XIII, A, 3 Ycasiano and Valencia: Producer-gas Plant 



109 



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Fig. 7. Condenser. 



head and which ends when it reaches 

 its position nearest the crank. Dur- 

 ing this interval both the suction and 

 exhaust valves are closed. 



4. Exhaust or fourth stroke, which 

 begins as soon as the piston again 

 leaves its position nearest the crank 

 and which ends when it reaches its 

 position nearest the cylinder head. 

 During this interval the suction valve 

 is closed, while the exhaust valve is 

 open. 



Manner of governing the 

 engine. — The governor of the 

 engine belongs to the class that 

 is called "precision" method of 

 governing. 



The mixture of gas and air has a constant proportion at all loads of 

 the engine. This mixture of constant quality is throttled to suit the load 

 by the action of a fly-ball governor, which shifts the position of the fulcrum 

 about which the lever of the mixture inlet valve of the engine turns, thus 

 increasing or decreasing the lift of the valve. 



Dynamo. — The gas engine drives directly a 50-kilovv^att com- 

 pound-wound direct-current 110-volt dynamo manufactured in 

 Germany. 



This is wired in parallel with two 37.5-kilowatt compound-wound direct- 

 current 110-volt dynamos made in the United States, which are driven 

 directly by two high-speed steam engines provided with Rite's inertia 

 governors. Fig. 8 gives the details of connections of the dynamos to the 

 main switchboard. 



Auxiliary motors. — The power plant of the Bureau of Science is run 

 continuously and gives an available electric power supply, at any time, of 

 110 volts direct current. In choosing the type of motors to run the auxi- 

 liary machinery of the producer-gas power plant, it was decided that 

 electric motors were most suitable. A 9-horsepower motor drives the air 

 blower, the centrifuges, and the water pump, and a 2-horsepower motor 

 drives the air compressor, which is used only to fill the compressed-air 

 tank for starting the gas engine. 



METHOD OF OPERATION 



Starting the producer. — When the producer is empty, ascer- 

 tain first that the grate is clean and the wall free of clinkers. 

 Open the three-way cock in the gas flue to the chimney. Build 

 a good wood fire on the grate, close the doors, and start the air 

 blower. Feed enough coal through the charging hopper, about 

 30 kilograms at intervals of about ten minutes, but be careful 



