Beehive treatment systems

A beehive treatment system utilizing an oxalic acid vaporization process is used to treat honey bee colonies against the adverse effects of infestation by the Varroa Mite pest. The beehive treatment system includes units having heating chambers configured to vaporize crystalline oxalic acid. Implementations include an air-flow pre heat circuit to prevent crystallization of oxalic acid when treating a beehive.

BACKGROUND

The present disclosure relates to beehive treatment systems and more particularly to a unique oxalic acid vaporization technique to treat honey bee colonies against the adverse effects of infestation by the Varroa Mite pest. The Varroa Mite has been identified as the most harmful pest impacting Western honey bees,Apis mellifera Linnaeus(Hymenoptera: Apidae). The Varroa destructor species is responsible for the vast majority of the damage attributed to mites. Oxalic acid vaporization has been proven to combat mite reproduction in the honey bee colony at 99.9 percent effectiveness with no evidence of the mite developing treatment resistance over the last 30 years.

It is generally accepted that treatment of beehives using oxalic acid vaporization is safe and effective when properly implemented; however, proper treatment of hives using vaporization is difficult to achieve using current methodologies. An optimized treatment requires both a controlled sublimation of oxalic acid crystals and thorough distribution of the resulting vaporized oxalic acid within the hive enclosure. Furthermore, oxalic acid vapor is potentially hazardous to beekeepers if improperly handled. New treatment systems capable of administering oxalic acid in a safe and controlled manner would be of benefit to many.

DETAILED DESCRIPTION

The present disclosure relates to beehive treatment systems and more particularly to an oxalic acid vaporization technique to treat honey bee colonies against the adverse effects of infestation by the Varroa Mite pest. According to the various implementations of a beehive treatment device of the present disclosure, the vaporization and dispensing of vaporized oxalic acid (C2H2O4) is made more effective by implementing a rapid oxalic acid vaporization process that minimizes waste of the compound. As will be shown and described herein, only oxalic acid vapor is dispensed by the device since vapor from the heated oxalic acid is drawn or pulled from a heated chamber while the crystalized oxalic acid within the heated chamber until completely vaporized. Additionally, the various implementations of a beehive treatment device of the present disclosure comprises features structured and arranged to reduce unintentional recrystallization of oxalic acid after being vaporized. Recrystallization of oxalic acid can clog the device and lower user's effectiveness of treating hives. As will be discussed herein, the position of an air flow tube via outlet tube tie-in that avoids a barrel-in-barrel alignment and forward to an outlet tube prevents clogging. Also, an air flow pre-heat circuit described herein heats air in the air flow circuit so that air used with the device does not contribute to oxalic acid recrystallization when the air makes contact with vaporized oxalic acid.

In a general sense, a beehive treatment device of the present disclosure comprises a heating chamber or vessel, a heating element to heat up the heating chamber, a heating chamber inlet to introduce oxalic acid (that will become vaporized when the heating element heats the heating chamber), and an outlet connected to the heating chamber for vaporized oxalic acid to escape. Implementations of the present disclosure comprise an air flow source, which may be a source of compressed air, a fan, an air blower, etc. The air flow source comprises some type of air flow source actuator (an on/off switch, an open/closed valve) and air flow source regulator of the air flow rate (a valve, a fan-speed dial, etc.). The air flow source is connected to an air flow tube. The air flow tube is connected to the outlet via an outlet tube tie-in. In one implementation of the present disclosure, the outlet is an outlet tube and the outlet tube tie-in is connected to an exterior wall of the outlet tube and forward of an opening where the outlet is connected with the heating chamber (seeFIG. 6). The outlet tube may be positioned in anywhere so long as it is in communication with the heating chamber. The outlet tube tie-in and outlet tube may alternatively have a barrel-in-barrel arrangement (seeFIG. 7). The barrel-in-barrel arrangement is less preferred due to possible recrystallization of oxalic acid in between the outlet tube and outlet tube tie-in (which would cause clogging and would be difficult to clean). The outlet tube may be cleaned by forcing air at a very high rate through the outlet tube. To further prevent crystallization, an air flow tube pre-heat circuit is utilized to heat air from the air flow source. In doing so, when heated air contacts the vaporized oxalic acid, crystallization will be minimized if not eliminated. Without the air flow pre-heat circuit, a temperature difference when non-heated air contacts the vaporized oxalic acid may lead to unintended crystallization of oxalic acid. Various implementations and other features of the beehive treatment devices of the present disclosure will be described below.

