Just to let you know at 12:55 27-02-2008 we sat through the earthquake in Leeds West Yorkshire. The entire house was vibrating and my sofa moved forwards, we knew within a couple of seconds what was going on.
We noted it lasted around 15 seconds!
Just to let you know at 12:55 27-02-2008 we sat through the earthquake in Leeds West Yorkshire. The entire house was vibrating and my sofa moved forwards, we knew within a couple of seconds what was going on.
We noted it lasted around 15 seconds!
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They will need capacitors to work. The newer metals used in some motors are more efficient as far as the hysteresis losses go. That means a few of them don't have the
'fault' of having residual magnetism. What's good for a motor is, in
this case, bad for the generator start-up.
I think where the confusion is starting may be from the planned usage.
In a grid tied IMAG (Induction motor generator) the thing will spin like
a motor until you apply motive power to it. It has to spin a bit faster
than the synchronous speed in order to generate. This setup is pretty
much fool proof. You start it as a normal motor and should the grid go
down, it stops generating. Note that you HAVE to start it as an electric
motor FIRST, from the line.
Now, IF we don't want this IMAG running constantly, there has to be a
mechanism to ensure that it will be running in phase with the power
lines when we connect. It can get expensive, but a cheap method involves
the use of a light bulb placed in parallel with a breaker which is in
the line going to the grid.
The operation starts by bringing the motor up to speed with your prime
mover. When the generated power is in sync with the line, the light bulb
will go out and the breaker can be closed. The rotor is now locked to
the line frequency.
That last setup requires the capacitors you speak of in order to start
generation from the residual magnetism. It is an isolated system at
start up and needs its own reactive power.
For line connected, grid start motors:
The simplest inter-tie allowed is with an induction generator which is
excited by the grid, so *no* problems with synchronization. The
generator is turned somewhat faster than synchronous speed so there is
positive slip and generates power into the grid as long as the grid is
powered. This power grid is an "infinite buss" and gives all the kVAr
required to magnetize the generator and accepts all the kVA the
generator can produce.
So far so good! When the power goes off, then the induction generator
unloads and must be protected from overspeed etc, and even though there
may be fuel available and the engine could be run, it cannot generate
backup power.
http://www.smokstak.com/forum/showthread.php?t=20046
Grid Connection Required
On the page about the permanent magnet synchronous generator we showed
that it could run as a generator without connection to the public grid.
An asynchronous generator is different, because it requires the stator
to be magnetized from the grid before it works.
*You can run an asynchronous generator in a stand alone system, however,
if it is provided with capacitors which supply the necessary
magnetization current.* It also requires that there be some remanence in
the rotor iron, i.e. some leftover magnetism when you start the turbine.
Otherwise you will need a battery and power electronics, or a small
diesel generator to start the system).
http://www.newenergy.org.cn/english/guide/async.htm
The Battery Charge Process
Introduction
Batteries are complex mechanisms that can even fool the experts at
times, so it comes as no surprise that non-technical people have a
hard time understanding the charge process. Ask a typical crowd of
battery users when their batteries are full charged and at least ten
answers will surface.
In both Living on 12 Volts with Ample Power, and Wiring 12 Volts for
Ample Power the authors explain that a battery is fully charged when
the voltage is about 14.4 Volts and current through the battery has
declined to less than 2% of the capacity of the battery in Amp-
hours ...2 Amps for a 100 Ah battery.
That information is substantially correct, however, a more intuitive
feel for the charge process is necessary, not only to understand when
the battery is full, but also to know when the battery is not
behaving normally. It is the intent of this application note to
provide enough information about the charge process so that the
average user can judge how well the batteries are charging.
The Bulk Charge Step
When a charge source is first applied to a well discharged battery,
charge current begins to flow, typically at the maximum rate of the
charge source. If a true 40 Amp charger is connected to an 8D battery
which is completely discharged, about 40 Amps of charge current would
flow for some period of time. Because most of the charge is delivered
at the maximum charger rate, the first step of the charge cycle is
called the bulk charge step. NOTE: During the bulk step, battery
voltage will steadily rise.
The Start of the Absorption Step
At the instant battery voltage has risen to the maximum allowable
voltage of the charge source, current through the battery begins to
decline. This simultaneous event of reaching maximum voltage and the
start of current decline marks the beginning of the absorption step.
For instance, if the 40 Amp charger is set to 14.4 Volts, then when
battery voltage has risen to 14.4 Volts, the charger will now hold
the voltage constant. Current through the battery will begin to
decline. NOTE: The charger, (or alternator), is not limiting the
current at this point. The battery is `absorbing' all it can at the
voltage setpoint.
