CA1102901A - Energy saving flue damper - Google Patents
Energy saving flue damperInfo
- Publication number
- CA1102901A CA1102901A CA346,690A CA346690A CA1102901A CA 1102901 A CA1102901 A CA 1102901A CA 346690 A CA346690 A CA 346690A CA 1102901 A CA1102901 A CA 1102901A
- Authority
- CA
- Canada
- Prior art keywords
- furnace
- damper
- vane
- open
- close
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N3/00—Regulating air supply or draught
- F23N3/08—Regulating air supply or draught by power-assisted systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2235/00—Valves, nozzles or pumps
- F23N2235/02—Air or combustion gas valves or dampers
- F23N2235/04—Air or combustion gas valves or dampers in stacks
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2235/00—Valves, nozzles or pumps
- F23N2235/02—Air or combustion gas valves or dampers
- F23N2235/10—Air or combustion gas valves or dampers power assisted, e.g. using electric motors
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Regulation And Control Of Combustion (AREA)
- Control Of Combustion (AREA)
Abstract
TITLE
ENERGY SAVING FLUE DAMPER
INVENTORS
Terrence J. MASSE and Fouad BARSOUM
ABSTRACT
Disclosed is a flue damper mechanically driven through a sensor control to change the physical position of a damper within a flue associated with a furnace or other combustion device. By means, after the demand for ignition of the furnace, the flue damper is rotated slowly into the full open position whereupon ignition of the furnace is permitted. After the demand has been satisfied, the ignition is ceased and at a predetermined time thereafter the damper is slowly moved to the closed position whereby to inhibit completely, in the cases of oil fired devices, and to a substantial degree (a maximum of 90%), in gas fired devices, the orifice size of the exhaust flue thereby preserving the residual heat within the boiler or fire box which would otherwise escape through the flue into the atmosphere.
Such device decreases, in excess of 15%, the amount of energy consumed by reducing the cool-down effects of the fire box or boiler. The device also stops migration of warm air from the building through the fire box into the flue and its escape into the atmosphere. The latter problem is really more severe in water retaining boilers (hot water heating) and particularly so, where, the heated environment or building is controlled by so called "zone" techniques, wherein, by the control mechanism of the furnace the boiler is maintained within a predetermined range of temperatures, and the thermostats which control the heating into the various zones of the premises call on and off heat by activating a circulation pump.
ENERGY SAVING FLUE DAMPER
INVENTORS
Terrence J. MASSE and Fouad BARSOUM
ABSTRACT
Disclosed is a flue damper mechanically driven through a sensor control to change the physical position of a damper within a flue associated with a furnace or other combustion device. By means, after the demand for ignition of the furnace, the flue damper is rotated slowly into the full open position whereupon ignition of the furnace is permitted. After the demand has been satisfied, the ignition is ceased and at a predetermined time thereafter the damper is slowly moved to the closed position whereby to inhibit completely, in the cases of oil fired devices, and to a substantial degree (a maximum of 90%), in gas fired devices, the orifice size of the exhaust flue thereby preserving the residual heat within the boiler or fire box which would otherwise escape through the flue into the atmosphere.
Such device decreases, in excess of 15%, the amount of energy consumed by reducing the cool-down effects of the fire box or boiler. The device also stops migration of warm air from the building through the fire box into the flue and its escape into the atmosphere. The latter problem is really more severe in water retaining boilers (hot water heating) and particularly so, where, the heated environment or building is controlled by so called "zone" techniques, wherein, by the control mechanism of the furnace the boiler is maintained within a predetermined range of temperatures, and the thermostats which control the heating into the various zones of the premises call on and off heat by activating a circulation pump.
Description
This device relates to a damper mechanism for opening and closing the orifice size of an exhaus-t flue associated with a heating device such as a furnace, whether gas or oil fired.
There are a number of automatic flue dampers located in the vent stacX for commerical or household furnaces or other apparatus which are designed to close the vent stack during times when combustion within the furnace does not occur, and to open during times when the combustion lG is occuring in the apparatus. Normally, the open position is controlled by a damper spring. In case of default of electric energy the damper itself is moved to its open from closed position; otherwise, by a direct current solenoid associatedly connected to interface with the temperature sensing device which operates the vent - to close it.
Such device moves, quickly, the damper from its open to close position as a result of tha solenoid action and this is not desirable on at least two counts; firstly, extra associated noise with the damper reaching its limit position from its closed to open or open to the closed position, and secondly, the increased mechanical structure necessary in order to stop the inertia of the quick moving damper.
In another automatic stack damper an electric motor is used to rotate the damper within the stack from its open to its closed position and from the closed to its open position either with or without a bias means that operates the vent. Such device is clearly indicated in U,S.A. Patent #4,039,1~3, entitled AUTOMATIC STACK DAMPER to Seymour Frankel, issued 2 August 1977. It suffers from a number of disadvantages which include the re~uirement that the motor 3~
operated vent be connected to a thermal sensing device such as a thermostat located in the vent. It is the vent thermostat which activates and deactivates the electric motor associated with the Frankel device. Thus, the response of the damper is immediate upon the demand of the thermostate to call heat and at shut-ofE period. The requirement of Frankel causes the damper to shut when the thermostat, which senses the temperature in the room be heated, goes off only after, the thermo sensor which is physcially located in the exhaust flue of the furnace, crosses below a cool-down threshold temperature which in most instances is fixed at 400F, approximately 170C.
Particulàrly, an oil fired furnace, where the oil fired furnace is not "tuned" and incomplete combustion normally takes place, soot or carbon particles, are generated by the fire of the oil fired furnace, and move out into the exhaust flue and normally, because they also contain residual oil particles thereon, adhere to the flue.
