US1203979A - Boiler-alarm. - Google Patents

Description

C. M. CLARK & R. W. ANDREWS.

-Bom-:R ALARM. APPLICATION FILED FEB. 8, 1912- l.,23,979. PabentedNov. 7,1916. a

2 SHEETS-SHEET I.

' c. M. CLARA@ R. w. ANDREWS.

BOILER ALARM.

APPLICATION FILED FEB. 8. 1912.

Lw. PatentedNov. 7,1916.

2 SHEETS-SHEET 2.

WrrEgn stares Parana Erica CHARLES MOTLEY CLARK AND ROGER W. ANDREWS, OF CHICAGO, ILLINOIS, ASSIGN- ORS, BY MESNE ASSIGNMENTS, TO ERIE PUMP & EQUIPMENT COMPANY, OF ERIE, PENNSYLVANIA,.A CORPORATION OFPENNSYLVANIA.

BOILER-ALARM.

Lacasse.

Specication of Letters Patent.

Application filed February 8, 1912. Serial No. 676,296.

To all whom t may concern:

Be it known that we, CHARLES MOTLEY CLARK and ROGER W. ANDREWS, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful lmprovements in Boiler-Alarms, of which the following is a specication. v

This invention relates to boiler alarms which sound a whistle or other alarm when the water in the boiler becomes either lower or higher than is desired.

One of the objects of the invention is to produce a device which depends for its action directly upon the height of the water in the boiler, and which does not depend upon a float or a diaphragm. It has been found that floats, especially when used with high pressure boilers, become water-logged in time and are also likely to be affected by substances in the water adhering to the float itself, or to other portions of the iioat device.

It rhas also been found that diaphragms are i affected by the high temperature involved in high pressure boilers. And both the float and the diaphragm structures are necessarily inclosed within the boiler, or some adjacent chamber, so that they are not easily accessible. And the object of this invention is not only to avoid the use of the float and the diaphragm, but it is also to place the device entirely in the open where it is accessible either for adjustment or repairs.

Afurther object of the device is to provide an alarm which isv certain in its action.A

Theoperative portion of the device depends upon the expanding and contracting of metal tubes when heated or cooled, the force developed thereby vbeing practically irresistible. The operation of the alarm is thus much more certain than where the force depends upon the buoyancy of a float, or even the pressure of the steam acting upon the diaphragm.

The device consists of a duplex thermostat comprising two expansion and contraction tubes. Normally one of these tubes is filled with water and the other with steam, and the tubes are so arranged and connected with the boiler that. when the water vin the bol-ler sinks below what is called its mini,- mum water level, steam replaces the water in one tube, the tube-is expanded, Aand the whistle valve opened. As soon as the water in the boiler again rises up to its minimum Water level, the ,water replaces steam in the tube, the tube is contracted, and the whistle valve is closed. On the other hand, when the water in the boiler rises above its maximum water level, water passes into the other tubereplacing the steam, the tube contracts, and the steam valve is opened. And, when the water in the boiler sinks to itsmaximum water level, steam replaces water in the tube, the tube expands, and the whistle valve is closed. By minimum and maximum water levels we refer respectively to the lowest and highest levels that it is desired to have the go normally without sounding lthe Patented Nov. '7, 1916..

The thermostat 10 comprises a tube 11 and a tube 12. Tube 11 is composed ofmetal having a high coefficient of thermal expansion. Tube 12 may be composed of metal of a lower coefficient of expansion. s The head 13 of the tube 12 is connected by means 0f a forked link 14 and a pivot 15 with one end of a lever 16. The head 17 of the tube 11 is pivoted directly to the-lever 16. The other end of the lever 16 has an elongated opening 18 therethrough, through which projects the valve stem 19 of the valve 20 which admits steam to the whistle 21. Be neath the end of the lever 16 and threaded on to the valve stem 19 are nuts 22 by means of which the position of the lever with referlower nut serving as a lock nut.

The other ends of the two tubes are ence to the valve stem may be adjusted, the

threaded into the heel 23 of the thermostat.

The Whistle valve 20 is supported by an upright 24 which is threaded at one end into the thermostat heel and at the other end into screw 26, the outer end of the brace encircling the tubes 11 and 12 and being rigidly secured to the tube 12 by means of the set screw 27. The tube 11 is free to slide through the opening in the brace, but is snugly held thereby.

