US3198246A - Induction unit - Google Patents

Description

INDUCTION UNIT 3 Sheets-Sheet 1 Filed March 26, 1962 I N VEN TORS R ONALD W. BROWN WA LTER EA RHA RT ATTORNEYS Aug. 3, 1965 R. w. BROWN ETAL INDUCTION UNIT 5 Sheets-Sheet 2 Filed March 26, 1962 INVENTORS RONALD W. BROWN WALTER EARHA RT AT TORNEYS 1965 R. w. BROWN ETAL 3,198,246

INDUCTION UNIT Filed March 26, 1962 3 Sheets-Sheet 5 FIGS BY F/G.8 FIG.9 wmam United States Patent 3,193,246 TNDEUETEQN "UNTT Ronald W. Brown Walter Earhart, La Crosse, Wis assignors to The Trans Comp-any, La Crosse, Wis. Filed Mar. 26, W62, Ser. No. lldzdl il ll Elaiin. (til. 1165-35) This invention relates generally to air conditioning units and more specifically to induction type air conditioning units which employ a source of conditioned primary air to induce a secondary stream of room air through a heat exchange coil within the unit.

It is an object of the invention to provide an induction unit which employs a bypass for secondary air to control the temperature of the space being conditioned.

A second object of the invention is to provide an induction unit which employs a bypass for secondary air which is controlled by a damper member using the primary air as a source of motive power.

Another object of the invention is to provide an induction unit which employs the primary air as a source of power for the control as well as the motive force for a bypass damper.

A fourth object of the invention is to provide an induction unit which employs a new and novel nozzle structure which is readily assembled and inexpensive to manufacture.

These and other objects and advantages of the invention will more fully appear from the following description to be read in connection with the accompanying drawings in which:

FIGURE 1 is a front elevational view of the unit of this invention with portions of the cabinet broken away to disclose the interior construction;

FIGURE 2 is a cross-sectional view taken on line 2-2 of FIGURE 1;

FIGURE 3 is a schematic representation of the bypass damper control;

FIGURE 4 is a blown up view showing in detail the bypass damper and the attachment of the control bladder;

FTGURE 5 is a top view of the primary air regulator;

FIGURE 6 is a view taken on line 6ti of FIGURE 5;

FTGURE 7 is an end view of the regulator shown in FIGURE 6;

FIGURE 8 is an elevational view of the nozzle plate employed in the unit shown in FIGURES 1 and 2;

FIGURE 9 is a side view of the inducing nozzles with a portion of the nozzle member shown in cross-section; and

FIGURE 10 is a rear view of the nozzles shown in FIGURE 9.

Referring now to FTGURES 1 and 2, numeral 10 denotes a heat exchange unit of the induction type. Preferably induction unit ltl is mounted on a wall 12 a predetermined distance above the floor line 1 to define a kickspace to for the introduction of room air into the unit. This air is commonly referred to as secondary air.

In operation, primary conditioned air having a total pressure on the order of /2" to 5 water gauge is introduced into chamber 13 of the primary air plenum chamber 2t through inlet conduit 22. A regulator 24 to be described in detail hereafter regulates the flow of primary air from chamber 13 to chamber 25'. A triangular sound attenuator 26 is located in the primary air stream from the regulator 24 to attenuate the noise level of the primary air and to provide a restricted inlet portion 23 in order to obtain proper pressure conditions at the nozzle strips 36. Acoustical insulation 31 is connected to the walls of primary air plenum chamber ice and triangular sound attenuator 26 to dampen the sound inherent in the primary air stream.

Primary air ejected from the nozzle strips 3b into the inducing chamber 32 defined by the plenum chamber Ztl and the baflle member 33 induces secondary air from the kickspace either through the heat exchanger 34 or through the bypass passage 36 depending on the location of the bypass damper 33. The secondary air induced mixes in the inducing chamber 32 with the primary air from the nozzle strip 3% and is discharged into the conditioned area through discharge grille d0 in the top panel 42 of the heat exchanger unit ltl.

Regulator 24 shown in detail in FIGURES 5-7 consists basically of a lower plate 54 with louver portions 4-6 formed downwardly therefrom and an upper plate 48 slidably supported on the low plate with the louver portions 5t formed downwardly therefrom cooperating with louver portion 46 to provide a series of smooth edged adjustable orifices 47 for the passage of primary air from chamber 18 to chamber 25.

To control the sliding movement of upper plate 48, a control shaft 52 is rotatably secured in bracket 54 welded or otherwise secured to flanges 56 on lower plate 44 and is keyed to U-shaped bracket 5'8. U-shaped bracket 58 is telescoped over stud member 6t rigidly secured to upper plate 48. It should be noted that slot shaped aperture 62 in U-shaped bracket 58 is considerably larger in diameter than stud member which projects therethrough.

