108 Garfield Avenue, Madison, New Jersey 07940.
There is a mail slot in my door and through it pass varied
pieces of mail. Some are addressed to Occupant and some to Current
Resident. I don’t know either of these, but they do get
interesting mail. One day my dachshund announced the arrival of our
mail personours is a lady carrier. There among the usual bills and
all was my copy of McGraw Hill’s prestigious Electrical World.
In it I noticed an advertisement for the Skinner Universal Uniflow
engine. It seems the reciprocating steam engine is more than just
another item in an industrial museum.
Although Heron of Alexandria, or Hero, the Egyptian
mathematician, is credited with inventing the reaction steam
turbine, it took the simple reciprocating engine to turn the world
around in an industrial revolution. The wheels of industry were
driven by the steam engine for a hundred years before the electric
motor took over. This electrical work horse of industry is so
complete in its victory that we forget that there are still work
places that depend upon the steam engine and it would seem that
they continue to be manufactured.
These facts have suggested that perhaps in our changing world
there again might be a future for the faithful, reliable and simple
steam engine. With this in mind I began the search to find where
they were in active productive use today. At the same time a brief
look was taken at their future potential.
One of the first places that I came across the continuing use of
the steam engine was at the B. F. Clyde Cider Mill in Old Mystic,
Connecticut. (IMA Nov. 1979). Here, Jack Bucklyn has installed an
Ames Iron Works 15 horsepower engine to power the line shaft
supplying power to various parts of the mill. It is an 8′ by
8′ engine with the governor set at about 220 rpm.
Now, in a way, this is almost an action museum in that it is
operational only during the fall season. On the other hand, it is a
profit making enterprise in which the use of steam for power is in
direct contrast to otherwise using electric motors.
When the Clyde Mill was built in 1881 it was powered with steam.
And, it ran by steam until around 1921 when the boiler and engine ,
were replaced with a gasoline engine. When the grandson of the
original owner took over in 1946 he vowed to return the family
business to steam. It took 20 years to find just the right
equipment to fulfill the dream. Like phoenix, the bird of
mythology, the steam power for the mill arose from the financial
ashes of a New England laundry that had also been operated by steam
power until it closed its doors. Now, in the fall of the year,
thousands of bushels of ripe red apples are turned into delicious
sweet cider as we use the beginnings of a resurgence of the
reciprocating steam engine in industry.
Incidently, Ames Iron Works, builders of this engine, was taken
over by the Skinner Engine Company. A December 1901 copy of POWER
magazine shows Ames of Oswego, New York, in competition with
Skinner of whom we will have more to say later.
Let us think for just a few moments upon just what the
circumstances might be that would return the steam engine to its
bygone glory. I don’t want to get too technical by writing down
a great many formulas and terms, but we do need to look at the
various parts of the problem. So bear with me while I write just
one formula, first in words then in symbols, and we will simply
‘talk’ our way through it to get an understanding of the
various facets of the problem.
15 horsepower VIM model 8′ x 8′ engine built by Ames
Iron Works now powers the B. F. Clyde Cider Mill. The engine has
been completely restored even to the original pin-stripe
design.
Jack Bucklyn, owner-chief operator-mechanic, opens the drip
oilers preparatory to starting up for another day at the B. F.
Clyde Cider Mill.
Total energy cost = investment cost + fuel + operating cost /kwh
= 1 x Fc / 87.6 Fs + hC(10)-6 +
LOST It looks complicated, but it isn’t. Our beloved steam
engine must compete with the electric motor and the electric
motor’s ‘fuel’ is kilowatt-hours whose cost for this we
can assume, say 7/Fwh. We could have written this as cents per
horsepower-hour, but let us keep it the way that it is.
