Патент USA US3054452код для вставки
Sept. 18, 1962 G. E. VALENTINE ET AL 3,054,443 AIR CONTROL MECHANISM Filed Aug. 15, 1959 4. SE SEESQ 5%a%_;é g gzg, rQEG Sw wm United States Patent 0 " "ice 1 3,054,443 AIR CONTROL MECHANISM George E. Valentine and Joseph H. Eubanlrs, Schuylkill Haven, Pa., assignors to Thermo Dynamics Corpora tion, a corporation of Pennsylvania Filed Aug. 13, 1959, Ser. No. 833,428 3 Claims. (Cl. 158-28) This invention relates to blower control mechanisms 3,054,443 Patented Sept. 18, 1962 2 nism operative to leave unrestricted supplementary inlet air ports provided in the blower and to close said sup plementary ports in response to a predetermined rise in combustion chamber temperature or to an automatic time control mechanism. These and other objects of the invention will become apparent as the description proceeds in connection with the accompanying drawings wherein: FIGURE 1 is a partially sectioned front view of a and, more particularly, to improved blower control mech 10 blower constructed in accordance with the instant inven tion and showing the position of the solenoid operated anisms which effect cleaner and more e?icient combustion throughout the ?ring cycle of oil burners and the like. valve when it is inoperative to close the supplementary In the conventional oil burner system, including a air ports provided in the air inlet member of 'the blower; FIGURE 2 is a view in partial section taken along burner, a blower and other associated mechanisms, the air delivery capacity of the blower is usually such that the air 15 line 2—2 of FIGURE. 1; FIGURE 3 is a development of the air volume control delivered to the combustion chamber will be approxi mately equal to the quantity stoichiometrically required band used in association with the novel blower mecha for complete combustion of the fuel when the burner and nism of the instant invention; and its environment are at a predetermined optimum operat-, ‘FIGURE 4 is a schematic diagram of a portion ofthe ing temperature. But while such a design usually pro 20 circuit in which the novel air'control mechanism of the motes e?icient burning throughout the greatest portion of instant invention may be used. Referring to FIGURES 1 and 2 of the drawings, the the combustion cycle, it is ineffective to maintain proper combustion conditions at the beginning of each combus novel air control mechanism of this invention is shown in conjunction with a conventional squirrel-cage blower tion cycle, when the combustion chamber is cold. Under such cold chamber conditions, the quantity of air required 25 10, which comprises a chamber 12 containing a rotor 14, to burn a given quantity of fuel efliciently is signi?cantly a motor 16 for driving rotor 14, and the usual tangential in excess of that required for ef?cient burning in a com outlet section 18 which, through suitable ducting, ulti bustion chamber which is substantially at combustion mately communicates with the combustion chamber 19 of the oil burner shown diagrammatically in FIGURE 4. temperature and, unless such excess air is provided, in complete or “dirty” combustion will occur with the at 30 Projecting outwardly from side wall 20 and surround tendant formation of soot and other undesirable by products. In systems in which the oil burner is used to heat a boiler or the like, this problem of soot formation ing an air inlet aperturre therein (not shown) is a cup like projection 22 having apertures 23, 25, 26 and 27 in its cylindrical side wall 24. Adjustably mounted about and dirty combustion has posed especially vexing prob side wall 24 of projection 22 by means of ?anges 36 and lems, since it has often dictated boiler design on the basis 35 a bolt 38 is an air volume control band 28 having three of cleaning ease rather than on e?iciency of operation. groups of apertures 30, 32 and 34. Air volume control Attempted solutions to the problem have taken various band 23 is so designed that when it is secured in place forms, none of which has been entirely successful. For about projection 22 in the manner shown in'FIGURE 1, example, it has been proposed to increase the air delivery only the central portion of apertures 30 will be in registry capacity of the blower so as to provide excess air at the with aperture 25 in side wall 24, the remaining apertures beginning of each combustion cycle. But though the in band 28 being positioned adjacent non-apert-ured por~ delivery of excess air to the cold combustion chamber tions of said side wall. Since the quantity of apertures 30 promotes e?icient and clean burning