US576874A - Q o o o o c - Google Patents

Description

(No Model.) 2Sheets--'Sheet 2. r

R. W. MEWES.-

STEAM GENERATOR.

' No. 576,674. Patented Feb.9,1897.

UNITED- STATES PATENT ()FFICE.

RICHARD VATSON MElVES, OF BLACKHILL, ENGLAND.

STEAM-G EN ERATO R.

SPECIFICATION forming part of Letters Patent No. 576,874, dated February 9, 1897. Application filed October 15,1396. Serial No. 608,949. (No model.) Patented in England August 14, 1894, No. 15,490.

To all whom it may concern:

Be it known that I, RICHARD WATSON MEWES, a subject of the Queen of Great Britain, residing at Blackhill, in the county of Durham, England, have invented new and useful Improvements in Steam-Generators and Water-Heating Boilers, of which the following is a specification, and for which I have received Letters Patent in Great Britain, dated August 14, 1894, No. 15,490.

My invention relates to steam-generators and water-heating boilers and is applicable to the several types of construction employed for stationary, locomotive, or marine purposes.

It is among the objects of my invention to provide for completely surrounding the furnace or fire-box with water and to carry the fire on a dished plate forming the bottom of the fire-box. The bottom of the boiler-shell is to be concavo-convexed to correspond with the dished fire-box bottom and thus provide an intermediate bottom water-space so formed that the steam and heated water may more readily escape into and through the waterspace around the sides and top of the fire-box. As a means for carrying ofi ashes to the ashpit and supplying the fire with air to support combustion a large number of tubes are distributed over the entire bottom surface of the fire-box and extended through the waterspace between the furnace-bottom and the bottom of the boiler-shell, where they open into the ash-pit beneath. By this construction fire-bars are dispensed with, the air is heated before entering the fire-box, and the tubes are made to act as stays for the furnace and boiler-shell, besides serving as passages for air and ashes, and being wholly surrounded by water they cannot burn out. These tubes for the passage of hot air and descent of ashes are preferably ferruled in their upper ends to form an internal cone that is gradually enlarged downward for a sufficient distance to quickly and easily release the ashes and prevent choking or clogging. Other objects of my invention will be apparent from the features of construction and novel arrangement of parts as hereinafter described.

In the annexed drawings, illustrating the invention, Figure 1 is a transverse sectional elevation of a vertical steam-boiler embodying my improvements. Fig. 2 is ahorizontal section of the same above the bottom of the fire-box. Fig. 3 is a vertical longitudinal section of the fire-box end of a boiler of the locomotive type constructed according to my invention. Fig. 4 is a sectional end view, and Fig. 5 a sectional plan, of the same. Fig. 6 is a transverse sectional elevation of the furnace end of a boiler with two flues leading from the one furnace that is common to both said flues. Fig. '7 is a vertical longitudinal section of the same. Fig. 8 is a transverse vertical section of another type of boiler to which my invention is applicable. Fig. 9 is a vertical longitudinal section of the furnace end of the same. Fig. 10 is a vertical section, and Fig. 11 a half sectional plan, of another type of steam boiler to which my invention is adapted. Fig. 12 is an enlarged sectional detail view of portions of the bottom plates of the boiler-shell and the inclosed fire-box, showing one of the air and ash tubes with ferrule in its upper end to quickly release the ash that enters the tube.

In each of the several figures of the drawingsthe reference-numeral 1 designates the boiler-shell, and 2 the furnace or fire-box, so constructed and arranged relatively to each other as to provide a continuous water-space on all sides, whereby the fire-box is completely surrounded by water. The bottom 3 of the boiler-shell and the bottom 4 of the inclosed furnace or fire-box are each dished or correspondingly concavo-convexed and are placed a sufficient distance apart to afford a water-space 5 between them, which communicates with the water-space that surrounds the sides and top of the fire-box. The furnace is constructed without fire-bars, and the fuel is placed directly on the dished firebox bottom. It will be seen that with this construction the concavo-convex form of the bottom water-space 5 will facilitate the escape outward and upward of steam generated by the heat transmitted through the furnacebottom. This bottom water-space 5 is traversed by a number of tubes 6, which supply air to the furnace for supporting combustion of the fuel. These air-tubes 6 are either screwed or expanded into the two bottom plates 3 and 4 of the boiler-shell and fire-box, respectively, and they may be ferruled or purposes.

coned at their upper ends, so as to facilitate the discharge of ashes into the ash-pit '7 below; but though these tubes may be conical, with their smaller ends next the fire to facilitate discharge of the ashes to the ash-pit, I prefer to make them straight or with parallel sides and to ferrule the ends next to the fire, as shown in Fig. 12. The fire is supplied with fuel and stoked through the ordinary fire holes, and the refuse ashes fall through the tubes 6 into the ash pit or pan.