What this says is that if we wish to install a steam engine and
a boiler to run our shop or our sawmill, we must invest some money,
‘I.’ In this formula ‘I’ is a unit cost or dollars
per kw or even dollars per horsepower. So we could figure out how
much it would cost to set up a boiler and steam engine and divide
by the horsepower. In modern day electric companies this runs
around $300 per kw. Today, someone going this route would probably
have to find a second hand outfit to compete unless later on we
find other factors that might be more significant. Fc is the factor
that contains interest rate that has to be paid on the borrowed
money to build the installation plus a factor to pay back the
borrowed money. With 10% interest rates and a ten year estimated
life that would make Fc = 20% which is about where the power
companies are today. Fs is called ‘plant factor’ and it is
the figure that shows how much the plant operated. For example, a
plant that runs on a 40-hour week, 52 weeks per year this would be
40 times 52 divided by 8760 hours per year equals 24% if it ran
‘full out.’ Most power companies have system load factors
around 60%. From this one can see that the investment in the
venture is going to be very important. Most of the plants that I
studied in researching this article fell into two categories.
First, they had purchased second hand equipment at junk value, or
were running a plant that had been built way back in the 20s and
30s and was therefore, fully paid forfully amortized. Those that
were being built new took a different approach.
W. W. Babcock Company plant at Bath, New York is a fine example
of the use of waste wood as fuel. Note the duct work leading from
the manufacturing area to the cyclone separator on the boiler house
roof. That squirrel tail of steam tells us that the steam engine is
at work.
We can best explore them by looking at the term ‘hC
(10)’6’. The term ‘h’ is called ‘heat rate’
or Btu per kilowatt-hour. Power companies run around 11,000
Btu/kwh. A reciprocating engine that operates at 100 pounds
pressure and exhausts to atmosphere uses about 35 pounds of steam
per horsepower-hour (47 # /kwh) or, from the steam tables, this is
55,900 Btu/kwh. If we had to go out and buy fuel for such an
installation, it would be at a great disadvantage compared to an
electric motor run from the local power company. But, before we
abandon the project let’s look at the ‘C’ term. It is
fuel cost in cents per million Btu’s. Here is the basis for one
of the categories that can win free fuel. Who has free fuel? A
sawmill or a wood working mill has plenty of sawdust and chips to
provide the fuel to run the plant, for example. A sugar mill has
bagasse from the crushed cane. Except for some handling cost the
‘hC’ term is zero in these instances. We can put the
handling cost in our ‘operating cost’ or the LOST term
which means labor, operating supplies and taxes.
A July, 1949 letter from the Skinner works tells us that,
‘This is a 14 x 15 left-hand, center-crank, single valve
automatic horizontal steam-tight valve counter flow engine, shipped
from our works in March, 1924.’ It is rated at 125 HP for 100
pound throttle and 2 pound exhaust.
Carl Irwin’s old sawdust fired boiler and Skinner engine
(see IMA January 1981 ‘A Specialized Sawmill’) are no
longer operating in his Harrison, Arkansas, mill but there are
others. One is the W. W. Babcock Company of Bath, New York. This
plant was first organized in the 1890s to make churns under the
name of the Jackson Churn Company. When churns were no longer being
sold they converted over to the manufacture of wooden ladders under
the Babcock name. Today the original Skinner 14′ by 15′
automatic engine driving a General Electric 80 KW generator
installed in 1924 is still operating and supplying about 60% of the
plant’s power requirements. In recent times they have been
required to install fly ash facilities in the chimney, but
otherwise it is the original plant and still running just like a
fine Swiss watch. One of their local lumber suppliers is the
Schuchardt Sawmill. This mill is powered by internal combustion
engines.
High fuel costs were affecting the sawmill’s profit margin.
Ed Schuchardtan IMA reader decided to do something about it. He
purchased a used Skinner 14′ by 15′ engine that had been in
a Bingham-ton plant and had been idle for years. This is just
another example of how an almost forgotten steam engine can again
compete. The Skinner Engine Company, 337 West 12th Street, Erie,
Pennsylvania 16512 is still very much in business and parts for
these old engines are still available. They have never gone out of
the business of manufacturing the reciprocating engine.
Conversations with the Skinner people reveal that they are again
shipping engines up to 3000 horsepower to furniture and woodworking
plants.
