US119185A - Improvement in feed-water apparatus for steam-boilers - Google Patents

Description

WILLIAM C A. H sELnI-:N Improvement inyFeed-Water Apparatusfor Steam Boilers.

Patented Sep. I9; I87I.

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UNITED-'STATES 1 PATENT rieuse FFICE.

W ILLIAMJO; VSELDEN, vOF BROOKLYN, `NEW YORK.

Specification forming part of Letters Patent No. 119,185,7dated September 19, 1871.

To all whom it 'may concern: i Beit known that I, WILLIAM C. SELDEN, of Brooklyn, county of Kings, in the State of' New `York, have invented certain new and useful Improvements in the Feed-Water Apparatus of' Steam-Boilers; and I do hereby declare that the following is afull and exact description thereof', reference being had to the accompanyingdrawing making part of this application.

It is a well-known fact :that in th'e use of' salt Water for the purposes of' steam generation 4the saline deposits and incrustation on the surfaces of' the boilerare serious objections and to overcome the difficulties encountered in the use of salt water in marine boilers it has been customary to employ a supply of fresh water, (or distilled salt water.) Since, however, it is not practicable to carry a sufficient supply of water to permit a constant fresh supply to the boiler, (and an escape of thel exhaust steam,) it has been customary to recouvert the steam, (after it has passed. through the engine,) into water in a surface condenser, and use the same water over and over again. This process has also been applied to stationary boilers in cities, and wherever the consumption of the fresh water used to run the boiler is an item of suflicient expense to induce the economic system of using the water over and over by the condensationgof the exhaust steam back to water, as I have mentioned. Experiment and practice have, however, demonstrated beyond dispute'the fact that, although no material injury is iniiicted on the metal ofthe boiler by the use in it of pure fresh water in the reuse, or in using over and over again the same (distilled) water, (by the process of condensation and reuse I have alluded to,) serious injury occurs to those portions of the boiler which are exposed to the action of the water.` Ithas been demonstrated by experiment that the samekind of water which, when supplied infresh quantities to or passed once through the boiler, has no injurious effect on the latter, will, when used over and over again in the same boiler, soon injure and destroy the What chemical or other change occurs in the condition of the water by the process of successively expanding it finto steam and recon, verting it into water, or what is the cause of' this known effect, is a mooted question with engineers and scientists, and various theories have been advanced on the subject and some remedies for the evil suggested. Some have attributed this effect on the boiler (by the reuse ofthe same `water, which if passed only once through the i boiler would not injure it) to the fact that the water in passing through certain copper or brass i tubes or vessels wears off' by friction and carries in solution the copper or other metal, and

l that by the deposit of such metal in the boiler a galvanic action is induced in the boiler which destroys the iron of' the latter. Others, that some chemical change occurs in the water which induces to this injurious influence on the iron of' the boiler. I am not aware of any perfectly satisfactory solution having been offered yet of the cause or causes of the evil, nor has any successful remedy been suggested to overcome it that I know of. t

` I have learned by experience and experiment that in the use of the system employed for using over and over again the saine water a large quantity of foreign matter, such, for instance, as the tallow or other lubricating material used in the engine, and the metallic wearings of the engine and other parts, must necessarilybe taken up by the water, and that this accumulation of foreign matters must be continually augmented by other accumulations as the water travels over and over again through the boiler, engine, and condenser. I am also aware that bythe process of heating and generating into steam the water is deprived of the air which it contains when in a natural state, so that it will require, after condensation, a greater degree of heat for a regeneration into steam than was necessary when it was in its natural condition. And also, that in the heating of the water the oxygen of the expelled air probably unites with the iron, leaving free nitrogen, which may unite with the hydrogen set free by the decomposition of oxygen in heating the water, thus forming ammonia, Awhich is known to be very destructible to iron.

