The Miller and Milling Engineer by Charles E. Oliver
When the writer first conceived the ides of publishing this book he had most particularly in mind the benefiting of those millers who have to operate mills in isolated places. It is not possible for such millers to gain that knowledge and experience that their more favored brethren have who are living and working in localities supplied with mills of the most modern construction and with every known system, and where it is possible for operatives to converse with each other and compare notes, exchange ideas, and thus mutually assist each other. This work is based on the practical life experience of the writer, and states facts and not theories, and writes without bias to any system, machine or principle. His sole purpose has been to produce a work that would be helpful to his brother millers.
The milling business today requires the young man from the colleges more than it ever did in all milling history, for the reason that there has to be a higher type of intelligence than ever before to meet the great problems that confront the trade. In the past the millers have lacked education; they seemed to just drift into the mill as though there were few things to learn, and as a general rule they were men who thought more of a glass of liquor than of becoming more intelligent and the gaining of knowledge relating to their calling; and well I remember how my brother and I had to stand the jeers when we simply refused to be one of the crowd to visit the saloon. It was a struggle in those days to get the knowledge and high education in milling so necessary to become a head miller who really knew his business and be able to impart that knowledge to others,as the dead millers of that day were as a general rule a big headed class who were always afraid that their understudies were going to out do them and take their position away from them, which occasionally happened. For many years I have said and written a great deal in regard to the necessity of training the apprentice so that he will be fully capable of filling the place of the departing head men, and which is very essential indeed. In former days a boy entered the mill as an oiler or sweeper and gained the knowledge as best he could, and was not favored by any books on milling and very few milling journals, and so he had to get this knowledge of his calling by hard work and observation, for few head millers cared to impart any of their experience. The boy who is an observer, who asks questions, and is desirous of ascertaining the why and the wherefore of all things he comes in contact with is generally a boy that will make good if given half a chance, an answer that will put fear into the boy and cool his enthusiasm; but how wrong it is, for it might send the boy down and out, and lose to the trade one of great value. We as head millers oftentimes know the why and the way of doing things in a mill that it is hard to explain just why we do them to get certain results, and in such cases we are to be excused to a certain extent, but it has always been my desire to do all in my power for my understudy, because it is our duty to assist them if we are to get men to take our places. The boy who enters a mill today does not have to depend upon the old style of apprenticeship, and he can while working in the mill take a course in milling and baking that will fit him for any position with two or three years' training in the mill, for practical experience is absolutely necessary in making a really first class head miller. To the young man entering the milling business and to many of those who have been in the mill some years I would say, get right down to the business of getting all the knowledge about running a mill successfully that there is to be had; take all the milling journals possible to obtain; get the books on milling, for there is always something to be learned from them. Take a course in milling; work hard and conscientiously; never be a shirker, for there is no room in a mill for a lazy man, as there is always something needing your attention, for any moment something is apt to slip out of place, which is not to be wondered at with so many things to be depended upon in successful operation. Do not be satisfied with working in a small mill, but get into a mill of size in which there is a head miller of knowledge in charge, and get after all the ways in running a mill just as it ought to run to be a success. Learn to be neat and painstaking in all work; do not do anything in a slipshod manner, for it is just as easy to do a thing that will be approved of than to do it and be called down, which is the bounder duty of your superior to do. If you cannot have a clean mill then do not have one at all, for a filthy mill should not be allowed to run where the manufacture if human food is carried out. If you must chew, but I hope you do not, have a place to spit where it will not be noticeable by visitors; have every hole and corner just as clean as the open floor, for it is possible to have a mill that will be called a clean mill, and that is how I always tried to have mine. Get all the education you can, young man; and if you cannot gain it by the school method gain it by hard work and some course in correspondence school; work as hard as you know how, but intelligently, so as not to injure your eyesight or health, both of which are absolutely necessary to a successful career. I have a brother who had no education to speak of, yet today, is in full charge of the accounting for a large corporation haqving five large branch houses, and he did not enter the accounting field until he was over forty-five years of age, when he took his finishing course. Get the education; get chemical education as well if possible, as a chemist is necessary to the successful operation of a modern mill; work as hard as you know how; do not allow anything to escape you that is essential to your calling; and do not fail to gain all the mechanical knowledge possible, for it is all very useful in directing work that has from time to time to be carried out. Learn in life to have a place for everything and everything in its place; learn to clean out the corners and the center of the floor will take care of itself; seek after knowledge always and never rest on your past laurels and think you know it all; and, above all, never get self conceit and become a nuisance to yourself and everyone around you, as I have seen so many times in life. The happiness in a head miller comes to him by being a benefit to all boys who work under him, and nothing should give him more pleasure in the future than to see many of his former understudies in positions of responsibility. It you set your mind on being a head miller you can get to be one; and if you are going to be a head miller then put your whole soul into your profession and be one of the very best possible to be, and a blessing to that profession, and you will be that very thing.
