US507910A - johnstone - Google Patents

Description

3 SheetsSheet 1.

(No Model.)

L. JOHNSTONE. AUTOMATIG FEEDING DEVICE.

Patented Oct. 3:1.I .1893,

//VVNTOR.

IV/TNL'SSE-S.

(No Model.) 3 Sheets-Sheet 2.

L. JOHNSTONE. AUTQMATIGEEEDINGIDEVIGB.

No. 507,910. Patented 00:. 31, 1893.

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I z I /NVNTOR. WW 4% UNITED STATES PATENT OFFICE.

LEWIS J OHNSTO'NE, OF EDINBURGH, SCOTLAND.

AUTOMATIC FEEDING DEVICE.

SPECIFICATION forming part of Letters Patent No. 507,910, dated October 31, 1893. Application filed May 22, 1893. Serial No. 5,029. (No model.) Patented in EnglandAugust 20, 1892, No. 15,062.

To all whom it may concern.-

Be it known that I, LEWIS JOHNSTONE, engineer and analytical chemist, asubject of the Queen of Great Britain, residing at 10 St. Andrews Square, Edinburgh, Scotland, have invented an Improved Automatic Feeding Device, (for which I have obtained Letters Pat-- entin Great Britain, No. 15,062, dated August 20, 1892,) of which the following is a specification.

My invention relates to an improved apparatus for returning into the boiler the water of condensation from coils, steam jackets, heating pipes, steam drying cylinders, &c., or for forcing ordinary feed water into the boiler, or other similar purposes. my present invention may be easily understood and readily carried into practice I will proceed to describe same with reference to the drawings hereunto annexed.

Figure l is a general view of an apparatus for returning water of condensation into the steam generator from a point below the wafor level in such steam boiler. Fig. 2 is a similar view of my apparatus for effecting the same purpose from a point above the water level in the generator. Fig. 3 is a vertical (longitudinal) sectional view on line 1-1 Fig.4 of the special valve apparatus and its connections according to my present invention. Fig. 4 is a sectional plan on line 22 Fig. 3. Figs. 5, 6, 7, and 8 illustratea slightly modified construction of the special valveas hereinafter explained.

Similar letters of reference indicate corresponding parts throughout.

A is the steam boiler or steam generator of any usual or suitable construction.

13 is the main steam pipeleading to any steam motor, steam jacket coil or drying chamber, or other steam actuated or steam heated device or the like all of which for the sake of brevity I shall hereinafter refer to as the coil.

O is the coil illustrated by way of example.

D is the outlet from the coilleading into E.

E is. the casing containing the special valve apparatusshown in detail in Figs. 3 and 4 and in Figs. 5 to .7.

F is the branch steam pipeleading from And in order thatv I the main steam supply pipe 13 into the easing E.

G is the outlet pipe from the valve casing E-leading to the reservoir H.

H is the lower reservoir (as I term it) in which the water of condensation is accumulated ready to be forced into the reservoir J.

I is a pipe leading from H to J.

J is the upper reservoir (as I term it) from whence the water passes into the generator A.

K is a pipe leading from J into the lower part ('i. (2. below the water level) of generator A.

L is a blow off cock in pipe K.

M is a T-piece or branch pipe leading from D to a third reservoir N.

N is a reservoir where the water of condensation accumulates from the coil 0.

O is a pipe connecting the lower part of reservoir N with the lower part of the reservoir H.

P is a branch pipe leading from the pipe I to the under side of the steam piston valve Q in the casing E.

Referring now to the equilibrium or balance valve apparatus shown in Figs. 3 and 4:Q is a large piston valve acting as a tightly fitting piston or plunger in the cylinder or chamber R which latter may advantageously be formed with a bush or lining S as shown. T'll are apertures in the cylinder R controlled by the valve Q and leading from the cylinder R to the outlet G through the steam passage way U. U is a steam passage way leading from the pipe F cylinder R and apertures T to the outlet pipe G and also to the inlet apertures '1" round the second valve cylinder W. V is a second and smaller piston valve. W is the cylinder of the second valve V also advantageously lined similar to R and also having apertures T (or other communication) with the passage way U. X is the piston rod on the piston Q, and X the piston rod on the piston V, both pivoted to the pivoted lever Y. Z is a fixed support carrying the pivoted leverY which latter therefore has its fulcrum on Z. a is aback pressure valve to prevent any return of water from the boiler A into the pipe K. b is a back pressure valve in the pipe I to prevent pressure from the pipes K and I and chamber J,

coil 0.

passing back in the chamber 11. c is a back pressure valve to prevent pressure from the chamber II or pipe I passing back into the pipe 0.

