US20100275621A1

Movatterモバイル変換

Info

Publication number: US20100275621A1
Application number: US12/747,006
Authority: US
Inventors: Jose Vilani Oliveira, JR.
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-12-10
Filing date: 2007-12-10
Publication date: 2010-11-04
Also published as: WO2009073937A1; EP2219438A4; EP2219438A1

Abstract

A dehumidification or dehydration Unit is comprised by a coil or heat exchanger of evaporation (1), a coil or heat exchanger of condensation (2), an expansion valve (3), a rejected heat air stream (4) by the condensation coil (2), a compressor (5) or another equipment for increasing pressure, a ventilator (6) is provided for rejection of heat to environment from the parts of the condensation coil (2) and a circuit or substance (7) that is to be dehydrated or demisted. A ventilator unit (8) for recirculation of air and a gutter (9) for collection of condensate in the coil, which is collected by the condensate drain (10), are also provided. An air duct (12) is provided for rejection of heat. The condensation coil (2) is divided by a border or wall (16), to use part of the heat for the reheating of the cold and dry air.

Description

The present patent of invention has as objective an equipment or system to extract the humidity or the water contained in environments, circuits, products or systems, in closed or opened cycle.
It is already known and widely used dehumidifiers, driers or dehydrators of environments, ovens, circuits, products or systems, that basically consist of environment heaters or ovens, either for electric resistance, heat exchanger with warm fluid in its interior, cycle of heat pump or inverted cycle of refrigeration. All these systems or circuits raise the temperature of air and, consequently, they diminish the relative humidity, generating a vapor pressure for the warm fluid and increasing the capacity of this fluid, normally air, to absorb more water of the environment, circuit or system. This type of dehumidification has as great inconvenience the temperature higher than of the environment, which causes irreversible losses of thermosensible substances, properties, vitamins and proteins. In the case where in this environment there are people, as in laboratories and clean rooms, the thermal discomfort caused by the heat would be very great. Another state of the art is the dehumidification or dehydration of air through the condensation of the water contained in this air of the circuit, system or volume of control, through the use of the refrigeration or heat exchanger with frozen water or a frozen fluid, where the reduction of the temperature below of the dew point is promoted, in this manner the water vapor contained in air condenses, lowering the absolute humidity or the amount of water per air volume. Normally, this cooled air has to be warmed to diminish the relative humidity and thus to get dry air. To return this air to the ambient temperature, of comfort or work, normally an electric resistance or a heat exchanger with hot water or another hot fluid is used. Considering this situation energy is spent twice, one to cool the air and another one to heat it, once usually there are independent systems to perform this function. Moreover, expensive systems of instrumentation and control of temperature are necessary for the correct adjustment and control of the system.
Another type of dehumidifier, dehydrator or drier is the chemical type through cylinder or rotating wheel of a hygroscopic or highly desiccant element, in some cases lithium chloride—ClLi or Silica gel. The principle of functioning of this widely used equipment for humidity control in controlled environments consists of a transversal section of the wheel or cylinder where there is the humid airflow passage, and in another section it is the airflow passage of regeneration or reactivation of the desiccant element. The process is continuous in regeneration or reactivation as well as in the dehumidification, once as the wheel or cylinder turns, there will have a section ready to absorb humidity while a humid section exists that is being regenerated. The process consists of an airflow to be dehumidified that it is forced to permeate the desiccant element of the section of the wheel or cylinder, causing the water to be absorbed by the hygroscopic element, where the air is left dry, with decreased relative humidity. The water absorbed for the wheel or cylinder needs to be removed of the impregnated chemical element so that it can receive again humid air when to reach the dehumidification section. Regeneration or reactivation occurs in another section of the wheel. Normally a warm external airflow at high temperature and raised airflow are used in the regeneration of the desiccant element. Normally, it is necessary a heat exchanger warmed by vapor and a fan insufflating air. The inconvenience of this system is the high cost of operation and installation, besides needing high investment in equipment, systems, accessories and control, besides utilities as boiler to generate vapor.
PI9303857-7 deposited in the INPI, whose title Dryer-Dehumidifier of grains, leaves and fruits, uses in the same system and in series, the process of condensation of water vapor contained in air through the coil of the evaporator of the refrigeration cycle and, after that, the process of heating the air, with the reuse of all heat generated for the condensation coil of the same cycle and for the compressor. In this manner, water condenses in the evaporation coil and diminishes the absolute humidity. The heating of the cold and dehumidified air flow occurs in the condensation coil and the compressor. This system, differently of the previous ones, reuses the heat, which normally would be totally rejected for the environment, to heat the dehumidified air, lowering the relative humidity for raising the temperature of air.
All system or refrigeration cycle removes heat of one environment (hot source) and needs to reject this heat to other environment (cold source), according to Law of the Thermodynamics. This function of rejecting the heat is made by the condensation coil and, it is added to the removed heat of the environment (hot source), the energy supplied for the compressor and a small quantity of energy generated due to internal frictions. The heat has to be rejected so that the system or refrigeration cycle can again remove the heat of the hot source, closing the cycle. Obviously, there is the need of rejecting this calorific energy for another environment, and that it is not the same environment that is being cooled.