Nothing is more revolting to a man or miller of refined sensibilities when going into a mill and finding it in undisturbed possession of oil, tobacco spit, cob webs, dust, dirt, bugs, and all the innumerable concomitants of the slovenly miller, and how a competent miller can work in such a place is beyond my comprehension. There is no place that gives greater delight to a real miller than that of a mill kept in that perfect order a mill should at all times be kept; and what is there that is prettier than a mill that is neatly painted; spouts varnished; shafting as bright as bells; machinery free from grease; floors free from oil; walls white washed; everything corner clear of dirt and dust; bugs an unknown quantity; and tobacco juice not in evidence? If a mill is kept spotlessly clean in every part it is seldom in possession of bugs or vermin, for they can, not thrive in a clean place as a general rule, yet how many mills you see with every corner piled like a pyramid with flour and meal, making them a breeding place for all manner of insects. It is difficult to be neat and orderly unless the instinct is there, but perhaps a few observations may serve to show the lax brothers where to begin. There is no place on the wall or floor of a mill for anything but what is absolutely necessary for the correct working of said mill; if the article is small, have a receptacle in a convenient place for it; if large, hang it up in a convenient and unseen place. When the mill floor and walls are free from unnecessary articles of every description, it is an easy matter to keep the mill looking speck and span at all times, and for the simple reason that dirt can not be hidden. The sweeping and cleaning of a mill seems very simple, but I assure your there are few who really know how to do it, and one thing is to be borne in mind: "Take care of the corners and the open spaces will take care of themselves." It is a fact that there are operatives in charge of mills today that could not hold the position of a sweeper in our large mills for the reason that they can not sweep clean. Machinery requires cleaning daily; the floors require cleaning whenever necessary. Do not leave empty bags, twine, meal or anything around, for they are liable to catch fire from spontaneous combustion. All the spare time of employees ought to be given to fighting dirt, cleaning and brightening all shafting, cleaning off grease from every part, and in this way the mill can be kept very clean. There are mills that i visit in which it is difficult to distinguish between wood and iron on account of the perfect way in which oil and dust have done their work, the bearings unrecognizable in many instances. A putty knife is one of the best instruments to clean the grease from floors and machinery, and it is handy because it may be carried in you pocket; and it is also handy in tightening up a screw when in a hurry. I have often been astonished how anyone could use the flour of some mills that I have seen in my travels, as they were littered from basement to roof with all manner of filth; and how any man, and especially a miller, can work in such a place is beyond my comprehension; but they were invariably loafing when they had an opportunity to shine up. A clean mill is a valuable asset in building up the trade of the mill and retaining that trade, and when it is kept spotlessly clean it is soon known far and near, and the products become known as being made on a spotless and sanitary mill. It is a good advertisement for any mill to have visiting day, when your towns people can be invited, and demonstrate to them just how the flour is manufactured, and you will be astonished how the women will talk about it to everyone they meet for days afterward. All people speak well of a clean mill, but a dirty mill is an eyesore to all people; so my advice to all is to have a clean mill or no mill at all. Every bearing in the mill ought to be kept free from dust and grease, for besides looking very unsightly it is always a source of danger and a fire hazard. To keep shafting as bright as a bell is an easy task when it is given the proper attention; but in cleaning it great care must be exercised or the loss of a life is the result. The best and safest method is to hang a heavy board against the downward side of the shaft while the mill is in operation, allowing the board to remain until the part is bright, then it can be moved whenever any of the operatives are passing, and in that way it will soon be bright, and once bright it is an easy matter to keep it so by wiping with waste. For keeping grease from the floors a triangular scraper is preferable, and can be made out of a reaper tooth or blade, with the handle fastened in the center and used the same as a hoe. When I was a grinder, bolter or purifier tender I was always cleaning the parts of my machine whenever I had a spare moment, as it was always a source of the greatest satisfaction to me to see everything around me speck and span, and I knew there are many millers that have time on their hand that they could use in the same work; yet their mills are as dirty almost as a hog pen. The outside of the mill and grounds can be kept clean and in good order; and there is no reason why trees can not be planted around a flour mill the same as a residence, as I have seen them; and they certainly add beauty and comfort to the surroundings, besides being inviting to customers, and enhancing the value of the property. Shafting when not bright will take hold of any flowing garment, and I have seen one death from that source, and knew of a girl having her scalp torn off by her hair lapping, and a woman having her clothes torn from her body, and it was lucky for that woman that she had a clear field to revolve around that shaft, for if there had been anything near that upright shaft she would have been mangled to pieces. The most economical and effective mill sweeping brush is the one of pure bristles, for they will always sweep clean, and especially where there are hardwood floors. Buy those that have the best bristles, for there are some that are only imitation brushes, and are soon worn out, and when they are partly worn they are beyond use. Do not use these brushes in wet or damp places, for they soon play out, and the brushes will bend over and stay that way, making them useless. Never stand bristle brushes on the head, for they soon become useless by being bent one way; and the only thing for these brushes is to hang them up on two nails placed about two inches apart for that purpose, when they will always be ready for use. The floor brushes are generally provided with two holes for the shank in order to be able to reverse the head and keep it straight. These brushes may be used both pushing and pulling with equal facility, and this keeps the brush in better shape, and it will wear longer. A floor can be swept with one of these brushes in about half the time it takes with a broom, and the floor is clean when it is swept, which gives much better satisfaction to the operator of the brush. With a hand brush of the best bristles the machinery can be kept very clean with little effort, and they are clean; but use one of the common kind and there will be disgust with all. After the machinery has been brushed, it is a good thing to rub them with a cloth, for this will give them a polish that will keep them equal to new machines. Keep windows clean so that daylight may enter in; remove cob webs, which removes a fire hazard; brighten all nickel and brass work; keep all bearings free from clotted grease, which is dangerous and a fire hazard in case of hot bearings; in fact, it is the best policy to keep a mill as spotless as it is possible.
