As the name says, yes its pressurized and DIY and pressures of 100PSI can be achieved but its risky. Why risky, will come later.
how to:
this is based upon the chemical reaction between Citric Acid and Baking Soda, which when reacts in aqueous medium forms CO2 as one of its products.
The Reaction:
C6H8O7 + 3NaHCO3 -> Na3C6H5O7 + 3H2O + 3CO2
Citric Acid(C6H8O7) reacts with
Sodium Bicarbonate(NaHCO3) to form
Sodium Citrate(Na3C6H5O7), Water(H2O) and
Carbon Dioxide(CO2)
WARNING:
The reaction is v fast and can be explosive if correct measures are not taken just like nuclear fission
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
But dont worry, the system that has been discovered by someone, is quite fool-proof with a little attention on our part.
A glimpse of how it looks-
Now lets move on to how to make one.
List of things that are required-
1) 2 Liter Soft Drink Bottle(DO NOT USE ANY OTHER BOTTLE as other bottles may not be able to hold the pressure) – 2
2) 200 gms Citric Acid
3) 200 to 262.5 gms Soda (DO NOT USE MORE THAN 300gm)
4) Bottle caps(Soft Drink one or the Chinese ones) – 2
5) Pressure Gauge - 1
6) Needle Valve(flow/bps controller) - 1
7) Ball Valve (on/off) -1
8) PU connectors(6mm) – 8 to 10 pcs
9) PU Pipe (6mm) – 1m to 2m
10) Diffuser - 1
11) Check Valve (Optional) – 1 to 2 pcs
12) Bubble Counter – 1
13) Teflon Tape (to make leak proof joints)
14) Wrenches of different sizes
15) Suction cups – 2 to 4 pcs
A pic of the main parts required-
From left- the Pressure Gauge and its PU connector, 1st Cap(Chinese) Ball Valve (steel and red) and its PU connectors, flow Controller and its PU connectors and 2nd Cap (Chinese).
I am keeping the caps for reference if any one wants to use it, but I personally dont use them. I dont like their quality and hence dont have much confidence on them as they break at high pressures(60psi and above).
I use the soft drinks bottle caps only.
Assembly-
1) Make two holes in each of the caps(2 caps)- Hole diameter optimal is 3mm)
2) Take one cap, insert a pipe of size 2". keep one inch inside and one inch outside. this pipe will connect with Pressure gauge later.
3) Take another pipe of twice the bottle length. insert it into the cap and keep the pipe length a little more than the bottle length inside.
4) the other half length that is out side, insert that end into another cap to a length of 2" max in the inside.
5) take another pipe of 2" and like step two, do it for the second cap.
Once this is done.
its time to connect the PU connectors to their parent components. Before you connect the connectors to the components, wrap some teflon tape on the male threads and then make them sit tight there. While you are manually inserting the connectors into the thread, neither it should feel tight nor loose. this will depend on how much tape has been applied. after a point you wont be able to tighten the connectors bu hand and then use the wrenches to tighten the joint. Will try updating with pics later.
![Smile :)](./images/smilies/icon_e_smile.gif)
secure the bottles to the caps.
6) the cap with the pipe till the bottom( lets call it A), attach the pressure gauge on it and ball valve to the one with both pipes smaller(lets call it B).
Now,
7) make a solution of 600ml water and 200gm citric acid and keep it in bottle and secure it to bottle A.
9) pour 300gm baking soda(not baking powder) in another bottle and secure it to cap B.
MAKE SURE ALL THE JOINTS TILL NOW ARE LEAK PROOF.
10) Squeeze bottle A so that the citric acid solution goes to B. once it reaches the baking soda, the reaction will start and CO2 is generated.
keep sqeezing untill you get a pressure of 5-10psi.
Alternatively, after 1st squeeze,wait for a couple of mins, and thn open the ball valve a little to pull citric solution to B. one it reaces B, turn off the ball valve. let the reaction settle down and do it again to increase pressure. but with this, u have to loose some co2.
once a pressure of 10-20psi is reached. let it be there if the diffuser can work with that pressure. keeping the system at lower pressure, gives you ample buffers from an accident.
now take a pipe of length convenient to you and attache one end of it to the ball valve and another to the flow controller.
one last pipe is required for connection of the flow controller and the diffuser in the tank.
Please refer to the pic above.
Once all are done, close the flow controller completely, open the ball valve and start adjusting the flow controller.
My suggestion would be to keep at max 1.5bps.
Working Principle- if the pressure is set at suppose 10 psi (gauge showing), both the bottles hav 10psi pressure, so when the co2 from bottle B flows out, the pressure in bottle B is lessened and Bottle A is higher, so to compensate the pressure lost, the citric solution comes to bottle B, reacts and again settles the pressure back to the 10psi in both the bottles and this is how the cycle keeps on going.
Problem: its arises when there is too much water resting over the baking soda, making the reaction slower and pulling in more than reqd citric acid.
due to the more than reqd citric acid inflow in B, there can be pressure hikes and in those scenarios two things can be done-
1) tilt the bottle A in such a way that the pipe doesnt remain in contact with the solution.
2) draining the water from the bottle B. While doing this, please please please keep in mind to open the bottle A. If you open bottle B first the citric will siphon from A to B can will make moms/wives v angry coz spillage on floor will make the floor white nearly permanently
![Neutral :|](./images/smilies/icon_neutral.gif)
Other than this, if there is any doubts, please do feel free to ask.
![Smile :)](./images/smilies/icon_e_smile.gif)
Finally the setup looks something like this- Sorry that I dont have all the proper pics now, will update illustrative pics later on.
Thank you!!
![Smile :)](./images/smilies/icon_e_smile.gif)