The automatic operation of the equilibrium or balance valves Q and V is as follows:-The full live steam pressure is constant (when the apparatus is in work) through F onto the top side of piston Q which when forced downward admits same live steam through the conduits T. U. G. H. I. and P to the under side of the piston Q and thus equal steam pressure will exist on both top and bottom of piston Q and so the latter is brought into equilibrium and can then be easily controlled by the second valve V and their respective connections. The valve V is now at its uppermost position andon the top side thereof has applied thereto the pressure coming through D from the The steam valve Q being already inrequilibrium (in its lowermost position)as just-previously explained the least pressure or force exerted onthe top of V (sufficient to overcome friction) will force down V to its lowermost position and through the pivoted lever Y and the respective piston rods X and X will therebymove up the valve Q to its uppermost position while in the case of the valve V as soon as it passes the apertures T steam pressure will be thereby admitted to the upper side of the valve V. With the valve Q thus at its uppermost position and the valve V at its lowermost positionthe full live steam pressure from B and F remains constant on the top of Q while the steam pressure remaining in the parts I, J, K and P is prevented from passing back by means of the back pressure valve b and as this steam pressure dies away in the parts I, J, K and P (by reason of radiation, condensation or by a spe cial exhaust, &c.), the pressure through the pipe P on the under side of the valve Q will decrease and then as soon as the constant pressure on the top of the valve Q is greater than the resistance of the valve V plus the remaining pressure under the valve Q plus friction then the piston Q will be forced down and a fresh charge of live steam suddenly passed through R. T. U. G. H. I. and P and the cycle repeated asbefore. To assist the quick actionof the balance valve so that immediately the valve Q has begun to move down it shall continue its movement 1'a pidlyI may use what I term a dash-pot or regulating device such as illustrated and consisting of a by pass ef in the cylinder W as shown in dotted lines in Fig. 3 acting in conjunction with the valve gear beneath the valve V as shown in Fig. 3 to automatically permitexhaust from beneath valve V at the desired moment; viz: The valve V carries on its under side the extension forming a smaller-plunger g closed at its bottom end It and having openings 2' at its top end and openingsjat its lower part this lower part passing through a gland It so that immediately the apertures j in the side walls of g pass below the closelyfitting part of gland 7c; then the steam beneath valve V is exhausted. The action of this partial equalizing of the valve V is as follows:- Assuming the valve V to be at its lowermost position in the cylinder W it will cover and close the end f of the by-pass and also the aperturesj will lie clear of the gland k and therefore no pressure will now exist below valve V. As soon as the valve Q is forced down and consequently lifts the valve V against the pressure pipe in D.'then the apertnresj are brought inside of gland 7c and consequently closed. At the same moment the endfof the bypass is uncovered by the upward movement of the valve V and therefore pressure above and below valve V will be partially equalized and consequently part of the resistance to valve Q at first oifered by valve V is now suddenly removed and thereby the-valve Q will perform the rest of its travel downward at a greatly increasedspeed. On the return movement that is .when the valve V is moved downward (and thereby lifting the valve Q) the movement of valve V is slow owing to the pressure under valve V coming through the bypass ef but assoon as valve V closes f and exhaustion ispermitted at j then no resistance will remain under valve V and consequently the latter-will perform the rest of its travel at a greatlyaccelerated speed. This arrangement or equivalent will be found of greatutility especially in cases where great variations may existfrom time to timebetween theboiler pressure and the pressure in pipe ,D during the working of the apparatus.

In cases where a great differencenormally exists between the boiler pressure and the pressure in coil 0 and its outlet D-then this difference may be compensated for by weighting the end Y of the lever Y or by altering the relative sizes (areas) of the valves Q and V for instance the latter might be of much larger area than Q-as hereinafter further explained.

