Liquid release mechanism

[MikeHK99]

Hi All ,

I am looking to release a few ml of water inside a sealed cylinder.
Basically the water is contained in a small chamber (or capsule or cartridge etc) and needs to be released from the outside of the cylinder without opening the cylinder (as liquid may then come out)
I am looking for the most basic design which could be perforation (puncturing) or a twist design or similar.
Is there any existing technology for that as I can't seem to find anything online , your ideas or help would be highly appreciated.

Regards

Mike

 

[LittleInch]

Rather vague question.

There are many snap fit and twist fit connectors - think hydraulic hoses like this.

http://www.ebay.co.uk/bhp/hydraulic-couplings

Is that what you mean?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MikeHK99]

Hi LittleInch ,

I am sorry to be vague.
Essentially I am talking about a very small cylinder with active ingredients which only form a reaction once water is added.
The amount of water required is not much but needs to be contained separately from the other ingredients inside the cylinder.
The cylinder is airtight with for example a screw cap or pushbutton design which can release the water (which is already inside the cylinder but contained)
So I have thought about a cartridge inside the cylinder which can be punctured or broken by means of a push system or twist system , but the cylinder needs to remain airtight at all times (prior and after the water is released inside)

Hope that clears it a little.

Thanks

Mike

 

[btrueblood]

Does the cylinder have to be rigid? If not, use a plastic bag inside another bag, the user squeezes the outer and inner bags to burst the inner one. Or a thin glass tube inside a flexible plastic tube (think glow sticks),

If it must be rigid, is there a pressure rise inside the cylinder? This will affect the mechanism design, so we'd have to know how much pressure increase will occur. You might be able to make a burst disk rupture with a striker, by flexing a metallic or plastic diaphragm. There is a drink system that uses this idea:

http://www.vicapsystems.eu/products/caps/

https://bestinpackaging.com/2012/03/05/developments-in-dispensing-caps-an-overview/

 

[Compositepro]

Place the water in a cup inside your cylinder. When ready turn the cylinder upside down.

 

[gerhardl]

A miniature BFL-valve-like contraption acting as top lid of firm mounted inside cartridge. To be opened with prolonged to outside stem.

Or: small checkvalve in cylinder wall with nipple adapted outside to injector (syringe, clyster or piston-like.)

 

[MikeHalloran]

Sort of like btrueblood said, assuming the outer cylinder is hard.
Put the reactants in a glass ampule, and shake or impact the assembly to break the glass and initiate the reaction.
It will work better if there's some gas (air?) in the outer cylinder.

If both containers are completely full of liquid, release becomes more difficult.
A mechanical shaft pushed through a gland won't work because there's no place for the shaft to go as it's pushed in; it will feel like it's bottomed out and won't move.
If the shaft twists in the gland to strike the ampule with the end of a lever, then the volume of liquid inside does not need to be compressed, and release becomes possible.

We are of course all shooting in the dark here, absent some more clues about sizes, material constraints and such.



Mike Halloran
Pembroke Pines, FL, USA

 

[MikeHK99]

Hi All ,

Much appreciate your answers/help.
The cylinder is about 7cm in length and 2cm wide.
The container itself is made of ABS/PP plastic , wall thickness about 1mm so pretty strong.
Inside of the cylinder there compacted powder , leaving a gap of around 0.5mm all around the powder (in order for liquid to run down along the inner wall and penetrate the powders from the side).
On top of the compressed powder there is a 1cm space which can be used for cartridge/ampule to be placed.
The most important aspect is the fact that the container is sealed on both ends , ideally the cylinder can be manipulated from the outside to release the liquid inside of the cylinder.
I have seen the various liquid release caps for water drinks etc , but i don't think those systems are airtight.

Thanks again for all help and assistance.

Mike

 

[btrueblood]

They are certainly liquid tight, and could be made airtight. Mike's idea of a rotary shaft would be pretty simple to seal (e.g. with an o-ring).

 

[MortenA]

For industrial application - maybe you should look at something like what they use for "glow sticks"? That is if you dont mind glas shards in the mix after releasing the water?

 

[MortenA]

OK didnt read that the outside cylinder cant be bend and that the dimensions etc is rather fixed

 

[gerhardl]

Still intriguing.

To properly solve this, we still miss details of the total process like number and time for operations, how the reaction influences inside conditions, if pressure is needed for the water; if, how and when the cylinder can be accessed etc. Should have loved to see this through. But still, as a summary and addition to all above' possible solutions:

1) Water in upper chamer. Sealing plate in bottom with holes at edge, to be turned x degrees to seal or match holes in
plate covering powder section.

2) Syringe insertion from outside, syringe penetrating selfsealing rubber membran.

3) Bottom of water chamber at somewhat thickness with bored holes from center to powderchamber sidewall clearing. Water released by piston covering and sealing central bottom hole connected to borings, then lifted from outside. (Screwcap top large cylinder or piston to fill water.)