Boiler maker

“ The hand tools needed by boiler makers are equally few, consisting of riveting hammers and hammers for striking the chisels, tongs to handle hot rivets, chipping chisels used in trimming the edges of plates, cape chisels for cutting off iron or making holes in the sheets, expanders to set the tubes, and also drift pins to bring the punched sheet exactly in line. ”

“ Incrustations on the heating surface not only lessen the efficiency of the boiler by obstructing the transmission of heat through the plates and tubes, but if excessive they become a source of considerable danger by permitting the plates to become overheated and thereby weakened. When the feed-water is very impure, therefore, the boilers used are those which permit of very easy cleaning, such as the Lancashire, Galloway and Cornish types, to the exclusion of multitubular or water-tube boilers in which thorough cleaning is more difficult. ”

“ It is sometimes found that the operating force is not fully acquainted with the boilers and apparatus. Probably the most general of such shortcomings is the fixed idea in the heads of the operatives that boilers run above their rated capacity are operating under a state of strain and that by operating at less than their rated capacity the most economical service is assured, whereas, by determining what a boiler will do, it may be found that the most economical rating under the conditions of the plant will be considerably in excess of the builder’s rating. ”

“ The din of the frame shed and the unearthly noise of the pneumatic apparatus on the headstocks and plates is not to be compared with the tremendous uproar of the boiler shop. Here are no less than two hundred huge boilers, either new ones being made, or old ones undergoing repairs and engaging the attentions of four or five hundred boilersmiths, to say nothing of tubers and labourers hammering and battering away on the shells and interiors. There are boilers in every stage of construction and in every conceivable position on the stocks. ”

“ Where capacity in the sense of overload is desired, the type of boiler selected will play a large part in the successful operation through such periods. A boiler must be selected with which there is possible a furnace arrangement that will give flexibility without undue loss in efficiency over the range of capacity desired. The heating surface must be so arranged that it will be possible to install in a practical manner, sufficient grate surface at or below the maximum combustion rate to develop the amount of power required. ”

“ This form of boiler is frequently used to good advantage where it is desired to utilize ground space, and where there is sufficient head room. Properly constructed, it is economical as a steam generator.
From the foregoing it will be seen that the structural features of all boilers are so arranged as to provide for the exposure of the largest possible area of water to a heated surface so that the greatest amount of heat from the fuel may be absorbed. ”

“ Economizers find their largest field where the design of the boiler is such that the maximum possible amount of heat is not extracted from the gases of combustion. The more wasteful the boiler, the greater the saving effected by the use of the economizer, and it is sometimes possible to raise the temperature of the feed water to that of high pressure steam by the installation of such an apparatus, the saving amounting in some cases to as much as 20 per cent. ”

“ The boiler and plating shops have been affected by the general tendency to specialize manufactures. Firms have fallen into the practice of restricting their range of product, with increase in volume. The time has gone past when a single shop could turn out several classes of boilers, and undertake any bridge and girder work as well. One reason is to be found in the diminution of hand work and the growth of the machine tool. Almost every distinct operation on every section of a boiler or bridge may now be accomplished by one of several highly specialized machines. ”

“ The boilers are upright cylinders, about 5 feet in diameter and 16 feet high, with semi-spherical ends, provided inside with straight perforated diaphragms, between which the chips from one cord of wood are confined. A solution of caustic soda, at 12° B., is introduced with the chips, and fires are started in a furnace underneath. At other works the boilers are heated by steam circulating through a jacket which covers the bottom and sides of the boiler. ”

“ Amongst the essentials are a receptacle capable of containing the water and the steam produced by its evaporation, and strong enough continuously to withstand with safety the highest pressure of steam for which the boiler is intended. Another essential is a furnace for burning the fuel, and a further one is the provision of a sufficiency of heating surface for the transmission of the heat produced by the combustion of the fuel to the water which is required to be evaporated. ”

“ The tie rods should be set up snug and then slacked slightly until the setting has become thoroughly warm after the first firing. The boiler should be examined internally before starting to insure the absence of dirt, any foreign material such as waste, and tools. Oil and paint are sometimes found in the interior of a new boiler and where such is the case, a quantity of soda ash should be placed within it, the boiler filled with water to its normal level and a slow fire started. ”

“ In order to burn the finer grades of anthracite coal in sufficient quantities to obtain boiler rating with the hand-fired grates, and in order to secure a large excess over boiler rating with other coals, a system of blowers and air ducts has been provided in the basement under the boilers. One blower is selected for every three boilers, with arrangements for supplying all six boilers from one blower. ”

“ From the boiler manufacturer’s standpoint, the only way of establishing an efficiency that has any value when guarantees are to be met, is to require the grate or stoker manufacturer to make certain guarantees as to minimum CO2, maximum CO, and that the amount of combustible in the ash and blown away with the flue gases does not exceed a certain percentage. With such a guarantee, the efficiency should be based on the combined furnace and boiler. ”

“ Notwithstanding all the attempts that have been made, the use of a lead-lined boiler is a serious objection, and any process which will fulfil the conditions on which the bi-sulphite processes depend, and which at the same time admits of the use of the ordinary iron boilers, is an obvious desideratum. ”

“ But in modern boiler shops little hand work is ever done; instead, plates 4 ft., 6 ft., or 8 ft. in diameter, and fire-box plates for locomotive boilers, have their entire flanges bent at a single squeeze between massive dies in a hydraulic press. In the case of the ends of marine boilers which are too large for such treatment, a special form of press bends the edges over in successive heats. The flanges of Adamson seams are rolled over in a special machine. A length of flue is rotated on a table, while the flange is turned over within a minute between revolving rollers. ”

