US1862272A - Automatic stack damper - Google Patents

Description

June 7, 1932. V J. E LUDWIG 1,862,272

AUTOMAT IC STACK DAMPER Filed Aug. 51, 1928 2 Sheets-Sheet 1 7; j moentoz Jajuz 1 Ludwig arbor/"m June 7, 1932. J. E. LUDWIG AUTOMATIC STACK DANH ER 2 Sheets-Sheet Filed Aug. 51. 1928 wucnfor JnhzzELzrdzzrig Patented June 7, 1932 STAS JOHN E. LUDWIG, OF DETROIT, MICHIGAN, ASSIG-NOR TO NEWCOMB-DAVID G0. INC, OF

DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN AUTOIEATIC STACK DAMPER Application filed August 31, 1928.

The present invention pertains to a novel automatic damper for controlling air currents through Ventilating stacks, of the type employing an induced draft.

The primary object of the present invention is to eliminate unnecessary expenses by avoiding loss of heat over night from factories and similar large buildings, through the ventilator pipes. The loss ordinarily is considerably large, due mainly to the fact that the heat escapes through the ventilating pipes after the work of the factory has been suspended, and there being no further necessity for ventilation as the machinery has ceased to operate. Ordinarily the stack pipe remains open after operations in the factory have been suspended. This admits cold draughts and the elements toenter the rooms and also allows warm air to escape.

A further object is to devise an automatic damper having controlling means governed by the siphon means which causes the ventilating currents. The siphon means consists of a nozzle directing a flow of air upwardly in the stack pipe, the damper operating mechanism being attached to the nozzle and caused to move by the flow of air through the nozzle. The dampers are so constructed that immediately the air flow is discontinued the damper automatically closes and seals the pipe, preventing all circulation of air or draughts through the stack pipe.

With these and other objects in view, the manner in which I attain these objects is fully disclosed in the following description, with reference to the accompanying drawings, in which Fig. 1 is a plan View of the damper mechanism taken on a cross section through the stack pipe;

Fig. 2 is a cross sectional view on the line 22 of Fig. 1

Fig. 3 is a cross sectional view on the line 3-3 of Fig. 2;

Fig. 4 is a side elevation. of a section of the stack pipe partly broken away. showing a slightly modified embodiment of my invention; and

Fig. 5 is a cross sectional view on the line 55 of Fig. 4.

Serial No. 303,135.

Similar characters of reference are employed to designate the corresponding parts throughout the several views.

In reference to the embodiment disclosed Figs. 2 and 3 of the drawings, being formed.

with the tapered portion 3. The tapered portion?) accommodates brackets 4 which are formed with upwardly extending ears, providing suitable means for pivoting shutter members 5. The shutter members are piv otally connected by the cross members 6, the cross members causing the several shutter members to move in unison.

' A pipe 7 is provided at its outer end with a suitable air blowing device not shown). the inner end, extending through the wall of the pipe 2, is formed with a nozzle 8. which directs the air at a great velocity upwardly in the stack pipe. The nozzle 8 is formed with a flange 9, and a cover plate 10 is hinged, as at 11, to the flange 9. The outward ends of the hinge 11 and connected to the cover plate and movable therewith, are provided the arms 12. these arms 12 being connected. at their outer ends. to the cross members 6 on the shutter members. by means of flexible cords or chains 12.

The cover plate 10 is further provided with an angularly extending arm 14 to which adiustably secured is the weight 15, the weight being movable along the arm 14 and having a set-screw 15 by which it may be secured at any point on the arm 14. The weight 15 is thereby capable of counterbalancing the cover plate 10 and the arms 12. upon the hinge 11. so that a comparatively small air pressure through the nozzle 8 will move the cover plate 10 outwardly and upwardly on the hinge 11.

Adjustment of the weight or any of the parts needing replacements may be conveniently made by access through the door 16 in the section 2 of the stack pipe.

In operation. of the embodiment described, the air being forced through the nozzle 8. forces the cover plate 10 upwardly upon the hinge 11, and at the same time correspond ingly raising the arms 12. The arms 12, being in connection with the shutters 5, by means of the flexible connection 12 and the cross members 6, upon the movement described cause the shutters 5 to assume the erect, or open position, indicated in Figures 1, 2 and 3 in the drawings.

