Looking for kiln help

[RickJ]

I just filled my new kiln with its first charge today and I am hoping for some advice as things are not going as planned.  
I have run a different setup before but wanted to make some changes and this style seems to be the proper way to go but I have almost 0 airflow through my stack, barely wobbles a lighter flame.  
Admittedly, I think there is too much airspace volume on the sides of the stack and it may be too wide and possibly too tall?  But I though I'd see some airflow.  
You can't see a whole lot from the photo but it's 4.5' wide, 6.5' tall and the bottom 1/3 is 10' lumber while the rest is 8', and the stickers are 3/4".  I had planned on hanging 3 fans from the ceiling but the 3rd hasn't arrived yet so just running 2, but I can't see a 3rd fixing my issue completely.  
I used plywood to seal between the fans as well as to each wall, have a sheet of ply on top of the stack and another running from the bottoms of the fans to the top front edge of the stack.  I mounted more ply on the ceiling/wall at a 45 in front of the fans to direct airflow down.  
There is 39" of airspace between the sides of the stack and each wall, and I used baffling on the ends of the stack to seal it to the wall.  

Is there something obvious that I am missing?  Or does anyone have any suggestions?  
There is a decent amount of airflow coming out of the fans, albeit chaotic but I stuck a house fan on one side of the stack to test it and it picked up the airflow going through quite a bit.  There is no rating on the fans, they are from an Ebac dehumidifier system, 18" 1/3hp.

[JoshNZ]

I was pondering this last night I thought I'd wait and see what the pros had to say surprised noone answered!

My only thought was you're lacking horsepower for the size of your stack. It is quite tall. I assume your stack is 10ft long and you have baffled it to the ends of the container walls? There's not a 2ft gap at the end of the 8ft boards?

Mine is setup in a 20ft reefer which leaves maybe a 17ft long stack, I don't go any wider than say 3ft, and no higher than maybe 5ft. I have 4 fans along the ceiling each rated at 200w, say 1/4hp each. With that setup I can feel air flow from the back of the stack, it's just draughty I don't know what it would do to a lighter flame. Definitely noticeable with my hand.

Have you baffled/shrouded the fans? They're not just hanging from the ceiling by themselves? Ideally you want to create two seperate chambers within your container, one on each side of the stack and a circular cutout in that vertical baffle between the chambers for each fan. Should be no way for the air to get back to the fan without going through the stack, not around either end or over or under.
I think it is less about creating air flow through the stack and more about creating a positive plenum on one side of the stack, which will result in airflow across the boards as it moves to the negative side.

Take a few more photos might help, as you say hard to see what's going on in that photo.

Your third fan might make all the difference.

[Southside]

I think your stack is too wide and the space between the stack and the walls is to big for starters.

I run 6 fans in my kiln and the stack is 42" wide, about 18" of space between it and the pressure side wall, maybe and 24" off the non pressure side. 

[RickJ]

The fans are baffled as you say, as well as the stack.  The length of the stack between baffles is maybe 7', I blocked off 6" or something on each end.  
I was sure I had the idea right but somewhere in my execution it went wrong.  Maybe that 3rd fan will do it or maybe I do need to shorten my stack to wall distance somehow.  Or a combination of the 2.  
There is a lot of air coming off the 2 fans all the way to the floor on the positive side, and I'm happy with the baffling around the stack, no big holes, but just nothing getting through to the negative side.  
My airflow meter isn't showing actual numbers but just for comparative reference it shows 300cfm in front of each fan and between 0 and 7 on the negative side of the stack. I put a house fan on the positive side and it boosted up to 35. 

[K-Guy]

I would say that Southside is right and I also recommend you contact Ebac for what they recommend for chamber sizing or plans if they have them.

[wkf94025]

I use sheets of black-painted 1/2 CDX to shield the load from direct sun, and baffle off that.  Two kilns, whose overall dimensions are 22' long, 4' tall in front, 8' in back, and about 5' from front to back.  Across the high side of the 22' of plywood sun screen I have installed 9 fans, every 2' or so, 5" fans, 110 cfm each, pushing air down the back of the kiln.  I have some BT-enabled wind gauges that I plan to geek out with to see what kind of flow I have through the stack, but seat of the pants tells me I have good airflow, and drying results are very positive.  I've done four full loads of Doug Fir and Redwood over the past year, and whether I weigh a one-cubic-foot test piece (for DF timbers) or use cheap pin moisture meter (on 1x8 Redwood), the graph of moisture weight loss is very much as expected.  Redwood unloaded last week was 7% MC with very little checking, so I must be doing something right.  Though softwoods obviously the ideal Year 1 Classroom.