Actually, they have a full line of engines. There is a series of
single cylinder engines ranging from an 8.9 HP (4′ stroke) to a
92 HP (10′ stroke) engine. From there they go into the
‘uniflow’ line and at 300 HP begin the multiple cylinder
engines that range up to 3000 horsepower. These larger engines are
built for 300 pounds pressure and can operate into a 26′
vacuum. Such an engine will develop its rating while using only 16
pounds of steam per horsepower-hour.
Let us stay with our ‘hC’ (10)’6′ and examine
the other possible winning category. We just saw that the economy
of the steam engine at low pressure and exhausting to the
atmosphere used five times as much fuel heat as a modern power
plant. What we need is some way of ‘writing off’ this high
heat consumption. In the first place, we are starting with a lot of
heat in the steam but we are not taking much heat out of the steam.
Most of the heat is going out with the exhaust. What we need is
someone to charge with the exhaust. That is what happens in a
process industry application. This principle is older than any of
my readers. But, today it has a new ‘buzz word’ name:
co-generation.
14′ x 15′ Skinner engine rated at 125 HP on 100 pound
pressure steam exhausting to atmosphere being installed in the
Schuchardt Saw Mill in Steuben County, New York.
We can go back to our B. F. Clyde cider mill to make up a
hypothetical example. Let us suppose that they want to extend their
business. They also have a hit-and-miss engine grinding cornmeal.
Suppose we say that they want to make a New England special chowder
by cooking some of the cornmeal along with some local clams. The
steam exhausted from the cider mill engine is going to waste but it
could be run to a steam kettle. The otherwise waste steam would
then be charged to the chowder operation and the cider operation
would be run on almost ‘free power.’ As it turns out, in
most co-generation schemes it is the total picture that is studied
but because we have reduced our total fuel consumption by utilizing
otherwise wasted steam heat we have a total plant that is economic.
There are many more examples that could be cited. A school might
have a steam engine generator for the school’s power
requirement while the exhaust steam was used to heat the building.
When natural gas was real cheap there were several of those
‘total energy packages’ built using gas turbines and waste
heat boilers. A gas turbine (aircraft jet engine) can only use very
clean fuel, so today these installations are suffering from the
high cost of gas. Fortunately, a boiler can handle anything that is
burnable. In my oil refinery engineering days we used to say,
‘If it’s pumpable and burnable send it to the
boilerhouse.’ Sometimes I think the process people sent us a
50-50 mixture of asbestos and water!
This type of analysis can be applied to diesel power or a gas
engine. Suitable figures for investment, fuel and operating costs
can be worked out. The prime mover system that gives the lowest
‘total energy cost’ is to be preferred. For a diesel engine
case the ‘h’ term is about 10,000 Btu/kwh. The ‘C’
term for diesel fuel at $1 per gallon is 714 cents per million Btu.
In case you have forgotten, (10)6 means divide by 1,000,000.
Maybe at this point we can pull this whole thing together and
draw some conclusions as to the likelihood of a return of the steam
engine. We have the three possibilities and these can be in
multiple combinations. First there is the ‘tourist
attraction’ for lack of a better term. Then there is the
availability of free fuel. And last, there is the possibility of
co-generation. Being realistic about the whole subject, it is the
latter two that have the best possibility of economic viability and
they can be evaluated quite easily. To give you a feeling for the
numbers, we have about 400 million kilowatts of power load in this
country today. Of this, it is estimated that there is about 20
million kw in co-generation installations. Up to now this has been
the realm of the steam turbine whose exhaust is not contaminated
with steam cylinder oil that creates problems when the condensate
is returned to the boiler. There is still, however, a place for the
familiar reciprocating steam engine and there should be a modest
future for it. The present day management of the Skinner Engine
Company feel that way else they would not have given it the current
attention.
The question, ‘Can steam come back?’, is very
interesting to us. We asked Carl Lathrop to pose the question in an
article. Your response will be appreciated.
