Historic Corliss Steam Engine right here in York, Pennsylvania; Part 2
After my presentation on the First 60-Years of York Manufacturing Company and York Ice Machinery Corporation at the Agricultural and Industrial Museum, as a Second Saturday Program, the huge 1904 A-Frame Ammonia Compressor was demonstrated. Questions arose, that I’m answering in greater detail via YorksPast. Related posts include:
- Free Talk on Predecessors of York International Corporation at Agricultural & Industrial Museum on November 9th, 2013—Contains INDEX of Related Posts
- Steve Jobs & Apple Computer connections to YORK
- Historic Corliss Steam Engine right here in York, Pennsylvania; Part 1, Steam Flow
- Grantley Gals assemble Yorkco Compressors in 1950
- York Manufacturing Company employees and A-Frame Compressor
A question arose about the type of steam engine and the flow of steam. The flow of steam was illustrated and described in my post yesterday. A 1901 York Manufacturing Company Catalog contains a nice cross section drawing of the Corliss Steam Engine powering a YORK Vertical A-Frame Ammonia Compressor. I’ve added notations to this drawing to better illustrate the description of the steam engine operation.
In researching the Corliss Steam Engine, I examined several stationary steam engine books, however my primary reference is Nehemiah Hawkins’ 1904 book New Catechism of the Steam Engine. Google Books also provided access to the 1921 book Audels Engineers and Mechanics Guide 2 by Frank D. Graham; it contained two relevant illustrations, which I’ve used.
Corliss Steam Engines were widely used to power industrial America into the early 1900s, however they were rapidly replaced with the advent of electric motors. As for the Cross-Compound Corliss Steam Engines found on the YORK A-Frame Ammonia Compressor, few of this type and size still exist.
The Corliss Steam Engine is named for George Corliss. George was issued U. S. Patent No. 6162 on March 10, 1849 for a steam engine with a unique arrangement of steam admission and steam exhaust valves. His valve arrangement and control resulted in superior efficiency, smooth running speed and automatic response to changes in load.
The Cross-Compound Corliss Steam Engine on the YORK A-Frame Ammonia Compressor contains a high-pressure cylinder and a low-pressure cylinder. The operation of the Corliss Steam Engine is the same, be it on high-pressure or low-pressure steam. The only difference, within the casting of the low-pressure cylinder is an internal passage taking the low-pressure steam from a bottom connection at the shaft-seal end, up to the cylindrical steam admission valves within the topside.
Valve Operation in a Corliss Steam Engine
A Corliss Steam Engine utilizes four cylindrical steam valves, two at each end of the cylinder. As indicated in the illustration at the beginning of this post, one pair control steam admission on the topside of the cylinder, while the other pair control steam exhaust at the bottom side of the cylinder.
The hot steam admission ports, on the topside, and cooler steam exhaust posts, on the bottom side, are far apart in the Corliss Steam Engine; thus reducing thermal losses. This photo shows typical cylindrical valves used in Corliss Steam Engines.
Outside linkages control the rotation of the cylindrical valves; independently varying the period of steam admission during each stroke of the piston. This greatly improved the efficiency of the Corliss Steam Engine versus previous steam engines that were controlled by opening or closing a throttle valve located between the boiler and the steam engine.
Looking at the illustration at the beginning of this post, one sees that the upper right cylindrical steam admission valve is rotated to open the port; allowing high-pressure steam to enter the cylinder on the right side of the piston, causing the piston to move to the left. Likewise the lower left cylindrical steam exhaust valve is rotated to allow the expanded, low-pressure steam to the left of the piston to be exhausted.
The external Corliss cylindrical steam valve rotation-control-linkages, on the side of the engine, are designed to automatically and virtually instantaneously control the point of steam cut-off to maintain engine speed as load is removed from or added to the steam engine. This is done by variations in power demand being sensed by the governor, which automatically adjusts the linkages accordingly.
This illustration provides the names of major part on Corliss Steam Engines. The illustration also shows the complexity of the external Corliss cylindrical steam valve rotation-control-linkages.
For maximum efficiency and precision speed control, the cylindrical steam admission valves are designed to close quickly and very precisely. To minimize the shock to these linkages and mechanisms, use of air-filled dash-pots provide a cushion to these parts.
This photo shows the installation of the Cross-Compound Corliss Steam Engine on the YORK Vertical A-Frame Ammonia Compressor. The high-pressure side of the steam engine is closest to the viewer in the lower right of this photo.
