The Iron Age 1921-06-09: Vol 107 Iss 23

THE IRON AGE New York, June 9, 1921 ESTABLISHED 1855 VOL. 107: No 23 Fuel Economy of a Drop Forge Plant Prime Importance of Correct Valve Setting and Absence of Leaks — Test Results Show Large Savings Effected by Careful Attention to Details BY N. A. CRAIGUE AND C. H. L. THOMPSON NLESS a special. effort is made in the nature of | | certain repairs, the steam consumption of drop forging hammers is large—so large in some cases as to offer an excellent opportunity, by decreas- ing this steam use and keeping wastes at a minimum, to lower production costs at a very small expenditure of effort. This excessive use of steam is due to the severe service the hammers receive in producing drop forgings. The continuous shock and vibration result in rapid wear of all operating parts of the hammers, keeping the repair crew on the jump to maintain them in operating condition. In most cases only sufficient repairs are made to permit the forging hammer to turn out the work satisfactorily, with no direct atten- tion paid to decreasing steam consumption, by making other repairs and adjustments. Manufacturers of drop-forging hammers are very chary in advancing information on the steam consump- tion of hammers, for the very good reason that they realize this to be a function of the use and condition of the equipment. They state that the steam consump- tion will range between 2 and 3 boiler hp. per 100 Ib. of falling weight. It can be readily seen that the dif- ference between 2 and 3 b.hp. per 100 Ib. falling weight would have an appreciable effect on the installation of a new forge plant of (say) 100,000 pounds, for if 3 is used, one-half more boiler equipment, or 1000 b.hp. *The du Pont Engineering Co., Wilmington, Del Illustrating Faulty Setting of Valves Ram at Top of Stroke TM would be added. At an installation cost of $120 per b.hp., $120,000 would be expended for the extra boilers. As a matter of fact, the steam consumption of new hammers will be much less than 2 b.hp., or for sake of simplicity 64 lb. of steam per hr., per 100 Ib. of falling weight. This also holds true if old hammers are prop- erly repaired. On the other hand, if the hammers are not given the necessary attention to keep the steam consumption at a minimum, this may be as great as 90 lb. of steam, or nearly 3 b.hp., per 100 lb. of falling weight. To show the importance of this difference one plant, having 138,000 lb. of nominal falling weight of steam hammers, made a fuel saving of $5,000 per month by reducing steam consumption from 90 lb. to 62 lb. per 100 lb. of nominal falling weight. In the majority of forging plant designs, some method of utilizing the exhaust steam is provided. It may be used to heat buildings in winter, ot low pres sure steam turbines may be installed; but rarely does the equipment use all of the exhaust available, for in the summer, for approximately five months, heating is not necessary, and due to varying load factor the turbines do not use all the exhaust available. Then when it is necessary to exhaust the steam to atmos- phere, a third of the steam consumed may be used wastefully. The superintendent of a forge plant will argue rightly that his job is to produce forgings to agree Illustrating Correct Setting of Valves Ram at Top of Stroke 1521 oe ee A LR te iar ese ee gentamicin: ae tn oe 1522 with the production schedule. His labor costs may be low (a bonus system of wages may be in effect) and the forgings of first class quality; yet the steam loss in the shop may amount to $200 per day or more, de- pendent upon the size of the plant and the number of hammers installed. With present economic conditions, the reaching of maximum production from the installed equipment may not be so important as producing the r | , 7 ” a7 - J | { | | } | * —~T T —— — J : } « , x % ,- x i LA £ Peae \ . Testing Apparatus LOA . . > L-) with Condensing | Surface of 406 Sq Ft. and Capacity of 10,000 Lb, per Hour a 4 forgings at as low a cost as possible. Economy of pro- duction is probably now the first requisite. In the campaign for reducing operating costs, one of the most profitable sources of attack is the steam waste of the hammers. To accomplish this object con- siderable continuous test Means and methods of doing this work, as given herewith Descriptions of testing equipment and methods are of value, and can be applied with modifica- plant. work is necessary. can be used. tions to any steam drop forging Computing Steam Costs for Fuel Only Generally the only saving effected, when steam con- sumption is decreased, is in the use of fuel. Of course, decreasing the steam load on the boilers may so lower the overload rating that the repair costs are lessened, but this is questionable. Also, reducing the steam load rarely affects the number of firemen. servative in the statement of saving involved, it is safe to figure only the reduction in fuel. Then the cost of steam for fuel only can be used for showing the dollars This may be com- So, to be con- gain when economies are effected. puted as follows: Fuel cost of steam) in dollars Cost of coal in dollars* per lb. Actual lb. per lb. r ii per 1b. j water evaporated of fuel fired Closing Steam Valves During Non-Operating Periods At the start of a test on a forge plant one of the first points to check is the tightness of the throttle or rocker valves on the hammers. During idle periods of the shop the steam should be completely shut off the hammer. In most cases these valves do not close tight- ly; they allow steam to leak through into the hammer, condense or exhaust to waste. Then, to and either handling coal outside of boiler room, as generally proportional to quantity of coal *Include cost of 1andling costs are a used THE IRON AGE June 9, 19: eliminate this loss, it is necessary to utilize the m steam valves, either of the globe or gate type, closi) these valves during the non-operating periods. If th is any doubt of these valves seating tightly, the bonn should be taken off and if necessary new seats installe: This waste of steam during non-operating periods quite important and is the easiest to correct. At o1 shop this simple expedient resulted in a fuel saving of $50 per day, during the 