вход по аккаунту


Патент USA US3054452

код для вставки
Sept. 18, 1962
Filed Aug. 15, 1959
5%a%_;é g gzg,
United States Patent 0 " "ice
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
Patented Sept. 18, 1962
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
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
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.
The invention may be embodied in other speci?c forms
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
References Cited in the ?le of this patent
‘1,895,701- 7 Brown _______________ __ Jan. 31, 1933
Good ________ __, _____ __ Jan. 12, 1937
r 2,218,895 ,
Selig ________________ ._ Oct. 22, 1940
Stringer ________ __;_____ Dec. 10, 1940
Schulz _____________ __ Mar. 22, 1949
Trumpa _____________ __ Ju1y15, 1952
Без категории
Размер файла
396 Кб
Пожаловаться на содержимое документа