US2600933A - Unit heater - Google Patents

Description

B. SPIETH UNIT HEATER June 17, 1952 3 SheetsSheet 1 Filed Dec. 6, 1947 B. SPIETH UNIT HEATER June 1952 s Sheets-S 2 Filed ne 1947 haw.

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B. SPIETH June 17, 1952 UNIT HEATER 3 Sheets-Sheet 3 Filed Dec. 6, 1947 Jay @7202 Patented June 17, 1952 UNITED STATES ATE r FFICE This invention relates to unit heaters, and has been illustrated as a vertical delivery unit heater, although it may be used for horizontal delivery.

The invention relates primarily to a device having a heat exchange element, which element ordinarily uses steam or hot water as a heating medium and having a motor driven air circulating fan suitably located in the casing of the unit heater to draw air through the heat exchange element and discharge it into the space beyond the heater for comfort heating.

Another object is to provide a structure economic in the material used and adaptable for production on modern tools.

Another object is to provide a unit heater which may be mounted relatively high up in building structures, above cranes, or 'out of the way of various pieces of machinery and blow the heated air vertically downward into the space to be heated. This location of a unit heater also causes the warmer air that tends to rise to the ceiling, through buoyancy, to be picked up by the air blown by the unit heater and projected downward into the cooler space, thus an economy in operation results.

Another object is the provision of a duct around the motor through which cool air may flow past the motor for cooling purposes.

With these and other objects and advantages in view, this invention consists in the several novel features of construction, arrangement and combination of parts hereinafter fully described and more particularly defined in the appended claims.

The invention is clearly illustrated in the drawings accompanying this specification, in which:

Fig. 1 is a plan of a unit heater embodying a simple form of the present invention;

Fig. 2 is a side elevation thereof partly broken out to show parts in the interior of the heater;

Fig. 3 is a detail vertical section taken on the line 3--3 of Fig. 2; and

Fig. 4 is a perspective view of the rear of the heater casing and motor supporting elements.

Referring to said drawings, the reference character 5 designates the casing of the heater which is similar to the casing disclosed in my co-pend-ing application, Serial No. 790,122, filed December 6, 1947, and comprises upper and lower sections 5, I secured together as will be hereinafter set forth. The top Wall 34 of the upper section 6 is formed with an air inlet opening 8 preferably of rectangular form, and the bottom wall of the lower section I is provided with an air discharge opening 3 preferably of circular form and con- 10 Claims. (01. 257*137) 2 tained in a downwardly projecting annular flange I 0.

The two sections of the casing are formedwith outwardly struck up beads or ribs I I, which extend circumferentially around the sides of the sections. Said beads or ribs not only add to the ornamental appearance of the casing, but they strengthen and reenforce the same. The edges of the upper and lower sections 6', 7 are spaced slightly away from each other as seen at 12 ("see Fig. 3), and projecting into said space is an dutwardly struck up bead 13, formed on a joining strip I4 which may be welded to one of the casing sections as at 15-, and said strip overlaps the edge portion of the other section and is fastened thereto as by screws It, the edge portion of the casing section 6 and the joining strip [4 are depressed inwardly as at l1, l8 and the heads of the screws IS are contained in the depressions H. A name plate or other ornamented plate [9 overlies the edge portions of the adjacent edges of the sections 6, l and is secured to said sections by small screws Zil. The beads 13 end at places adjacent the name plate I9.

Supported in the upper end of the casing adjacent the air inlet is a heating element 22, which comprises an inlet header 23, and an outlet header 24 connected by tubes 25, upon which are strung fins 26. The inlet header 23 is connected to an inlet pipe 21 for steam or hot water, and the outlet header is connected to a discharge pipe 28. The heating element is carried by brackets 23c secured to the side walls of the casing section 6 A fan motor 23 is mounted upon a bracket 39 carried by one or a pair of supporting bars 3| which are bolted, riveted or otherwise secured to a pair of horizontally extending bars 32 the ends of which are bolted, riveted or otherwise secured to two wings 33 which project down into the interior of the casing from the inner edges of the inlet opening in the top wall 34 of the casing member 6, and provide battles to conduct the air from the inlet opening to the discharge opening v of the casing.

