US 2069163 A
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Description (OCR text may contain errors)
Jan. 26, 1937. DE LOS E. HIBNER, JR 2,069,163
BEARING DEVICE FOR SOOT BLOWER ELEMENTS Filed Nov. 20, 1955 'j'ezferi/or;
k W- /LWW Patented Jan. 26, 1937 ATENT FFIE BEARING DEVICE FOR SOOT BLOWER ELENEENTS De Los E. Hibner, .lr., Du Bois, Pa., assignor to Vulcan Soot Blower tion of Pennsylvania Corporation, a corpora-- Application November 20, 1935, Serial No. 50,662
It is common practice in steam generating plants to employ means for blowing jets of steam across the water tubes, in order to remove soot and other foreign particles therefrom. The 'cleaning elements are usually tubes provided with nozzles distributed along the same, the tubes being rotatable about their long axes. It is also the usual practice to support the tubular cleaning elements upon the boiler tubes; mounting on the boiler tubes bearing devices through which the cleaning elements loosely pass. It is necessary that these bearing devices be firmly held in place for, if they become loose, they will fail in their purpose of properly supporting the cleaning elements. Sometimes the bearing devices are welded to the boiler tubes, but this method is not satisfactory and, in some situations, is actually objectionable. Resort is therefore usually had to clamping devices which embrace the boiler tubes and are caused to grip the same upon tightening bolts forming parts of the clamping devices. These bolts usually pass through the free ends of cooperating clamping members whose opposite ends have interlocking shoulders which hold them together while permitting the free ends to swing from and toward each other. It is obvious that under the high temperatures to which the clamping devices are subjected in actual use, all parts thereof, including the bolts, undergo a substantial amount of expansion; this expansion being often sufiicient to loosen the clamps and destroy their usefulness as bearings for the cleaning elements.
When the clamping elements are massive and have good heat-conducting contact with the boiler tubes, the bolts may be fairly well shrouded with what consists of relatively cold metal; the clamping members rapidly transferring the heat taken up thereby to the boiler tubes. How 'ever, when the bearing devices with their clamps must be made from heat-resisting chrome alloy, the high cost of material militates against the employment of the massiveness that is entirely feasible in the case of cast iron members. Furthermore, the machining of parts composed of heat-resisting alloy, to insure good thermal engagementbetween them and the boiler tubes is a costly operation. As a result, in situations where the temperatures are so high that cast iron bearing devices cannot withstand them, the lighter, less perfectly fitting boiler tube gripping elements composed of heat-resisting alloys have not served to keep the bolts sufficiently cool to prevent a loosening of the grip through expansion of the bolts combined with the expansion of the alloy members themselves.
The object of the present invention is to produce a simple and novel device of the character described above, in which it shall become unnecessary either to provide massive parts or accurately machined parts in order to prevent loosening of the grip of the device on a boiler tube, or other member that is subjected to high temperatures, through the natural expansion of the metal in the device.
ln carrying out my invention, instead of employing bolts which are in tension under the conditions of their normal use and whose elongation therefore, when heated, tends to loosen the grip of the device, I make use of tightening devices or pressure means which are in compression; whereby the forces that come into play through expansion of the tightening means or pressure devices are complementary to and aid the initial holding forces. Thus, by properly designing the structures, the beneficent forces that are set up through a rise in temperature may fully offset the tendency to loosen the grip of the bearing or clamp by reason of the expansion of the body portions of the latter.
A simple way of carrying out my invention is to construct the device in about the same form as heretofore, except that the clamping elements are caused to cross each other near their free ends. Then, instead of connecting these free ends by a bolt that is in tension, the tightening of the device on the boiler tube is effected by a strut or other part interposed between the free ends of the clamping elements and being in a state of compression. Consequently, when the strut or pressure device is heated it tends to draw the tube-gripping elements more tightly about the tube.
The various features of novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawing, wherein:
Figure 1 is an elevation of one of my improved bearings and clamps, mounted on a boiler tube of which a fragment is shown, and holding a tubular cleaning element properly located with respect to the tube; Fig. 2 is a view similar to Fig. 1, showing the opposite side of the structure from that which appears in Fig. 1; and Fig. 3 is a View which may be termed an edge view, namely a view looking in the direction of the length of the boiler tube, the boiler tube being omitted.
