US1737213A - Apparatus for automatically controlling the feed water of steam boilers - Google Patents

Description

APPARATUSFOR AUTOMATICALLY CONTROLLING THE REED WATER OF STEAM BOILERS Filgd March 17, 1927 o O W1 2 16? i m 28 o /\fl 4 1WD 2.9 A .9 Z4 2 9 Z5 12 o :Z: 0 j //YVE NT E.

patented Nov. 26, 1929 eater @FE LOUIS MAURICE BERNON, OF LONDON, ENG-LAND, ASSIGNOB 0F ONE-HALF TO ROBERT JAMES WALKER, OF LEICESTER, ENGLAND APPARATUS FOR AUTOMATICALLY CONTROLLING TEE FEED V/"ATER OF STEAM BOILERS iApplication filed March 17, 1927, Serial No. 176,160, and in. Great Britain April 13, 1926.

This invention relates to apparatus for automatically controlling the flow of fluids under pressure, such as boiler feed-water, and has for its essential feat-urea valve for this purpose coupled to an operating element wherein the power for moving the latter (and thus indirectly to actuate the valve) is derived from the pressure of the incoming fluid. The control of this operating element is under the influence of the level in the vessel being fed.

In the present invention the controlling element is a double-headed piston between and past the heads of which the incoming fluid can flow, the piston moving to operate the valve according as a pair of openings in its cylinder vary in area, the variation being dependent upon the condition of the vessel being fed.

In more particular terms defining an embodiment, the said invention comprises a main fluid valve operating in conjunction with a piston in a chamber always in communication with the pressure fluid on the inlet side of the said fluid valve. Said piston is double-headed and unpacked so as to be a free fit in the chamber and the fluid pressure acts between the heads to set up normally a balance and condition of rest, this condition being varied as and when the area of'opcning at a pair of outlets to the piston chamber (one at the other side of each piston head) becomes unequal and leakage past the piston heads unbalanced, the piston then moving to actuate the main fluid valve through suitable linkage. Means are employed, influenced by the level in theboiler or the like, to control automatically the said areas of opening, and thus indirectly to govern the movement of the main fluid valve.

' The invention will be better understood by reference to the following description of embodiments more in detail which are illus trated by the accompanying drawings, wherein Figure 1 shows, in vertical section, a main fluid valve with its actuating means, coupled up to a control chamber influenced by boiler liquid level.

Figure 2 is a vertical section of a modified form of control chamber. 7

Referring to'the drawings, the apparatus comprises a valve-controlled, vertically or otherwise disposed, chamber 1 which is connected up to a pump which forces water into said chamber under pressure greater than the steam pressure of the boiler. For this member, whichis the main fluid valve, a doublebeat valve 2 is shown. 7 I

This water chamber 1 is formed with a horizontal branch pipe 3 carryinga vertically disposed cylinder 4 in which is slidably mounted a plunger which is constituted by two opposite opposed unpacked pistons 5, of

equal area, carried by a rod 6 common to both pistons. Saidrod 6 is connected to the one end of apivot-ally mounted lever 7 located in the branch pipe aforesaid, theother end of said lever being connected to the vertically disposed spindle S of the valve 2 aforesaid, which valve controls the flow of feed-water from said chamber 1 tothe boiler. The direction of flow is indicatedby arrows.

Arranged elzteriorly of the boiler is a vertically disposed vessel 9, which maybe termed a control chamber, the upper part of which constitutes a steam chamber, and the lower part a well to which water from the boiler is supplied by way of an opening 10, whilst the steam chamber is connected by pipe to the steam space of the boiler, through openin 11, so that the level of the water in the well corresponds with the level of the water in the boiler.

' In the well aforesaid there is provided a bucket or other float 12 which (as in Figure 1) is connected to the horizontally disposed. arm 13 of a counterbalanced or weighted (preferably adjustably) bell-crank lever 14: which is pivotally-mounted above said bucket or other float 12, whilst to the vertically disposed arm of said bell-crank lever there is pivotallyconnected the one end of a link 15 which, by its other end, is pivotally connected to the lowerend of the long arm 16 of a lever with unequal arms, the other arm being designated 17. V 1

Theupper end of the short arm 17, which is pivotally mounted in the upper part of the 7 19 is, by a pipe '22, connected to the space 23 steam chamber aforesaid, is operably con-' above the upper piston 5 of the plunger,

Whilst the other port controlled by valve below the lower piston 5 of said plunger.

Assuming the water in the wellto be at high water level, and that the valve 18 controlling the port connected with, the space 21 above the upper piston 5 is fully open, and thevalve 19, of the port connectedtbspace 23 below thel'ower 'iston 5 of the plunger: is closed"( notnece's'sarlly tightly on'its seating) then thepressure on the outsides respectively isiton's 5; (due tole'ak agepastth'e pistons '0; the incoming fiuid) will become unbalanced; the resistai e injcha'mber: 21 becomes eased and consequently the'plunger a'ssumes its upstroke position," shutting main valve 2.