Any electric motor when operating under load, will, due to its normal characteristics become heated, and will eventually become overheated and be destroyed unless provisions are made to dissipate the heat. Experience has shown that motors must be adequately cooled, or insulation and windings will deteriorate rapidly and bearing grease will liquify and drain out to cause premature motor failure. Usually this heat is carried from the unit by convection of air currents. Ob-

inlet header to the outlet header between the baffles 33 and the baiiles 35, and the fins extend between the margin of the inlet opening and the other baffles 35, and some of the fins extend from the bafiies 33 to the baffles 35. Horizontal partitions or plates 37 extend inward from the lower edges of the baffles 35 and their inner edges are spaced from the motor to permit the air to pass around the motor. cool air passage around the motor.

With the air baflles surrounding the motor the heated air from the core is deflected around the motor, while at the same time the suction of the rotating fan causes cool air from 2 above the unit to be drawn down through an opening surrounding the motor. This cool air wipes over the motor housing in suificient quantity to keep the motor at a normal operating temperature. cooling the motor is drawn into the fan, but it is mixed with the heated air that was drawn through the core, and the temperature of the mixture is satisfactory for discharge into the space to be heated. By controlling the open area around the motor the amount of air passing is controlled and thus the cooling of the motor is controlled and may be maintained at a satirfactory temperature.

In the normal operation of the unit heaters there are periods when the motor is shut off, though the steam is still in the coil. Due to the relative closeness of the core and the motor, the motor could be overheated unless provision was made to keep it cooled. The motor is located somewhat below the core of the heating element, then when the motor is not operating there will be a natural circulation through the unit in reverse direction. The cool air enters through the fan area, passes upward around the motor and out through the air inlet area. The portion of the air that passes on outside of the air bafiies and through the core of the heating element, where it is heated and does not pass over the motor. shielded from radiant heat given off by the core, by the air bailies surrounding the motor. Therefore the motor is cooled by air that does not pass through the core whether unit is' in normal operation or standing by.

In the larger sized units where the motor weight is appreciable the mechanical arrangement outlined above permits of a hoist being attached to motor, and by removing certain fastenings the motor may be lowered to the floor separately, for service, or replacement without disturbing the suspension, steam piping etc. of the main unit assembly.

With the motor located relative to the other major parts of the assembly as shown, the fan can be directly connected to the standard length motor shaft. Thus special length shafts, auxiliary shafts, etc. are not required. This makes for simplicity and economy of parts and production.

Thus, there is provided a It is true that this air used for Furthermore the motor is A fan 38 is secured upon the shaft of the motor and discharges the heated air through an air deflector 39 of suitable form.

The heater may be suspended by hanger bars as, spot welded or otherwise rigidly secured to the bafiles 33, which bars may be connected to other hanger members as is customary.

While the heater has been shown and described as a vertical delivery heater, it may be set upright, if desired, to provide a horizontal delivery heater. In such case, an air deflector such as the one shown in patent to Benjamin Spieth, No. 2,413,118, dated December 24, 1946, may be substituted for the air deflector shown herein.

From the above it is apparent that I have provided a unit heater, which is simple in construction, composed of few parts, many of which are metal stampings. That the motor is shielded from the heated air passing through the casing and as a result is kept a normal operating temperature. The present unit heater provides a new power throw type of horizontal discharge unit heater. The velocity of the heated air discharged from the heater is appreciably greater than is obtained with other unit heaters now on the market.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence, I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combination of parts herein shown and described or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

1. A unit heater comprising a casing formed of two companion sections, means for securing said two sections together, said casing having an air inlet opening in one wall and an air dis charge outlet in an opposite wall, substantially parallel bafiles extending inwardly from the opposite edges of the air inlet, a pair of spaced supporting members extending transversely between and secured to said bafiles, a pair of spaced cross members inwardly extending transversely between and secured to said supporting members, bafi'les secured to said members and forming therewith a passageway spaced from the surrounding space in the casing, a fan motor in said passageway carried by one of said members, and a heating element within and disposed adjacent the air inlet and around said passageway, said passageway permitting cool air to flow past the motor.

