MR. W. H. FITCH.-The remark was made about three or four weeks ago that one could not melt steel in an openhearth furnace and iron in an air furnace successfully with pulverized coal, and as the gentleman in question is an engineer engaged in building plants and advising accordingly, I think those who know differently ought to combat it. We are melting iron successfully today in the plants of one of our clients and have melted steel in open-hearth furnaces over a period of four years. I think that means that it is practical, to say the least.

Some months ago one of the malleable companies wanted a modern pulverizing plant to operate a battery of annealing ovens. Eventually the question of melting iron with pulverized coal came up and we applied it to one of the air furnaces. That furnace is in service now producing 30 per cent more now than when it was hand fired. The quality of the iron is first class, and all the labor used in hand firing has been eliminated.

We took the grate bars out of the furnace and made it similar to an open-hearth furnace above the floor level, obtaining 18 tons per heat where before we got about 13 maximum. The complete cycle is made in about two hours less time than with hand firing, producing about 36 tons in the two heats. The average fuel ratio is 42 to 1. We have got as high as 4.87 pounds of iron to a pound of coal.

The condition of the refractories is first class; in fact, better than they were when the coal was hand fired. The saving on the brick work compared with hand firing is not known definitely but is estimated to represent several hundred dollars per annum.

There is no particular difference between this furnace and hand fired furnaces, except that the grate bars are removed, increasing the hearth area. There are two burners on the furnace in which the coal is thoroughly mixed, the combustion air is added and then projected into the furnace. One can rest his hand on the burner as it is cool at all times. The furnace is about 250 feet from the line which serves the large muffle

furnaces. Coal is pumped to the pulverized coal bin at the melting furnace through a 312-inch wrought iron pipe in much the same manner as water is handled, so far as velocity is concerned.

MR. FITCH.-I have just been requested to say a few words about mixing coal dust with fuel oil. During the war the government called upon us to do some work in this connection as applied to steaming. For several months a steamer was operated on Long Island sound in making these experiments. Different mixtures of oil and coal dust were made and applied successfully. As high as 80 per cent of coal dust in a gallon of oil was reached and there were no detrimental effects.

For any one of those who contemplate the use of different kinds of fuels I think that it is merely a question of how much heat can be obtained for a dollar.

MR. ENRIQUE TOUCEDA.-I think Mr. Arrowood is in error in thinking he can reduce the annealing time to 18 hours. A certain length of time is required to bring castings up to temperature, while they cannot be held at temperature for much less than 48 hours in commercial practice. Also, the castings should not be cooled from temperature at a rate less than 10 degrees per hour. There seems to be a tendency in the industry to endeavor to shorten the anneal, and it is doing a great deal of harm. I believe that we should fight any such propaganda as that, because I think the attempt is absolutely in the wrong direction.

Now in connection with the quick heating of the oven to temperature, there are practical propositions to consider which if taken into account will cause trouble. For instance, if an oven is heated to temperature in 15 hours, the rings will expand more quickly than the contents within it, because the heat cannot be absorbed by the contents as fast as by the metal in the ring; the result is that as the rings expand the packing will bleed from the upper ones to those lower down, and in extreme cases the castings in the topmost ring will be found to be unprotected by packing.

A MEMBER. There are representatives here from the Malleable Casting Co. I should like to hear what they have to say

as I understand the company now is melting with powdered coal.

