US2230384A - Semiflash water circulating boiler - Google Patents

Description

Feb. 4, 1941. Q OCONNQR 2,230,384

SEMIFLASH WATER GIRCULATING BOILER Filed Oct. 30, 1937 5 Sheets-Sheet 1 Feb. 4, 1941. c. @CONNOR SEMIFLASH WATER CIRCULATING BOILEVR 3 Sheets-Sheet 2 Filed Oct. 30, 1957 Feb, 4, 1941. c. o'c'oNNoR 2,230,384

SEMIFLASH WATER CIRCULATING BOILER Filed Oct. 30, 1957 3 Sheets-Shale?I 5 xx my 3 R /P/yen Zor;

(idiwZZ 0?'0777@ 73' Patented Feb. 4, 1941 UNITED STATES PATENT OFFICE 4 Claims.

This invention is a steam generator in the form of a semiflash, Water circulating boiler.

An object of the invention is to provide, in general, a construction and arrangement of 5V parts having especially in view the optimal p0- sition of the mud drum and the direct attachment thereto of a bed of declining headers or manifolds whereby to effect a centrifugal separation of sedimentary constituents from the circulating water.

Further, an object is to provide a vertical arrangement of down-corners to the manifold bed and provide straight, unobstructed up-floW water tubes of large lifting area, all with the purpose of high circulation eiiciency.

Also, an object is to provide a Water tube system of very compact form in combination with a set of straight, unobstructed headers which are inclined upwardly to facilitate steam and Water iiow to the steam drum and the rapid circulation therefrom of Water to the downcomers by a thermic, pumping cycle.

An object is to provide a water-tube boiler in which the down-comers are placed most remote from the rire-box and in which the tubes are so stood that an even temperature is elected since the hottest water rises in the tubes most remote from the r'e--box and the coolest moves down the foot manifolds toward the mud drum and to the tubes nearest the fire-box so that all tubes generate evenly and eliminate congestion. By this arrangement and construction steam pockets are created to aid in forcing slugs of water up the tubes and into their' header mani- 3.; folds and rapidly drive the water slugs into the steam drum where an instant separation of water and steam is permitted; the water again gravitating and cyclically moving into the downcomers.

40 An additional object is to proide for quick separation of steam bubbles from the hottest sides of the tubes by arranging these in a position inclining upward and toward the fire-box so that the water lies along and travels upward on the nre-box side of the tubes and the stream of steam bubbles off-shoots or rebounds toward cooler, far side of each tube; the advantage being that the water bears to and rises along the hot side and the steam bubbles separate to and lift 5o on the upper, far side of the inclined tubes; the several tubes being substantially upright but not vertical.

The invention provides a boiler which will not steam bind; in which minimum heat is applied 55 to down-corners; in which the water is not subjected tomaximum heat until it has Well raised in the upright tubes, and which is especially free from ebullition and foaming disadvantages.

Further, an object is to provide automatic water and fuel controls in combination with the 5 boiler.

And further an object is to promote eiciency in this class of invention by an efficacious arrangement of pre-heaters for the Water and super-heaters for the steam. 1C

Figure 1 is a vertical, axial section of the boiler unit.

Figure 2 is a schematic diagram of the automatic hook-up of the boiler. Figure 3 is a sectional elevation of the circulating components of l5v the boiler, With its water pre-heater. Figure 4 is an end elevation of the down-comer and steam drum assembly. Figure 5 is a partial end elevation of water tube and mud drum assembly. Figure 6 is a detail sectional plan of a small 20 group of the Water tubes and their foot manifolds. i

In the boiler of this invention cold Water enters by pipe 2, Fig. 3, for flow through the upper1 pre-heating coil 3 in a smoke or gas outlet box 25 4 having an` entrance 5 below a shelf I in which a lower, pre-heating coil 1 is exposed to the incoming hot gases. Coil I is connected to a stand pipe 8, in the smoke-box 4, and joins a cross pipe 9, above the box, having a suitable 30 valve I0 and a check valve II from which a water nozzle I2 extends and is welded into the near side of a horizontal steam drum I4.

