US 989270 A
Description (OCR text may contain errors)
J. H. LESTER & E. C. MILLS.
STEAM BOILER. APPLICATION FILED APR. 2. 1910.
' Patented Apr.11,1911.
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I To all whom 'it may concern:
UNITED STATES PATENT oEEroE.
JOSEPH HENRY LESTER, 0F ECCLES, AND EDGAR CONIS'ION IVIILLS, 0F MANCHESTER,
Specification of Letters Patent.
Patented Apr. 11, 1911.
Be itknown that we, J osnrrr HENRY LEs- TER, analytical chemist, and EDGAR CON ISTON MILLS, consulting mechanical engineer, subjects of the King of the United Kingdom of Great Britain and Ireland, and residents, respectively, of Eccles and of Manchester, in the county of Lancaster, England, have invented new and useful Improvements in Steam-Boilers, of which the following is a specification.
Our invention consists in the main of means whereby the water to be heated and evaporated is compelled to travel upward absorbing heat in its ascent from surfaces obtaining their heat from the gases of combustion which are compelled to travel in the contrary or downward direction. Thus the hottest gases are contiguous to and yield heat to the hottest water and the cooled gases are contiguous to the cooler water near its entrance to the boiler shell at its lower The most convenient form of construction is to provide a cylindrical water shell having a vertical or approximately vertical axis and to pass the gases through fire tubes parallel with the axis of the shell and secured into tube plates at their ends.
In order to compel the water to travel mainly in .an upward direction we divide the water space 1nt0 two or more compartments by horizontal divisions allowing only 'small annular passages around the tubes,
and in some cases we extend the said annular passages by placing a larger tube around each fire tube for a portion of its length.
The upper tube plate is preferably in the form of an inverted cone and forms part of or is attached to a combustion chamber provided with an opening from a firebox placed at right angles to the axis of the boiler shell, such chamber being immersed in the water at a suitable depth below the water level and provided with a bolted lid. The lower tube plate forms the top of a smoke-box which is connected by a suitable pipe with the main outlet flue.
The general construction somewhat resembles that of an ordinary locomotive boiler but placed on end with its smokebox at the lowest point. The upper part of the shell may be extended at right angles so as to embrace the firebox 'or the firebox may be external.
In order to obtain access to the tubes for cleaning them or for renewal, we form the before-described combustion chamber as a separate piece from the tube plate but bolted or riveted to it. It is similarly secured to the throat leading from the firebox. The top of the shell forms the steam space or dome and is closed by a flanged and bolted lid. When this is removed and the combustion chamber lid also removed, access is ob-.
tained to the tubes and they can be repaired or renewed.
In large boilers the tubes can be cleaned from the chamber by means of jointed rods or by steam or air scour. The tubes being vertical the dust falls right through them into the smokebox but in order to provide a free course for it we place a large area tube in a central position, the outlet from which at the bottom can be throttled as desired orv closed altogether by a suitable adjustable stopper. In such a boiler there is of course a great difi'erence in temperature between the bottom and the top. Such a difference in a horizontal boiler would set up destruc-f tubes is disposed at right angles to such zones there are no unequal tensional or bending strains resulting from differences of temperature. An important feature of our invention is this vertical form in combination with the counter-current system hereinbe fore described. Referring to the drawings which form a part of this specification, Figure I is a general sectional elevation of one form and method of constructing a steam boiler in accordance with our invention and in which the firebox or furnace is external to the boiler. Fig. II is a sectional elevation of part of a steam boiler showing a modification of our invention by which the whole of the internal tubes can be'removed for inspection cleaning or repair and also showing extended annular water passages around the firetubes. The same figure shows the upper part of a boiler made in accordance with our invention and in which the furnace is internal and immersed.
The same reference letters denote the same parts in each figure.
A is the outer boiler shell which is preferably made of comparatively small diameter in its lower portion a, enlarged.
conically at a, and of larger diameter in its upper portion at a It is closed by a suitable strong cover a bolted or otherwise secured to the shell A. It is formed with one or more openings as shown at a a short distance above the enlargement, and the combustion box B, which has also a branch or throat b, is attached to the shell so that the throat 6 corresponds with the opening a of the shell, and is secured to the shell by rivets or bolts. In Fig. I a flange 0 formed on the throat tube 6 is shown attached internally to the shell and to the box B by the flange 12 formed with the tube Z). This method of construction allows of the removal of the box B when the top of the shell is removed and the rivets or bolts of the throat flange are withdrawn. The box B may have a dome shaped top formed with the box and it may be provided with a cover or lid 6 bolted to the box as shown in Fig. I. b is the upper cone shaped tube plate which in Fig. I is shown riveted to the box B. In both figures O C are the vertical firetubes expanded or suitably secured at their upper ends to the tube plate I) and at their lower ends to the tube plate d, which in Fig. I is shown secured by its edge flange to the ring d and so to the shell A, but in Fig. II it forms the upper end of an internal immersed smoke box D.
The water space in the lower smaller part of the shell A is divided into two or more compartments by the horizontal divisions shown at E E. In Fig. I these are shown as mere plates having small annular spaces or passages around the tubes C, but in Fig. II the plates E carry the outer tubes F F extending for a suitable length along the firetubes C, and allowing an extended nar row annular water space by which alone the water can pass from below to above the plate E.
