EvΩPORATTΕ COOLED STORAGE AND DISPLAY UNIT DESCRIPTION OF THE INVENTION
The present invention relates to refrigeration, and display units for perishable items, and more particularly, to refrigeration and display units for fresh cut flowers and the like.
In the commercial floral industry, it has long been desirable to display fresh cut floral arrangements to customers and prospective customers in a manner that enables easy and thorough inspection, while at the same time maintaining and preserving their beauty. Since cut flowers begin to wilt in a relatively short time at room temperature, the ability to effectively display such floral arrangements has presented problems. Heretofore, it has been customary to store flowers in completely closed floral refrigerators. Not only are such refrigerators relatively expensive and costly to operate, they do not permit easy viewing of- the contained flowers. Instead, the refrigerator generally must be opened and the flowers, removed to permit thorough inspection.
It is an object of the present invention to provide an open storage and display unit that is adapted to permit easy viewing and inspection of flowers, while providing an environment about the displayed items that preserves their freshness and beauty.
• Another object is to provide an open floral storage and display unit as characterized above that maintains the displayed flowers in a cool, moist environment.
A further object is to provide a display unit of the foregoing type which is relatively simple in construction and economical to manufacture and operate.
Still another object is to provide a storage and display unit of the above kind that is equally useful for the display and preservation of fresh cut or picked vegetables and other perishables.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference of the drawings, in which;
FIGURE 1 is a perspective of an illustrative floral storage and display unit embodying the present invention;
FIGS. 2-4 are enlarged sections of the illustrated storage unit taken in the planes of lines 2-2, 3-3, and 4-4, respectively, in FIG. 1; and
FIG. 5 is a psychrometric chart illustrating the cooling and humidification cycle of operation of the illustrated unit.
While the invention is susceptible of various modifications and alternative constructions, certain preferred embodiments have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms described but, on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the scope of the invention.
Referring now more particularly to FIGS. 1-4 of the drawings, there is shown an illustrative storage and display unit 10 which, in this instance, contains fresh cut floral arrangements 13. It will be understood that while the storage and display .unit 10 will be described in connection with the storage and
display of flowers, the invention is equally applicable to the display of fresh cut or. picked vegetables and other perishables. For purposes herein, therefore, the term perishable is intended to encompass flowers, vegetables and other items which tend to deteriorate or lose their freshness in normal room temperature environments.
The illustrated storage and display unit 10 has a cabinet 11 which includes a lower compartment section 12 and an upper compartment section 14. The cabinet 11 preferably is supported on casters 15 for easy positioning. The' lower cabinet compartment section 12 has a top display shelf 16 and a plurality of front doors 18 suitably mounted to permit access to the interior of the compartment section. The upper compartment section 14 in this case has a relatively narrow width rear portion 14a extending upwardly from the rear of the lower compartment section 12 and a top portion 14b extending forwardly to a' point that is set back slightly from the plane of the front edge of the lower cabinet section shelf 16. Transparent side panels 19 are mounted at opposed ends of the cabinet between the display shelf 16, the upstanding rear cabinet portion 14a, and the top cabinet portion 14b, which together defines a viewing chamber 20 having a front opening 2a in a ■ plane inclined from the vertical at an acute angle which in this Case is about 20°.
For supporting and displaying flowers within the viewing chamber 20, the display shelf 16 is formed with a plurality of apertures 25a, 25b, which in this instance are arranged in front and rear rows, with each aperture being adapted to receive a floral vase or bucket 26. In the illustrated embodiment, the vase receiving apertures 25b of the front row are of
larger diameter than the apertures 25a of the rear row such that the vases 26 of the rear row are supported at a higher elevation than those of the front row, thereby supporting the floral arrangements of the rear row at a higher elevation for better viewing and easier access from the front of the viewing chamber 20. To further enhance viewing of the flowers 13, a lamp.28 is mounted in reeessed relation in the top cabinet portion 14b so as to illuminate the flowers while being out of direct view of persons inspecting the flowers from the front of the viewing chamber. The lamp 28 preferably is a high output daylight light of a known type.