Pipes 28 and 29 are threaded into the heel v 23 of the thermostat, the pipe 28 being connected by means of the heel with the tube 11 of the thermostat, and pipe 29 being connected by means of the heel with the tube 12. Connection is made by means of a tube 30 be# tween each of the tubes 28 and 29 andthe lower end of a waterv trap 31. The upper end of the water trap 31, which is positioned well below the minimum water level, is connected by means of a pipe 32 with the blowoff pipe 33 of the water column 34 of the boiler.

Pipe 11 of the thermostat is connected by A means of its head 17 with the pipe 37 which is connected to the upper valve pipe 38 of the water column. Pipe 12 of the thermostat is connected by means of its head 13 with the pipe 35 which is connected with the lower valve pipe 36 of the water column. At suitable points in these various pipes are placed'unions and valves. It should be understood that the connections to the boiler may be made in any other suitable way, however; care being taken that the connections are at the maximum and,minimum water level points.

l Normally the water in the boiler stands substantially level with the valve pipe 39 in the water column. rllhe limits of safety range somewhat below the pipe 36 and somewhat above the pipe 38 of the water column.

When the water in the boiler is within the v safety limits, the pipes 36, 35, 12, 29 and 30,

and the water trap 31 are filled with water;

while pipes 28 or the upper portion thereof, pipes 11, 37 and 38 are filled with steam; and the position of the thermostat lever is such that the pressure of the steam entering the whistle valve through the pipe 39a is enabled to hold the valve closed. The pipe 39u' may be connected with the boilerat any suitable place above the maximum water level.

When the water sinks in the boiler below the pipe 36, steam passes from the boiler ,into the pipes 36 and 35 allowing the water to How therefrom, and also into the pipe 12 and the upper portion of the pipe 29, the water in pipes 12 and 29 flowing downward into pipe 30 and the trap. The increased temperature of the steam which enters the pipe 12 causes this pipe toeXpand; the pivoted end of the lever 16 is forced upwardly, the other end is forced downwardly, and the steam valve is pressed open by means of the valve stem 19, and the alarm sounds. If water is then passed into the boiler until it rises above the pipe 36, this will cut oil" from the steam portion'of the boiler pipes 35, 12

4.pipe 35 on the other hand will rise substantially at the same rate, so that the water which enters from the boiler will not go beyond the upper bend in pipe 35, while that which enters tube 12 will come from the pipe 30 or the trap 31, and will be at a much lower temperature than the water in the boiler. The tube 12 willbe cooled, it will contract, and will draw downwardly the pivoted end of the lever 16 and allow the steam to force into its seat the face of the whistle valve 20, and the alarm will cease.

.If the water in the boiler rises above the pipe 38, steam in the pipe 37 and the tube 11 will be cut off from the boiler and will quickly condense. The water willthen rise in these tubes, pressed upward by the` boiler steam pressure, and for the same reason as stated with reference to tube 12, cool water from the tube 30 will enter the tube 11v and meet the hot water from theboiler at the upper portion of the bend of the pipe 37.

lTube 11 will be cooled, will contract, the

inner end of the lever 16 will thus be forced downward, and the valve face will be unseated by the stem 19, and the whistle willsound. When the water in the boiler is lowered so that steam again has access to pipe 38, steam will pass into pipe 37 and tube 11, and the contained water will flow down; that in pipe 37 passing into the water column, and that in tube 11 passing into the pipe 30 or the trap. Tube 11 will expand, the inner end of the lever will be forced upward,'and the steam will close the valve. and the whistle will cease.

As indicated, the purpose of the steam trap 31 is to contain sufficient water so that the thermostat tubes will always be filled with water which is at a much lower temperature vthan the boiler water. Although the trap is directly connected to the boiler, yet its capacity and the capacity of pipe 30 are such that the thermostat tubes are always filled with the water contained therein, the'hot water from the boiler merely forcing the cool water from pipe 30 and the trap of the whistle valve. But by providing,by the means suggested, cool water for the tubes', the action of the tubes d-ue to their contraction is almost instantaneous.

