[Gasification] Benefits of boosting compression ratio with producer gas

[Toby Seiler]

Sorry Tom, I didn't ask the question correctly (or I may be off in left field).  This comes from some time spent in a place called Flow Dynamics Laboratory where inlet design of blowers was being tested.  My application was sawdust material moving.  Dan, the owner, explained how pressure was much more effective than vacuum for moving mass.  He explained that drag in a vacuum is hard to overcome, while pressure fills the space with molecules and can push materials great distances.  
 
When talking engines, for example on my 74 Ford f600, I watch the vacuum gage and see that it is around 18-22" of vacuum, warmed up 1200 rpm or so (driving hydraulic pump).  So what goes to the cylinders is not atmospheric pressure, it is around half, perhaps less.  
 
I'm trying to understand how engine efficiency is related to both air and gas pressure and density.  If producer gas is operating with 18/1 in a normally aspirated engine, due to high octane, how will the ratio be affected if one has positive pressure at one or two pounds?  
 
Seemingly this would involve air flow across an orifice, similar to a butterfly valve (throttle), but I am at a loss for a good start point.  
 
Given a large quantity of air and gas to make comparable power (not large derated), the flow of air/gas in a large displacement engine would seem to be a much more critical factor than just saying the cylinder is seeing atmosphere pressure and forgetting the drag that manifolds, throttle valves and pulling gas from a gasifier creates (in a suction system).  I can hardly see a direct linear relationship. 
 
My work is a low pressure system, so this is not an academic or theoretical discussion that I will never act on and I'm at a point of determining engine for a CHP and what internal modifications to plan, if any.   I have several engines, a 345 International, a 460 Ford, a Cumins 5.7 (with needed repair), a 7.3 International (in a ford truck also needing repair).  
 
Sorry if this is confusing or not cogent.  I'm trying.
 
Toby
seilertechco 
 
 
 
 


      
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