In operation, control shaft 52 is rotated clockwise or counterclockwise by any suitable means to close or open orifices 47 respectively depending on the particular requirements of the area being conditioned. The slot shaped aperture 62 allows U-shaped bracket 5?; to swing in an arc and provide linear motion of the upper plate 48 to control the amount of opening of the orifices 57 by sliding the upper plate 48. Felt bead strips 59 are employed to allow the upper plate to be readily moved.

After the primary air has entered the primary air chamber through the regulator 24, it passes through the nozzle strips 3h shown in detail in FTGURES 8-10. Nozzle strips may be constructed of any suitable material such as metal or plastic; however, we prefer to make them of plastic. The nozzle strips 3t? consist of a plurality of nozzles d4 arranged in a row in the vertical direction. The longitudinal axes of the nozzles 64 makes an angle of 30 with respect to the nozzle strip 3b. This angle may be as small as 20 but it should not be greater than The cross-sectional area of each nozzle 64 decreases continually from the entrance of the nozzle to the throat or discharge face. The entrance to the nozzles 64 have smoothly rounded surfaces. For primary air pressures of about 1.5 inches water gauge we prefer to use nozzles having throat diameters in the range of .09 to .2 inch.

Nozzle frame mounting member an is suitably m0unted to the primary air chamber 25 forming the front side or" the chamber. Nozzle frame as has nozzle slots es formed therein to accommodate nozzle strips 3d. The number of nozzle strips and nozzle slots being dependent on the requirements of the space being conditioned.

To assemble the nozzle strips 36 to the nozzle frame 6'6, nozzle strip 36 is placed so that tabs 69 on the back of nozzle strip 349 align with oblong slots or notches 7G in the nozzle frame. The tabs ea are then placed in the slots 76) and the nozzle strip is slid downwardly in nozzle slot 68 until projection '72 engages the upper edge '74 of nozzle slot 68 to lock the nozzle strip lid in place. It should be noted that a space '76 is left between the tabs 69 and the front portion '78 of the nozzle trip to allow the tabs 69 to slide on the back of nozzle frame while the front portion '78 slides on the front of nozzle frame 66.

Looking now in detail at FIGURES 24, the operation of the bypass damper will be discussed. in the position shown in solid lines in FIGURE 2, the bypass damper 38 is abuttinga sealing member dti and is blocking the bypass passage 36 so that all the secondary air is being induced through the heat exchanger 34 to be conditioned.

in induction systems which employ a source of primary air, the primary air is normally supplied continuously which means that some system of control must be incorporated to maintain the proper temperature in the space being conditioned. This condition prevails on both the heating and cooling cycles. In the preferred embodiment shown, the bypass damper is employed to maintain the proper temperature in the conditioned space. T his is accomplished by controlling the amount of air induced in the heat exchanger and at the same time inducing room air through the bypass passage 3d to mix with the primary air and the secondary air passing over the heat exchanger. Bypass damper 38 modulates from the position shown in solid lines where all the secondary air is induced through the heat exchanger 34 to the position shown in dotted lines where all the secondary air is being induced through the bypass passage 36. At intermediate positions between these two extremes, a mixture of bypass air and conditioned air will be induced into the inducing chamber 32 to be mixed with the primary air.

In the lower portion of the induction unit It? the bypass passage is defined by the bypass damper 33 and the front panel 32.

The bypass damper consists of three basic components. These components are the bladder containing member 34 connected to the heat exchanger 34 in any suitable manner, the bypass damper blade 33, and a strip of spring steel 86 or suitable substitute attached at its lower end 88 to the bladder containing member 34 and to the bypass damper blade 38 at its upper end by suitable means such as screws 92.

As indicated in FIGURE 4, the inflation and deflation of the flexible bladder member 94 controls the position of the bypass damper 33. At the fully inflated position indicated in dotted lines in FIGURE 2, the bypass passage 36 is open and the air passage through the heat exchange member 34 is closed. Conversely, when the bladder member 94- is deflated the damper 3% assumes the position shown in solid lines closing off the bypass passage 3i; and allowing all the secondary air to be induced through the heat exchanger 34.

The inflation and deflation of the bladder member is preferably accomplished by the use of a source of air under pressure. in the preferred form of the invention, the source of air employed is the primary air delivered to the unit. Obviously, a separate air source could be employed but the use of the primary air already present in the system eliminates the use of additional equipment and provides a unit which can be considered self contained and does not need additional wiring or pneumatic lines for control.

Cooling Looking now at FIGURE 3, the control will be explained. Basically, the control consists of a pressure reducing valve 96, a temperature reversing valve 9%, and a pneumatic controller lltiti. The control as shown is in the position when cold heat exchange fluid is being supplied to the heat exchanger 34 via conduit ltd. and the thermostatic bulb Mid is indicating a demand for cooling in the conditioned space.