2. A unit heater comprising a casing formed of two companion sections, means for securing said two sections together, said casing having an air inlet opening in the top wall and an air discharge outlet in the bottom wall, bafiies extending down from opposite edges of the air inlet, a pair of spaced horizontally extending supporting bars secured to said baflles, a pair of spaced horizontally extending cross bars secured to said supporting bars, bafiles secured to said bars and forming therewith a passageway spaced from the surrounding space in the casing, a fan motor in said passageway carried by one of said bars, and a heating element within and disposed adjacent the air inlet and around said passageway, said passageway permitting cool air to flow past the motor.

3. A unit heater comprising a casing having top, bottom and side walls, said top wall having an'airinl'et, and said bottom wall having a discharge opening, and there being oppositely" disposed baffles extending down from opposite edges of the inlet, spaced horizontally extending motor supporting members secured at their respective end to said baffles, spaced horizontal cross members secured to and extending between the motor supporting members, a motor supporting bracket mounted on one of said cross "members, a fan motor carried by said motor supporting bracket, bafiles secured to said two pairs of horizontal members and project 'ingup therefrom, said last mentioned baffles and horizontal supporting members providing a passageway around the motor for cool air, and a heating element positioned between said supporting members and the air inlet and surrounding the last mentioned baffles, the latter insulating the motor from the heating element.

4. A unit heater comprising a. casing having top, bottom and side walls, said top wall having an air inlet, and said bottom wall having a discharge opening, and there being oppositely disposed bafiles extending down from opposite edges of the inlet, hanger bars secured to said bailies, spaced horizontally extending motor supporting members secured to said bafiies, spaced horizontal cross members secured toand extending between the motor supporting members, a motor supporting bracket mounted on one of said cross members, a fan motor carried by said bracket, baflies secured to said two pairs of horizontal members and projecting up there from, said last mentioned baflies and horizontal supporting members providing a passageway around the-motor for the passage of cool air, and a heating element positioned between said supporting members and the air inlet and surrounding the last mentioned baffles, the latter insulating the motor from the heating element.

5. In a unit heater, the combination of a casing formed of front and rear companionable sections, the rear section having arear wall and side walls, said rear wall having an air inlet opening therein, the front section having a front wall and side walls, said front wall having an air outlet opening therein, means for securing said sections together along corresponding side walls, oppositely disposed, substantially parallel baffles formed by one of said sections providing the inlet opening and extending substantially the length of and inwardly from oppositely dis" posed edges of the air inlet opening in said section into the other section, a fan motor positioned in said casing, traverse support means including a pair of spaced supporting members connected to said baflies and a pair of cross members amxed to said spaced supporting members for supporting said motor therefrom, a fan rotatable by said motor operative to move air through said inlet between said baffles and discharge the same through said air outlet, and a heating element including inlet and outlet headers mounted in said casing contiguous to said inlet opening and between said baffles and interposed in the path of the air flow through said casing.

6. In a unit heater, the combination of a casing formed of front and rear companionable sections, the rear section having a rear wall and side walls, said rear wall having air inlet opening therein, the front section having a front wall and side walls, said front wall having an air opening therein, means for securing said sections together along corresponding side walls,

said air inlet and outlet openings being substantially axially aligned, one of said. openings being substantially rectangular in shape, oppositely disposed substantially parallel baffles formed by the section and providing said last mentioned opening, said baifies extending substantially the length of and inwardly from oppositely disposed edges of such opening into the other section, a fan motor positioned in said casing, means connected to said baiiles for supporting said motor therefrom including spaced transverse bars extending between said baflies together with other spaced transverse bars affixed to the aforesaid bars forming a passageway for receiving said motor, a fan rotatable by said motor operative to move air through said air inlet between said bafiies and discharge the same through said air outlet, and

a heating element including inlet and outlet headers mounted in said casing contiguous to said inlet opening and between said bafiles and interposed in the path of the air fiow through said casing.

