Blower

“ There is an electric-heating device in the stand and a blower which forces the air through ducts into the box on top, where the hands are held while drying. A lever, operated by the foot, turns the current of hot air into it and sets the blower at work. ”

“ Every solid-fuel boiler should have a steam-blower in the chimney for drawing up the fire; and if a really fierce blaze is aimed at, the exhaust from the engine should be utilized for the same purpose. ”

“ Blowing appliances, among which are included bellows, rotary fans, blowing engines, rotary blowers and steam-jet blowers, are now also employed for forcing pure air into buildings and mines for purposes of ventilation, for withdrawing vitiated air for the same reason, and for supplying the air or other gas which is required in some chemical processes. ”

“ Besides the use of compressed air supplied in the way just indicated, several other devices are in use to aid the blower in producing the requisite pressure in the interior of the hollow bodies he is producing. The simplest of all these consists in utilising the expansive force of the air enclosed in the hollow body when that body is exposed to heat. ”

“ There is a wide choice of apparatus, from a simple mouth-blowpipe and a candle flame to a power-driven blower and a multiple-jet heating device. All are useful, and all have their special applications, but, for the present, we will consider the ordinary types of bellows and blowpipes, such as one usually finds in a chemical or physical laboratory.
The usual, or Herepath, type of gas blowpipe consists of an outer tube through which coal gas can be passed and an inner tube through which a stream of air may be blown. Such a blowpipe is shown in section by Fig. ”

“ Take the blower off and twist newspapers in loose rolls and put them in the bottom of the grate. Lay kindlings crosswise on top of the paper with spaces for draughts in between. Put coal on top of the kindlings. When the fire is wanted, put the blower on, and light the fire from below. When the coal is well caught, take the blower off. ”

“ THE SUMMER HEARTH.—Summer blowers, of handsomely ornamented iron, are now much used to conceal the empty coal-grates, during the season of warm weather. Like chimney-boards, they render the room very close, by entirely excluding the fresh air that may enter from the chimney. ”

“ The blower repeatedly heats the lower part of the mass of glass and keeps it distended by blowing while he swings it over a deep trench which is provided next to his working platform. In this way the glass is extended into the form of a long cylinder closed at the lower end. ”

“ Where the pressure of the current produced exceeds a quarter of a pound on the square inch the waste of work becomes so great as to preclude their use. The fan is not the most economical form of blower, but it is simple and inexpensive, both in first cost and in maintenance. ”

“ The effect is to cause a movement of the air in the pipe, with the result that a fresh supply is drawn in through the annular opening at C, C, and a continuous stream of air passes along the pipe. This is the form of blower made by Messrs Meldrum Bros. of Manchester, and is largely used for delivering air under the fire bars of boiler and other furnaces. In some cases the jets of steam are allowed to enter a boiler furnace above the fire, thus inducing a current of air which helps the chimney draught and is often used to do away with the production of smoke ”

“ Since I last had the pleasure of seeing you, I have examined the workings in the Wall's-End collieries by the lamps, and have tried them in various explosive mixtures.
On Sunday, I went with Mr. Buddle to your blower, with the single lamps furnished with small tin reflectors. This simple modification rendered them perfectly safe, even in the furious blow-pipe, and at the same time increased their light. Nothing could be more satisfactory than all the trials. ”

“ Before starting the job they rigged an air hose underneath the generators to blow the fumes away from the man spraying. A high-compression blower was placed so that it would exhaust foul air through one of the two open doorways. ”

“ The current of air ought to be constant, uniform, and sufficiently powerful to carry the flame in its direction. When it is not strong enough to produce this effect, it is necessary to add weights to the bellows or the bladder, according as the glass-blowers’ table or our lamp is employed. The point to which you should apply, in the use of these instruments, is to enable yourself to produce a current of air so uniform in its course that the projected flame be without the least variation. ”

“ One can not always camp in the immediate vicinity of water. The best matches are the old-fashioned sulphur kind that come in blocks. These should be kept in a waterproof box. In a recent work on camping I saw mentioned a handy contrivance for blowing the fire. It consists merely of a rubber tube with a short metal tube at the end. When cooking with such a small outfit it is necessary to use a small fire, frequently replenished. The blower serves a useful purpose for bringing the fire quickly into action. ”

“ In many works, therefore, air under pressure is supplied to the benches or stages where the blowing is done, and the blowers’ pipes can be coupled to this air-supply by means of flexible connections when required. ”

“ If, by means of a blowpipe with a very fine orifice, you direct a current of air through the middle of the flame, you project a portion of the flame in the direction of the blast. The jet thus formed appears like a tongue of fire, blueish, cylindrical, straight, and very long; the current of air occupies its interior. This flame is enveloped on all sides by an almost invisible light, which, extending beyond the blue flame, forms a jet, A ́ B, very little luminous, but possessing an extremely high temperature. ”

“ With a good blowpipe the air projects the entire flame, forming a horizontal, blue cone of flame, which converges to a point at about an inch from the wick, with a larger, longer, and more luminous flame enveloping it, and terminating to a point beyond that of the blue flame. ”

“ The air is forced through the tube against the flame by the action of the muscles of the cheeks, while he continues to breathe without interruption through the nostrils. Having become acquainted with this process, it only requires some practice to produce a steady jet of flame. A defect in the nature of the combustible used, as bad oil, such as fish oil, or oil thickened by long standing or by dirt, dirty cotton wick, or an untrimmed one, or a dirty wickholder, or a want of steadiness of the hand that holds the blowpipe, will prevent a steady jet of flame. ”