This causes the temperature sensor in the flue of Frankel to be coated with temperature insulating caxbon particles.
E~ënce, the sensitivity of the sensor may become immune due to the carbon particle coating, in which case, the flue temperature is substantially higher than the ~00F minimum threshold and this cause~ improper operation of the Frankel device.
In instances where the ignition fuel is oil, there is a tendency therefore to prematurely close the damper while still hot escaping flue gases emanate from the fire box since there i8 still oil in the fire box. Hence, carbon monoxide has a tendency to dangerously accumulate.
Further, such de~ice~, because they operate to , close after a fairly long sustained period of time, their ability to preserve the temperature in the fire box, or more accurately in the boiler of the furnace is decreased because of the extremely long period of time that elapses after de-ignition of the furnace and closing of the vent as will hereinafter be noted.
Although, in one sense, the Frankel thermo~sensor in the exhaust flue may be perceived as a time delay mechanism, this is inaccurate since the temperature sensor creates an apparent time delay whose elapsed time is variable and unpredicatable. This is unacceptable from two divergent points of viewî firstly, the vent may be closed .
too soon whereupon dangerous flue gases are trapped in the furnace fire box7 or secondly, the vent may not close soon enough whereupon great heat loss escapes up the exhaust flue between the duration of de-ignition of the furnace and the closing off of the vent. Lack of energy preservation after de-ignition of the furnace is highly significant, in the latter case and may even result in undisclosed inutility in such device. The latter aspect becomes even more acute when there is a large~cross-sectional area of the flue vent and with a greater height of the flue stack since, as those skilled in the art will know, a greater volume of air passes through a vent stack because of greater draw when the cross-sectional area o~ the verlt stack is larger and its height is higher.
~evices, such as FranXel, in Canada have been banned by the Canadian Standards Association precisely for the reasons hereinbefore enumerated.
The present invention overcomes the major failing of Frankel by having a time dependant or time elapse delay 3~
system immune from temperature and other factors, 50 that the hea-~ing cycle ignition and de-ignition points are precisely maintained. Also a synchronous motor is provided for slowly moving the vent from its open to closed position.
The present invention therefore contemplates an improvement to a heatlng system that includes a furnace for generating heat, and that passes exhaust by-products up a venting stack, the furnace having a furnace control circuit to turn off and on the furnace, the improvement comprising:
(a) a damper having a pivoting vane in said venting stack, the vane pivoting between an opened and a closed position;
(b) an actutator attached to the pivoting vane for pivoting said vane to the open and to the closed positions, said actuator including;
(i) a synchronous motor coupled to a sha~t and to said vane for pivoting said vane;
(ii) a time dependant delay means including first switch means for making electrical connection with the motor whereby to energize the motor into rotation whereby the vane rotates;
(iii) second switch means for making electrical contact and adapted to be connected in series ~ith the furnace control circuit and to energize the furnace control circuit when the second switch means is closed so as to 3~ cause the furnace to go on;
(iv) means carried by the shaft for closing the second switch means when the shaft is at a predetermined relative position;
(v) relay means including first and second contact pairs, the relay means responsive to and adapted for serial connection to a thermostat whereby on closing of the thermostat, in response to the minimum ambient temperature selected, the relay means is energized to open one of said contact pairs and to close the other of said contact ~ !
pairs, the first said contact pair in series with the motor whereby to de-energize the motor whereupon the vent rotates open and when fully open means (iv) closes the switch means I
.~ Il (iii) whereby the furnace control ~ circuit is closed and the furnace ~ turns on, the second of said contact pairs being:in series withlsaid second ; switch means and the furnace control circuit.
- , This~invention al90 contemplates an improved method of pre~erving heat within an environment that utilizes a furnace for generating heat, whether by gas or oil fired b~rner, and that: passes.as exhaust, by-products, up a vent~ng stack the furnace having a control circult ~ : which turns it off, the improved method including the steps o~
(a) positioning, in the venting stack, in close ' ~ - 6 proximity ko the furnace a damper having an operative pivot.ing vane therein for opening and closing the cross-sectional area of the damper and hence, the venting stack;
(b) operating the damper to close the venting stack after a predetermined time when the furnace is not consuming fuel to create heat;
(c) sensing the ambient temperature of an environment to be heated and establishing therefore, a maximum and minimum ambient temperature;
(d) activating the damper to open when the minimum ambient temperature is sensed by said sensing step;
~e) igniting the combustionable fuels in said furnace so that said furnace creates heat and conveying the heat to said environment;
(f) closing the supplv of fuel to the urnace when the maximum ambient temperature is 20 :~ reached; and : (g) waiting a predetsrmined period, after step e) and~then closi~ng the vent in the exhaust flue~stack thereby preservlng the remaining : heat contained ~ln~the furnace for distr:ibu-tion to~the~env1ronment.
Ihe invention will. now be described by way of example wi h reference to the accompanying drawings in :
: which~
:, j :
~ Figure 1 i8 a perSpeCtlVe; vieW of the mechanical 30 ~ device.
: Figures 2 and 3 are side elevations respectively, ~ ~, .
of the device of Figure 1.
Figure 4 is a location diagram of the vent in use.
Figure 5 is a top view of a Eull closure ven-t preferred for oil fired application, as is shown in side elevations in Figures 2 and 3.
Figure 6 is a.n electrical ci.rcuit diagram.