8-hr. shut-down period (includ ing Saturday afternoon and Sunday), or $2,000 p month reduction in fuel as burned. To emphasize this further, a rather unique situa tion developed in the boiler room supplying the for; plant where this saving was effected. The test arranged to shut off the individual valves on the stean feeder lines to the hammer during idle periods. U: fortunately the boiler room was not warned of the con When these valves wer crew ing reduction in steam load. shut off every pop valve on the boilers opened, releas ing steam to the atmosphere. The firemen were kept busy checking fires and the boiler room foreman hastily sent out several men to main valve had been inadvertently shut off. This situation was out of the ordinary run of event and the firemen at the time did not know the reason for the sudden load, theretofore during idle periods the main valves on the hammers discover what headei decrease in because were allowed to remain open, except in case of repairs. This resulted in the steam leaking through the ham- mers, part of it exhausting and part condensing in the cylinders. When the closing of these valves became a regular part of the forge shop routine, two of the three r 4 f Curves Showing Reduction in Steam Con imption After Needed Repairs Had Been Made to Various Classes of Steam Drop Hammers boilers were banked during the eight-hour shut dow! period. The foregoing represents the saving that The next step is the r¢ Ty can effected during idle periods. ducing of steam consumption during operation of hammers. This, the most difficult part of the work, necessitates considerable testing in order to prove whe! and where repairs are warranted. The causes wastes can be summarized as follows: 1—Barrel shape of the steam cylinder. June 9, 1921 This results in the steam leaking past the piston while hammer is in motion. Generally, the cylinder must be re-bored and a sleeve in- serted. 2—Bad setting of control valves. The valves can be so set that the hammer will operate properly, yet be very wasteful of steam. This is discussed in detail further on. 3—Leaky stuffing boxes. This waste is‘obvious and should be kept at a minimum. Curves Showing the Steam Consumption in Pounds per Pound of Forgings Made, Indicating Importance of Keeping Hammers in Good Repair 4—Cracked castings, cylinder walls, piping, ete. This waste is also obvious. 5—Control valves worn and leaking steam. If this is very bad, the hammer will not function properly. 6—Valve seats on the main inlet and main ex- haust valves worn and leaking steam. It is important that these latter valves be shut off tight during non-operating periods, and even during working periods when it is necessary to cool the dies. It is better to block the dies apart rather than keep steam on, to hold the hammer up by the steam pressure on the upward stroke, with part of the steam exhaust- ing to waste, due to the valve lead. Testing Equipment Due to the pulsating effect of steam as used by ham- mers, it is impossible, with the present state of flow- meter development, to measure the high-pressure steam in the supply line on individual hammers. In conse- quence it is necessary to condense the exhaust steam and weigh the condensate or water. For this purpose, some form of condenser is required with ample cold water available for cooling purposes. The condensate can either be weighed by means of platform scales and barrels or some form of condensation meter can be used, of which several good makes are available. For obtaining the test results as given, the follow- ing described equipment was used. One diagram shows the general plan of apparatus. Condensers. Box No. 1—125 sq. ft. of condensing surface. 6 lengths 12 ft. long, 6-in. pipe. THE IRON AGE 1523 Box No. 2—Same as No. 1. Box No. 3—78 sq. ft. of condensing surface. 2 lengths 12 ft. long, 4-in. pipe; 4 lengths 12 ft. long, 3-in. pipe. Box No. 4—Same as No. 3. All condenser boxes made of tongue and groove 2-in. plank, each box 14 ft. long, 3 ft. wide and 3 ft. deep, braced across ends, bottom, sides, and top with 4%-in. round stay rods. Total sq. ft. of condensing surface, 406 sq. ft. Capacity of condensers, 10,000 lb. of steam per hour, or 25 lb. per sq. ft. of pipe surface per hour.* me The equipment as given is the result of considerable experimental work for measuring the consumption of large 12 000-lb. hammers. During the early stages of the test on the large hammers only 250 sq. ft. of con- densing surface was used. As this was found inade- quate, for the steam consumption was excessive, due to poor condition of the hammer, additional boxes were added. Four condenser boxes gave advantageous flexibility. The cooling water could be used economically, for the discharge water from one box could be used as supply water for the others when hammers of the lower ratings were tested. In addition, for making tests at 0 lb. back pressure, it was desirable to connect the con- densers in parallel, in order to decrease the friction losses in the condenser piping. Pressure Gages. Calibrated test gages were in- stalled on the main steam supply and exhaust line of each hammer under test. Relief Valve. In order not to interfere with the operation of the hammers being tested, an atmospheric relief valve was installed on the exhaust line, and set to open at about 8 lb. pressure. Back Pressure Valve. To obtain the steam con- 000|B HAMMER / 76 ork sy + HAMMER Ry Sanr > f ’ Steam Consumption of Hammers Related to Cubic Inches of Piston Displacement, Showing Importance of Keeping the Hammers in Good Condition sumption of the hammers under actual conditions of about 5 lb. back pressure, an adjustable automatic back *If a better type of condenser were available, or one having copper tubes, this rate could be increased to at least 50 Ib. of steam per sq. ft. per hour, the area of condenser tubes could be cut down to 200 sq. ft., and still give a capacity of 10,000 lb. of steam per hour. a SEINE I CE em gam - ~ ts orang Sanne reese neers = 1524 installed in the exhaust line. It was necessary to install a large strainer in the exhaust line, to prevent pieces of pack- ing from clogging up the condenser or condensation valve Strainer. pressure was meter. This