Part 28 (1/2)
3rd For equal heat value, oil occupies very e space may be at a distance froher efficiencies and capacities are obtainable with oil than with coal The combustion is more perfect as the excess air is reduced to a minimum; the furnace temperature may be kept practically constant as the furnace doors need not be opened for cleaning or working fires; smoke may be eliminated with the consequent increased cleanliness of the heating surfaces
5th The intensity of the fire can be alulated to meet load fluctuations
6th Oil when stored does not lose in calorific value as does coal, nor are there any difficulties arising froration, such as may be found when coal is stored
7th Cleanliness and freedom fro in wear and tear onproperty due to such dust
The disadvantages of oil are:
1st The necessity that the oil have a reasonably high flash point to er of explosions
2nd City or town ordinances may impose burdensoe tanks, which in the case of a plant situated in a congested portion of the city, ht make use of this fuel prohibitive
3rd Unless the boilers and furnaces are especially adapted for the use of this fuel, the boiler upkeep cost will be higher than if coal were used This objection can be entirely obviated, however, if the installation is entrusted to those who have had experience in the work, and the operation of a properly designed plant is placed in the hands of intelligent labor
TABLE 47
RELATIVE VALUE OF COAL AND OIL FUEL
+------+--------+-------+-----------------------------------------------+ |Gross | Net | Net | Water Evaporated frorees Fahrenheit per Pound of Coal | |Effic-|Effici- |oration+-----+-----+-----+-----+-----+-----+-----+-----+ | iency|ency[46]| from | | | | | | | | | | with | with |and at | | | | | | | | | | Oil | Oil | 212 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | | Fuel | Fuel |Degrees| | | | | | | | | | | |Fahren-| | | | | | | | | | | | heit +-----+-----+-----+-----+-----+-----+-----+-----+ | | | per | | | | | Pound | Pounds of Oil Equal to One Pound of Coal | | | |of Oil | | +------+--------+-------+-----+-----+-----+-----+-----+-----+-----+-----+ | 73 | 71 | 1354 |3693|4431|5170|5909|6647|7386|8124|8863| | 74 | 72 | 1373 |3642|4370|5099|5827|6556|7283|8011|8740| | 75 | 73 | 1392 |3592|4310|5029|5747|6466|7184|7903|8621| | 76 | 74 | 1411 |3544|4253|4961|5670|6378|7087|7796|8505| | 77 | 75 | 1430 |3497|4196|4895|5594|6294|6993|7692|8392| | 78 | 76 | 1449 |3451|4141|4831|5521|6211|6901|7591|8281| | 79 | 77 | 1468 |3406|4087|4768|5450|6131|6812|7493|8174| | 80 | 78 | 1487 |3363|4035|4708|5380|6053|6725|7398|8070| | 81 | 79 | 1506 |3320|3984|4648|5312|5976|6640|7304|7968| | 82 | 80 | 1525 |3279|3934|4590|5246|5902|6557|7213|7869| | 83 | 81 | 1544 |3238|3886|4534|5181|5829|6447|7125|7772| +------+--------+-------+-----+-----+-----+-----+-----+-----+-----+-----+ | | | Net | | | | |Evap- | | | | |oration| | | | | from | | | | |and at | | | | | 212 | Barrels of Oil Equal to One Ton of Coal | | | |Degrees| | | | |Fahren-| | | | | heit | | | | | per | | | | |Barrel | | | | |of Oil | | +------+--------+-------+-----+-----+-----+-----+-----+-----+-----+-----+ | 73 | 71 | 4549 |2198|2638|3077|3516|3955|4395|4835|5275| | 74 | 72 | 4613 |2168|2601|3035|3468|3902|4335|4769|5202| | 75 | 73 | 4677 |2138|2565|2993|3420|3848|4275|4703|5131| | 76 | 74 | 4741 |2110|2532|2954|3376|3798|4220|4642|5063| | 77 | 75 | 4807 |2082|2498|2914|3330|3746|4162|4578|4994| | 78 | 76 | 4869 |2054|2465|2876|3286|3697|4108|4518|4929| | 79 | 77 | 4932 |2027|2433|2838|3243|3649|4054|4460|4865| | 80 | 78 | 4996 |2002|2402|2802|3202|3602|4003|4403|4803| | 81 | 79 | 5060 |1976|2371|2767|3162|3557|3952|4348|4743| | 82 | 80 | 5124 |1952|2342|2732|3122|3513|3903|4293|4683| | 83 | 81 | 5187 |1927|2313|2699|3085|3470|3856|4241|4627| +------+--------+-------+-----+-----+-----+-----+-----+-----+-----+-----+
[Illustration: City of San Francisco, Cal, Fire Fighting Station No
1 2800 Horse Power of Babcock & Wilcox Boilers, Equipped for Burning Oil Fuel]
Many tables have been published with a view to co the two fuels
Such of these as are based solely on the relative calorific values of oil and coal are of limited value, inasher than that obtainable with coal Table 47 takes into consideration the variation in efficiency with the two fuels, but is based on a constant calorific value for oil and coal This table, like others of a siuide, cannot be considered as an accurate basis for comparison This is due to the fact that there are nu into the problereater extent than do the relative calorific values of two fuels So at the true basis for co possible, the space available for fuel storage, the facilities for conveying the oil by pipe lines, the hours during which a plant is in operation, the load factor, the quantity of coal required for banking fires, etc, etc
The only exact es and costs of the two fuels is by considering the operating expenses of the plant with each in turn, including the costs of every ite Oil Fuel--The require petroleuh
2nd When atoht into contact with the requisite quantity of air for its combustion, and this quantity ases
3rd The mixture must be burned in a furnace where a refractory material radiates heat to assist in the coh temperatures developed
4th The coases co surfaces or otherwise the flanite later in the flue connection or in the stack
5th There must be no localization of the heat on certain portions of the heating surfaces or trouble will result fro
The first requirement is met by the selection of a proper burner
The second require the air into the furnace, either through checkerwork under the burners or through openings around the the quantity of air to meet variations in furnace conditions
The third requirened as to give a sufficient area of heated brickwork to radiate the heat required to maintain a proper furnace teiving ample space for the coas travel of sufficient length to insure that this co surfaces