Refrigeration – Gas controller or director – Gas forcing means – e.g. – cooler unit
Reexamination Certificate
2003-10-20
2004-07-20
Jones, Melvin (Department: 3744)
Refrigeration
Gas controller or director
Gas forcing means, e.g., cooler unit
C062S129000, C062S176100, C062S440000
Reexamination Certificate
active
06763677
ABSTRACT:
BACKGROUND OF THE INVENTION
Container refrigeration units are controlled by a microprocessor which receives inputs indicating the temperature, humidity, etc. in the conditioned space and controls the refrigeration system responsive to the inputs. Additionally, the microprocessor records the inputs such that the history of the load during the trip is recorded. Accordingly, it is possible to determine when and why a load is spoiled, thawed or the like. Perishable cargo such as fruit, vegetables and flowers produce, and are affected by, gases. Ethylene, for example, is produced in the ripening of bananas and its presence promotes ripening. It is therefore necessary to introduce some fresh air with the recirculating air, where perishable cargo is present, if spoilage or premature ripening of the load is to be avoided.
In a container, the load normally occupies all of the available space such that the flow paths for the conditioned air are located in the floor, ceiling and walls of the container and are often at least partially defined by the load. To minimize the wastage of conditioned space, only the expansion device, the evaporator, the evaporator fan, necessary ducting and sensors are located in the conditioned space. The rest of the refrigeration unit and its controls are located on the exterior of the container and are powered by an external power supply.
SUMMARY OF THE INVENTION
In the present invention a manually operated fresh air vent is provided to introduce some ambient/fresh air into the air circulating in the container and to exhaust some air from the container such as is done to provide some fresh air in commercial buildings. When the temperature setting is above freezing, or another temperature indicative of a perishable load, the condenser fan is run continuously independent of the operation of the refrigeration system when the fresh air vent is open. The fresh air vent position sensor of the present invention continuously senses the position of the fresh air vent in the refrigeration container unit. The microprocessor based controller of the refrigeration container unit automatically records the time and position of the fresh air vent as well as the evaporator fan speed. In a preferred embodiment, mechanically keyed tangs transfer mechanical movement of the fresh air door to a rotary electronic sensor such as a sealed Hall effect sensor. The rotary electronic sensor has a output voltage proportional to its mechanical position and its output voltage is used by the controller to determine the position of the fresh air vent door. Relative to the fresh air vent, the microprocessor stores the manual vent position change, the trip start vent position, the power on vent position and the midnight or other periodic logging of the vent position.
It is an object of this invention to monitor the opening, closing and position of a manually actuated vent.
It is another object of this invention to selectively provide a continuous supply of fresh air to a perishable cargo.
It is a further object of this invention to provide a sensor which cannot be improperly assembled as to its position and requires no mechanical calibration. These objects, and others as will become apparent hereinafter, are accomplished by the present invention.
Basically, a refrigeration container is provided with a manually operated fresh air vent with a position sensor which provides a signal to the microprocessor based controller indicative of the position of the fresh air vent. The fresh air vent controls both the providing of fresh air to the circulating air in the container and the exhausting of a portion of the circulating air. The evaporator fan is run continuously when the air vent is open to prevent the build up of gases produced by the perishable cargo.
REFERENCES:
patent: 5369957 (1994-12-01), Hanson
patent: 5743109 (1998-04-01), Schulak
patent: 5899083 (1999-05-01), Peterson et al.
Burchill Jeffrey J.
Heffron William J.
Vivirito Lawrence J.
Carrier Corporation
Jones Melvin
LandOfFree
Fresh air vent position monitoring system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fresh air vent position monitoring system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fresh air vent position monitoring system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3248572