Revision as of 17:49, 28 February 2021

This one says 70% efficient - really? [1]
CFM of 20 gets 0.5 hp about. 1 cu m is 35 cf. 1 cu m at 190 atm is 7000 cf, at 20 cfm gives 350 minutes or almost 6 hours.
Piston type mixer motor - 7 cfm, 0.2 hp - $250 - [2].
- One k-type cylinder gets me 35 minutes of this power. That's at least a start, but too short duration for practical use. Adiabatic.
14 cfm gets me the right power - 0.4 hp or 300W.
17 cfm - 0.33 hp - 250 W - [3]

Power Out

1 cubic meter of air storage - at 200atm - gets you 7000 cfm at stp. Since we need to save 10 atm to run, have 190 atm available - so 5% negligible loss - most is usable air. This is 500 minutes of air - 8 hours - of 300W - or 2.4kW hrs! This is just plain adiabatic.
- One Type K tank gets 120Whrs.
Thus, having access to 1 cu m of stored air - is key - for an inefficient storage system.
Going to isothermal - we are 2.5x better
Compressed air with heat would be the way to go - where we store the thermal energy of compression via a heat exchanger.

2" pipe - 10' - is $33. It is about 6l volume for 10'. 8 of these equal a Type K cylinder in volume. Same price.
Metals depot - 12" schedule 40 pipe, 6' long, is $726. That is 1/2 cu meter. Getting there for storage - but working pressure is 370 psi and burst is 3000 psi. Needs reinforcement.
How about 12" PVC - 3D printed, reinforced with fiberglass winding? That sounds like a possible idea for 2000 PSI air tanks on the cheap. $100 for pipe, then winding after that.
Or - Type IV pressure vessels, all composite, from HDPE liner and wound with 500,000 psi+ tensile strength fiber (glass or carbon)

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 *CFM of 20 gets 0.5 hp about. 1 cu m is 35 cf. 1 cu m at 190 atm is 7000 cf, at 20 cfm gives 350 minutes or almost 6 hours.
 *'''Piston type mixer motor - 7 cfm, 0.2 hp - $250 - [https://www.ebay.com/itm/New-Air-Drive-Pneumatic-Radial-Piston-14mm-Shaft-Motor-0-2HP-900RPM-Mixer-DIY/271399029996?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D230924%26meid%3Dcadef6bd62dd4e26b2999e183e5f2b18%26pid%3D101195%26rk%3D4%26rkt%3D12%26sd%3D303335987408%26itm%3D271399029996%26pmt%3D0%26noa%3D1%26pg%3D2047675%26algv%3DDefaultOrganic%26brand%3DUnbranded&_trksid=p2047675.c101195.m1851]. '''
-**One k-type cylinder gets me 35 minutes of this power. That's at least a start, but too little for practical use. Adiabatic.
+**One k-type cylinder gets me 35 minutes of this power. That's at least a start, but too short duration for practical use. Adiabatic.
 *14 cfm gets me the right power - 0.4 hp or 300W.
 *17 cfm - 0.33 hp - 250 W - [https://www.flexibleassembly.com/content/files/Ingersoll-Rand/Ingersoll-Rand-SM-Series-Lube-Free-Air-Motors-Specifications.pdf]