'7. In a unit heater, the combination of a casing formed of front and rear companionable sections, the rear section having a rear wall and side walls, said rear wall having a substantially rectangular shaped air inlet opening therein, the front section having a front wall and side walls, said front wall having an air outlet opening therein, means for securing said sections together along corresponding side walls, said air inlet and outlet openings being substantially axially aligned, oppositely disposed, substantially parallel baiiles carried by said rear section and extending inwardly toward the front wall and oppositely disposed edges of the air inlet opening and into the other section, a fan motor positioned in said casing, means extending between and connected to said baffles for supporting said motor therefrom including supporting members extending transversely between ,and secured to said bafiles, a pair of spaced cross members inwardly extending between, and secured to said baffles, a pair of baffles secured to said members and forming therewith a passageway spaced from the walls of the casing, said fan-motor positioned in said passageway, a heating element mounted in said rear section of the casing and extending across the air inlet opening, and a fan rotatable by said motor positioned adjacent the air outlet opening and operative to move air through said air inlet and element, between said bafiles, and discharge the same through said air outlet.

8. As an article of manufacture, an upper section for a unit heater casing of a unit heater including a heating element, a motor-fan unit, and upper and lower sections, said unit heater casing adapted to support the heating element and the motor-fan unit, said upper section being complementally formed to the lower section and adapted to be detachably connected together, said upper section comprising an end wall and depending side walls, an inlet opening formed in the end walls, substantially parallel baffles extending inwardly from the end wall and forming the inlet opening, a pair of spaced supporting members extending transversely between and secured to said bafiles, a pair of spaced cross members inwardly extending between and secured to said supporting members, bafiies secured to said members and forming therewith a passageway spaced from the surrounding side walls of the casing, said passageway adapted to receive said fan motor, and one of said members adapted to support said fan-motor.

9. As an article of manufacture, a lower sec tion for a unit heater casing of a unit heater including a heating element, a motor-fan unit, and upper and lower sections, said unit heater casing adapted to support the heating element and the motor-fan unit, said lower section being complementally formed to the upper section and adapted to be detachably connected together, said lower section comprising an end wall and upstanding side walls, an air discharge opening provided in the end wall a streamlined downward projecting annular flange formed at the air discharge opening and adapted to receive the fan of the motor-fan unit, and an open ended annular shaped upwardly curved air deflector spaced from the end wall and also spaced from and carried by said annular flange, and

forming an annular air passage about said annular flange connected to the opening of the air deflector and said air discharge opening of said casing.

10. A unit heater including a motor-fan unit and a heating element and comprising a casing having side walls and formed of two complementally formed sections secured together, said casing having an air inlet opening in one wall and an air discharge outlet in an opposite wall, substantially parallel bafiles extending inwardly from the opposite edges of said air inlet, a pair of spaced supporting members extending transversely between and secured to said baffles, a pair of spaced cross members inwardly extending transversely between and secured to said supporting members, bafiles secured to said members and forming therewith a passageway spaced from the surrounding side walls of said casing, said motor-fan unit carried by one of said members with the fan positioned in said discharge outlet, and said heating element within and disposed adjacent the air inlet and contiguous to said passageway, whereby cool air is adapted to be circulated in said passageway downward about said motor with the motor operating the fan and upwardly through said passageway with the motor off, as heat is being supplied to the heating element.

. BENJAMIN SPIETH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,907,032 Askin May 2, 1933 2,120,795 Boothby June 14, 1938 2,332,762 Stempel et a1 Oct. 26, 1943 2,346,410 Ashley et al Apr. 11, 1944 2,504,798 Brinen Apr. 18, 1950 FOREIGN PATENTS Number Country Date 417,455 Great Britain Oct. 1, 1934 467,625 Great Britain June 21, 1937 520,674 Great Britain Apr, 30, 1940

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