Site News  |   Monitor Keywords  |   Monitor Archive  |   Organizer  |   Account Info  |

Foul-resistant condenser using microchannel tubing

Foul-resistant condenser using microchannel tubing description/claims

This application claims priority from and the benefit of and is a continuation-in-part of co-pending U.S. patent application Ser. No. 11/255,426, filed Oct. 21, 2005, entitled FOUL-RESISTANT CONDENSER USING MICROCHANNEL TUBING, and published on Jul. 6, 2006, as U.S. Patent Publication No. 2006-0144076A1, which is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/835,031, filed Apr. 29, 2004, entitled FOUL-RESISTANT CONDENSER USING MICROCHANNEL TUBING, now U.S. Pat. No. 7,000,415.

This invention relates generally to refrigerated beverage and food service merchandisers and, more particularly, to a foul resistant condenser coil therefor.

It is long been the practice to sell soda and other soft drinks by way of vending machines or coin operated refrigerated containers for dispensing single bottles of beverages. These machines are generally stand alone machines that are plugged into standard outlets and include their own individual refrigeration circuit with both evaporator and condenser coils.

This self serve approach has now been expanded to include other types of “plug in” beverage and food merchandisers that are located in convenience stores, delicatessens, supermarkets and other retail establishments.

In such stores, cold beverages, such as soft drinks, beer, wine coolers, etc. are commonly displayed in refrigerated merchandisers for self-service purchase by customers. Conventional merchandisers of this type usually comprise a refrigerated, insulated enclosure defining a refrigerated product display cabinet and having one or more glass doors. The beverage product, typically in cans or bottles, single or in six-packs, is stored on shelves within the refrigerated display cabinet. To purchase a beverage, the customer opens one of the doors and reaches into the refrigerated cabinet to retrieve the desired product from the shelf.

Beverage merchandisers of this type necessarily include a refrigeration system for providing the cooled environment within the refrigerated display cabinet. Such refrigeration systems include an evaporator coil housed within the insulated enclosure defining the refrigerated display cabinet and a condenser coil and compressor housed in a compartment separate from and exteriorly of the insulated enclosure. Cold liquid refrigerant is circulated through the evaporator coil to cool the air within the refrigerated display cabinet. As a result of heat transfer between the air and the refrigerant passing in heat exchange relationship in the evaporator coil, the liquid refrigerant evaporates and leaves the evaporator coil as a vapor. The vapor phase refrigerant is then compressed in the compressor coil to a high pressure, as well as being heated to a higher temperature as a result of the compression process. The hot, high pressure vapor is then circulated through the condenser coil wherein it passes in heat exchange relationship with ambient air drawn or blown across through the condenser coil by a fan disposed in operative association with the condenser coil. As a result, the refrigerant is cooled and condensed back to the liquid phase and then passed through an expansion device which reduces both the pressure and the temperature of the liquid refrigerant before it is circulated back to the evaporator coil.

In conventional practice, the condenser coil comprises a plurality of round tubes with parallel fins extending between tubes across the flow path of the ambient air stream being drawn or blown through the condenser coil. A fan, disposed in operative association with the condenser coil, passes ambient air from the local environment through the condenser coil. U.S. Pat. No. 3,462,966 discloses a refrigerated glass door merchandiser having a condenser coil with staggered rows of finned tubes and an associated fan disposed upstream of the condenser coil that blows air across the condenser tubes. U.S. Pat. No. 4,977,754 discloses a refrigerated glass door merchandiser having a condenser coil with in-line finned tube rows and an associated fan disposed downstream of the condenser that draws air across the condenser tubes.

One problem that occurs with such self-contained merchandisers is that they are often in area that is heavily trafficked by people that tend to track in debris and dirt from the outside. This, in turn, tends to expose the condenser coil, which is necessarily exposed to the flow of air in the immediate vicinity, to be susceptible to airside fouling. With such fouling, the accumulation of dust, dirt and oils impede refrigeration performance. As the condenser coil fouls, the compressor refrigerant pressure rises, which leads to system inefficiencies and possibly compressor failure. Further, such products are often used in locations where periodic cleaning is not likely to occur.

The usual structure for such a condenser coil is a tube and fin design wherein a plurality of serpentine tubes with refrigerant flowing therein are surrounded by orthogonally extending fins over which the cooling air is made to flow by way of a fan. Generally, the greater the tube and fin densities, the more efficient the performance of the coil in cooling the refrigerant. However, the greater the tube and fin densities, the more susceptible it is to being fouled by the accumulation of dirt and fiber.

This problem has been addressed in one form by the elimination of fins and relying on conventional tubes as set forth in U.S. Pat. No. 6,851,271, assigned to the assignee of the present application and incorporated herein by reference. A further approach has been to selectively stagger the successive rows of tubes in relation to the direction of airflow as described in U.S. Patent Application No. (PCT/US03/12468), Continuation In Part Application of Provisional Application Ser. No. 60/376,486 filed on Apr. 30, 2002, assigned to the assignee of the present application and incorporated herein by reference.

