Refrigeration – Processes – Circulating external gas
Reexamination Certificate
2000-01-28
2002-11-19
Tapolcai, William E. (Department: 3744)
Refrigeration
Processes
Circulating external gas
C062S271000
Reexamination Certificate
active
06481222
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a method and apparatus for both humidification and dehumidification through the use of desiccant materials, as well as the automatic regulation of the relative humidity of the air contained in motor powered vehicles (hereinafter “motorized vehicles”), and the efficient automatic elimination and prevention of frost, fog, or condensation on the inside of the window glass of vehicles, and the elimination and prevention of frost in refrigeration units.
2. Description of the Related Art
The invention provides features and benefits by controlling relative humidity in a way not previously available. Automobiles, trucks, vans, trains, boats, ships, military vehicles, aircraft, tractors, motorized recreation vehicles, and various other types of motorized vehicles have previously lacked a successful and economical method or apparatus to automatically monitor and control the relative humidity within the cabin of the vehicle.
Previously produced motorized vehicle environmental systems have been developed to increase or decrease the cabin air temperature, regulate the rate of air flow, filter dust or pollen particles out of the air, defrost/defog the windshield, or reduce cabin noise, but none of the environmental systems have attempted to economically and effectively regulate the relative humidity level of the cabin air. Although the environmental systems in some over the road trucks have utilized water humidification and various dehumidification methods in the past, the systems were either inefficient, unhealthy, or expensive due to their initial installation cost, maintenance requirements, or their high level of energy consumption. There are currently desiccant based dehumidification systems for commercial buildings, however, they do not use the same processes or methods to provide a heat source for regeneration or the same configuration of desiccant wheel that is used as an element of this inventive method and apparatus, and none employ a canister like that shown and claimed.
Traditional refrigeration and freezer units produce frost or condensation within the box or on the evaporator coils when the humidity of the air reaches the saturation point as the air is cooled in the unit. The inherent frost problem restricts the air flow over the coils, creates a frost buildup on the inside of the box, and limits the efficiency of the coils. The current methods of defrosting these types of units use additional energy and utilize expensive apparatus to remove the frost.
In previously manufactured motorized vehicles the relative humidity of the cabin has essentially been unmonitored, unregulated and uncontrolled except through the use of traditional air-conditioner evaporator units. The lack of humidity control of the cabin air in motorized vehicle can have a negative effect on safety, comfort, health, and operating efficiency.
In motorized vehicles the need for an efficient and effective way to increase the relative humidity in the cabin to improve the comfort for the occupants has existed for many years. If the motorized vehicle is operating in cold weather without the addition of humidity into the cabin air, the continued use of the heater in combination with the introduction of cool dry fresh air from outside will cause the relative humidity in the cabin to decrease to a point where the occupants may become uncomfortable. Traditional humidification units have experienced many problems due to the need to haul water and health hazards are present from the growth of bacteria, mold and mildew in the system.
In aircraft the problem is compounded because of the long duration of the flight and the extremely low levels of humidity that occurs in aircraft. In most long range commercial aircraft the cabin environmental system is heated by compressed air taken from the compressor section of the turbine engine. Outside air enters the engine air intake, is compressed and thus heated by the compressor section of the engine. Some of the hot compressed air going through the engine is vented off from the engine prior to the air entering the burner section of the engine. The hot air is then forced into the cabin environmental system.
During most flights, the outside air has a low relative humidity before it is heated, and the result of heating the air produces an extremely low relative humidity when the air enters the cabin. Even the moisture given off by evaporation from the occupant's perspiration and from evaporation of moisture out of the occupants lungs is not sufficient to keep the cabin at a high enough relative humidity for it to be comfortable to the occupants. The moisture given off by the occupants and generated from other sources escapes out of the cabin as the stale cabin air is expelled from the cabin. Although the cabin of a commercial aircraft may have the temperature regulated very close to 70° F., the relative humidity can drop to well below 20%.
The CO
2
in the cabin can cause discomfort for the occupants when the CO
2
reaches levels greater than 1000 ppm (parts per million). This high level of CO
2
exist because of the low percentage of new fresh air brought into the cabin as compared to the ratio of old stale air recirculated. The ratio of the fresh air is inadequate to replace enough of the unwanted CO
2
. If the environmental system circulates in more fresh air from outside to reduce the ratio of CO
2
and increase the ratio of Oxygen, the resultant air mass would have an even lower relative humidity. This would produce a relative humidity level even lower than the current uncomfortable levels of less than 20%.
These extreme conditions cause the passengers to experience substantial discomfort caused by two factors: 1.) stuffy feeling from poor ventilation of fresh air; and 2.) dryness from extremely low relative humidity. The effects of these two factors manifest in the physiological conditions for the occupants as respiratory irritation, headaches, and fatigue. These same factors also effect the flight crew and impact the safe operation of the aircraft due to the crew member's distraction from the effects of high CO
2
and low relative humidity.
In aircraft design, there has always been strong economic pressure to reduce the operational cost by reducing the cost of fuel. The weight of the aircraft has a direct relationship to the consumption of fuel. For each pound of cargo which must be reduced to off set an additional pound of aircraft weight there is a penalty due to the loss of revenue for the pound of cargo and the additional cost of fuel to transport the extra weight added to the aircraft. If an inventive apparatus is installed in the aircraft, the weight of the apparatus is added to the total air frame weight. Of course, the additional weight of the apparatus will have a long term operational cost disadvantage simply due to the weight of the apparatus installed in the aircraft. The benefits of passenger comfort must off set the cost penalty of initial unit cost and long term operational fuel cost. The cost benefit of lower aircraft weight due to the conditioning of the air in the cabin is a respectable trade-off.
It is commonly understood that water is heavier than air. What is not commonly understood is that water vapor is lighter than air. Since the inventive apparatus adds water vapor to the air contained in the cabin the apparatus is actually reducing the weight of the aircraft by reducing the weight of the cabin air. Air is made up of: NITROGEN 78% (NI) with 14.0067 AMU (Atomic Mass Units); OXYGEN 21% (0) with 15.9994 AMU and OTHER GASES 1% which consist of: ARGON 0.9%, CARBON DIOXIDE 0.03% and varying amounts of WATER VAPOR Since CARBON has an AMU of 12.011 the combined molecule of CARBON DIOXIDE with CARBON: 12.011 and OXYGEN: 15.9994 is actually lighter than OXYGEN alone with 15.9994. This would provide the designer with a marginal incentive to increase the CARBON DIOXIDE content in the air mass of the cabin to reduce the aircraft weight. When OXYGEN 15.9994 is c
Beavers Lucian Wayne
Tapolcai William E.
Waddey & Patterson
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