The End of the Absorption Step
The absorption step should continue until current through the battery
declines to about 2% of battery capacity in Amp-hours as mentioned
above. Without knowing what the current is through the battery, you
can't know when it's full. Just because that fancy charger, (or
inverter/charger), has kicked out to float is no sign that the
battery is full ...there is no charger on the market that measures
battery current!
It's a given, then, that you need to measure battery current to know
when the battery is full. With a battery current meter, you can
discover some very interesting details about the charge process. For
instance, you can discover that once the charger voltage limit is
reached, battery current begins to decline. If the current decline is
rapid, either the batteries are nearly full, or they are NO GOOD! If
the current decline is slow, then either the charge source has more
output than the batteries can reasonably absorb, or the batteries are
NO GOOD! Here's where Amp-hour instrumentation is particularly
valuable.
Given enough time at the absorption voltage, charge current will
decline to a steady-state value, that is, a low current that either
stays constant, or declines very little. At the point where charge
current has gone as low as it is going to, then the batteries are
truly full. While 2% of Ah rating is close, good batteries will reach
a steady state current at less than 1% of Ah rating.
The Float Step
Once a battery is full, a lower voltage should be applied that will
maintain the full charge. Depending on the type of battery, (liquid,
gel), and the age of the battery, 13.4 - 13.8 Volts is appropriate as
a float voltage.
Temperature Compensation
The voltage given above are good only at F, (C). For high
temperatures, voltage will be less. It is important to charge
batteries with temperature compensation. To learn more about this
aspect of charging, refer to page 70 in the revised edition of Wiring
12 Volts for Ample Power.
A Very Common Problem
Your batteries are only four months old. You discharge them until
their voltage is less than 11 Volts and then crank up the engine. The
alternator brings up the voltage to 14.4 Volts very quickly, but the
current begins to decline immediately and in a few minutes is down to
a few Amps. You:
*suspect your voltage regulator and immediately call the factory and
ask for a replacement to be sent out; OR
*realize that something has happened to the batteries because the
alternator and regulator are operating as expected.
Conditioning Batteries
How do batteries that are only four months old die? Perhaps they
weren't broken in properly; maybe they sat deeply discharged for a
few days or more; perhaps they were allowed to self-discharge over
the last four months ...there's plenty of ways to murder batteries.
All batteries that refuse to accept a charge are not necessarily
ready for the scrap heap. Often, a deep discharge followed by a slow
charge will recover lost capacity and charge acceptance. For more
information, refer to Wiring 12 Volts for Ample Power.
We did our time as nomads in a couple Winnies. We still have a Tioga
and a Chinook. We raised two welps without death or major crime.
In our experience the real problem with a baby is heat. If you have
good heat you can make do while you deal with the rest.
We have found no small scale solar anywhere near effective for space
heating up here above the 40th parallel. The woman who does will be
the one Bill Gates goes to for a loan.
We have 3 Toyo heaters in our trailer and would strongly advise you
not to use them in the same air space as your child. We use them only
in emergencies. In an emergency we evacuate the child ASAP.
We used to flip an old cast iron skillet over a burner to heat up in
the morning but again that is not good for baby.
If you can put in the fireboard and do a safe job the wood stoves
built for wall tents work great but they are scary as hell. Don't put
one between you and the door.
We have slept in tents with a box of hot rocks and been very
comfortable and safe. Not real eco friendly but if you have a back for
it we recommend it. It works and is safe for baby if hard on Dad.
Don't use river rock.
Our Winnies had combo heater/reefer units made by Electrolux and were
very safe and function-able so you might be willing to pay for the fuel
if you don't want to adapt. There is a small danger to baby but
nothing near Toyo's and the rest.
A propane fridge is an oxymoron as far as we are concerned. We
frequently go over a hundred F.
We use to this day coolers and ice in an adaptation cycle.
If you do the maths you will be able to decide if it is worth it to
you. For us solar powered cold creation is not cost effective at small
scales any where it gets hot.
We used/use the fridge for mouse proof storage.
We have and still use semi daily a "turkey" cooker propane stove. It
boils up a big pot of water in less time than a cup of tea. You will
want more hot water now. We paid $28 for it at a hardware store and a
propane tank gives us baths and wash water for about 40 days. With a
baby probably about 30.
We use the sawdust bucket method from the Humanure guy. We didn't mean
to. We were just using it while we built our composting toilet. It
works so well we just kept using it. It is by far the best way to go.