From these facts and experiences I have concluded that, for the purpose, of reducing the evil effect of the water on the boiler, saving the engine from the ill effects of grinding through it continually a mass of floating foreign matters, and economising in the generation of' the steam, it is important to provide some means by which the water, after it shall have passed through the boiler, engine, and condenser, shall be deprived, as far as possible, of all'extraneous and deleterious substances, and shall be acted upon both mechanically and chemically in such a manner as to put it in a natural and purified condition before it is resupplied to the boiler. And to accomplish these ends I propose to employ, somewhere between the condenser and the boiler, some suitable apparatus, through which the water shall pass and in which it shall be thoroughly filtered to extra-ct all foreign substances; shall be resupplied with the proper proportion of air or oxygen, and shall be supplied with, or deprived of, such chemical qualities as may be necessary to render it incapable of' causing the dificulty which I propose to eifectually overcome, viz., the injurious effect on the iron of the boiler. What sort of chemical treatment precisely the water is to receive will depend upon the nature ofthe water, the character of' the metals with which it is brought into contact, and other con- Y ditions.

My invention consists in subjecting the water to such mechanical and chemical treatment after it has been generated into steam and reconverted into water, or has been once used, and before its reuse in the boiler, as shall purify it and restore it to its natural or former condition as nearly as possible.

To enable those skilled to fully understand my invent-ion, I will describe the mode in which I have successfully practiced it in one or more instances, leaving it to the judgment of the engineer and chemist to vary the details ofl the apparatus and process of treatment as circumstances may require.

In the accompanying drawing is illust-rated an apparatus which I have used in successfully carrying out my invention, and with which very beneficial results have been attained.

Figure l is a top view 5 Fig. 2, a vertical section at s0 Fig. l; Fig. 3, a cross-section at y y, Fig. 2; and Figs. 4 and 5, detail views of the ap' paratus.

A represents a tank or box suitably constructed, and which, when used in connection with marine boilers and engines, should be provided with a removable cover properly iitted on to prevent the contents of said tank being displaced or thrown out by the motion of the ship. This tank A is divided by partitions into a series of compartments, some of which are iilled with filtering and purifying materials, as will be presently ex.- plained. B is an air pump, adapted to force air into a receiver, C, near one end of the tank A, from which it escapes through numerous ap: ertures in the bottom of one of' the compartments of said tank. D is a pipe leading from` the condenser to one end of the tank A, and E is a pipe leading from the opposite end of said tank to the boiler, (or to a reservoir from which the boiler is supplied.) The compartment at F receives the water from the condenser, while the one G next to it is filled with coke.

tion a, between these two compartments, is perforated, as seen, so as to permit the passage of'v water contained in F through it; and on the side adjacent to the compartment F is arranged' The parti- (close to said partition) a filter, b, made of felt. The compartment H is filled with broken chalk or lime, while compartment I is filled (like G) with coke. c and d are 'perforated partitions, similar to a, ande is another (slotted) partition. Between d and c is left a space, which is filled in with wool to form another filter. At f is another felt iilter arranged, as shown, next to the slotted or perforated partition g, and through this filter the water has to pass to supply the compartment J, in which the filtered water is subjected to the action of air blasts, as will be presently described, and from which it is taken on" by the tube or pipe E, to be supplied to the boiler for reuse.

