Small Sawmills: Their Equipment, Construction, and Operation

Cover
U.S. Department of Agriculture, 1918 - 68 Seiten

Im Buch

Ausgewählte Seiten

Andere Ausgaben - Alle anzeigen

Häufige Begriffe und Wortgruppen

Beliebte Passagen

Seite 57 - To find the pressure in pounds per square inch of a column of water, multiply the height of the column in feet by .434. Approximately, we say that every foot elevation is equal to % Ib. pressure per square inch ; this allows for ordinary friction. To find the diameter of a pump cylinder...
Seite 19 - Raise the safety valves cautiously and frequently, as they are liable to become fast In their seats and useless for the purpose intended. 10.
Seite 62 - Circular pitch is the distance from the center of one tooth to the center of the next, measured along the pitch line.
Seite 58 - To compute the capacity of pumping engines, multiply the area of water piston, in inches, by the distance it travels, in inches, in a given time. Deduct 3 per cent for slip and rod displacement. The product divided by 231 gives the number of gallons in time named. To find the...
Seite 61 - Constant of an engine is found by multiplying the area of the piston in square inches by the speed of the piston in feet per minute and dividing the product by 33,000.
Seite 57 - To find the velocity in feet per minute necessary to discharge a given volume of water or liquid in a given time, multiply the number of cubic feet of water by 144, and divide the product by the area of the pipe in inches.
Seite 24 - This distance should be such as to allow of a gentle sag to the belt when in motion. A general rule may be stated thus : Where narrow belts are to be run over small pulleys, 15 feet is a good average, the belt having a sag of i£ to 2 inches.
Seite 58 - Steam is steam containing free moisture in the form of spray or mist, and has the same temperature as dry saturated steam of the same pressure. Saturated Steam is steam in its normal state, that is, steam whose temperature is that due to its pressure; by which is meant steam at the same temperature as that of the water from which it was generated and upon which it rests. Superheated Steam is steam at a temperature above that due to its pressure after leaving the liquid from which it is generated.
Seite 63 - ... the saw line after a cut has been made. The carriage frame is mounted on trucks which travel on tracks, the carriage being actuated by a steam feed, a cable, or a rack-and-pinion device, which propels it back and forth past the head-saw.
Seite 24 - ... 2£ to 4 inches. For main belts working on very large pulleys, the distance should be 25 to 30 feet, the belts working well with a sag of 4 to 5 inches.

Bibliografische Informationen