US2904260A - Air cooled blower-type cleaner - Google Patents

Description

' Filed June 9, 1955 Sept. 15, 1959 SCHUELER ETAL 2,904,260

AIR COOLED BLOWER-TYPE CLEANER 2 Sheets-Sheet l 1.. B. SCHUELER ET AL 2,904,260

AIR COOLED BLOWER-TYPE CLEANER Sept" 15, 1959 2 Sheets-Sheet 2 Filed June 9, 1955 .r m3 W m4; m ma wag fl 2 5 5W 0 Unite AIR COOLED BLOWER-TYPE CLEANER The..present invention realtes to blower-type cleaning apparatus, and particularly to improvements in soot blowers ofthe type. intendedfor. installation in high temperature zones of furnaces and the like.

An important object of the invention is to provide an improvedsootblo wer equipped with cooling means constructed .and. arranged in .such manner. thattheblower nozzle and adjacent parts may be installed in high temperature zones, as, for example, in the water walls of large industrial boilers, and will endure for long periods ofQtime when so installed without the necessity for retracting the nozzle during intervals when blowing medium isnot flowing therethrough.

Arelated object is to provide such a construction which is of simple. and inexpensive character, which is compact andflightinweight, which involves no special or. complicated moving parts, which is not apt to become clogged, which has a longlife, and which requires a minimum of attention and servicing.

In the past it has not been found practical to construct the blower-tubes and nozzles of soot blowersintended for such high temperature installations of a material which is capable ofwithstanding the heat-during the periods when theunit is not being cooled by the projection of theblowing medium therethrough, and it has accordingly become universal practice to employ retractable soot blowers in. such installations. Previous efiorts to utilize a cooling medium such as air have. not beensuccessful for several reasons, among which may be mentioned the high radiant heat impingement, and the difliculty involved in the provision of a shielding screen of cooling air. In accordance with the present'invention the exposed portion of the nozzle is covered by a stainless steel shroud which is spaced from the blower tube. Cooling air is caused to flow through the shroud, between the shroud and the blower tube and outwardly into the boiler through an opening which substantially surrounds the nozzle. A substantial proportion of the radiant energy is reflected by the stainless steel shroud, while the remaining extraction of heat is eliected by the cooling air.

Other objects and advantages of the invention will become apparent upon consideration of the present disclosure in its entirety.

In the drawing:

Figure 1 is a vertical sectional elevational view through a portion of aiurnace wall, showing a soot blower constructed and installed in accordance with our invention;

Fig. 2 is a longitudinal central sectional view, on a larger scale, of the blower nozzle assembly;

Figs. 3 and 4 are cross-sectional views taken substantially on the lines 33 and 4-4 respectively of Fig. 2; and

Fig. 5 is a horizontal sectional plan view taken substantially on the line 5--5 of Fig. l, and looking in the direction of the arrows.

Referring now to the drawing, reference character designates the wall of a boiler setting, the details of States Patent 2,904,260 Patented Sept. 15, 1959 2 which are not illustrated, since they form .no partof. our present invention, althougha water wall section is illus trated, as typifying a high temperature regionifor which our invention is suitable. Water wall tubes-as 12sextend vertically inside the wall, which is also provided .with an internalpocket in-the areaofthe opening 14: forthe blower assembly, the pocketbeinglined by-ametalsup port plate 15 covered'on the inside of the furnace/by; refractory cement as 16; The supporting plate carries on its-outer surface amounting plate 18 to which a sleeve 20 is. bolted or. otherwise attached in a position concentrically surrounding, and, projecting-outwardly from the blower tube opening19rin the plates 15,.18.. The water. wall tubes in line withthe opening 19 are bent laterally to provide clearance for the blower, as shown inFigs. 1. and 5,, The construction and arrangement ofthese parts are.essentially conventional, andwill require no detailed description. The blower driving unitis illustrated in outline only, and is generally. designated 22. The details of construction of the blower driving head arealso-subject to variation and form in themselves no part .of our present invention.

The drivinghead is equipped with a. driving motor 24 which when the blower is in operation is arranged to rotate the nozzletube 30.. The, driving head is of the type wherein. the blowing fluid is delivered through the head, to which the fluid is supplied through a suitable supplytube26, the. delivery of the blowing mediumfrom the head beingcontrolled by a valve (not. shown) containedin the head andwhich is operatedby and in response. to rotation-of the driving mechanism. Whenthe. valve is open, the blowing medium is conductedfrom the headthrougha tube 2.8.v The, tube 28 is drivable by the head, and. carries rigidly secured thereto the nozzle block tube.30,,which,.as shown at 32, may.be terminally welded to the-tube28 to forma coaxial extension thereof.

