US1762940A - Safety device for boilers - Google Patents

Description

June l0, 1930. P. c. wooD SAFETY- DEVICE'FOR BOILERS 6 Sheets-Sheet Filed Sept. 22. 1926 June 10, 1930. P. c. woon 13525940 SAFETY DEVICE FOR BOILERS Filed Sept. 22. 1926 6 Sheets-Sheet 2 June l0, 1930. P. c. wooD SAFETY DEVICE FOR BOILERS Filed Sept. 22. 1926 6 Sheets-'Sheet 5 June l0, 1930. P. C. wooD SAFETY DEVICE FOR BOILERS 6 Sheets-Sheet 4 Filed Sept. 22. 1926 fia/e7 June l0, 1930.

P. C. WOOD SAFETY DEVICE FOR BOILERS 6 sheets-sheet Filed sept. 2'2. 192s June 10, 1930.

P. C. WOOD SAFETY DEVICE FOR BOILERS Filed Sepb.- 22. 1926 6 Sheets-Sheet 6 Patented June 10, 1930 I UNITED STATES PATENT oFFllcs,

ranno. woon, or JonNs'roNvInLn, camonm sum nEvIcE ron normas Application ma september as, 192e. serial 110.137,079.'

steam pipe break; and `unless some precau-v tionary measure is taken, the other boilers discharge steam through the main steam pipe into the broken supply pipe, so that after a break in a supply pipe from one boiler, the whole system is for the time being disabled.

An object of a safety system which is so constructed that in the event that anyone of the supply pipes leading from each boiler in a bank of boilers to the main steam pipe becomes broken, this supply pipe will be automatically shut off so that steam cannot discharge through 1t from the main steam pi e.

Another object o this invention is to rovide a safety systemhaving a device w ich shuts off the supply pipe and which has associated with this device mechanisms which will automatically shutdown the boiler having the broken supply it from the system, so that the remaining boilers in the bank can continue to deliver steam at the desired pressure into the main steam pipe.

Other objects of this invention are to pro-y the line 12-12 upon Fig. 9,

vide constructions which will be automatically operated in the event that a supply pipe breaks to increase the feed water supply to the boiler which has become disabled, shut off the fuel supply, close thevalve leading from the steam dome of the disabled boiler into the supply pipe, release or open the safety valve, increase the speed of rotation of the fan which may be present for creating the draft through the boiler compartment, and operate a signal indicating that the supply plpe has been shut down.

With the foregoing and other objects in view which will be made manifest in thevfollowing detailed description and specifically pointed out in the appended claims, reference `the improved safety system,

this invention is to provide pipe and disconnect has been brokenl and that the boiler is had to the accompanying-drawings for an illustrative embodiment of the invention, wherein Figure 1 is a diagrammatic view illustrating one of a bank of boilers provided with Fig.' 2 is a partial sectlonal view illus dome of the boiler and trating the steam mechanism associated therewith,

Fig. 3 is a partial view illustrating a portion of the supplypipe having the check valve therein and the valve adapted to be opened thereby to permit theflow of steam through the pipes of thesafety system to operate the various other mechanisms,

Fig. 4 is a vertical section taken substantially on'the line 4'-4 ofFig. 3,

Fig. 5 isfan enlarged vertical section taken on the line 5--5 -upon Fig. 4,

Fig. 6 is a vertical section taken on-the line 6 6 of Fig. 5,

' Fig. 7 isa vlew similar tol Fig. 5 showing the valve in its closed position,

Fig. 8 is a. view similar to Fig. 6 illustratingv the valve in'closed position,

Fig. 9 is a vertical section through one of the `self-closing valves employed in the system,

Fig. 10 is a view similar to Fig. 9 showing the valve in closed position,

Fig. 11 is a vertical section taken on the line 11--11 upon Fig'. 10, Fig. 12 is a horizontal section taken upon Fig. 16 is a vertical section taken on the line 16-16 upon Fig. 14,

