Need method to open/close a 4" vertical tube to adjust spillover level

[Qmavam]

TL;DR Summary

I have a 4" vertical thin wall aluminum spillover tube, I want the spill over tube to have two adjustments besides the full height. There is not a lot of room to make these adjustments, but probably just enough depending on solution. I have include some relevant info in the drawing. My first idea is to have internally threaded inserts heli-arced around the circumference of the 4" tube, and put threaded plugs in the holes.
Thanks, Mike

 

[Baluncore]

Welcome to PF.

Consider an elastic rubber sleeve that can be positioned on the outside of the 4" tube. To selectively block holes, slide it up or down.

An alternative would be a harder plastic sleeve that slides inside the 4" tube.

 

[jrmichler]

Consider an elastic rubber sleeve that can be positioned on the outside of the 4" tube.

Such a sleeve can be found at many hardware stores. This image is from Amazon for a 4" sleeve:

Make sure the hose clamps are stainless steel, including the clamp screws.

 

[Qmavam]

Consider an elastic rubber sleeve that can be positioned on the outside of the 4" tube. To selectively block holes, slide it up or down.

An alternative would be a harder plastic sleeve that slides inside the 4" tube.

That is something I have thought about, I like it as an easy solution. The downside, but not insurmountable
is the fit around, or internal to the tube. I'm not sure how concentric the 4" tube will be. There is very low pressure (1PSI) so it doesn't need to hold pressure. It has to be tight enough to not leak, but easy enough to adjust.
Hmm... maybe a hollow tube with o-rings that will seal above and below the over flow holes. I have added my concept of a sliding hollow tube slug with o-rings to my drawing.

A piece of info I neglected to add, this will run at 90*C, but only during treatment, not when an adjustment is made. Adjustments would be only occasional.

Thanks, Mike
P.S. I have drawn with paint for 28 years, maybe it's time I learn Solidworks :-)

 

[Qmavam]

Such a sleeve can be found at many hardware stores. This image is from Amazon for a 4" sleeve:
View attachment 330992
Make sure the hose clamps are stainless steel, including the clamp screws.

Sorry, I added info to my last post about temperature, the system will run at 90*C, the sleeves are made of Elastomeric Polyvinyl Chloride only good to about 50*C. I thought these were a great solution to another problem I have until I found the temperature problem. I haven't found them in a different material, but that doesn't mean they don't exist.
Thanks, Mike

 

[Qmavam]

Still open for suggestions on my question.
Thanks for your help, Mikek

 

[jrmichler]

Hmm... maybe a hollow tube with o-rings that will seal above and below the over flow holes. I have added my concept of a sliding hollow tube slug with o-rings to my drawing.

A metal tube with O-rings would not need the drilled holes because the top of the sliding tube would set the spillover height. And the O-ring friction would hold it in position.

Another idea is a piston ring compressor. Loosen using the key, slide into position, tighten, remove the key. This idea would use the drilled holes. Any auto parts store should stock them. Image of a piston ring compressor from Amazon:

 

[Qmavam]

A metal tube with O-rings would not need the drilled holes because the top of the sliding tube would set the spillover height. And the O-ring friction would hold it in position.

Hmm... it doesn't work out that way. Both tubes are electrodes so must be conductive. Even if the sliding tune were redesigned as an adjustable height tube, the O-rings would act to insulate the sliding tube from the fixed tube. however there may be a kernel in the idea that could result in an adjustable height tube.

Another idea is a piston ring compressor. Loosen using the key, slide into position, tighten, remove the key. This idea would use the drilled holes. Any auto parts store should stock them. Image of a piston ring compressor from Amazon:

That is a nice idea, we would need to weld an extension onto an Allen wrench to reach the length. Also, I don't remember the method used to keep the piston ring compressor in it tight position. I wonder if there is room to release it.

Thanks for those ideas !! Mikek

 

[DaveC426913]

Is the overall structure (the aluminum tubes) outside your control? i.e. are you forced to retrofit your solution?

Because, if you had say in the design of the aluminum, I'd design the orange and blue overflows differently so that they default to being closed and your mechanism opens them.

 

[Qmavam]

Is the overall structure (the aluminum tubes) outside your control? i.e. are you forced to retrofit your solution?