at the beginning of is three times as great as the quantity of either apertures each combustion cycle, the continued delivery of the ex 3'2 or 34, control band 128 may be adjusted to expose vary cess air throughout the combustion cycle is wasteful and ing portions of apertures 23, 26 and 27 while leaving highly ine?icient. The use of variable speed motors to aperture 25 fully in registry with a portion of apertures provide the vexcess air only at the beginning of the combus 30 at all times. Prior to operation of the blower, con tion cycle but to reduce the blower capacity when ‘the trol band 28 should be soadjusted about projection‘22 combustion chamber temperature has risen su?iciently that a sufficient portion of apertures '30, 3'2 and34 will be will, of course, eliminate this problem, but only at a in registry with-apertures 23, '26 and 27 to permit deliv prohibitively high cost. Furthermore, mechanical failure of the variable speed control will necessarily result in ery byblower 10 of that quantity of air stoichiometrically . necessary to support combustion in the combustion cham impairment of_proper combustion conditions. ber of the oil burner (not shown) when the burner ;and It is accordingly a primary object of this invention to its environment are at normal operating temperature. provide an air control mechanism for use in connection 55 Combustion under these conditions may be termed “nor with oil burners and the like which will automatically mal combustion.” and inexpensively eliminate unclean burning and the at Mounted adjacent aperture 25 by means of bracket 39 tendant formation of sooty combustion by-products at the is a solenoid 40 having a movable armature 42. Secured beginning of each combustion cycle. to the free end of armature 42 is an arcuate shield 44 Further objects of the instatnt invention are to provide 60 having a radius of curvature identical to that of control an air control mechanism for use in connection with oil band 28 and being of a size su?icient to completely cover burners and the like: aperture 25 when pressed against the control band in the (1) which inexpensively provides an increase of com extended position of the armature. When the solenoid is bustion air to the burner at the beginning of each com not energized, armature 42 will be spring-biased to its bustion cycle and which automatically reduces the air 65 extended position, urging arcuate shield 44 against con flow when the combustion chamber is substantially at the trol band 28 and fully covering aperture 25. temperature of combustion; As shown in FIGURE 4, the blower motor 16 is con (2) which, when rendered inoperative in the event of a nected to a suitable source of power through leads 46 and mechanical or other failure, will not interfere with normal 48, a normally open thermostatic switch 49 being pro 70 vided for control of this circuit. Shunted across leads 46 combustion conditions in the oil burner; and and 48 is a circuit including in series solenoid 40 and a (3) which utilizes a solenoid-operated valve mecha 3,054,443 - 3, 4 . combustion conditions. normally 'closed switch 50 which is controlled by a thermostat 52 which is in turn responsive to the'tempera ture in the oil burner combustion chamber 19. Thermo Furthermore, if desired, the _ solenoid can be energized by means of the ignition and maintained in such energized condition until the ignition period ends. In such a system, of course, the ignition ,. stat .52 isadapted to open switch 50 when the tempera ' ture in‘ the ,combustion chamber is sufficiently high to period would have to be extended for a sut?cient period lsupport combustion therein e?iciently and without the f formation of undesirable by-products. In operation, power is supplied to blower 10 upon > tional air is no longer required to maintain 'e?icient com ' bustion conditions in the combustion chamber. of time to leave aperture 25 open until such time as addi The present embodiment is therefore to be considered be made responsive to ambient temperature in a room to 10 in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims " be heated.‘ Simultaneously with the starting of blower _ closingof thermostatic switch 49, which may, if desired, ' ratherthan by the foregoing description, and all changes 10, solenoid 40 will be energized, drawing armature 42 7 which come within the meaning and range of equivalency [audits associated arcuate shield 44 away from control of the claims are therefore intended to be embraced '_band 28, leaving in unrestricted condition aperture 25 * and that portion of apertures 30 in registry therewith. 