Bob O'Neil Air Engine

[Motorcoach1]

   Been doing some more reaserch here. In the  quote [ combination fluid operated engine and compressor ] at the start of the patent.

After doing some reaserch from what Tom has mentiond , due to the fact ' fluid operated ' was in the patent. this shed more light on this engines machenical parts and their funtion.

  Lets start the engine in our minds eye........

First we turn on the start resivore tank [ this is not the eqlizer tank ] . this tank is just for starting the engine. We push the start valve , this turns the airmotor starer at the flywheel. This air motor turns over the engine slowly for say 2 to 4 minutes.

                           Now we ask why so long ?

   When we first start the engine it is all in compressor mode, all 10 compounded cylinders an the 2 pistion cylinders. What happens within the next 2 to 4 minutes is somewhat of a metmorphsis.  As the engine is turning over pressure and vacumes are exchanging placeses. As the tempeture differentals build to the desired levels P & V swap sides and the equlizer valve is in full operation at a high occillation [ as Tom said liqfacation or close to it ] . What is now the 10 cylinders that started in compression swap to vaccume pull and the 2 pistons swap to pressure push.
I belive the center tube connectting the 10 cylinders would be larger to acommadate a high speed venture valve to get the tempatures down even farther than the porting from the cylinders directly.  One other thing happens also is the generator kicks on for the heaters .

[Joe1]

   Been doing some more reaserch here. In the  quote [ combination fluid operated engine and compressor ] at the start of the patent.

After doing some reaserch from what Tom has mentiond , due to the fact ' fluid operated ' was in the patent. this shed more light on this engines machenical parts and their funtion.

The term "fluid" is used in the scientific world to imply fluid dynamics, which is not to imply liquid as in solid-liquid-gas.  It may be that Bob Neal is using the proper scientific use of the word fluid, which implies changing pressures and velocities of a gas.
For an alternate explanation of Bob Neal, see the discussion at:
http://aircaraccess.proboards.com/index.cgi?board=tank&action=display&thread=78
You might find some interesting reading there.

[Tom Booth]

The term "fluid" is used in the scientific world to imply fluid dynamics, which is not to imply liquid as in solid-liquid-gas....

That was my understanding when reading the patent. fluid = gas.

What puzzles me is the inlet valves (on top of the compression cylinders). If the purpose was simply to provide an inlet for air to be compressed, why not just use ordinary check valves as elsewhere? Using strong springs would tend to severely restrict air flow into the compression cylinder which would just put an unnecessary strain on the engine to open such valves. Of course, just how strong the springs may have been is guesswork. The patent lacks detailed specifications.

I tend to very much doubt that liquefaction of air could be achieved in one stroke of a piston in such a manner, but without an actual change of state, the strong valve would just put a strain on the compressor to no end, as far as I can see. If it were possible (change of state to a liquid, or at least a vapor mist), once liquified there would be a tendency to remain liquid, at least long enough for the chamber to be evacuated. That would serve some purpose.

Air can and has been liquified using some rather crude apparatus.  Some early air liquefaction machines look almost like an apple press with just a hand cranked wheel to do the work. I think Lind liquified air continuously and in some volume with just a 3 horsepower engine with only water cooling, though the air was recirculated, compressed and cooled repeatedly.

I have some doubts about it but I think the formation of a MIST of partially liquified air might have been possible with such an engine. At any rate, it seems to be suggested by the construction, given the apparently strong valves used, rather than simple check valves.

What got me thinking along these lines is the reportedly "below freezing" temperature of the air in the tank. Was this engine intended for use in some situation where the ambient temperatures would be so cold ? Possibly, but I hardly think so.

One other thing that puzzles me is the report that he made a small model to take to the patent office. Setting it on the desk of the patent examiner. If this thing required water cooling to operate, how would that have been accomplished at the patent office without a source of water for cooling? Tap water from the sink ?

I have been thinking of a means of testing this idea of running an engine by "pulling a vacuum" using a small model, like a Stirling engine.

I may post something on that in the next day or two.

[Tom Booth]

I thought it might be interesting to compare the Lind Air Liquefying machine with Neal's Air compressor/engine.

There are several apparent similarities or corresponding components. Of course there is an air inlet, a compressor, a water jacket or cooler, a storage tank for the compressed/liquified air, and Lind's machine has an adjustable throttling valve.

And some differences. Lind's machine did not use mechanical expansion. Rather the air was first compressed and cooled and then allowed to expands through the valve into the tank where it then became liquid. Lind's machine also recirculates, re-compresses and cools any air from the tank that fails to liquify in previous cycles.

Neal's engine combines the various elements in one machine rather than having the components separated, Also, the function was different. Lind's object was simply to liquify air whereas Neal's was power production.

We might imagine Lind's machine utilizing the liquified air from the tank to in turn run an engine to run the compressor.

Anyway, here is an illustration of Lind's Machine:

[Tom Booth]

OK here is my idea for a relatively simple way to test this theory that an engine might be able to run (on ambient heat) by "pulling a vacuum". (Along with simple water cooling.)

It may not actually say much about the Neal Compressor or engine itself, but at least it might demonstrate the basic principle.

There are a few different possible variations.

The basic idea though is to use a "throttling valve" to create a partial vacuum for cooling so as to create a temperature difference. The cold produced, theoretically, making it possible for an engine to run on ambient heat.

In this case I'm using a conventional "Low Temperature Differential" Stirling for the sake of simplicity as well as to avoid some of the problems involved with the possibility of building a Neal type engine, besides the cost and complexity of building such an engine, by using a Stirling Engine the cold produced could be used directly, obviating the need for a storage tank and the problem of how to get low pressure air into the tank, the "equalizer" and all that.

Today, a "throttling valve" is less frequently used as it has been found that an expansion turbine is more effective, so there are two versions, one with a valve similar to the one in the Neal Compressor and another where the valve has been replaced by a turbine.

The valve stem is threaded so that the spring tension is adjustable.

Similarly, the turbine has a brake so that resistance can be placed on the turbine. The more pressure applied to the brake, the more the "throttling" effect and the greater the cooling effect. Making these adjustable allows the engine to at least run (hopefully) and then the "throttling" for cooling can be applied gradually to whatever degree the engine might be able to handle.

I'm using a clay pot for the water cooler. It could be filled with ice water, but I think there is a chance that it would provide sufficient cooling with just evaporative cooling.

Also some heat source, like a block of heated metal is shown to get the engine started and provide a temperature differential until some cooling can be effected.

Basically you have a simple LTD Type Stirling Engine sitting on a cooling plate or simple "refrigerator" and, theoretically, if enough cold is produced by "throttling" then the engine could continue running and powering its own cooling system by utilizing ambient heat.

Eventually the heat source (block of metal or "starter") will cool off to ambient temperature or could be removed. The ice would melt and it could be seen if the "throttling" or "pulling a vacuum" provides enough cooling by itself to keep the engine going without these.