US1977898A

US1977898A - Foam indicating apparatus for steam boilers

Info

Publication number: US1977898A
Application number: US594571A
Authority: US
Inventors: Seniff Russell Wade
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-02-23
Filing date: 1932-02-23
Publication date: 1934-10-23
Anticipated expiration: 1951-10-23

Description

Oct. 23, 1934. R. w. SENIFF FOAM INDICA'IING APPARATUS FOR STEAM BOILERS Filed Feb. 23, 1932 r i H n n Nu 0% m &M 1 e @M Wm H; MM

Patented Oct. 23, 1934 FOAM INDICATING APPARATUS FOR STEAM BOILERS Russell Wade Seniif, Bloomington, Ill. Application February 23, 1932, Serial No. 594,571

5 Claims.

This invention relates to steam boilers and, more particularly, to devices for indicating the height or amount of foam therein.

The principal object of the invention is the provision of a new and improved device for indicating the presence of foam above a predetermined level in steam boilers of locomotives and of other types of steam engines.

A further object of the invention is the provision of new and improved means for detecting the presence of an excessive amount of foam in steam boilers whereby excessive concentration of soluble salts in the water within said boilers may be prevented with a minimum amount of labor and expense.

A further object of the invention is the provision of a new and improved foam detecting device for steam boilers that is inexpensive to manufacture, which may be easily and readily installed on the conventional steam boiler, that is composed of few parts and that is efiicient in operation.

Other and further objects and advantages of the invention will appear from the following description taken in connection with the accompanying drawing, in whichi Fig. 1 is a side elevation of a portion of a locomotive boiler with parts broken away and showing the invention in position thereon, the boiler being shown more or less diagrammatically;

Fig. 2 is a side elevation of a portion of a boiler with parts broken away and showing the modified form of the invention in position thereon; and

Fig. 3 is a vertical section through the boiler and insulating plug of the modified form of construction shown in Fig. 2 and showing the indicator and the circuit diagrammatically with parts enlarged.

Under certain conditions water in steam boilers tends to foam and froth, and when this be-' comes excessive this foam and froth is carried over with the steam as water into the cylinders,

thus impairing the lubrication of the engine which is likely to cause more or less damage to the mechanism. 7

While there are probably a number of causes contributing to foaming, one of the principal causes is the concentration of dissolved salts in the water of the boiler. It has been found by experiment that in the average locomotive boiler which operates around 200 lbs. pressure at 387 degrees Fahrenheit, the water will foam when the concentration of the soluble salts inthe water amounts to about one part in 250. Sudden increases in load, that is, increase in use of steam,

more especially when the water in the boiler is at the foaming stage, will cause excessive foaming due to the temporary release of pressure on the water and to the consequent excessive generation of steam throughout the mass which violently agitates the same.

In order to prevent foaming, it is common practice for the engineer, or operator, to blow off the boiler at frequent intervals and to introduce fresh water in' order to lower the ratio of the soluble salts in the water.

Such practice results in loss of excessive amounts of hot water and consequent loss of fuel due to the fact that the engineer, or operator, having no means of determining the amount of water tobe discharged, andin order to be safeinvariably blows off the boiler in excess of the amount necessary. The present invention seeks to remedy these difficulties by the provision of means for determining when there is an excessive accumulation of foam in the boiler.

It has been determined by actual tests thatthere is under normal operating conditions an average fuel waste of 2.7% due to the heat lost in the excessive water discharged from the boiler to prevent foaming. This waste of heat units may be saved by the use of some means for indicating to the engineer the foam condition of the boiler so that only the amount of water concentrate necessary to prevent excessive foaming need be discharged.

The engineer, by observing the indicator, may, with a little experience, learn to prevent excessive foaming in the boiler with a minimum amount of heat loss.

Referring now to the drawing, the reference character 10 designates a locomotive boiler'having the usual fire box 11, crown sheet 12, flues 13 and steam dome 14, as are usual in such constructions. 'The boiler is also provided in one of its water legs with the usual blow-off valve 15 which is operated by the lever 16 within the cab 17 in the usual manner. 7

The parts thus far described are shown more or less diagrammatically and may be of the usual or any well-knownconstruction. Since the details of these parts constitute no part of the present invention, it is not thoughtnecessary to describe or illustrate the same. 1

Suitablemeans are provided for indicating to the engineer when the foam in the space 18 above the water level reaches a predetermined height. 1

'It has been. found by extensive experiments that foam willconduct electricity and this pr0perty of the foam is utilized to indicate its height in the boiler.

In the form of construction selected to illustrate one embodiment of the invention, which is by way of example only, an electrode 19 is secured in the shell 21 of the boiler above the normal water line. It is insulated from the boiler. similar to a spark plug. This electrode is connec'tedwith a suitable source of electric energy as the generator 22 and with an indicator 23.

