Abstract:
A permeable saturation body absorbs a liquid chemical for evaporative dispersion. External air is forced through the saturation body to vaporize and carrying the liquid chemical into a prescribed area. The liquid container and permeable body are mounted on a permeable support structure. Excess liquid dripping from the permeable saturation body is recaptured and redistributed by another permeable saturation body located below the first permeable saturation body. The device can be used in greenhouses to disperse insecticide into the air or along the ground. The device is also adapted to disperse deodorant or a bactericide for use in hospitals or restaurants, for example. One embodiment of the invention provides for reversible air flow so that a user can choose between dispensing the liquid chemical in a low position, or in a high position.

Description:
This is a continuation-in-part of pending application Ser. No. 08/561,459 filed Nov. 21, 1995, now U.S. Pat. No. 5,829,188. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a chemical diffusion device for use in facilities such as greenhouses, hospitals and restaurants. 
     Greenhouses are often used for production of such staples as strawberries, melons, cucumbers and tomatoes. Oil is often used to heat the greenhouses, resulting in a warm, moist environment. This environment, combined with good lighting, provides an ideal setting for the proliferation of various noxious insects. Generally, insect population growth has been checked by manual application of liquids such as agricultural pesticides. Usually, these pesticides are sprayed on the particular plants by a laborer. 
     Hospitals, restaurants and food processing plants tend to have problems with insects as well. However, these types of facilities also suffer from problems related to bacteria and noxious odors. These problems also can be eliminated by application of a liquid pesticide, bactericide or deodorant. 
     Application of the above liquids by manual spraying can be an irritating and annoying inconvenience. In addition, inhalation of fumes from these liquids can pose a health hazard. It is also a difficult task to place the liquids in an appropriate setting to accomplish their designed function. 
     OBJECT AND SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a chemical diffusion device which overcomes the drawbacks of the prior art. 
     It is a further object of the invention to provide a chemical diffusion device for effectively diffusing chemicals such as insect extermination liquids, bactericides and deodorants. 
     It is a further object of the invention to provide a chemical diffusion device which can be operated to diffuse chemicals along the ground or in the air. 
     Briefly stated, the present invention provides a permeable saturation body that absorbs a liquid chemical for evaporative dispersion. External air is forced through the saturation body to vaporize and carrying the liquid chemical into a prescribed area. The liquid container and permeable body are mounted on a permeable support structure. Excess liquid dripping from the permeable saturation body is recaptured and redistributed by another permeable saturation body located below the first permeable saturation body. The device can be used in greenhouses to disperse insecticide into the air or along the ground. The device is also adapted to disperse deodorant or a bactericide for use in hospitals or restaurants, for example. One embodiment of the invention provides for reversible air flow so that a user can choose between dispensing the liquid chemical in a low position, or in a high position. 
     According to an embodiment of the invention, there is provided a chemical diffusion device comprising: a case having a first opening in a first end and a second opening in a second end, at least one container in the case for containing a liquid chemical, the container having an open upper end, at least one support body supporting the container, the support body permitting the passage of air therethrough, a material on a surface of the support body, the material having an end disposed to contact the liquid chemical in the container, the material being of a type capable of absorbing the liquid chemical through capillary action, the material being gas-permeable, an inner surface of the material being exposed to the first opening, an outer surface of the material being exposed to the second opening, and means for moving air into one of the first opening and the second opening, and out the other thereof, whereby the air passes through the material, and evaporates the liquid chemical. 
     Advantageously, the at least one container includes a first container, the at least one container further includes a second container, the second container being disposed below a lower end of the material to collect an excess of the liquid chemical from the material, a second support body below the second container, a second support body supporting a second material, and the second material receiving an overflow of the liquid chemical from the second container, whereby evaporation of the liquid chemical is increased. 
     According to another embodiment of the invention, there is provided a chemical diffusion device comprising: a case having a first opening in a first end and a second opening in a second end, a plurality of containers including a first, second and third container in the case for containing a liquid chemical, the containers having an open upper end, a plurality of gas-permeable support bodies including a first support body above a second support body, the support bodies supporting a gas-permeable material on a surface of the support bodies, the material being of a type capable of absorbing the liquid chemical and having an end disposed to contact the liquid chemical in the first container, the material having a lower end disposed to drip into the second container to collect an excess of the liquid chemical from the material, the material on a surface of the second support body receiving an overflow of the liquid chemical from the second container, an outer surface of the material being exposed to the first opening, an inner surface of the material being exposed to the second opening, and means for moving air into one of the first opening and the second opening, and out the other thereof, whereby the air passes through the material, and evaporates the liquid chemical. 