Referring now more specifically to the drawings, there is shown inFIG. 1throughFIG. 10various implementations of a beehive treatment system100.FIG. 1shows a perspective view illustrating beehive treatment device102during an “in-use” condition200.FIG. 2shows a perspective view illustrating beehive treatment device102ofFIG. 1.FIG. 3shows a top view of beehive treatment device102ofFIG. 1.FIG. 4shows the sectional view4-4ofFIG. 3.

With reference toFIG. 1throughFIG. 4, the hand-transportable apparatus forming the beehive treatment device102includes an arrangement of interoperating subcomponents. These subcomponents comprise an internal heating chamber104situated within a heating chamber enclosure106, a heating element108that heats the internal heating chamber104, and an actuator110coupled to the heating element108to initiate heating of the heating chamber104. The heating chamber104is used to heat crystalline oxalic acid105to a temperature sufficient to produce vaporized oxalic acid107by sublimation.

According to an implementation of the present disclosure, heating chamber104may include inner pot114having bottom116and surrounding sidewall118, as shown. Pot114may be formed from metal or other heat-resistant materials. Exterior wall120of heating chamber enclosure106surrounds pot114such that the pot114is situated within exterior wall120, as shown. Heating element108is positioned between exterior wall120of heating chamber enclosure106and sidewall118of pot114. Heating element108is configured to transfer heat to heating chamber104at a controlled temperature sufficient to vaporize crystalline oxalic acid105without producing chemical degradation of the compound. Both heating chamber enclosure106and outer housing124of actuator110may be mounted to a rigid base member126.

Inlet tube128(a heating chamber inlet) is connected to internal heating chamber104and provides a direct opening into the heating chamber104for the introduction of crystalline oxalic acid105(seeFIG. 4). Inlet tube128is shown as an elongated tube. Inlet tube128may be removable. A pressure differential developed within heating chamber104allows inlet tube128to remain open during operation. This permits the introduction of crystalline oxalic acid105into inner pot114at any time during or prior to operation. The positioning of inlet tube128directly above inner pot114assists in producing an even distribution of crystalline oxalic acid105within the heating chamber104thus promoting complete vaporization of the crystalized product.

Outlet tube130is shown connected to heating chamber104through heating chamber enclosure106, as shown. Outlet tube130may be removable. The connection defines an opening132connecting the heating chamber104with outlet tube130, as shown. Outlet tube130provides a discharge pathway for vaporized oxalic acid107generated in heating chamber104. InFIG. 10, outlet tube130is shown in a different position on heating chamber enclosure106. As shown herein, outlet tube130may be placed in numerous positions and achieve the same effect.

The beehive treatment device102includes an air flow tube134adapted to couple to an air flow source. The present discussion identifies pressurized air as the air flow source which is further identified as compressed air136(seeFIG. 1). As will be discussed below, other air flow sources may suffice. Air flow from the air flow source through beehive treatment device102is shown in various figures as air flow1361. The distal end of the air flow tube134may be equipped with an industry-standard air-hose coupler fitting138, such as the quick-connect-type fitting depicted inFIG. 2-FIG. 4. This allows the air flow tube134and the source of compressed air136to be coupled using a flexible airline140, as shown inFIG. 1. It is noted that implementations of the present system may include the source of compressed air136. For portability and convenience, the source of compressed air136may be a compact compressed-air tank142having an integral control valve144, as shown inFIG. 1. Alternately, the source of compressed air136may be substituted with a fan or blower.

Air flow tube134comprises an outlet tube tie-in146connected to an exterior wall148of the outlet tube130, as shown. According to an implementation of the present disclosure, outlet tube tie-in146is located at a point forward of opening132connecting heating chamber104with outlet tube130. Air flow tube134may also include an air flow regulator depicted as valve150located between outlet tube tie-in146and the source of compressed air136. Valve150regulates the rate of air flowing into the air flow tube134. Valve150may be secured to outer housing124of actuator110or other rigid structure of the assembly to prevent damaging the connected components (such as due to repeated use of the device creating vibrations that induce wear and tear on the connected components).

