US3788795A

US3788795A - Pressure operated modulating meter for regulating a flue damper

Info

Publication number: US3788795A
Application number: US00259569A
Authority: US
Inventors: E Zeitlin
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-06-05
Filing date: 1972-06-05
Publication date: 1974-01-29
Anticipated expiration: 1991-01-29

Abstract

A flue draft pressure operated monitoring meter for an electrooptical switching circuit primarily for intermittent regulatory interruption of a current in a circuit to control the direction of rotation of a chimney damper motor to be monitored with a pivotally mounted pointer gauge to intercept the light beam between either of two lamps and photo cell combinations that are connected to said chimney damper reversible motor through a circuitry for maintaining a desired operation setting and indicating lamps to indicate when there is no draft in said chimney, when there is too much draft in said chimney and when the chimney damper remains open.

Description

United States Patent 1 Zeitlin Jan. 29, 1974 [76] Inventor: Edward J. Zeitlin, 115 Fifth Ave.,

Purdys, NY. 10003 [22] Filed: June 5, 1972 [21] Appl. No.: 259,569

Related US. Application Data [63] Continuation-impart of Ser. No. 70,531, Sept. 8,

[52] US. Cl 431/13, 431/20, 236/45, 250/231 R, 126/286 [51] Int. Cl. F23d 5/12 [58] Field of Search 431/13, 16, 19, 20; 250/231 R, 250/231 P; 110/147, 163; 126/286; 318/645;

8/1940 Klinker 431/20 2,932,350 4/1960 Cooper 431/20 2,118,029 5/1938 Boyd 236/26 3,304,553 2/1967 Phillips 250/231 R 3,332,014 7/1967 Orths et a1. 250/231 R Primary Examiner-Carrol1 B. Dority, Jr. Attorney, Agent, or Firm-Howard T. .leandron V [5 7] ABSTRACT A flue draft pressure operated monitoring meter for an electro-optical switching circuit primarily for intermittent regulatory interruption of a current in a circuit to control the direction of rotation of a chimney damper motor to be monitored with a pivotally mounted pointer gauge to intercept the light beam between either of two lamps and photo cell combinations that are connected to said chimney damper reversible motor through a circuitry for maintaining a desired operation setting and indicating lamps to indicate when there is no draft in said chimney, when there is too much draft in said chimney and when the chimney damper remains open.

6 Claims, 5 Drawing Figures PATENTEU JAN29 19H SHEET 1 BF 2 I VENTOR. EDWARDJ. ZEITLIN AGENT PRESSURE OPERATED MODULATING METER FOR REGULATING A FLUE DAMPER This is a continuation in part of my previously filed application Ser. No. 70,531 now abandoned.

This invention relates to a modulating meter and controls utilized to actuate a reversible motor that is in turn connected to a damper in a chimney to increase or decrease the desired draft and means to indicate all operations.

In view of the enormous loss of heat expelled through chimneys where a draft control is either not used or is not regulated, it is an object of this invention to provide a reversible motor driven draft control with the motor electrically connected through a modulating meter that responds to changes in the fluid pressure or draft within the chimney.

An object of this invention is to utilize two photoelectric cells with a gauge connected to a device to be monitored in which the movement of the pivotally mounted pointer will trigger either of two reactions, to increase or decrease the response of the device being monitored and maintain a desired setting.

A further object of this invention is to mount two photoelectric cells pivotally with relation to the movement of the indicating pointer of a gauge that is connected to a device to be monitored so that said photoelectric cells may be adjustably positioned to a predetermined position to in turn determine the area in the travel of the indicating pointer of the gauge at which either photo-electric cell will trigger a reaction to in-- crease or decrease the response of the device being monitored and maintain a desired setting.

A still further object of this invention is to utilize a photo-electric monitored gauge according to this invention to control a boiler over fire draft to maintain the draft setting specified for that boiler.

A still further object of this invention is to utilize a photo-electric monitored gauge according to this invention to control the repeating time interval of the operation of a device and maintain the desired setting without over-running or under-running the time intervals.

A sitll further object of this invention is to provide two photo-electric cells mounted with relation to the pointer of a gauge and responsive to the movement of said pointer and in combination with a triggering device and provided with a circuitry for maintaining a desired operational setting.