was placed between the relief valve and back pressure valve. Exhaust Header. As each hammer was tested separately, it was necessary to pipe the exhaust from each hammer to the condenser equipment. In all cases this exhaust line was the same size as the hammer ex- haust line (or larger). Weighing Condensate. As condensation meters are thoroughly reliable, one of large capacity was used for weighing the condensate, thus relieving the test men of the necessity of using barrels and scales. In conse- quence, more attention could be paid to the hammer under test. Two steam flowmeters were installed on the two main feeder steam lines to the entire hammer shop. Checking the individual ham- mer condensation tests, based on idle and working hours, and the total steam as shown by the flowmeters, Flowmeters on Entire Shop. THE IRON AGE June 9, 192] table is valuable for designing condensing equipment and determining the amount of water required for test ing various sizes of hammers. Definition of Terms Used in Forging Practice The terms or phrases used in this article are th: ones most familiar to drop forge men, but in order t avoid any possible misinterpretation, all terms defined. Nominal Falling Weight. The ordinary classifica- tion of a hammer, i. e., a 2000-lb. hammer. Actual Falling Weight. The actual weight of the piston, piston rods, ram and falling die. Working Hours. The number of hours that hammer was actually operating during test period. Idle Hours. The time that the hammer stood idle during the test. Lb. Steam in Working Hours. The steam consump- tion during working hours. Lb. Steam in Idle Hours. The steam consumption necessary to hold piston at top of stroke when hammer is idle. Total Lb. Steam, are the Total consumed during the period showed the total measurements as recorded by the of test. RECAPITULATION OF TEST DATA Steam, Lb Average Steam Lbs. Steam Falling per Sq. In Hammer! Steam Consumption Consumption per Hr. per Lb. Total Weight Back Hours Work- Per Per Falling Weight Forgings Nom Pres- Pres- Work ing Idle Working Idle Per Nom- Num- Ne inal Actual sure sure ing Idle Hrs Hrs Total Hr Hr Hr. inal Actual Pounds ber Remarks 1.000 1.100 4] 6 10 4 12.200 8,200 20,400 1,220 911 1,074 1.07 0.985 2.735 730 Poor 1.000 1.100 9? 6 S 2 8.100 1,200 9,300 1,012 600 930 0.93 0.845 2,150 574 Good 1,000 1,100 91 0 6% 2% 8,700 2,800 11,500 1,390 1,120 1,315 1.32 1.196 2,622 700 Poor { 1.500 1.750 6 5, 7% 9 9,300 1,800 11,100 1,240 900 1,170 0.78 0.67 995 362 Poor ) 1.500 1.750 g9 5 ( l 5.400 600 6,000 900 600 857 0.57 0.395 1,130 411 Good 6 1,506 2,200 101 0 7 1% 7,500 100. 7,900 1,024 268 $96 0.598 0.407 1638 596 Fair 1500 1,750 98 0 ' 6,300 4000 10,300 1,110 1,045 1,085 0.72 0.62 1097 399 Poo! 2 000 9200 101 0 1% 6,700 2,300 9,000 1,340 1,315 1,330 0.665 0.605 1520 451 Poor ) 000 2200 100 5 114 0 5.400 Je 5.400 1,270 000 1,270 0.635 0.578 1.725 512 Good 00 2 200 97 5 81, 1! 9.500 1,000 10.500 1.170 667 1.050 0.525 0.478 2.829 8389 Good l 2.000 2.200 10 5 Sly 9,700 500 10,200 1,187 417 1,134 0.567 0.520 2,032 603 Poor 2 2.500 3,000 10 0 Sl, 1 19,400 2,000 21,400 2,280 2,000 2,250 0.855 0.75 1.959 290 Poor 2 500 8 000 10 62 21% 14,100 3,700 17,800 2,120 1,590 1,978 0.79 0.66 2 025 300 Good 14 2,000 3,000 105 0) 9 1. 26,100 1,000 21,100 2,23 2,000 2,221 O.S87 0.74 2.129 315 Poor 2500 5000 100 vA 13% 16,100 2,600 18,700 2,080 1,485 1,970 0.789 0.658 1,200 800 Good (ar 1050 102 63 1% 8.800 2,400 11,200 1,320 1,310 1,320 0.38 0.326 3.759 125 No force to b'ow 500 $050 99 0 6% 1% 10,000 1,400 11,400 1,600 934 1,470 0.42 0.363 4,500 150 Good X 3.500 1.050 10 A 2% 8.800 2,400 11,200 1,530 875 1,320 0.38 0.326 3,759 125 Good 19 6,000 7.100 101 } 6% 9 21.800 4,900 26,700 3,360 2,450 3140 0.525 0.443 4,000 121 Fair 0) 6.000 7,100 98 o 7% 1% 24,000 2,400 26,400 3,350 2,060 3,150 0.63 0.457 5.180 157 Good l 12,000 14,200 98 614 31 31.300 8,400 39,700 5.080 2,655 4.260 0.3855 0.300 15,600 240 Poor Le 12,000 14,200 100 6 30,100 300 30,400 4,880 1.800 4.810 0.403 0.341 19,175 295 Good 23 12,000 14,200 98 0-5 2% 20 5,700 1,800 7,500 2,360 863 1,665 0.138 0,117 5,850 90 Good $ 12.000 14.200 101 0-5 54 314 12,900 3,600 16,500 2,385 1,080 1,886 0.157 0.133 11,700 180 Fair NOTE In Test No. 16, the control valve was almost closed, so that enough steam could not be admitted to give force the blows meters between 2 and 5 per cent low. The flowmeters Lb. Steam per Average Working Hour were thus assumed to be substantially correct. Both Total Steam, Working Hours steam lines had eight right angle turns in the piping Total Working Hours between the meter and the first hammer; this, in addi- Lb. Steam per Average Idle Hour tion to the diversity factor of hammer operation, tended __ Total Steam, Idle Hours to smooth out the pulsations. : Total Idle Hours Cooling Water. For testing hammers of large ca- Lb. § A H Total Steam . : , , . : 40. Steam per Average Hour = ————_____.. yacity an ample supply of cold water for condensing . 2 pacity an am] pply é 2 Total Hours Lb. Steam per Hour per Lb. Nominal Falling Weight Condenser Surface Necessary for Various Sizes of Hammers Total Steam Size Condenser Cooling —=— — ——————<——————— Hammer Lb. Steam Surface Water, Gal Total Hours * Nominal Falling Weight Lb Per Hr. Required per Min . re P 1000 2000 80 sa. ft 45 Lb. Steam per Hour per Lb. Actual Falling Weight 1500 2000 80 sq. ft. 45 Total Steam 2000 2100 84 sq. ft 47 Do —— 2500 2200 88 sq. ft. 50 Total Hours * Actual Falling Weight 3500 2600 104 sq. ft 60 6000 3400 136 sq. ft. 77 vy 12000 10000 400 sq. ft. 250 Testing of Hammers NoTe.