222 TWO MARINE INSTALLATIONS OF PRODUCER GAS. 



The operation of the producer is exceedingly simple and mechanically 

 and chemically similar to that of the self -feeding parlor stove. In starting 

 a new fire, a few bushels of shavings and charcoal (preferred) or wood are 

 thrown on the grate. As soon as this is lit off the fan is started, giving a 

 gentle blast to the fire. Coal is then fed through the hopper until the 

 producer is full. Very frequently good gas of sufficient volume to operate 

 the engine can be obtained in thirty minutes. The coal on the grate is 

 burned to complete combustion (CO2) . This gas is reduced to CO on pass- 

 ing through the red and black hot fuel zones above. The fire can be kept 

 for months at a time and the producer is capable of being operated continu- 

 ously for long periods without shutting down the engine, the removal of 

 the ashes and poking down the clinker being done while the engine is in 

 full operation, and this without any serious fluctuations in the quality 

 of the gas and consequently the speed of the engine. The entire system 

 of producer, scrubber and piping while the engine is operating is under 

 vacuum, the suction of the engine inducing a draft in the producer pro- 

 portional to its speed or power requirements. 



On a plant of the size of the Mary A. Sharp, it takes about thirty 

 minutes to clean the fire in the morning, that is, poke down the clinkers, 

 rake out the ashes, and fill the producer with coal. With a small (two 

 horse-power) auxiliary engine for running a blower, it takes about ten to 

 fifteen minutes to get up gas, a total of three-quarters of an hour from the 

 time the engineer steps aboard until he is ready to get under way. On long 

 trips the fire should be sliced on the grate and poked from the top every 

 hour. Once an hour is often enough to charge with coal. On short runs 

 of an hour, or an hour and a half, no poking is necessary. 



Perhaps the most interesting feature of these two installations is the 

 engine. It is two-cycle in principle, in that an explosion is effected in each 

 cylinder each revolution, scavenging in action and substantially equivalent 

 to the four cycles in efficiency. The commercial use of producer gas on 

 ship-board involves the vital questions of weight, space, first cost, and 

 simplicity. The two-cycle principle naturally appeals to the imagination 

 of the marine engineer as fulfilling these requirements more easily than the 

 four-cycle provided it can be made economical and reliable. In land practise 

 we know of the Koerting two-cycle engines which are economical on full 

 loads. Now a marine engine is operated at full power continuously. Hence 

 it is evidently possible to fulfil the specifications for economy. Reliability 

 is a matter of careful design, good material and workmanship, and high 

 grade ignition devices. If the use of a four-cycle engine is made difficult 

 by reason of its weight, space required and first cost, the two-cycle engine 

 should make marine producer gas power installations commercial. 