MR. A. J. GRINDLE.-At a recent installation we had 19 successful heats and no bad ones. Every heat was hot and each took a little shorter time than the preceding one. The first took 7 hours 45 minutes to melt. Last Thursday afternoon we ran the second heat in a small furnace, the maximum capacity of which was 10 tons. The furnace was only 5 feet wide inside and 152 feet long between bridge walls, so that it is not fair to compare this furnace with a large one which can melt 12 or possibly 25 tons. On the first heat on the last runs we melted a heat in 4 hours 25 minutes, ready to tap. It took an hour and five minutes to take the heat out of the furnace on account of the small number of molders around the furnace. We melted 8.142 tons of metal with approximately 590 pounds of coal per ton. The percentage of pig iron was 43. The melt per hour was 1.48 tons. The carbon was 2.44 per cent, silicon, 0.92; sulphur, 0.094; and manganese, 0.28. We thought when we started the furnace that we were likely to pick up the sulphur; therefore we built the furnace extra high so that we could get good combustion before we heated the metal. We find it runs about 0.01 lower. On the first heat on the next day we melted 9.29 tons in 5 hours 25 minutes. The total time on that heat. was 6 hours and 10 minutes until the heat was out. We had 41 per cent pig iron on the start and at one time were down as low as 35 per cent pig, but we found it advisable to change our furnace. The furnace is equipped so that we can fire coal in the top blast, and we decided to take the coal off the top and use only air here. We threw ourselves back about a week on the results that we had been getting, but we found when the top blast was on the pig iron went up. These results were obtained when using air and no coal on the top. The coal we were using analyzed moisture, 2; volatile, 37.43; fixed carbon, 54.98; and ash, 5.9 per cent. The sulphur was 0.768 and the British thermal unit value, 13,605. The sieve test was: Two hundred mesh, 84 per cent; 240 mesh, 80 per cent, and through 300 mesh, 56 per cent.

Melting in An Air Furnace with

Fuel Oil

By J. P. PERO, East St. Louis, Ill.

I have been unable to find any literature bearing upon the use of fuel oil in air furnace practice. For some reason unknown to me very few have tried or at least adopted oil as a fuel in air furnace melting. I have tried to get in touch with everybody using oil for this purpose in order to present the subject as thoroughly as possible, but have been able to get data from but two malleable iron foundries. The facts presented in this paper embody not only my personal experience but in its essentials describe the practice of two other malleable iron manufacturers who have been very successful in the use of fuel oil in air furnace practice.

For a number of years I considered the advisability of using oil for melting, but was unable to get any information to assist me in the various details of furnace construction and operation, until about three years ago I learned that the Iowa Malleable Iron Co., Fairfield, Iowa, was working along these lines and partly by collaborating with this concern and partly by the adoption of my own ideas, and by much experiment I succeeded in producing most excellent results in every essential except in economy of fuel cost, which item is really relative and is governed by the comparative cost of coal and oil in any given locality. Unfortunately, the relative cost of the two fuels in my plant was such that the actual fuel cost of coal was the cheaper of the two. With a knowledge of the relative cost of oil and coal in your locality, you can from the data given in this article readily determine which of the two fuels will be most satisfactory. There are several features other than economy of fuel cost that should be given consideration in choosing between the use of coal and oil, and my opinion is that in prac

tically every essential feature of furnace practice other than the cost of fuel, oil is unquestionably preferable to coal.

Few Disadvantages

The only disadvantages I have found in the use of oil as compared with coal is the increased cost of the fuel itself, which item will vary in different localities according to the distance from the sources of supply of the different fuels; for instance in a locality having a long haul on coal and a short haul on oil, the difference in fuel cost per ton of iron melted might be negligible.

As an example, the Jewell Steel & Malleable Iron Co., in its San Francisco plant, found that oil with a consumption of 65 to 66 gallons per ton of iron melted in a cold furnace was not only very much preferable to coal but absolutely cheaper, due to the fact that coal is abnormally high priced on the Pacific coast on account of an extremely long haul while oil was delivered on a very short haul. In my plant I found the fuel cost per ton of iron melted by oil nearly double the cost with coal.

In addition to the increased cost of fuel, the only disadvantage I have found in the use of oil is excessive oxidation of the carbon, silicon and manganese contents. Just at this time when we are paying a premium on pig iron with a high silicon content, this feature is a disadvantage. On the other hand the absorption of sulphur is so slight in using oil that it is possible to use a high sulphur iron which can always be bought at less than market price for standard grade.

Among the many advantages in the use of oil are positive control of the melting, rapid melting, much lessened cost of furnace repairs, absence of cinders, reduction of the furnace gang to one man and economy in coal handling. There are many minor advantages. I have named only the principal ones.

In controlling the melting of the heat, without effort other than the opening or closing an oil valve, or the admission of more or less air from the blast, the melter can bring about almost any results he desires. I have seen a heat of 14 tons in a melting chamber 21 feet 6 inches long and 6 feet wide solidify after having been