, Fig. 17 is a horizontal section taken on the Fig. 18 is a horizontal section taken on the the boilers of a bank, showing the manner of connecting my safety device thereto.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, the boilersl which may be of any desired or preferred construction are illustrated as being disposed within a boiler compartment 11. These boilers constitute all or a portion of a bank or system of boilers such as depicted in Figure 19, and each serves to supply steam through a supply pipe 12 to the main steam pipe 13 to which the various boilers are connected by similar supply pipes. The feed Water pipe to the boiler is indicated at 14 having a branch pipe 15 through which water can also be sup,

lied to the boiler. Fuel is supplied to the Boiler furnace through the fuel pipe 16. When the boiler is enclosed within a boiler compartment such as is shown at 11, there is usually a vent pipe 17 wherein there is a fan 18 driven by a steam turbine 19 or the like which is supplied with steam from any suitable source through the pipe 20. This fan serves to create a draft through the boiler compartment.

As previously stated, it not infrequently happens that the supply pipe 12 leading from each boiler 10 to the main steam pipe 13 breaks. In such an event, and if there is no safety device in this pipe, steam from the main steam pipe 13 is discharged back through the supply pipe 12 to the break. To prevent such a contingency in the improved system one or more check valves are installed in the supply pipe 12. These check valves are indicated generally by the reference character 21, and vthey are shown in detail in Figs. 3 to 8 inc. Each check valve consists of a body 22 which is bodily inserted in the supply pipe 12'and held in place by bolts 23 passing through ianges thereon and companion flanges on the supply pipe. A valve closure 24 is disposed within the body and is mounted at its bottom upon a transverse rotatable pintle 25. This valve closure is capable of being swung into an upright position so as to seat upon the seat 26. Normally, however, the valve closure 24 assumes a position such as is shown in Fig. 5 resting on the top of an adjustable set screw 27. In the event that the pipe 12 should break, steam from the main steam pipe 13 would tend to rush back through the pipe 12 to the break. As soon as this reversal of iiow of steam takes place, the steam on striking the inclined valve closure 24 will swing it into its upright position, closing the supply pipe 12 and preventing further discharge of steam from the main steam pipe 13 through the break. If the supply pipe 12 is very long, it is desirable that several of these check valves be employed, whereas if the supply pipe 12 is short, only a single check valve need be u'sed, the single valve 21 preferably being arranged as close tothe main steam pipe 13 as convenient.

The transverse pintle 25 has on its end two arms 28 and 29, the arm 29 being connected by a coil spring 30 to the side of the body 22 so that the coil spring 30 urges the valve 24 into its open position. The arm 28 has a link 31 pivotally connected thereto which in turn is connected to a pin 32 which slides through a sliding plate 33 and has a coil spring 34 disposed thereabout between a nut 35 and a shoulder 36 on the sliding plate 33. The sliding plate 33 constitutes a part of a selfopening valve which is disposed in an auxiliary steam line 37. This auxiliary steam line is supplied with steam from any suitable source, such as an auxiliary steam boiler or one of the other boilers of the bank of boilers. The self-opening valve consists of a body 38 in which is a sliding disc closure 39 having a valve stem 40. The valve stem 40 extends through a packing box 41 and through a frame having a cross member 42. A coil spring 43 is compressed between the cross member 42 and a spring seat 44 so that it urges the valve into open position. The sliding plate 33 has a keyhole slot 45 formed therein through the largest portion of which the maximum diameter of the valve stem 40 is capable of passing. The valve stem has a portion of reduced diameter which is just capable of entering the smaller end of the keyhole slot 45. Normally the sliding plate 33 is in the position shown in Figs. 3 and 4, wherein the smaller portion of the valve stem 40 is iitting within the smaller end of the keyhole slot. When the check valve 24 is shifted into closed position, rotation of the pintle 25 causes the sliding plate 33 to be lifted. This so positions the keyhole slot 45 that the valve stem 40 can easily slide through it and the expansion spring 43 then becomes effective to move the valve 39 into open position, permitting steam to flow through the auxiliary steam pipe 37 from its source of supply.

