7650 Banks St. Justice, Illinois 60458
Many times, I am asked, 'What's the, horsepower of my boiler?' I want to tell them, I don't know, and really I don't know. I ran my first rig in 1932, a boy of 12 years old. Since then I have seen steam power used for just about everything except flying of airplanes and to run submarines, and it is possible they could do that. I've seen them grade roads, pull tumble bug scrapers large enough to make a D8 cat grunt and strain. I've seen 22 hp. steam rigs crush stone as fast as dump trucks could haul it up and dump it in the hopper. In 1955 I saw a 16 hp. steam rig pump water 24 hrs. each day, 6 days a week for 7 weeks. The 75 hp. electric motor was sent back to the manufacturer for repairs. I have studied the situation for many years and haven't got a correct answer. A well known maker of engineering specialties came up with the following rules for calculating the horsepower of various kinds of boilers. These rules are intended for use in determining the proper size injectors and feed pumps etc.
KIND = HP.
Horizontal Tubular = Dia2 x Length 5
Vertical Tubular = Dia2 x Height 4
Flue Boilers = Dia x Length 3
Locomotive Type = Dia of waist2 x Length overall 6
All dimensions in feet, overall length is of tubes.
Vertical boilers, just the part under water.
Example Locomotive Type
Waist Dia 40' Length 14'
The heating surface 268
Manufacturer's Rating 25 hp.
Rating by Rule 25.9 hp.
Hold it a minute before you go out and measure the old gal's 'Vital Statistics.' Let's go back and review my first statements which I made of steam power exceeding its factory ratings. We know a cubic inch of water will make a cubic inch of water will make a cubic foot of steam. At this time I do not intend to go to a lot of details on this. But we must remember the fact, the more lbs. of steam per hour we make, the more power we have. The amount of steam depends on the amount of feed water, the type of fuel, and the method it is fed.
Wood is probably the most common fuel that has been used in the main years of steam power. First let's see what makes wood do the job.
The main idea to be shown is that the value of all wood is about the same in calorific value, depending on moisture contained. Now remember one thing. wood differs in weight. We find the values as follows:
Hickory & Hard Maple 4,5000 lbs. = 1,800 lbs. soft coal
White Oak 3,850 lbs. = 1,540 lbs. coal
Red & Black Oak 3,250 lbs. = 1,300 lbs. coal.
Poplar & Elm 2,350 lbs. = 940 lbs. coal.
Pine 2,000 lbs. = 800 lbs. coal
From this it is safe to say 2 pounds of dry wood is equal to 1 lb. of good soft coal.
At this time we will not go into lbs. of fuel per sq. ft. of grate. That is a subject for later. It seems as though I am skipping a lot of details; that's true, I am.
The average wood contains 51% carbons; 6.5% hydrogen and 42% oxygen. 1 lb. of wood is 8170 B.T.U. if proper combustion is permitted. The calorific value of 1 lb. of carbon = 14,500 B.T.U. 1 lb. of hydrogen = 62,000 B.T.U.
We must realize the smaller the fuel is, 'shall we say cut up,' the faster it is burned and the more lbs. per minute is consumed. Therefore skipping details again as usual, we find we can evaporate 3.95 pounds of water with 1 lb. of wood, 'evaporated from 212 degrees F' that is.
Now we go to a different situation when we go to coal. Most boilers are fired with Bituminous 'Soft coal,' because it breaks down faster and we get' the heat quicker. It contains a large amount of hydrogen and volatile matter ignites readily, burns with long yellow flame and produces a great deal of smoke, 'unless properly dealt with.' I agree with Mr. Alva Hulbert's March-April article 'I am Concerned.' So with this agreement, let's see what we can do about burning coal properly.
To burn coal we must have good combustion. Combustion is the union of the carbon and hydrogen of the fuel with oxygen. The oxygen conies from the air; approx. 20%. Each atom of carbon combines with two atoms of oxygen. 2.66 lbs. of oxygen are required for perfect combustion of 1 lb. of carbon which we get carbonic acid gas called carbon dioxide; prefix 'di' meaning 'two,' thus implying 2 atoms of oxygen, 1 carbon and as we said before, we get 14,500 units of heat per lb. If we do not get enough oxygen, we get carbon monoxide, prefix 'mon' meaning 'one.' That's toxic.
Carbon monoxide produces 4,400 units of heat. The sight of smoke 'does not necessarily mean air pollution.' We cannot say this until we analyze it. By admitting excess air to our combustion, we will get a cleaner burn, 'Like a black smith forge.'
As I said before Bituminous coal has a large amount of volatile matter which is thrown off as soon as it feels the heat. It flashes into flame as though it was sprinkled with petroleum. During this stage of combustion, a great deal of oxygen is required for so large amount of combustion gas, and it is difficult to get the oxygen in fast enough without cooling the gases below point of ignition.
In this case a slower method should be used, by firing one side of the furnace at a time, having always one side bright to maintain the temperature and ignite the gases distilled from fresh coal. This method reduces smoke and increases economy. Smoke is imperfect combustion.
Let us look at an act of combustion closely and see what does go on. I have found with experimenting, we get two separate explosions; first from the hydrogen, then the carbon. I will not, and cannot, advertize a product in any article I write, but I will say that myself and associates have patent on a product that is used for combustion; it is a catalyst. With this we find the atoms of hydrogen and carbon unite and ignite together. Therefore, we get 62,000 plus the 14,500 units of heat in one explosion which we find more heat, no excess carbon and carbon monoxide. We find we can burn coal with good results. I will continue this subject in the next issue and try to explain how to fire these old steamers and yet keep harmony with the public, after all I chose the heading of my articles, 'Let's Keep 'Em Puffing' and that's exactly what I intended to do. We cannot allow a beautiful, what can I call it 'Heritage?' to fall apart when so many people each and every year enjoy it. As I have tried to point out the power is unlimited and with the proper care we can make a good show and not too much smoke. Much success, if handled right, has been produced with some coke added to the coal. In many areas we may have to use some. If used in the right amount it will not hurt the grates.