US2365081A - Feed water regulating apparatus for boilers - Google Patents

Description

Dec. 12, 1944. w, HUNTER 2,365,081

FEED WATER REGULATING APPARATUS FOR BOILERS Filed April 14, 1942 2 Sheets-Sheet l 1a INVENTOR WILL/AM L. HUNTER 5y ATTORN EY Dec. 12, 1944. w HUNTER FEED WATER REGULATING APPARATUS FOR BOILERS Filed April 14, 1942 2 Sheets-Sheet 2 INVENTOR W/LL/AM L. HU/V T117? 5) 0. Min

ATTQR N EY Patented Dec. 12, 1944 -William .L. -Hunter Erie, Pa.. .ass ignor to'Northern'j Equipment jlGompany, 'Erie, Pa., 2, corporation df'Pennsylvania .ApplicationAprilaM, 1942, S,er-ialo.--,438-,-960

'3 "Claims. "(CL 122-4511) This invention relates 'to feed water regulating apparatus for boilers, and more particularly to apparatus of this typewhich has distinct advantages when employed -on marine boilers 'althoughnot limited 'to such use.

Asis well HI'IdGI-StOOdyitiS desirable'to automatically regulate *the' feed-water supply toboilers and maintain the boiler water level within pie-determined limits. This'has commonly been effected in -stationary=boilersby havingv a tube or the like in communication with the steam and water space of th'e'boiler "whereby the water level in i the tube will correspond to the water level in the boiler' ancl regulatethe'feed 'water valve in accordance with tube-water level. However, such apparatus is not satisfactory for marine "boilers since the tube water" levelis' materially disturbed by the roll of theship resulting inrapid-and highly undesirable fluctuations in-the amount of feed--water being 'fed to the" boiler.

-I am aware that it has previously been proposed to compensate for, ship roll by employing two tubesor the'like fixed to each side of'the boiler and laterally outward thereof whereby as theboiler is "tilted due to ship roll "a drop 'in waterlevel in one, tube will be accompaniedbyia corresponding-rise in' the *othertu'be. "Both'tubes are adapted to'infiuence the feed watersupply sothata compensating'e'ffect is achieved with a relatively small angular ship roll. However, since each'tubeis necessarily disposed a'substam tial distance from the' vertical center line of the boiler considerable fluctuation in tube water level results "and with i considerable angular roll 'the tubes may be-emptied or completelyfilled. Practical considerations limit the height or extent of the tubes and it is apparentthat'if the water level is exended beyond the tube limits that the control or the feed-water will be'erratic.

Itis a primary object'ofmy inventionto provide improved *feed water "regulating apparatus for boilers.

Another object or :my invention is .to provide feed water regulating apparatus forlboilers and which is particularly adapted ,to,marineboilers whereb anjaccurate control oftheffeed water will be maintained responsive to the steam demands despite considerable angularlroll-of the ship.

Anothenobjectpf .myinvention is to prov icle improved .feed water ;,regulatin g apparatus for boilers which can'be easily installed .on a conventional boiler and which risereadily adjustable.

.othen objects zof=.th'e invention "will be increasinglyapparent from .a consideration of the ,following.description:and;drawings.

According to "the invention, :a generally V shaped .tube .iadapted rto expand land aoontract under "thermal :change; is l mounted-externally .of thedrum headrof saaboilerlwith the apexzpf the tube lbeing 1 disposed substantiallypon qtheuvertical center line i of the :boiler ;and .the ;tube arms lextending at substantially .equal angles ;at each side; of .the center; line. 'lThE 1 apex .:of :the'ztubea is fixed and ends ,of: the armsare: free'to .move: under thermal change. Each v.of ithe arm ends .:is connected to aseparate lrock .levers which are pivoted laterally of -.ea.c.h arm. .One of ,theqrock levers is adapted to operate-the feed iwaterivalve in accordance with llever :movement and 13118 levers are inter-connected by dink 'means whereby expansion of :one :arm a given amount -.and contraction of L the :.other .arm .an :equal :amount will effect. no achange linuthe position of the .feed watertvalve. 'The apex of .theztuherand the arm ends are .iconnected to the boiler whereby'in a stationary. boiler the 'lengthlof each. arm will at all times bet-substantially thelsame, and will zbe determined abyl the boiler water: level.