Figure 7 ls an alternative embodiment of a damper, top view as in Fiyure 2, but possessing a vane of reduced area to show continuous venting in the closed position, as preferred for gas fired application~
Referring, in part to all the drawings, the principal embodiments of ~he invéntion as now preferably , 1~
contemplated by th~ inventor include~ in surnmary, an improved heating jsystem that includes a furnace, referred to as referenice 30,~ for generating heat, whether as a gas fired or oiljfired o~. otherwise fired unit, and that passes exhaust bylproducts as a result of combustion up a venting stack, refèrenced,l32. Th furnace has a furnace control , circuit (not shown), but those skilled in the art will be famillar with it,;to turn~the furnace off and on; the mprovement comprises,~a damper, generally illustrated as 1, having a pivotlng;vane, eîther 15 or 15', in said venting stack.2, the;vane~pivoting: between a closed (the solid po~ition in ~igure~l) and;an open position tthe fanthom position in Figure l); an acutator attached to the pivoting vane for pivoting said vane to the open or to the closed positions. The said actuator includes a synchronous motor 6 coupled to a sha~t 7'and to said vane 15 for pivoting said vane; a time dependant delay means 9 including a first switch means, 9'' for making electrical connection with the motor 6 whereby to energize the motor 6 into rotation . - 8 . .
whereby the vane 15 rotates. A second switch means referenced 11 for making electrical contact and adapted to be connected in series with the furnace control circuit and to energize the furnace control clrcuit when the second switch means is closed so as to cause the furnace to go on.
Means (the projection of lever arm 4) carried by the shaft 7 for closing the second switch means when the shaft 7 and hence, lever 4 is in a predetermined position. A relay means 19 includes first and second contact pairs as illustrated, the relay means 19 responsive to and adapted for serial connection to a thermostat, referenced 43, whereby on closing of the thermostat, in response to the minimum ambient temperature selected for the heated environment, the relay means 9 is energi~ed to open one of said contact pairs and to close the other of said contact pairs, the first of said contact pairs connected in series to the synchronous motor 6 whereby to de-energize the motor whereupon the vent 15 rotates open under the force of a biasing spring 14, and when fully open the projection of shaft 4 closes the switch means 11, which in the preferred embodiment is a micro-swi~ch. The furnace control circuit i5 thus closed and the furnace 30 turns on, the second of said contact~paixs being connected in series with said ~econd switch means 11 and the furnace control circui~.
Af er the thermostat reaches and senses the maximum ambien~ temperature selected, it opens and this opens the relay mean~ which reverses the two contact pairs which, in one circuit, immediately opens the furnace control circuit so that the furnace is turned off, and in the other circuit energizes the time dependant dela~ means 9 whereupon after the predetermined delay of time, the coil 9' thereof, :
causes the switch 9'' to close activating the synchronous motor 6 into the counter-clockwise direction to close the vane 15.
Referring to Figures l and 4 a damper assembly 1 is positioned in the exhaust flue venting stream downstream from a furnace or other heating device 30 to which it is attached. More particularly, the damper l is positioned in -the vent stack 32 just downstream of a barometric damper 33 that i5 disposed between furnace 30 and damper 1.
Referring to Figures 1 through 5 the damper assembly 1 includes outer sheet metal tubing 2, preferably of aluminized steel to resist rust and to withstand 1200F
(650C) and a diametrically positioned shaft 7 which projects into outside bearing members 16 mounted in the walls of the tubing 2. A circular sheet member 15 is affixed to the shaft 7 as a vane and is pivoted by the rotational position of the shaft whereby to open and close the internal diameter and to change the effective cross sectional area of the sleeve 2. One end of the damper shaft 7 extends to a coupling 8 which attaches itself, as by conventional means, to a synchronous motor 6 that is secured by bolts 6I through standoffs or spacers 6" onto a circumferential housing 20. Through coupling 8 is mounted a lever arm 4 which acts as a lever that can mechanically move or pivot the vane 15 from open to closed or closed to open position. 1~0 vane is shown in Figure 1, in fanthom, in a more open position than in solid and the position of the lever arm 4 in the fanthom position is that which correspondingly represents the more open position ln fanthom. A return coil spring 14 embraces the lever 4 and biasingly urges the shaft 7 counterclockwise, when referring electric synch~onous motor 6 i5 energized, it urges against to Fîgure 2, so that the vane is fully opened. When the the bias of the spring 14 to close the vane and to hold the vane in -the closed position, that of Figure 5.
Referring to the electrical circuit diagram Figure 6 it includes a terminal block 35 for the interconnection of various wires and circuits associated with the time delay mechanism 9 the relay mechanism la housing first and second contact pairs and other switches. Wire pair 40 is to be connected to a 24 volt transformer which supplies the energy to the complete system. Wire pair 42 interconnect to a room thermostat 43 which, when closed, calls for heat. The heat cycle commences. In reality the thermostat 43 eneryizes relay 18 to make contacts of the first contact pair and break the contacts of the second contact pair. Wire pair 41 is interconnected to the heating device 30 and for example is connected directly to either a gas solenoid which operates the gas valve of a gas fired furnace, or in the case of an oil burner, to the electrical motor of the oil ~O burner of an oil fired furnace. Hence, this pair 41 is connected to the furnace on/off control circuit. Access to this circuit i9 obtained by disconnecting the boiler or furnacé high limit control and placing this wire pair in series therewith so that the boiler or furnace is activated ON when the micro-switch 11 closes, From the terminals of the terminal block 35, the wire pair 41 is in series with the micro-switch 11 and with the second contact pair (normally open) of relay 18. When relay 18 is energized this second contact pair is closed.