It is a further object of this invention to provide means to indicate the opening of said motor driven draft control to indicate a fully open draft and a zero chimney pressure at the end of each cycle of operation.

It is a further object of this invention to provide means to indicate a rise in chimney draft pressure to a predetermined high and after a timed cycle an automatic burner shut-off.

It is a further object of this invention to provide means to indicate no rise in chimney draft pressure after thermostat calls for heat and either the burner does not operate or the reversible damper does not open.

Other objects of this invention shall be apparent by reference to the accompanying detailed description and the drawings in which FIG. 1 is a plan view of a meter with a pivotally supported pointer and a pair of photo-electric cells,

FIG. 2 is a cross sectional view taken on line 2-2 of FIG. 1,

FIG. 3 is a plan view of the pointer and vane of the meter describedin FIG. 1,

FIG. 4 is a schematic illustration of the solid state circuitry connected to the photo-electric cells to maintain the desired setting for the operation and control of a reversible electric motor, and

FIG. 5 is a schematic illustration of an application of this device to the draft of a heating boiler.

Referring to the drawings and particularly FIGS. 1 and 2, there is illustrated an indicating gauge or meter 10. The meter 10 is a draft gauge Model MZR produced by Bacharach Instrument Company, whose address is 625 Alpha Drive, Ridc Industrial Park, Pittsburgh, Pa. 15238. This gauge is the same as that shown in the included circular from the company except for the pointer 14 shown in FIG. 3. The pointer 14 shown in FIG. 3 has been modified for this particular use of the meter. The gauge 10 is connected to a flue by a tube 30 and in which the diaphragm is responsive to the fluctuation of the external force from the fluid device, the fluid response effects the pointer 11 moving it pivotally to indicate the variation in the response. In this invention only the pointer 11 has been altered to include and have integrally formed therewith a vane 12 or shutter and a counterbalancing portion 14 all supported upon a pivotal shaft 1 1A so that vane or shutter l 2 will move pivotally in response to the movement of pointer 11. In addition, a pair of lamps l5 and 16 are positioned under the pivotal path of vane 12 in spaced relationship so that vane 12 can pivotally move to cover both lamps or move to cover either lamp while exposing the opposite lamp.

Lamps

15 and 16 are connected to a power source (shown in FIG. 4). A pair of photo

responsive cells

17 and 18 are mounted on an arm 19 that is pivotally supported on the axis of the pivotal shaft of the pointer and a projecting portion 20 is provided to permit manual movement of arm 19 to set arm 19 in a desired position over the vane 12. A cover 21 is provided to cover the lower portion of the gauge I which includes the pivotal shaft 11A and the pointer 11 and vane 12. However the cover has an arcuate shaped cut out portion 22 as illustrated in FIG. 1 so that the light rays from