By thus opening the auxiliary steam pipe, a number of different events are caused to simultaneously occur to shut down the boiler which has become disabled. One of these events is as follows: The auxiliary steam pipe 37 is connected to the cylinder 46 of a self-opening valve generally designated at 47. This self-opening valve 47 is illustrated in detail in Figs. 14 to 18 inc., and controls the flow of water through the branch feed water pipe 15.

The details of the self-opening valve 47 are as follows: The valve consists of a body 48 in which there is a disc closure 49 having a valve stem 50 extending through the packing box 51 and through the top of the frame 52. The frame has a crossbar 53 and a coil spring 54 is compressed between the cross bar 53 and the spring seat 55on the valve stem 50. The

expansion coil spring 54\urges the valve stein 50 to be lifted, moving the closure 49 into v open position. A sliding plate 56 has a keyquite quickly.

'hole slot 57 therein' in the narrow end of which only the upper reduced` end 58 of the valve stem is receivable.. 'In the large end of the keyhole slot the maximum diameter of the valve stem 50 is capable of passing. v'The :sliding plate 56 is connected lto 4a piston rod 59 of the piston 60 which is reciprocable in the cylinder 46. When steam entersthe cylinder 46 from the auxiliary steam pipe 37, it

I' moves the piston 60, causing the sliding plate 56'to be shifted so that the valve stein y50 can pass freely' through it through the large end of .the ke hole slot. lThe expansionspring i 54 then lifts the valve stem andcauses the closure 49 to-be moved into open position.

" This permits an increase of feed water to be supplied to the boiler 10 through the branch feed water pipe 15, and this quick increase of feed water to the boiler serves to cool it down The self-opening valve just vdescribed can be reset by a jack screw 61 threaded through a'yoke 62 mounted on top of the frame 52 and which may berotated by thevh'and wheel 63.

In this way the valve'stein 50 can be forced Vdownwardly bythe jaek screw-against the action of the spring -54L The end of the cyl inder 46 has a removable-plug 64 and the piston has a drilled and tapped hole 65, lse that by removing'the plug 64 an eye-bolt oi fthe like indicated in dotted lines at 66 in Fig.

17 can be screwed'into the piston and serve to'pull it toward the .right to shift the slid g ing plate 56 so that the narrow end of th( keyhole slot 57 will receive'the reduced end 58 on the valve stem 50,` After this'has been done the jack screw 61 is then'screwed back into its uppermost position, the eye-bolt 66 removed and the plug 64 replaced. In this manner the valve can be reset.

Another event which occurs on opening the auxiliary steam pipe 37 is to-cut ofi' the supply of fuel to the boiler 10 which has been disabled., In the. fuel supply vpipe 16 there is disposed ai self-closing valve. generally designated at 67, and the details of construction of this self-closing valve are illustrated in Figs. 9 to 13 inc. The self-closing valve has a body 68 disposedin the fuel supply pipe 16, a disc-like closure 69, a valve stem 70, a

packing box 71 through which the valve stem extends, and a frame or yoke 72 through which the upper end of the valve stem is slidable. The top of the frame has a crossbar 73 and an expansion coil spring 74 is compressed between this crossbar and the spring seat 75 on the valve stem, urging the valve stem downwardly so that the closure 69 will assume a closed position. Fastened to the frame 7 2 is a cylinder 76, in which a piston 77 is slidable which is connected to a sliding plate 78 having a keyhole slot 79 formed therein, the narrow end of 'which is capable of receiving only the portion of the valve stem whichv isof reduceddiameter. as indi- [cated atv 80.V The large'endfof thekeyhole j'slot 79 is capable of receiving the large diamgeterof the va1ve'stem i '-The cylinder 76 is y'connected to the auxiliary Vsteam'pi""ef:l7 and when steamis su'p'pliei'in to it,j th'e piston will move, shifting the sliding p1ate'78, releasing the valve stem and allowing thevs ring 74,to move theva'lve 'intfo vclosed position, thus shutting off thesu' l of fuel to the boiler Nintirely. This self-closing frame through which ajack screw 8 2 extends which is threaded vinto thev hand wheel 83. 1 The lowerend offthisjack screw is provided with afsocket on'which there' is a set screw,