Water is a mixture of one volume of oxygen gas with two volumes of hydrogen; proportion by weight being eight of the former to one of the latter. Water covers approximately 3/5 of the earth's surface, about 13/16 of the animal body, 7/8 of the plant life, and enters the mineral world also. Water boils at 100 degrees C. under normal pressure, and its freezing point is 0 degrees C. The greatest density of water is at four degrees C. and expands according to temperature. Water is almost incompressible; is a poor heat conductor; is the standard of specific gravity, and specific heat, and determining the unit of temperature, has great solvent power, and while water is neutral it will mix freely with some chemicals. For steam purposes the softest water possible is the most practicable. To determine the power of water, two factors are necessary, both of which are very important. The power of a stream varies directly as the head or fall, and the quantity of water. The head is considered the difference of level between the surface of water in the head and tail race. Take the measurement of the head while the water is flowing through the channels. Before building a mill which has to be driven by a certain stream, be sure that there is sufficient power necessary for the work required. It is best to have a reliable man to measure and ascertain the exact power of the water. After the actual power of the water is known, allow a loss of fifteen to twenty five per cent for friction, etc. For accuracy in measuring a stream of water a weir is necessary. Get the exact depth of the water about three feet above the weir. The most expeditious means of ascertaining the depth, and as nearly as any ordinary circumstances require it, is to take the depth every two feet, from side to side, and strike the average, which is near enough. Allow twenty five per cent off the actual horse power of the water. The fall may be ascertained by any kind of a level if the wheel is near the source of the head water, but if the wheel is at a distance an engineer or other reliable man ought to level the canal. Large streams can not be measured by weirs, and other means must be resorted to. If the stream is too deep to wade across, get a boat or raft, and take the depth in about half a dozen places, and strike the average. The course to pursue, and one of great importance, is to obtain the mean velocity of the water in the stream. Find a part of the stream where the water is moving very smoothly, and where the banks are even and nearly perpendicular. Mark off about three sections of 100 or 200 feet each, each section to be marked by placing a string across the stream. Take a submerged float - a long bottle sunk to the cork is good - and put it into the water at the highest mark, or a little above, so as to get up to speed before reaching the mark; note the exact time it occupies between each mark, and take the average. It is best to do this several times, putting the float in different parts of the stream. A man measuring a stream must use good judgment, and he will understand if he has obtained the approximate mean velocity. Take the number of soundings, add them, and divide the sum by the number of soundings, and the quotient is the mean depth of the stream. The mean velocity of a stream is eighty per cent of the surface velocity approximately. To ascertain the volume of water, multiply the mean depth by the width of the stream in feet, and the product by the mean velocity in feet per minute, and the quotient is the volume of water. To find the horse power of a stream, multiply the volume of water by 62 1/2 pounds, then multiply again by the head or fall in feet, which will give the foot pounds for stream; this product divided by 33,000 foot pounds will give the theoretical horse power. A cubic foot of fresh water weighs 62 1/2 pounds; a cubic foot of salt water 64 pounds. The useful effect of the turbine and overshot water wheels of the most modern type, and under the most favorable conditions, is about eighty per cent. A cubic foot of water is 1,728 cubic inches, or 7 1/2 gallons. To find the pressure on each square inch multiply the head in feet by 0.434, or divide by 2.30. Each 2.30 feet in height increases the pressure one pound. The measurement of water on overshoots. The overshot is propelled solely by force of gravity, but yet it would seem that it would gain certain per cent by impulse from the water upon entering the buckets. The water enters the buckets at the top or crown, which gives it its name "Overshot," distinguishing it from breast, pitch back, undershot, etc. The greatest field for the water wheel is on the development of small power where little water flows, and can be utilized for fall any height providing a wheel can be built to stand the requirements. The limit however to which it ought to go is 65 feet in diameter and width to allow it to use 2800 cubic feet of water per minute when built in single units. The claims for The I.X.L. water wheel carry the percentage of actual efficiency as high as 95%, which carries it much above that of the turbine, the highest of which is 92%, and to my idea and experience of the actual power of the water being used in their every day performance. The great advantage the overshot has over the turbine is that its efficiency at part gate is almost equal to that of full gate which cannot be said of that of the turbine. In a cut further on you will note the I.X.L. and its adaptability to driving mills by its facile transmission and increasing of the speed to conform with the speed of the line shaft. The cubic feet of water running on overshot, multiplied by the head in feet, "measured from the level of the water in the sluice to the level of the tail race," then by 62 1/2, and divided by 33,000 foot pounds, gives the theoretical horse power in the water. Eighty per cent approximately will be the actual horse power. Water will discharge more quickly from a conical aperture than from any other shaped orifice. Doubling the diameter