lamps

15 and 16 are either blocked from

cells

17 and 18 by shutter 12 or cell 17 is blocked by shutter 12 while cell 18 is receptive to the light ray or vice versa to activate either cell according to the movement of pointer 11. The pointer 11 is normally at a null position as indicated in dotted lines indicating no response. Referring to the meter 10 illustrated in FIG. 1, this particular meter is responsive to the movement of a diaphragm to indicate a reading based upon inches of water. More specifically, the meter is a draft gauge and based on the variation in draft the response is translated to inches of water on the dial 10A of the gauge. This particular calibration is utilized with relation to the over fire draft specified for each boiler by boiler manufacturers. Thus in the installation of a particular boiler, the over draft specified is the desired setting for the operation of that boiler to maintain an optional but variable draft. The meter 10 as calibrated indicates 0.05 to 0.25 inches of water. With the meter 10 connected by means of a draft responsive tube 30 to the over draft of a boiler (not shown), the pointer 11 will respond indicating a draftreading. To maintain a desired over fire draft, a reversible damper 31 (FIG. 5) is installed in the chimney or outlet from the boiler and a reversible motor operated damper control 32 is connected to the damper 31. Thus by utilizing the draft gauge 10 that is responsive to the draft in a chimney or outlet 33, the draft gauge will indicate and maintain a visual indication of the over fire draft for that particular boiler. Since a recommended over fire draft is supplied for that particular boiler, the damper 31 is utilized to restrict or open the draft area of the chimney 33 to maintain the desired draft setting. In normal operation, a monitoring device 34 is connected to the reversible motor and the monitoring device 34 is activated or deactivated by a thermostat 35. The demand for heat by the thermostat 35 activates the monitoring device 34 which in turn operates the reversible motor 32 to open damper 31 to a fully open position. This may be performed in a 30 second cycle. With the damper 31 open, the reversible motor stops. The draft gauge 10 that is connected to the chimney 33 to indicate the draft response is then utilized according to a schematic circuit (FIG. 4) to be described. To control the operation of the reversible motor 32, driving motor 32 in one direction will result in closing the damper and the opposite direction to open the damper. The movement of the damper to restrict or open the draft changes the draft reading received by meter 10. Thus with a preferred setting of meter 10 according to the boiler specification, the draft control will maintain the desired draft which will be indicated by pointer 11 on meter 10. Referring to FIG. 1 (with the damper 31 in an open position (FIG. 5), the pointer 11 of meter is normally in the null. position. However, in use, if a prescribed over fire draft is to be set upon meter 10, arm 19 is moved pivotally by means of element 20 thus moving arm 19 downward (FIG. 1) toward the lower side of the cutout portion 22. This in effect will produce an activated setting uncovering cell 18. With cell 18 activated the circuit (FIG. 4) through element 34 (FIG. 5) is completed and the motor circuit is energized to drive motor 32 to close damper 31. As thedamper closes, the draft will be reduced as the draft reduces meter 10 will respond and the pointer 11 on meter 10 (FIG. 1) will move counter-clockwise and at the same time the shutter 12 will move counter-clockwise. When the pointer 11 reaches a predetermined setting as illustrated in FIGS. 1 and 3, the arm 19 having been preset at this setting by the positioning of the pointer, the shutter 12 moving counter-clockwise will reach a point at which the shutter will cover both

photocells

17 and 18 and this will de-activate the circuit through 34 and stop motor 32. When damper 31 (FIG. 5) reduces the draft to a predetermined degree, the response of meter 10 (FIG. 1) changes and pointer 11 will reach the desired reading at which point vane 12 will cover both

lights

15 and 16 and there will be no response of

cells

17 and 18 and the reversible motor will stop. However with changing conditions in the draft due to other reasons such as outside temperature and cycles of heating, the damper must be moved slightly either way, open or closed, to maintain the desired draft and thus pointer 11 will cause the shutter 12 to move clockwise or counter-clockwise uncovering either

photocell

17 or 18 and causing the control 34 to drive motor 32 in either direction until the varying condition subsides and the meter returns to a setting which indicates the desired draft.

Referring to the schematic circuit illustrated in FIG. 4, this is a no contact solid state switching circuit to be used in association with the photo-

electric cells

17 and 18 and the illuminating lamps l5 and 16 associated with the photo cells and the reversible motor 32 that is to be controlled. This solid state circuitry for the meter takes no load to actuate and provides optimum sensitivity for the meter. This is inherent in this system. The circuit may be described as with a power source of lines A and B connected to two

transformers

43 and 44 as illustrated. Transformer 44 is utilized to provide power for the lamp circuit. The transformer 43 provides power through the rectifier circuit for the amplifiers. Thus by means of the variable resistor 45, the

lamps

15 and 16 are provided with a differential setting by varying the light intensity. The other circuit is connected to one side of transformer 43, the opposite side of transformer 43 being connected to one side of a rectifier 42. The rectifier on its opposite side is connected to both

photo cells

17 and 18. The circuit from photo cell 17 is connected to amplifier 46 while the circuit from photo cell 18 is connected to amplifier 47. The

amplifiers

46 and 47 include electronic triggers actuated by the

triacs

40 and 41.

Elements

40 and 41 thus become the switching elements to energize either of the two circuits. When element 40 is triggered to an on state, it is connected to motor 32 to rotate motor 32 in a clockwise direction. When element 40 is de-energized, motor 32 will stop. And, when element 41 is triggered to energize the circuit to the opposite side of the motor 32, motor 32 will be driven in a counter-clockwise direction until element 41 is de-energized and motor 32 will stop. Thus it becomes apparent by referring to the combination of FIG. 1 and FIG. 4 that, with a meter such as the draft gauge 10 illustrated, the response of meter 10 indicated by pointer 11 affects the movement of vane 12. And with arm 19 preset by means of element 20, the