The operation of the whole apparatusis as follows:-The water of condensationfrom the coil C-(or other water to be returned or fed to the boiler A) coming through the outlet D (which may or may not be on a decline for this purpose) passes through the T-piece M and accumulates in the reservoir N and pipe 0. As soon as the reservoir II has been emptied of its last charge, steam pressure is equalized in both top and bottom of II by the valve V being forced down (as before described) and thereby whatever steam pressure exists in the pipe .G and reservoir H will pass through the parts U T W and D to M and N. Thus pressure being equalized all through these last named partsthe water accumulated in N will now by gravity descending through 0 past the back pressure valve 0 and fill or partially fill the reservoir II. I would here remark that the parts E. H. J and N and their connections are shown in Figs. 1 and 2 on a much larger scale in pro- IIO portion to the other parts of these Figs. 1 and 2-'this being done for the sake of clearness.

- Figs. 3 and 4 represent the valve apparatus. As soon now as the pressure under valve Q has died away or decreased sufficiently the live steam in branch steam pipe F will force down valve Q (as before explained) and thereby" the apertures T are uncovered by valve Q and a charge of live steam is delivered from F through the parts R. T. U and G to the upper surface of the water in the reservoir H which is thereby suddenly driven -out' of the reservoir H and as it cannot escape back through'the back pressure valve cit is therefore driven past I) through the pipe I to the reservoir J which latter reservoir J is and always must be placed at a height above the water level in the boiler and should be of a capacity somewhatlarger than the reservoir H. Having got the charge of water up to this elevated position (in the reservoir J) much above the water level in the steam generator A it will thus be easily seen and understood that, as such water in the elevated reservoir J will have the full steam pressure from the pipes B and F through the pipe I behind it, the pressure from the boiler at a will be equalized-while the weight of the water in theres ervoir J (that is gravity) will cause the said Water to readily pass through the feed pipe K (past the back pressure valve a) into the boiler A. The live steam supply to the pipe I lasts a sufficient time to do its work and as soon as same is cut off and the pressure in the pipe I begins to decrease then the pressure from the steam generator A will close the back pressure valve or and consequently no water can come back from the said boiler A into the pipe K; and thus as no water from boiler A can come back past a consequently no water column is thereby formed in the pipe K. Meantime While the pressure has been dying away in the pipe I the further accumulation of water in the reservoir N has emptied itself into the reservoir H and live steam being again admitted to the upper part thereof this charge is driven through the parts I. J and K into the boiler-A and'so on-thewhole cycle being automatic and automatically and periodically repeating itself so that very large quantities of water can be by my apparatus steadily returned into the boiler.

It is for the especial purpose of being able I small quantities of return water where very great difference exists between boiler pressure and the coil or feed water and for these and other reasons giving great advantages over apparatus previously designed for similar'purposes.

Referring to the modified construction of valve apparatus shown in Figs. 5, 6, 7 and 8: Fig. 5'is a horizontal'sectionon the line 33 to V).

Fig. 6. Fig. 6 is a vertical section online 4-4 Fig. 5. Fig. 7 is a vertical section on line 55 Fig. 5. Fig. 8 is a cross section on line-6-6 Figs. 6 and 7. The letters D. E. F. G. P. and U respectively designate the same parts as in Figs. 3 and 4.

Referring Qto Figs. 5 to 8: q is the steam valve (corresponding to Q). 1' is cylinder in which q operates (corresponding to R). s is piston rod on g slotted to receive the end of arm t see Fig. 6. tis arm on the axle shaft tt which arm t is connected to s as'shown in Fig. 6 or in any other suitable Way. u is axle shaft mounted with glands or stuffing boxes or in othersuitable steam tight manner in the casin g'E. o is second valve (corresponding '40 is piston rod on v. a: is'arm connected to to similar tot and also keyedor otherwise fixed to shaft u. y is an arm or lever also fixed at right angles on the shaft uby which means a counter balance may be used or a dashpot attached thereto to control the valves as desired. .2 z are oil feed cups to keep the internal working parts of this valve apparatus lubricated It will thus be seen that the valves q and o arexconnected through the shaft to and connecting arms t and so so that when the valve qis forced down the valve'u is thereby forced up and vice versa.

The operation is as followsg-The full steam pressure coming through pipe Fforces down the valve q clear of the passage U whence the steam pressure passes as before through G into H. I. J. and K,'while as soon as equal steam pressure-attains at P the valve q is brought into equilibrium and the pressure at D acting on top of 'u will thereby force down '0 and consequently raise q and thus cut ofi steam from F passing to U While as soon as the top of o clears passage U the steam therein remaining can exhaust back into the 'coil and'at the same time may act on o to accelerate its downward movement.