584 permitting it to bejattached to the top of the valvesteni 70 to lift-"the valve, stem against the action off-thecoil spring .74.v The piston`77and the. sliding plate ,-78 canthen returned totheir nor-mal position; to hold the valve ope',j"after'wh1chtheset screw 84 is loosened t'opermitmthe upperisendrof the valve stein ,to pass out of: the' socket and the valve to be closed when thepiston7 7 is actu; ated. V1,210." 1 -A self-elo iig is lsimilar yvalve rcan jbe reset or opened by a yoke'Slfniountedon top of rthevf'bY in construction tothe valve-just described is inserted 'inlfthe'supply vpipe-12 between the check valve 21 and the -inainy steam pipe 13. This vself-closing valveis also connected to the auxiliary",steam pipe 37 andjwill also be closed whenithe auxiliary" steam pipe -is opened. V" lhis valve servestgtoform-a positive closurej'in-the supply---pipel112 in addition to the check Valve 21 'Ato-prevent the reversal of low'thereto from the steam pipe 13.

Another. event whichv occurs is the closing of the entrance to thesupply pipe 12 leading from the steam boiler 10. vOnthe top of the steam dome 87 there is mounted' a .body 88 with vwhich the supply pipe 12 connects.

In this body there is a valve seat89 for the t-hrough'the lyoke98f`on the supply. pipe 12.

A coil springy 99'which is vcompressed between the yoke' 98 yand the spring seat 100 urges the valvestem'and'-pistonf93 downwardly, so that the piston restsupon the shoulder 95, and the valve 90:.is removed from its seat 89, allowing' steam from the i boiler 10 to passy through-the'. supply pipe 'which' leads to the cylinder 95 below the piston 93 and may be supplied with steam from any suitableisource such` as the main' st eam pipe 13, .another boiler inthe bank of boilers or an auxiliary steam boiler. The break in the steam pipe 12 will cause a reduction of pressure on the upper side of the piston 93 and the supply of steam under hi h pressure to the under side of the pistont rough the steam pipe 102 causes the piston to rise, causing the valve 90 to seat on the valve seat 89, thus shutting off the supply of steam from the boiler through the supply pipe 12, so that only a minimum amount of steam will .escape through the break in the supply pipe 12 to the interior of the boiler compartment. The pipe 102 will, 'after the opening of the valve 101, maintain suflicient pressure under the piston 93 to keep the valve 90 closed, even after pressure within the boiler 10 has been considerably reduced. Because of this closing of the entrance to the supply pipe 12, it is practically necessary that the safety valve on the boiler be opened, so that what steam is in the boiler can easily escape therefrom.

The safety valve may be of any preferred construction and is indicated generally at 45g der 107, in which there vagspring 114L andrhas its lower 103 having a valve stem connected to a pivoted lever 104 which can be lifted by a cable 105 or the like. The safety valve is connected to a pipe 106 which will convey the steam out of the compartment. To accomplish the opening of the safety valve the auxiliary steam pipe 37 is connected to a cylinis a piston having a piston rod 108 urged into its uppermost position by a spring 109. The piston rod car- 110 which is capable of re- 'slot rtherein and which "is urged into that positionijhythe spring 113, whereby the rod 112 maysslide freely therethrough. flhe rod 112 is'urged intoits uppermost position by end connected to1 .alink 115 carrying a pin 116 which is capable of engaging the under side of the lever 104; ."Steam on being supplied to the cylinderf 10T/will force the piston therein downwardly causing the trigger on its piston rod'to" rlease the sliding plate v111, al-

' lowing the-,spring 113 to shift the sliding plate so 'that'the rod 112 can be lifted by the spring'lll. VThe pin 116 will then be caused to engagethe under side of the lever 104, liftinglthe safety valve, opening it and allowing the steam in the boiler to pass out through the pi e 106.

