Hi I'm Will, new member from the UK here.
I've joined because I've decided to build a Thien top hat for my dust extraction system, after lots of reading here I have gleaned lots of useful knowledge, I still have a couple of questions.
So, my plans are for a 100mm diameter PVC ducted system with a round to rectangular transition feeding into a 438mm diameter separator through a 40mm wide drop slot into a 70l dust bin below.
The (100mm dia) round to (195mm x 40mm) rectangular transition is built from 3mm plywood and I have started on the bottom plate of the separator. I plan to use a 550cfm blower to power the system.
Various calculations show that I should achieve about 6800fpm velocity through my 100mm pipework which is plenty more that the 4000fpm minimum required to entrain air with dust.
The transition's rectangular end is 195mm high and 40mm wide to match the drop slot width. The round end is aligned with the top inner face of the rectangular end to force the are to expand downwards towards the drop slot prior to entering the separator unit. Is this theory correct or should it be aligned with the bottom inner face of the rectangular end?
I have a question regarding the rotation direction through the top hat in relation to the blower unit. Is there any benefit to matching these? I don't really want to have to build an air straightener as well.
Anyway I hope someone can help. Thank you in advance
I've joined because I've decided to build a Thien top hat for my dust extraction system, after lots of reading here I have gleaned lots of useful knowledge, I still have a couple of questions.
So, my plans are for a 100mm diameter PVC ducted system with a round to rectangular transition feeding into a 438mm diameter separator through a 40mm wide drop slot into a 70l dust bin below.
The (100mm dia) round to (195mm x 40mm) rectangular transition is built from 3mm plywood and I have started on the bottom plate of the separator. I plan to use a 550cfm blower to power the system.
Various calculations show that I should achieve about 6800fpm velocity through my 100mm pipework which is plenty more that the 4000fpm minimum required to entrain air with dust.
The transition's rectangular end is 195mm high and 40mm wide to match the drop slot width. The round end is aligned with the top inner face of the rectangular end to force the are to expand downwards towards the drop slot prior to entering the separator unit. Is this theory correct or should it be aligned with the bottom inner face of the rectangular end?
I have a question regarding the rotation direction through the top hat in relation to the blower unit. Is there any benefit to matching these? I don't really want to have to build an air straightener as well.
Anyway I hope someone can help. Thank you in advance