Reversing valve 93 is providing communication between conduit Kidd and bleed line llti'd since thermostatic element llltl is sensing a cold fluid in conduit M32 and thereby being in its contracted position allowing spring 112 to force valve ball 114 against valve port 116 to cut off communication between conduit 1% and bleed line 113.

Control air at the proper pressure is being supplied to conduit lit-=6 through pressure reducing valve Eh: and restricter Mu from the primary air plenum chamber 2% or other suitable position. Flexible bladder is in its deflated position allowing all the secondary air to be induced through the heat exchanger 34 since bellows member 122 is in its expanded position indicating a need for cooling in the conditioned space and thus causing flapper member 124 to be pivoted away from bleed line 1% allowing the control air from conduit 1% to bleed to the atmosphere rather than build up pressure in the conduit 126 and flexible bladder member 96.

As the temperature in the conditioned space approaches the required temperature, the bellows 122 will contract allowing the spring 128 to pivot flapper member 124 tow. 5.5 the bleed conduit and restricting the flow of control therefrom. T he pressure in conduit 12d and flexible bladder 94 will increase causing the bladder member 94 to pivot the bypass damper blade towards the primary air plenum chamber 2%} thereby opening the bypass passagv and restricting the conditioned air passage. The amount of opening and closing of the bypass air passage being dependent on the required conditions of the conditioned space as set on the pneumatic controller fifitl. When the temperature in the conditioned space is completely satisfied, bleed line A58 will be totally restricted allowing flexible bladder 94 to be expanded to the dotted line position thus allowing all the induced air to pass through the bypass passage as.

Heating Assuming now that heating fluid is being supplied to heat exchanger 34 through conduit 7. 92, the thermostatic element 11% of the reversing valve 98 will be expanded forcing valve ball 114 upward against the bias of spring 112. closing off bleed line res and opening valve port 116 to provide communication between conduit 1% and bleed line 118. This reverses the action of pneumatic controller 109.

When the temperature in the space being conditioned is low indicating a need for heat, bellows 122 will be contracted allowing spring 123 to pivot flapper arm 12d away from bleed line 113 and thereby bleeding the control air to the atmosphere. Flexible bladder member 94 will then be in the deflated position causing damper blade id to be in the solid line position closing off the bypass passage 36 and allowing all the secondary air to be induced through the heat exchanger 34.

As the temperature of the conditioned space approaches the required temperature, bellows 12 will expand and pivot flapper member 124 towards bleed line 118 to r strict the flow or" control air therefrom. Flexible bladder member will then start to expand, since the pressure in conduit 1% and the bladder is increasing, causing the damper blade 33 to be pivoted towards the primary air plenum chamber As before, the bypass passage will be opened and the conditioned air passage will be restricted. When the temperature in the conditioned space is satisfied, the flexible bladder will be fully expanded to the dotted line position closing off completely the flow of secondary air through the heat exchanger 34 and allowing all the secondary air to be induced through the bypass passage 36.

The above described induction unit is very compact and does not require any external wiring or piping other than the primary air conduit. This induct on unit is readily assembled, more inexpensive to manufacture, and provides a compact unit which lessens the amount of worlr necessary to place it in operation.

Although we have described in detail the preferred embodiments of our invention, we contemplate that many changes may be made without departing from the scope or spirit of our invention and We desire to be limited only by the claim.

enemas We claim:

An air conditioning unit adapted to be mounted against a wall, in a conditioned space a predetermined distance above the floor comprising: a substantially rectangular casing, a recirculated air opening in the bottom of said casing, a discharge opening in the top of said casing, said casing having a front panel, a heat exchanger mounted in the lower portion of said casing and inclined upwardly and rearwardly at an angle to said front panel, one corner of said heat exchanger being adjacent the rear of said casing, means forming a passage extending from below said heat exchanger between said front panel and said heat exchanger to bypass recirculated air, a primary air plenum chamber supported in the upper portion of said unit, means for supplying air under pressure to said primary air plenum chamber, regulating means dividing said primary air plenum chamber into a first chamber and a second chamber, said supply air being delivered to said first chamber, nozzle means connected to said second chamber, damper means pivotally supported between i said bypass passage and said heat exchanger, and control means operably associated with said damper means to control the pivoting of said damper means in response to load conditions to regulate the proportions of recirculated air induced through the heat exchanger and the bypass passage by said nozzle means.

References Cited by the Examiner UNITED STATES PATENTS Bodmer 137-62533 Ewald 165-40 Ewald 236-38 Stacey 98-40 Matner et a1.

Mercier et al. 137-62533 Broberg 98-40 Peple 98-41 Pfarrer 251-61 McDonald 236-13 Newton 165-123 X Bottorf et al 165-123 Ashley et al. 98-40 Millman.

Ashley et al. 98-38 X Ashley et al 165-26 Great Britain.

ALDEN D. STEWART, Examiner.

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