of a pipe increases its capacity four fold. Two hundred and thirty one cubic inches of water weighs eight and one third pounds, and measures one gallon. Approximately, the loss of head in one hundred feet of pipe is equal to .52 the velocity squared, divided by the diameter of the pipe in inches. To find the horse power at 80 per cent efficiency, when head and volume are known, multiply the head by the cubic feet, and the product by 0.00150. The area of a circle equals one quarter of the diameter, multiplied by the circumference. The diameter of a circle, multiplied by 3.1416, gives the circumference. Divide the circumference by 3.1416, or 3 1/7, and you have the diameter. To find the velocity in feet per minute necessary to discharge a given volume of water in a given time, multiply the number of cubic feet of water by 144, and divide the product by the area of the pipe in inches. A turbine is less affected by back water than a water wheel. If there is an abundance of water put in a turbine, as it gives the desired speed at once, doing away with all the cumbersome and heavy gear necessary for a water wheel. The gate of a turbine is generally in one solid piece, is circular in form, and opens all the ports at once, letting in the water in equal quantity at each port. The turbine takes in the water all around. In some patterns it discharges at the center, and in others underneath and above. Those discharging below are preferable, as it requires energy to discharge above. A turbine works solely by pressure and reaction so that the more nearly the water approaching it being dead, the greater is its efficiency. The reason why a turbine discharge must work in dead water is that the air being expelled, the falling water causes a pull, or vacuum; thereby giving the wheel a larger percentage of useful effect, and under this action the suction pipe works. Some engineers claim that they can get about equal power from a turbine using twenty feet of suction pipe, as can be obtained from one placed at the foot of the fall. Be sure to put the wheel at the foot of the fall in order to economize power and save annoyance, for it does not appear reasonable that the same amount of power can be obtained by the suction tube. Be careful to have the shaft from the turbine, bevel gears, and line shaft put up in such a way that little or no vibration may be felt, thereby saving both trouble and expense. Many different methods may be applied to falling water in the working of machinery. The action of water rotates shafting in three different ways; by impulse, weight and reaction. Water wheels work mainly by the weigh of the water and at low velocity, while turbine works mostly by impulse and reaction, and at high velocity. Water wheels are generally used in three forms, namely: The overshot, the breast, and the undershot, the former being the most efficient considering the amount of water used. For this reason, the overshot wheel is always preferable when the supply of water is limited. When wheels are simple in construction, erected in a substantial manner, with buckets of the most economical form, their efficiency is almost as high as that of a turbine. The water wheel is not as good as the turbine in very cold climates on account of ice troubles. Water wheels work by the weight of the water, and care should be taken to allow only enough water to go onto the wheel to fill the buckets, as more than that is superfluous and therefore wasted. The overshot has a little advantage inefficiency over the high breast wheel, on account of the water striking the wheel in the direction it is running, but the amount of power developed in this manner is very small. A water wheel should always run clear of the water in the tail race, as it is more easily affected by back water than the turbine. When the mill is standing for a day or so, it is good policy to look the wheel over to see that everything is in order, and to make repairs on the buckets if necessary. When water is scarce, a wheel should run without splashing or wasting any water, as every drop counts in dry weather. Never waste a moment in studying up plans to use the water after it has passed the wheel, as its power is spent until it meets another fall. Water wheels are designated as overshot, undershot, high breast, low breast, middle breast, pitch back, etc., according to just where the water enters the buckets. The following information presented was courtesy of the Fitz Water Wheel Company of Hanover, Pennsylvania. The Fitz Water Wheel Company claim of 33% more power is given off per water used than any turbine made can give. A claim of 90% efficiency is made for the I-X-L wheel. The I-X-L for all purposes is very hard to beat. By repeated test the I-X-L has shown that it will develop at least 33 1/3 % more power than the best turbine builders made using the same amount of water. We are well aware that the best turbine builders claim from 80% to 85% efficiency for their wheels and pretend that this is proven by their records in the testing flume. Such claims are absurd. It is true that a few turbines have given a little over 80% efficiency in the laboratory when tested at full gate, but it must be remembered that these were large wheels built regardless of expense and working under the most favorable conditions known. Even in the case of the large turbines, the practical value of these tests may be seen from the fact that no two wheels of the same size and same make, would give the same efficiency, and often the same wheel, when tested at different times, would very considerably. Small turbines, such as our wheel competes with, have never shown good results even in a laboratory test. Back water, which will soon stop a wood overshot, has very much less effect on the I-X-L. We always calculate out wheels to accommodate from one fourth to one half more water than the normal volume of the streams which drive them. Consequently at flood periods more water can be used on the wheel, thus overcoming the loss of head