' The apparatus shown in Figs. 5 to 8 will thus be seen to be very simple in construction and'action and will be found to work Well in cases where the variation between the pressure in F and D is constant or approxi-- mately constant. Where however the pressure in D is liable to great variation it willbe found necessary to adopt and use a compensating arrangement such as illustrated in Fig. 3 or in the alternative a greatly increased length ofrise in pipe I so as to give a greatly increased height to J and consequently'increased fall from J to A'as further explained hereinafter.

The advantage of having the bush or lining S in the cylinders R and W (Figs. 3 and 4:) with small apertures T T therein into passage Uis that split piston rings or packing rings may be used on Q and V, whereas in the arrangement such as shown in Figs. 5 to 8 such packing rings could not be used.

Some lap should be given to the steam valve Q or q and also to theequilibrium' or balance ICC valve V or r so that the one closes before the other opens and to reduceleakage, the.

It will be readily understood that where the coils are on a higher or different level from the water level of the boiler the proper position can be easily found where the above conditions apply. Further the apparatus may be arrangedand mounted at any convenient point (within practical limits) more or less distant from the boiler.

W'eightiu g the steam valve against the live 1 steam may-be adopted andhas several advantagesafor instance as a means of regulating the stroke of the valves and to retard the live steam from acting again too quickly.

The amount of weight required tobalance thebalance valve of the coil outlet sidecan naturally be much reduced bymakingsaid valve of smaller diameter, and this is ofiade size of the outlet valve may be increased beyond that of the steam valve so as to be more sensitive to thisvery low pressure. The advantageof thus; making the valve more 101 less self balancing as againstthe amount of dead weight required is readily seen bya simple example of calculation.

If the valves are of equal area say one inch, the steam valve being in equilibrium, the boiler pressure sixty pounds and the outlet from coil thirty pounds periinchthe weighting necessary will be thirty pounds or its equivalent by leverage. If however the valve bemade partially self balancing say the area of pressure on the under side be made half that on the upper the amount of weighting will be one half of the former case, 71. e., fifteen poundsor its equivalent by leverage. Further if the area of this valvebe reduced to say half inch area the weighting without the self balancing would be fifteen pounds or its equivalent by leverage and with the .self balancing to'the above proportion seven and one-half pounds or its equivalent by leverage. Again the lower pressure area (on the valve V) may be made three-fourths of the area of the upper so that in the case of the one inch valve the downward pressure would be thirty pounds and the upward three-fourths of thirty (equal to twenty-two and one-half)- that is, the amount of the balance by weighting would be thirty minus twenty-two and one-half. (equal to seven and one-half) pounds. With the area one half inch the downward pressure would be fifteen, the upward threefourths of fifteen, equal to (eleven and onefourth;) so the amount to be balanced by dead weight would be fifteen minus eleven and removed altogether. boiler pressure of sixty pounds would open one-fourth (equal to three and three-fourths) pounds. The conditions under which this dead weight may be disregarded are readily seen by studying for a. moment the valve on the steam side, '5. e., the steam driven valve Q. For example take the steam valve of say three inchesarea as against the last example of the other side which gave (with thirty pounds pressureat coil outlet) an effective downward pressure of three and three-fourths pounds. Consider theweight On the steam side the the valveand steam would pass round to the under side and also to the upper reservoir but itis manifest that the steam on the under side cannot rise to the sixtypounds as before, as the valve Q would be shut ofiby the action of the three and ,three -fourths pounds on the other valve V. Now the area of the steam piston Q has been taken at three inches; therefore when the steam on the under side risesto sixty minus one-third of three and three-fourths (equal to sixty minus one and one-fourth, equal to fifty-eight andthreefourths) the steam valve Q will be in equilibrium and as it rises above this the valve V will again open to the coil 0. Now as the steam has thereby been shut off before the boiler pressure was reached a sufficient extra drop from theupper reservoir J will have to be allowed (this amounts to weighting the valve against the live steam.)

It will be readily seen that the larger the steam valve or the greater its leverage is compared to the coil valve-taking their efiective pressure areas--the more control has the former over the latter, this control in the above case amounting to dispensing with the weight on the steam side; and with the upper reservoir at a sufiicient height the pressure in the coil mayvarygreatly without affecting theaction of the valve in forcing the water back to the boiler.

As I have. already stated I may use adashpot or other device for regulating. This may be put in the coil side of the valve itself and is shown in Fig. 3 where by a bypass it is effected that when the coil valve V is closed (1'. e. up) it is in the state of partial equilibrium described butwhen it is open (2'. e. down) it has the full area of the top pressure only so that the pressure on the steam side has to fall lower (below the steam piston) in order that it may allow the steam pressure on the top of steam side to open.