“ Where gas is not available, an ordinary gasoline blow-torch does very well for all operations requiring a large flame, and a mouth blow-pipe arranged to blow through a kerosene flame does well for a small flame. Several dealers make blow-torches for oil or alcohol which are arranged to give a small well-defined flame, and they would doubtless be very satisfactory for glass-work. Any good bellows will be satisfactory if it does not leak and will give a steady supply of air under sufficient pressure for the maximum size of flame given by the lamp used. ”

“ Having produced a red-hot spark and set fire to my tinder, I want you to see what I do next. I set to work to blow upon my lighted tinder. You remember, by the bye, that Latin motto of our school-books—alĕre flammam, nourish the flame. When I blow on the tinder my object is to nourish the flame. Here is a pair of common kitchen bellows (Fig. 25) ; when the fire is low the cook blows the fire to make it burn up. What is the object of this blowing operation? It is to supply a larger quantity of atmospheric oxygen to the almost lifeless fire than it would otherwise obtain. ”

“ Fun blowing glass bubbles. Smooth one end of a piece of No. 2 tube and allow it to cool. Close the other end in the blowpipe flame, turn it slowly, and heat until it is very hot. Take the tube out of the flame, put the smooth end into your mouth quickly, and blow as hard as you can (Fig. 11) . Do you get a fine big glass bubble which bursts with a pop?
7If you get only a small bulb at the first trial, heat the end, and try again. Do you find that the bulb shrinks when heated but blows out again readily? ”

“ Two or three men seize the nozzle of the great hose and rush with it into the burning [Pg 173] building to seek the heart of the fire. Smoke pours from the doors and windows in dense clouds, blinding and choking them until they gasp for breath. Water slops and spatters everywhere, steam rises from the blazing timbers, and the intense heat scorches and stifles them as they work. ”

“ A long and pointed tongue of fire extended itself from the flame of the candle. Monsieur Roger placed close to this tongue of fire the tapering and open end of the tube in which the water had finished boiling. The air, forced out of the blowpipe and thrust upon the flame of the candle, bore to this flame a considerable quantity of oxygen, which increased the combustion and produced a temperature high enough to soften and melt the open extremity of the tube, and so seal it hermetically. ”

“ He exhibited a chandelier ‘in the form of a long flexible tube suspended from the ceiling communicating at the end with a burner, designed with much taste, being a cupid grasping a torch with one hand and holding the tube with the other.’ He explained how the form of the flame could be modified, and demonstrated that the flame was not liable to be extinguished by wind or rain, that it produced no smoke, and did not scatter dangerous sparks. ”

“ FIG. 4.
The common bellows is the most familiar form of blowing machine. It consists of two boards bound together with leather, having folds so arranged that the upper board may be raised or depressed, and the whole is made air-tight; in the lower board is a hole with a leather flap-valve opening inwards. When the upper board is raised, the air rushes in at the hole, pushing up the valve, and when the board is lowered the air presses the valve down, and so shuts it close, it has therefore no exit but at the nose of the bellows, from which it passes out. ”

“ It is used in some Turkey red dye-works. Blood is a powerful manure.
[150]
BLOWING MACHINE. See Iron, Metallurgy, Ventilation.
BLOWPIPE. (Chalumeau, Fr.; Lothröhre, Germ.) Jewellers, mineralogists, chemists, enamellers, &c. make frequent use of a tube, usually bent near the end, terminated with a finely pointed nozzle, for blowing through the flame of a lamp, candle, or gas-jet, and producing thereby a small conical flame possessing a very intense heat. Modifications of blow pipes are made with jets of hydrogen, oxygen, or the two gases mixed in due proportions. ”

“ The products of combustion of the fire A, rise up between two brick walls, so as to play upon the bed of tiles B, where, after communicating a moderate heat to the series of slanting pipes whose areas are represented by the small circles a, a, they turn to the right and left, and circulate round the successive rows of pipes b b, c c, d d, e e, and finally escape at the bottom by the flues g, g, pursuing a somewhat similar path to that of the burned air among a bench of gas-light retorts. ”

“ When it is found necessary to blow a fire, do not thrust the nose of the bellows between the bars, but keep it at an easy distance from the fire, and rather below the centre of the fire, that so, the air may be dispersed around to a considerable distance in front of the fire. When you stir a fire, always put the poker between the second and third bars.—After you have stirred the fire, rake out the ashes at the bottom of the grate, and sweep up the hearth. ”

“ The flame and heated air ascend to the top of the fire-place, and pass into two hollow pillars or piers, which rise to a height of five or six feet, so that the heat is communicated to a large surface, before the volatilized products of combustion make their exit by a pipe into the chimney. ”

“ When the fire operates inside the tube it is called a flue. A tube carries water; a flue carries flame and the volatile products of combustion.
Boilers, or steam generators, that are used to contain the water which, when converted into steam, drives the engine, require to be sufficiently strong to withstand an internal or bursting pressure. ”

“ Take a clay pipe, fill up with cotton wadding loosely and keep in place at mouth of bowl by a wire screen. Wet cotton with gasoline. Let the bubbles float in air and light them with candle, and they will explode with a big flame. Smoke-bubbles may be made by blowing in smoke after the bubble has been well started.
Rebounding Bubbles. A good game is to have a small sheet held by a number of children and blow the bubbles upon this, then they can be sent flying by drawing the sheet taut. Many ways may be devised to make blowing soap-bubbles attractive. ”

“ Some ignited bodies are found to be much warmer than some flames; for instance, red hot iron is much warmer, and burns more than the flame of spirits of wine. 26. Some bodies even not ignited, but only heated by the fire, as boiling water, and the air confined in reverberatories, surpass in heat many flames and ignited substances. 27. Motion increases heat, as is shown in the bellows and the blowpipe; for the harder metals are not dissolved or melted by steady quiet fire, without the aid of the blowpipe. 28. Let an experiment be made with burning-glasses ”