초록 ▼

A commercial refrigerated display case, of the type in which an air curtain is directed across an upwardly opening product display space, utilizes ambient air for defrost purposes. A discharge sill extending along the back of the case, above the discharge grille through which air is directed to form

A commercial refrigerated display case, of the type in which an air curtain is directed across an upwardly opening product display space, utilizes ambient air for defrost purposes. A discharge sill extending along the back of the case, above the discharge grille through which air is directed to form the air curtain, is hollowly formed to provide a defrost air chamber. Within the chamber defrost air fans are mounted and are normally off during the refrigeration cycle of the display case. During defrost, the air circulating fan continues in operation although the evaporator coil is no longer in a refrigeration mode. At the same time the defrost fan goes into operation, and draws off part of the air circulated through the discharge grille by the main fan, and exhausts it to ambient through the discharge sill. A weak air curtain is still maintained across the access opening of the display case. Drawing off part of the air through the discharge grille, while continuing operation of the main fan, causes at least a substantial part of the air drawn through the return opening to be obtained from the surrounding ambient, so as to swiftly defrost the evaporator.

대표청구항 ▼

In a low-bed refrigerated display case having rear, bottom, and front walls providing a product well at the top of which an access opening is defined, the walls further providing an air passage that extends about the product well and a discharge grill and a return opening extending along the rear an

In a low-bed refrigerated display case having rear, bottom, and front walls providing a product well at the top of which an access opening is defined, the walls further providing an air passage that extends about the product well and a discharge grill and a return opening extending along the rear and front edges, respectively, of the access opening, an evaporator coil in the passage, and a circulating fan also mounted in the passage to circulate air through the passage and coil and form an air curtain in movement across access opening from the discharge grill to the return opening during the refrigeration mode of the case, the improvement comprising a discharge sill mounted on the rear wall above the outlet, the sill having a defrost air chamber to which entry is had through inlet ports located adjacent the discharge grille, and from which air may be discharged through outlet ports to the ambient atmosphere surrounding the case; and defrost air fan means mounted in the chamber and adapted for operation during a defrost mode in a direction to draw air into the chamber through the inlet ports and discharge it through the outlet ports, in a quantity such that at least part of the air exiting the discharge grille is discharged through the sill to the surrounding ambient and thereby diminishes the air curtain voluntarily to an extent effective to induce at least some ambient air to enter the return opening.