US1661900A - Steam-power installation - Google Patents

Description

March 6, 1928.

' J.'MccALLUM ET AL STEAM POWER INSTALLATION Filed Feb. 5. 1927 Fig.1;

Patented Mar. 6, 1928. 7

UNITED STATES PATENT OFFICE.

JOHN MGCALLUM, OF GLASGOW, AND HARRY PERGIVAL HARVEY ANDERSON, OF LANARKSHIRE, SCOTLAND.

STEAM-POWER INSTALLATION.

Application filed February 3, 1927, Serial No. 165,706, and in Great Britain February 1, 1926.

This invention relates to steam power iustallations of the type set forth inthe prior specification No. 97,472 filed 25th March, 1926, and its object is to improve the construction and the efliciency thereof.

According to the present invention, the steam power installation comprises, in combination, a steam generator, a steam power unit, means whereby the exhaust steam from the said unit is subjected simultaneously to positive heat abstraction and to the compressive effect of fresh quantities of further exhaust steam so as to be partially condensed to form a mixture of steam and water, and pumping means whereby the said mixture is passed into the water space of the steam generator, the said pumping means having a pump barrel (or each pump barrel) constituted by a valve structure, comprising automatic suction and delivery valves normally held closed by resilient means, the plunger coming into contact with the valve structure at or near the end of each outward stroke so as to force open the delivery valve and completely expel the fluid drawn into the said barrel through the suction valve at the preceding inward stroke.

According to a further feature of the invention, we provide a steam power installation in which the exhaust steam from the steam power unit of the installation passes into a chamber or chambers communicating,

by means of tubes acted on by cooling water,

with a second chamber or chambers having or each having a reduced outlet, the exhaust steam being thereby partially condensed to form a mixture of steam and water, and the water in the mixture entraining the steam therein as it issues through the said outlet and passes to pumping means, where-' by the mixture is returned to the water space of a steam generator. I

The means to partially condense the steam preferably comprises two sets of U tubes, through one of which sets the exhaust steam is drawn, and through the other of which cool air can be passed, the arrangement being such that about the two sets of U tubes cooling water can be constantly circulated.

The mixture of steam and water resulting from the partial condensation of the exhaust steam may be passed to the steam generator either directly or by way of an auxiliary heater. The said heater comprises a number of manifolds connected in series with one another by tubular. members exposed to the furnace gases of the steam gen orator, the mixture of steam and water aforesaid beingled into the manifold at one end of the series and beingwithdrawn from the manifold attheother end.

' Preferably the air passed through the means. to partially condense the steam is afterwards forced by a fan of known design into the combustion space of the steam generator.

In order that the invention may be fully understood, reference will now be made to the annexed drawing which shows, by way of example, one embodiment thereof;

On the drawing,

Fig. 1 is a diagrammatic (partly section- I .verted U tubes 7 mounted on a circular tube plate 8,. This plate rests on a base 10 which is divided diametrically into two chambers 6 and 11 byv a partition 12. The tubes 7 are arranged in the plate 8 so as to bridge the partition 12 and form the normal means of communication between the chambers 6 and 11. By this devicethe exhaust steam entering thechamber 6 is compelled to pass through the U tubes .7 before being allowed to escape from the other chamber'll by the reduced outlet-11 thereof. The tubes 7 are enclosed by a metal casing 14 through which cooling water is constantly circulated by means of inlet and outlet pipe connections 15 and 16 respectively.

The mixture ofsteam and water formed in the cooling apparatus is withdrawn throngs a pipe 13 by means of pumping elements 18 and 19of the plunger type, either or both of which may be put in operation.

For the sake of clearness, reference will be made to the pumpingielement 18 which is shown in section. The element 18 comprises a plunger 20, and the lower end of the corresponding pump barrel is formed by concentric suction anddelivery valves 21 and 22 respectively. p The barrel of the pumping and delivery valve element 18 is mounted on a casing 23 having an upper chamber 2&- and a 'loWer chamber 2:") communicating with each other through the suction valve 21, the said pump barrel, ()n the delivery valve 22, a bevelled seating is provided for the suction valve :21 as shown, anda larger seating of the same kind is torniedon the adjacent annular edge of the pump barrel for the delivery"valve "lhesaid delivery valve is slidahly mounted in a gland 26 in the casing 523, and a compressed spring 22* is provided between the delivery valve 22 and the said gland 526 for the purpose of holding the sa d delivery valve firmly against its seating on the end of the pump barrel. The suction valve 21 is slida-bly carried inside thedelivery valve 22 and held against its respective seating by a coiled tension spring 21; During the upward stroke of the pump plunger 2 ,the suction valve 21 is drawn upwards against the pressure of its tension spring" 21 so as to admit the mixture of steam and water to thepump barrel. Throughout th s stroke the delivery valve 22 is held against'its seating by its con'ipressed spring 22. On the downward stroke of the plunger 20, the delivery valve 22 isforced oil its seating against the pressure of the compressed spring 22 and the aforesaid mixture is forced out of the pump barrel through the delivery valve 22, the suction valve 21 being held closed by its tension spring 21. i