Assuming, now, that the motor 6 is energiæed to ho:Ld the vane 15 in the closed position of Figure 5, in that instance, the time delay relay 9 will be closed a~ in the solid position of Figure 1. When the room thermostat 43 closes and the call of heat therefore is made, control relay 18 is energized thereby and the contacts of relay 18 are therefore moved from the solid to the fanthom position, of both contact pairs. Contacts of the time delay 9 are opened ~rom the fanthom position to the solid position and the motor 6 is de~energizedO On de-energization, the return coil spring 14 moves the vane 15 to the open position, the fanthom position of Figure 1 and when the open position is fully achieved, (see Figure 3) the projection of the lever 4 through the shaft 7 strikes the leverage arm 49 of the micro-switch 11 to close the same thereby completing the furnace control circuit through the second contact pair of relay 18. The furnace goes on and heating begins.
When the heat level required is reached, the thermostat 43 opens thereby de-energizing the relay coil 18 moving the contact pairs thereof into the solid position shown in Figure 6. The furnace goes off since the second contact pair of relay 18 is opened thereby. The time delay coil 9' is energized but will not activate the switch thereof until the given time delay period of the time delay switch is reached; typ1cally two minutes. When the time delay period ha~ elapsed,~the switch 9'' closes and the synchronous motor 6 is activated to return the vane 15 (15') to the closed position. A typical time delay mechanism preferred, is a~mechanical~time delay mechanism that is preferably temper~ture compensated. That manufactured by the Paragon Electric Company, a division of AMF of the United States of America with a two minute delay, namely, model number #903 mechanical time delay mechanism is satisfactory.
For servicing or for other reasons where it is desirable to override the electrical function of the vent as hereinbefore described and hence to cause the vane 15 to be located and fixed in the open position, the lever arm 4 may be moved by hand from the solid position to the fan~hom posi-tion, as shown in E`igure 1, and the dead bolt 50 indexed -there to cross and to hold the lever arm 4 in the vertical fanthom position. This mechanical override permits maintainance of the device 1 and the furnace while at the same time, since the longitudinal axis of the lever arrn is mounted in the same plane as that of the vane 15, the lever arm 4 is a visual indicator of the actual position of the vane 15 in the damper 1.
In order to keep the actuator cornponent as "cool"
as possible and thereby to eliminate the transfer of heat from the stack 2 to the hou~ing 20 and its cover 20' they are mounted on an extension bracket 25 and if desirable, the extention~bracket 25 may be composed of material other than metal so that to inhibit, as much as possible, the conductlon o~ heat from the sleeve to the housing 20 and its components. Mounting of the bracket 25 to the stack 2 is simplictica1ly done by sheet metal screws, shown in Figur~ 1 but not r~ferenced.
ReferrLng to Figure 5 and another embodiment of vane 15' the ~ame has its~peripheral margins parallel and truncated so that the vane~15' displays an area as when in the closed position of Figure S of about 90% of the actual cross sectional area of~the sleeve 2. This, leaves, on the two diametrically oppo~ed marginal sides of the vane 15' space area 19 for flue gases to pass by the vane 15' even when i.n the fully closed position. This eature is desirable when the damper assembly 1 is used in gas fired furnaces, with pilot lights, so as to not inhibit the flow of exhaust bi-products generated in the fire box by the pilot light during furnace de-ignition.
, , ,
There are a number of automatic flue dampers located in the vent stacX for commerical or household furnaces or other apparatus which are designed to close the vent stack during times when combustion within the furnace does not occur, and to open during times when the combustion lG is occuring in the apparatus. Normally, the open position is controlled by a damper spring. In case of default of electric energy the damper itself is moved to its open from closed position; otherwise, by a direct current solenoid associatedly connected to interface with the temperature sensing device which operates the vent - to close it.
Such device moves, quickly, the damper from its open to close position as a result of tha solenoid action and this is not desirable on at least two counts; firstly, extra associated noise with the damper reaching its limit position from its closed to open or open to the closed position, and secondly, the increased mechanical structure necessary in order to stop the inertia of the quick moving damper.
In another automatic stack damper an electric motor is used to rotate the damper within the stack from its open to its closed position and from the closed to its open position either with or without a bias means that operates the vent. Such device is clearly indicated in U,S.A. Patent #4,039,1~3, entitled AUTOMATIC STACK DAMPER to Seymour Frankel, issued 2 August 1977. It suffers from a number of disadvantages which include the re~uirement that the motor 3~
operated vent be connected to a thermal sensing device such as a thermostat located in the vent. It is the vent thermostat which activates and deactivates the electric motor associated with the Frankel device. Thus, the response of the damper is immediate upon the demand of the thermostate to call heat and at shut-ofE period. The requirement of Frankel causes the damper to shut when the thermostat, which senses the temperature in the room be heated, goes off only after, the thermo sensor which is physcially located in the exhaust flue of the furnace, crosses below a cool-down threshold temperature which in most instances is fixed at 400F, approximately 170C.
Particulàrly, an oil fired furnace, where the oil fired furnace is not "tuned" and incomplete combustion normally takes place, soot or carbon particles, are generated by the fire of the oil fired furnace, and move out into the exhaust flue and normally, because they also contain residual oil particles thereon, adhere to the flue.
This causes the temperature sensor in the flue of Frankel to be coated with temperature insulating caxbon particles.
E~ënce, the sensitivity of the sensor may become immune due to the carbon particle coating, in which case, the flue temperature is substantially higher than the ~00F minimum threshold and this cause~ improper operation of the Frankel device.
In instances where the ignition fuel is oil, there is a tendency therefore to prematurely close the damper while still hot escaping flue gases emanate from the fire box since there i8 still oil in the fire box. Hence, carbon monoxide has a tendency to dangerously accumulate.
Further, such de~ice~, because they operate to , close after a fairly long sustained period of time, their ability to preserve the temperature in the fire box, or more accurately in the boiler of the furnace is decreased because of the extremely long period of time that elapses after de-ignition of the furnace and closing of the vent as will hereinafter be noted.
