US2252962A - Self-cleaning boiler control - Google Patents

Description

Aug 19, 1941- o. F. CARLSON 2,252,962

SELF-CLEANING BOILER CONTROL Filed Nov. 30,4 1940 Patented Aug. 19, 1941 SELF-CLEANING BoILER CONTROL Oscar F. Carlson, Kenilworth, Ill., assigner of one-half to Oscar F. Carlson Company, Chicago, lll., a corporation of Illinois and one-half toy Everett` N. McDonnell, Chicago, Ill.

Application November 30, 1940, Serial No. 367,871 5 claims. V(C1. 137-104) My present invention relates to self-cleaning boiler controls and the like.

In the embodiment of my invention herein disclosed, I have shown and described a float responsive boiler control device secured directly in f the wall of a boiler with the present invention incorporated therein to assure that the control will be kept clean and function in its intended manner, but it will be understood that the invention may be readily adapted to other uses and is not limited only to float responsive controls.

In boiler controls of the type noted, al shield must be provided to protect the float from the ebullient boiler water. The chief disadvantage of this type of installation is that mud and other sediment accumulates and lodges within the shield interfering with the proper functioning of the control and unless the shield is `frequently removed and cleaned the control cannot be de'- pended upon.

The primary object of my invention is toprovide a boiler control or the like which is self= cleaning.

I provide, in the preferred embodiment of my invention, a supporting sleeve or easing, prefer`` ably of circular cross-section, whichmay be selcured directly in the boiler wall to extend out-'- wardly away therefrom and which, preferably, is adapted to support the entireA boiler control mechanism. A tubular shield is disposed Within the sleeve and defines a chamber in which a float member or other operating mechanism is adapted to be disposed. The shield is of a suitable length so that one end portion thereof is adapted to extend within the boiler. The' shield, preferably, is of oblong or elliptical cross-section and the major cross-sectional axis thereof preferably should be substantially equal t'o or slightly less than the diameter of the sleeve and arranged so that this axis is vertically disposed in the-sleeve; With such a construction of supporting sleeve and shield it will be seen that a passageway is formed between each side of the shield and the wall of the sleeve.

The bottom portion of the shield adjacent its end within the boiler is provided with' a plurality of relatively small openings and a relatively large or relatively free opening is `formed in the' bottom of the end of the shield within the sleeve.y Thus when the sleeve is mounted in the boiler wall, one end of the shield is disposed in the hot boiler Water and the other end of the shield is supported in the sleeve outwardly of the boiler wall. The sleeve which is outside the boiler wall loses heat by convection and radiation so that the water in the sleeve loses heat and becomes denser, drops toward the bottom and flows out. With such a construction, convection currents are set up so that the boiler water will ow through the passageways deed by the sides of the shield and the inside wall of the sleeve into the relatively large opening in the end of the shield Within the.

sleeve, along the inside bottom surface of the shield and then through the number of small openings in the bottom of the shield adjacent its end disposed within the boiler. Thus, it will be seen that I have utilized tlie physical property of the` varying density of water due tor its varying temperature to cause a continuous convection current to flow sov that the botton of the shield is constantly being swept by the boiler water keeping the interior' of the shield clean.

It will be seen that if a float member such as is suitable for opening or' closing a switch member of a boiler control device, be disposed within the shield of my present invention, the constant sweeping action will prevent the accumulation of mud or sediment which would clog or interfere with the float. Generally a bellows is incorporated with the float to allow the float to move in accordance with variations in liquid level and in such cases the Abellows will also be kept clean.

Other objects and advantages of my invention will be apparent from the following detail de'- scription.

Now, in order to acquaint those skilled in the art with the manner of constructing and operating my invention, I shall describe in conjunction with the accompanying drawing a specific einbodiment of the invention.

In the drawing:

Figure 1 is a perspective view of a boiler control embodying my invention;

Figure 2 is a longitudinal vertical section of the rboilercontrol of Figure 1; and

Figure 3 is a vertical section taken Substantially on thev line 3-''3 of Figure 2, looking in the direction indicated by the arrows.