From the bottom of the drum I4 there extends a double row 'bank of down-comers I5 and I6. 3 The row of down-comers I5 have their up-ends Welded into the bottom of the steam drum I4 in a line to the right of the vertical diameter oi the drum and extend down in a reverse S- bend and are welded at their lower ends to the 40 ends of relative bottom headers or manifolds I8. The down-comers IS are of S-shape and are welded at their upper ends to the bottom of the steam drum I4 in a line to the left of the vertical diameter of this drum. By this staggered arrangement of the oppositely curved down-comers Iii-I5 there isI ample space for efficient gas ow and heat transfer to the descending Water column in the conduits; the zigzag Welded joints along the bottom of the steam dum is conducive of strength in the combination, and the curvature of the down-comers provides for, normal expansion and contraction axially. y

The down-comers are bent only in one plane and therefore have opposite, parallel sides which are so spaced in the bank to provide good gas flow and surface exposure.

For the purpose of accelerating water cycle periods the bed of water manifolds I8 is materially declined from their junction with the down-comers I5-I5 toward their common, transverse mud drum I9 to which the lower ends of the manifolds I8 are welded along the upper, adjacent quarter-circle of the cylindrical drum wall. By such an inclined arrangement of the bed of water' manif-olds I8 the velocity of the water downward toward the mud drum, it being the lowest element in the Water cycle, tends to cast heavy solids progressively along the water courses' in the bed and ultimately into the -mud drum I9; this being provided with `a suitable blow-out connection 20.

The bed manifolds I8 are shown as of about the same diameter as the down-comers I5-I6 and are joined thereto by angle, butt welds, Fig. 3.

A feature of the invention is the provision of a stand of nearly upright water tubes of which a compact assembly is fixed along each of the bed manifolds I8, and each assembly is closely interracked with the next laterally adjacent assembly. Each such assembly comprises a straight or central row of tubes 22, Figs. 5 and 6, welded at the lower end of each on the top-most surface of its respective foot manifold I8, in suitably spaced setting along the same.

Along the sides of each manifold IB are directly opposite rows of out-set tubes 23 and 24 on the transverse plane medially between adjacent tubes 22 on the same manifold I8. The tubes 23 and 24 are straight throughout except for short incurved ends where they are welded to the upper, lateral portions of their basal manifold, and at their upper ends as later described.

The upper end of each tube 22, of a row, is abutted and welded to the bottom of a respective header manifold 25 of which there is a `deck containing one for each, vertically below, bed manifold I8; the deck being inclined substantially parallel to the latter. The upper end of each tube 23-24 is curved inward toward and welded to the near side of the lower surface of its relative header 25.

The assembly rows of tubes are so staggered that a row of tubes 24 will vertically rack with an alined row of tubes 23 of 'the next adjacent assembly on either side, Fig. 5, thereby presenting a compact and highly eflicient vertical area to the hot .gases and yet providing ample flue-way toward the smoke or stack box 4 at the horizontally remote end of the general organization.

The upper and lower manifolds are of about the same diameter and are of straight and wholly unobstructed flow bore; the lower ends of the headers 25 having clean-out plugs and their upper ends being welded to the near side of the steam drum i4 at the plane of its horizontal axis, which, also, is the normal water line or level of the boiler, and this line or level extending well laterally into the bores of the headers 25. This effects early separation of the steam from the slugs of water moving upward in the inclined headers and substantially eliminates ebullition in the steam drum.

In the top of the steam drum I4 are xed safety valves 2l and a main steam pipe line throttle Valve 28 from which the steam line 29, Fig. l, is extended forward to a lire-box 30.