“ The steam pressure of the repaired boiler is usually fixed at about a hundred and twenty-five pounds per square inch. The capacity of each boiler is very great, and the composite power of the whole set formidable; if one of them should happen to explode the result would indeed be disastrous. A small staff of men superintends them by day and night, and greater care is taken of them than was the case formerly. I can remember when the shed was several times within a hair’s breadth of being blown up and forty or fifty men hurled to perdition. ”

“ The crossing of the seams, as in Fig. 25, page 21, adds much to the strength, and also often prevents a rent from continuing forward to a dangerous extent.
Fig. 52.
It is scarcely requisite to mention the necessity of good material and workmanship to secure strength in a boiler, however perfect the design. If the plates are of weak and brittle iron, or imperfectly manufactured, they will never make a good boiler. Apart from the strain upon the boiler when at work, the iron has to undergo the strain of the necessary manipulation, shaping, and punching, during the construction of the boiler. ”

“ In the upright type of boiler the boiler cylinder is placed on end, the fire is built at the lower end, which is a firebox surrounded by a water jacket, and the smoke and gases of combustion rise straight up through vertical fire flues. The amount of water carried is relatively small, and the steam space is also small, while the heating surface is relatively large if the boiler is sufficiently tall. You can get up steam in this type of boiler quicker than in any other, and in case of the stationary engine, the space occupied is a minimum. ”

“ A pipe C is used for heating the liquor by means of waste steam at the commencement of the operation. The grass is fed into the boiler at the opening D. At E E are gauges for showing the height of the liquor in the boiler, F F F are pipes for the supply of steam, strong ley, and water, and the door G is for the discharge of the boiled grass. Each boiler is capable of holding 3 tons of esparto, and the boiling is completed in about two and a half hours, at [46] a pressure of from 35 to 40 lbs. per square inch. It is said that the boiler effects a saving both in time and the amount of soda used. ”

“ It is especially adapted for power-plant work where it is necessary to use a boiler in which steam can be raised quickly and the boiler placed on the line either from a cold state or from a banked fire in the shortest possible time, and with which the capacity, with clean feed water, will be largely limited by the amount of coal that can be burned in the furnace. ”

“ A modern, highly efficient and economical steam driven high speed compressor plant must be installed so as to get the maximum power out of coal. The boiler room will contain two 250-H. P. water-tube boilers with automatic stokers and coal bin overhead holding two weeks' supply of coal. Steam pressure 175 lbs. As the firing of the boilers is automatic and requires practically no work on the part of the engineers, no firemen are needed. ”

“ It is automatically taken care of where the house is heated by an oil burning system. With a coal burning steam or hot water plant, there is now a cylinder that can be attached to the boiler below the water level. In it there is a coil of copper pipe through which circulates the domestic hot water supply. This works admirably. There is always a sufficient supply but it is never so overheated as to scald the heedless person who plunges a hand under a boiling stream of water. ”

“ In the working day not a moment is wasted. When the whistle blows the full working pressure is ready to begin work and maintain duty until night. There is no fluctuation of pressure due to careless boiler attendance; no wheeling coal or water barrels to keep pace with advancing channelers. Some of the old boilers, discarded from steam service, are used as air receivers, these and other reservoirs, together with the pipe line itself, unite their immense storage capacity so that throughout the day there is no peak load. ”

“ When steam is being raised, the super heater is flooded with water, which is drained out through a blow-off pipe before communication is opened with the steam-pipe. In large boilers of this type, two steam-chests are placed side by side connected together by two cross steam pipes and by the mud drum. Each, however, has its own separate feed supply. The largest boiler made has two steam chests 41/2 ft. diameter by 251/2 ft. long a grate surface of 85 sq. ft., and a total heating surface of 6182 sq. ”

“ Always purchase a boiler with sufficient capacity to allow a small margin beyond its ordinary requirements. Be sure and have the boiler or boilers properly set so that the best results may be derived from the fuel burned. Many good boilers are condemned because they do not steam well on account of bad setting.
If a locomotive style of boiler, see that it has a large fire box (well stayed) and a sufficient number of flues to allow of easy firing and good combustion of the fuel without being obliged to use a forced draft. ”

“ The study of the theory of combustion, draft, etc., as already given, will indicate that the question of efficiency is largely a matter of proper relation between fuel, furnace and generator. While the possibility of a substantial saving through added efficiency cannot be overlooked, the boiler design of the future must, even more than in the past, be considered particularly from the aspect of reliability and simplicity. A flexibility of operation is necessary as a guarantee of continuity of service. ”

“ It must be remembered that dry steam, as it is used through the engine or for other purposes, carries away none of the impurities which pass with the water into the boiler; hence, in a battery of boilers burning, say, 20 tons of coal per day and evaporating 10 lbs. of water to a pound of coal, there is a body of water going through them every day of 200 tons. Multiply this by 300 days for a year = 60,000 tons, and it will be seen how very great is the problem of keeping the interior of the boilers free from scale and deposit. ”

“ The Hot-water System is so generally adopted that there are as many plans of apparatus provided for it as there are days in the year, and, as a matter of course, everybody’s boiler is the best. To a beginner in hothouse practice the variety of boilers must be extremely perplexing, but it will soon be found that they differ but little in essential particulars. In every case there is a furnace beneath a boiler or in the centre of it, and from the boiler proceed iron pipes, laid horizontally around and about the house. ”