—The above assumes that hammers are in poor . eo i ie ae condition, wrought iron condenser piping is to be used, and During the early stages, it 1S best to select a ham 65 deg. Fahr. cooling water is available mer of lower rating, for then the testing equipment can purposes is important. With hammers in poor condi- tion the steam is discharged for a few seconds in large amounts, thus calling for a condenser of large capacity and water of adequate amount. The accompanying be given a thorough try-out and the necessary pro- visions made for the testing of the larger hammers. The first test is of course to measure the steam con- sumption of the hammer under operating conditions. Test results should be obtained during idle and work- June 9, 1921 ing hours, attention being given to steam pressures and number of blows per forging. Data should also be ob- tained on the actual weight of falling parts of the ham- mer, production in pounds of forgings during test and average weight per forging. After the first test is completed, the hammer should be inspected and, if necessary, valve adjustments made, stuffing box repacked and any leaks corrected. When the hammer is thought to be in first-class shape, an- other steam consumption test may be made and the differences between the two tests can be noted. While the repair crew is being educated as to what repairs are necessary, some experimental work can be done, particularly as regards valve setting, until a point is reached where the hammer has a minimum steam con- sumption, consistent with proper operation. During the progress of the individual tests, total steam consumption readings, by means of steam flow- meters, can be taken on the steam as fed to the entire forge plant. This steam consumption, as compared to forge productions of individual hammers revised for working and idle hours operation, will show imme- diately the results of any reductions in the steam con- sumption for the entire forge plant. Setting of Valves Proper setting of the actuating valves is the most important feature in reducing the steam consumption, for the economy of the hammer suffers very materially when the valves are improperly set. Referring to the diagrams of valve settings, it has been the writers’ experience that the best efficiency will be obtained by setting the actuating valve, when the ram is at top of stroke, so that the steam inlet is 1/32 in. and the ex- haust clearance 1/16 in. This is illustrated, as is also a faulty valve setting that has been frequently found, where the hammer man was complaining that his ham- mer lacked force in its blows. After his valves were properly set, no further trouble was experienced in producing forgings quickly. With greater clearance in the inlet and exhaust sides than given above, the steam consumption of the hammers, when standing idle, is often greater than when the hammer is working and producing forgings. As an illustration, the steam consumption of a 12,000-lb. tandards for Various Types of Hammers in Good Operating Condition* Nominal Working Period, Idle Period Falling Lb. of Steam Lb. of Steam Weight, Lb per Hr per Hr 1000 1100 500 1500 1200 500 2000 1300 500 2500 1400 1000 3500 1600 1000 6000 2200 1000 12000 3000 600 *As determined by actual tests. hammer that was tested was found to be at the rate of 5000 lb. per hr., during idle periods; while another hammer of the same size, working on the same class f forgings, consumed 3000 Ib. per hr. while working ind 600 lb. per hr. when idle. The first hammer wasted team at the rate of 4400 lb. per idle hour, or at a fuel cost of $2.60 per hr. Continuous Testing of Hammers By having steam flowmeters on the main supply nes to the forging plant, daily readings can be ob- ined which show the plant economy. To take into msideration variations in production, it is necessary establish, by the individual tests, the steam consump- on for all classes of hammers, per working hour and per idle hour. Then the record of the idle and work- ng hours, multiplied by the steam consumption stand- rds for each, and the grand total compared with flow- eter readings, will show the condition of the ham- THE IRON AGE : 1525 mers. If the flowmeter readings are in excess, the hammer economy is poor and the steam consumption is in excess of the standards. In the above standards, the ram was at top stroke during the idle hours with the exception of the 2500, the 3500 and the 6000-lb. hammers, which were oscillat- ing. The standard cut-off for all hammers tested’ was 40 per cent. Back Pressure on Hammers Most forge plants operate with back pressure in the steam exhaust Experienced hammer men claim that there is a cushioning effect, due to this back pres- sure, which helps produce better forgings. lines. Neglecting the increase in steam consumption, this is a distinct advantage, so that the exhaust can be used for heating or other purposes. About 5 lb, standard. back pressure is the Auxiliary Exhaust Lines As the exhaust from the cylinders of the hammers usually ties into a main exhaust header, there is no means of inspecting individual exhausts if auxiliary exhausts are not provided. If these additional exhaust so that the steam can be, for a short time, exhausted direct to the atmosphere, a means of inspecting the condition of the Inspection can be lines are piped in, hammer is available. made during working and idle times, and after observing the exhaust of a hammer in good condition, experience will show need of valve setting or repairs to valves, cylinder or piston. exhaust These auxiliary lines will decrease the amount of testing by condensation and will measurements, be a guide for the repair crews. Recapitulation of Test Data To make a fair comparison of the tests, one should take into consideration the type, the number and the weight of the made, versus the total consumption and the total working hours. For exam- ple, take tests No. 1 and No. 2 on a 1000-lb. hammer making the same class of forgings. Test No. 1 shows a steam consumption of 1074 lb. per hour with 38.4 forgings per hour; while test No. 2, on the same ham- mer after overhauling, shows 930 lb. of steam and 57.4 forgings steam forgings per hour. 4 and 5, 8 and 9, 12 and 13, ) and 22, can be Tests numbers 17, 19 and 20, 21 in the same way, as they were run under similar condi 16 and paired and compared tions. This is shown graphically on one diagram, where the steam consumption per pound of forgings for the different types of hammers is given. A movement to expedite public work to afford em- ployment to large numbers of idle workmen has been started at Youngstown, Ohio. It is estimated fully 20,000 men are idle due to stagnation in the iron and steel industry, and consequent reduced operations. In spite of the large volume of unemployment, there has not been a proportionate increase in the demand on charitable organizations, as