The combustion is "cry superior, because the tubes 6 being distributed over the entire furnace-bottom and the air having once entered the tubes it must go direct to that par ticular part of the fire to which a tube leads, thus insuring uniform heating over the whole fire-box. Renewal of the tubes 6 will not be often required, as is the case with fire-bars, because being entirely surrounded by water, which is also in contact with the plates 3 and at, both the tubes and the said plates willnot be liable to get overheated. Thus the heat that is lost in burning out fire-bars in other furnaces goes directly to heat the water surrounding the tubes 6 in this boiler or steamgenerator. Moreover, the air to support combustion in passing up the tubes 6 gets heated before entering the furnace, and therefore cannot exercise any cooling effect on the most important part of the heating-surface. Thus the combustion of fuel in the fire-box is made so perfect and complete that nothing but fine ash falls through the tubes 6, which is not worth burning over again and does not stop up the tubes. It will be seen, therefore, that the tubes 6 serve a number of highly useful They carry refuse ashes to the ash-pit, they admit air into the fire-box for combustion and heat it before it enters the fire-box, they act as stays to the furnace and boiler-shell, and they dispense with firebars. It will be obvious also that the dishing form of the bottom plates 3 and 4 will give greaterstrength. A number of the tubes 6 may be tapped into these plates and the rest expanded, thereby further contributing to their efficiency as stays.

There can be nosettling of sediment on any part of the bottom hcating surface provided by the dished fire-box bottom 4, all the sedimentfalling onto the shell-plate 3 underneath the fire-box, where it can do no harm. It is found also that the heat in the bottom waterspace 5 is so great that the sediment is kept in constant agitation and will be readily carried off by any suitable cock provided for that purpose.

The fire-box in vertical boilers, as in Figs. 1 and 2, may taper upward to the crown, and from the crown tube-plate will be extended fire-tubes S, forming fines through the water and steam space of the boiler to a tube-plate 9, that forms the top of the boiler-shell, and upon which may be supported a smoke-box leading to the chimney.

Across the furnace or fire-box is preferably arranged a somewhat conical water-tube 10 to spread the flame and gases, increase the heating effect, and promote circulation of the water.

A series of horizontally-arranged air-tubes 11 may be inserted between the boiler-shell and the furnace to open above the fuel and supply air for consuming smoke with certain kinds of fuel.

Referring to Figs. 3, 4, and 5, showing a boiler of the locomotive type, the boiler-shell 1 and the inclosed firc-box 2 are cylindrical and have the crowns of each partially domed, so as to dispense with'staying except for very high pressures, and the back of the furnace is formed with a flat tube-plate for the ends of the fire tubes or flues 8, which are here arranged horizontally. The bottom of the firebox and that portion of the boiler-shell beneath are dished, as before described, forming a concavo-oonvexed bottom water-space 5, through which the air and ash tubes 6 are extended. Locomotive boilers constructed upon this principle possess many obvious advantages in their ability to travel a greater distance with the same quantity of fuel, a greater horse-power for the same size of boilershell,1ess cost in repairs,and largely-increased durability.

The construction of boiler shown in Figs. (3 and 7 resembles the Lancashire type, the furnace 2 forming an oval chamber from which two fire-flues 8 traverse the length of the boiler-shell. The furnace may he stayed by a conical water-tube 10, arranged verticall y. The bottom water-space 5 is traversed by air-tubes 6, which in this case are shown conical to facilitate discharge of ashes into the ash-pit below.

As applied to boilers of the marine type with two or more furnaces an ash chamber or chambers will be constructed in the seatin g of the boiler, into which the series of airtubes will open, and fire-bars being dispensed with the furnaces may be of much smaller diameter than usual, as may also the shell of the boiler.