U.S. Pat. No. 6,988,538 discloses a fin-and-tube condenser coil for use in connection with retail store refrigeration systems wherein the condenser coil includes a plurality of parallel flat microchannel tubes having zig-zag fins extending between adjacent flat tubes. The fin density ranges from slightly less than 12 fins per inch to slightly more than 24 fins per inch. The high fin density is possible because the condenser coil is generally position outside the store, such as on the roof-top, where the condenser coil is not exposed to a high level of dust and debris.

U.S. Pat. No. 6,912,864 discloses a refrigerated display merchandiser having a fin-and-tube evaporator formed of a plurality of parallel, flat microchannel tubes having V-shaped fins extending between adjacent flat tubes. The fin density ranges from as low as 6 fins per inch to as high as 25 fins per inch. The high fin density is possible because the evaporator coil is positioned internally within the rear air duct of the refrigerated merchandiser and therefore not exposed to a high level of dust and debris

In one aspect of the invention, a refrigerated merchandiser is provided having a condenser coil connected in refrigerant flow communication with an evaporator coil disposed in operative association with the display cabinet of the refrigerated merchandiser, wherein the condenser coil has a plurality of refrigerant carrying members aligned in generally parallel relationship and a plurality of fins connected in heat transfer relationship with and extending between adjacent members of the plurality of refrigerant carrying members, the plurality of fins being spaced apart at a spacing of at least 0.4 inches between adjacent fins. In one embodiment, the fins are spaced apart at a spacing of at least 0.6 inches. In another embodiment, the fins are spaced apart at a spacing in the range of 0.4 to 0.8 inches. In a further embodiment, the fins are spaced apart at a spacing in the range of 0.7 to 0.8 inches.

In one embodiment of the invention, the condenser coil has a plurality of fins extending generally orthogonally relative to said plurality of refrigerant carrying members and being disposed in generally parallel relationship. In another embodiment, the condenser coil has a plurality of generally V-fins being spaced apart at a spacing of at least 0.4 inches between adjacent fins as measured from apex to apex.

In one embodiment of the invention, the plurality of refrigerant carrying members of the condenser coil are flat tubes aligned in generally parallel relationship with each tube having a plurality of longitudinally extending channels that are fluidly connected at a first end to receive refrigerant flow from an inlet header and at a second end to discharge refrigerant flow to an outlet header. In another embodiment of the invention, the plurality of refrigerant carrying members is a serpentine tube having a plurality of flat tube segments aligned in generally parallel relationship with adjacent tube members being interconnected at their respective ends to form a serpentine refrigerant flow path. The serpentine tube has a plurality of longitudinally extending channels that are fluidly connected at a first end to receive refrigerant flow from an inlet header and at a second end to discharge refrigerant flow to an outlet header.

In another aspect of the invention, a refrigerated merchandiser is provided having a condenser coil connected in refrigerant flow communication with an evaporator coil disposed in operative association with the display cabinet of the refrigerated merchandiser, wherein the condenser coil includes at least one serpentine shaped refrigerant tube having a plurality of flat segments aligned in generally parallel relationship, the plurality of flat segments being spaced apart at a spacing of at least 0.4 inches between adjacent flat segments. Each of the flat tube segments of the serpentine shaped refrigerant tube may include a plurality of longitudinally extending channels providing a corresponding plurality of refrigerant flow passages, which may be minichannel or microchannel flow passages. In one embodiment, the flat tube segments are spaced apart at a spacing of at least 0.6 inches between adjacent flat segments. In another embodiment, flat tube segments are spaced apart at a spacing of at least 0.4 to 0.8 inches between adjacent flat segments. In a further embodiment, the flat tube segments are spaced apart at a spacing of at least 0.6 inches between adjacent flat segments.

In one aspect of the invention, a refrigerated merchandiser is provided having a condenser coil connected in refrigerant flow communication with an evaporator coil disposed in operative association with the display cabinet of the refrigerated merchandiser, wherein the condenser coil has a plurality of refrigerant carrying members aligned in generally parallel relationship and a plurality of fins connected in heat transfer relationship with and extending between adjacent members of the plurality of refrigerant carrying members in a zig-zag arrangement, that is a generally V-shaped pattern, with the plurality of fins being spaced apart at a dimension, w, as measured from apex to apex, of at least about 0.4 inches. In one embodiment, the fins are spaced apart at a spacing of at least 0.6 inches. In another embodiment, the fins are spaced apart at a spacing in the range of about 0.4 to about 0.8 inches.

In another aspect of the invention, a refrigerated merchandiser is provided having a condenser coil connected in refrigerant flow communication with an evaporator coil disposed in operative association with the display cabinet of the refrigerated merchandiser, wherein the condenser coil has a plurality of refrigerant carrying members aligned in generally parallel relationship and a plurality of fins connected in heat transfer relationship with and extending between adjacent members of the plurality of refrigerant carrying members in a zig-zag arrangement, that is a generally V-shaped pattern, with the plurality of fins being spaced apart at a dimension, w, as measured from apex to apex, in range of from about ⅓ inches to about ½ inches.

• Provisional Patent
• Utility Patent

• What Is a Patent?
• What Is a Trademark or Servicemark?
• What Is a Copyright?
• Patent Laws