xiii, A.3 Ycasiano and Valencia: Producer-go^ Plant 127 



with water, which evolves sufficient vapor to protect the grate 

 and the wall of the producer. 

 Guldner " says : 



An ample supply of steam to the generator is of advantage from a 

 practical standpoint, since it tends to decrease clinkering and to prevent 

 the rapid burning away of lining and grates. Too high a percentage of 

 hydrogen in the gas, however, leads to heavy explosions in the cylinder 

 of the engine. Only a few engines can stand from 7 to 10% of hydrogen 

 in the mixture, i. e., from 15 to 20% in the producer gas; in most of them, 

 under continued heavy load, a troublesome knocking appears as soon as 

 the gas contains more than 10% of hydrogen. The composition of the 

 producer gas should therefore not be made entirely dependent upon the 

 efficiency of the gasification process. 



Disturbing the fire. — When there is necessity of performing 

 an operation that will disturb the fire, if Batan coal is being 

 used, the ash pit should be dried first, as the glowing particles 

 of coal and hot ashes falling in the water will cause a large 

 liberation of hydrogen and consequent pounding of the engine. 

 Once the ash pit is dry, the necessary stoking should be done 

 as quickly as possible so as not to leave the grate unprotected 

 by the cooling action of the water vapor for a long time. 



After finishing the operation of stoking, the water supply 

 of the ash pit should be immediately opened after removing any 

 hot refuse consisting of ashes and small particles of coal and 

 broken clinkers that have fallen through the grate. When 

 Fushon coal is used, these precautions are not necessary. 



Cleaning the fire. — In cleaning the fire when Batan coal was 

 used, there was no appreciable alteration in the action of the 

 gas engine, even when the period of cleaning lasted as long as 

 twenty minutes. Unfortunately this was not the case with 

 Fushon coal, for, after three minutes of stoking, the gas engine 

 usually slowed down and stopped. The cause of it was found to 

 be due to the formation of a gas very rich in hydrocarbons result- 

 ing in a mixture too rich for ignition. Therefore the air throttle 

 valve of the engine was widely opened during the process of stok- 

 ing, and the gas valve was left at about 20 per cent of its full 

 opening. At these positions of the valves the engine worked 

 well, and the period of stoking could be prolonged even to twenty 

 minutes, affording ample time thoroughly to clean the fire. A 

 few minutes after cleaning the fire the gas and air throttle valves 

 should be returned to their original positions. 



' Giildner, Hugo, The Design and Construction of Internal-Combustion 

 Engines. Translation by Herman Diederichs (1910) , 521. 