Referring now to the drawing, I have shown my invention incorporated in a boiler control l which is adapted to be mounted directly in the wall of a boiler 2. A sleeve on casingr 3 preferably of circular crossesectio'n and of any suitable length is threaded at one end, as at 4, and is provided with an integral'ange 5 at its other end. Various lengths of sleeves 3 may be provided'to meet the requirements of various boilers. An annular mounting plate 8 seats in the open end of the sleeve adjacent the flange 5 and is secured to the latter by means of an annular flanged mounting ring 9 by means of cap screws I8. A gasket I2 is interposed between the sleeve 3 and the plate 8 to provide a fluid tight seal. A tubular shield member I5 of substantially elliptical or oblong cross-section, the major crosssectional axis of which preferably is substantially equal to the diameter of sleeve 3 is disposed within the sleeve 3 with the axis referred to extending substantially vertically, so that the sides I6 of the shield, together with the inside wall of the sleeve, define passageways I1-I1. The shield preferably is made of a relatively thin sheet of copper, or copper alloy, or other corrosion resisting material which is shaped, as above described, by positioning the free edges -2Il of the sheet over each other and suitably securing the edges together as by providing one of the edges with a plurality of integral spaced ears or tabs 2l, which are adapted to be inserted through correspondingly spaced slots along the other edge and then bent over. One end of the shield I5 is closed by means of a wall member 23 which is fixed closely adjacent that end by means of a plurality of tabs or ears 24 integral with the member 23 which are inserted through slots in the shield and then bent over. The mounting plate 8 is provided with an integral flange 21 of substantially the same configuration as the crosssectional shape of the shield I5 and extends a short distance inwardly of the sleeve 3. The open end of the shield is fitted over the flange 21 and secured to lugs 28 formed integral with the plate member 8, by means of screws 3U. A relatively large opening 3| is formed in the bottom portion of the shield I5 adjacent the plate member 8 and a plurality of small openings 32 are formed in the bottom of the shield adjacent its other end, the purpose of which will be hereinafter described. A closure plate 35 is secured to the plate member 3 by a plurality of cap screws 36 and a washer 31 is interposed between these members to form a fluid tight joint. An annular supporting or clamping ring 38 is also secured in position by means of the cap screws 36 and this supporting ring is adapted to have mounted therein brackets 4I] for supporting a switch 4I. A switch housing 42 is fixed to the plate member 8 by screws (not shown) and this housing is provided with an outlet 43 for conductors extending from the switch to the mechanism to be controlled, such as a low water cut-off, or other device. 'I'he details of the switch and mounting thereof upon the plate member 8 are not pertinent to the novelty of my present invention and a more detailed description. thereof may be found in my pending application Serial No. 228,566, filed September 6, 1938, for Low water cut-off. A float 45 preferably `of generally cylindrical shape is disposed within the shield I5 which as before noted is of elliptical cross-section so that it may accommodate vertical movement of the float responsive to the liquid level of the boiler. A bellows 45 is secured to one end of the float and extends to a plate 41 which is welded or otherwise suitably secured to the closure plate 35 so that boiler fluid can not enter the switch housing 42. An operating arm or lever 5F! is pivotally mounted upon a horizontally disposed pin 48 which is supported between a pair of ears 43 formed integral with the plate 41. Lever 50 is connected at one end to the float 45 which is adapted to cause the lever 58 to pivot about the pin 48 to actuate the switch lever 5I and plungers 52 and 53 of the switch 4I responsive to the vertical movement of the float 45, as is more fully disclosed in my above referred to application, to which reference is being made.

The shield I5 should preferably be of a suitable length to accommodate a oat of the desired length. It is usually desired to dispose as much of the control within the boiler as possible in order to avoid the external projection of the device. Since boiler tubes or walls may limit the extent to which the shell or casing I5 can be extended inside the boiler, various lengths of sleeves 3 are provided. For best results the end of the shell or casing I5 should extend in to the wall space of the boiler far enough to uncover freely suflicient of the bottom openings 32 to let mud and like impurities be Washed out. It will be seen that one end of the shield being disposed in the boiler water will be maintained at a relatively higher temperature than the other end and the sleeve 3 since the latter are both outside the boiler wall and are cooled by the ambient air. Thus, a convection current will be set up and boiler water will flow through the passageways I1-I1 where the water' will be cooled increasing its density and causing the same to follow a downward path outwardly away from the boiler wall, as indicated by the arrows in Figure l. The water will enter the opening 3I of the shield and will flow along the inside bottom surface of the shield and out through the openings 32 back into the boiler. This convection current will continue as long as there is hot water in the boiler at or above the level of the sleeve 3 so that mud or other sediment cannot accumulate within the float chamber defined by the shield I5 and plate 8 and foul the float 45 or bellows 46. It will be seen that if a low water condition arises the float will drop actuating the switch 4I which may be connected, for example, to a burner cut-off device so that the low water condition will not damage the boiler.

I have tried inserting the control of my invention into position in a boiler with the casing I5 filled up solid with wet core sand. In a surprisingly short time the control cleaned itself completely. It will be seen that the more time the liquid has to lose heat-within limits-the cooler the liquid in the outer part becomes. Hence, the greater change in density tends to create a stronger tendency to set up a circulation.

The boiler control herein described may be mounted in the boiler wall by screwing the threaded end 4 of the sleeve 3 in the opening provided therefor in the boiler wall. After the sleeve has been drawn up tightly the tubular member I5, switch housing 42, and switch mechanism 4I, may stop in an out of vertical position. In order to adjust these several parts in a vertical position, as shown in the drawing, it is only necessary to loosen the several cap screws IIJ and by grasping the switch housing 42, the entire assembly carried by the annular mounting plate 8 may be rotated into a vertical position and secured in this position by tightening the cap screws I0. Alternatively the sleeve 3 may be separated from the remainder of the structure and screwed into the boiler wall separately after which the mounting plate 8 and the parts carried thereby may be secured adjacent the flanged open end of the sleeve 3 by means of the annular ring 9 and cap screws I0.