families of steel workers are living on earnings accumulated during the war. Many of these men, temporarily out of employment, are glad to get work on highways at 30c. per hour. The American Steel Rolling Co., 1203 North Charles Street, Baltimore, has preliminary plans under way for the erection of a new plant at Monument and Eighth Street, for the manufacture of iron and steel rods, reinforcing bars and kindred products. It is proposed to establish an initial output of about 15,000 tons per annum. W. Y. Schall is superintendent in charge; Reuben S. Baldwin is general manager. Foundry laborers in Belleville, Ill., who have been on a strike for several weeks, have voted to accept the proposition of employers, providing for a wage of 47c per hr. to be effective until Dec. 31, 1921. The previous wage was 55c per hr. 1526 , Engine Building in the United States Steam, gas and other engines built in 371 plants in the United States in 1919 accounted for a product of $464,770,000, according to a bulleting of the Census Bureau. This represents an increase of 544.4 per cent over the $72,121,000 reported for 1914. Some of the outstanding features of the bulletin follow: As 1919 prices differed materially from those preva- ent in 1914, the bare statement of dollars of output foes not provide a true picture of the advance of the ndustry. Department of Labor figures show that, with 1913 as a basis at 100, prices in the group of “Metals and Metal Products” averaged 87 in 1914 and 161 in 1919. Translating 1919 figures into 1914 prices on this basis (which, perhaps, will not apply exactly for engines, but may be regarded as a fair approxima- tion) the 1919 output of the industry appears to have Value of Steam engines* Products 1914 $5,402,000 Steam turbines* 3,689,000 Marine engines§ 338,000 Marine turbines$ : re Total steam engines? 9,429,000 20,648,000 10,122,000 Gas and gasoline engines*....... \utomobile and aviation engines? Marine gasoline engines§....... 6,426,000 Total internal combustion; 37,696,000 Traction engines! 4,209,000 *Stationary and **Not separately cluding engines made in n plants whose chief product was ships or boats. portable. Sevennendananneneeeeaoentenneepneunanagyen been about $251,000,000 in 1914 dollars—an advance of 248.5 per cent over 1914, instead of 544.4 per cent. Similarly equated figures are shown for details of the output in the table. Railroad Wages Reduced The United States Railroad Labor Board announced an average wage reduction of 12 per cent at Chicago on June 1. The wage cut, which becomes effective on July 1, will reduce the pay of railroad employees about $400,000,000 per year. The decision affects 104 roads requests for reductions had been filed since April 18, when the hearings before the board com- menced. Eventually the reduction will apply to all lines and those which have not yet filed their applica- tions will present their cases during the current month. The decision establishes new uniform scales for all groups of employees from track laborers to enginemen and conductors and instructs each road to apply the new scales to the special classes for which it had asked reductions. Some lines thus far have asked for cuts in the wages of common labor only, while others have included other classes of employees, and a few have asked for reductions for all employees. It is therefore apparent that before the full effect of the reductions is felt, further applications must be filed with the board by the various carriers. When all of the new schedules have been applied to all of the lines, the total railroad payroll will be reduced $400,000,000 a year. Thus the cut does not wipe out the advance of $600,000,- 000 authorized by the board on May 1, 1920. whose Higher Salaries Necessary WASHINGTON, June 7.—Material increases in the salaries of technical and scientific employees of the Government are necessary in order to prevent whole- sale resignations in the various scientific bureaus. This opinion has been expressed to the joint Congres- sional committee, considering reclassification of federal employees and bureaus, by A. T. Koehler, secretary of the Federal Council of the American Association of Engineers. In substance, a similar view was stated by a number of scientific and technical employees of the Government. The latter are supporting the Ster- ling-Lehlbach in preference to the Smoot-Wood mea- THE IRON reported in 1914. plants whose chief product was automobiles or aircraft. {Not including locomotives. AGE June 9, 1921 sure. Support of the Sterling-Lehlbach measure | Government employees is based on the claim that provides a real classification, while the Smoot-Woo measure, they say, calls for only a mere change of pa and is in no sense a reclassification and would simp! mean a continuation of the same injustices and j) equalities now existing. The Federal Council of th American Association of -Engineers presented schedule of salaries it deems necessary to keep up th morale and efficiency of the various bureaus, statin, that unless some such action is taken the Government will lose, within a few months many of its valuab|: technical employees. Many recommendations are mad by the council which, if adopted, it claims, will meet the approval of the profession at large as well as th technical and scientific employees of the Government. The council does not give full approval of either of th. pending measures. It states that its recommendation HULUUHELELUEERUDUEELEDUOEEEOERRECUAAUOONND UNAEDONNE AMRELOMEREENENE -—Figures as Reported On Basis of 1914 Prices Per Cent Per Ce 1919 Increase 1919 Paseceae $7,617,000 41.0 $4,116,000 24d 9,837,000 166.7 5,316,000 44 23,332,000 6803.0 12,610,000 3631 28,217,000 diate 15,250,000 ee 72,047,000 664.2 38,939,000 813 48,941,000 137.0 26,449,000 28 71,733,000 608.7 38,768,000 283 19,153,000 198.1 10,350,000 61 141,709,000 275.9 76,585,000 103 124,546,000 2859.0 67,305,000 1499 fIncludes minor items not listed. {Not in- §Not including engines made d Decrease, sey ' 1 DOPSUENNHONOEPODNNHDO NONE DONO ODOOODEDOOOHOPOONOOUENUREDUNECAONEEDREENOOENTORONNEOOESHOONND none for increased salaries will provide more equitable com- pensation, permitting allocation of an employee at the minimum, maximum or intermediate salary of a given grade, according to merit. It also suggests that it be- lieves it essential that any bill which is brought into operation shall contain provisions for an executive agency under the control of the President, to harmonize all questions regarding allocation and which shall func- tion as a board of appeal for the employees. Immigration Under New Law WASHINGTON, June 7.