Although, in one sense, the Frankel thermo~sensor in the exhaust flue may be perceived as a time delay mechanism, this is inaccurate since the temperature sensor creates an apparent time delay whose elapsed time is variable and unpredicatable. This is unacceptable from two divergent points of viewî firstly, the vent may be closed .
too soon whereupon dangerous flue gases are trapped in the furnace fire box7 or secondly, the vent may not close soon enough whereupon great heat loss escapes up the exhaust flue between the duration of de-ignition of the furnace and the closing off of the vent. Lack of energy preservation after de-ignition of the furnace is highly significant, in the latter case and may even result in undisclosed inutility in such device. The latter aspect becomes even more acute when there is a large~cross-sectional area of the flue vent and with a greater height of the flue stack since, as those skilled in the art will know, a greater volume of air passes through a vent stack because of greater draw when the cross-sectional area o~ the verlt stack is larger and its height is higher.
~evices, such as FranXel, in Canada have been banned by the Canadian Standards Association precisely for the reasons hereinbefore enumerated.
The present invention overcomes the major failing of Frankel by having a time dependant or time elapse delay 3~
system immune from temperature and other factors, 50 that the hea-~ing cycle ignition and de-ignition points are precisely maintained. Also a synchronous motor is provided for slowly moving the vent from its open to closed position.
The present invention therefore contemplates an improvement to a heatlng system that includes a furnace for generating heat, and that passes exhaust by-products up a venting stack, the furnace having a furnace control circuit to turn off and on the furnace, the improvement comprising:
(a) a damper having a pivoting vane in said venting stack, the vane pivoting between an opened and a closed position;
(b) an actutator attached to the pivoting vane for pivoting said vane to the open and to the closed positions, said actuator including;
(i) a synchronous motor coupled to a sha~t and to said vane for pivoting said vane;
(ii) a time dependant delay means including first switch means for making electrical connection with the motor whereby to energize the motor into rotation whereby the vane rotates;
(iii) second switch means for making electrical contact and adapted to be connected in series ~ith the furnace control circuit and to energize the furnace control circuit when the second switch means is closed so as to 3~ cause the furnace to go on;
(iv) means carried by the shaft for closing the second switch means when the shaft is at a predetermined relative position;
(v) relay means including first and second contact pairs, the relay means responsive to and adapted for serial connection to a thermostat whereby on closing of the thermostat, in response to the minimum ambient temperature selected, the relay means is energized to open one of said contact pairs and to close the other of said contact ~ !
pairs, the first said contact pair in series with the motor whereby to de-energize the motor whereupon the vent rotates open and when fully open means (iv) closes the switch means I
.~ Il (iii) whereby the furnace control ~ circuit is closed and the furnace ~ turns on, the second of said contact pairs being:in series withlsaid second ; switch means and the furnace control circuit.
- , This~invention al90 contemplates an improved method of pre~erving heat within an environment that utilizes a furnace for generating heat, whether by gas or oil fired b~rner, and that: passes.as exhaust, by-products, up a vent~ng stack the furnace having a control circult ~ : which turns it off, the improved method including the steps o~
(a) positioning, in the venting stack, in close ' ~ - 6 proximity ko the furnace a damper having an operative pivot.ing vane therein for opening and closing the cross-sectional area of the damper and hence, the venting stack;
(b) operating the damper to close the venting stack after a predetermined time when the furnace is not consuming fuel to create heat;
(c) sensing the ambient temperature of an environment to be heated and establishing therefore, a maximum and minimum ambient temperature;
(d) activating the damper to open when the minimum ambient temperature is sensed by said sensing step;
~e) igniting the combustionable fuels in said furnace so that said furnace creates heat and conveying the heat to said environment;
(f) closing the supplv of fuel to the urnace when the maximum ambient temperature is 20 :~ reached; and : (g) waiting a predetsrmined period, after step e) and~then closi~ng the vent in the exhaust flue~stack thereby preservlng the remaining : heat contained ~ln~the furnace for distr:ibu-tion to~the~env1ronment.
Ihe invention will. now be described by way of example wi h reference to the accompanying drawings in :
: which~
:, j :
~ Figure 1 i8 a perSpeCtlVe; vieW of the mechanical 30 ~ device.
: Figures 2 and 3 are side elevations respectively, ~ ~, .
of the device of Figure 1.
Figure 4 is a location diagram of the vent in use.
Figure 5 is a top view of a Eull closure ven-t preferred for oil fired application, as is shown in side elevations in Figures 2 and 3.
Figure 6 is a.n electrical ci.rcuit diagram.
Figure 7 ls an alternative embodiment of a damper, top view as in Fiyure 2, but possessing a vane of reduced area to show continuous venting in the closed position, as preferred for gas fired application~
Referring, in part to all the drawings, the principal embodiments of ~he invéntion as now preferably , 1~
contemplated by th~ inventor include~ in surnmary, an improved heating jsystem that includes a furnace, referred to as referenice 30,~ for generating heat, whether as a gas fired or oiljfired o~. otherwise fired unit, and that passes exhaust bylproducts as a result of combustion up a venting stack, refèrenced,l32. Th furnace has a furnace control , circuit (not shown), but those skilled in the art will be famillar with it,;to turn~the furnace off and on; the mprovement comprises,~a damper, generally illustrated as 1, having a pivotlng;vane, eîther 15 or 15', in said venting stack.2, the;vane~pivoting: between a closed (the solid po~ition in ~igure~l) and;an open position tthe fanthom position in Figure l); an acutator attached to the pivoting vane for pivoting said vane to the open or to the closed positions. The said actuator includes a synchronous motor 6 coupled to a sha~t 7'and to said vane 15 for pivoting said vane; a time dependant delay means 9 including a first switch means, 9'' for making electrical connection with the motor 6 whereby to energize the motor 6 into rotation . - 8 . .
whereby the vane 15 rotates. A second switch means referenced 11 for making electrical contact and adapted to be connected in series with the furnace control circuit and to energize the furnace control clrcuit when the second switch means is closed so as to cause the furnace to go on.