In Figs. 8 and 9, showing my invention applied to the Cornish type of boiler, the furnace 2 is of slightly oval section to suit the fixing of the air-tubes 6 through the bottom water-space. A single fire-flue 8 is extended from the furnace backward through the boiler shell.

It is well known that in raising steam from cold water in horizontal boilers the boiler may be steaming at the top while the water under neath the furnace is cold, so that there is undue expansion of the plates, and this occurs every time the fire is lighted up, thus causing the rivets and seams to be strained. This objection is obviously avoided in my invention by reason of the water being heated simultaneously all over the fire-box, at bottom, sides, and crown, instead of at the sides and crown only, as in ordinary boilers. Again, the heating-surface of the fire-box being double that IIO of ordinary boilers it is not necessary to have the furnace so large, thus afiordin g more water and steam space, or, if desired, the boiler-shell may be made smaller.

Figs. 10 and 11 show a form of boiler construction in which the back of the furnace 2 is gathered inward to provide a flat tube-plate for attachment of short horizontal tubes or fire-fines 8, opening into a smoke-box 12, attached to the boiler-shell.

In all the forms of boiler construction shown in the accompanying drawings and in other types of boilers to which my invention is applicable the bottom water-space 5 is made 'concavo-convex, and the tubes 6, traversing said space, are adapted to securely stay the fire-box and boiler-shell, besides supplying heated air to every part of the fire and permit a free discharge of ashes to the ash pit or pan. For water-heating boilers as applied for various purposes the boiling of the water is very rapid, owing to the large heating-surface of the bottom being in immediate contact with the burning fuel and the air being so thoroughly distributed among the fuel,while in steam-boilers a considerable increase of evaporation will be effected from this surface, and the absence of fire-bars relieves the boiler of a very considerable Weight, besides avoiding the expense and trouble of replacing wornout or defective bars. A very large saving of fuel, perfect circulation, and rapid generation of steam are other valuable features.

As clearly shown in Fig. 12, I prefer to make the air and ash tubes 6 perfectly straight or cylindrical, and in order to prevent choking or clogging of these tubes with ashes I insert into the upper end of each tube a ferrule 14, having an external diameter that will tightly fit the tube and an internal diameter or bore that is enlarged from above downward, so that ashes entering at the top are easily and quickly released and allowed to fall freely into the ash pit or pan without any liability of clogging and stopping up the tubes. The ferrules 14 can be produced very cheaply and easily by being swaged on a taper-mandrel or turned in a lathe. By means of these ferrules 14 the ashes are released and have increased room to fall as soon as they enter the tubes, and consequently there can be no choking or clogging. WVhat I claim as my invention is 1. In steam-generators and water-heating boilers, the combination with the boiler-shell and inclosed fire-box, each having a dished bottom to form an intermediate concavo-convexed bottom water-space, of a number of conical or tapering air-inlet tubes extended across said bottom water-space and opening into the fire-box and ash-pit, the larger ends of said tubes, being downward to quickly discharge the ashes into the ash-pit, substantially as described.

2. The combination with a boiler-shell, and an inclosed fire-box completely surrounded by water and having a water-space between the bottoms of said boiler-shell and fire-box, of a number of tubes traversing said bottom water-space and connected with the bottoms of the fire-box and boiler-shell to supply heated air to the fire and discharge ashes to the ash-pit, and conically-bored ferrules in serted into the upper ends of said tubes with the larger ends of the ferrule-bores downward to quickly release the ashes entering said tubes and thereby prevent choking, substantially as described.

3. The combination with a boiler-shell, and an inclosed fire-box completely surrounded by water, there being a water-space between the bottoms of the said boiler-shell and firebox, of a number of tubes traversing the said bottom water-space and connecting the bottom plates of the fire-box and boiler-shell to afford passages for air and ashes, conicallybored ferrules inserted into the upper ends of said tubes with the larger ends of the ferrule-bores downward to quickly release the ashes and allow them to discharge freely, and a series of lateral air-inlet tubes above the fuel-bed, substantially as described.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

RICHARD WATSON MEWES.

"Witnesses:

GEORGE GREY, ABRAHAM BEWIOK GOLDSHOUP.

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