Note: Descriptions are shown in the official language in which they were submitted.
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Back~round of the Invention
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This invention relates -to a solar energy collector
u-tilizing air or other fluid as the heat transfer media.
The initial cost and the efficiency of such collectors
have been the major problems encountered in constructing a
practical collector.
Collector units have been proposed employing flat
plates disposed to face the sun and over which air flows in
contact with the plates to pick up heat therefrom and transmit
the same to a storage unit or to a point of use.
Furthermore, it has been known to apply a black paint
to a flat-plate collector to provide a highly ef-ficient selective
sur-face giving good absorptance of solar energy.
In systems utilizing air as the heat pick-up media,
-there is a need for considering the optimum air velocity for turbu-
lent air flow in contact with the surface of the heated flat-plate
collector, and controlling the air flow in accordance with the
available heat. In general the higher the temperature o-f the
flat plate collector the higher air veloci-ty may be employed -for
a given output air temperature, and/or the higher will be -the
output air temperature ~or a given velocity o~ air. ~-
Since the sun does not always shine constantly upon
the collector, there may be frequent times in which the temperature
of the flat-plate collector drops because of lack of solar energy
25 input.
- Summary of the Invent on
The solar energy collector of the present invention is
constructed in modules generally disposed side by side and facing
the sun at a collector tilt determined by the climatic conditians
of the particular location.
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Each module cons-titu-tes a heat insulated enclosure
presenting a predetermined generally flat face of maximum area
tilt -toward the sun and which has a dual pane glass front for
transmitting solar energy to the flat-plate collec-tor within.
The flat-plate collector is of sheet metal such as
aluminum mounted by its edges within the enclosure and spaced
from the glass front to divide the enclosure into a front air
flow channel and a space in back of the flat~plate.
The back space is partitioned midway across the same
to provide support for the relatively thin flat plate in the
enclosure.
The lower part of the back space constitutes an inlet
chamber for air to directly contact the back of the -flat-plate
collector, and is in communication with the front air flow channel
15 by a transverse slot or other opening along the lower edge portion
of the flat-plate collector.
The upper part of the back space constitutes an outlet
chamber for heated air passing in-to it through a transverse slot
or other opening along the upper edge of the f~at-plate collector
from the front air flow channel. The heated air in the outlet
chamber directly contacts the back side of the fla-t-plate
collector to additionally remove solar energy therefrom.
The circulation of air through the collec-tor is
effected by a fan in a supply duct leading to the inlet chamber.
2~ A differential thermostat is employed to prevent actua-
tion of the an motor whenever a difference in temperature of less
than 7 F. is presen-t between the temperature of the air in the
supply duct and either the air in the outlet chamber or the
flat-plate collector in a region near -the upper edge of the latter.
The same differential thermostat additionally closes the supply
duct and the discharge duct unless the temperature differential
previously referred to does not exceed 7 F.
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Brief Description of the Drawinq
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The accompanying drawing illustrates the best mode
presently con-templa-ted o-E carrying out the invention.
FIGURE 1 is a ver-tical schematic view of a collector
unit and air flow system;
FIG. 2 is a perspective view of the collector of
Fig. 1, and
FIG. 3 is a front face view of the collector of Fig~ 1
with parts broken away to show the construction.
Description of the Preferred E bodiment
The module of the solar energy collector as illustrated
in the drawings, comprises a collector unit having an enclosure
or housing 1 with a generally triangularly shaped body portion 2
and with a horizontal bottom 3, and vertical back side 4. `
The body portion 2 of housing 1 merges on either side
with the wing portions 5 which extend .in a tilted plane across
the Eront of the body portion.
The front of the housing 1 is tilted to a position
reasonably normal to the rays of the sun at a prime -time of day~ ~
The body portion 2 and wing portions 5 are constructed ; ~ .
of heat insulating material such as and the front is
closed by one or more panels of dual pane glass 6 set in a
removable frame sealed to the body portion agains-t wea-ther leakage.
A flat-plate collector 7 is spaced from and preferably
parallel to the glass 6 and is supported at its edges by suitable
flanges or shoulders 8 in the walls of the housing.
The flat-plate collector 7 may be of any available
material having the ability to become hea-ted by the rays of the ;~ -
sun. That currently employed constitutes a thin sheet of aluminum~
copper or other metal preferably painted black with a composi-tion
o~ high absorptance of solar energy,
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The~ space in housing 1 behind the flat-plate collector
7 is divided by a transverse partition 9 in-to an inlet chamber 10
and an ou-tlet chamber 11.
The partition 9 extends from the bottom of the housing
1 to -the center of -the flat-plate collector 7 supports the latter
centrally against undue sagging.
The inlet chamber 10 is generally beneath and toward
the front -from the partition 9.
Chamber 10 is in communication with -the space 12 between
flat-plate collector 7 and glass 6 by means o-f a series o-f slots
13 or other openings through the collector plate 7 along the l
lower edge por-tion of the plate. ~-
The outlet chamber 11 is generally behind and above
the partition 9 and is in communication with space 12 by means
of a series of slots 1~ or other openings through the collector
plate 7 along the upper edge portion oE -the plate.
Air is supplied to inle-t chamber 10 through a pipe or
duct lS by means of a fan 16 providing forced flow of air throu~h
the collector.
Air is exhausted from outlet chamber 11 thraugh a plpe
or duct 17 to a storage unit 18 or to equipment utilizing the
heat from the air.
The air circuit as illustra-ted provides a continuous ;
flow of air through pipe or duct 15, inIet chamber 10, slots 13,
space 12, slots 14, outlet chamber 11, pipe or duct 17 and
storage unit 18 back to duct 15. The fan 16 is preferably
located between the storage unit 18 and cold air duct 15.
Control of -the flow of air through -the circuit pro~ides
a shut off for the fan 16 during periods when the solar energy
reaching the flat-plate collector is belo~ a predetermined
- minimum amount.
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For this purpose a dif-ferential thermosta-t 19 is
opera-ted by -two -temperature sensing probes, probe 20 in duct 15
and probe 21 in ou-tlet chamber 11 preferably à-ttached to the back
of the flat collector plate 7.
The -thermosta-t 19 opens and closes the energizing
circuit 22 for the motor 23 dr~ving fan 16.
A suitable differential temperature between probes 20
and 21 for actuating the thermos-tat is of the order of 7 F.
In other words, when sensing probe 21 is at least 7
F. warmer than sensing probe 20 the thermostat 19 closes the motor
circuit 22 to energize the motor 23 and dri~re fan 16, and when
the sensing probe 21 is not at least 7 F. warmer than sensing
probe 20 -the thermostat 19 will maintain circuit 22 open and ;~
motor 23 will not drive fan 16.
The heat storage unit 18 may be of -the rock type, or
it may be any heat exchange apparatus for transferring the heat
into storage material or into useful form.
In order to prevent loss of heat from unit 18 as by
air convection when the -fan 16 is not operating, it is desirable
to provide a damper 24 in duct 15 and a damper 25 in duct 17
actuated by suitable damper motors under the control of thermostat
19 to close the ducts when fan 16 is not operating and to- open
the ducts when fan 16 is operating.
The dampers 24 and 25 are particularly needed where
the collector unit is placed on the roof of a building 26 as
illustrated in Fig. 1, and the heat storage or heat exchange unit
18 is located in the basement of the building.
The housing 1 of the collector unit is constructed to
pro~vide for its location either on a slanting roof, as shownj on
a flat roof, on a vertical wall, or on an angular support providing
the required exposure of the flat collector plates 7 to the rays
of the sun,
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