Sublimation device to protect bees from insects

Abstract

The invention relates to a sublimation device for protecting bees from arthropod pests, which comprises a pot with a heated interior space, a lid and at least one heating means and with a steam outlet pipe. The invention is characterized in that the pot (4) has a thick-walled bottom, in which two intersecting blind holes (11) are formed with their axes lying at an angle to each other, one opening into the heated interior space (6) directly from the bottom of the pot or through the side wall of the pot (4) and the other opening into the exterior space of the pot (4). The bottom outlet pipe (5) is arranged in the blind hole (11) opening into the exterior space of the pot (4), and the steam outlet pipe (2) is arranged in the blind hole (11) opening directly from the bottom of the pot into the heated interior space (6). The end of the steam outlet pipe (2) opening into the interior space (6) is arranged below the lid (3) at a distance therefrom.

Description

[Technical field]

[0001] The present invention relates to an oxalic acid sublimation device adapted for use in apiaries, comprising a pot, at least one heating means and a steam outlet. The sublimation device according to the invention can optimize the sublimation process and significantly reduce the risk of condensation of oxalic acid in the outlet. As a result, the oxalic acid sublimation device allows easier, faster and more energy-efficient operation and requires less maintenance of the oxalic acid sublimation device. [Background technology]

[0002] Asian honeybee mites are one of the most widespread pests of honeybees. Controlling Varroa mites (i.e. reducing their numbers below a given threshold) is very important, since they deteriorate the health of honeybee colonies by spreading viral diseases and, if left uncontrolled, very often lead to colony losses if they multiply. One of the generally accepted mite control methods is oxalic acid sublimation or evaporation (various terms are used: in the English literature the term "evaporation" is more frequently applied, while in Hungarian the method is widely called "sublimation", and the latter term will be used below), in which crystalline oxalic acid (H2C2O4·2H2O) is sublimated at high temperatures (usually 190-230 °C) in a sublimation apparatus and the resulting vapors are introduced inside the hive. When the hot oxalic acid vapor cools and absorbs moisture from the outside, it condenses and forms a thin layer of oxalic acid crystals on the inside surface of the hive, thereby providing mite control. Oxalic acid dihydrate begins to sublime at a temperature of 157°C. However, when oxalic acid dihydrate is heated above a temperature of 235-240°C, it gradually transforms into formic acid, which is harmful to honeybees.

[0003] Beekeepers use appropriately configured equipment to carry out the above-mentioned oxalic acid treatment. The prior art includes various technical solutions for sublimation. The present invention improves on this solution, in that the heated pot is sealed during the sublimation process, except for the outlet tube, and when the oxalic acid dihydrate is sublimated by heating, an overpressure is created in the pot, and the oxalic acid vapor is released from the pot and introduced into the beehive through the outlet tube of the pot.

[0004] The prior art device is described in relation to Figures 1 and 2. The pot 4 of the device is made of metal with good heat conducting properties. The most frequently used heating element is a cylindrical band heater (also called a clamp heater) attached to the outside of the pot 4. A temperature sensor is placed in a hole 7 located at the bottom of the cylindrical pot 4. This sensor is used to control the band heater by switching it on and off to keep the pot 4 at the desired temperature. The upper outlet pipe 9, which releases oxalic acid vapor under pressure, is placed on the cylindrical side of the pot 4 near the lid of the pot 4. The reason why the upper outlet pipe 9 needs to be placed at the top end of the pot 4 is that otherwise (i.e. if the outlet pipe is located at the bottom), the crystallized water contained in the oxalic acid dihydrate placed in the internal space of the pot 4 will boil first, and therefore the oxalic acid will leave the pot in a liquid state. However, since the upper outlet pipe 9 starts from the top of the pot 4, the oxalic acid can only escape as vapor. Two types of arrangements are generally prevalent. In one arrangement, the oxalic acid is discharged through an upper discharge pipe 9 (such a solution is applied in the Oxalika PRO device presented on the Internet site (https: / / www.talitha-info.com / ?lang=hu)). In the case of another prior art solution, the oxalic acid leaves the device through a curved discharge pipe 10 (such a solution is applied in devices such as SzublimOx, Varroa-Ox, Provap, etc., found on the Internet site (http: / / www.citovar.hu / termekkategoria / szublimalas / szublimalashoz-kijuttato-eszkozok / )).

[0005] In this technical solution, a curved discharge pipe 10 extending horizontally or diagonally from the upper end is bent downwards and then bent again by 90 degrees at the point where it reaches the bottom of the pot 4, so that the device can be applied to carry out the sublimation process also from an inlet located at a low position of the hive (with a landing board).

[0006] A similar solution is disclosed in patent US 10,757,921 B1, which also applies band heating and the oxalic acid vapor is discharged through an upper exhaust pipe protruding from the pot lid.