—Immigrants to the number of approximately 360,000 will be admitted to the United States during the fiscal year, beginning July 1, under the Dillingham percentage immigration law. The number by countries was announced last week by Commissioner of Immigration W. W. Husband. Unde the new law the allotment of immigration is based upon 3 per cent of the number of immigrants from given countries in the United States in 1910. Th largest number to be permitted will be 77,206 from th: United Kingdom, with Germany ranking second, with 68,039. Some of the other important countries and the number of immigrants permissible are: Norway, 12,116; Sweden, 19,956; Denmark, 5644; Poland wit! Western Galicia, 25,800; Switzerland, 3745; Italy, 42,021; Russia, 34,247; Austria, 7444; Hungary, 5635; Rumania, 7414; Greece, 2286; Czecho-Slovakia, 14,269 and Jugoslavia, 6405. SE Not Promoting Socialism WASHINGTON, June 7.—That the International La- bor office is not “a laboratory for the manufacture of a particular brand of ‘social’ or ‘socialist’ doctrines, and that it has not “entered into direct relations wit! trade unions and other workers’ organizations instead of keeping its activities within the limits which woul be imposed upon them were they to confine their rela tions to Government departments only,” is the unan'- mous opinion of the commission of experts appointed by the Council of the League of Nations in accordant with a resolution adopted by the Assembly of the League at its meeting of Dec. 17, 1920. A summar) of the findings of the commission was made public yes- terday by Ernest Greenwood, American correspondent of the International Labor office. Design and Proportions of Hot Blast Stoves’ Consideration of Laws Governing Cir- culation of Gases While Heating and Cooling—Historical Designs Reviewed BY W. E. GROUME-GRJIMAILO+ ——~ ° N 1860 Cowper applied the regenerative principles of Siemens to the heating of the air for blowing blast furnaces. But at first these hot blast stoves were not a success. In his Manual of Metallurgy, Percy-Wedding shows some of the early designs of hot blast stoves, one of which appears in Fig. 1. The first Fig. 1 Early De- sign of Hot Blast Stove Fired with Coal or Coke In this and subsequent figures the flow of iir is shown by a dotted arrow: the flow of products of combustion, by a solid arrow stoves were heated with coal fires; the gas from the blast furnace was not utilized until later.t. The hot products of combustion from the fire flowed direétly up- ward and to the top of the stove and passed out of the structure through a primitive chimney valve in the dome. The cold blast entered the apparatus at the top and the hot blast valve was connected to the lower part f the stove. It may be readily seen that the currents Fig. 2 Two Forms of Cowper's Later De- signs of Two-Pass Side Combustion Chamber Stove, Showing Correct Method of Air Circu- lation In one the arch is pierced by an orifice so proportioned that combustion will be completed within the side combustion chamber f gas and air in this apparatus were circulated in the vrong directions—that is, in the opposite direction to the natural convection currents. *Copyright, 1921, by A. D. Williams +Professor of iron manufacture at the Polytechnic Insti- te of Petrograd. The translation is by A. D. Williams. Note by translator: The early blast furnaces were simple en-topped shafts without any bell or hopper, the gas burn- at the head of the furnace. The blast pressure was very The charging was elementary; in many cases the top the furnace was reached by an inclined plane up which charge was carted in simple dump-carts, which were cked up to the open shaft and dumped the charge into it ter, when the bell and hopper were utilized to close the of the furnace, the gas became available for heating the st and making steam The name, hot blast stove, is a sur- val from the early coal fired stove Cowper perceived the erroneous method of gas cil culation in his early design, and in later designs the currents of gas and air were circulated in the correct direction (Fig. 2). Combustion took place in a central or eccentrically placed chamber, the hot gases rising to the dome, where they were reversed and subdivided among a number of parallel passes down through th checkerwork, and uniting in a lower chamber they wer: carried away through the chimney valve. The col blast enters the stove chamber below the checkerwork, through which it passes upward in a number of paralle! streams to the dome of the stove, where it changes di rection and passes downward through the combustion chamber to the hot blast valve. The Cowper hot blast stove retains this general arrangement to the present day. It would be difficult to find any apparatus which has passed through as many modifications of design-as have these stoves; but few of the changes. have com into extended use, because practically all of them have been based upon an entirely false idea in regard to th laws governing the circulation of gases while heating =<" | - a f Hot Air and cooling. The single weak point of the Cowper hot blast stove lies in the location of the combustion cham ber, which in the form of a vertical tube or chamber occupies a large amount of space and is poorly adapted for the purpose for which it is employed. The at tempts to improve the design of these stoves should be directed toward the elimination of this tube from the combustion chamber. The space located immediately below the dome of the stove might be employed for a combustion chamber, as is suggested further on in this article. Moore’s patent (Fig. 3) shows such a single pass construction, but it is badly worked out. In Moore’s stove the hot gases of combustion pass upward, in the opposite direction to their natural convectior currents. Withwell made the first