in back water. Owing to the unique design of our buckets there is little loss of power by friction or sucking up water when wading. A careful consideration of the above fact must lead to the conclusion that the I-X-L Steel Overshoot is not only the best water wheel on the market but also the cheapest, for it gives much the best value for the money expended. The I-X-L utilizes every bit of water to its fullest possible extent. The value of the increased power alone, that it yields, may be worth more every year than the whole cost of the water wheel, to say nothing of its greater durability and more satisfactory service. The I-X-L Steel Overshoot Water Wheel is built entirely of iron and steel. Its high efficiency is due to its correct principles of design and the high class workmanship and material used in its construction. The word "Overshoot" is simply an arbitrary spelling which we adopted some time ago to distinguish our wheel from the ordinary "overshot" water wheel. For the sake of brevity, our wheel is frequently referred to, merely as "The I-X-L" or often as "The Fitz Wheel." We do not wish to convey the impression that the I-X-L is the best wheel for all locations or for all conditions. Our field is in the development and improvement of small water powers. By small water powers we mean those having falls of less than sixty feet and volumes of water smaller than 3,000cubic feet per minute for single units of wheels. Even within those limits, there are certain conditions to be met with occasionally which call for other types of wheels. Within its field, however, there is no other type of water wheel in the world that can compete with the I-X-L. Put your conditions up to our engineers and let us tell your what we can do for you. We will guarantee in every case to greatly improve your power or to let it alone. The size of an I-X-L depends largely upon the situation, but we usually make the diameter about two feet less than the amount of the available head. The force of the water above our wheel is not lost but act by its impulse upon the wheel just as it acts on a turbine or impulse wheel. In other types of overshot wheels this force is almost entirely wasted but the shape of our buckets and our method of applying the water to the wheel enable us to utilize this impulse. The I-X-L will develop from 90% to 95% efficiency depending upon the diameter of the wheel; or at least one third more power than any other wheel using the same amount of water. It will develop just as high efficiency at one third or one fourth capacity as it will when at normal capacity. A turbine will do practically no work at all when run much below full gate, so that in the course of a year's run on a variable stream, the I-X-L will develop twice the power of the most economical turbines. As an auxiliary power the I-X-L Steel Overshoot has ho rival. This wheel is helping out a 400 Horse power engine. It runs constantly, twenty four hours a day, using the natural flow of the stream and assisting the engine at all times to the full extent of the water power. No matter how low the creek gets, it is always capable of saving a good deal of coal when used in this way. The I-X-L adapts its speed perfectly to that of the engine. It cannot hold back as a turbine would do when water gets scarce. An I-X-L will synchronize just as well with a gasoline engine or motor as it will with a steam engine. A turbine is worse than useless in a place like this, for most of the time the engine would have to be pulling the wheel along in addition t driving the plant. The rim has teeth or gear wheel which imparts its force to a pinion of smaller diameter, and which gets the speed necessary instead of resorting to cumbersome bevel gearing. You will note that the buckets are curved in such a manner with the entering of the water until about two feet from tail race level, getting all the useful effect possible. There is no doubt but what this type of wheel is one of the most economical and practical of water wheels to date. This wheel allows for almost any head according to the construction, and works by weight of the water only. The low velocity of water wheels is one cause of the loss of useful effect, and the imparting of the power to mills at low speed is another cause why I prefer the turbine when there are other conditions to balance, such as high head, back water, etc.
The turbine acts principally by impulse and reaction, and centrifugal force has something to do with its efficiency. The reaction of the turbine is caused by the spouting or discharge velocity of the water, which should flow or spout in the opposite direction to the rotation of the turbine. No better or more reliable power can be found for a mill than the turbine where there is enough water at all times, so that it may be run at full gate if necessary. The power is always in the control of the miller, and if everything in connection with the gates is properly arranged, it is regular and effective. In this department of the mill as in every other, too great economy should not be exercised. The flume and penstock must not be too small; as to cause the water to run and fall at the rate of 300, when it should fall at the rate of about sixty feet per minute. Speed means friction, and friction means loss of pressure, and therefore loss of useful effect. When construction a penstock for a wheel, always be careful in laying the bed or foundation, so as to have a good discharge pit. If of a soft substance, such as sand, clay, earth, or any loose material, mud sill will have to be put it, with sheathing of two inch plank on the bottom. There is no need to be afraid of having the discharge pit too large. It should be from four to eight feet deep, four to eight feet wide, or larger according to size of wheel, and should extend out several feet from the penstock, sloping upwards until it touches the level of the tail race. The free discharge of a turbine is very important, and unless the water passes away from the wheel freely it