Immediately, in event of the air flow through the nozzle 8 being discontinued, the cover plate 10 lowers until in a flat position upon the flange 9 on the nozzle 8. The arms 12 are correspondingly lowered with the cover plate 10 and thereby allow the shutters to settle to the position indicated by the broken lines in Figure 3.

In the embodiment disclosed in Figures 4 and 5 is shown a section 20 of a. ventilator stack having a pipe 21 extending through the wall of the stack. The pipe 21 is turned upwardly within the stack and is pro sided with a nozzle 22. A cover plate 23 is hinged over the nozzle 22 by means of the integral rod 24 being supported in hearings in the stack pipe 20, the cover plate 23 being counter-balanced by the adjustable weight 25 upon the arm 26.

A butterfly damper 27 is pivoted within the stack section 20 upon a rod 28 which e);- tends outwardly of the stack 20 and is provided with a cross arm 29 connected at its center to the rod 28 so as to turn therewith. Connected to one end of the arm 29 is a link 30 having a pivotal connection at its upper end to a lever arm 31 attached to the rod 24, the other end of the arm being provided with the weight 29.

In operation the air rushing through the nozzle causes the cover plate 23 to rise upwardly, turning the rod 2d and ra sing the lever arm 31. The link connection 30 in turn causes the arm 29 to turn the rod 28 and move the butterfly damper to an open position. When the air flow is discontinued through the nozzle the cover plate returns to a position flat upon the nozzle and butterfly valve assumesthe closed position. The weight of the link connection being sufficient to return the parts of this position, the parts being counterbalanced by the weights 25 and 29 so as to require a comparatively small pressure to operate.

The air, in being ejected from the nozzle in the ventilator stack at a high velocity, due to a loss of pressure caused by the reduction in cross sectional area of the pipe 7 or 21, tends to create a partial vacuum below the nozzle. The air is drawn from the room to fill this partial vacuum and is passed onwardly up the stack to the atmosphere.

The dampers are caused to open or close by the means creating the suction, opening or closing in response to the said means, The passage is thereby automatically closed immediately there is no need for air circulation and thus eliminating all waste of heat and neeaare sealing the connected room from the elements.

Although specific embodiments of my invention have been illustrated and described, it will be understood that various alterations, in the details of construction, may be made without departing from the spirit of the invention, as indicated by the scope of the appended claims.

lVhat I claim is:

1. The combination with a ventilator stack of a plurality or pivoted shutters adapted to prevent circulation of air through said stack when said shutters lie in a horizontal position, a nozzle adapted to create a flow of air "1 said stack above said shutters, a pivoted plate adapted to lie flat on the opening in said nozzle whereby a flow of air through said nozzle causes said plate to assume a vertical position, and connecting means between said shutter and plate for causing said shutters to assume a vertical position when said plate is moved to a vertical position by the flow of air through said nozzle.

2. In combination, a ventilator staclr, an air conducting conduit having one end ere tended within the ventilator stack for creat ing a flow of air through the stack, a normally closed damper in the stack below the conduit, a plate pivotally mounted on the discharge end of the conduit and normally urged to a position to overlie such discharge end and moved to a position. at right angles to its normal position during the passage of air through the conduit, and an operative connection between the plate and damper to open and close the latter incident to the movement of the plate.

3. In combination, a ventilator stack having the discharge end of a pressure conducting conduit extended therein for creating a flow of air through the stack, a plate pivoted on the discharge end and normal y urged to a position to overlie the discharge end and raised to a perpendicu ar position by the passage of pressure through the conduit, an arm attached to the plate, a damper in the stack, and an operative connection between the arm and damper whereby to control the latter incident to the movement of the plate on its axis.

4. In a control for ventilator stacks, a damper for controlling ventilation through the staclr, a plate adapted to be pivotally sup ported on the discharge end of a pneumatic ejector arranged to discharge above the damper, an arm attached to one side of the plate, and an operative connection between the arm and damper whereby the latter will be controlled incident to the movement 01 the plate by the pneumatic pressure discharged against the plate from the pneumatic ejector.

In testimony whereoi. I aflix my signature.

JOHN E. L'Unwre.

Images