     The present invention includes a container that stores a liquid chemical. The liquid chemical feeds into a permeable saturation body from the container via capillary action. The permeable saturation body is mounted on a permeable support body. A fan vaporizes the liquid chemical by passing air over and through the permeable saturation body. The device includes a motor for turning the fan. 
     In the above configuration, the permeable saturation body is saturated by the liquid chemical fed from the storage container via capillary action. The fan is rotated by the motor so that air passes through permeable saturation body. The motion of the air passing the permeable saturation body causes the liquid saturated therein to evaporate. The liquid chemical, now an evaporated and vaporized gas, diffuses into the surrounding prescribed area. 
     The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a chemical diffusion device according to an embodiment of the invention. 
     FIG. 2 is a view of the device of FIG. 1 wherein a section of the exterior is cut away to reveal interior parts. 
     FIG. 3 is a partially cut away perspective view of the vaporization unit of the chemical diffusion device. 
     FIG. 4 is a cross-section view of the vaporization unit in FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, the chemical diffusion device, shown generally at  20  according to the present invention, is used to exterminate various kinds of insects in facilities such as restaurants or greenhouses. Device  20  has a case  1  and a cap  2  removably mounted on an upper portion of case  1 . An intake hole  3  is formed in cap  2  to allow the insect extermination chemical to be placed within device  20 . A middle cylinder  5  is mounted above a cylindrical base  4 . Case  1  is removably mounted above middle cylinder  5 . 
     A stopping piece  19  detachably engages case  1  and middle cylinder  5 . A power switch  6  is disposed on an outer surface of cylindrical base  4 . A hood  7  is disposed on the outer surface of middle cylinder  5 . A ventilation opening  8  is formed in a surface of hood  7 . A slit-shaped opening  9  is formed between case  1  and cap  2 . 
     Referring to FIGS. 2,  3  and  4 , a vaporizing unit  10 , located within case  1 , vaporizes the insect exterminating liquid chemical  12 . Liquid chemical  12  is stored in a circular plate-shaped liquid storage container  11 . Liquid storage container  11  is mounted above a support  13 . Support  13  is permeable since it is constructed from a cylindrically shaped lattice frame. A gauze  14  is mounted on a surface of support  13  to act as a permeable saturation body. Support  13  provides a structure for supporting both liquid storage container  11  and gauze  14 . Gauze  14  includes a thick portion  14   a , which can contain large amounts of chemical  12 , and a thin tongue portion  14   b  on an upper end. Tongue portion  14   b  curls over the upper edge of liquid container  11  to be immersed in chemical  12 . A thin portion  14   c  is formed on a lower end of gauze  14 . Support  13  is disposed above a ring-shaped container  15 . A lower end of thin portion  14   c  is positioned within ring-shaped container  15 . Vaporizing unit  10  can be removed from middle cylinder  5  along with case  1 . After removal, vaporizing unit  10  is easily replaced in case  1 . Easy replacement of vaporizing unit  10  makes handling and maintenance of device  20  simple and more efficient. 
     Tongue portion  14   b  feeds liquid chemical  12  from liquid container  11  to gauze  14  by capillary action. Liquid chemical  12  seeps downward into thick portion  14   a  and then into thin portion  14   c .  12 . A substantial part of liquid chemical  12  is evaporated from thick portion  14   a  and thin portion  14   c . Ring-shaped container  15  accumulates remaining unevaporated excess liquid chemical  12  that drips down from the lower end of thin portion  14   c . The feeding and seeping processes keep gauze  14  constantly saturated with liquid chemical. When most or all of liquid chemical  12  has been removed in this way, container  11  is refilled through intake hole  3 . 
     Referring to FIGS. 2 and 4, a sub-vaporizing unit  10 ′ is located within middle cylinder  5 . Sub-vaporizing unit  10 ′ has roughly the same configuration as above described vaporizing unit  10 . A support  13 ′ is a cylindrically shaped lattice frame on which a gauze  14 ′ is mounted and supported. Gauze  14 ′ is supported by a top surface and other outer surfaces of support  13 ′ . Support  13 ′ and the lower end of gauze  14 ′ are mounted on a ring-shaped container  15 ′. Liquid chemical  12  that overflows from ring-shaped container  15  in vaporizing unit  10  flows down to a top surface of gauze  14 ′ of sub-vaporizing unit  10 ′, as indicted by arrows A in FIG.  4 . Gauze  14 ′ becomes saturated by the overflow of chemical  12 . Excess liquid chemical  12  from saturated gauze  14 ′ drips down and is stored in ring-shaped container  15 ′. Sub-vaporizing unit  10 ′ thus recovers and evaporates excess liquid chemical  12  that has dripped off of ring-shaped container  15 . 
