This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1918 edition. Excerpt: ...chloride only 19.9 pounds absolute, which is a low pressure and safe to handle and it is obvious that the wear upon the machine will be much less than on those using a high pressure refrigerant. With this extremely low pressure the loss of refrigerant through the stuffing box of the compressor and valve stems will be small while with the high pressure refrigerant it is very great and requires long and heavy stuffing boxes. On account of its low specific heat and the resultant large volumes which must be used to produce the desired refrigerating effect, reciprocating machines become unpractical, at least for use on board ship, and it is necessary to resort to compressors of the rotary type, one of which is shown in Fig. 392, an outline of the entire machine being shown in Fig. 393. These rotary compressors are particularly adapted for use where large volumes at low pressures are to be handled. There are no valves, springs or other small pieces that can drop into the working parts. The compressor consists of a cylinder with suction and discharge ports cast in the walls. A cast iron rotor is mounted on a chrome nickel steel shaft which is located eccentrically in the cylinder, so that a line of contact is formed between the top of the cylinder and the revolving rotor. Four slots are milled radially in the rotor in which slide cast iron blades fitted with half round steel packing strips which form the bearing surface against the cylinder. These blades are held apart by steel spacing pins which pass diametrically through the shaft and are prevented from eroding the blades by steel backing strips. The cylinder is capped at each end with cast iron heads in which are located the roller bearings supporting the shaft. A sight feed lubricant...