The steam line is split into two, super-heating helices 3I-32 which are closely meshed along the internal wall surface of the conical fire-'box 30 to receive full benefit of convected and radiated heat from flame of fuel at a burner 33. The steam coils 3 I-32 end close to the stand of water tubes 22-23-24, the foremost of which are exposed to directly radiated heat. The super-heated steam is taken from the coils by lead-outs to a service steam pipe 35. n

A water gage connection 36 taps into the steam and mud drums I4-I9 and with it is combined a means to automatically control feed water.

` This includes a thermally controlled, pneumatic valve device 40, such as a Controlograph, having a mercurial bulb 4I at the normal water level, whereby a suitably connected, pneumatic motor 42 will be caused to operate a by-pass valve 43 to by-pass excess water from the boiler feed pipe 44, from pump 45, over to the water tank 46; all as diagrammatically shown in Fig. 1.

Means for automatic -control of fuel burner 33 is provided and includes a steam pipe 41 to a pressure governor 48 controlling a fuel valve 49 to the burner 33. Excess steam pressure acts on the governor 48 and this operates to reduce flow at the valve vfrom the fuel pump 50 and the excess fuel is diverted to by-pass valve 5I for return to a fuel tank 52 supplying the pump. The governor 48 is of automatic type under control of the steam pressure.

The fire box 30 opens without obstruction drectly into the elongate, substantially horizontal compartment of the boiler in which the elongate assembly of substantially vertical water tubes 22--23-24 is disposed between the deck of manifolds 25 and the bed of manifolds I8. Thus the hot gases flow in a generally horizontal path between the deck and the bed to the stack and chamber 4 and the flow is obstructed only by the isolated, upright tubes whose upper ends are subjected to the convected hottest gases and their lower ends to 'the lcooler gases with the result that there is always a high pumping efficiency in the manifolds and a high thermal efficiency in the Water tubes.

The centrifugal force of the rapidly descending cooler water in the foot manifolds I8 causes heavy particles to be thrown on toward the mud drum I9 as the water suddenly whirls into the lower or intake ends of the water tubes.

The super-heating coils 3I-32 are embedded in and thinly overlaid by a facing of heat refractive material 54 whereby one protects the other from the destructive heat and at the same time the steam is super-heated.

What is claimed is :l

1. In a steam boiler, beds of vertically spaced sets of manifolds which are connected in Vertical pairs each by a respective central row of spaced water tubes, and laterally out-set rows of tubes arranged along opposite sides of and connecting the manifolds of a relative pair at locations intermediate the center row of tubes thereof; the out-set rows of each pair of manifolds interracking laterally with out-set rows of tubes of the next laterally adjacent pairs of manifolds.

2. A steam generator having a closed cycle apparatus including an inclined deck of header manifolds with a common steam drum, an inclined bed of water manifolds with a common mud drum, the deck and the bed being in vertically spaced relation to form an elongate horizon tal, gas passageway parallel to the axes of the manifolds, and a stand `of upright water tubes in rows connecting relative manifolds of the deck and of the bed; certain rows of tubes of given manifolds being inter-racked in Vertical position along the passageway with tubes of laterally adjacent manifolds.

3. In a steam generator, a steam drum, a mud drum, a system of upstanding down-comers arranged along and leading from :the bottom of the steam drum, and means connecting the steam drum to the mud drum and including Water tubes, and including a bed of inclined, elongate manifolds to which the down-comers are directly connected; the mud drum being diagonally opposite to the steam drum, the down-comers being curved in `one plane, in their length and joined to both the steam drum and their manifolds in staggered relation.

4. In a steam generator, a steam drum, a mud drum, a system of upstanding down-comers arranged along and leading from the bottom, of the steam drum, and means connecting the steam drum to the mud drum and including Water tubes, and including a bed of inclined, elongate manifolds to which the down-comers are directly connected; the mud drum being diagonally opposite 'to the steam drum, the down-comers being in curved, lengthwise medi'ally crossing relation in the system along the steam drum so that their upper and their lower ends are staggered.

CHADWELL OC'ONNOR..

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