kWhenzemployed on :a @marine boilerene arm will zexpandrinaccordance "with the amount the boiler is tilted from a normal position i and 'the other'willicontract buti the-icomposite action will not materially :effect the position of the 'feed waterx-valve. :Due'to the normal water levelin each i arm being only a short distance laterally fromithe .verti'calicenter line of the boiler'the water level -..only :fluctuates through relatively smalli distances: despite consider-ableangular roll of theshipand :well within the tube limits so that .an accurate control of the feed "water is Referring now *to the drawings, and'particularly Figs. l-and' z I have indicated aboiler drum at 1 0 and-the drum headat H. -Thefeed water supply line I2 connects with afeed'water valve 1-3 and the-valve is =connectedtoa'line I4 communicating with thelower portion of the boiler drum. The particular type of valve used constitutes no essential part of the present invention but I preferably employ a valve of the piston type wherein a rotatable lever shaft I6 is disposed eccentrically of the line of piston movement and through suitable internal link means the piston lift and flow of feed water is controlled by the g will continuously urge lever IS in a direction to open the valve.

The regulating apparatus will now be de- A scribed. A pair of brackets 23 secured to line H support a generally triangular shaped frame 24. Frame 24 may comprise a pair of spaced members 26 of channel cross-section and preferably formed of iron or a material unaffected by thermal change. However, since the frame 24 is installed in a zone of relatively constant temperature it may be made of any suitable material as its dimensions remain practically constant. Mounted between frame members 26 is a thermostatic tube 21 of inverted V form, the apex of tube 21 being positioned in frame 24 by a Y element 28 supported by a spacing plate 3| disposed between members 26 and adjusting nuts 30. The

arms of tube 21, indicated at 32 and 33 are seal-- ingly secured to element 28 and are inclined at substantially equal angles. Arms 32 and 33 are of substantially equal length and frame 24 is mounted to dispose the apex of tube 21 at the vertical center line of the boiler drum and the horizontal center line of the arms slightly below the normal water level of the boiler.

A rock lever 34 is mounted between frame members 26 to rotate about an axis 36 and is pivotally connected to tube arm 33 as indicated at 31 whereby lever 34 will be rocked as arm 33 contracts and expands, A second rock lever 38 mounted in a similar manner is adapted to be rocked by thermal change in arm 32 and it will be noted that when both arms expand the rock levers are moved towards'each other and when both arms contract the rock levers are moved away from each other. An L shaped lever 39 is pivotally connected to the upper end of rock lever 34 as shown at 4|. A pair of link arms 42 are pivotally connected to the upper end of rock arm 38 and at theopposite ends are adjustably and pivotally connected to lever 39. A strut 43 is adjustably and pivotally connected to a horizontally extending part of lever 39 and at the lower end is 1 pivoted to the outer end of arm l8 of lever ll. Strut 43 is provided with tension relief means 44.

The operation of the apparatus so far described will now be explained. Assuming the apparatus to be used on a stationary boiler or a marine boiler disposed parallel to the fore and aft center line of the ship and that the ship is riding at an even keel, the thermostatic tube 21 is connected at the apex with the steam space of the boiler through a line 46 sealed to element 28 and the lower ends of arms 32 and 33 are connected with the water space of the boiler through a conduit 41 so that the water level in each arm will be the same andwill correspond with the boiler water level. Upon a decrease in boiler water level there will be a. similar decrease in each arm and an increase in the amount of steam in each arm causing both arms to expand an equal amount where-.

upon rock arm 38 will be rotated in a clockwise direction and move lever 39 in a clockwise direction. Rock lever 34 will move in a counter-clockwise direction and further move lever 39 in a clockwise direction. Thus, strut 43 is moved downwardly and this movement is aided by tension spring 2| causing lever I1 and shaft IE to open the valve. causes a reverse action but in each instance the action of the arms of the thermostatic tube on lever 39 is cumulative rather than opposed.

