Niagara Falls 100.000-Hp. Development

 12] Niagara Falls 100,000 Hp. Development ernor or to the hand-control system. The plunger valves are located in a common casing with the main governor valve, which is located directly below the actuator, and the same casing supports a lower guide bearing for the governor spindle. All of the valves for shifting from governor to hand control and back again are controlled by a single lever mounted on the governor stand on the gallery. By a single throw of this lever a special control cock is operated which admits pressure to the plungers of the various John- son valves and properly shifts the pressure and return connections from governor to hand control or vice versa. By this system, failure of the operators to manipulate the valves in proper sequence is avoided, thus avoiding loss of control of the unit between the time of its being taken off the governor and put on hand control. The entire operation can be carried out very quickly, which is frequently a matter of impor- tance in station operation, and all loss of time required to open and close the series of valves by hand is avoided. The separate hand control provided in addition to the governor contains separate valves and restoring mechanism by which the turbine gates can be operated through the pressure system, the gates being auto- matically maintained in any position corresponding to the setting of the hand wheel. By this means the unit can be operated on hand control with the governor and all of its valves thrown out of operation and made available for inspection and repair. A clutch is pro- vided by which the governor head may be put out of operation without shutting down the unit so that all parts of the centrifugal mechanism can be made accessible. The centrifugal governor head is extremely powerful and is not influenced by slight changes of friction of the governor parts or other variation of conditions. Among the members of the Cramp company’s organi- zation who have been responsible for the design of this turbine installation may be mentioned: H. Birchard Taylor, vice-president;John Overn, Jr., manager, I. P. Morris Department; Frank H. Rogers, hydraulic engi- neer; and R. E. Brunswick Sharp, assistant hydraulic engineer. Design of the Allis-Chalmers Unit Unit Developed 40,000 Hp. Under Test—Runner Is a One Piece Casting—Hydraucone Draft Tube Used By W. M. White Manager and chief engineer hydraulic department, Allis- Chalmers Manufacturing Company, Milwaukee, Wis. THE hydraulic turbine forming Unit No. 16 of the extension to station No. 3 is rated at 37,500 hp. when operating at the normal speed of 150 r.p.m. under the normal operating head of 214 ft. and is designed to use 1,500 sec.-ft. when operating at best efficiency. The unit has recently been put under full load and actually develops at normal head and speed a capacity of 40,000 hp. Unit No. 16, which is the first one installed and the first placed in operation, was designed and built by the Allis-Chalmers Manufacturing Co. at Milwaukee, Wis. Since the design of the entire Allis-Chalmers hydro-electric unit was under the control of a single group of engineers it was possible to consider the structure properly as a homogeneous unit and correctly proportion and correlate the various elements. Such proceedure was followed so that the completed machine possesses a unity not frequently met with in hydro- electric practice. The design of the turbine embodies several new fea- tures of interest to water-power engineers, particularly the form of casing, governor, interconnecting barrel, brake support and draft tube used. The water for the units in the new station is taken from the old Hydraulic Power Co. canal and is delivered to the unit through a 15|-ft. diameter penstock and controlled by Johnson valve located near the turbine. The discharge diameter of the Johnson valve is 10 ft. and to this is connected a short section of the feeder pipe which increases in diameter to 11 ft. at the en- trance to the plate-steel circular section spiral casing- surrounding the turbine and supplying water through guide vanes to the runner. The casing is made up of a multiplicity of conical sections of plate steel of gradually reducing cross-sectional area around the turbine. The plates are riveted to the flanges of a cast-steel speed ring which forms an integral part of the casing and the foundation of the turbine parts. The thickness of the plate steel of the casing at the 11 ft. diameter is i in. This thickness is reduced gradually to J in. at the smallest section of the casing. The roundabout seams of the casing are lap joint, double riveted and the longitudinal seams are lap joint, triple riveted, while the connection at the ends of the plate to the cast-steel speed ring is made by a triple row of rivets. The rivets are countersunk on the inside. Plate-Steel Casing Fig. 17 gives a view of the casing as erected in power house. There are about six thousand rivets in the casing which were driven by a No. 90 air hammer. The heads were formed by lj-in. by H-in. snaps. The casing was calked inside and outside. It was con- creted in without an hydrostatic test. No leaks of any kind have developed about the casing. Those who are familiar with plate-steel work will readily understand that plate thickness of 11 in. can be readily worked so that a casing substantially of the size shown could be designed and constructed for heads up to 350 ft. without unduly stressing the material or sacrificing tightness and without going beyond normal practice obtaining in plate work of this nature. Above all, how- ever, all uncertainties as to casting strains are elimi- nated and only strictly dependable material used. On account of the simplicity of the construction and low cost relative to cast iron this casing was made larger in diameter so as to reduce losses due to friction, thereby tending toward higher turbine efficiency. Water is controlled from the casing to the runner by means of twenty cast-steel guide vanes. Each vane has pivots on each end for the support of the vane and for controlling its position. Each vane is operated by means of a lever secured to the extended pivot through a link connecting to the shifting ring located on the outside of the turbine. Each guide vane is held in position by two thrust bearings, one sup- porting the weight and the other resisting the upward hydraulic thrust of the stem through the stuffing box when the unit is in operation. The thrust bearings are so adjusted that the guide