In the proposed process of the application PI9303857-7 cited above, the addition of the calorific energies of the environment to be dehumidified/refrigerated occurs in the circuit of the system, with the calorific energies of the compressor and with a small worthless quantity promoted by friction. As no rejection of heat occurs and as the time goes by, more energy is added to the system due to the continuous work of the motor-compressor. Inevitably, this addition of calorific energy of the system will cause the heating of the air that passes through all the set. This system becomes a heat pump instead of a refrigeration cycle. Even for the pump cycle works, it is necessary to reject a quantity of heat for a cold source. Therefore, there is the need for a cold or ambient air input for mixture with the air of the system, lowering the temperature of the system and rejecting heat. In this manner, the system is not closed anymore causing inconveniences when foods, spores, honey and other substances or products are dehumidified, due to the highest risk of air contamination of the system by the external air, and consequently, of the product to be dehumidified or dehydrated, despite the inevitable heating. Normally, this high temperature is controlled with a thermostat to turn off the compressor and, to cause an interruption in the process, intermittent without temperature uniformity, lowering the yield. Depending on the dimensions of the equipment, a great oscillation in the system with delayed time of answer occurs due to the long time of stopping of the refrigeration/dehumidification cycle, resting only the forced ventilation activated.
Even considering the wide use of these types of dehumidifiers, driers and dehydration units, some inconveniences can be attributed to them, as for example the loss and deterioration of thermosensible proteins, vitamins, spores, enzymes and substances or products, modification of the organoleptic characteristics, evaporated or burnt vitamins, substances and proteins, contamination of the air of the circuit or system by external air, besides the high cost of operation, maintenance and acquisition. In the apiculture, in special with the honey, the exposition to high temperatures causes the irreversible rising of Hydroximethylphurphural (HMF), ending up with an acidic honey. The legislation, not only the Brazilian as the foreign one, stipulates the maximum parameters of Hydroximethylphurphural in the honey. In case where it is above of a established value the honey must be discarded or this honey of inferior quality will be mixed with one of superior quality, lowering the quality of the final product. Some honeys need to be dehumidified once the legislation obliges that the honey must be commercialized with relative humidity inferior of 18%. Moreover, honeys with more than 20% of relative humidity have greater potential of fermentation. Some harvests of honey are harvested from 20% to 23% of RH and, some will be mixed other honeys with lower content of relative humidity, in this manner harming the honey with low humidity and superior quality and price, lowering its market value. One technique to dehydrate the honey uses dehumidification with hot and dry airflow, what increases the honey temperature and increases the level of HMF irreversibly. Another used technique is dehumidification with environment refrigeration where the product is stored. It is very long process once the exchange area is small, unhygienic once the honey is exposed to an environment susceptible to dust and dirtiness. Another great inconvenience is the acceleration of the process of crystallization of the honey, which occurs at low temperatures. Currently it is estimated that 25% of the honeys harvested in Brazil have relative humidity above 18%.
The dehydration of pollen, which is a product that necessarily has to be dehydrated, must be performed in order of not creating fungi and mildew. As the honey, this process must occur as close as possible to the ambient temperature in order of not to break volatile enzymes, to modify the original characteristics and loss of thermosensible proteins and vitamins as vitamins A and E, amongst others. The equipment traditionally used to dehydrate the pollen is the oven, which heats the product and has as inconvenient the cited ones above.
Research laboratories, for example, need to dehydrate thermosensible spores and other substances and products for tests and research, for medicaments and compounds formulations, and others. Beside the risk of the partial or total loss of these substances by the heat, there is the risk of contamination of the substance itself not only by the external air but also of the environment by the substance; in case of it is harmful.
Taking these problems into account and with the intention of surpassing them a new system of dehumidification or dehydration was searched and developed, objective of present application, which possesses a fundamental difference and which consists of effecting the calculation and the thermal balance between the heat removed for the evaporation coil, the heat in the condensation coil, the amount of heat that needs to be rejected for the environment, the latent and sensible heat of dehumidification, initial and final temperatures of the desired airflow, using to advantage only one quantity conveniently calculated of the condensation coil for reheating the dry and cold air, and rejecting for the environment the heat in excess.
This form of construction of the system or equipment to dehumidify solves all the cited inconveniences, once only a convenient calculated part of the condensation coil is used to heat the dry and cold air, to reach the desired temperature and low levels of relative humidity. Besides of propitiating the best energy exploitation of the cycle, not only in terms of energy but also heat.
