Steam, Its Generation and Use

by Babcock & Wilcox Company

(B) Corrections for moisture in steam.

(C) Correction for live steam used.

(D) Equivalent evaporation.

(E) Heat balance.

(F) Total heat of combustion of coal.

(G) Air for combustion and the methods recommended for calculating these results are in accordance with those described in different portions of this book.

16. DATA AND RESULTS

The data and results should be reported in accordance with either the short form or the complete form, adding lines for data not provided for, or omitting those not required, as may conform to the object in view.

17. CHART

In trials having for an object the determination and exposition of the complete boiler performance, the entire log of readings and data should be plotted on a chart and represented graphically.

18. TESTS WITH OIL AND GAS FUELS

Tests of boilers using oil or gas for fuel should accord with the rules here given, excepting as they are varied to conform to the particular characteristics of the fuel. The duration in such cases may be reduced, and the “flying” method of starting and stopping employed.

The [table of data and results] should contain items stating character of furnace and burner, quality and composition of oil or gas, temperature of oil, pressure of steam used for vaporizing and quantity of steam used for both vaporizing and for heating.

[TABLE DATA AND RESULTS OF EVAPORATIVE TEST] SHORT FORM, CODE OF 1912 1 Test of boiler located at to determine conducted by 2 Kind of furnace 3 Grate surface square feet 4 Water-heating surface square feet 5 Superheating surface square feet [Pg 275] 6 Date 7 Duration hours 8 Kind and size of coal AVERAGE PRESSURES, TEMPERATURES, ETC. 9 Steam pressure by gauge pounds 10 Temperature of feed water entering boiler degrees 11 Temperature of escaping gases leaving boiler degrees 12 Force of draft between damper and boiler inches 13 Percentage of moisture in steam, or number degrees of superheating per cent or degrees TOTAL QUANTITIES 14 Weight of coal as fired[72] pounds 15 Percentage of moisture in coal per cent 16 Total weight of dry coal consumed pounds 17 Total ash and refuse pounds 18 Percentage of ash and refuse in dry coal per cent 19 Total weight of water fed to the boiler[73] pounds 20 Total water evaporated, corrected for moisture in steam pounds 21 Total equivalent evaporation from and at 212 degrees pounds HOURLY QUANTITIES AND RATES 22 Dry coal consumed per hour pounds 23 Dry coal per square feet of grate surface per hour pounds 24 Water evaporated per hour corrected for quality of steam pounds 25 Equivalent evaporation per hour from and at 212 degrees pounds 26 Equivalent evaporation per hour from and at 212 degrees per square foot of water- heating surface pounds CAPACITY 27 Evaporation per hour from and at 212 degrees (same as Line 25) pounds 28 Boiler horse power developed (Item 27 ÷ 34½) boiler horse power 29 Rated capacity, in evaporation from and at 212 degrees per hour pounds 30 Rated boiler horse power boiler horse power 31 Percentage of rated capacity developed per cent ECONOMY RESULTS 32 Water fed per pound of coal fired (Item 19 ÷ Item 14) pounds 33 Water evaporated per pound of dry coal (Item 20 ÷ Item 16) pounds 34 Equivalent evaporation from and at 212 degrees per pound of dry coal (Item 21 ÷ Item 16) pounds 35 Equivalent evaporation from and at 212 degrees per pound of combustible [Item 21 ÷ (Item 16 - Item 17)] pounds EFFICIENCY 36 Calorific value of one pound of dry coal B. t. u. 37 Calorific value of one pound of combustible B. t. u. 38 Efficiency of boiler, furnace and grate ( 100 × Item 34 × 970.4 ––––––––––––––––––––––––– Item 36 ) per cent 39 Efficiency of boiler and furnace ( 100 × Item 35 × 970.4 ––––––––––––––––––––––––– Item 37 ) per cent COST OF EVAPORATION 40 Cost of coal per ton ofpounds delivered in boiler room dollars 41 Cost of coal required for evaporating 1000 pounds of water from and at 212 degrees dollars [Pg 276]