The sleeve I5 might have substantially its entire inner end open for the entry of the denser water but the arrangement shown provides cptimum effect according to my experience. For best results the openings 32 in the outer end should be only at the lower side of the casing l so as to insure that the flow will carry out solids along the bottom wall where such solids are most likely to accumulate and block the lowering of the iioat. Blocking of the float against lowering may produce dangerous conditions.

It will thus be seen that my invention has overcome in the particular instance described, the chief objection to installing a float control directly in the side wall of a boiler. It will be understood, however, that the invention is not limited to the specific embodiment above described since the invention may be incorporated with widely different devices, but utilizing the teaching of my invention.

I claim:

1. A self-cleaning boiler control or the like comprising in combination, a tubular shield for housing a control member and adapted to be mounted in the wall of a boiler with one end disposed within said boiler and with the other end disposed outwardly of said boiler, said tubular shield having a circulation directing opening at said one end in the lower portion thereof and a circulation directing opening at said other end, there being a passageway extending from said boiler to the circulation directing opening at said other end whereby water from the boiler is caused to flow through said passageway into the circulation directing opening at said other end of said v tubular shield, thence through said tubular shield substantially along the bottom inside surface thereof, and thence out of the circulation directing opening at said one end of said tubular shield back into said boiler.

2. A self-cleaning boiler control or the like comprising in combination, an elongated tubular shield of substantially oblong cross-section for housing an elongated substantially cylindrical float, and means for mounting said tubular shield in the wall of a boiler with its major cross-sectional axis disposed substantially vertically for allowing said float to move in a substantially vertical plane, said means being adapted to support said tubular shield with one end of the latter disposed within said boiler and with its other end disposed outwardly of said boiler, there being a circulation directing opening at each end of said tubular shield in the lower portion thereof, said tubular shield and said means defining a passageway from said boiler to the circulation directing opening at said other end of said tubular shield whereby water from the boiler is caused to iiow through said passageway into the circulation directing opening at said other end of said tubular shield, thence through -said tubular shield substantially along the bottom inside surface thereof, and thence out of the circulation directing opening at said one end of said tubular shield back into said boiler.

3. In a boiler control or the like, the combination of an outer supporting sleeve member of substantially circular cross-section adapted to be mounted in the wall of a boiler in communication therewith, and an inner tubular shield of substantially oblong cross-section the major crosssectional axis of which is substantially equal to the diameter of said sleeve, said tubular shield having a circulation directing opening in the bottom thereof at each of its ends, said tubular shield being arranged in said sleeve with said major cross-sectional axis disposed substantially vertically and with one end of said tubular shield disposed within said boiler and with the other end of said tubular shield disposed outwardly of said boiler, said tubular shield and said sleeve dening a passageway extending from said boiler to the circulation directing opening at said other end, whereby water from the boiler is caused to iiow through said passageway into the circulation directing opening at said other end of said tubular shield, thence through said tubular shield substantially along the bottom inside surface thereof, and thence out of the circulation directing opening at said one end of said tubular shield back into said boiler.

4. In a boiler control or the like, the combination of an outer generally horizontal sleeve member of substantially circular cross-section adapted to be mounted in an opening provided therefor in the wall of a boiler and in communication therewith, an inner generally horizontal tubular member of substantially oblong cross-section the major cross-sectional axis of which is substantially equal to the diameter of said sleeve, said tubular member being adapted to be disposed within said sleeve with an end thereof extending inwardly of said boiler wall, said tubular member being adapted to house a oat and having circulation directing openings adjacent its ends, and means for adjusting said tubular member so that said mai or axis is disposed vertically in said sleeve to allow said iioat to move in a vertical plane and to dene a passageway between said tubular member and said sleeve whereby water from the boiler will flow between them and into the circulation directing opening at the end of said tubular member opposite said end disposed inwardly of said boiler through said tubular member substantially along the bottom of the inside wall thereof, and then out of the circulation directing opening at the end thereof extending inwardly of said boiler wall.

5. In a boiler control or the like, the combination of an outer sleeve member of substantially circular cross-section adapted to be mounted at one end in an opening provided therefor in the wall of a boiler, a mounting member adjacent the other end of said sleeve, a tubular member of substantially oblong cross-section having circulation openings adjacent its ends and adapted to be supported within said sleeve by said mounting member, said tubular member being adapted to house an elongated substantially cylindrical float, and means for adjusting said mounting member so that the major cross-sectional axis of said tubular member is disposed vertically in said sleeve to permit said float to move in a vertical plane, said tubular member and said sleeve dening passageways between them whereby water will iow through said passageways and into the opening in one end of said tubular member through said tubular member and then out of the opening at the other end thereof.

OSCAR F. CARLSON.

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