In the above case it was shown that when the steam on the under side of steam valve was fifty-eight and three-fourths equilibrium full area of pressure--viz., fifteen poundss0 that the steam has to fall one-third of fifteen (equal to five) before equilibrium is established on the steam valve thus delaying the action of the steam exactly as required.

It will be obvious that my present invention may be carried into practice and modified in various ways without departing from the nature of my invention -as various details'of construction and arrangement of parts may be altered or modified according to the varying conditions under which my invention may be required to act and as to which any one skilled in the art or other competent person would be able to decide according to the surrounding circumstances.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is-

1. In apparatus for automatically returning water of condensation feed or other water into steam boilers having a circuit or continuous pipe'systemconsisting of the main steam supply pipe the coil or steam using device and the return pipe leading into the boiler below the water level thereof-the combination with and introduction into such circuit or system (between said steam using device and the return pipe) of a valve apparatus consisting of a steam valve having direct communication on one side thereof with and actuated in one direction by the main steam supply and on the other side thereof communicating with the return pipe and connected 'to a second and separate valve so that the movement of one valve causes movement of the other the said second valve having communication with and actuated in one direction by the pressure existing or remaining in the coil or steam using device substantially in the manner and for the purposes hereinbefore described. I

2. In apparatus of the character described having a back pressure valve such as a close to the inlet into boilerthe' arrangement and combination therewith of valve apparatus having a steam valve working in a cylinder connected on one side of the valve to the full steam supply and on the other side thereof with the return pipe, a steam passage from such cylinder controlled by said valve and leading to the accumulated water in a reservoir pipe or chamber such as H interposed be tween said steam passage and the return pipe, and acting in conjunction with a back pressure valve such as 0 so that such water is driven by such steam through the return pipe and higher reservoir J substantially in the manner and for the purposes hereinbefore described. I

3. In an apparatus of the character described, the combination with a steam gener ator and a feed water supply, of a valve apparatus consisting of a steam valve with live steam connection to the generator, and a second valve moving synchronously with and in reverse direction to said steam valve, and connected to the feed supply, reservoirs connected to each other and to said.valves,-back pressure valves between said reservoirs, a feed pipe connecting the last reservoir and the steam generator, and a back pressure valve in said feed pipe, substantially as and for the purposes described, w I

4. In an apparatus of the character described, the combination with a steam generator and a feed water supply, of a valve apparatus consisting of a casing provided with connections to the generator and to the feed supply, two valves mounted in said casing .andadapted to move synchronously, the said valves being provided with ports and connecting passages, substantially as shown; a reservoir H beneath said valve casing, and connected to each of said valves; a reservoir N connected to said feed supply and to one of said valves; a reservoir J connected to the other of said valves and to the said generator, the said reservoir J being at a higher level than the Waterin said generator; and back pressure valves between each pair of said reservoirs and between said reservoirs J and said generator, substantially as and for the purposes described. I

5. In an apparatus of the character described, the combination with a steam generator, a steam using device and meansof condensing the steam used in said device, of a valve apparatus consisting of a steam valve with live steam connection to the generator, andasecond valve movingsynchronouslywith and in reverse direction to said steam valve and connected to the exhaust, reservoirs connected to each other and to said valves, back pressure valves between said reservoirs, a feed pipe connecting the last reservoir an the steam generator, and a back pressure valve in said feed pipe, substantially asand for the purposes described.

6. In an apparatus of the character described, the combination with a steam generator, a steam using device, and means of condensing the water used in said device; of a' valve apparatus consisting of a casing provided with connections to the generator and to the exhaust, two valves mounted in said casing and adapted to move synchronously, the said valves being provided with ports'and connecting passages, substantially as shown; a reservoir H beneath said valve casing and connected to each of said valves; areservoir N connected to said exhaust and to one of said valves, a reservoir J connected to the other of said valves and to said generator, the said reservoir J being at a higher level than the water in the said generator, and back pressure valves between each pair of said reservoirs and between said reservoir J and said generator, substantially as and for the purposes described.

LEWIS J OHNSTONE. Witnesses:

HENRY BIRKBECK, 34 Southampton Buildings, London, England.

THOMAS LAKE, 17 Gracech urch Street, London.

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