Diapers will be a problem. Washing them in the woods is no more eco
friendly than composting disposables. You can save a lot of time
composting. We gave up and used disposables and froze them in bags in
the winter and dumpstered them when we went to town. We composted them
and even tried to burn them. There just wasn't an easy way to deal
with it.
Grandpa used to say
"The surest way to get rid of your wife is to move her to the woods".
In our experience if you want to keep sane and married you need to
make sure you have SPARE rain shelter, heat, something hot to drink, a
hot wash up and clean underwear. In that order.
Everything else is extra and negotiable.
Make your man get you a REALLY comfortable chair that rocks and one of
the soft tummy carriers so you can free up your hands.
Make him deal with the diaper disposal.
If he loves you he will buy you a big wash tub and care for baby while
you have a hot soak twice a week.
Get a good tent you can stand in, a tarp big enough to cover the tent,
a 100' nylon cord, a good stout knife, a cot to keep you and baby off
the ground, a cold weather bag and a space blanket. Practice putting
the tent up with baby on your tummy. You need to know you can do it alone.
Get a double burner propane stove and lantern and a case of those
little propane bottles.
Get a half dozen NEW five gallon buckets with proper lids and put
clean dry SPARE underwear and baby clothes/towels/blankets/diapers in.
Fill one with paper plates and disposable forks and the like and
another with instant drinks and tinned food.
Don't leave out stuff, don't cheap out because you think you will
never use it.
Put the stove, lantern, tarp, tent, propane, line, knife and a roll of
trash bags in a big plastic tote box.
This is all EXTRA. You don't use it except in emergencies.
It is a $250 insurance policy for your domestic tranquillity. If you
never need it good on you. If like us you find the woods throw you a
few unexpected parties you will be happier. As in less unhappy.
After all these years we still have our bucket full of plastic forks
and such. We have raided it once or twice. We still have the stove(s)
and lantern and tent. We added an air mattress two years ago. We
switch out the propane canisters every year when we go camping
elsewhere and we have changed out the food but we still keep our
"Spares". We have only had to use the stuff a few times in all these
years but they have made the difference between living in the woods
and visiting.
Air or Steam lift pump video on YouTube. This is used for feeding a steam Babington, using Air, Steam, or even Propane to lift waste vegetable oil to the ball.
http://www.youtube.com/watch?v=1asAWAowbQA
An air lift pump can lift a liquid to a height above the surface of the liquid equal to about 2/3 of the depth at which the air is injected into the bottom of the vertical pipe.
The capacity of the air-lift pump depends largely on the percentage of submergence of the foot piece; that is, the greater the submergence of the foot piece below the water level in the discharge pipe, the greater the volume (column) of water the pump can deliver per unit of time. However, the deeper the foot piece is submerged, the greater the compressed air pressure must be to lift the column of water.
http://www.geocities.com/~dmdelaney/air-lift-pumps/Air_lift_pumps.html
In air-lift pump operation, compressed air has to be regulated correctly. The amount of compressed air should be the minimum needed to produce a continuous flow. Too little air results in liquid being discharged in spurts, or not at all. Too much air causes an increase in the volume of discharge but at lower discharge pressure. If air is increased still further, discharge volume begins to decrease
Some details for water pumping..
Sizing the air lift pump
The flowrate through an air lift pump is proportional to the flowrate of the air powering it. The literature reports air lift pump flow rates of 20 to 2,000 gpm and lifts to more than 700 ft.
An empirical calculation attributed to the Ingersoll Rand Co. correlates the flow of air with that of water.
Va = 0.8 Ll/(C log10{(Ls + 34)/34]
Where Va = volume of free air (cu. ft.) needed per gallon of water
Ls = length of the submerged section (ft.)
Ll = length of the lift section (ft.)
C = constant that depends on Ll (see Table 1)
Another relevant variable is the relationship between Ls and Ll. Functional air lift designs exhibit a curious non-linear phenomenon. The ratio of submerged length to total length, Ls/(Ll + Ls), runs about 0.6 when the lift is only around 20 ft., but decreases to about 0.4 when the lift is 500 ft.
The last relevant variable is the air pressure needed to make the device operate. This depends, of course, on the specific gravity of the fluid. The depth that corresponds to one psi is inversely proportional to the specific gravity. For water, one psi corresponds to 2.31 ft. of depth. If one ignores the friction losses in the line, the applicable relationship is:
P = (Ls * sg/2.31)
Where
P = required gas pressure (psig)
sg = specific gravity of the fluid (dimensionless)