The principle of dehumidification or dehydration of the dehumidification unit, not only for a closed circuit system as for an opened one, is the same. If it is for a closed circuit, the airflow is dehumidified in the dehumidification or dehydration unit, goes to the place where is desired to keep the controlled humidity low, gains humidity, returns to the dehumidification unit, leaves water in the unit and restarts the cycle. In the case of open system the air or an amount of it is admitted in the dehumidification unit and goes for another environment returning partially or not. The principle of functioning of the dehumidification or dehydration unit, subject-matter of the present application, consists of the passage of the humid airflow for the evaporation or cold coil, where occur the dehumidification or drying of air or another gaseous fluid through the cooling of this fluid below the dew point temperature, forcing the condensation of the humidity or of the water vapor promoted by the passage for a cold coil or cold heat exchanger of evaporation of the refrigeration cycle, being the water condensed, removed or eliminated for a reservoir while the dry and cold air is then forced for passing for a part, conveniently calculated and adjusted of the coil or heat exchanger of condensation or hot of the same refrigeration cycle, where the dry and cold air or fluid is sufficiently and conveniently warmed, reusing part of the heat that would be rejected by the refrigeration cycle and producing dry air with low relative humidity, in order to take into account the requirements of dehumidification or drying of the place, environment, circuit, chamber, system, substance, food or product, amongst others, being that the reheated dry air or fluid reaches low relative humidity at temperatures above of its dew point, using the residual heat of the refrigeration cycle, that was not reused to heat the dry and cold air, that is rejected for a colder environment than the hot condenser or coil, and independent of the dry and dehumidified airflow, without the flow crossing and the contaminating of the place, circuit, chamber, system, substance, food or product, amongst others, being the rejection of the heat of the refrigeration cycle not used to advantage in the reheating of the dry and cold air, that occurs through another part or another coil or condensation or hot heat exchanger, keeping the system balanced thermally, continuous, without functioning interruptions and taking into account the Laws of the Thermodynamics.
The dehumidification unit with two condensation coils can also be constructed conveniently calculated and adjusted so that one works dedicated to reject the produced heat of the refrigeration circuit for the environment and the other coil dedicated for the heating or reheating of cold and dry air.
This system has as great advantage the fact of being continuous, due to the fact that once adjusted, determined or calculated the proportion or size of the condensation coil to effect the desired heating of cold and dry air, the dehumidification occurs without interruptions. According to the need of the final temperature of dry air, the area of exchange of the condensation coil can be adjusted, and consequently, the amount of heat that is yielded by it to the dry airflow. One of the applications of this dry air to the ambient temperature is its use in towers, closed chambers, circuits, clean areas without the necessity of external air addition, where the product that one desires to dehumidify is placed, diminishing the contamination risk.
The dehumidification process is as follow: dry air permeates the product or substance and due to differential pressure of water vapor, the substance, with greater humidity, and air with low humidity, releases the water to the dry air, extracting humidity of it. A relevant aspect and that must be obeyed so that the system functions in equilibrium, is to reject the heat for the environment of the remaining part and not used of the condensation coil for a fan or airflow. The use of a part or section of the condensation coil to promote sufficient air heating is the great advance resulting in a better energy exploitation in face of the use of part of the heat normally rejected for the environment by the refrigeration cycle to heat the cold air of the closed circuit, getting the maximum exploitation, performance and yield of the refrigeration cycle. There is an energetic gain in this system once energy is saved when maximizing the energetic use reducing the rejection of heat to the minimum as possible for the continuous functioning of the system.
On the other hand, the new constructive aspect makes the dehumidification unit simpler and more compact, once the condensation and evaporation coils are placed face to face, simplifying the assembly and maintenance.
In the tests carried out with pollen using this new dehumidification, dehydration or drying process, subject-matter of the present application, the dehumidification unit was much more efficient in the maintenance of vitamin contents if compared with the traditional equipment of drying with oven (heating), as the MU7201461-0, AUTOMATIC POLLEN DRIER AND HONEY DEHUMIDIFIER. The results of the tests of the Dehumidification Unit for the maintenance of the vitamin A after the drying was superior about 47%, in more than 22% for the vitamin E and, and more than 100% for vitamin C, when compared with the traditional process of drying with oven, with the reduction also in the losses of thermosensible proteins. The drying time or dehumidification was faster about 20%, diminishing the processing time and saving energy. Therefore, the performance of this new system is superior in all aspects comparing with the traditional process.
In the honey case, the tests carried out with the DEHUMIDIFICATION OR DEHYDRATION UNIT, all the natural characteristics of the product were integrally kept, without modification after the dehydration. The levels of HMF, organoleptic properties, enzymes, vitamins and sugars had not gotten altered in all the samples, while the conventional processes modify significantly the product. The best maintenance of the properties and characteristics of the product during the drying also occurred with other foods, fruits and substances dehumidified with this new equipment and process. This equipment is of vital importance for the increase of the exportations and production of honeys as well as of the proper domestic commercialization taking care of the demanded standards of quality in Brazil and the exterior. The DEHUMIDIFICATION OR DEHYDRATION UNIT can also be used in the dehydration or drying of spores, fruits, foods, mushrooms, other products and substances, environments, seeds, grains, medicaments and compounds formulations, amongst others, once it will be able to promote the dehumidification or dehydration in a less aggressive way and with less degradation of the dehydrated substance or product, when compared with dehydration processes that use heat.

