Jdlt 22. 1920 



The Florists^ Review 



15 



jet of steam, causes some draft. The 

 burner holes should be large enough to 

 nllow running a small rod alongside the 

 burner to break off any coke which may 

 form on the burner tip or the brick- 

 work near it; an additional con- 

 venience is a rod flattened at one end 

 and bent at right angles, which may be 

 reached in and held over the end of the 

 burner, so that the steam can be blown 

 back through the oil tube and out 

 ihrough the tee, from which the plug 



has been removed, thus cleaning out 

 the burner. 



Steam Jet with Hot Water. 



Finally, it should be noted that if a 

 steam jet burner is used with a hot 

 water boiler, an auxiliary steam boiler, 

 fired with coal, wood or gas, will be re- 

 quired continuously to furnish steam to 

 heat and atomize the oil. With twenty 

 to twenty-five pounds pressure the aux- 

 iliary boiler must be large enough to 



evaporate and heat to the required 

 pressure one-half gallon of water for 

 every gallon of oil burned. There are 

 two disadvantages in this arrangement. 

 It will be more difficult to keep the 

 pressure in the smaller boiler constant, 

 as it must be kept, since the slightest 

 change there will upset the adjustment 

 of the oil burners. And the greater 

 length of the steam line to the burner 

 seems, in my experience, to make a good 

 fire more difficult to obtain. 



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<^ POINTS PRO AND CON ^ 



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on. HEATING. 



Is It Coming or Ooing? 



Nowadays no greenhouse man needs 

 to have his attention called to the se- 

 riousness of the fuel problem. His own 

 experience has told him of that. The 

 scarcity of available labor, too, has 

 added to his worries. Many greenhouse 

 owners have sought, and others are 

 considering, at least a partial solution 

 to the first problem and help in meet- 

 ing the second by the adoption of oil 

 heating in their ranges. A summary of 

 some of the important considerations in- 

 volved may simplify the question for 

 those who have not yet made the de- 

 cision. 



For the man who is debating the 

 change from coal to oil, the first ques- 

 tion is likely to be, is oil cheaper than 

 coalf That will depend, of course, on 

 local conditions. It is generally esti- 

 mated that three to three and one-half 

 barrels of crude oil or of fuel oil are 

 equivalent to one ton of bituminous 

 coal. That estimate will give some basis 

 for comparison when the local prices 

 for oil and coal have been ascertained. 

 In California, where oil is comparatively 

 plentiful and coal is scarce, oil is said 

 to be sixty per cent cheaper than coal; 

 in other districts the saving has been 

 stated as being from ten to thirty per 

 cent. 



Tlie Nation's Oil Supply. 



But what, it may be asked, about this 

 scarcity of oil! Is there danger of in- 

 stalling the oil equipment and then 

 finding, after a few years' use, that 

 the tremendous demand for petroleum 

 products has drained the country's oil 

 resources! In the first place, the actual 

 installation of the oil burners is com- 

 paratively simple; the greater expense 

 will result from the provision for the 

 storage and transmission of the oil. 



But the question as to the nation's 

 supply of oil is more difficult to answer; 

 the partisans of oil on one side and coal 

 on the other seldom seem to agree as to 

 the facts. An unprejudiced view, how- 

 ever, that recently expressed by David 

 White, of the United States Geological 

 Survey, is as follows: The United 

 States has, so far as known, about 

 7,000,000,000 barrels of petroleum avail- 

 able in the ground; the present annual 

 production is about 400,000,000 barrels; 

 during the last eight years the average 

 annual increase in production has been 

 22,000,000 barrels; the present un- 

 derground supply will, in theory, be 

 exhausted in about seventeen years, but, 

 because of delay in locating all the 

 resources, the production will pass its 



peak in five or possibly in three years, 

 while decreasing quantities of petroleum 

 will be produced during several decades. 

 At present this c(mntry is annually 

 using 47,000,000 barrels in excess of its 

 production. 



Oil Shale a Possible Source. 



In this connection, some hope may be 

 derived from the fact that this country 

 has huge deposits of oil shale, a mineral 

 substance related to cannel coal. This 

 oil shale yields from twenty to eighty 

 gallons of oil per ton. The United 

 States Geological Survey estimates that 

 in northwestern Colorado and north- 

 eastern Utah there is enough oil shale 

 to yield 40,000,000,000 barrels of oil. 

