ELECTRONICALLY CONTROLLED HUMIDITY SYSTEM

Abstract: An electronically controlled humidity system is provided comprising a product storage section (1) for housing humidity sensitive products, a control device (2A) for controlling humidity within the product storage section, and a humidity delivery section for delivering humidity into the product storage section, wherein the control device further comprises a humidity sensor (28) and an activator (2a) for said humidity delivery section. Also provided is a module for controlling humidity in a substantially enclosed chamber comprising a control device including a humidity sensor. The module also includes an air inflow device (10), a moisture absorbent material (5) with fluid stored therein, and an air outflow device (11).

Description: ELECTRONICALLY CONTROLLED HUMIDITY SYSTEM TECHNICAL FIELD The present invention relates generally to humidity control systems and, more particularly, to a system for electronically providing precise control of humidity in a substantially enclosed humidity-sensitive environment. BACKGROUND ART Many commercial goods are stored or manufactured in environments where it would be beneficial to control the effects of surrounding humidity with greater precision. For example, manufacturers, retailers and consumers of non-durable products such as cigars, baked goods, floral products, pharmaceuticals, electronics and the like will appreciate that imprecise control of humidity in a product chamber can lead to poor manufacture and storage characteristics, unnecessary spoilage, infestation by insects and molds and so on. Accordingly, it has become desirable to achieve a system wherein humidity is better controlled and the above-described deleterious effects of poor humidity control are avoided. By way of example, those of skill in the tobacco arts have found the negative effects of excessive or inadequate humidification on tobacco products can be reduced by storing goods in a controlled humidity chamber such as a tobacco humidor. A typical tobacco humidor is an enclosed storage box, frequently made of and lined with untreated Spanish cedar or another wood or moisture absorbent material; an absorbent wick or sponge for retaining and imparting moisture into the chamber; and a "dial-type" hygrometer for measuring the storage chamber's relative humidity content. When a user opens the chamber, reads the hygrometer and finds the relative humidity measures lower than desired, more water can be added to the wick or sponge and allowed to evaporate, thus increasing the relative humidity within the chamber. This configuration suffers from the drawback that the chamber must be opened to the external environment to check the hygrometer measurements or withdraw a tobacco product, thus releasing humidity from the chamber and retarding the humidification process. Also, humidors employing nonelectronic dial- type hygrometers typically have much larger margins of measuring error than electronically sensing hygrometers. Another problem associated with the above-described configuration is the varying effects of humidity on the retained moisture content of goods housed in a constant relative humidity but subject to different temperatures. An ideal compound's retained moisture content is a linear function of only the surrounding relative humidity, described by the equation Q = k(RH), where Q is the retained moisture content, RH is the relative humidity content and k is a constant coefficient dependent upon the physical characteristics of the compound. Organic products, however, are not ideal compounds, but complex systems of elements and structures which may deviate significantly from the above-described relative humidity dependent linear relationship. Accordingly, it is found that approaches which ignore the impact of temperature on relative humidification effects are inferior for maintaining precise control of environments housing humidity-sensitive products. Slightly more sophisticated humidors have employed a fan or blower for continuously blowing air through a moistened wick located within the chamber, the wick typically drawing moisture by capillary action from a fluid reservoir, thereby adding both liquid and vaporous moisture to the environment directly. Still others include a heating element positioned beneath a stored container of water, so that water vapor can be added to the humidor's environment as a result of evaporative processes induced by heating. However, there are a number of technical problems associated with these approaches also. For example, humidors equipped with moistened wicks through which air is propelled with a fan or blower tend to release uncontrolled amounts of potentially contaminated liquid moisture, rather than controlled amounts of vapor, into the chamber and onto the goods stored therein. Tobacco goods which become