REGARDING INJECTORS

Common injector

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312 E. Franklin St. Crawfordsville, Indiana 47933

In response to the questions of Mr. Floyd Cook and Mr. George Pohl regarding injectors: I take pen in hand to pass information from my long association (3 years) with steam engines.

According to International Correspondence Schools (ICS) textbook of 1902 and Hawkins Maxims and Instructions for the Boiler Room of 1899, the following takes place.....

When steam is admitted into the injector, it passes the suction jet and picks up water from the supply line. The water is entrained (mixed) with the steam and a certain amount of condensation takes place. (The steam has a velocity of approximately 2500 feet per second as it enters the injector.) During the passage of the steam and water mixture through the injector the steam is condensing and until the water/steam proportion becomes correct the mixture passes out the overflow. During the condensation process, the bulk or volume of the steam may be reduced as much as 1000 times, however its velocity remains practically undiminished. While combining with the supply water, this velocity is imparted to the water. This velocity and resulting energy obtained from the steam is sufficient to cause the water to flow into the boiler.

As you can see the injector operates on a variety of laws of physics. Steam pressure, condensation and jet propulsion.

While injectors are extremely simple and will work under adverse conditions, there are certain times that they will not perform the desired function and can prove most aggravating. The water temperature cannot be too high or it will boil under the reduced pressure during pickup and cause the injector to 'slobber'. Should the overflow check valve become stuck or the seat leak, air will enter the injector and disrupt the operation. In case of too high steam pressure, complete condensation cannot take place, especially with warm water. In the case of injectors which operate with exhaust steam (not commonly used due to the presence of lubricating oil) sometimes the steam is too cold to cause the proper amount of condensation and the injector fails to function.

I have enclosed a sketch showing the basic parts of a common injector (a Penberthy).

While on a western trip last summer, my wife and I visited the Hall of Fame, which I wish every one could visit. I was so pleased to see Mr. Cortelyou's donation. At this museum there are a few threshing machines and traction engines, a fine display of early farm machinery and implements, plus a large collection of home and farm antiques.

We stopped at Dorrance, Kansas to see Elmo Mahoney. Mr. and Mrs. Mahoney were very gracious. He showed us his big Avery outfit which had been owned and operated by his dad, Mr. Tom Mahoney, a well known Kansas thresherman. The big 42'-70' separator is now retired, and resting comfortably in a machine shed. It was the last one built and was made especially for Mr. Tom Mahoney according to his plans and specifications. Pictures of this outfit can be seen in the Jan.-Feb. 1966 Issue of the I .M .A. magazine.

Even though our big steam rig and locomotive days are history we can enjoy being active and enthusiastic about our hobby.

Mr. R. C. Wilkerson's letter in the recent Nov.-Dec. issue of I .M .A. magazine told how his dad ran a sawmill with two engines on a line shaft. I can recall a sawmill operator in 1908 who did exactly the same thing--a Mr. Stevens set his two traction engines side by side. One was a 15 Horse Case, bit. 1904. The other was a 13H, Geiser, built in the 90's. This gave his 28 H .P. on a double saw Geiser mill 'and worked fine.' This was here in Mercer County, and the outfit was on our farm. Yes, Mr. Wilkerson, like many others, 'I still love steam engines.'

Thanks to those who identified the Robert Bell engine.