photo cells

17 and 18 may be both covered, that is, the vane 12 in a null position will intercept the light beam from lamps l5 and 16 so that

photo cells

17 and 18 are not activated. However meter 10, by means of pointer 11, may indicate a decrease or an increase in the draft response thus moving pointer 11 and in turn moving vane 12. For example, the movement of vane 12 in one direction may uncover photo cell 18 and the illumination from

lamps

15 and 16 will activate photo cell 18 thus triggering the circuit, FIG. 4, to drive motor 32 counter-clockwise. Or, the response from the draft gauge 10 may move the pointer 11 in the opposite direction so that vane 12 will cover photo cell 18 but uncover photo cell 17. Thus photo cell 17 is activated by

lamps

15 and 16 and the curcuit, FIG. 4, will be triggered and energized to drive motor 32 in a clockwise direction. Thus in operation with pointer 11, FIG. 1, at a desired setting according to the positioning of arm 19 as illustrated in FIG. 1, the gauge 10 will indicate any departure from a desired draft less or more by the movement of pointer 11 and an immediate response from the circuit, FIG. 4, will produce operation of motor 32 and according to FIG. 5, a correction of the position of the damper 31 counteracting the change in draft to re-establish the desired draft at all times during operation. Of course when the device is shut off, pointer 11 drops back to the dotted position illustrated and by means of the monitoring device 34, a circuit (not shown) simply closes draft damper 31 and the device is ready for a next cycle of operation when the oil burner goes on again. With each installation of meter 10 and the setting of arm 19 for a desired response, the

meter will retain the damper in a correct position. The pointer 11 of the meter 10 may have a very sharp setting or it may vary over a wider range before a response is required that is, pointer 11 may have a degree of fluctuation either side of a predetermined setting. This response is controlled by the differential setting produced through the lower circuit illustrated in FIG. 5 by changing the variable resistance 45 to increase or decrease the illumination of lamps l5 and 16. With maximum illumination, the setting or response of pointer 11 will be very sharp with very little variance from the position illustrated but with a minimum illumination produced by changing the variable rheostat,

lamps

15 and 16 will produce a minimum response with pointer 11 and therefore a broader or greater variance of the pointer 11 from its setting either side before triggering the circuit illustrated in FIG. 4 for operation of motor 32.

Although we have described the normal operation of the device as illustrated in FIG. 5, abnormal circumstances that may cause malfunctioning are also to be considered. In starting the operation of the burner, it is essential that we know that the damper has opened. Therefore a visual indication such as a lamp marked open being illuminated will insure this fact. Further in the event the burner is started, the damper is shown to be open and the meter continues to climb in pressure showing a high abnormal pressure, this is an indication of a malefunctioning such as the clogging of the flue or some obstruction to the flue and indicating a repair as necessary for proper functioning of of the draft control. Further, in the event the heat is called for and the meter 10 shows no pressure, a lamp marked no pressure would indicate that there is malefunctioning which may be the burner has not started, it may be that, although the burner has started, it remains open and is not controlled, the pressure may rise slightly but will fluctuate and therefore a correction must be made. Thus a visual indication of all desired conditions is included herein:

A. When the damper 31 is opened to indicate a clear draft for the burner, the draft operating arm 31A will close a circuit from ground through switch 50 to an indicating lamp 51 and from lamp 51 to the monitoring device 34 to provide the live connection to illuminate lamp 52. Thus lamp 51 will show that the damper is open.

B. When the pointer 11 of the draft gauge 10 moves to the extreme right to indicate a draft pressure buildup, a switch 52 is closed and a circuit is completed from ground through arm 11, through switch 52 to the lamp 53 and from lamp 53 to the monitoring device 34 to provide the live connection to illuminate lamp 53 indicating high pressure. This may be a red light to indicate danger or the necessity to check the chimney for blockage, preventing the escape of the flue gas pressure build-up.

C. Lamp 54 is connected on one side to the opposite side of pointer 11 of draft gauge 10 through a switch 55 and pointer 11 is grounded. The opposite side of lamp 54 is connected to 34 to provide a live connection to illuminate lamp 54. This indicates no pressure, that the burner is not operating. Another condition to be noted is that if pointer 11 of gauge 10 fluctuates back and forth, it is an indication that there is malfunctioning or no operation of the damper 31. The chimney 33 may also be provided with a light L and photo-cell P which also indicate that the burner is ON or OFF.