wettened by fluid, rather than bathed in moist vapor, can provide localized breeding grounds for molds, fungi, tobacco beetles and the like which are indigenous to tobacco products. This is also true for systems relying exclusively on heating elements to facilitate water vapor delivery. As the heating element grows warmer, relative humidity is increased in the chamber by the process of evaporation of water into gas; however, the temperature within the chamber also necessarily increases, again providing a conducive environment for the promulgation of molds, fungi, beetles and the like. Finally, the above-described configurations also fail to address problems associated with rehumidifying products which have previously dried out as a result of storage in an environment suffering from inadequate humidity control. For example, rapid rehumidification of a cigar by immersion in an atmosphere which would otherwise be ideal if the cigar had not been allowed to dry out may instead cause the wrapper to swell, peel or crack as its moisture content increases disproportionately to the moisture content diffused back into the body of the cigar. Such damage will render the cigar unsuitable for both smoking and future restoration attempts. Those who are skilled in the appropriate arts will recognize precise and controlled humidity restoration capabilities may also allow revival of a number of other organic products as well, such as papers, scrolls and artifacts or the like, by slowing increasing environmental humidity to a predetermined amount in a substantially enclosed chamber over an extended period of time. To overcome the problems discussed above, an electronic humidity control system is provided wherein precision control of the effects of humidity on goods stored in a substantially enclosed chamber is realized, and problems with poor humidity such as poor manufacture and storage characteristics, unnecessary spoilage and infestation by beetles and molds and the like are avoided. BRIEF DESCRIPTION OF THE DRAWINGS Referring now to the drawing sheets attached hereto, Figure 1 is a side view of a humidity control system within the scope of the present invention; and Figure 2 is a side view of a second humidity control system within the scope of the present invention. MODES FOR CARRYING OUT THE INVENTION Referring now to accompanying Figure 1, a module suitable for retrofitting an existing humidity chamber lacking the advantages of the present invention is depicted comprising a product storage section 1, a control device 2a, and a sensing device 2b. When air within product storage section 1, in which the module embodying the present invention has been placed, is exposed to sensing device 2b, sensing device 2b will determine relative humidity and/or temperature values for the measured air. When sensing device 2b measures insufficient humidity present in the air to maintain the desired humidification effects within product storage section 1, control device 2a activates air intake device 3a, which draws air from product storage section 1 into humidity delivery section 4 via plenum 3b and air outflow device 3c. Once the air drawn from product storage section 1 has entered humidity delivery section 4, the air is then either forced or drawn over a moisture absorbent material 5, or alternatively, over a container of stored fluid. Moisture absorbent material 5 may be either partially or fully saturated with an absorbed fluid such as water or the like, and may be treated with copper sulphate or another nonvolatile substance to help retard the spread of organic growths and infestations. In certain embodiments, a level detector 7 for detecting the level of the fluid absorbed in moisture absorbent material 5 is employed, and in still further embodiments a heating element 8 is provided for heating either the fluid absorbed in moisture absorbent material 5 or the humidity conditioned air produced thereby before the air is recirculated back into product storage section 1 via air outflow device 9. Those of skill in the appropriate arts will recognize that air intake device 3a and air outflow devices 3 c and 9 may comprise a fan, valve, door or flap or the like for assisting the circulation of air drawn from product storage section 1 through humidity delivery section 4 and back into product storage section 1. Air outflow devices 3c and 9 may also form a substantial seal when in a closed position to prevent the fluid absorbed in absorbent material 5 from spilling or leaking into product storage section 1 should the entire system be rotated or tilted, and to prevent uncontrolled diffusion of vapor into product storage section 1. Also, a permeable membrane 6 may be disposed over moisture absorbent material 5 for further limiting the migration of liquid from moisture absorbent material 5 into other parts of the system. Referring