modification of the Cowper stove. The experiment shown in Fig. 4 illustrates the defect of the Withwell stove. Two designs of stove were photographed, immersed in a glass tank filled with water, Withwell’s design on the left and the Cowper design on the right, during the period when they are upon gas, or heating. The uniform level of the lower surfaces of the colored kerosene forced downwarid through the checker passes of the Cowper stove illus trates the regularity of the heating of its checkerwork. On the other hand, in the Withwell stove, the chambers 1527 ave cone sees Fig. 4 Experiment Showing the Defect in the Withwell Stove, at the Left, Compared with the Cowper Stove, at the Right. The latter is heated uniformly, the former is not are filled with the colored kerosene in a manner which is far from uniform. The chambers through which the kerosene descends are completely filled, while those in which it rises are not filled at all; the kerosene rising in a thread-like stream which comes into contact with a very small portion of the wall area of the chamber. These chambers, therefore, uniformly heated, and for this reason will impart very little heat to the air. If water is introduced at the lower part of the model, representing the cold blast which is being heated, it that those chambers through which the water rises fill perfectly, while in those in which the it falls in small will not be will be seen water passes downward, Fig. 5 Later Dk sign of the With well Hot Blast Stove | ' | | | ; streams which have very little contact with the walls of the chamber. A mere glance at fhese models is suffi- cient to show clearly the reasons which have led to the complete abandonment of the Withwell stove. Withwell noted the defects in his own stove and in a later design (Fig. 5) he gave the hot gases a circu- lation in the proper direction, from top to bottom. This design of his stove approximates the type of regenera- tor shown in Fig. 23 in the article “Design of Open- Hearth Furnaces,” page 1510, THE IRON AGE, May 27, THE IRON AGE June 9, 192) 1920. The ideas of Withwell have found their realiza tion in the Massick and Crook stove, which had quite name at one time, and which was distinguished fro: the Withwell stove only by the arrangement of th passes, so that the gases traveled alternately up ani down through the three passes. In practice the Massi: and Crook stove has been superseded for which will be clearly evident. reasor Juggling Heating Surface and Pass Areas When methods of arranging the checkerwork heat ing surface and passes are considered, many invento! have applied themselves to the problem of securing un formity in its working. apparently without the slightes! suspicion that the regular and uniform descent of th hot gases in cooling is a natural property of the gases For a time the design of stove patented by Becker (Fig 6) was much favored; the openings in the checkerwork were given different dimensions. It is evident that this will result in a less uniform heating than will be secured in the ordinary design of the Cowper stove. This Beck- er design has less frictional resistance in the openings than there will be in the small, accordingly th: waste gases from the large passes will be hotter than the gases from the smaller passes. In the model (Fig. 4) of the Cowper stove, the cros section was intentionally made with checker openings of several sizes, in order to show, in graphic manner, that such complications of the checkerwork are useless. To insure a uniform distribution of the hot gases through the checkerwork, J. Z. Stephenson and J. Evans resorted to a series of complicated walls and dampers in the chamber below the checkers (Fig. 7). The discussion larg " 7 ~~ 4 >> oS jf ia J Apr, Fig. 6 Becker's Hot Blast Stove Section Show ing Arrange ment of Checl ers in Thre: Groups—Figures Indicate Sizes of Passes between Luhrmann and these inventors in the technical! journals is mentioned merely as a matter of interest Luhrmann contended that the largest portion of th waste gases passed through the section above A and the smallest portion passed through the section above C. Th« inventors claimed the contrary. This discussion made it clearly apparent that the ideas of contemporary ¢o! structors, in regard to the circulation of the gases, wert most remarkably confused, but the quarrel: was finall) settled to the satisfaction of both parties. In the Cowper stove, the work of the checkerwork inherently uniform, and all walls and dampers below th« checkers, for the purpose of distributing the gases, ar‘ superfluous. In the Revue de Métallurgie, February, 1913, page 362, can be found the designs of a Cowpe stove built for the blast furnace at Caen, France, anc provided with five chimney valves connecting the cham ber below the checkerwork with a bustle pipe outside th stove. The idea, of course, was that this would conduc to the uniform distribution of the gases heating thé checker work. This idea in many ways, resembles tha‘ of Stephenson and Evans, but the multiplication of th’ chimney valves is useless. It would be sufficient to re place them by a single valve whose dimensions may computed by the formula of Yesmann. June 9, 1921 The number of designs of hot blast stoves in which the attempt is made to circulate the hot gases in cooling, and the cold gases in heating, in directions contrary to their natural convection currents is very large. The de- sign sketches of Hartmann (Fig. 8), Hugh Kennedy (Fig. 9), Macco (Fig. 10), Frank Roberts (Fig. 11), Harvey (Fig. 12), show that the laws governing the sub- Fig. 7 and Hot to Regulate the Stephenson Evans Blast Stove, with Dampers Distribution of the Gases livision of currents of hot gases while cooling, and cold vases while heating, are not very well understood at the present time. Construction of the Combustion Chamber In the statements which follow, the attempt has been made to show the rational location of the combustion ‘hamber for a hot blast stove. For this reason it is nec- essary to digress slightly at this point in order to set forth the rational chamber necessary for ‘ombustion. If a flame or jet of burning gases, in which the reac- tion of combustion has not been completed, is