 And that is only part of the nation's 

 oil shale resources. But the oil shale 

 industry will have to be built up as the 

 coal industry, of which it may be the 

 successor, has been built up. 



Turning from supply to demand, we 

 find that the program of the United 

 States Shipping Board calls for 1,734 

 oil-burning merchant ships by 1922 and 

 that the board has called for 50,000,000 

 barrels of fuel oil for 1920 and 30,000,- 

 000 barrels for the first half of 1921. 

 It is estimated that this fleet when 

 completed will require about 80,000,000 

 barrels of oil annually, an amount ap- 

 proximately equivalent to one-half of 

 all the fuel oil nowVproduced in this 

 country. The navy now requires 8,000,- 

 000 barrels of fuel oil annually. Sec- 

 retary of Commerce Alexander has re- 

 cently suggested the holding of a con- 

 ference of representatives of the lead- 

 ing refineries and users of fuel oil to 

 work out some joint plan of distribu- 

 tion. 



Growing Competition for Oil. 



Consequently, while the individual 

 greenhouse owner may decide, after his 

 investigation of local prices and local 

 supply, that the change from coal to 

 oil will be an economy worth adopting, 

 even for a few years, yet the long- 

 range outlook has its clouds. The oil- 

 burning greenhouse establishment will 

 have to meet severe competition in se- 

 curing its fuel, competition not only 

 with the government but with the large 

 number of private concerns which use 

 oil for heating or for steam power pro- 

 duction. 



However, aside from the matter of 

 economy as compared with coal, oil has 

 advantages as a fuel which may still 

 turn the balance. Oil weighs about one- 

 half as much as coal of equivalent heat 

 value and occupies one-third as much 

 space. It does not deteriorate when 

 stored. It can be handled more easily 



than a solid fuel like coke or coal. 

 There are no ashes, much less dirt than 

 with coal and less labor required. The 

 lessening of work is true also in the 

 firing of the boiler; while a pump will 

 be required if the gravity system is not 

 used, the oil fuel can be piped and will 

 not have to be shoveled. Control by 

 thermostat may make oil heating prac- 

 tically automatic, so long as enough fuel 

 is supplied. The heat in the combustion 

 chamber is more continuous with oil 

 than with coal, since the doors do not 

 have to be opened for firing. Loss of 

 heat up the stack is diminished, owing 

 to the smaller amount of air required 

 for the complete combustion of oil. A 

 large increase in steam capacity is possi- 

 ble; the grate area limits the amount 

 of coal which can be burned efficiently, 

 but oil is independent of that. 



The Equipment. 



Just how complicated the oil burning 

 equipment will be depends, of course, 

 upon the particular system adopted. In 

 addition to the storage tank, which is 

 likely to be below the level of the boiler, 

 a smaller supply tank a few feet above 

 the burner will probably be employed, 

 with a pump to force the oil up into it. 

 If the burner is of the steam jet type 

 and the heating system is hot water, a 

 small auxiliary boiler will be required 

 to furnish steam to heat and atomize 

 the oil. When the burner is of the kind 

 which atomizes the oil by air or by 

 mechanical means, a separate heater 

 may be needed for heavy oils unless an 

 arrangement for heating is incorporated 

 with the pumping system. A water 

 separator, which may be made from an 

 old steam trap, may also be included in 

 the system. ^ 



Among the various firms supplying 

 oil-burning equipment for greenhouse 

 heating, the following may be named, 

 as representing various types of burner- 

 W. S. Ray Mfg. Co., 29 Spear street, 

 San Francisco, Cal.; Rotary Oil Burner 

 Co., 159 Twelfth street, Oakland, Cal.; 

 Fess System Co., 218 Natoma street, 

 San Francisco, Cal.; S. T. Johnson Co., 

 1337 Mission street, San Francisco, Cal.; 

 Fuel Oil Equipment Co., 218 State-Lake 

 building, Chicago. 



For storing oil, the small tanks are 

 constructed of steel, -ft-inch or 14-inch, 

 and the large ones frequently of con- 

 crete or of steel and wood. In capacity 

 they range generally from 1,000 gallons 

 up, some being of carload capacity. 

 These storage tanks are usually placed 

 underground, preferably below the frost 

 line. Unless they are close to the rail- 

 road, a tank wagon is required to trans- 

 port the oil from car to storage tank. 