A reduced-pressure suction force is produced within the outlet tube130near opening132by a reduced-pressure generator assembly152operating on Bernoulli's principle of conservation of energy. More specifically, reduced-pressure generator assembly152utilizes a stream of compressed air within outlet tube130to create a pressure drop near opening132, thereby drawing the vaporized oxalic acid107out of internal heating chamber104. Vaporized oxalic acid107drawn from internal heating chamber104is mixed with the compressed air and discharged at the distal end of the outlet tube130. As outlet tube130and internal heating chamber104are in fluid communication, a reduced pressure is generated within heating chamber104as vaporized oxalic acid107is drawn into outlet tube130. This produces a pressure-biased backflow of air from the higher-pressure inlet tube128(the tube where the crystalline oxalic acid105is initially inserted) toward the interior of heating chamber104. This pressure bias prevents vapor from exiting inlet tube128into the operator's breathing space (thereby reducing user exposure to oxalic acid vapor). Upon reading this specification, it should be appreciated that, under appropriate circumstances, other pressure modulation assemblies such as, for example, the use of air compressors, a fan positioned at the outlet tube or at an outlet tube tie-in (past the opening of the inlet tube tie-in), one-way gas valves, etc., may suffice.

The distal end of outlet tube130transitions into nozzle154facilitating insertion into beehives. For example, nozzle154is shown inserted into base opening432of beehive109to administer vapor, as best shown inFIG. 1. Nozzle154has a longitudinal axis156that may be oriented in the same orientation as longitudinal axis158of the outlet tube130. Nozzle154may be tapered along its longitudinal axis156, as shown. Outlet tube130and nozzle154each comprise a coaxial barrel160having smooth inner bores162to assist in cleaning the barrels160of any oxalic acid that may re-crystallize during passage through the inner bores162.

Heating chamber enclosure106includes a removable top164to enable periodic cleaning and inspection of inner heating chamber104and related internal components. As shown in the device ofFIG. 1, the device's top164has connections for both inlet tube128and outlet tube130. Top164forms the upper boundary of heating chamber104and is secured to heating chamber104with mechanical fasteners. Suitable mechanical fasteners166may include screws, bolts, clamps, or other fastening devices. Top164is shown fastened to the upper wall of heating chamber104with screws (mechanical fasteners166) and comprises gasket seal170preventing vapor from escaping the chamber once screws (or other securing device) are tightened.

Gasket seal170may be constructed of a heat-resistant material to prevent melting or deformation during chamber calefaction. Gasket seal170also assists to maintain the inner chamber pressure needed to direct vaporized oxalic acid107into outlet tube130under the lower pressure condition induced during the flow of air1361from the source of compressed air136through this tube. The orifices of inlet tube128and outlet tube130may be affixed permanently by brazing or thermal welding.

Heating chamber temperature readout device172may be included. In an implementation of the present disclosure, heating chamber temperature readout device172is show mounted to top164, as shown. Heating chamber temperature readout device172may be a combined temperature gauge and probe configured to measure and display the temperature within pot114during use. Upon reading this specification, it should be appreciated that, under appropriate circumstances, other thermal control and monitoring arrangements such as, for example, a thermally-operated cutoff switch operably coupled to the heating element, mechanical timers, programmable timers, etc., may suffice.

Top164may be detachable and, when so, extends the longevity of the device by enabling one to remove solid residue deposited during vaporization process. Outlet tube130may also be detached from its connection port for simplified transportation and cleaning. The ease of maintenance afforded by the features of the device facilitate optimal performance and longevity of the apparatus.

The above-described beehive treatment device102is configured to heat crystalline oxalic acid105inserted into the heating chamber104via inlet tube128and such air flow tube134to outlet tube tie-in146configured to prevent the flow of vaporized oxalic acid107out of the inlet tube128and to direct the vaporized oxalic acid107out of the outlet tube130when air is flowing through the air flow tube134so that vapor is pulled out of the heating chamber104under negative pressure to deliver vaporized oxalic acid107into the beehive109.