The indicator may be in the form of an electriclamp 24 within a casing 25 which is provided with a bulls eye 26 opposite the lamp 24 of any distinctive color, as may be desired. The electrode 19, generator 22 and indicator 23 are shown as being in series and grounded as at 2'? on the boiler.

The lower end of the electrode is located a predetermined distance above the normal water line of the boiler and when sufficient foam accumulates within the boiler to come incontact with the electrode to close the circuit, the signal will be energized to indicate to the engineer the presence of foam within the boiler. I

If desired, a plurality of electrodes may be employed for indicating different heights. In the form of construction shown in Fig. 1, two

electrodes

19 and 28 are employed. 7

The electrode 28 terminates at a higher level than the electrode 19 and is in a separate circuit withthe source of current and with a second lamp 31. The lamp 31 has a bulls eye 32 in front of it. The electrode23 may be arranged to terminateat the uppermostlevel that is safe to permit foam to accumulate in the space 18.

, If more than one electrode be employed, they are preferably of different colors. Only two signals are shown and the first signal may be amber and the other red so that the engineer will know that when the amber signal is flashed, the foam is collecting within the boiler but has not reached the danger point. When the red signal is flashed, he will know the danger point is nearor hasbeen reached, depending upon the arrangement of the electrodes and signals.

In the operation of the device, when the foam rises in the space 18 above the water into contact with the lower end of electrode 19 the foam will complete the circuit through the electrode 19, the generator 22 and the lamp 24, thereby energizing the amber signal and when it rises still further and contacts with the electrode 28 the circuit will be complete through the. generator 22 and the lamp '31, thereby flashing the-red signal, and warning the engineer of the presence of an excessive amount of foam in the boiler.

While in the invention described above colored visible signalsare employed, it is. understood that other forms of signals may be used, either visible or audible. a I I For instance, in the form of construction shown, in Figs. 2 and 3 an indicator similar to an ammeter may be employed. In this form of construction, a double electrode 33 is employed. As shown, the? central electrode 34 is insulated from theplug 35 with any suitable insulatingmaterial 36, such as bakelite or porcelain. The other electrode 37 may be in the form of wire wound spirally on'a support 40 which may be of bakelite or other insulat ing material. If desired both terminals, or either, may be of wire supported in any suitable manner. If desired, either or both may bemade of material. having a high electrical resistance, sothat as the foam rises on the same, the resistance to the flow of current will materially increase. The plug shell 35 carrying the electrode 37 is mounted on the boiler shell 21 and the electrode 34 is electrically connected to a source of energy as the battery 33 and to an indicator 39 which, in'turn, is grounded on the boiler as'at 41.

In the operation of thedevice, when the foam rises into contact with the lower ends of the electrodes 34 and 37, the circuit will be completed between the battery, the indicator'and theelectrodes. This will actuate theindicatori 39 for indicating to the engineer the presence of foam within the space occupied by the electrodes. As the height of the foam increases, the resistance of electrodes will correspondingly decrease J with a consequent increase in the strength of the current which will be indicated by the hand 42 of theindicator 39.

'Since the strength of the current will vary inversely as the resistance, and since the resistance will decrease as the foam rises along the electrodes, the indicator 39 which measures the current will indicate the height of the foam in the boiler.

, Instead of arranging the electrodes parallel they may be so arranged that they diverge downwardly whereby asythe height of the foam rises the space betweenthem for the current to traverse will become less and hence the strength of the current will increase, The indicator will respond to this increase and therebyindicate the height of the foam in said space.

. What I claim, therefore, is:

1. A device for indicating the foam level in steam boilers, comprising an insulated electrode extending into said boiler and terminating above the normal water level therein and an electrical circuit connected to said electrode and adapted to be closed when foam in said boiler rises suificiently to contactsaid electrode.

2. A device for indicating the foam level in steam boilers, comprising an insulated electrode extending into said boiler and terminating above the normal water level therein, an electrical cir-- cuit connected to said electrode and adapted tobe closed when foam in said boiler rises sufficiently to contact said electrode and visible signal means in said circuit actuated by the closing thereof.

3. In combinationwith a steam boiler having the conventional boiler shell and crown sheet spaced from the upper portion of said shell to form a steam ,space above the normal water line in said boiler, an indicator and means extending into said .space and terminating above the normal waterline in saidboiler and-normally out of contact with foam in said boiler for operating said indicator'onlywhen foam in said space rises intowhen it rises into contact with another of said electrodes another of said lamps will be energized for indicating the height of foam within: said boiler.

.5. An apparatus for indicating the height of foam within a'steam boiler comprising a plurality of insulated electrodes of materially different lengths adapted to be secured in a boiler shell and occupying positions wholly above the water leveltherein, a source of electric energy and an indicator'device comprising a lamp for each electrode,'each electrode being in electrical connection with said source of electric energy and a corresponding lamp.

. RUSSELL WADE SENIFF.