Means (the projection of lever arm 4) carried by the shaft 7 for closing the second switch means when the shaft 7 and hence, lever 4 is in a predetermined position. A relay means 19 includes first and second contact pairs as illustrated, the relay means 19 responsive to and adapted for serial connection to a thermostat, referenced 43, whereby on closing of the thermostat, in response to the minimum ambient temperature selected for the heated environment, the relay means 9 is energi~ed to open one of said contact pairs and to close the other of said contact pairs, the first of said contact pairs connected in series to the synchronous motor 6 whereby to de-energize the motor whereupon the vent 15 rotates open under the force of a biasing spring 14, and when fully open the projection of shaft 4 closes the switch means 11, which in the preferred embodiment is a micro-swi~ch. The furnace control circuit i5 thus closed and the furnace 30 turns on, the second of said contact~paixs being connected in series with said ~econd switch means 11 and the furnace control circui~.
Af er the thermostat reaches and senses the maximum ambien~ temperature selected, it opens and this opens the relay mean~ which reverses the two contact pairs which, in one circuit, immediately opens the furnace control circuit so that the furnace is turned off, and in the other circuit energizes the time dependant dela~ means 9 whereupon after the predetermined delay of time, the coil 9' thereof, :
causes the switch 9'' to close activating the synchronous motor 6 into the counter-clockwise direction to close the vane 15.
Referring to Figures l and 4 a damper assembly 1 is positioned in the exhaust flue venting stream downstream from a furnace or other heating device 30 to which it is attached. More particularly, the damper l is positioned in -the vent stack 32 just downstream of a barometric damper 33 that i5 disposed between furnace 30 and damper 1.
Referring to Figures 1 through 5 the damper assembly 1 includes outer sheet metal tubing 2, preferably of aluminized steel to resist rust and to withstand 1200F
(650C) and a diametrically positioned shaft 7 which projects into outside bearing members 16 mounted in the walls of the tubing 2. A circular sheet member 15 is affixed to the shaft 7 as a vane and is pivoted by the rotational position of the shaft whereby to open and close the internal diameter and to change the effective cross sectional area of the sleeve 2. One end of the damper shaft 7 extends to a coupling 8 which attaches itself, as by conventional means, to a synchronous motor 6 that is secured by bolts 6I through standoffs or spacers 6" onto a circumferential housing 20. Through coupling 8 is mounted a lever arm 4 which acts as a lever that can mechanically move or pivot the vane 15 from open to closed or closed to open position. 1~0 vane is shown in Figure 1, in fanthom, in a more open position than in solid and the position of the lever arm 4 in the fanthom position is that which correspondingly represents the more open position ln fanthom. A return coil spring 14 embraces the lever 4 and biasingly urges the shaft 7 counterclockwise, when referring electric synch~onous motor 6 i5 energized, it urges against to Fîgure 2, so that the vane is fully opened. When the the bias of the spring 14 to close the vane and to hold the vane in -the closed position, that of Figure 5.
Referring to the electrical circuit diagram Figure 6 it includes a terminal block 35 for the interconnection of various wires and circuits associated with the time delay mechanism 9 the relay mechanism la housing first and second contact pairs and other switches. Wire pair 40 is to be connected to a 24 volt transformer which supplies the energy to the complete system. Wire pair 42 interconnect to a room thermostat 43 which, when closed, calls for heat. The heat cycle commences. In reality the thermostat 43 eneryizes relay 18 to make contacts of the first contact pair and break the contacts of the second contact pair. Wire pair 41 is interconnected to the heating device 30 and for example is connected directly to either a gas solenoid which operates the gas valve of a gas fired furnace, or in the case of an oil burner, to the electrical motor of the oil ~O burner of an oil fired furnace. Hence, this pair 41 is connected to the furnace on/off control circuit. Access to this circuit i9 obtained by disconnecting the boiler or furnacé high limit control and placing this wire pair in series therewith so that the boiler or furnace is activated ON when the micro-switch 11 closes, From the terminals of the terminal block 35, the wire pair 41 is in series with the micro-switch 11 and with the second contact pair (normally open) of relay 18. When relay 18 is energized this second contact pair is closed.
Assuming, now, that the motor 6 is energiæed to ho:Ld the vane 15 in the closed position of Figure 5, in that instance, the time delay relay 9 will be closed a~ in the solid position of Figure 1. When the room thermostat 43 closes and the call of heat therefore is made, control relay 18 is energized thereby and the contacts of relay 18 are therefore moved from the solid to the fanthom position, of both contact pairs. Contacts of the time delay 9 are opened ~rom the fanthom position to the solid position and the motor 6 is de~energizedO On de-energization, the return coil spring 14 moves the vane 15 to the open position, the fanthom position of Figure 1 and when the open position is fully achieved, (see Figure 3) the projection of the lever 4 through the shaft 7 strikes the leverage arm 49 of the micro-switch 11 to close the same thereby completing the furnace control circuit through the second contact pair of relay 18. The furnace goes on and heating begins.
