Thread: My Thien dust cyclone stopped working

I think it is because there is not enough air moving through the system to setup much of a cyclone. The dust laden air takes the shortest route through the Thien to the dusty. Try it with something else open to get more airflow.

Pete

This is the 4th example of this I have seen/heard about.

If your system is not collecting chips then you simply don't have enough flow (CFMs).

In the other three cases what had happened was the DC filters/bags have become so clogged with fine dust that this has seriously impeded the flow.
This is the big problem with separators and cyclones, they don't filter the fine dust and this more readily clogs the filters/bags. In one case the bag was so badly clogged with fine dust that had impregnated the fibres of the bag that even vigorously washing the bags did not fix the problem. A complete mixture of sawdust (ie coarse chips and fine dust) is a PITA to keep empyting BUT less likely to clog bags. My guess is this will be at least part of your problem.

Assuming your filters/bags are OK, a 63 mm hose plus a separator is far from ideal for generating maximum flow which is also important for capturing fine dust.

A 2HP DC (with a clean bag/filter and no hoses attached and the 4" Y-port adapter removed) is capable of 1000+ CFM.

As soon as 1 x 4" hose is attached anywhere in the system the DC flow drops to ~400 cfm. Adding a separator drops this to ~280 CFM.
As soon as 1 x 2" hose is attached the DC flow drops to ~125 cfm. Adding a separator drops this to ~65 CFM.
A 63 mm hose will be somewhere closer to the 2" than the 4" hose.
Most people do not realize that 4" or smaller hoses and separators are flow killers (and poor fine dust collectors) as hose wall friction does not permit air speeds to increase enough to match the smaller diameters.

To maximise the flow from a 2HP DC you need
- a clean filter/bag
- remove the separator and learn to live with regular cleaning bags
- remove the 4" Y-port adapter and replace it with a 150 mm adapter
- use 150 mm hose
- adapt machine ports to accept 150 mm hoses.

There is no problem with chips hitting impellers. I have seen 30 year old DCs that have been used to collect big chips most days and, yes they were worn but not enough to prevent them from still working correctly.

Thanks for your reply, Pete, you put your finger on the problem.

BobL's response was a real eye opener for me. You have stated the problem quite clearly and logically, and added measures that can fix the problem, so many thanks for this.