V Onthe water l evel ih'theboi'lcr falling, and

consequently the level ofthew'ater in the well 9 aforesaid, the bucket or other float" 12 sinks jand'cause's thejbell-crank lever 14: to turn; on its I pivot, and through the link I 15 connectlng said bell-crank leverjtfo the unequal arm lever 16 aforesaid to rock said lever on its fulcrum. 1 Thisresults in thevalve18 closing more or less, whils't, at the same time, "the valve 19 is -fully' opened, with the result'that the unequal areas of opening to'the chambers 21 and 23 are reverseda'nd consequently the pressure of the watero'n the pistons 5, 5' aforesaid'ca'uses the plunger to move down. In

7 practice it has been'ascertained that if the openi gs to the chambers 21 and 23 are of equal area, then a condition ofba'lance and rest is (set up by the pressure between the heads 5, but if the areas ofexitfo'r opening are varied, then the pressure frorn'the chamher 1 will move the plunger 5', 5 towards the openings of larger area as the .pressureleakage past the'piston atthat' s'i'de hasgreater freedom of escape.

This downward movement of the plunger 5, 5 through the intermediary of the lever 7 connected to said plunger and to the spindle 8 of the valve QIOf'tliewater'chamberl, lifts 4 'said valve 2 from off its seat,tliereby allowing water to flow from said eh amber into the boiler under the actionjof the pump aforesaid.

Asthe'water in the boiler rises to high le'v'el again, soi'doesthe' bucket or'other, use; 12 ri rresp d i ly,endj l t e ljlc ra'nk lever andune'qual, arm lever aforesaid operates the'val've's '18, 19 or the "cha'mbr'in reverse manner, thus gradually closing the fully opened port "and fully opening the closed port.

This results in that the plunger 5, 5 moves upwardly again, because the pressure of the incoming fluid past plunger 5 into the upper piston chamber 21 is eased by leaking back past its "control valve 18 to the steam chamber aforesaid, and this upward'inovement of the plunger through the lever connected etoand to the spi d of t e Water yal i closes down said. valve 2 accordingly, thereby gradually reducing the flow of water 'therethroughto the. boiler til'l su'chftime 'as'the water level in the boiler is restored to normal of the respective leakages past 'the'he a'ds '5 5-, in the chambers 21 and23, a I Y 7 Any suitable mode of varying the area of the openings to the chamber's 21ai d23 un der the influence of the boiler liquidl'evel ey By war i p a iiodified ferin price-semi "chamber 9, with its steam waterinlets 11 and 10, and-float 12 Figure 2. f In this form,the branked arm 24 is fiinedl at-taehedae the mouth of the bucket 12; 1 he central "rod "25 is'a fixture, and the bucket in risihg, and falling rocks about the link 27. V r

By this device the bucket is guided and heldfirlnly in vertical position, whilst oscillati'on thereof is obviated.

pivot 26 by the connecting 4 v The bucketsmovement "reeks a toaster "balanced arm '28 about a pivot 29, afnd'so controls the valves 181 and191. The latter are connected to the chambers 21 and 23and operate as in the previouslydescribed example. Thesaid valves 181 and 191 are capable of adjustment to and from'th'eir seatings'by "means of the adjustment devices 182 and 192 including a valve, an operating element cou- PM t s d valve, a 1 wherein the. p w

istons 5, 5, it is pointed out that'means may 7 .i'Q qving he p r tin s em s rili from pressure of the incomlng fluid comprising a double-headed p ston constituting the foperatingfelenient, betweenand past'the heads f w hemeeming fluid must now,

"the piston moving tooperat'e the valve according to the flow of liquid tlirough the openings in its cylinder, the variations depending upon the condition of the vessel being fed.

2. In apparatus for automatically controlling the flow of fluid under pressure to a vessel, a main fluid valve operated by an unpacked freely fitting double-headed piston reciprocating in a cylinder, a passage from the cylinder to the inlet side of the valve, said passage communicating between the two piston heads, openings in the cylinder ends, and means automatically controllable b the fluid level in the vessel to regulate the ow of liquid through said openings and thus control movement of the piston by the incoming fluid pressure, which leaks past the heads thereof, substantially as described.

3. Apparatus for automatically controlling the supply of boiler feed water comprising in combination a control chamber with a pair of valve-controlled openings, steam and water inlets to said chamber whereby a float rises and falls with the boiler water level, means whereby the float operates the valvecontrolled openings, a main fluid valve governing the supply of boiler feed water, and a double-headed piston capable of operating the main valve, said piston reciprocating in a cylinder having an opening at each end communicating respectively with the aforesaid two valve-controlled openings of the control chamber, substantially as described.

a. In apparatus for automatically controlling the flow of fluids under pressure to a vessel, a main fluid valve and coupled operating element including a double-headed piston reciprocating in a cylinder, a passage from the cylinder to the inlet side of the valve, said passage communicating between the two piston heads, openings in the cylinder ends, and means (automatically controllable by the level of liquid in the vessel) to regulate the flow of liquid through said openings and thus control movement of the piston by the incoming fluid pressure.

5. In an apparatus including a boiler and means for automatically controlling the flow of fluid under pressure thereto, a main fluid valve operating in conjunction with a piston in a chamber always in communication with the pressure fluid on the inlet side of the said fluid valve, the piston in said chamber being double-headed and the fluid pressure acting between said heads to set up normally a balance and condition of rest, this condition being varied as the flow of liquid through a pair of outlets to the piston chamber (one at the outside of each piston head) becomes unequal, the double-headed piston then moving to actuate the main fluid valve through suitable linkage, and means influenced by the level of liquid in the boiler automatically controlling said areas of opening.

6. Apparatus for automatically controlling the supply of boiler feed-water, comprising in combination a control chamber with a pair of valve-controlled openings, steam and water inlets to said chamber whereby a float rises and falls with the boiler water level, means whereby the float operates the valvecontrolled openings, a main fluid valve gov- LOUIS MAURICE BERNON.

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