HOME-BRED STEAM POWER

In a post apocalyptic world, it is possible to have a homebred power source by building a steam engine. The task is straight forward engineering, but is not for the faint of heart. The following information is simply meant to be stored away in your file system and employed if the need ever arises. Given the fact that fuels may be in very short supply in the future, the time may arise when an alternative source for turning grain mills, water pumps, or generators may well be worth the trouble of building a steam engine.

I make no claims to being a steam power expert at all - I merely have described below what I have seen in operation.  Steam experts say a boiler must be just that - a regular steam boiler - and the concept of a weak pressure vessel makes them cringe.  They are the experts and it is wise to pay attention to their concerns.  Those wanting more information on steam power should contact the experts.  The Steam Automobile Bulletin is excellent.  It is produced by the Steam Automobile Club of America, www.steamautomobile.com.    While the primary interest of the club is the automotive use of steam engines, a steam engine could be used for virtually any application requiring power.

Working steam power projects are rare but great to see.  Here is a good one explained very well - with good photos, too.  Steam Powered Battery Charger

The basis for any steam system is of course the engine itself, followed by the boiler. The engine must have been initially designed to run on vapor rather than a liquid fuel, must be readily available, inexpensive, and easy to convert to steam power. You've guessed the answer already -- automotive air conditioner motors! In normal use, an automotive air conditioner motor compresses Freon gas (or a more expensive modern alternative that does not work as well) into a fluid, which takes considerable horsepower. But by putting steam into the back side of the compressor, reversing the rotation, the air conditioner motor becomes a steam engine capable of producing a considerable amount of power -- well in excess of 10 horsepower as rated for gasoline engines, and about 3 horsepower in steam engine ratings. The best available air conditioner motors for this purpose are the older General Motors "Frigidaire" models for Buick's and Cadillac's, as they were piston engines which can be reversed in rotation easily. The modern Wankel or rotary compressors would not work as well. Without proper lubrication these steam engines have a relatively limited useful life, but as they are cheap and readily available from automotive recycling yards, who cares? [Note: some steam power experts say that using an automotive air conditioner compressor for steam power is impossible.  I've seen it work, but I'm not an expert on steam engines.]

Obviously such an engine must be mounted securely to a very solid "stand" or platform, and the pulley connected via "V" belt to a very strong, ball bearing jack shaft on the same platform. It is from the jack shaft pulleys that useable power can be taken using "V" belts (of any convenient length), changing the diameter of the pulleys to obtain the desired rotational speed of the object being turned: an alternator, for example. The alternator in turn can charge batteries (if 12 volt), or power an electric pump motor if set for the correct voltage (Remember that a generator produces voltage in direct correlation to the rotational speed: increase the speed to produce 120 volts, decrease the RPM to produce 110 volts. Some older electric motors with brushes will have an output voltage equal to what they could produce if turned by an input of the proper voltage, so it is possible to build your own "generator" from totally salvaged parts. A taste of the future?)

Most automotive air conditioners have an electromagnetic clutch which requires a small 12 volt input to engage the clutch. Look on the back side of the condenser unit, right behind the sight level, and you will see the wires for the automatic low pressure cut off switch. Follow that wire to the air conditioner motor, and that is your "lead" for the 12 volt input source, which can be supplied by a small battery.

(And if you are feeling really frisky right now and want a cheap way to keep all your current air conditioner vents and fans working, but not the motor itself, just cut that wire and clip on leads to a micro switch mounted on the dashboard. Then you can disable the motor itself while having the rest of the system working: you get more power and less engine heating climbing hills, for example. To really have fun, if you have a vehicle with a distributor and coil, mount an identical micro switch beside the one for the air conditioner, and cut and splice into the wire between the distributor and coil. With that switch flipped off, the engine will not start, not even when hot wired, and will drive potential thieves nuts! (I've made both modifications on my motor home, and they work!) If you have a diesel vehicle, there is a wire to the fuel injector motor that operates an electromagnet against a spring: turn off the ignition, the electromagnet shuts off, the spring closes a valve, and the engine stops cold. It is easy to cut that wire and install a micro switch in the same way as between a distributor and coil on a gasoline vehicle, with the same marvelous results. Why give potential thieves any breaks at all?)

Back to steam. Steam is produced by boiling water. Sounds really simple, but an efficient boiler is a bit difficult, as heat must be introduced to as much water surface area as possible. One fairly good steam producing system that can be manufactured at home is to use a sturdy 55 gallon drum and mount it above a wood burning chamber with draft controls. Holes can be drilled or torched into each end using a template, so they line up vertically, identically, and automotive exhaust pipes stuck through each hole, through the barrel completely (out the upper hole), and then welded in place (without water leaks). At least 10 pipes are needed to introduce enough heat to the water to induce boiling temperatures in a reasonable amount of time. The bottom side of the barrel will need a flange welded on for a drain petcock, and to hold the bottom of a glass sight level. A flange on the top side (directly above the lower flange) can hold the top of the sight level. The smallest bung on top can be replaced with a 3/8" reducer for the steam output, and the largest bung replaced with a 3/4" reducer for a standard water heater over pressure pop off valve, to prevent too much steam pressure in the unlikely event you get the water too hot, just for the sake of safety (Exploding steam boilers are not fun to be around.)

In use, a fire is built under the water filled barrel (hence the sight level) and heat rises through the exhaust pipes to heat the water: the water closest to the pipe (and the bottom of the barrel) flashes into steam and rises to the top of the barrel, escapes out the 3/8" pipe to turn the steam engine, and the return line from the air conditioner motor is plumbed to an automotive radiator for cooling (which can be placed in a greenhouse, for example), then the still hot water returned to the barrel for boiling.

I have not built one of these units, but I have examined one in operation -- and they do work! The one I saw in operation was way back in the woods, built by a real, genuine, bearded, fire breathing hermit, and every Saturday he would fire it up. After about 2 hours of boiling, the steam engine would really start pulling, turning a 175 watt truck alternator, which in turn charged 12 huge 2 cell batteries in an old shed. The batteries were wired in series and parallel, producing 12 volts of power with an incredible draw down reserve. Once the steam engine was at full power, he used a different pulley on the jack shaft to grind grain or whatever else he wanted to turn, such as a power saw or hydraulic motor for a log splitter. In his cabin were a 12 volt refrigerator, lights, etc, all taken from an old motor home. All the comforts of home, way back in the boonies, powered by a wood fire every Saturday! That hermit has style!

WARNING:  There are quite serious dangers involved in steam power production. The pressure vessel can explode and scald anyone close.  The old hermit who used the modified barrel mentioned above did not use a pressure vessel, but instead used the barrel because it could not hold much pressure, and therefore if it burst, it would be at a very low pressure.  Others say that such a system is impossible to build...but I have seen it in operation.  There are no guarantees!!!

------------------

 

---