The stroke of the plunger 20 is such that slightly before the end of the outward stroke, the end of the plunger comes into contact with the plane or flush upper surface of the valve structure constituted by the concentric suction and delivery valves 21 and 22, thereby completely expelling all the mixture of steam and water, drawn into the pump barrel at the preceding stroke; The valve structure aforesaid, under the action ot-tlie spring 22, follows up the plunger 20 until the structure is brought to rest by contact of the delivery valve22 with its bevelled seating on the pump barrel. I

i From the delivery chamber 24 of the easing 23 the mixture of steam and water passes through the valve 27 and pipe 28 to a feed water heater comprising a pair of manifolds Q9 and 30 carried by a plate 31 forming part of the back wall of'the steam generator furnace 32. The manifold 29'constitutes the supply chamber of the heater and the manifold 30 the delivery chamber, and the two manifolds are connectedtogether by a series of tubes 33. Additional support is iven to thetubes 33 by a bridge 3-1 'exten ingbetweenthe tubes and'the lower drum 35 of the steam generator. In order that the feed wator lieate1"niay-be readily inspectedor repaired, tliecovers 36', 3? of the manifolds 29, 3t) aromatic removable.

The mixture of steam and water passes from theananit'old 30 of the feed water heater by way of'a pipe #58 which connuunieates through a valve 3.) with the water space of the upper drum 1 of the steam generator.

'lhis-completes the cycle of the working iluid. .l'hroughout the drawing this cycle isshown by arrows w.

In place of the heater specified above, any known econoiiiizer may be employed, To enable the exhaust steam or a portion thereof to flow directly to the pumping elements 18 and 19 without passing through the inverted U tubes 7, a lay-pass ll) controlled by a screw down valve 41 is provided.

The apparatus for partially condensing the exhaust steam serves as a preheatcr for air for combustion purposes in the steam generator furnace 1t will be observed that the casing 14 ot' the aforesaid apparatus is. surrounded by a jacket -12 which oi wood or like material, the said jacket; being arranged so as to provide an air space 43. The said air space open at its lower end at and, at its upper end, communicates with an air chamber l i formed by a cover to which encloses the ends of the U tubes 46, which latter are similar in construction to the cooling water U tubes 7 but. oppositely arranged. lViththis arrangement. air is drawn in at the open end 50 oi the jacket -12 and by a partition -l-T is caused to pass through the U tubes it; before esea iing t'ronr the jacket. by an outlet pipe 48 connected to a suction and delivery fan 49. The air in its passage through the U tubes 46 is somewhat raised in tempo 'ature by the transfer ol heat from the cooling water in the casing l-l. From the fan 49 the heated air is discharged into the furnace 32 of the steam generator.

In order that the rate of heat abstraction may be regulated in accordance withthe variations of'the exhaust steam pressure, the flow of cooling water through the pipe 15 is regulatedhy means preferably compris ing a control valve provided with adiaphragni 51 which is located in a valve chainher connected by a pilot tube with the exhaust steam pipe 5 of the engine 4 so that the" valve will" be controlled automatically by the action of thediaphragm under" the 'arying pressures of theexhaust steam.

The cooling water is'circulated by'acentrifugal pump (not shown) of known design the said pump discharging the cooling water through the pipe 16 controlled by a relief valve (not shown).

Moreover, the cooling water, if fresh and otherwisesuitable; may be used for the boiler feed. i

The'whole installation is compact and maybe arranged in conjunction with any well known type of steam generator;

Having now "fully described our invenill) tion, what We claim and desire to secure by Letters Patent is 1. A steam power installation comprising a steam generator, a steam power unit, means for subjecting the exhaust steam simultaneously to positive heat abstraction and to the compressive effect of fresh quantities of further exhaust steam, the aforesaid steam being thereby partially condensed to form a mixture of steam and water, said means comprising a chamber into which exhaust steam from the steam power unit passes, a set of U tubes, a second chamber communicating with the first I chamber by means of the said set of U tubes,

a second set of U tubes, means for circulating cooling water around said sets of U tubes, means whereby cool air is drawn through said second set of U tubes and forced into the combustion space of said steam generator, and a reduced outlet for said second chamber, and pumping apparatus for passing the said mixture into the water space of said steam generator.

2. A steam power installation comprising asteam power unit, a steam generator, means for subjecting the exhaust steam from said power unit simultaneously to positive heat abstraction and to the compressive effect of fresh quantities of further exhaust steam, the aforesaid steam being thereby partially condensed to form a mixture of steam and water, said means comprising a chamber into which exhaust steam from the steam power unit passes, a set of U-tubes, a second chamber communicating with the first chamber by meansof the said set of U-tubes, a second set of U-tubes,

mixture into the water space of said steam generator, and an auxiliary heater for said mixture comprising a number of boxes and tubular members connecting said boxes in series with one another. c y

3. A steam power installation comprising a steam generator, a steam power unit, means for subjecting the exhaust steam simultaneously to positive heat abstraction and to the compressive efiect of fresh quantities of further exhaust steam, the aforesaid steam being thereby partially condensed to form a mixture of steam and water, said means comprising a chamber into which exhaust steam from the steam power unit passes, a set of U-tubes, a second chamber communicating with the first chamber by means of the said set of U-tubes, a second set of U-tubes, means whereby cool air is drawn through said second set of U-tubes and forced into the combustion space of said steam generator, an auxiliary heater for said mixture comprising a pairof troughs,

a plate carryingsaid troughs and adapted for passing the said mixture into the water.

space of said steam generator.

In testimony whereof we aflix our signatures.

JOHN McCALLUM.

HARRY PERCIVAL HARVEY ANDERSON.

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