now to Figure 2, another exemplary embodiment of the present invention is depicted comprising a product storage section 1, air circulation section 12, and humidity delivery section 4. Air circulation section 12 further comprises an air intake device 10, an air outflow device 11, and at least one of a humidity sensor 2b, temperature sensor 2c or a timing device (not shown). In certain embodiments, air intake device 10 may comprise a fan, valve, door or holes or the like for drawing air from product storage section 1 into air circulation section 12 for analysis by humidity and temperature sensors 2b and 2c, respectively. Humidity and temperature sensors 2b and 2c, which may be located either on or in communication with control device 2a, determine relative humidity and temperature values for the air drawn from product storage section 1. In still further embodiments, air outflow device 11 comprises a fan, valve, door or holes or the like for substantially sealing off each of the system sections from one another when air outflow device 11 is closed. In yet further embodi- ments, air intake device 10 and/or air outflow device 11 comprise a flap, valve or door or the like which opens in response to pressure induced by air flow through the system, or in response to an electronic signal from control device 2a, and which forms a substantial seal when in a closed position. For applications wherein substantial humidity gradients do not occur, air circulation section 12 and air intake/outake devices 10 and 11, respectively, may be eliminated from the system. Also depicted in Figure 2 is a humidity delivery section 4, comprising an air intake device 3 a, a moisture absorbent material 5, and an air outflow device 9. In another embodiment, humidity delivery section 4 further comprises a heating element 8 and/or a level detector 7 for detecting the level of fluid retained in moisture absorbent material 5. In one embodiment of the invention, air intake device 3 a and/or air outflow device 9 comprise a door, flap or valve or the like which opens in response to pressure induced by air flow through the system, or in response to control device 2a, for substantially sealing off humidity delivery section 4 when air outflow device 9 is closed. In this embodiment, as air drawn from product storage section 1 by air intake device 10 contacts humidity sensor 2b and temperature sensor 2c, humidity and temperature values for the drawn air are determined. When humidity sensor 2b and temperature sensor 2c communicate to control device 2a an insufficient relative humidity percentage present in the air to maintain desired humidification characteristics within product storage section 1 given a particular temperature, air intake device 3 a is activated by control device 2a, thereby drawing air from product storage section 1 into humidity delivery section 4 for humidity and/or temperature conditioning. In certain other embodiments, control device 2a may comprise, either structurally integral therewith or as discrete components, one or more of a temperature sensor, a humidity sensor, a timing device, an air circulation section activator, a humidity delivery section activator, or controllers for opening and closing air intake devices 3 a and 10 or air outflow devices 9 and 11. Humidity sensor 2b may alternatively comprise one or more of a humidity sensitive capacitor or resistor. In still further embodiments, control device 2a may also include an integrated circuit with an algorithm or a look-up chart or the like embedded therein for determining a relative humidity percentage which will provide the desired humidification effects as a function of temperature and/or time. Control device 2a may further control the temperature within humidity chamber 1 by controlling one or more of a heating device 8 or cooling device 13. Control device 2a may also comprise a controller for controlling a drier, refrigeration means, or a pump (not shown), for removing moisture from the environment when the relative humidity percentage is too high. Finally, product storage section 1 may also comprise an outside air intake device 14 or external sensing device 16 responsive to control device 2a for admitting air from outside the humidity controlled system when necessary or desirable to achieve particular humidification effects. Those of skill in the art will understand that control device 2a may be a number of discrete devices for accomplishing any or all of the functions described above, and may also be located, either together, separately or in combination, in product storage section 1, air circulation section 12, humidity delivery section 4 or even outside the system entirely. Those of skill will also appreciate that a heating element 8 or a cooling element 13 may also be disposed in either the product storage section 1, air circulation section 12 or