Although we have described the combination of a meter or gauge with a means of controlling the response of a pair of photo-cells to control the operation of a draft control for a heating plant as described, we may also provide the combination of this control with other devices to obtain a new result.

The invention described in detail in the foregoing specification is subject to changes and modifications without departing from the principle and spirit thereof. The terminology used is for purposes of description and not of limitation; the scope of the invention being defined in the claims.-

What is claimed is:

l. The combination of a modulating control meter and a draft control comprised of a pivotally operated pointer gauge that is responsive to fluctuating fluid draft conditions, said gauge including a fluid pressure responsive device to indicate an increase or decrease in pressure of fluid, said fluid pressure device including a diaphragm that is responsive to changes in fluid pressure, said diaphragm connected to a pointer in said gauge, said pointer pivotally mounted to be moved clockwise or counter-clockwise by said diaphragm as it responds to changes in fluid pressure, a shutter vane mounted integral with said pointer to move pivotally with said pointer, a freely movable arm pivotally mounted on the same pivot as said pointer and supporting a pair of spaced apart electro-optical photo-cells that are positioned to face toward said shutter, said photo-cell supporting arm connected to a manually adjustable knob to permit pivotally moving said arm clockwise or counter-clockwise to a desired setting, a pair of lamps to provide light rays to activate said photo-cells, said pair of lamps located below said shut ter, said shutter vane movable about a central axis and having a configuration that provides an intercepting cover portion for both of said photo-cells in a predetermined position and is so shaped as to uncover one photo-cell only when turned counter-clockwise and so shaped as to uncover the other photo-cell only when turned clockwise thus activating either photo-cell according to the direction of movement of said pointer and shutter, each photo-cell connected to an electronic switch and each switch connected to a reversible motor for draft control, means to drive said reversible motor in either direction to control said draft and means to indicate the result of said control.

2. In a device according to claim 1 in which said draft control is a chimney damper.

3. In a device according to claim 2 in which said chimney damper in a fully open position closes a circuit to an indicating lamp to show that said damper is open.

4. In a device according to claim 2 in which said modulating control meter includes a switch that is operative at a predetermined high draft and said switch connected to an indicating lamp to indicate that said damper is closed.

5. In a device according to claim 2 in which said modulating control meter includes a switch that is operative at a predetermined condition of draft and said switch indicate a malefunctioning of said damper.

Claims

1. The combination of a modulating control meter and a draft control comprised of a pivotally operated pointer gauge that is responsive to fluctuating fluid draft conditions, said gauge including a fluid pressure responsive device to indicate an increase or decrease in pressure of fluid, said fluid pressure device including a diaphragm that is reSponsive to changes in fluid pressure, said diaphragm connected to a pointer in said gauge, said pointer pivotally mounted to be moved clockwise or counter-clockwise by said diaphragm as it responds to changes in fluid pressure, a shutter vane mounted integral with said pointer to move pivotally with said pointer, a freely movable arm pivotally mounted on the same pivot as said pointer and supporting a pair of spaced apart electro-optical photo-cells that are positioned to face toward said shutter, said photo-cell supporting arm connected to a manually adjustable knob to permit pivotally moving said arm clockwise or counter-clockwise to a desired setting, a pair of lamps to provide light rays to activate said photo-cells, said pair of lamps located below said shutter, said shutter vane movable about a central axis and having a configuration that provides an intercepting cover portion for both of said photo-cells in a predetermined position and is so shaped as to uncover one photo-cell only when turned counter-clockwise and so shaped as to uncover the other photocell only when turned clockwise thus activating either photo-cell according to the direction of movement of said pointer and shutter, each photo-cell connected to an electronic switch and each switch connected to a reversible motor for draft control, means to drive said reversible motor in either direction to control said draft and means to indicate the result of said control.

5. In a device according to claim 2 in which said modulating control meter includes a switch that is operative at a predetermined condition of draft and said switch connected to an indicating lamp to indicate that there is no operation of said damper to regulate said draft.

6. In a device according to claim 2 in which said modulating control meter includes a switch that is operative at a predetermined condition of draft and said switch connected to an indicating lamp to indicate that there is an alternating on and off operation of said damper to indicate a malefunctioning of said damper.