15 ' therein. What is claimed and desired to be secured by United Since, as aforesaid, control band 28 will be adjusted States Letters Patent is: ’ ‘' about projection 22 so that arsuf?cient portion of aper 1. Control mechanism 'for regulating the supply of air ' tures 30, 32 and 34 will be in registry with apertures 23, 26 and 27 to permit delivery "of that quantity of air 7 to a combustion chamber comprising a blower for deliv : stoichiometrically necessary to support combustion in the 20. ering air to said combustion chamber, a housing for said blower having an outlet opening and a side inlet opening, ’ combustion chamber, the provision at this stage of opera tion of supplemental air entry port (aperture 25) will I a cup-shapedmember rigid with said housing and having -a plurality of peripheral openings, the combined area of permit the delivery to the combustion chamber of suf? ‘ cient additional air to assure clean combustion during the . 7' said openings being in excess of that necessary to permit . starting cycle. This condition will persist until the tem 25? delivery by said blower of a sufficient quantity of air to support normal combustion, a band vadjustably encircling " perature in the combustion chamber reaches a predeter said opening for regulating the e?ective size of said open ' mined point, at which time thermostat 52. will open the ' ings, a solenoid carried by said housing having an arma 1 normally closed switch 50, de-energizing solenoid 40 and 1 ture movable radially of said cup-shaped member op '44to be urged into its ‘normally spring-biassed position 30' posite, certain of said openings, said armature being - biased toward said cup-shaped member, an ,arcuate shield ; ‘against and covering aperture 25 in projection 22. having essentially the same radius as the wall of said cup ‘Inthe vforegoing manner, clean and e?icient combus - permitting armature 25 and its associated arcuate shield ' shaped. member carried’ by the’ inner end-of said armature tion. is achieved not only at the beginning of the combus 5tion.cycle, when the combustion chamber is cold,.but, . - and adapted to normally close.v certain of said openings, -. and control means operative to energize said solenoid to - throughout the combustion cycle, even after the tem failure which impairs the operation of the solenoid and .retract'said armature and said shield to uncover certain of said openings at the beginning of each combustion cycle and to thereafter de-energize said solenoid; 2. The control apparatus according to claim 1 wherein said control means comprises a thermostat, responsive to : associated mechanisms will only serve to restore the sys . term to conventional operation, in which case only normal ~ the combustion chamber temperature and operative to ‘ de-energize said solenoid When the temperature in said air requirements will be satis?ed, and Will not impair the combustion chamberhasjrisen to a predetermined level. perature in the combustion chamber has risen to the point’where no excess air is required. lFurthermorqsince . the‘ air supplemental inlet (aperture 25) is open only : when solenoid 40 is energized, a mechanical or electrical 3. The controlmechanism according to claim 1 where operation of the system as a whole or produce danger in said control means comprises a temperature ‘sensitive - ous combustion conditions as did numerous prior art de . vices under similar conditions. 7 The invention may be embodied in other speci?c forms . > 1 - without departing from the spirit or essential character istics thereof. For example, in lieu of thermostat 52, an automatic timer, of a type Well known in the art, may be used to open switch ‘50 and to de-energize solenoid 40 at a predetermined time after the start of the combustion ,. cycle corresponding approximately to the time at which a the combustion chamber will have been‘ brought to a ' temperature at which no additional air is required to sup - port e?icient combustion' In practice, a time of 60 to 90 seconds has been found to be adequate under average ’ device etfective to de-energize said solenoid when said i combustion chamber attains a predetermined tempera » turre- . . References Cited in the ?le of this patent UNITED STATES PATENTS ‘1,895,701- 7 Brown _______________ __ Jan. 31, 1933 2,067,446 Good ________ __, _____ __ Jan. 12, 1937 r 2,218,895 , Selig ________________ ._ Oct. 22, 1940 2,224,705 Stringer ________ __;_____ Dec. 10, 1940 2,465,125 1,503,411 Schulz _____________ __ Mar. 22, 1949 Trumpa _____________ __ Ju1y15, 1952 '