Referring to the drawing, A represents a member that is subjected to flame and hot gases, usually a boiler tube constituting one of a group of tubes from which soot and other foreign matter must be swept from time to time. B is a tubular cleaning element of any usual or suitable construction, shown as crossing above the tube A at right angles to the latter. The tubular cleaning element extends through an opening l, of larger diameter than said element, in a bearing member projecting upwardly from the boiler tube. In the arrangement shown, the bearing member consti tutes a plate-dike part 2 extending radially from one long edge of a half sleeve 3 which fits upon. the boiler tube. Cooperating with the half sleeve 3, which constitutes one element of a clamp, are two narrow, curved strip-like clamping elements A, d which lie on the opposite side of the boiler tube from that on which the part 3 is located. The clamping elements lare shown as having hooks or shoulders 5 at their upper ends for engagement with complementary hooks or shoulders 6 at the base of the part 2. The lower long edge of the half sleeve 3 is flanged downwardly, as: indicated at 1 and, just above this flange, is provided with wide, deep edge notches 8. The lower ends of the parts 5 extend through the edge notches 8 in the part 3 and are so shaped that the extreme end portions 9 lie behind and parallel to the flange 7. Thus, the clamping elements, between which the boiler tube is positioned, cross each other below the tube and the clamp is tightened by forcing the extreme lower ends thereof apart. This may easily be accomplished by inter posing between the flange l and the end portions 9 of the elements 4 suitable devices that are placed in'compression when operated to tighten the clamp upon the boiler tube. In the arrangement, there are two screw bolts lfi, extending through the flange l and abutting at their inner ends against the respective clamping elements 4. When the bolts are screwed in, they act as struts which spread the adjacent ends of the clamp elements apart and tighten the clamp upon the boiler tube. The free ends of the bolts preferably enter sockets H in the parts 9 of the clamping elements 4, tolock these elements against accidental slipping out of the notches 8 in the half sleeve. Furthermore, the screw bolts may be provided with lock nuts l2 to hold them securely against accidental loosening.
It will be seen that when the screw bolts are heated, after the bearing device has been firmly clamped on the boiler tube, the tendency to elongate increases the pressure thereof on the clamping elements. This is due to the fact that the bolts are in compression instead of in tension. Consequently, the tendency of the bolts to elongate, when heated, can serve only a useful purpose; and it becomes unnecessary to try and keep the bolts cool as must be done in the case of bolts which, in the old types of bearings, are in tension and which, if allowed to become too hot, permit the bearing to become loose.
Since the bearing is actually self-tightening, if properly proportioned, the parts thereof may be made comparatively light and need not be machined; these being factors which make the use of heat resisting alloys entirely feasiblein many 7 situations where the high cost thereof has heretofore operated against their use.
' While I have illustrated and described. with particularity only a: single preferred form of my invention, I do not desire to be limited to the exact structural details thus illustrated and described; butintend to cover all forms and arrangements which come within the definitions of my inven tion constituting the appended claims.
I claim: V
1. In combination, cooperating clamping ele- 'ments adapted to receive between the same and grip a member exposed togreat heat, said elements being interlocked at corresponding ends and having free ends crossing each other when in use, of a screw carried by one of said free ends'and abutting against the other of said free ends to cause the screw to be placed in com-- pression when the screw is turned to tighten the. clamp on said member, whereby expansion of j the screw through heating tends to tighten the clamp.
. 2. In a clamping device, cooperating clamping elements adapted to receive between the same and. grip a member and be exposed to great heat, said elements being movably connected at correspending ends and crossing each other toward their opposite, free ends, the free end portionsbeyond the point of crossing of said elements being spaced apart and projecting a substantial, distance outwardly from the main body of the clamp, and a tightening member for said device positioned between the projecting ends of said elements and adapted to be placed in compression to tighten said elements about a member embraced thereby, whereby expansion of said.
tightening member due to a rise in the temperature thereof tends to tighten the grip of the clamping device. 7
3. The combination with the supporting device for a tubular blower element, of clamping elements adapted to embrace and grip a boiler tube, said elements being connected together at one end for relative swinging movements and having their other ends crossing each other and projecting outwardly in a more or less radial di--