When the heat level required is reached, the thermostat 43 opens thereby de-energizing the relay coil 18 moving the contact pairs thereof into the solid position shown in Figure 6. The furnace goes off since the second contact pair of relay 18 is opened thereby. The time delay coil 9' is energized but will not activate the switch thereof until the given time delay period of the time delay switch is reached; typ1cally two minutes. When the time delay period ha~ elapsed,~the switch 9'' closes and the synchronous motor 6 is activated to return the vane 15 (15') to the closed position. A typical time delay mechanism preferred, is a~mechanical~time delay mechanism that is preferably temper~ture compensated. That manufactured by the Paragon Electric Company, a division of AMF of the United States of America with a two minute delay, namely, model number #903 mechanical time delay mechanism is satisfactory.
For servicing or for other reasons where it is desirable to override the electrical function of the vent as hereinbefore described and hence to cause the vane 15 to be located and fixed in the open position, the lever arm 4 may be moved by hand from the solid position to the fan~hom posi-tion, as shown in E`igure 1, and the dead bolt 50 indexed -there to cross and to hold the lever arm 4 in the vertical fanthom position. This mechanical override permits maintainance of the device 1 and the furnace while at the same time, since the longitudinal axis of the lever arrn is mounted in the same plane as that of the vane 15, the lever arm 4 is a visual indicator of the actual position of the vane 15 in the damper 1.
In order to keep the actuator cornponent as "cool"
as possible and thereby to eliminate the transfer of heat from the stack 2 to the hou~ing 20 and its cover 20' they are mounted on an extension bracket 25 and if desirable, the extention~bracket 25 may be composed of material other than metal so that to inhibit, as much as possible, the conductlon o~ heat from the sleeve to the housing 20 and its components. Mounting of the bracket 25 to the stack 2 is simplictica1ly done by sheet metal screws, shown in Figur~ 1 but not r~ferenced.
ReferrLng to Figure 5 and another embodiment of vane 15' the ~ame has its~peripheral margins parallel and truncated so that the vane~15' displays an area as when in the closed position of Figure S of about 90% of the actual cross sectional area of~the sleeve 2. This, leaves, on the two diametrically oppo~ed marginal sides of the vane 15' space area 19 for flue gases to pass by the vane 15' even when i.n the fully closed position. This eature is desirable when the damper assembly 1 is used in gas fired furnaces, with pilot lights, so as to not inhibit the flow of exhaust bi-products generated in the fire box by the pilot light during furnace de-ignition.
, , ,
Claims (8)
1. An improvement to a heating system that includes a furnace for generating heat, and that passes exhaust by-products up a venting stack, the furnace having a furnace control circuit to turn off and on the furnace, the improvement comprising:
(a) a damper having a pivoting vane in said venting stack, the vane pivoting between an opened and a closed position;
(b) an actutator attached to the pivoting vane for pivoting said vane to the open and to the closed positions, said actuator including;
(i) a synchronous motor coupled to a shaft and to said vane for pivoting said vane;
(ii) a time dependant delay means including first switch means for making electrical connection with the motor whereby to energize the motor into rotation whereby the vane rotates;
(iii) second switch means for making electrical contact and adapted to be connected in series with the furnace control circuit and to energize the furnace control circuit when the second switch means is closed so as to cause the furnace to go on;
(iv) means carried by the shaft for closing the second switch means when the shaft is at a predetermined relative position;
(v) relay means including first and second contact pairs, the relay means responsive to and adapted for serial connection to a thermostat whereby on closing of the thermostat, in response to the minimum ambient temperature selected, the relay means is energized to open one of said contact pairs and to close the other of said contact pairs, the first said contact pair in series with the motor whereby to de-energize the motor whereupon the vent rotates open and when fully open means (iv) closes the switch means (iii) whereby the furnace control circuit is closed and the furnace turns on, the second of said contact pairs being in series with said second switch means and the furnace control circuit.
(a) a damper having a pivoting vane in said venting stack, the vane pivoting between an opened and a closed position;
(b) an actutator attached to the pivoting vane for pivoting said vane to the open and to the closed positions, said actuator including;
(i) a synchronous motor coupled to a shaft and to said vane for pivoting said vane;
(ii) a time dependant delay means including first switch means for making electrical connection with the motor whereby to energize the motor into rotation whereby the vane rotates;
(iii) second switch means for making electrical contact and adapted to be connected in series with the furnace control circuit and to energize the furnace control circuit when the second switch means is closed so as to cause the furnace to go on;
(iv) means carried by the shaft for closing the second switch means when the shaft is at a predetermined relative position;
(v) relay means including first and second contact pairs, the relay means responsive to and adapted for serial connection to a thermostat whereby on closing of the thermostat, in response to the minimum ambient temperature selected, the relay means is energized to open one of said contact pairs and to close the other of said contact pairs, the first said contact pair in series with the motor whereby to de-energize the motor whereupon the vent rotates open and when fully open means (iv) closes the switch means (iii) whereby the furnace control circuit is closed and the furnace turns on, the second of said contact pairs being in series with said second switch means and the furnace control circuit.
2. The improvement as claimed in claim l including biasing means for holding the pivoting vane open when the motor is de-energized.
3. The improvement as claimed in claim 2 wherein means (iv) is a longitudinal member which is attached to said shaft and is rotated thereby about an axis orthogonal to its own longitudinal axis, one end of said member adapted to strike said switch means and to close it.
4. The improvement as claimed in claim 1 wherein said second switch means is a micro-switch.
5. The improvement as claimed in claims 2, 3 or 4 wherein the thermostat, in response to the maximum ambient temperature, opens and thus deactivates the relay causing the second contact pair to open whereby the furnace control circuit is opened, and to close said first contact pair thereby to activate the time dependent delay means, which after its predetermined time, closes and powers into rotation the synchronous motor so as to rotate the vent to close.