     Referring to FIGS. 1 and 2, a sirocco fan  16 , disposed below sub-vaporizing unit  10 ′, is driven by a motor  17  disposed within cylindrical base  4 . A power cord  18  connects motor  17  to a power source. When power switch  6  is moved to the “ON” position, motor  17  rotates fan  16  to draw air from outside cylindrical into case  1  through slit-shaped opening  9 . It should be readily recognized that motor  17  and fan  16  can be replaced by other means for moving air, such as a compressed or pressurized air line feed. 
     Handling and operation of device  20  of the present invention is described as follows. Chemical diffusion device  20  of the present invention is installed in an appropriate position within a greenhouse. Power switch  6  is moved to the “ON” position, causing motor  17  to rotate fan  16 . Fan  16  draws air from outside case  1  into device  20  through slit-shaped opening  9 . The drawn-in air passes through gauze  14 , as indicated by arrows N in FIG.  4 . The drawn-in air then exits device  20  through ventilation opening  8 . The passing air evaporates liquid chemical  12  as it passes through and around saturated gauze  14 . The vaporized gas is blown out with the air to exterminate insects within the greenhouse, or for other purposes. FIGS. 1 and 2 show the flow of air with dashed arrows. The air drawn into case  1  through slit-shaped opening  9  tends to pass through thick portion  14   a  of gauze  14 . When saturated, thick portion  14   a  retains large amounts of chemical  12 . The large amounts of liquid chemical  12  retained prevent thick portion  14   a  from drying out. 
     Produce grown near the ground, for example strawberries, benefits from gas produced by device  20  according to the present invention when the gas is blown toward the ground. Likewise, insects such as cockroaches that may be found near the ground or the floor in restaurants and the like are exterminated by a ground-directed stream of gas from device  20 . 
     In applications such as those described above, it is desirable to keep the gas at a low temperature and a high specific gravity. Air passing through gauzes  14 ,  14 ′ of present device  20  vaporizes chemical  12 . The vaporization of liquid chemical  12  saturated within gauzes  14 ,  14 ′ produces evaporative cooling which results in a temperature drop. Active methods for lowering the gas temperature can also be used. Active methods include cooling insect exterminating liquid chemical  12  in a refrigerator before insertion into liquid container  11 , and putting chunks of ice into liquid container  11 . Using these means to actively lower the temperature of the gas is desirable because the increase in specific gravity allows the gas to diffuse along the ground or floor. The present invention therefore does not necessarily require active cooling of the liquid that is converted to a gas. 
     Produce grown upright or in the air, melons or tomatoes for example, presents another application for device  20  according to the present invention. In this situation it is desirable to have the gas used to exterminate pests blown upward into the air. Device  20  according to the present invention accomplishes this goal by causing motor  17  to rotate in an opposite direction. When motor  17  rotates in an opposite direction, fan  16  draws air into device  20  through lower ventilation opening  8 . The drawn-in air passes outward through saturated gauzes  14 ′ and  14  and then through upper slit-shaped opening  9 . The gas expelled through upper slit-shaped opening  9  is dispersed into the surrounding air. The above is an effective method for exterminating insects that attach themselves to produce such as melons, tomatoes and the like above the ground. 
     In order to provide for moving air selectively upward and downward, as described above, power switch  6  has two “ON” positions, separated by an “OFF” position. One of the positions controls driving of fan  16  in one direction, and the other position controls driving of the fan  16  in the opposite direction. 
     Chemical diffusion device  20  according to the present invention can also be used in other applications. For example, device  20  can be installed in food processing plants or hospitals to exterminate insects that crawl on the ground such as cockroaches. Device  20  can be made to have a sanitary function by replacing the exterminating liquid with a bactericide such as formalin. Device  20  in such a configuration destroys unwanted bacteria in a hospital or other such facility. Alternatively, liquid chemical  12  in container  11  can be a deodorant. Device  20  in this configuration acts as a deodorizer. 
     As illustrated by these brief examples, the chemical diffusion device  20  according to the present invention has a wide variety of applications. Moreover, the present invention is not restricted to the above described embodiments. For example, a small hole at the bottom of liquid storage container  11  would allow the insect exterminating liquid chemical  12  to drip down and saturate gauze  14 ′. 
     The above described device  20  according to the present invention efficiently exterminates insects that live on the ground in greenhouses and other similar structures. Device  20  also exterminates insects or pests that are present on produce grown on the ground such as strawberries. Device  20  also can be configured to exterminate insects on produce grown suspended in air, such as melons and tomatoes. Device  20  according to the invention also exterminates cockroaches and other pests on the floors of facilities such as restaurants and hospitals. The present invention can also be used as a bactericide device  20  or a deodorizer in a hospital or other facilities where bacteria and odor are undesirable. 
     Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.