humidity delivery section 4, or eliminated entirely from the configuration. Referring still to Figure 2, humidity delivery section 4 further comprises a moisture absorbent material 5 and a fluid absorbed therein for adding humidity to the air drawn by air intake device 3 a, the humidity being increased as a result of processes induced by air moving over the moisture absorbent material 5. In certain embodiments, copper sulphate or another nonvolatile substance is added to the fluid absorbed within moisture absorbent material 5 for retarding the growth of molds or other undesirable organisms, and, alternatively, the fluid or the moisture absorbent material 5 is also impregnated with a perfume having the odor of certain woods or the like. In a still further embodiment of the invention, the moisture absorbent material 5 comprises a very porous and fluid-retaining material such as florist foam or the like, which permits vapor to be added to the air being circulated through humidity delivery section 4 while minimizing the migration of liquid moisture. In a yet further embodiment, moisture absorbent material 5 is substantially covered by a permeable membrane 6 to better facilitate containment of the fluid absorbed in moisture absorbent material 5. In a still further embodiment, moisture absorbent material 5 is replaced by a container of stored fluid which may also be covered by a permeable membrane if desired. Air outflow device 9 may also comprise one of a flap, valve or door or the like, responsive to either pressure induced by air flow, or as a result of an electron- ic signal from control device 2a. In one embodiment, air outflow device 9 and air intake device 3 a include doors, flaps or valves or the like which substantially provide a seal when closed, so that the fluid stored in moisture absorbent material 5 will not pour out when the system is rotated or tilted, and to isolate generated humidity from the humidity delivery section 4 when desirable. In yet further embodiments, one or more of a heating element 8 or cooling element 13 may be located, either together or separately, in one or more of the product storage section 1, air circulation section 12 or humidity delivery section 4, and be controlled by control device 2a. Referring again to control device 2a, those of skill will appreciate that certain embodiments will comprise at least one of a plurality of control components such as a humidity sensor, a temperature sensor, an air circulation section activator, a humidity delivery section activator, a timing device, an air intake device 3a or 10 activator, an integrated circuit with an algorithm or a look-up chart or the like embedded therein for determining the proper amount of relative humidity necessary to provide the desired humidification effects as a function of temperature or time, a controller or set of controllers for opening or closing air outflow devices 9 or 11, an activator for turning on or off heating element 8 or cooling element 13, or a controller or set of controllers for controlling one or more of a plurality of remote circulation fans 15. As discussed above, the humidity sensor may comprise one or more of a humidity sensitive capacitor or resistor as are well known to those of skill in the appropriate arts, or alternatively, comprise one or more of a combination of the above-described components in the form of a system of individually discrete components located either in product storage section 1, air circulation section 12, humidity delivery section 4, or in a combination thereof. An additional sensing device 16 may also be disposed outside the controlled environment for still more precise humidity control. Finally, in an exemplary embodiment, either the interior or exterior of the substantially enclosed humidity chamber may comprise a moisture absorbent wood, such as Spanish cedar or the like, but may also comprise other materials, such as plastic for example, which are impregnated with an appropriate wood odor. Alternatively, the innermost portion of the chamber may be lined with wood or another material and further impregnated with an appropriate wood odor. Those of skill in the appropriate arts will appreciate that aspects of the present invention as claimed below will admit to many other embodiments than those recited above, and nothing in the instant description should be viewed as a limitation of those further embodiments. Industrial Applicability As discussed above, the presently provided electronically controlled humidity system is applicable to any industrial application wherein goods are stored or manufactured in environments in which it would be beneficial to control the effects of surrounding humidity with greater precision, such as the manufacture or storage of tobacco products, baked goods, floral products, pharmaceuticals, electronic components and the like.