6. The improvement as claimed in claims 2, 3 or 4 wherein the thermostat, in response to the maximum ambient temperature, opens and thus deactivates the relay causing the second contact pair to open whereby the furnace control circuit is opened, and to close said first contact pair thereby to activate the time dependent delay means, which after its predetermined time, closes and powers into rotation the synchronous motor so as to rotate the vent to close and the time dependant delay means closes to activate the motor after only two minutes of activation by the relay means.
7. The improvement as claimed in claims 2, 3 or 4 wherein the thermostat, in response to the maximum ambient temperature, opens and thus deactivates the relay causing the second contact pair to open whereby the furnace control circuit is opened, and to close said first contact pair thereby to activate the time dependent delay means, which after its predetermined time, closes and powers into rotation the synchronous motor so as to rotate the vent to close and the time dependant delay means is a mechanical time delay mechanism.
8. An improved method of preserving heat within an environment that utilizes a furnace for generating heat, whether by gas or oil fired burner, and that passes as exhaust, by-products, up a venting stack the furnace having a control circuit which turns it off, the improved method including the steps of:
(a) positioning, in the venting stack, in close proximity to the furnace a damper having an operative pivoting vane therein for opening and closing the cross-sectional area of the damper and hence, the venting stack and biasing the damper open;
(b) operating the damper to urge against the said biasing and to close the venting stack after a predetermined time when the furnace is not consuming fuel to create heat;
(c) sensing the ambient temperature of an environment to be heated and establishing therefore, a maximum and minimum ambient temperature;
(d) releasing the damper to open under said biasing when the minimum ambient temperature is sensed by said sensing step;
(e) igniting the combustionable fuels in said furnace so that said furnace creates heat and conveying the heat to said environment;
(f) closing the supply of fuel to the furnace when the maximum ambient temperature is reached; and (g) waiting a predetermined period, after step (e) and then repeating step (b).
(a) positioning, in the venting stack, in close proximity to the furnace a damper having an operative pivoting vane therein for opening and closing the cross-sectional area of the damper and hence, the venting stack and biasing the damper open;
(b) operating the damper to urge against the said biasing and to close the venting stack after a predetermined time when the furnace is not consuming fuel to create heat;
(c) sensing the ambient temperature of an environment to be heated and establishing therefore, a maximum and minimum ambient temperature;
(d) releasing the damper to open under said biasing when the minimum ambient temperature is sensed by said sensing step;
(e) igniting the combustionable fuels in said furnace so that said furnace creates heat and conveying the heat to said environment;
(f) closing the supply of fuel to the furnace when the maximum ambient temperature is reached; and (g) waiting a predetermined period, after step (e) and then repeating step (b).
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA346,690A CA1102901A (en) | 1980-02-29 | 1980-02-29 | Energy saving flue damper |
| GB8104456A GB2071878A (en) | 1980-02-29 | 1981-02-12 | Flue damper control system |
| HU81389A HU183336B (en) | 1980-02-29 | 1981-02-18 | Energy spare chimney valve and method for operating same |
| DE19818104594U DE8104594U1 (en) | 1980-02-29 | 1981-02-19 | LIGHTER SLIDER |
| DE19813106085 DE3106085A1 (en) | 1980-02-29 | 1981-02-19 | LIGHTER SLIDER |
| SE8101253A SE8101253L (en) | 1980-02-29 | 1981-02-26 | ROKGANGSSPJELL |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA346,690A CA1102901A (en) | 1980-02-29 | 1980-02-29 | Energy saving flue damper |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1102901A true CA1102901A (en) | 1981-06-09 |
Family
ID=4116358
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA346,690A Expired CA1102901A (en) | 1980-02-29 | 1980-02-29 | Energy saving flue damper |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA1102901A (en) |
| DE (2) | DE8104594U1 (en) |
| GB (1) | GB2071878A (en) |
| HU (1) | HU183336B (en) |
| SE (1) | SE8101253L (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10208953B2 (en) | 2013-01-16 | 2019-02-19 | A. O. Smith Corporation | Modulating burner |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT239531Y1 (en) * | 1995-12-22 | 2001-03-05 | Fime Fab It Motor Elett | SUCTION UNIT FOR GAS BOILERS WITH NATURAL DRAWING, HAVING REDUCED DIMENSIONS WITH LARGE VERSATILITY OF USE |
| US9939175B2 (en) | 2012-10-31 | 2018-04-10 | Rheem Manufacturing Company | Flue damper control algorithm for standing pilot type fuel-fired water heater |
| CN107477230A (en) * | 2017-09-29 | 2017-12-15 | 南通市力沛流体阀业有限公司 | A kind of waterproofing valve protection device of high insulating effect |
-
1980
- 1980-02-29 CA CA346,690A patent/CA1102901A/en not_active Expired
-
1981
- 1981-02-12 GB GB8104456A patent/GB2071878A/en not_active Withdrawn
- 1981-02-18 HU HU81389A patent/HU183336B/en unknown
- 1981-02-19 DE DE19818104594U patent/DE8104594U1/en not_active Expired
- 1981-02-19 DE DE19813106085 patent/DE3106085A1/en not_active Withdrawn
- 1981-02-26 SE SE8101253A patent/SE8101253L/en not_active Application Discontinuation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10208953B2 (en) | 2013-01-16 | 2019-02-19 | A. O. Smith Corporation | Modulating burner |
Also Published As
| Publication number | Publication date |
|---|---|
| SE8101253L (en) | 1981-08-30 |
| DE3106085A1 (en) | 1982-03-25 |
| GB2071878A (en) | 1981-09-23 |
| DE8104594U1 (en) | 1982-04-15 |
| HU183336B (en) | 1984-04-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |