place. It's just not easy to see in the pics.

 

[shakergt]

Looks real good. nice and simple. Would love to see photos of it when made

 

[1968falconxt]

Looks real good. nice and simple. Would love to see photos of it when made

I'll be uploading photos as I go along in the next few days. Shouldn't take long to build, fine tuning it to actually work right will likely take a while

 

[shakergt]

I was just thinking are the riffles in the bottom adjustable? I am no engineer but having adjustable riffles might be useful. You could adjust the size of the bays and so on with adjustable ones.

 

[Keitzy]

Sorted a shaker fan yet.?

 

[1968falconxt]

They aren't adjustable, but you have made me think.... I don't even know what angle they riffle should be yet. I was hoping someone would be able to help me out there.

I haven't sorted out the shaker fan yet. I am still trying to find out exactly what is required

 

[Occasional_panner]

With the hopper, punch plate tends to let material flow off and fall to the ground, expanded mesh tends to hold onto it, and when worked with a shovel seems to break it up better.
Bloody shame I just got rid of a heap that was lying here for 3 years last week. :|

Don't get too greedy with the riffle tray area, you'll need enough power to run properly. Too big tray and not enough air and it won't work.

Look forward to seeing your build :Y: :Y: :Y:

 

[Dihusky]

Interesting design, I think the angle of the riffle tray will be influenced by the vibration mechanism, too steep and everything will jump off the end, to shallow and nothing will move down the tray, so having an adjustable system based on the level of vibration and size/type of dirt you are putting through will allow for optimum collection of the heavies.

 

[1968falconxt]

With the hopper, punch plate tends to let material flow off and fall to the ground, expanded mesh tends to hold onto it, and when worked with a shovel seems to break it up better.
Bloody shame I just got rid of a heap that was lying here for 3 years last week. :|

Don't get too greedy with the riffle tray area, you'll need enough power to run properly. Too big tray and not enough air and it won't work.

Look forward to seeing your build :Y: :Y: :Y:

Thanks, I will use expanded mesh instead based on that. I can understand how easily dirt would just slide off punched plate.

Do you think my riffle tray area is too big? it is 290x900mm. I was planning on using a cheap leaf blower from bunnings, approx. 350-400cfm. If this sized dry blower needs a significantly larger (much more expensive) blower motor, then I will need to reduce its size.

 

[bluejeansronald]

Hi Mate, Wobble fan and cloth can be bought from reeds prospecting, Cheers.

 

[1968falconxt]

I downsized it after reading about the labour requirements to run one that size. It's now roughly the size of the Keene 140 instead of the 151.

My bits are all folded up now. I have quite a few hours ahead of me welding it all up now.... Hopefully it'll be ready for powder coating later this week.

 

[shakergt]

Looking good

 

[Dihusky]

Interesting jigsaw puzzle, hope it all fits...