[Gasification] Two Engines One Gasifier

[Doug Williams]

On Thu, 2 Apr 2015 08:35:08 +0200
"Rex Zietsman" <rex at whitfieldfarm.co.za> wrote:


Hi Rex,
Comments in the text.

> Thanks Doug. I was imagining the challenge of trying to start the two
> engines including the gas distribution but had not given the harmonics a
> thought at all. Good point. Really where I am coming from is to have a
> common generator. The challenge of getting two generators to run in sync is
> fine on the MW level but a huge challenge down at small scale. As it is,
> speed control is already somewhat of an art as the speed is a function of
> load on the generator and a change in speed has an effect on the load of the
> gasifier where the gas CV changes until the new equilibrium is established.

Because you are making something different, away from the tried and
true, I suggest the first thing on the main shaft would be a heavy
fabricated flywheel to smooth load changes. then on the engines, either
mechanical or electronic governors. Unless they are running
electronics, the slight variations of frequency should not be any
bother. I have used American Pearce mechanical governors in the past
and still have a couple of new ones still in the workshop.

> Just not as simple as adjusting the throttle as one would with
> petrol/diesel. 

I agree, and the governor is important if generating power. There are
two choices, one for rough mechanical RPM and the other for rapid
response power generation.
> 
> The clutch you mention: I am assuming that you would put a stripped down
> gearbox on the end of the motor and use a normal car clutch.

This is the most basic way and the clutch plates have a long life in
that role.


> If there is a
> simpler method, I would most welcome it. 

Well you might explore the availability of marine conversion clutch
kits, which used to be quite popular for DIY boat engines on the
Internet

>We frequently want to be able to
> offer a system that can both drive a generator or a mechanical devices such
> as a maize mill. A belt drive clutch would allow us to choose run the
> generator all the time and to pull in the maize mill when required. Do you
> know of any system that has this?

I would guess that India/Thailand might be a good place to look as they
use a lot of belt driven machinery. We were never asked to supply
anything with these features, so have no drawings to copy.

 Possibly I could look at an electric
> clutch similar to that used with air conditioners. Any advice would be
> appreciated.

Not sure about an electric clutch for power generation, but it depends
on how much H.P. it can take.

See what you can find and let me take a look for a second opinion.

Doug Williams,
Fluidyne.