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.