FIG. 5shows the sectional view5-5ofFIG. 4. Visible inFIG. 5is inner heating chamber including pot114, exterior wall120of heating chamber enclosure106, and heating element108. Heating element108is positioned between exterior wall120of heating chamber enclosure106and exterior sidewall118of pot114. To improve heat transfer, heating element108may be placed in direct contact with exterior sidewall118and may be looped around pot114to maximize the contact area. Implementations of beehive treatment device102may further include an insulating material surrounding inner pot114. It is important to note that heating element108does not directly contact the crystalline oxalic acid105or vaporized oxalic acid107to prevent superheating and chemical degradation of the compound. This arrangement also facilitates both the cleaning and maintenance of the device.

Heating element108of beehive treatment device102may be electrically operated employing resistive heating. Such electrical-resistance-type heating elements may be of a well-known design utilizing, for example, a nichrome wire embedded in a ceramic material. Each end of heating element108may be provided with electrical contact174and leads176that connect contacts174to electrical power source178(seeFIG. 1). At least one of the leads is wired in series with a user-controllable variable thermostat180(a temperature adjustment device) allowing one to modulate the temperature within pot114. Variable thermostat180may be of an adjustable bimetallic type, or similar temperature adjustment element that permits a user to adjust the temperature as desired. It is noted that auto-regulation of the temperature of the inner heating chamber104is also possible. For example, under appropriate circumstances, pre-set thermostats calibrated with a specific set-point may be suitable. Variable thermostat180may include control knob182(seeFIG. 1) mounted to outer housing124of actuator110in a user accessible position, as shown inFIG. 3. It is noted that certain features of the disclosed embodiments may be implemented using commercially available components. For example components adaptable for use in the present embodiments may include heating elements, pots, variable thermostats, etc. used in electric melting furnaces distributed by the Lee Precision Company of Hartford, Wis.

Electrical power source178may be supplied as alternating current (AC) or direct current (DC). Electrical power source178may be a DC source provided by a portable battery pack184(seeFIG. 1), or similar electrochemical storage device. Alternately, electrical power source178may be supplied from an AC source, such as 120-volt or 220-volt mains power. Heating element108may have a thermal output of about 500 watts at 120 volts AC. Upon reading this specification, it should be appreciated that, under appropriate circumstances, other heating arrangements such as, for example, vapor-isolated fuel burners, heating elements positioned along the outlet tube to reduce re-crystallization during passage, etc., may be sufficient.

FIG. 6is a diagrammatic sectional view through outlet tube130containing reduced-pressure generator assembly152. In use, valve150is opened (seeFIG. 3) allowing a stream of compressed air to pass through the outlet tube tie-in146and discharge into the outlet tube130at a point forward of opening132. The rapid flow rate of the compressed air produces a pressure drop across opening132by the Bernoulli principle in which a region of fast flowing fluid exerts lower pressure on its surroundings than a region of slow flowing fluid. This reduced-pressure condition draws vaporized oxalic acid107from heating chamber104. The resulting air-vapor mixture flows through the outlet tube130and is discharged at the nozzle154.

Valve150can supply air at a flow rate sufficient for precluding vapor backflow into inlet tube128. The suction of vapor from heating chamber104through outlet tube130under negative pressure conditions assures continuous and steady dispersion of vapor from the device. This method of dispensing oxalic acid vapor is extremely effective due to rapid vaporization and discharge of gaseous oxalic acid only, while leaving the crystalized form behind in the inner chamber of heating chamber104.

FIG. 7is a diagrammatic sectional view through another outlet tube130containing an alternate reduced-pressure generator assembly152. In alternate outlet tube130, a stream of compressed air passes through air flow tube134and is directed through outlet tube130by transfer tube186(a portion of air flow tube134) oriented coaxially with longitudinal axis158. The stream of compressed air is discharged from transfer tube186at a point forward of opening132near nozzle154. The rapid flow of compressed air exiting the transfer tube186produces a pressure drop within inner bore162of alternate outlet tube130, thereby drawing vaporized oxalic acid107from heating chamber104. It should be noted that any performance advantages provided by the tube-in-tube arrangement ofFIG. 7may be offset by the increased difficulty in cleaning the interior of the tube should vapor cooling and deposition of the oxalic acid on the interior surfaces of the tube occur.

