Posted by Neon John on March 16, 2009, 4:23 pm
On Mon, 16 Mar 2009 08:45:36 -0500, "William Wixon"
>> The bearings operating in vertical position should last a good time,
>> because they are very large, and the axial load on them is less than
>> 1/10th the maximum recommended value. The bearings are rated for 5000kg
>> radial and 500kg axial load. They are intended for driving the generator
>> with a highly tensioned flat belt.
Not gonna get into an "is too, is not" debate by remote control but
this is simply wrong. I'd love to see a simple ball bearing that size
rated for over half a ton of axial load.
In addition to being an engineer, I also moonlight in an electric
motor repair shop and have for decades. I've learned a few things
about bearings and have seen the disaster that results when motors are
operated vertically without being outfitted with thrust bearings.
A motor usually stops when the bearing fails and the rotor gets out of
alignment enough to trip the protective device (or smokes the stator
if it doesn't have one) but on a generator? Who knows?
This guy obviously has a lot of money to spend so maybe trashing a
generator every so often isn't a big deal but the work to replace it
is, at least to me. All he needs to do is fit a thrust bearing on the
bottom and problem solved.
>>
>> It makes no sense to control the water instead of using the dump load
>> method. The motorized valves would be expensive and slow, and the water is
>> free and available. Fast valves anyway are not usable, because of
>> waterhammer.
I agree but not because of water hammer. simple KISS. Water hammer is
handled with a surge column - no big deal.
I don't want to come off sounding negative because I AM impressed with
his whole setup. It's just that it could be improved with only a tiny
additional cost and effort.
John
Posted by z on March 17, 2009, 3:28 am
> On Mon, 16 Mar 2009 08:45:36 -0500, "William Wixon"
>
>>> The bearings operating in vertical position should last a good time,
>>> because they are very large, and the axial load on them is less than
>>> 1/10th the maximum recommended value. The bearings are rated for
>>> 5000kg radial and 500kg axial load. They are intended for driving
>>> the generator with a highly tensioned flat belt.
>
> Not gonna get into an "is too, is not" debate by remote control but
> this is simply wrong. I'd love to see a simple ball bearing that size
> rated for over half a ton of axial load.
>
> In addition to being an engineer, I also moonlight in an electric
> motor repair shop and have for decades. I've learned a few things
> about bearings and have seen the disaster that results when motors are
> operated vertically without being outfitted with thrust bearings.
>
> A motor usually stops when the bearing fails and the rotor gets out of
> alignment enough to trip the protective device (or smokes the stator
> if it doesn't have one) but on a generator? Who knows?
>
> This guy obviously has a lot of money to spend so maybe trashing a
> generator every so often isn't a big deal but the work to replace it
> is, at least to me. All he needs to do is fit a thrust bearing on the
> bottom and problem solved.
>
>>>
>>> It makes no sense to control the water instead of using the dump
>>> load method. The motorized valves would be expensive and slow, and
>>> the water is free and available. Fast valves anyway are not usable,
>>> because of waterhammer.
>
> I agree but not because of water hammer. simple KISS. Water hammer is
> handled with a surge column - no big deal.
>
> I don't want to come off sounding negative because I AM impressed with
> his whole setup.
Yeah the scale of the project and work involved is staggering.. and
impressive.
Posted by Gordon on March 16, 2009, 7:22 pm
>> It makes no sense to control the water instead of using the dump load
>> method. The motorized valves would be expensive and slow, and the
>> water is free and available. Fast valves anyway are not usable,
>> because of waterhammer.
>>
>> I definitely don't have to walk to the turbine site several times a
>> day. Actually, it's more like once a month. Still, remote control
>> would be nice, and is planned for the future.
Being a frugal Yankee, what gets my hackels up about this system
is the thought of all that power dumped for the sake of regulation.
If it were me (and I know it's not), I would have run a 2nd line up
to the house and hooked it to a water heater or electric baseboard
heater. Then, the load dump controler would act more as a load shed
controler. I realise that this would not be simple, since the
dump load and the 2nd line would like to see a significant amount of
power running through them.
At least one remote control valve would be nice. That would allow
the system to be put into lower power operation (or kick it into
higher power opperation) when usage demands it.
Posted by William Wixon on March 17, 2009, 3:53 am
>>> It makes no sense to control the water instead of using the dump load
>>> method. The motorized valves would be expensive and slow, and the
>>> water is free and available. Fast valves anyway are not usable,
>>> because of waterhammer.
>>>
>>> I definitely don't have to walk to the turbine site several times a
>>> day. Actually, it's more like once a month. Still, remote control
>>> would be nice, and is planned for the future.
> Being a frugal Yankee, what gets my hackels up about this system
> is the thought of all that power dumped for the sake of regulation.
> If it were me (and I know it's not), I would have run a 2nd line up
> to the house and hooked it to a water heater or electric baseboard
> heater. Then, the load dump controler would act more as a load shed
> controler. I realise that this would not be simple, since the
> dump load and the 2nd line would like to see a significant amount of
> power running through them.
> At least one remote control valve would be nice. That would allow
> the system to be put into lower power operation (or kick it into
> higher power opperation) when usage demands it.
i'd imagine he'll make improvements as time goes by, he's up to his ass in
alligators right now. i thought it was a helluva start.
b.w.
Posted by Gordon on March 17, 2009, 10:59 pm
>
>>
>
> i'd imagine he'll make improvements as time goes by, he's up to his
> ass in alligators right now. i thought it was a helluva start.
>
> b.w.
>
>
>
I agree, it's impressive. Certianly with a project of this
magnitude, you just try to get it running as a start. Then
you look for improvments as you go along. My nitpicking was
just that.
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>> because they are very large, and the axial load on them is less than
>> 1/10th the maximum recommended value. The bearings are rated for 5000kg
>> radial and 500kg axial load. They are intended for driving the generator
>> with a highly tensioned flat belt.