This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
As already stated, when exhaust steam is used for heating purposes, it must first be passed through some form of separator for removing the oil. This is usually effected by introducing a series of baffling plates in the path of the steam; the particles of oil striking these are stopped and thus separated from the steam. The oil drops into a receiver provided for this purpose and is discharged through a trap to the sewer.
In the separator, or extractor, shown in Fig. 54, the separation is accomplished by a series of plates placed in a vertical position in the body of the separator through which the steam must pass. These plates consist of upright hollow columns, with openings at regular intervals for the admission of water and oil, which drains downward to the receiver below. The steam takes a zig-zag course and all of it comes in contact with the intercepting plates, which insures a thorough separation of the oil and other solid matter from the steam. Another form, shown in Fig. 55, gives excellent results and has the advantage of providing an equalizing chamber for overcoming, to some extent, the unequal pressure due to the varying load on the engine. It consists of a tank or receiver about 4 feet in diameter, with heavy boiler iron heads slightly crowned to give stiffness. Through the center is a layer of excelsior (wooden shavings of long fibre) about 12 inches in thickness, supported on an iron grating, with a similar grating laid over the top to hold it in place. The steam enters the space below the excelsior and passes upward, as shown by the arrows. The oil is caught by the excelsior which can be renewed from time to time as it becomes saturated. The oil and water which fall to the bottom of the receiver are carried off through a trap. Live steam may be admitted through a reducing valve for supplementing the exhaust when necessary.