Another HF DC set up

[Gerry]

Hi, this is my first post on this forum. Thanks so much to Phil and everyone for all the details and experiences, as I've now built one system for my 2 1/2" shop vac system and am upgrading to my new HF DC.

This is what I've done thus far:
1. I have installed a Thien baffle in my new HF DC, with good results connected to one machine.
2. I have built a Thien baffled chip separator in a 30 gallon galvanized barrel. The elbow is in the counter clockwise direction, with the vacuum source pipe protruding 1 1/2 inches below the inner surface of the cover. ( same as photo from Phil's site)

Running the DC by itself, I noticed that the upper bag does not inflate that much, and
when I hooked the two together, I was a bit surprised at the result:

1. The upper bag does not inflate as much as with the DC alone
2. The lower bag inflated more firmly than it had as a separate DC, and
3. when I shook the filter bag, there was visible dust coming from it.  ( I have since run it as a stand alone system again with out the dust-from-the-bag issue)

My questions are:
1. as the DC is clockwise in rotation direction, does the counter-clockwise rotation in the separator have any effect?
2. Does having a baffle in the DC and in the chip separator cause problems for the overall efficiency of the system?

Thanks in advance for your views and help here.

Gerry

[phil (admin)]

(1) Differences in rotation direction aren't a problem.

(2) There is no free lunch, the baffle and separator do provide a hit to CFM.  But nowhere near as much as a clogged filter.

Many people will use the separator in front of their big chip producers only (jointer and planer), and have the other tools piped directly to the DC (w/ baffle) to provide maximum CFM.

[Gerry]

Thanks for the quick response, Phil.

In my current, shopvac based system, I've used the clear plastic 2 1/2" kit to distribute the chip/dust collection points around my shop. I plan to use the existing system as a dust extraction source, connected to large dust generating tools. I have found a way to do this efficiently, in a two stage process, as long as I dedicate the extraction tool to the dust extraction function.

Similar to my current system, I've used 4" S+D pipe around the shop, well sealed at all junctions with Aluminum tape, the kind used on Pellet Stove Pipe. (This prevents ANY smoke from escaping, so I think it will do the same for fine particles) 

Of course, like the shopvac based system, I will open one gate at a time (the machine I'm using at the moment), to maximize air flow and dust collection. I must say it is astonishing to see the airflow even from one end of the shop to the other. Clearly, if there are any leaks in the system, or more than one gate open, the dust collection is GREATLY reduced. ( the difference between an air flow and a vacuum based system). 

That being said, I cannot see removing either baffle; The one in the DC is permanently installed, should I need to use it directly. The one in the chip separator is mandatory for it's function. I must say that your invention has made a huge difference for me in the number of times I've had to clean out the shopvac. I am hopeful it will provide a similar result with the new DC.

I do have a couple more questions: Any idea how much of a hit the baffle causes? by volume of air moved or by percentage?  Thanks again for your help.

Gerry :)

[phil (admin)]

I do have a couple more questions: Any idea how much of a hit the baffle causes? by volume of air moved or by percentage?  Thanks again for your help.

There are too many variables to make any generalizations, unfortunately.  I've done quite a bit of testing and have often been surprised by the ranges.