US3395752A

US3395752A - Baseboard heat exchanger apparatus

Info

Publication number: US3395752A
Application number: US556678A
Authority: US
Inventors: Andrew J Fowell
Original assignee: American Standard Inc
Current assignee: Trane US Inc
Priority date: 1966-06-10
Filing date: 1966-06-10
Publication date: 1968-08-06
Anticipated expiration: 1985-08-06

Description

1963 A. J. FOWELL 3,395,752

BASEBOARD HEAT EXCHANGER APPARATUS Filed June 10. 1966 INVENTOR. Andrew J. Fowell AT'T ORNEY United States Patent 3,395,752 BASEBOARD HEAT EXCHANGER APPARATUS Andrew J. Fowell, South Bound Brook, N.J., assignor to American Standard Inc., a corporation of Delaware Filed June 10, 1966, Ser. No. 556,678 4 Claims. (Cl. 16555) ABSTRACT OF THE DISCLOSURE This invention relates to a forced air baseboard heat exchanger unit. The unit includes a crossflow fan, a housing having a scroll adjacent to the fan, and a heat exchanger mounted above the fan and within the housing. The fan is made of a hollow cylindrical member formed of expanded sheet metal and is retained between flat end plates to which shaft means are connected so that the member may be rotated. The fan is positioned near the bottom of the housing which has an opening extending substantially across the length of the housing and over the entire axial extent of the rotor. The heat exchanger extends along at least a portion of the length of the housing.

This invention relates to a forced air baseboard unit utilizing a crossfiow fan for both the heating and cooling operations, and to the structure of the crossflow fan that is utilized and specially adapted for use in such baseboard unit.

Hydronic air-heating baseboard units, consisting of finned tubing, are at present limited to heating applications, because they rely on convection for the removal of heat from the unit. The heat distribution throughout the room is similarly achieved through convection. Such heat is derived from heated water transferred through the tubing, which then conducts the heat to the fins from which the heat is transferred to the air by the convection movement.

If cold water is passed through the tubing of such a unit, a layer ofcold air is formed across the floor of the room. If a suitable fan were available to circulate the air from the floor over the finned unit of the baseboard and then to discharge the air into the higher parts of the room, such a hydronic baseboard type unit could be used for cooling applications during the summer as well as for heating in the winter.

One object of this invention is to provide a suitable fan of special design and construction to circulate air from the lower level onto and over the finned unit of such a baseboard unit and to discharge the air to the higher parts of a room.

Another object of the invention is to provide a baseboard style unit which can be utilized for cooling applications as well as for heating applications, and which includes a crossfiow fan specially adapted for use in such a unit.

One of the main advantages of a crossflow fan, compared with a standard centrifugal fan, is that its total air delivery is approximately proportional to the length of the rotor, as a result of the tangential rather than axial air inlet. Such a crossflow fan is frequently used when a long narrow air supply is required or particularly advantageous.

A long crossflow rotor with blade supported parallel to the rotor axis, suffers from a number of structural weaknesses. Firstly, centrifugal loads or forces cause the blades to bend outwards and to touch the casing, or to cause unbalance. Secondly, such a bladed construction of the rotor has very low torsional stiffness, and therefore, lacks torsional stability or rigidity. Furthermore, expensive dies are required to make the bladed rotors, as a re- 3,395,752 Patented Aug. 6, 1968 salt of which, they are costly to produce. Further, straight axial blades also produce an undesirable edge tone when passing the cut-off edge of an outlet port for the air stream being moved.

An object of this aspect of the invention is to provide a crossfiow fan rotor that shall avoid the foregoing disadvantages and yet be economical to manufacture.

Another object is to provide a crossflow fan rotor which while being inexpensively constructed has substantial torsional rigidity.

Another object of the invention is to provide a crossflow fan rotor having a peripheral structure which will provide a relatively stable and torsionally rigid element, with natural symmetry, and with relatively uniform axial mass, that will permit a number of such rotors to be connected together end-to-end and driven from one end, when appropriately supported axially.

Initially, the invention contemplates a rotor for a crossflow fan comprising a hollow cylindrical member formed from a sheet of expanded metal. End plates are connected to the peripheral edges of the member. A shaft means is connected to each of the end plates for rotating the member about its cylindrical axis.

Further, the rotor can be incorporated into a crossflow fan by disposing a scroll about the rotor. The scroll extends substantially across the entire axial extent of the rotor and only along a portion of its circumferential extent.