will react, thereby lowering the percentage of useful effect. Have the turbine discharging into dead water at all times, and prevent air entering the turbine discharge, or the vacuum will be lost. When erecting a flume and penstock it is well to calculate the timbers very carefully, for the pressure is very great, and the expansion and contraction of the timbers by moisture is also very great, and must be guarded against. This method of erecting a flume that will give very good service, is very simple, and when built on the right lines is very durable. Large penstocks should rest on side walls or pillars, and pillars are preferable, as they allow free discharge of the water from the turbine. Frame the floor of a penstock very strongly; cover the floor with 2 inch to 2 1/2 inch soft planking, tongued and grooved, allowing space for the discharge tube of the turbine to pass through, and a perfectly level place for the flange of the wheel to rest. The turbine tube hole must be large enough to move the wheel slightly to center it correctly. Right under the turbine, should it be large and heavy, there ought be be placed 4 6" X 6" uprights to support the center of the floor, or it will sag with the great weight resting thereon. After planing the floor where the flange rests, put tar, with three or four layers of soft twine, which will prevent the passage of water as long as the penstock stands. Sound judgment teaches that for heads of twenty feet or over it is the most economical plan to put in an iron case and penstock. In some localities lumber and labor are very cheap, and iron is very expensive, so that wooden penstocks have to be made for high heads. After the water had been in it for a few hours it stopped leaking, and has since cost little or nothing for repairs, after dome continual service. The straight penstock has many advocates, but in the opinion of the writer the armed one is preferable, as the bearings are on the outside, and it looks much neater than the straight one. Some claim that there is more power on the turbine by a straight shaft, but they do not take into consideration that the pressure is equal on all parts at the bottom of a penstock. Of course, there would be a difference in favor of a straight penstock if the water was making a mad rush of about 300 feet per minute to get to the wheel, thereby losing a part of its useful effect at the farther side of the turbine when in an armed penstock. Never be opposed to having an arm in the penstock, for it is large enough to allow water to sink easily, the loss will be so small that it will be overcome by the bearing being out side, away from sand and grit. They will also last much longer when they are free to be lubricated. These remarks are all for the setting if vertical wheels. It is so seldom that horizontal wheels are used that all the necessary instructions may be obtained from the makers. There are two classes of turbines, the impulse and the pressure or reaction, and there are those that have inward, outward, parallel and axial discharge. The turbine is capable of developing tremendous loads under very high falls and pressure, and where it would not be possible to use water wheels, and can be used of any amount connected to one shaft by the horizontal type. Mr. Joseph P. Frizell claims as high as 92 per cent of efficiency has been obtained by the Boyden wheel, and 88 percent of the actual power of the water, which is remarkable if the tests made were absolutely accurate, and were made by those not having an interest in the wheel. When setting a vertical wheel, place it at equal distances from the side of the penstock, so as to allow the water free entrance; often for high falls, and where it is difficult to build a pensock, a draft tube is used, placing the wheel twenty or thirty feet above the tailrace. It is best never to allow more than twenty feet of draft tube; set the wheel on the bottom, if possible, as the draft tube is troublesome, and must be kept perfectly air tight, or its efficiency is impaired. When a draft tube is restored to, let it be conical, the smaller end at the turbine. The bottom must be in dead water at all times. Always make the deck of a penstock as strong as the shaft. A few bolts at intervals is good economy. In placing large wheels, the draft tube being separate, it is best to place it in position first. Keep the water running to the wheel as free from debris as possible. Put a rack in the fore bay, and if one will not do put in two, for they must not be too fine. Where the feeding canal runs for miles, and is open, it receives all manner of refuse. In this case it is wise to have three racks; the first with bars about six inches apart, the second three inches apart, and the third three quarters of an inch apart for small wheels. The bars should be one inch apart for wheel up to forty inches, and one and a half to two inches apart, for large wheels. Be careful to have the head and tail race large enough to allow the water perfect freedom to enter and discharge. It is an easy matter to arrange an automatic rack cleaner, which can be driven by a crude paddle wheel. All that is required is a traveling comb, running at an angle, to drop the debris after reaching the top of the rack. It may also be driven by the mill, when convenient. A good rack can be made of iron or steel bars, half an inch by two inches. Drop them into a half inch broad, tapered up stream. Leave the bars clear at the top, so as not to impede the rake. Incline the rack to an angle of about forty degrees. Avoid turns in the fore bay whenever possible, especially sharp ones, as it impedes the flow of water to the wheel. Three feet per second is the speed generally allowed for water to travel to the wheel, but it is better to allow it a speed of one to one and a half feet per second. When considering the building a mill on a stream, the first is to ascertain the head and fall, and the amount of water passing, and it is the best of policy to engage an engineer for this purpose.