It is desira le in the -case of a break in the supply 'pipe 12 to increase the speed of the fan 18 to carry out what steam may have escaped into the compartment. pipe 20 leading to the fan has a branch 117 through which steam may be supplied to the fan from any suitable source. This branch steam pipe 117 has a self-opening valve 118 therein which is connected to the auxiliar steam pipe 37. The construction of the sel opening valve is substantially the same as that previously described in connection with the self-opening valve 4.7 and when opened an additional supply of steam can be supplied to the turbine 19, materially increasing the speed of rotation of the fan 18, thus increasing the draft through the boiler compartment. The auxiliary pipe 37 is also connected to another self-opening valve 119 which is in the steam pipe 120 supplied in any suitable manner and which conveys steam to a whistle 121, so that an audible signal can be given-indicating that the supply pipe 12 has broken and that the various events as above described have occurred, shutting down the disabled boiler.

In view of the fact that the valve 90, in

opening, must move against the direction off' flow of steam from the steam dome 87, into the head 80, diliiculty mi ht be encountered in opening this valve, a ter the break has been repaired and pressure has again built up within the boiler. Accordingly, an equalizing bypass 126 having a manually operable valve 127 therein, has been provided to lead from thesteam dome 87 to the cylinder 94 above the piston 93, and a branch bypass 128 having a valve 129 therein,connects the interior of the body 88 to the bypass 126' above its valve 127. Controll valves 131 and 132 are interposedin the steam line 12, upon opposite sides of the intersection therewith, of the fittings 96 which communicate with the cylinder 94. After the break has been repaired and pressure has again built up within the boiler, the valve 90 may be opened by first closing both valves 131 and 132, and then opening valves 127 and 129, whereupon steam from the boiler will raise the pressure on the top of the piston 93 and upon the top of the valve 90, sufficiently to overcome the upward pressure of the steam against this valve, resulting in moving the valve to o en position. A drain valve 133 `is provided). in the bottom of the cylinder 94.-, to relieve the pressure under the piston 93, to facilitate this opening movement of the valve 90. It is to be understood-that after the valve 90 has been opened, the equalizing valves 127 and 129 should be closed, and the control valves 131 and 132 in the steam line 12, should be fully opened. l

. From the above described construction it The steam will be ap reciated that a safety system'is' provided or a boiler in a bank o boilers .which, if the supply pipe from anyone of the boilers to the-main steam pipe breaks,

will close the supply pipe against the reversal of flow therethrough, increase the feed water supply to the boiler, shut off the fuel supply to the boiler, -close the entranceto the supply pipe, open the safety valve, 1ncrease the speed of the fan creating the draft around the boiler,l and sound an audible alarm. These various events can also be caused to occur by operating a manual valve indicated at 122 and located on the outside of the compartment. The manual valve 122 may be of a construction very similar to the self-opening valve 47 except that the sliding plate can be caused to slide by a handle 1nstead of a steam operated piston. On opening this valve the steam will be supplied to the auxiliary steam pipe and all of the events will occur as before with the exception of the closing of the check valves 21 which require the reversal of flow through the supply pipe 12 to close them. This manually operated valve can be used whenever there is another mishap besides the breaking of .the supply pipe 12 to shut down and take out the boiler with which it is associated from the system or bank of boilers'.