FIG. 8shows a side view illustrating beehive treatment device102including strap attachment points188and shoulder strap190. The device may be modified to be wearable using a harness or shoulder strap190to facilitate transport of the device as various beehives in a region are treated. Beehive treatment device102may further include at least one handle192to assist gripping the device during transport and use. The handle may be mounted to outer housing124of actuator110, as shown. Implementations of the beehive treatment device102may have two separate handles192, as shown, for example, inFIG. 1. Moreover, elongated inlet tube128may also be gripped by the user115to assist handling of beehive treatment device102(seeFIG. 4).

The device described herein may be operated in the following manner:

1. Attach inlet tube128and outlet tube130to the beehive treatment device102. These components may already be attached. In the implementation shown inFIG. 10, the open top acts as inlet tube128.

2. Connect air flow tube134to the source of compressed air136(without opening the air valve150). In implementations where a fan or blower is used, this step is omitted.

3. Connect the device to the electrical power source178(i.e., plug the device into a 120-volt AC electrical outlet or a portable battery pack184supplying DC current). Various implementations may comprise an on-board, rechargeable, portable power source. In such implementations, the device is powered on.

4. Adjust the heating element108to an initial chamber temperature using the variable thermostat180. This step may be user mediated or automatic after providing power.

5. Allow the heating chamber104to reach the selected vaporization temperature.

6. Monitor the heating chamber temperature readout device172and ensure that the heating chamber104is at the optimal operating temperature to get a constant vaporization (for example, 500 degrees Fahrenheit). This step may be user mediated or automatic. It should be noted that introduction of the compressed air will reduce the temperature of the heating chamber104. Improved regulation of the ambient temperature of the heating chamber104may allow reduction in the operation temperature below 500 degrees Fahrenheit. Oxalic acid vaporizes at 372 degrees Fahrenheit; thus, to get a steady amount of vapor, the inner chamber should be heated more than 372 degrees Fahrenheit. In Applicant's experience, a good useable range for vaporization of oxalic acid is between about 400 and about 500 degrees Fahrenheit.

7. Once vaporization temperature is reached, open air valve150to allow compressed air to flow through outlet tube130. Valve150does not need to be fully opened during this step. In those implementations comprising an air flow pre-heat circuit (e.g.,FIGS. 9 and 10), the air flow is heated to prevent recrystallization issues at the outlet tube/air flow interface. In those implementations using a fan or blower, the fan or blower is powered and the air flow rate set. An appropriate air flow regulator is included.

8. The user dons protective gear including an approved breathing mask, which must be worn prior to handling crystalline oxalic acid105to avoid injury.

9. Crystalline oxalic acid105is introduced into the device through the inlet tube128or open top403(seeFIG. 10).

10. The crystalline oxalic acid105is vaporized and discharged through the outlet tube130. If vaporization does not occur, the user verifies that the temperature of the heating chamber104has stabilized at least at approximately 400 degrees Fahrenheit and adjusts the variable thermostat180, as required.

11. If at any time the user sees vapor coming out of the inlet tube128or open top403, the user will increase the air flow rate to prevent backflow of the oxalic acid vapor into the inlet tube128or open top403.

12. The user continues to add crystalline oxalic acid105to inlet tube128or open top403to create a steady vapor stream.

13. Nozzle154of the device is inserted into beehive109near the bottom board (seeFIG. 1) and the oxalic acid vapor is introduced into beehive109until the vapor fumes out at the top.

14. The user treats the next hive.

15. Once hive treatments are completed, the device should be allowed to cool.

16. When cool, inlet tube128and outlet tube130may be optionally removed (unless these components are permanently attached).

17. The device may be cleaned by removing top164or opening top403(seeFIG. 10) and cleaning the inner chamber and the other components. Additionally, air may be blown through outlet tube at a very high air flow rate to flush out impeding material. In the implementation shown inFIGS. 9 and 10, no recrystallization should be minimal or not occur at all near the heated air flow/outlet tube interface.