In the last few years wind power has receded into the background so far as its use in driving flour mills is concerned; though there are a few complete roller mills driven by wind. Wind, what a word, and what an instrument of destruction it can become when let loose in all its fury. Wind is caused by atmospheric changes and pressure, being forced from high barometric to low pressure. Wind is generally more forceful up from the earth on account of there being nothing to retard its flight, and no friction on the earth to impede it. The introduction of windmills into Europe was about the year 850 A. D., and no doubt used very extensively in those days. The principle of the action of the windmills is very similar to the action of the turbine, the wind acting upon the sweeps revolving from a shaft at an angle with the direction of the wind. The rotating plan of the sails is at almost right angles to that of the wind, being that the wind very there had been provided a regulator to keep the sails facing the wind. The post mill of the German type of windmill had the whole body of the mill revolve in keeping the sails to the wind, many having a staying post always behind to support it against the force of the wind. The Dutch windmill had only the head to revolve, the lower part of the building being built of brick, stone, or timber as desired. The rotation of the tower was done by hand in the former days, and the rotating was accomplished by a gear wheel and a circular rack, placed outside the upper tower. The latest type of mills was arranged with a second or small set of sails that provided auxiliary and automatic power which revolved the tower. These sails were the invention of Andrew Meikle, and were called the Fan Tail, and are arranged directly opposite to those of the driving sails, and rotate at almost right angles to them. The windmill is generally placed on high ground away from all obstruction possible in order to get the greatest advantage of the forces necessary to their success. When a boy it was always a great pleasure for me to go with my father to get feed from a very fine specimen of windmill run by a very big hearted miller named Paul Bastow, hart, England, and I as a boy have stood in awe and wonder at the tremendous sweep of those great sails as they rotated at a speed which seemed that they meant business, and woe to the man that stopped too near them, for it would be instant death. The main sails shaft is at an angle of about 10 degrees in order that the sails may clear the building, and receive the full impulse of the breeze. The width of the sails widen from the shaft to their extremity, and have a sweep of about 50 feet or more in some of the higher towered mills. The sails are provided with a sort of shutter, many of them that can be opened and closed according to the velocity of the wind, and when made of canvass can be reefed. The large mills have generally carried 4 to 6 sails, but of later years there has been great improvement in the windmills, and today they are made like a turbine with as many sails as the can conveniently carry, and are used for almost every purpose on American farms, etc. The sail shaft of the large windmills is centered in the center of the tower, and connects with a vertical shaft in the mill by gears. The windmills for pumping is one of the best and cheapest powers there is providing it is given the attention that all machinery must have in order it can function correctly, but to neglect them means ruin and waste. The pumping windmill and tower is made of iron or steel, and with proper care they ought to last for years, and especially when fitted with ball bearings. There is no reason why mills cannot be built today for grinding feed, cereals, and small capacity flour mills and be driven by wind power with gasoline as auxiliary power, for what is there that is cheaper than the wind, and having the mill on high ground it would get a good deal of wind power.
The day of usefulness of the burr in a flouring mill has almost passed away. The man who upholds them against rolls is generally considered a little unbalanced mentally, or out of date. That their work is inferior to that of rolls is not to be doubted, and there is but one place where they are of use in a roller process mill, and that is on pure fine middlings, and there they can do much good work when properly handled. A burr must be placed upon as solid a foundation as possible, or severe vibration will ensure. After a burr is dressed and ready to be laid level the stationary or bed stone, placing the ends of the lever over each leveling screw, which are placed triangularly beneath the burr, and when thoroughly level proceed to tram, to fine out if your spindle is perfectly plumb, which is very important. Various forms of tramming sticks and pots are in use, those most commonly employed being of wood and fastened on the head of the spindle. After the tram is in position, feather fixed and ready, turn the spindle gently, and take notice that it touches all around the skirt of the stone. The adjusting screws are in the foot step of the spindle, and if the feather touches on the north side of the burr loosen up the north set screw very little, and tighten the south one, and so on with any others. When the burr is laid, and swinging on the cock head, the faces being about a quarter of an inch clear of each other, walk around it and press it down with a quick motion. The place that is up is light in balance, and requires weighting at that particular box, or the place that is down may be lightened until the stone is equal at all parts, which condition is called the standing balance. Now as to the running balance. In large mills of former days the spindle of each burr had a small pulley to run it until a running balance could be obtained. By some means, or by its own drive, put the burr in motion, free of outer fittings, such as curb or hopper; lower it until it nearly touches; get a piece of cardboard or a thin piece of lath; put on a thin coating of raddle, or any liquid that will mark the running burr, and push it between the stones, taking care to let it rest on the still one, and the coloring being on the upper side will mark the light side of the running burr; as the balance is just the contrary to the standing balance. Adjusting weights are generally placed on the back of the runner, for raising or lowering as the case requires. If a foot step heats, lift out the spindle and clean it out well. If it still gives trouble put in a large copper coin and oil with the best oil. Every iron about a burr requires marking that they may always be replaced where they belong. Burrs have various dresses, namely: 13 threes, 9 fours, 22 twos, 8 sevens, and many others, referring to the quarter or divisions. A burr, with the work put in to run with the sun when in the northern hemisphere, is the most convenient to dress, as the dresser may lie on his left side when at work. Have the bush just tight enough to allow for expansion of the spindle, and well greased, being careful not to put the spindle out of tram by doing it. It should be adjusted before tramming. Burrs having two or three furrows to the division do the best, coolest, and most work. All the furrows should be run through to each end, as this keeps it cooler. Always have the face of a burr tapering from a circle five inches from the rim