Finally, the crossflow fan can be incorporated in a temperature control unit by disposing the fan in a housing having an air inlet near its bottom and an air outlet near its top. In the housing, above the fan, there is a heat exchanger so that air drawn in from the bottom of the housing is forced by the fan across the heat exchanger to the outlet of the housing.

Other objects, the features and advantages of the invention are more fully described in the following specification, which may be considered with reference to the accompanying drawings, which show by way of example and not limitation, the now preferred embodiment of the invention.

In the drawings:

FIGURE 1 is a transverse vertical sectional view of a forced-air temperature control unit of the baseboard type with a crossflow fan according to the invention;

FIGURE 2 is a similar transverse vertical section, partially in elevation, of a modification of a crossflow fan forced-air baseboard unit of FIGURE 1;

FIGURE 3 is a side elevational view of the rotor of the crossflow fan of FIGURES 1 and 2; and

FIGURE 4 is a transverse sectional view of the rotor of FIGURE 3 showing the general disposition of the rotor relative to a schematic duct into which the rotor is to direct and drive the air stream.

As shown in FIGURE 1, the baseboard unit 10, for heating or cooling a stream of air and then directing such heated or cooled air stream into an adjoining space, such as a room or compartment is usually disposed against a wall. The elements of the baseboard unit 10 include a finned heat exchanger 25 to serve as a heating and cooling unit, a rotor 30, disposed below the finned heat exchanger 25, a lower conduit-forming scroll 32 to define a horn opening space 34 for the air stream to be driven, by the rotor 30, upwardly past the heat exchanger 25, and an upper region 35 which defines one end .of an outlet or discharge passage 38. The size of passage 38 is defined by louvers 40, that are angularly adjustable, in the passage 38, between the nose 36, of the upper region 35 and an upper edge 42 of a front facing wall or sheet 45 that extends along the length of the baseboard unit. Sheet 45 serves as a front wall of the boxlike structure for enclos- 3 L ing the-operating length of the baseboard unit 10. The lower end 'of' the front wall 45 is provided with an opening for an inlet 48 which includes a filter, that extends downward to a front sill or'base portion 50 at the lower front end of the lower scroll 32, adjacent the rotor 30'. The sill 50 and the bottom of the scroll 32 of which it forms a part are shown in the usual position resting on the floor 52 of the room or compartment that is to receive the heated or cooled air from the baseboard unit.

A condensate drain 54 is shown supported on the rear wall 20 at a position where the drain 54 will receive any moisture that drips olf the fin structure of the heat-transfer element 25.

Heat transfer element 25, which may serve either as a heating or as a cooling element, consists of a conduit or pipe 55, preferably of good heat conducting material, such as copper or brass, to which a series of parallel fins 57 of heat conducting material, also such as copper or aluminum, are mechanically joined, to provide a good heatconducting connection. Fins 57 may be individual stampings, relatively square, as shown, or the fin structure may consist .of a continuous metallic strip, helically wound on the tubing 55 and joined to the pipe or tubing 55 along the inner contacting edge of such helically wound material.

Where the fins 57 are substantially of square shape or of rectangular shape, the lower edges 58 are slightly inclined in order to provide a pitch along which any moisture collecting on the fins, during cooling operation, will flow to the corner 59 of the fins and then drop off into the condensate drain or gutter 54, which in turn may then be suitably connected to drain off to a sewer drain (not shown).

The modification of the baseboard unit 10, as shown in FIGURE 2 is primarily concerned with an alternate embodiment for condensate removal. A lower scroll 62 is provided with suitable openings or perforations 64 at the bottom level so that the moisture that may condense on the fins 57 will drip off the lowermost corner 59, drop into the curved lower scroll 62 and run off at the lowermost point at the openings 64 into the condensate drain 66 from which any accumulated moisture there collected may be drained off into a suitable conduit leading to a sewer drain pipe. The remaining elements of this baseboard unit are the same as the elements of the baseboard unit 10 of FIGURE 1.

The construction of the rotor 30 may now be considered. As shown in FIGURES 3 and 4, a sheet of expand metal mesh 70 is formed into a cylinder, and its longitudinal side edges then appropriately secured as by welding or soldering, to hold the cylinder as a closed structure. Two

end plates

74 and 76 are secured at the outer edges of the cylinder 72 to support and hold the cylinder 72 in symmetrical co-axial alignment with the two

end plates

74 and 76, all of which constitute a lightweight, relatively rigid and stable structure. The two

end plates

74 and 76 are provided with

axial bosses

78 and 79 that may serve as end shafts for the cylindrical fan 30 thus formed, or those

axial bosses

78 and 79 may be utilized as connecting bosses or terminals to permit two adjacent coaxial rotors to be mechanically coupled and driven by a single driving motor connected to any one of the outer axial shafts such as 78 or 79.