directed nto a cold chamber or upon cold objects, combustion conditions Fig Ss Hart mann Design of Hot Blast Stove Cold Air | ee will not be completed even in the presence of an enor- nous excess of air. Theoretical combustion, without an excess of air, can be obtained only when the reactions f combustion are completed in a chamber where the flame is surrounded by incandescent walls and within which it is held during one or two seconds. The con- struction of the combustion chamber must be such that is possible to hold the flaming gases in the chamber 1 predetermined length of time, and in which the walls if the chamber will be heated to the highest possible ‘temperature. How should the flame of reacting gases be brought nto the combustion chamber? In the Cowper stove (Fig. 2), the combustion cham- er forms a cylindrical or elliptical opening extending the full height of the stove, and open into the space elow the dome at its upper end. Guilow, in an article in Revue de la Société russe de Métallurgie, 1911, page 164, gives the volume of the different portions of a THE IRON AGE 1529 Cowper hot blast stove at the Kouchwa works, and the time of the gas in these portions, as follows: Volume, Volume, Cubic Cubic Time, Meters Feet Seconds Combustion chamber ........ 14.53 513.1 4.60 Dome of stove.... 6.16 217.5 1.77 Checkerwork openings — sl 1497.3 16.96 Chamber below the checkerwork 5.14 181.5 5.14 Totals 68.23 2409.4 28.47 Note by translator: It is interesting to compare these volumes with the volumes of hot blast stoves given in a paper by Arthur J. Boynton, National Tube Co.,. Lorain Ohio, before the October, 1916, meeting of the American Iron and Steel Institute The Russian furnace is undoubtedly much smaller than the American furnaces Though the volume of the Cowper combustion cham- Waste Gases \ Cold Mir « y ’ =] Fig. 9 (at Left) Hugh Kennedy Design of Hot Blast Stove Fig 1) (Cat Right) Macco Hot Blast Stove ber is very large, it does not function satisfactorily, be- cause the streams of flaming gases have a very high temperature and a correspondingly slight density. For these reasons they rise rapidly, and leave the combus- tion without encountering any obstruction flowing into the space below the dome. Hence the column of flaming gases, rising without filling chamber to delay them Ho Fig. 11 Frank Roberts Design of Hot Blast Stove Fig. 12. Blast Stove Harvey Hot 1530 the combustion chamber, passes through a surrounding atmosphere of unburned and relatively colder gases. Direct observation of the combustion of blast fur- nace gas in the Cowper hot blast stove shows that, as the ratio between the gas and the air supply approaches the theoretical requirements, combustion ceases to te silent and becomes noisy. The flame commences to jet out around the gas burner in bursts, indicating tem- Fig. 13. Imprope Arrangement of Burner for One- Pass Stove with Top Combustion Chamber porary extinguishing of the flame in the combustion chamber, which immediately fills with a comparatively cold explosive mixture. Location of Combustion Chamber Everything indicates that the correct location for the combustion chamber of the Cowper stove is the dome or space above the checkerwork. The streams of flame which are produced cannot pass directly out of this chamber, but are held under the dome, heating its walls from below. The dome forms a permanent firebox for their combustion. Below the dome of the Cowper stove, therefore, there is a stationary hot zone, which burns the portions of the gases which were not utilized in the combustion chamber, as soon as they come into contact with the heated chamber. For these reasons the con- struction of a Cowper stove with the combustion cham- ber located elgew! cre than in the dome is fundamentally wrong. However, if the gas and the air are simply intro- Fig. 14. of Burners Arrangement Suggested by Author for Pass Hot B One- ast Stove duced above the checkerwork of the stove, as in Fig. 13, there is the danger that a portion of the cold gas and air, in place of entering into the reaction of combustion and forming a flame, will drop down to the bottom of the stove, through the checker openings, in the same way in which a heavy liquid will sink downward through a light liquid. To prevent this phenomenon, which is undesirable and wasteful, it is useful to direct the currents of gas and the cold air for their combus- tion upward toward the dome of the stove, and to give the combustion chamber an arrangement similar tv that shown in Fig. 14. There are many advantages in constructing a hot blast stove in this manner. In the Cowper type the com- THE IRON AGE June 9, 192) bustion chamber actually occupies nearly 35 per cent of the space inside of the shell, and causes an unnécessary increase of nearly 50 per cent in the cost of the stove The analysis of this particular case of combustion chamber construction permits the following rules to be deduced fof their arrangement: 1. The jet of flame in the chamber should not be di- rected horizontally; 2. The streams or jets of gas and air entering the chamber should be, where possible, directed upward toward the dome or roof; 3. The products of combustion should be carried away from the combustion chamber at the hearth level, in either a vertical or a horizontal direction, as shown in Fig. 15. Nevertheless, it is sometimes necessary that a verti- cal combustion chamber should be used. In this case it is not necessary to repeat the error made by Cowper and construct the chamber as an open pit (Fig. 2). It can be covered by an arch pierced by one or more open- ings, whose total area may be arrived at by the use of the formula for furnaces having an orifice in their roof for the escape of the waste gases, as given in an earlier chapter of this work. If the area of these orifices and the volume of the combustion chamber are correctly proportioned, the combustion pits of the Cowper stove will be completely Fig. 15, Two Alternative Methods of Carrying Products of Combustion Away from the Combus- tion Chamber filled with the burning gases, which will be held in the combustion chamber, by reason of the strangulated out- let, until the reaction of combustion is completed. The free space bel