rlhe general operation of this machine or apparatus is about as I will now explain. The water from the condenser passes (continually) through the pipe D and discharges into the compartment F, (which is generally kept nearly f'ull,) and from here passes through the felt filter b and perforated partition a into the compartment G, where it percolates through the mass of coke with which this compartment is filled, and by this means of filtration most or all of' the solid extraneous substances are extracted. From here it passes on through the mass of' chalk or lime in compartment H, where a chemical action will occur to deprive the water of any metals which may be held in solution (and have passed through the felt and coke filters) by rendering such metals solid; and should such solid particles be carried on by the water they will be extracted by the wool filter, (located between d and 0,) and by the coke filter at compartment I, where the water is again subjected to the action ofl a larger quantityof coke. After passing through another f'elt filter, f, the water enters and fills the compartment J, from whence it is drawn oi at pleasure through a tube, E, to supply the boiler. rlhe airpump B being kept in operation in the mean time, atmospheric air is constantly forced into the receiver C, and escaping from thence upward through the perforations l, 2, 3, Ste., in the bottom of compartment J, passes in jets through the body of' water contained in said compartment. By this continuous blast of air through the water in J said water is supplied with its necessary or proper proportion of air. The quantity of air supplied to (or forced through) the water may, of course, be regulated. If expedient, and if' desired to have the action of the air-blast periodical, or intermittent, or its force should be so slight as to require it, the apertures in the bottom of J may be provided with some suitable valve device, to prevent the water from passing down into the receiver G. Not only is the requisite quantity of air mechanically combined with the water by this injection from the air-pump, but a chemical action may occur by the introduction into the mass of water of additional oxygen, by which it will be deprived of any contained ammonia, (by the chemicalunion ofA oxygen with the nitrogen ofthe ammonia;) and thus the injurious effects of this substance, if it exists, in the water will be prevented. In Figs. 4 and 5is shown in detail the construction of one of the ing machine.

felt lters made as I have used them in a work- The iilter here shown is composed of a thick. sheet of felt, b, which is attached around its contour or edges to a metallic frame,

. 11?,.and in the use of theV filter this frame b2, with' its attached sheet of felt, is placed and held (by suitable lugs) so as to be embraced between said frame b2 on one side and the perforated partition-` plate c on the other side, as illustrated. When a removal or changing of the felt is necessary, the frame b2 may be extricated and another with a esh felt substitutedfor it. At Fig. 6 is shown` a modication of the apparatus, in which, in lieu of permitting the water to flow through the iilters and compartments in about a horizontal direction,(as in the apparatus just described,) it is j caused to filter downward or flow through the lters and mineral masses in about a vertical direction'. In this modied apparatus the compartments and iilters are so arranged that the water which is fed in from the condenser through pipe `D `fills the compartment F2, and, flowing over the` top of the solid partition a2, passes down through the felt iilter at b2 into and through the mass of coke in compartment G2. From here it escapes (at the bottom) through an opening or openings at m, and filling up the space between c2 and d2,

Viiows over the top of the latter and thence down,

through the wool filter at e2 into and through the chalk at H2.

partment it escapes through the opening at n, and

iilling up and flowing over the top of f2, passes through the felt i filter g2, thence through the coke compartment I2, and out at o into the air-charg-` From the bottom of the chalk com-` to the necessary processes of ltration, oxygena tion, 825e., in one apparatus and at the same time the necessary mechanical and chemical actions maybe made on the water in separate apparatus and at different times, without departing fromthe spirit of my invention, the gist of which lies in the idea of subjecting the water to the nec-V essary processes to purify it and fit it for use in the boiler v after it has been reconverted from steam and before it is again used for the purpose of generation of steam in the boiler.

It may be found expedient to place in the ap# paratus through which the water is passed some metallic substance, on which any destructive effect the water has a tendency to infiict on metals, may be produced, and the water be thus deprived of its destructive influence before it goes to the boiler again.

I do not wish to be understood as limiting my claim of invention to the use of the apparatus v shown,-or to that. of any particular apparatus; nor to the nature 'of or material used for the lilters; nor to the chemical ingredients and actions to which I have alluded, as each and all of these features in carrying out my invention may be varied 5 but, having explained the method by Which I propose to prevent the injury to the boiler which arises from the reuse of the wat-er, and described the mode inwhich I have successfully practiced my invention with very beneiicial results- What I claim as new, and desire to secure by Letters Patent, is-

The method of purifying the Water and rendering it fit for reuse previous to its return to the boiler, substantially as herein set forth.

Intestiinony whereof I have hereunto set my hand and seal this 22d day of July, 1871.

WILLIAM C. SELDEN. [L. s.]

Witnesses:

J. FELBEL, ALFRED F. GoNKLIN.

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