Valves 40. and 40u are provided in the pipes 35 and 37 in order that the thermostat may be conveniently cut off from the boiler. If so desired, for any reason, these valves may also be used to form a constricted portion in the pipes 35 and 37. This will cause the water in these pipes to Vfiow upward more slowly than in the tubes `11 and 12. Hence if the 'installation is such that hot water passes over the bends in the tubes 35 and 37 so as to more or less affect the rate of contraction of the tubes, these pipes, or either of them, may be constricted temporarily or permanently by means of the valves 40 and 40a, and the hot water thereby prevented from entering `the thermostat tubes. Valve 4()a may also be used for the purpose of testing the whistle and the action of tube 11. By closing the valve, tube 11 and pipe 37 are cut off from the boiler,

and, if in proper condition, tube 11 will contract and the whistle will blow. Similarly valve 40b may be used for testing the whistle and tube 12. When the valve is open, steam forces the water from tubes 35 and 12 of the thermostat into the trap through the Valve and into the atmosphere, and the tube 12 expands causing the whistle to blow.

It will, of course, be understood that the essential, a large amount of excess motion must be provided for' to take care of any abnormal conditions that may arise.

It will be noticed that the tube 11 contracts and that tube 12 expands to cause the alarm to sound. It has been found 'in practice that the action of tube 12 under similar conditions is much more rapid than that of tube 11. This is due to the fact that tube 12 is heated by the steam more quickly vthan tube 11 is cooled by the water. No

alarm is sounded usually until after a long .period of time has elapsed, and hence the water in tube 12 becomes comparatively cool. As a result there is a considerable. excess contraction of the tube. This lcauses the valve end ofthe lever to rise away from4 the nut on the valve stem. As a' consequence the water which fills tube 11 when high water occurs is likely to be considerably warmer than the water in tube 12, because it usually comes from a warmer location and some water from the boiler itself may traction being in proportion to the length,

the effect necessarily is quickened by lengtheni'ng the tube. By pivoting. tube 11` to the valve lever at the inner point the ratio of the valve arm to the tube arm is greater than the ratio of the valve arm to the tube arm in case of tube 12 with tube 12. Hence the action of, tube 11 is correspondingly quickened. And finally, as the action of tube 11 lis delayed by the excess contraction of the tube 12, decreasing the contractibility of that tube necessarily quickens the action of tube 11.

It will be seen that excess contraction or expansion of either tube is fully cared for. An excess of expansion of tube 11 or contraction of tube 12 will cause the valve arm of the lever to move freely away from the nut of the valve stem sofar as may be necessary. And an excess contraction of tube 11 or expansion of tube 12 will cause the Valve arm to sink and the valve face to be pushed downwardly so far as may be necessary into thel chamber 42.

The valve 20 is of special construction. As stated it is supported on the upright 24 which is threaded into the base of the Valve. The steam enters through the pipe 39?l which is at right-angles to this support. lt has been found thatiin installing an apparatus of this nature it is desirable to be able to allow the' steam to enter from-different directions with reference to the position of the thermostat. To provide for this it is necessary only to rotate the valve on its support, as the axis of the` support and the valve stein coincide. By this means the steam may lenter from substantially any, direction with reference to the plane ofthe thermostat.

In the interior of the valve a lug 41 is provided which projects a` substantial disv tance below the inlet port 43 of the valve. This lug serves two purposes. It has been found that steam entering the valve is much more effective in causing it to vclose if it because of side force acting on the valve, but eliminates entirely any tendency of any portion of the entering steam to. keep the valve open causing practically all of the entering steam to tend directly to close the valve. This construction allows the valve to be used without any provision other` than the steam itself for closing the valve, when at liberty to do so, by the rising of the arm of the lever 16. The lug 41 also provides a chamber within the valve which is normally filled with water. Steam enterig the valve from the boileris condensed, flows into and remains in the chamber 42 until v the chamber, including the upper portion surrounding the valve face and seat, is entirely filled with water. As a consequence the life of the valve is greatly prolonged and repairs are much less needed for the reason, first, that the contained water cools and keeps the valve parts in better condition to resist wear, and further for the .reason that, as is well known, water in contact with the softer metals is much less injurious than steam, steam having an eating tendency which is much greater than Water, especially when the water is comparatively cool. The water also prevents leakage and keeps the parts in a moist condition so that action is more rapid than when the parts are incontact only with dry steam. The valve therefore is especially adapted for use with an alarm of this nature which depends for its value altogether upon the certainty of prompt action and which lies idle over long periods of time. A pin 42a is set in the supporting rod 24, below the valve face to prevent the face from sinking too low when the steam pressure .sinks or ceases altogether.