The attached drawing schematically shows the disposal of the parts that constitute the dehumidification unit, objective of the present application in which:

FIG. 1 shows the schematic view of the system.

According to as much is illustrated in the related FIGURE above, the dehumidification or dehydration unit, subject-matter of the present application, consists of a coil or heat exchanger of evaporation or cold (1), coil or heat exchanger of condensation or hot (2), expansion valve (3), airflow of rejected heat (4) through the condensation coil (2), compressor or another equipment for increasing pressure (5), fan for heat rejection to the environment of the part of the condensation coil (6), environment, chamber, circuit or substance that will be dehydrated or dehumidified (7), fan of air recirculation of the unit (8), gutter for condensate collect (9) formed in the evaporation or cold coil (1), where the condensate will be collected by the drain (10), duct of return of humid air (11), air duct of heat rejection (12), air inlet (13) for heat rejection, dividing wall or border of the condensation coil (16), temperature sensor (14) of the environment or chamber, connected to the duct of dry air (15).

Dry air coming from the duct of dry air (15) permeates the product or substance that is in the chamber or environment (7) and due to differential pressure of water vapor, the substance, with greater humidity, and the dry or with low humidity air, cedes the water to the dry air, extracting the humidity and drying the product. The humid air leaves the chamber (7), goes through the duct of humid air (11) to the recirculation fan of air (8). The humid air meets the evaporation or cold coil (1) and due to the temperature, that must be lower than of the dew point of this air, the water vapor contained in this air condenses and is collected by the gutter (9) and the condensate is collected by the drain (10). The cooled air goes now to the condensation or heating coil (2) where it gains heat to reach the desired temperature and enters in the duct (15) dried, being able to reach in some conditions 0% of relative humidity at ambient temperature. The dividing border or wall (16) of the condensation coil (2), divides this coil in such a manner that part of the heat, previously known, is used to heat the cooled air and the remaining part is rejected to the environment by the airflow (4) that comes by the duct (12) impelled by the fan (6) for air admission at external ambient temperature by the air inlet (13). Dry air returns to the initial point by the duct (15) to again removing the humidity of the substance or product in the chamber or environment (7). The sensor of temperature (14) can be used to verify the temperature of the process, to control and to adjust the border or wall (16) to control the amount of heat admitted for temperature balance. This control can be automatic or manual.

When is desired to work at constant temperature, constant operation conditions, for the same substance or for a substance or product whose characteristics do not vary much, the border or wall (16) can be fixed or the Dehumidification Unit can be configured to operate with two condensation or hot coils conveniently calculated and dimensioned, respecting the same configuration of assembly previously presented and the thermal balancing of the refrigeration circuit, being one mounted in the duct of dry and cold air (15) in front of the evaporation or cold coil (1) and the other coil mounted in the air duct of heat rejection (12), both the coils in series in the refrigeration circuit. With this, it is eliminated the dividing border or wall (16) since the coils are independent and the ducts play the role of dividing wall.