The endoflthenozzleblockv tube 30 projects into the furnaceand-is closed except for the discharge opening 33 defined by the nozzle ring 34, which is welded. as at 35 in a suitable opening in the block tube. The. nozzle blocktube carries upon itsexposed enda caplike shroud member, 36 {largen in ,alLdimensions thant the block, tube, so that its walls are spaced outwardly from 'those of the block tube, the shroud,extendingentirely around the side andend walls-of the block tube which would otherwise be directly exposed to the heat within the furnace, except for the small area represented by the opening 38 which is formed in the shroud in a position substantially concentric with the nozzle member 34. The opening 38 is somewhat larger than the nozzle member 34, to permit air to be discharged from the shroud between the shroud and nozzle ring, as well as to permit the discharge of the blowing medium. The rear portion 40 of the shroud is substantially cylindrical and is open, being held in concentrically out-spaced relation with respect to the block tube 30 by suitable peripherally spaced welded lug portions 42.

A cooling air supply tube 44 extends over the rear extremity 40 of the shroud 36, the shroud being rotatable with the block tube in the outer end of the tube 44. Tube 44 extends rearwardly over the block tube 30 and feed tube 28 to a manifold 45 which encircles the feed tube 2 8 at a position between the driving head and the furnace wall. The interior of the tube 44, which is substantially larger in diameter than the tubes 28 and 30, communicates with the interior of the manifold 45 which is in turn in communication with a cooling air supply pipe 46. The spaced concentric positioning of the tubes 28, 30, 44 is also maintained by spacing lugs '48 which are secured to the tube 28 as by welding and rotate within the tube 44.

The shroud 36 is formed of relatively light gauge stainless steel and it is only secured in the area of the three locating lugs 42. The shroud is thus free to flex under heat-induced stresses. The highly reflective surface of the stainless steel also reflects a substantial proportion of the radiant energy impinging thereon, reducing heat transmission to the block tube 30, which may be formed of ordinary mild steel. The heat transmission is also reduced by cooling air supplied through the pipe 46, manifold 45 and conduit 44 to the interior of the shroud, The air is guided over the entire interior of the shroud before being discharged through the opening 38. p

The cooling air supply may be derived from the air employed to create pressure within the boiler, where the boiler is of the now commonly used positive pressure type, and the air flow is maintained throughout the entire time when the blower is not operating. This cooling air for the blower constitutes one of the means for pres surizing the interior of the furnace. It will be observed that the only area where radiant heat can impinge upon the block tube 30 and nozzle ring 34, is directly beneath the opening 38, and that in this area the concentration of cooling air is the greatest, so that the wiping effect of the air upon these regions is greater than in the other areas inside the shroud and is effective to sufliciently cool these parts despite the impingement of radiant heat thereupon through the opening.

The stainless steel from which the shroud is formed has a highly reflective outer surface and may be so thin as to be easily distortable due to heat induced stresses, as indicated, and would not be stiff enough to support itself and to serve as the nozzle block. Thus it imposes very little weight load on the nozzle block and does not substantially increase the bearing loads or the tendency of the block to sag.

While it will be apparent that the preferred embodiment of the invention herein described is well calculated to fulfill the objects and advantages first above stated, it will be appreciated that the invention is susceptible to variation, modification and change without departing from the fair meaning and proper scope of the appended claims.

We claim:

1. In a soot blower construction, in combination with a relatively rigid blower tube haing a cantilever outer end portion from which blowing medium is adapted to be discharged into a high heat zone and having a nozzle orifice portion in said end portion for discharging the 4 blowing medium, a protective shroud entirely supported and carried by, and spacedly encircling, said outer end portion of the blower tube, and having a discharge opening substantially aligned with but larger than the nozzle orifice, securing means engaging the tube and the shroud at spaced localized areas and forming the entire support for the shroud and securing the shroud to the tube in surrounding but outspaced relation thereto, the shroud being formed of relatively thin gauge, flexible, reflective metal, and having an open rear end, substantially unobstructed cooling fluid passage space being left from the open rear end of the shroud to said discharge opening between said tube and shroud and past said securing means, and supply means operatively interconnected with said open rear end of the shroud for supplying a cooling fluid to the interior of the shroud outside the tube for discharge through said shroud and outwardly through said opening in the region of said orifice, whereby the shroud reflects heat which would otherwise impinge upon said blower tube and serves to conduct cooling fluid supplied by said supply means along and in contact with both the shroud and the nozzle tube, and whereby the shroud may move with the blower tube, during any movement of the latter, due to being carried thereby, and may distort independently of the blower tube in the areas between said securing means.

2. A construction as defined in claim 1 wherein said blower tube and shroud have substantially cylindrical spaced side walls and substantially closed spaced outer ends, the shroud having an open rear end which is substantially concentric with the tube, but being otherwise substantially impervious except in the area of said opening, said blower tube being rotatable, and supply means comprising a non-rotatable feed tube interfitted with the open rear end of said shroud and extending rearwardly spacedly around said blower tube.

References Cited in the file of this patent UNITED STATES PATENTS 1,809,221 Snow et al. June 9, 1931 1,978,686 Moses Oct. 30, 1934 2,022,513 Macchi Nov. 26, 1935 2,052,747 Bishop Sept. 1, 1936 2,192,215 Williams Mar. 5, 1940 FOREIGN PATENTS 286,058 Italy May 30, 1931

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