In accordance with the invention, evaporative air cooling and humidifying means is provided for directing onto the encompassing perishable items supported in the viewing chamber with cooled and humidified air having a relatively high moisture content so as to maintain the items in a fresh and attractive condition during storage and display, while enabling direct access to and viewing of the vegetation. In the illustrated embodiment, air cooling and humidifying means 30 is contained within the cabinet 11 and includes a water reservoir 31 disposed in the bottom of the lower cabinet section 12-, an evaporative assembly 32 supported from a rear panel 34 of the cabinet section 12 and over-the reservoir 31 for pumping water onto the top of the evaporative assembly 32, and an electric fan 36 for drawing ambient air from the outside environment and through the evaporative assembly 32 and directing cooled and humidified air into the receiving chamber 20. The reservoir 31 is an open top water tank haying an appropriate water inlet line controlled by a float valve 38 of a known type which is adapted to
open when the water level lowers to a predetermined level and close when the water level again is raised to the desired upper level. The pump 35 is electrically operated and has a discharge line 39 coupled to a pair of fittings 40 on the top"side of the evaporative assembly 32.
. The evaporative assembly 32 includes a pair of evaporative elements or pads 45 supported by a casing 46 disposed about their outer perimeter. The evaporative elements 45 may be of a known type, such as disclosed in U.S. patent No. 2,955,064, which comprise a reticulate body of water impermeable material having a large surface area appropriately coated such that it is effective for bringing a large surface area of water in contact with air passing through the elements for producing rapid evaporation of the water.
For supplying water uniformly along the upper sides of the evaporative elements 45, distributor channels 48 are mounted at the top of the elements 45 in communication with the -respective fittings 40 and extend lengthwise substantially the length of the elements 45. The distributor channels 48 receive water directed through the. fittings 40 and are formed with appropriate longitudinally spaced openings through which water is fed from the distributor channel 448 onto-the top of the evaporative elements 45. The water then flows downwardly and spreads through the contact surface areas of the evaporative elements 45 in a substantially uniform manner with excess water reaching the bottom of the casing 46 and being returned to the reservoir tank 31 through drain openings 49.
The evaporative assembly 32 is supported in an inlet opening of a first plenum 50 mounted on the rear cabinet panel 34 which together define a first plenum chamber 51. The first plenum chamber 51 communicates with a second plenum chamber 52 defined between the panel 34 and a rearward-most panel 54 of the cabinet 11 through an opening 55 within which a blade of 36a of the fan 36 is disposed. The fan 36 in this case is mounted on the plenum 50. The second plenum chamber 52 extends upwardly from the lower cabinet section 12 into the rear portion 14a of the upper cabinet section 14 and has an outlet opening 60 communicating with the viewing chamber 20 substantially along its entire length. It will be seen that upon energization of the fan 36, air is drawn froπu the outside environment under the cabinet 11 and through the evaporative elements 45 where moisture is evaporated into the air, and then through the first plenum chamber 51. The air is then positively directed by the fan 36 into the second plenum chamber 52 and through the outlet 60 of the second plenum chamber.
In keeping with the invention, the evaporative cooling and humidification means is operable to cool and humidify the air passing through the evaporative assembly to a relatively high moisture level and then direct such cooled and humidified air onto the displayed perishables in a manner which substantially envelopes the perishables and shields them from the outside environment. To this end, the evaporative cooling and humidification means 30 is operated at a • relatively high evaporative efficiency such that ambient air (designated as Tl in FIG. 4) is humidified to a substantially saturated condition upon passage through the evaporative elements 45 (at
point designated T2 in FIG. 4) so as to achieve a relative humidity of about 90% with resulting cooling effects, and is discharged from the outlet 60 of the second plenum chamber 52 (at point designated T3 in FIG. 4) with a relative humidity of about 85%.
The cooling and humidification cyclically of operation of the illustrated display unit is more specifically depicted in FIG. 5. With the. temperature and relative humidity of the Outside ambient air designated Tl, as the ambient air passes through the evaporative elements 45, moisture in the evaporative elements 45 is evaporated into the air raising the relative humidity to a level near saturation, i.e., about 90%, thereby lowering the dry bulb temperature to a value T2 with the wet bulb temperature remaining constant, as shown in FIG. 5. Such dry bulb temperature T2 is only slightly greater than the lowest dry bulb temperature T4 that -could be achieved by such evaporative cooling, i.e., the dry bulb temperature when the relative humidity reaches 100% under the constant wet bulb temperature conditions. The evaporative efficiency of such operation, as depicted by the following formula based upon dry bulb temperatures, is thereby relatively high: actual cooling T1-T2
EVAPORATIVE EFFICIENCY = = x 100 max. possible T1-T4 cooling
It will be appreciated that the air generally will experience a slight temperature increase between point T2 (following passage through the evaporative elements 45) and point T3 (discharge from the outlet 60) by virtue of conditions existing at the outlet- 60, as well as any air leakage and warming effects
that occur in the plenum chambers 51, 52 communicating between the evaporative elements 45 and the outlet 60. In order to minimize such warming of the air between points T2 and T3, gaskets 62 preferably are provided between the casing 46 of the evaporative assembly 32 and the plenum 50, and insulation 64 is provided adjacent walls of the plenums.