Logically, the dehumidification or dehydration unit can be obtained in several sizes, capacities and action to take care of the necessities of the users of this type of equipment. Besides being able to work with several types of refrigeration systems as, for example, water frozen vulgarly known per “chillers”, or compression of gases, among others. The Dehydration or Dehumidification Unit, depending on the refrigeration system utilized possesses all the controls, sensors and security systems for the perfect functioning of the unit.

For applications where great capacities is needed, several Dehumidification Units can be configured in series or parallel, depending on the necessity.

Claims

1-14. (canceled)

15. Dehumidification or dehydration unit for apicultural use, comprised by a coil or heat exchanger of evaporation or cold, coil or heat exchanger of condensation or hot, expansion valve, airflow of rejected heat by the condensation coil, compressor or another equipment for increasing pressure, fan for heat rejection to the environment of the part of the condensation coil, environment, chamber, circuit or substance that will be dehydrated or dehumidified, fan of air recirculation of the unit, gutter for condensate collect formed in the evaporation or cold coil, where the condensate will be collected by the drain, duct of return of humid air, air duct of heat rejection, temperature sensor of the environment or chamber, connected to the duct of dry air, air inlet for heat rejection, characterized for the fact of having a dividing wall or border of the condensation coil to use part of the heat of the condensation coil or hot for the reheating of the cold and dry air.

16. Dehumidification or dehydration unit for apicultural use, in accordance withclaim 15, characterized for possessing adjustment in the dividing border or wall.

17. Dehumidification or dehydration unit for apicultural use, in accordance withclaim 15, characterized for possessing a fixed dividing border or wall.

18. Dehumidification or dehydration unit for apicultural use, in accordance withclaim 15, characterized for possessing two coils or heat exchangers of condensation or hot, one being dedicated to the reheating of cold and dry air, and the other dedicated to reject heat for the environment.

19. Dehumidification or dehydration unit for apicultural use, in accordance withclaim 15, characterized for possessing several coils or heat exchangers of condensation or hot, being part of the coils dedicated to the reheating of cold and dry air, and another part to reject heat for the environment.

20. Dehumidification or dehydration unit for apicultural use, in accordance withclaim 15, characterized for possessing several coils or heat exchangers of evaporation or cold.

21. Dehumidification or dehydration unit for apicultural use, in accordance withclaim 15, characterized for working with several dehumidification units in series.

22. Dehumidification or dehydration unit for apicultural use, in accordance withclaim 15, characterized for working with several dehumidification units in parallel.

23. Dehumidification or dehydration unit for apicultural use, in accordance withclaim 15, characterized for working in opened circuit.

24. Dehumidification or dehydration unit for apicultural use, in accordance withclaim 15, characterized for working in closed circuit.

25. Use of a dehumidification or dehydration unit, in accordance withclaim 15, characterized for dehydrating pollen, honey and its derivatives.

26. Use of a dehumidification or dehydration unit, in accordance withclaim 15, characterized for dehydrating spores, fruits, foods, mushrooms, other products and substances, environments, seeds, grains, medicaments and compounds formulations, amongst others.

27. Process of dehumidification or dehydration of air or other gaseous fluid in a dehumidification or dehydration unit, characterized for dehumidifying or drying the air or another gaseous fluid through the cooling of this fluid below the dew point temperature, forcing the condensation of the humidity or the water vapor promoted by the passage through a cold coil or cold heat exchanger of evaporation of the refrigeration cycle, being the water condensed, withdrawal or eliminated to a reservoir while the cold and dry air is then forced to pass for a part, conveniently calculated and adjusted, of the coil or heat exchanger of condensation or hot of the same refrigeration cycle, where the air or dry and cold fluid is sufficient and convenient warmed, reusing part of the heat that would be rejected by the refrigeration cycle and producing dry air with low relative humidity.

28. Process of dehumidification or dehydration, in accordance withclaim 27, characterized for dehumidifying or drying through the exchange of humidity between a fluid or dehumidified, dry air, at a temperature above its dew point and closed to the ambient, of low relative humidity and a circuit, chamber, system, substance, spores, mushrooms, fruits, grains, nuts, foods, products, medicaments and compounds formulations, honey, pollen and its derivatives, amongst others, with higher relative humidity, due to the difference of potential of humidity between them and the dry or dehumidified air.