[0007] Another prior art technical solution is presented in utility model specification TW20190213843, where the cylinder side is heated by a burner, and the steam exhaust pipe passes through the cylinder surface and under the pot (from the outside) and has a curved shape at the bottom.

[0008] The above-mentioned device, which applies the most widely applied technical solutions, may have the following operational malfunctions:

[0009] Applying a band heater is not optimal because when oxalic acid is fed into the device, it falls to the bottom of pot 4 and takes heat from there. As a result, the temperature sensor detects the temperature drop and switches on the band heater. However, the heat provided by the band heater reaches the bottom of pot 4 with a long delay (the control has a large time constant) and as practical experience shows, this leads to significant overheating or, in the case of PID temperature control, a delayed rise in temperature and large temperature fluctuations.

[0010] In the first solution, the upper discharge pipe 9 is attached to the relatively thin cylindrical wall of the pot 4, so that it cannot be heated sufficiently, i.e. its end tends to cool to a critical temperature at which part of the oxalic acid vapor flowing through it condenses, which (sooner or later) causes the tube to become blocked. Removing the condensed oxalic acid is a time-consuming task. In bad weather (cold and windy), the frequency of blockages is even higher. The location of the upper discharge pipe 9 is not optimal, since to ensure that the oxalic acid is released only in a vapor state, the discharge pipe must be located at the top end of the pot 4, but its end is preferably located at the bottom of the device, where it is accessible to the outlet of the beehive above the landing board. The result is the same if, as in the second solution, the oxalic acid vapor is introduced into the beehive through a curved discharge pipe 10. The length of the curved discharge pipe 10 is located and extends into the external space, and its curved shape makes it easier for the curved discharge pipe 10 to cool and therefore to become blocked. On the other hand, the curved shape makes cleaning the tube (which is time consuming in itself) more difficult and tedious. Additionally, bending, brazing and / or welding the curved exhaust tube 10 is a labor intensive and time consuming process.

[0011] Another drawback of the solution with a curved exhaust pipe 10 is that because the pipe is made of a soft metal, usually soft copper, to obtain its required curved shape, the exhaust pipe becomes even softer over time and tends to break during use.

[0012] The object of the present invention is to provide an improved outlet for releasing oxalic acid vapors by eliminating the drawbacks of the prior art solutions, and to provide a more optimal heating system and a pot having these improved characteristics and capable of continuous production.

[0013] The invention is based on the realization that sublimation through the honeycomb outlet can be carried out in a more favorable manner if the outlet is located near the bottom of the pot and if it is made of a material with sufficient strength and at the same time as short and as simple as possible. We also realised that the interior of the pot can be designed in such a way that boiling oxalic acid dihydrate cannot escape through the outlet located at the bottom, i.e. only oxalic acid vapor can leave the device. We further realised that by providing an outlet path as short as possible and locating it as close as possible to the heating means, suitable temperature conditions are obtained, so that the temperature required to prevent condensation of oxalic acid can be adequately ensured. DISCLOSURE OF THEINVENTION

[0014] The technical solution according to the invention is therefore a sublimation device for protecting bees from arthropod pests, said device comprising a pot with a heated interior space, a lid and at least one heating means and with a steam outlet pipe. The invention is characterized in that the pot has a thick-walled bottom, in which two intersecting blind holes are formed with their axes lying at an angle to each other, one opening into the heated interior space directly from the bottom of the pot or through the side wall of the pot and the other opening into the exterior space of the pot. A bottom outlet pipe is arranged in the blind hole opening into the exterior space of the pot. Also, a steam outlet pipe is arranged in the blind hole opening into the heated interior space directly from the bottom of the pot. The end of the steam outlet pipe opening into the interior space is arranged below the lid and at a distance therefrom.

[0015] According to a preferred embodiment of the invention, the intersecting blind holes are perpendicular to each other.

[0016] According to another preferred embodiment of the invention, the steam discharge pipe consists of a blind hole which opens through the side wall of the pot into the heated interior space, or the steam discharge pipe is arranged in said blind hole.

[0017] Another preferred embodiment of the invention is characterized in that the heating means are implemented as at least one, preferably at least two heating cartridges, which are preferably arranged laterally to the bottom discharge pipe.

[0018] In a further preferred embodiment of the invention, the lid is provided with an oxalic acid drop tube adapted to facilitate the supply of oxalic acid into the device.

[0019] In another preferred embodiment of the invention, a hole adapted to receive a temperature sensor is located below the heated interior space of the pot. [Brief description of the drawings]

[0020] In the following, a sublimation device according to the invention will be described with reference to an exemplary embodiment, with reference to the accompanying drawings, in which: FIG.

[0021] [Figure 1] FIG. 1 shows a cross-sectional view of a prior art solution currently available on the market, with a straight exhaust pipe attached at the top end.