For appropriately directing the humidified and cooled air from the outlet 60 onto the flowers supported within the viewing chamber, the outlet 60 is provided with a grill 60a which extends lengthwise along the rows of vases 26 and directs the air in a generally downward and forward direction so as to pass the air over the tops of the flowers 11 supported in both tήe rear and the forward rows of vases, thereby encompassing the flowers in a cooled and humidified environment which tends to preserve their freshness, as well as shield the flowers from the outside environment. The grill 60a preferably has movable slats so as to permit selective adjustment in the direction of the discharged air depending upon the sizes of the floral arrangements displayed within the viewing chamber. In order to enhance the uniform discharge of air along the length of the outlet grill 60a, a perforated carrier plate 66 is mounted in the plenum chamber 52 immediately adjacent the outlet 60 thereof. Such a perforated barrier plate 66 creates a relatively uniform pressure build-up along the entire length of the barrier and the outlet grill 60a_.
The following examples are illustrative of the operation of the storage and display unit 10 of the present invention at different ambient conditions Tl. In each case, the operating conditions are based
upon a storage unit in which the display shelf 16 is 52 inches wide and 19 inches deep and with a fan 36 that is operable to generate an air flow of between 170 and 200 c.f.m. It will be understood that in each case the examples are representative of" operating conditions, inasmuch as various- factors can affect the ambient conditions and air flow patterns about the storage unit and the viewing compartment.
EXAMPLE X
With the ambient air (Tl) having dry bulb temperature of 75°F and relative humidity of 50%, following passage of the air through the evaporative elements 45 the air (T2) is cooled to dry bulb temperature' of 64°F and humidified to a relative humidity of 94°. Upon discharge from the grill 60a, the air (T3) has a dry bulb temperature of 66?F and a relative humidity of 87%, which is directed over flowers contained within the viewing chamber 20 so as to maintain them in a fresh and relatively cool environment and shield them' from adverse effects of the outside environment. Since the maximum evaporative cooling (T4) of such ambient air, while maintaining a constant wet bulb temperature, would be a dry bulb temperature of 63°F, the evaporative efficiency of the evaporative assembly 32 in this instance is 92%, as depicted by the following formula:
Tl - T2 75 - 64
EVAP . EFF .- = x 100 = x 100 = 92%
Tl - T4 75 - 63
EXAMPLE II
With the ambient air (Tl) having a dry bulb temperature of 70°F and a relative humidity of 35%, following passage of the air through the evaporative elements 45, the air (T2) is cooled to a dry bulb temperature of 55.5°F and humidified to a relative humidity of 92%. Upon discharge from the outlet grill 60a, the air (T3) has a dry bulb temperature of 58°F and a relative humidity of 86%, which is directed onto the displayed vegetation. Since the maximum evaporative cooling (T4) of such ambient air would be a dry bulb temperature of 54°F, the evaporative efficiency of the evaporation assembly 32 operation in this instance is 91%.
EXAMPLE III
With the ambient air (Tl) having a dry bulb temperature of 80°F and a relative humidity of 20%, following passage of the air through the evaporative elements 45, the air (T2) is cooled to a dry bulb temperature of 58°F and humidified to a relative humidity of 90%. Upon discharge from the output grill 60a, the air (T3) has a dry bulb temperature of 60°F and a relative humidity of 85%, which is directed onto the vegetation iri the viewing chamber. Since the maximum evaporative cooling (T4) of such ambient air would be to a dry bulb temperature of 56°F, the evaporative efficiency of the evaporation assembly 32 in this case is 91%.
For the purpose of monitoring and controlling the evaporative air cooling and humidification means 30, a humistat 70 is mounted immediately adjacent the downstream side of the evaporative elements 45 and
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can be selectively set to a predetermined relative humidity level, such as 85%, so that in the event the relative humidity of the air at that point falls below such level, an indicator light 71 mounted on the front of the display unit is energized. It will be understood that the humistat 70 could be located at other locations, such as adjacent the discharge end of the outlet grill 10a, and set for the desired relative humidity level at point (T3), such as 80%.
From the foregoing, it can be seen that the storage and display unit of the present invention is completely open to the outside environment so as to permit easy viewing and inspection of flowers and vegetation contained therein, while providing an environment about the displayed items that preserves their freshness and beauty. The storage and display unit also is of relatively simple construction and is considerably more efficient and economical to - manufacture and operate than closed ref igerators heretofore commonly utilized for floral storage.
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