Fig. 5 shows a modified form of the valvecontrolling mechanism. The lever 16a acts directly upon the valve stem according to the action of the lever 16 hereinbefore described. But a second lever 45 is pivoted to the upper end of the link 46 at the point 47, the link being pivoted to aprojecting lug .48 of the valve casing. The valve stem 19, because of the steam pressure, presses against the lever 16, as with the other form, and the weight 49 assists the steam pressure by forcing the inner end of its lever upward against the nuts 22. Normally the lever 16a allows the weight 49 and the steam pressure to hold the valve closed. When steam enters the tube 12 the tube expands, the inner endof the lever 16a is forced downward; this raises the Weight and forces the valve open. When the tube 12 contracts againthe Weight sinks and the valve is closed. On the other hand, when tube 11 has its steam replaced by water, it contracts,

the weight is raised and the valve is opened. When steam again 4enters the tube, the weight lowers and the valve closes. So that the operation is similar 'to the operati-on hereinbefore described with reference to the other form of mechanism, the weight merely making more certain the action of the valve. This modification is of special value when for any reason a stufling box is used with the valve, or when an ordinary valve is used. An adjusting nut 50 may be placed on the whistle so that the tone of the whistle may be varied in order to make it distinguishable from other whistles, or for any other reason.

We wish it understood that we do not limit ourselves to the details of construction herein shown, for various modifications within the scope of the claims will occur to those skilled in the art.

In the claims attached hereto, by the use of the expressions contractible tube and expansible tube we refer to tubes composed of materials which have a high coeiiicient of thermalexpansiom the contractibl'e tube being the tube which when contracting operates the valve, the expansible tube being the tube Whichwhienl expanding operates the valve. i

We claim as our invention:

l. A boiler alarm comprising a contractible tube, a conductor connected to one end of said tube, said` conductor being adapted to be connected to a boiler at its maximum water level, and a b nd in said conductor extending above said ube; one end of said tube being rigidly supported, and the other end of said tube being` adapted to actuate a .device when said tube contracts.

its minimum water level, said conductor having a bend extending above said tube, the

other end of said tube adapted to be connected to the boiler below its minimlum water level, one end of said tube being rigidly su ported, and the unsupported end of said tu e adapted to operate a device when the tube expands.

3. "A boiler alarm comprising a contractible tube and an expansible tube, a. first conductor connected by one end with one end of said contractible tube; said conductor adapted to .be connected .with a boiler at its maximum water level and having a bend therein above said contractible` tube, a second conductor having one end connected to one end of said expansible tube, vthe other end of said second conductor adapted to be connected. with the boiler at its mimmum water level and having a bendtherein above said expansible tube, the other ends of each" of said tubes being rigidly supported and being connected with a third conductor, said third conductor being connected with the boiler below its minimum water level, a water trap iny said third conble tube, an expansible tube, and a lever,

one end of said contractible tube adapted A' to be connected with a boilerat its maximum water level, one end of said expansib'le tube adapted to be connected with the boiler at its minimum water level, one end of each of said tubes being rigidly supported, ysaid tubes being composed of material of different coefiicients of thermal expansion, the

free ends of said tubes being pivotally connected adjacent to each other near one end of said lever, the other end of said lever being adapted to be `operatively connected to an alarm device.

5. A boiler alarm comprising metal tubes of unequal lengths, and a lever, said tubes being adapted to be connected with a boiler respectively at its maximum and its minimum water level, the other ends ofsaid tubes beingl adapt-ed to be connected to said boiler below its minimum water level, one

end of each of said tubes beingrigidly supported, the-other ends of said tubes being pivotally connected adjacent to each other to one` end of said lever, and the other end of said lever being adapted to be operatively connected to an alarm device.