Claims: CLAIMS 1. An electronically controlled humidity system comprising: a product storage section for housing humidity sensitive products; a control device for controlling humidity within said product storage section; and a humidity delivery section for delivering humidity into said product storage section, wherein said control device further comprises a humidity sensor and an activator for said humidity delivery section. 2. The humidity system of claim 1, wherein said control device further comprises a temperature sensor. 3. The humidity system of claim 1, wherein an outermost portion of said product storage section comprises a material which visually resembles wood. 4. The humidity system of claim 1, wherein an outer covering for said product storage section is impregnated with a wood odor. 5. The humidity system of claim 1, wherein an innermost portion of said product storage section comprises a material which visually resembles wood. 6. The humidity system of claim 1, wherein an inner covering for said product storage section is impregnated with a wood odor. 7. The humidity system of claim 1, wherein said humidity sensor further comprises a humidity-sensitive resistor. 8. The humidity system of claim 1, wherein said humidity sensor further comprises a humidity-sensitive capacitor. 9. The humidity system of claim 1, wherein said control device further comprises a controller for controlling at least one remote air circulation device. 10. The humidity system of claim 1, wherein said control device further comprises an integrated circuit in which an algorithm for determining desired relative humidity values as a function of temperature is embedded therein. 11. The humidity system of claim 1, wherein said control device further comprises an integrated circuit in which an algorithm for determining desired relative humidity values as a function of time is embedded therein. 12. The humidity system of claim 1, wherein said control device further compris- es an integrated circuit in which a look-up chart for determining desired relative humidity values as a function of temperature is embedded therein. 13. The humidity system of claim 1, wherein said control device further comprises an integrated circuit in which a look-up chart for determining desired relative humidity values as a function of time is embedded therein. 14. The humidity system of claim 1, wherein said humidity delivery system further comprises a product storage section, an air circulation section and a humidity delivery section. 15. The humidity system of claim 14, wherein said air circulation section further comprises an intake device for removing air from said product storage section, a control device, and an air outflow device for circulating air back into the product storage section. 16. The humidity system of claim 14, wherein said humidity delivery section further comprises an intake device for removing air from the air circulation section; a moisture absorbent material; and an air outflow device for returning air into the circulating section. 17. A control device for electronically controlled humidity systems comprising a humidity sensor, a temperature sensor, an integrated circuit with an algorithm for determining a desired relative humidity content as a function of temperature embedded therein, and an activator for said humidity delivery section. 18. The control device of claim 17, wherein a plurality of control device compo- nents are not formed structurally integral with one another. 19. The control device of claim 17, wherein said control device further comprises an activator for a heating element. 20. The control device of claim 17, wherein said control device further comprises an activator for a cooling element. 21. The control device of claim 17, wherein said control device further comprises at least one controller for controlling the operation of at least one air outflow device. 22. A module for controlling humidity in a substantially enclosed chamber comprising a control device including a humidity sensor; an air inflow device; a moisture absorbent material; and an air outflow device. 23. The module of claim 22, wherein either said moisture absorbent material or a fluid contained therein is impregnated with a perfume including the odor of a moisture absorbent wood. 24. The module of claim 22, wherein said control device comprises a humidity sensor, a temperature sensor, an integrated circuit with an algorithm for determining a desired relative humidity as a function of temperature embedded therein, and a humidity delivery system activator. 25. The module of claim 22, wherein said humidity sensor comprises a humidity sensitive resistor. 26. The module of claim 22, wherein said humidity sensor comprises a humidity sensitive capacitor. 27. The module of claim 22, wherein said air outflow device comprises at least one flap responsive to pressure induced by air flow. 28. The module of claim 22, wherein said air outflow device comprises at least one door which forms a substantial seal when in a closed position. 29. The module of claim 22, wherein said air inflow device comprises at least one flap responsive to pressure induced by air flow. 30. The module of claim 22, wherein said air inflow device comprises at least one door which forms a substantial seal when in a closed position. 31. The module of claim 22, wherein either said moisture absorbent material or a fluid absorbed therein further comprises a copper sulphate solution. 32. The module of claim 22, wherein either said moisture absorbent material or a fluid absorbed therein further comprises a nonvolatile substance for retarding the growth of organic growths. 33. The module of claim 22, wherein said moisture absorbent material is substantially covered by a permeable membrane.

Inventors: CRUM WAYNE M, INGBER HOWARD S, CRUM, WAYNE, M., INGBER, HOWARD, S.
Applicants: CRUM WAYNE M, INGBER HOWARD S, CRUM, WAYNE, M., INGBER, HOWARD, S.
Application year: 1997
Main classification: B01F3
IPC codes: G05D22