FIG. 9shows a side view, in partial cut-away section, illustrating alternate beehive treatment device300including an added air flow pre-heat circuit302, according to an implementation of the present disclosure. Pre-heating air reduces recrystallization of vaporized oxalic acid within the outlet tube130, thus allowing continued use of the apparatus without clogging.

Pre-heating of the air is implemented within the air flow pre-heat circuit302, as shown. Alternate air flow tube304is routed within the heating chamber enclosure106prior to discharging at the reduced-pressure generator assembly152. As shown, a portion of air flow pre-heat circuit302is in thermal communication with the heating element108(i.e., the heating element will transfer heat to the air within air flow tube). InFIG. 9, alternate air flow tube304of air flow pre-heat circuit302is coiled around the base of inner pot114, as shown. The coiled portion of alternate air flow tube304may be located in closed proximity to the heating element108, as shown. In the depicted implementation, the coiled portion of alternate air flow tube304is positioned below heating element108, as shown. Upon reading this specification, it should be appreciated that, under appropriate circumstances, other air flow tube arrangements such as, for example, locating a coil in an alternate position within the heated chamber, utilizing an alternate source of heat, including in-line couplers to assist installation or replacement of the tube, etc., may be sufficient.

FIG. 10shows a side view, in partial cut-away section, illustrating alternate beehive treatment device400, according to another implementation of the present disclosure. The configuration of alternate beehive treatment device400varies from the prior-disclosed implementations. First, outlet tube130is joined with exterior wall122of pot114and extends outwardly through a forward exterior wall120of the heating chamber enclosure106, as shown. As with the prior embodiments, the opening of outlet tube130is in fluid communication with interior of the pot114.

Second, a hinged top403is used to cover and seal the inner pot114, as shown. The revised top403includes at least one side-mounted hinge405to allow the top to pivot up and down (as diagrammatically depicted with dashed lines). A latch407(at least embodying herein a securing device to keep top403closed) allows the top403to be secure in a closed position when the device is not in use. When top403is in the open position (a heating chamber inlet) access to the interior of the pot114is provided. Note that the inlet tube128(seeFIG. 9) has been omitted from the top403in this alternate implementation. Top403is in an open state to deposit crystalline oxalic acid into pot114and is left open while oxalic acid is being vaporized (top403left open performs the functions of inlet tube128).

Third, a revised air flow pre-heat circuit402is provided. This alternate air flow pre-heat circuit402includes an air flow tube404that is operably coupled with air flow source409, diagrammatically depicted with dashed lines, which may be compressed air, a fan, blower, or other air flow source. Air flow tube404is routed through the forward exterior wall120of the heating chamber enclosure106, as shown. Once inside heating chamber enclosure106, air flow tube404encircles the base of pot114before passing outwardly from the heating chamber enclosure106, as shown. InFIG. 10, air flow tube404forms a coil located near heating element108, as shown. Thus, it may be stated that a portion of air flow tube404is in thermal communication with heating element108to heat air occupying air flow tube404.

After exiting the heating chamber enclosure106, air flow tube404, carrying heated air, intersects outlet tube130at the reduced-pressure generator assembly152, as shown. Air flow tube404intersects outlet tube130in the manner shown inFIG. 6in the implementation shown inFIG. 10. In the implementation shown inFIG. 10, with top403open, vaporized oxalic acid107is drawn from pot114by moving air and is discharged at the distal end of the outlet tube130, as shown. Upon reading this specification, it should be appreciated that, under appropriate circumstances, considering such issues as user preferences, design preference, structural requirements, marketing preferences, cost, available materials, technological advances, etc., other air flow tube arrangements such as, for example, entering the heated chamber at an alternate point, utilizing an alternate source of heat, adding in-line couplers to assist installation or replacement of the tube, etc., may be sufficient.

Although applicant has described various implementations of the present invention, it will be understood that the broadest scope of this invention includes modifications such as diverse shapes, sizes, and materials. Such scope is limited only by the below claims as read in connection with the above specification. Further, many other advantages of applicant's invention will be apparent to those skilled in the art from the above descriptions and the below claims.