As indicated in FIGURES 3 and 4, the larger flat side edges or webs 80 of the diamond shaped perforations formed in the expanded metal mesh 7 0, function as shallow radially extending ribs parallel to the axis of rotation, and in most effective position to serve as vanes to move the air, along the entire peripheral part of engagement between those webs 80, of the diamonds of the mesh, and the air directly engaged by those webs. As seen in FIG- URE 4, the webs 80 are aligned in a direction forward of radial. Consequently, the fans are operative to move the air in a path from an inlet region of first engagement with an incoming air-flow stream to the outlet region at the mouth of a substantially exponential-shaped horn, as defined in the space between the virtual periphery 'of the rotor 30 and the surface of the lower scroll 32 of FIG- URES l and 4, for example, or between the rotor and the lower scroll 62 of the modification in FIGURE 2.

The operation of the entire combination may now be considered. j I I .l

The fluid conducting pipe 55 filled with'a'stream of water at elevated temperature for heating-purposes. The heat from the water in the pipe 55 is then transmitted to the fins 57, and air drawn in through the inlet 48 is driven upwardly by the rotor 30, along the scroll 32 and out of opening 34, through the spaces between the heated fins 57, and then upwards and through the passage 38, to the extent permitted by the position of the discharge louvers 40. The cold air from the floor level is thus heated in passage over the fins, and is then directed upward into the room or space according to the inclination of the discharge louvers 40. i

In the case where cooling action is desired, cold water is fed through pipe 55, and the air at floor level is drawn in through the inlet 48, as before, and directed and driven over the surfaces of the cold fins 57 and then similarly up past the discharge louvers 40 and out of the passage 38 into the space in the room or compartment.

Thus, either heating or cooling action may be achieved according to the temperature of the heating or cooling medium, such as the hot or cold water in the pipe 55, and the transfer of heat from the fins to the air or from the air to the fins, depending upon the nature and the direction of heat transfer for the air treatment.

By means of the construction shown, a quietly operating unit is achieved. In addition, an inexpensive and rigid rotor structure is obtained.

There will now be obvious to those skilled in the art many modifications and variation which satisfy the objects of the invention without departing from the spirit and scope thereof as defined in the appended claims.

What is claimed is:

1. A baseboard type of heat exchanger comprising: a vertically oriented, baseboard housing; said housing having an air inlet near the bottom thereof and an air outlet near the top thereof; a heat exchanger extending along at least a portion of the length of said housing; said heat exchanger com-prising a finned conduit; a scroll below said heat exchanger and having a length substantially equal to the length of the heat exchanger, said scroll having an outlet opposite said heat exchanger and an inlet opposite the air inlet of said housing; and a crossfiow rotor disposed within said scroll and extending substantially along the length thereof, said rotor comprising a hollow cylindrical member formed by a sheet of expanded metal and first and second flat end plates, each connected to one of the peripheral edges of said member; and shaft means connected to said end plates for rotating said member about the cylindrical axis thereof; said housing having means to collect condensate from said finned conduit.

2. The baseboard type of heat exchanger of claim 1 wherein said heat exchanger comprises a horizontally extending fluid conduit and a plurality of platelike radiating fins vertically extending from said conduit and further comprising a condensate collecting means disposed below said fins.

3. The baseboard type of heat exchanger of claim 1 wherein said platelike radiating fins include bottom portions oriented at angles to the horizontal, and said condensate collecting means being disposed to collectcondensate dripping from said bottom portion;

4. The baseboard type of heat exchanger of claim 1 wherein said sheet of expanded metal is provided with a two dimension array of perforations, each of said perforations having a length dimension greater. than the width dimension, said length dimensions being substantially parallel to the axis of said member, and webs extending between said perforations, certain of said webs being radial.

References Cited UNITED STATES PATENTS Pierce 165-55 X Walker 165122 X Harder 230134 Schlumbohm 230252 Simmons 62-291 6 7/ 1960 Tyler 62-285 X 9/ 1961 Mullin et a1 62291 X 8/1962 Allender 62-285 8/1965 Laing 230-125 X FOREIGN PATENTS 4/ 1964 Great Britain. 9/ 1962 Great Britain.

10 ROBERT A. OLEARY, Primary Examiner.

A. W. DAVIS, Assistant Examiner.