to the eye, that is, for the runner only, and say one quarter inch lower at the eye. It will then act as a gradual reducer instead of mashing at the first stroke. A burr in this condition will have greater capacity, be cooler, take less power, and its product will be of a better quality. Keep the furrows sharp, but smooth, to insure good work, and put in about six cracks per inch for corn, eighteen per in for wheat, and about twenty four per inch for middlings. Furrows should be curved at the cutting, or feather edge, as they keep sharp longer, and do much better work. The furrows should be wider at the eye than at the skirt, which causes it to crack more gently upon the grain entering, and also gathers better. Give the furrows draught in inches equal to the diameter of the burr in feet. When taking up a burr, see that it does not strike the driver too hard, or it may cause trouble in the adjustments. When the burrs are apart, and laid out, clean the faces of each until there is not a speck of dust on the surface, or it will stick to the staff. It is a good plan to beat the face of each with a piece of three or four inch belting, which will remove the dust from the pores, then sweep well. Take the staff out of its box, wipe, and lay the raddle, or coloring material equal on all parts. Then brush it lightly with the ends of the bristles of a soft brush until the face is just moist, take it in both hands; placing the tips of the fingers in the groove on the staff for that purpose; stand on the center of the burr with feet clean, and with a swing from one side make it circle over the face of the burr. Be careful not to let the staff stand long, and when in motion, see that each end projects an equal distance over the skirt. The face, inside of five inches of the skirt must be chipped off as long as the color show on it. When through with the staff, wipe the working face until perfectly dry, and put it away. Always handle it with the greatest care, as the burr depends upon the staff for its good results. Staffs are generally made of the finest, close grained hard wood. A staff should be proved once a week when in use every day. A staff proof and spirit level are combined in one instrument. When proving a staff, rub a very light coating of fine, thin oil on the proof, lay the working face of the staff on the oiled surface and move it. The parts touched with oil require scraping off with a piece of sheet steel, kept sharp at the edge for this purpose. The furrows on the burr are best when made one eighth of an inch deep for middlings; about one fourth of an inch for wheat, and small grain; and about five sixteenths of an inch for corn. The self adjusting driver if today makes it much easier to keep a stone in running balance than when the old solid driver was in use. Never run a burr without a sweep, which is a small piece of steel fastened on the ring of the runner to carry the stock around to the discharge spout. Never get a burr so low as to make the stock clammy or hot that it will burn the fingers, which is a frequent occurrence. This will ruin the stock; and fill up the furrows, making it necessary to take up the stone, to clean; often having to wash same. There is no denying the fact that a burr will do splendid work on pure middlings. But the trouble is in dressing, getting empty, securing a competent man to dress it, allowing it to run until every furrow is obliterated, and other inconveniences. It is very dangerous to run a burr at a high rate of speed unless the binding hoops are thick, well made, and of sufficient strength to withstand the tremendous centrifugal strain. Bear in mind that a burr is only in so many pieces, and when running every piece is ready to fly according to the force attracting it, and woe to the person standing besides the millstone when it bursts. When it is remembered that centrifugal force is anything running or extending from the center, a good illustration of this force may be obtained in a simple manner. Take a stone weighting one pound, fasten it to a string, and take the end of the string and swing it round and round. The force thus develops will give an idea of the strain on burrs, fly wheels circular saws, and all heavy circular bodies. Keep the back of the runner smooth, and in good condition, which is easily accomplished by the use of plaster Paris. There will always be a place for millstones in mills and factories making paints, spices, cement, mineral products, etc., that are in daily use and consumption. Burrs are in constant use in feed milling, and many there are who ask for burr flour, saying that the roller flour is not the equal to the good old stone ground flour. Many country mills have built up a very flourishing business on burr ground corn meal, buckwheat flour, graham flour, etc. Many mills are making money by advertising water ground corn meal and buckwheat flour; just as if the power had anything to do with the making of the meal, but then, the people have to be humbugged. The main drawback to stone milling is the correct dressing of the burr, and so few millers of today understand it, that it is difficult to even get them dressed at any price. The power required in burr mills to make a barrel of flour, approximately, is ten horse power, or three and a half barrels may be made on twenty four hours by each horse power. No definite test that can be relied upon can be made of other machinery in flour mills,as the variation in feed in different mill renders it impossible to make such a calculation. The ten horse power per barrel of flour per hour, in a well regulated mill includes everything, wheat cleaning, receiving, etc. However, there are mills in which it will take as high as sixteen horse power per barrel per hour, as it takes fully one half of the power to run the complicated and unnecessary machinery. The man in charge may be using several horse power in mashing and pulverizing his stock on the rolls, which is unnecessary. Some mills have more returns in the flow that straight runs, which absorbs much power uselessly. A man must be constantly on the lookout around his mill to save all the power that he can, as it is a very important factor in the item of profit at the close of the year's business. Every little thing that will absorb unnecessary power should be carefully watched. Let a bearing be ever so small, if it is without oil it will increase the amount of fuel used. A four foot burr, running at 150 revolutions per minute, and grinding six to eight bushels per hour, requires seven and a half horse power. My father Uriah Oliver, who claimed until his death that we would return to stone milling, but I was forced many times to ask him to try and forget such an idea. I may say that the author had four years steady work on the burr as second, then first stone dresser, and did nothing else, and it was pleasant work, as we took the burr up almost in the condition it was put down, and the work was very easy. There are millstones of various manufactures and kinds of stone used, namely, French, peak, gray, esopus, sandstone, etc. There are the vertical, under runner, upper runner type of burrs, all of which are good for any work they have to do when set up and dressed correctly, and when in perfect face and tram, and with sharp furrows they can turn out the work very fast.
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