The construction of the internal immersed smokebox D as shown in Fig. II in conjunction with the described attachment of the combustion box B is for the purpose of facllitating the removal occasionally of the whole of the internal parts, namely combustion box, firetubes and smoke box, for the proper inspection of the inside of the shell. I
In boilers in which the outer tubes F F are used the plates E are detached to allow themv and the said tubes F to come out along with the fire-tubes C.
The central firetube 0 is preferably made of larger diameter to allow for the passage of flue dust, and an adjustable stopper or plug (Z is provided to admit of the said flue dust being extracted and to prevent too free passage of the hot gases.
In the form shown in Fig. I the whole space D below the tube plate (Z forms the smoke-box and from it an outlet (1 provided with damper d connects to the common main flue N leading to final or chimney outlet. The cleaning-out door al is for the purpose of extracting the flue dust and the like and for access to the lower tube plate for repairs.
The feed water inlet is in the lowest available position and is preferably multiple, thus in the drawings four inlets are provided, two of which are shown at H H in Fig. I. The blow-out connection is placed at the lowest available position. The pipes leading therefrom are shown at I in Fig. I with valve 6 and the opening is shown at 2' in Fig. II. In Fig. II the openings from the smokebox D are shown formed through both the smoke box plates and the plates of the shell A which are suitably bulged to come together and are riveted or bolted to form one opening.
The external furnace and details of its construction form no part of the present invention, but two or more of the throat openings for furnaces each provided with a furnace may be formed at varying positions radially around the shell and each connected to and delivering into the central combustion box B.
The form of our invention in which an internal furnace is used is also illustrated in Fig. II. The top of the shell A is shown at a. The horizontal cylindrical shell a is riveted or bolted to a by the downward opening formed in it as shown at a. At its longer or outward end an opening a iS formed. The cylindrical inner tube G, open at one end and closed at the other and having also a downward opening 9, is riveted or otherwise secured in the opening a and to the opening 9 the top tubeplate is riveted or bolted. Thus the upper part of the boiler is of the form known as Gornish but with the gases outlet downward and tubular. The pit M in this case is provided merely to catch any fuel, ash or clinker passing over the first bridge 0, and they can be removed by the passage closed by the door 0.
Any suitable furnace front, for handfiring or mechanical stoking, can be attached to the open end of the tube G. Having now described our invention and in what manner the same is to be performed we desire to state that weare aware that steam boilers have previously beenmade in which vertical downward flow firetubes have been used in conjunction with immersed combustion chambers above and in which unrestricted or rapid water circulation has been allowed or promoted in the water space or shell.
What we claim as new and desire to secure by Letters Patent is 1. In a vertical steam boiler, vertical firetubes, a furnace and immersed combustion chamber above the fire tubes, the smoke box at the lower ends of the fire tubes and the outer shell provided with horizontal divisions for restricting the water space and into which shell the feed water is introduced at its lowest point, whereby the essential principle and action of vertical counter current is secured substantially as described.
2. In a vertical steam boiler, vertical fire tubes, a combustion chamber above them, a smoke box below them, the said vertical fire tubes being secured to the tube plate of the combustion chamber and to the tube plate of the smoke box, and an outer shell provided with horizontal divisions of the water space, allowing only small annular passages for the water around the said vertical tubes substantially as described.
3. In a vertical steam boiler, vertical fire tubes, a combustion chamber above the tubes, a smoke box below the tubes, the said fire tubes being secured to the tube plate of the combustion chamber and to the tube plate of the smoke box, and an outer shell provided with horizontal divisions of the water space, the outer vertical tubes being attached to said horizontal divisions allowing only small annular elongated passages for the water around the tubes substantially as de scribed.
4. In a vertical steam boiler, vertical fire tubes, an immersed combustion chamber above the tubes, an independent immersed smoke box below the tubes, and an outer shell provided with horizontal divisions of the water space to limit circulation, the said combustion chamber and smoke box being detachable from the shell for removing them bodily with the tubes substantially as described.
5. In a vertical steam boiler, vertical downward current fire tubes, an outer shell provided with horizontal divisions of the water space to limit circulation, and an immersed combustion chamber in co-active relation to the vertical tubes and horizontal divisions and having a detachable cover substantially as described.
(3. In a vertical steam. boiler, vertical downward current fire tubes in combination with horizontal divisions of the water space for limiting circulation, the central fire tube being larger than the surroundim tubes and provided with an adjustable plug at its lower end substantially as described.
7. In a vertical steam boiler, vertical downward current fire tubes in combination with horizontal divisions of the water space to limit circulation, an outer shell the upper part of which is extended at right angles to the vertical part, and an immersed fire box or furnace embraced by the shell substantially as described.
In testimony, that we claim the foregoing as our invention, we have signed our names in presence of two witnesses, this twentythird day of March 1910.
JOSEPH HENRY LESTER. EDGAR CONISTON MILLS.
WILLIAM CLUNAL-LEES, RUTH MAGDALENE WILSON.
Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.