6. A boiler alarm comprising a contractible tube and an expansible tube of unequal lengths and of unlike coeiiicients of thermal expansion, one end of one of said tubes being adapted to be connected to a boiler at its minimum water level, one end of the other of said tubes being adapted .to be connected to said boiler at its maximum water level, one end of each of said tubes being rigidly supported, thel unsupported ends of said tubes being pivotally connected adjacent to each other near one end of said lever, the other end ofV said lever being adapted tobe operatively connected to an alarm device.

7. The combination of a boiler, a device, and a boiler alarm, said' alarm comprising two thermostatic tubes and a lever, one en d of one vof" said tubes being connected with the boiler at its maximum water level, one end of the other tube being connected with the boiler at its minimum Water level, one end of each ofsaid tubes being rigidly supported, the other ends .of'said tubes being pivotally connected to said lever adjacent one end, and theother end of said lever when operated by said tubes being adapted to actuate said device.`

8.l A boiler alarm com rising a contractible and an expansible tu e, one end'of said contractible tube adapted to be connected with the boiler at its maximum water level, one end -of said expansible `tube adapted to be connected with a boiler at its minimum Water level, a conductor having. one end connected to each of the other endsof said tubes, and the other end of said conductor adapted tov be connected to a boiler below its minimum water level,'and a water trap in said conductor, one end of each of said tubes rigidly supported, the other ends of said tubes adapted to actuate a device when saidl contractible tube contracts or the expansible tube expands.

9. A boiler alarm comprising a contractible tube, a first conductor connected to one end of said tube, and a second conductor connected to the other end of said tube,` said first conductor adapted to be connected to a boiler at its maximum water level, and af bend in said first conductor extending above said tube, said secondconductor adapted to be connected with a boiler below its minimum water level, and a trap in said second conductor below said minimum water level,

one end of Asaid tube rigidly supported, the.

other end of said tube when it being adapted to control a device.

l0. A `boiler alarm comprising an expansible tube, a first conductor. connected by one end to one end of said' tube, the other end of said conductor adapted to be connected to a lboiler at its minimum water level, and a bend in said conductor extending aboye said tube; a second conductor having one end connected to the other end of said tube, the other end of said second conductor adapted to be connected to a boiler below its minimA m water level, and a trap in said second lconductor, one end of said tube rigidly supported, and the unsupported end of said tube adapted to operate a device when thel tube expands.

11. A boiler alarm comprising a contractible tube and an expansible tube, a first concontracts ductor connected by one end with one end of ed with a boiler at its minimum water level,

and a bend in said second conductor above said expansible tube, the other ends of each of said tubes ri idly supported, and the free ends of said tu es adapted tooperate a device when said contractible tube contracts or said expansible tube expands.

12. A boiled alarm comprising a contractible and an expansible tube, and a lever, one end of said contractible tube adapted to be connected with a boiler at its maximum water level,one end of said expansible tube adapted to be connected with theboiler at its minimum water level, one end of each of said tubes rigidly supported,` said expansible tube being composed of material of lower coefficient of thermal expansion than said contractible tube, the free end of said expansible tube pivotally connected to one end of said lever, the free end of said contractible tube pivotally connected to said lever adjacent to said lever end, the other end of said lever adapted to actuate a device, whereby when said contractible tube contracts or said expansible tube expands, said lever will operate said device.

13. A boiler alarm comprising a contracti- ,of said expansible tube pivotally connected to one end of said lever, the free end of said contractible tube pivotally connected to said f lever intermediate its ends, the other end of said lever adapted to actuate a device Whereby when said contractible tube contracts or ,said expansible tube expands, said lever will operate said device.

14. A boiler alarm comprising a contractible tube, an expansible tube, and a lever, one end of said contractible tube-,adapted to be connected with a boiler at its maximum water level, one end of saidexpansible tube adapted to be connected with the boiler at its minimum water level, one end of each of said tubes rigidly supported, the free end of said expansible tube pivotally connected to one end of said lever, the free end of the other tube pivotally connected to said lever intermediate its ends, and the other end of said lever when operated by said tubes being adapted to actuate a device.

In testimony whereof we alix our signatures in the presence of two witnesses.

Witnesses:

ERNEST J. ANDREWS, GEORGE L. CHINDAHL.

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