It will be understood that various changes may be made in the detail of construction without departing from the spirit and scope of the invention as defined by the appended claims. p

' I claim: y .v

1. In a boiler system wherein there are aplurality of boilers supplying a main steam pipe through outlet pipes, means disposed in each outlet pipe automatically preventing the reversal of steam fiow therethrough, and means operable l` y said means for increasing the supply of feed water to the boiler with which the outletpipe is associated.

2. In a boiler system wherein there are a plurality of boilersl supplying a main steam pipe through outlet pipes, means disposed in each outlet pipe automatically preventing the reversal of steam flow therethrough, and means operable by said means for shutting off the fuel supply to the boilerwith which the outlet pipe is associated.

3. In a boiler system wherein there are a plurality of boilers supplying a main steam pipe through outlet pipes, means disposed in each outlet pipe automatically preventing the reversal of steam flow therethrough, and means operable by said means for opening the safety valve for the boiler with which the outlet pi pe is associated.

4. In a boiler system wherein there are a plurality of boilers supplying a main steam pipe through outlet` pipes, means disposed in each outlet pipe automatically preventing the reversal of steam flow therethrough, and

means operable by said means forsimultane'ously closing the entrance to the outlet pipe leading from the boiler and opening the safety valve for the boiler.

5. In a boiler system wherein there are a plurality of boilers supplying a main steam pipe through outlet pipes, means disposed in each outlet pipe automatically preventing the reversal of steam flow therethrough, and means operable by said means for closing both ends of the outlet pipe leading from the boiler.

6. In combination with a pressure generator wherein raw material is converted by heat to a fluid under pressure, and which is located in a compartment and having -a vent pipe leading from the compartment in which there is a steam driven fan, means operable by a single valve for increasing the supply of raw material to the boiler, shutting off the fuel supply and increasing the supply of steam to the fan, said valve being located in the supply pipe leading from the generator and being operable vby the reversal of flow through the outlet pipe.

7. In combination with a pressure generator for converting raw material into a fluid underl pressure having a feed supply pipe and a fuel supply pipe, said generator being located in a compartment, a main pipe, an outlet pipe connecting said generator with said main pipe, -a vent pipe leading from the compartment, a steam-driven fan associated with said vent pipe and operable to create a draft therethrough, means associated with said generator and operable by a single valve upon reversal of flow through said outlet pipe for increasing the supply of raw material to the generator, shutting of'the fuel supply and increasing the supply of steam to the fan.

8. In a pressure enerator having a feed supply pipe and a fguel supply pipe, an outlet pipe leading from the generator to-a main pressure pipe, a compartment in which the generator is disposed, avent pipe leadingfrom the compartment, a steam-driven fan in the vent pipe, and an audible alarm, means automatically operable upon reversal of iow through said outlet pipe for increasing the supply of raw material to the generator, shutting off the fuel supply, closing both ends of the outlet pipe, openingv thesafety valve for the generator, increaslng the supply of steam to the fan, and sounding the audible alarm.

9. In a pressure generator having a feed supply pipe and a fuel supply pipe, an outlet pipe leading from the generator to a main pressure pipe, a compartment in which the generator is disposed, avent pipe leadingfrom said compartment, a power-driven fan in the vent pipe, and an audible alarm, means operable by a single valve for increasing the supply of raw material to the generator, shutting oli' the fuel supply, closing both ends ofthe outlet pipe from the generator, opening the safety valve for the generator, increasing the supply of power to `the fan and sounding the audible alarm, said valve being located in the outlet pipe leading from the generator and being operable by a reversal of flow therethrough.

10. A safety device lfor a boiler having a v fuel supxly pipe and a feed water supply safety device comprising a valve inv said fuel pipe, a valve in said feed. water pipe, sal

supply pipe, mechanism operable by fluid under pressure for opening said -feed pipe valve, mechanism operable by fluid underpressure for closing said fuel pipe valve, and emergency means operable on excesslve escape of steam for supplying Huid under.

pressure to both of said operating mechanisms.

In testimony whereof I have signed my p name to this specification.

u P. C. WOOD.

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