This is all design phase. Trying to think of every aspect before build. We started with small scale test tube with a center electrode surround by and aluminum tube, Then built a 2' x 2"x 34" tall all glass vessel with aluminum tape as the electrodes and also working on a zigzag flow pattern stainless steel vessel that is yet to be completed because of insulating problems. This is a third iteration in an attempt to get a more permanent flow through system. It is still small scale but big enough.

Because, if you had say in the design of the aluminum, I'd design the orange and blue overflows differently so that they default to being closed and your mechanism opens them.

I'm very open to ideas, not sure how to implement what you describe. Can you provide more info?
Thanks for your ideas, Mikek

 

[DaveC426913]

Use the quote feature.

I'm very open to ideas, not sure how to implement what you describe. Can you provide more info?
Thanks for your ideas, Mikek

I had no specific plain in mind.

I am just thinking that the design you have sort of defaults to 'flow' and then you have to design a mechanism to close flow, which might be more complex than designing it where the default state is 'no-flow', and then you can design a movement that opens to allow flow.

(Heh. Got access to a junked clarinet or sax?)

 

[Qmavam]

Nice thought, but I want, simple, so we can do most of the work and only have to hire out some machining.
I'm helping my son, a chemist, I have an electronic background, we are try to do mechanical engineering.
So I'm soliciting ideas and trying come up with an idea that works and is something we can do!
Thanks for your input, Mikek

 

[Lnewqban]

Welcome, @Qmavam !

An additional idea:
To reduce the flow entering the 8-inch tube. You could use a pump of variable velocity, three position valve (if the pump is of centrifugal type), or two valves and by-pass lines.

 

[Qmavam]

Welcome, @Qmavam !

An additional idea:
To reduce the flow entering the 8-inch tube. You could use a pump of variable velocity, three position valve (if the pump is of centrifugal type), or two valves and by-pass lines.

The flow rate is fixed by the output from another process. The treatment time in the vessel will be determined by whatever opening is chosen for the spillover. Thanks for the input, Mikek

 

[Tom.G]

How about making the inner tube a telescoping design so you can adjust its length as needed?

Alternatively, again the inner tube is two concentric tubes, the inner one with holes in different positions so its holes can be rotated to line up with the different height holes.

Cheers,
Tom

 

[DaveC426913]

How about making the inner tube a telescoping design so you can adjust its length as needed?

And control the flow by using V-shaped slots.

 

[Qmavam]

And control the flow by using V-shaped slots.

View attachment 331116

Flow volume is not the desired outcome, flow level is, the higher the level the longer the treatment time.
The telescoping tubes may be a solution, although probably harder to implement. At least for non machinists. Still all of this needs to be a conductor that is insulated, setting up an electrostatic field but not a conductive path.

"Everything looks easy until you actually try to do it!" :-)
quote of, someone, somewhere, that has had to have said this!

 

[Lnewqban]

Another idea:
To reduce the annular volume between both tubes by inserting enough mass of an appropriate and chemically compatible material.

That will reduce the cross-section, and proportionally the treatment time, without the need for holes or related valves and mechanisms.

An inverted bucket shape that is locked at two different heights respect to the exterior aluminum tube could work... at least in my mind.

Enough annular gap (or vertical grooves) between this piston and the 4-inch thin wall aluminum spillover tube will facilitate the up flow to the top of that tube.
Please, see attached drawing.

 

[Qmavam]

To reduce the annular volume between both tubes by inserting enough mass of an appropriate and chemically compatible material.

Kind of like putting a brick in the toilet tank to increase water level height but reduce the Volume. Clever!
Thanks, Mikek

 

[Flyboy]

Hmmm. If the objective is to keep it as simple as possible without machinist skills, I'd argue for using a sleeve that's just long enough to cover both sets of holes. Want to use the lower set? Slide it up a bit. Use the upper set, slide it down. Flow over the top? Cover both.

I think you'll at least have to have some o-rings to get a good seal while still providing that insulation. But, without machinist support, that's kinda asking for trouble. You'd want a retaining groove to seat them in. ANd, you'd have to choose the material for the o-ring based on the conditions, both chemically and physically, present in the tank.

 

[Qmavam]

Thanks for that input, I am trying to keep costs low, but once a design is fixed, we can hire some machining work out.

 

[Baluncore]

I am trying to keep costs low,...

Put a 4" pipe thread at the bottom. Screw in, by hand, piece of 4" male taper thread pipe from a selection of different lengths.

Put a loose 4" socket at the bottom. Drop in a plain 4" pipe from a selection. Gravity will keep it there.