. It will be noted that tension spring 2| is the source of power for opening the feed water valve when the water level falls. Further, spring 2| maintains the whole system in tension and thereby takes up the slack at the pin-connected points and keeps adjusting nuts 3|] tight against the plate 3|. Of course, slack in the system could be prevented by disposing adjustable support means beneath Y element 28 and Weight or spring load the thermostatic tube 21 at its apex t maintain the tube arms under compression.

The relative effect of the rock arms on lever 39 may be altered by connecting link arms 42 at different holes 40 and the amount of valve movement fora given movement of lever 39 may be altered by connecting strut 43 at different holes 45.

If the apparatus is used on a marine boiler and the ship is rolling the Water level in each arm 32 and 33 will alternately rise and fall since frame 24 is fixed to and will move with the boiler. As the boiler is tilted in a clockwise direction arm 32 will be raised and the water level therein will be lowered causing the arm to expand and resultantly lever 39 will tend to move in a clockwise direction. However, arm 33 will be lowered causing the water level therein to increase thereby contracting the arm and tending to move lever 39 in a counter-clockwise direction with the net result that lever 39 is not appreciably effected by ship roll and an accurate control of the feed water is maintained. If the normal boiler water level is indicated by line L it will be noted that the distance D from the vertical center line of the drum to the water level in the thermostatic tube arms is relatively small and that if the angular roll of the boiler is considerable as indicated by the line L that the fluctuation in water level in the arms is relatively small and well within limits which would completely empty or fill either arm.

Although I have shown and described a preferred embodiment of my invention I contemplate that numerous and extensive departures may be made therefrom without departing from the spirit of my invention and the scope of the appended claims.

The invention is hereby claimed as follows:

1. Feed water regulating apparatus for boilers comprising a boiler drum, a generally V shaped thermostatic tube having its apex fixed to the drum head substantially at the vertical center line thereof and its arms inclined at substantially equal angles to said center line, the arms being substantially equal length and the arm ends remote from the tube apex being freely movable under thermal change, the tube being connected to the steam space and water space of the boiler at the apex and arm ends whereby the arms will expand and contract in accordance with the relative amount of steam and water therein, the tube apex connection forming a fixed common communicating means for both arms with the boiler a feed water valve, means for actuating the valve,

An increase in boiler water level and link means connecting each of said arm ends with the actuating means whereby the valve will be actuated in correspondence with the composite movement of both arm ends under thermal change.-

2. The feed water regulating apparatus as described in claim 1 and wherein the link means comprises a pair of rock levers each movable by a different arm, and a third lever operatively connected to the valve and pivotally connected to each of said rock levers at spaced points.

3. Feed water regulating apparatus for boilers comprising a boiler drum, a, triangular frame of material relatively insensitive to thermal change having its apex at the vertical center line of the drum and arms extending at, substantially equal angles to said center line, a generally V shaped thermostatic tube having its apex fixed to the frame apex and its arms nested in the frame arms,

a pair of rock levers pivoted on the frame and each being movable by a diiferent tube arm under thermal change, the tube. being connected at the apex and arm ends to the steam and Water space of the boiler whereby the water level in each arm will correspond to boiler water level, a feed water valve, 2. third lever operatively connected to the valve and pivotally connected to the rock levers at spaced points whereby the third lever may be independently moved by either rock lever, and the levers being arranged so that when the boiler is in normal position the effect of the rock levers upon the third lever is cumulative upon a change in boiler water level and when the boiler is suddenly tilted the effect of the rock levers upon the third lever is opposite.

WM. L. HUNTER.

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