[0022] [Diagram 2] FIG. 2 shows a cross-sectional view of a currently widely applied prior art solution with a curved exhaust pipe.

[0023] [Diagram 3] FIG. 3 shows an axonometric section of the pot of the device according to the invention.

[0024] [Figure 4] FIG. 4 is a cross-sectional view of a pot of a device according to the invention.

[0025] [Diagram 5] FIG. 5 shows the location of the bottom outlet and heating cartridge of the pot of the device according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Figures 1 and 2 show the configuration of the pot applied in the prior art device mentioned above in the background section. As can be seen in Figures 3 and 4, the pot 4 of the sublimation device according to the invention is equipped with a thick-walled bottom having a thickness of 7 to 50 mm, preferably 30 mm in the exemplary embodiment, and contains a heated interior space 6. In the thick-walled bottom of the pot 4, two intersecting blind holes 11 are formed such that the axes of the blind holes 11 are located at an angle to each other, advantageously perpendicular to each other, where one hole opens into the heated interior space 6 directly or through a side wall of the pot 4, and the other hole opens into the exterior space of the pot 4. In the (preferably horizontal) blind hole 11 opening into the exterior space of the pot 4, a bottom discharge pipe 5 is arranged. The bottom discharge pipe 5 is adapted to convey oxalic acid vapor to the inlet of the honeycomb. In an exemplary embodiment, at least one, but preferably two, heating cartridges 8 are arranged on both sides of the bottom discharge pipe 5 (see FIG. 5), which surround the bottom discharge pipe 5 and heat it in close proximity. The heating means may be band heaters, since by arranging the pipes according to the invention, the required function can also be achieved while applying band heating. Furthermore, the steam discharge pipe 2 is arranged in a (preferably vertical) blind hole 11 which opens directly into the heated interior space 6. If a (conveniently vertical) blind hole 11 is formed in the side wall of the pot 4, it is possible to implement the invention in such a way that the steam discharge pipe 2 is configured in this blind hole 11. The steam discharge pipe 2 and the bottom discharge pipe 5 can be fixed in the blind hole 11 by pressing, by a screw connection or in any other way that is obvious to the skilled person. Due to the crossing configuration of the blind holes 11, the oxalic acid vapors can freely escape through the blind hole 11 under pressure. The length of the steam discharge pipe 2 is selected so that it does not come into contact with the lid 3 attached to the pot 4, i.e. it is spaced therefrom. If a blind hole 11 opening into the interior space 6 is formed in the side wall of the pot 4, this blind hole communicates with the interior space 6 through an opening located just below and spaced from the lid 3.Such a configuration ensures that the oxalic acid vapors 2 enter the vapor discharge tube while at the same time preventing the oxalic acid liquid boiled in the crystallization water by heating from escaping through the tube. Advantageously, the oxalic acid drop tube 1 is arranged in the lid 3 to facilitate the feeding of oxalic acid into the device. After the oxalic acid has been fed into the device, the drop tube 1 is sealed so that the pot 4 can be pressurized and the oxalic acid vapors can only escape through the bottom discharge tube 5. Advantageously, near the heating means (in our example, two heating cartridges 8) below the heated inner space 6 of the pot 4, a hole 7 is arranged to switch the heating means on and off based on the measured temperature value.

[0027] The device according to the invention has the following advantages:

[0028] The temperature drop caused by the oxalic acid dihydrate supplied to the heated inner space 6 is detected by a temperature sensor located directly below the heated inner space 6, which in turn turns on the heating cartridge 8. In this way, temperature control with a fast response time (low time constant) can be achieved.

[0029] Regardless of the temperature of the exterior space, the steam discharge pipe 2 is located in the heated interior space 6 and therefore cannot cool down, preventing oxalic acid from condensing therein.

[0030] The bottom discharge pipe 5 starts from the thick-walled bottom of the pot 4 and is located directly between the two heating cartridges 8, so that it is less likely to cool and therefore less likely for oxalic acid to condense in it.

[0031] The bottom discharge pipe 5 is configured to be separate from the discharge pipe, is not curved or bent and can be easily machined. As such, the bottom discharge pipe is adapted to support the weight of the entire device and is therefore advantageously manufactured from a material (e.g. copper, brass, etc.) of such strength that it is also able to withstand the mechanical loads caused by the weight of the device during operation.

[0032] The solution, which includes a bottom discharge pipe 5, allows the sublimation of the bee colony through the hive outlet.

[0033] The device according to the invention can be manufactured using common CNC machining techniques, i.e. no hand labor, soldering or welding is required.

[0034] For larger series production the arrangement can be modified so that the separately machined steam discharge pipe 2 shown in the drawing can conveniently be manufactured by moulding or even as a cavity formed in the wall of the pot 4.

Claims

1. 1. A sublimation apparatus for protecting honeybees from arthropod pests, said apparatus comprising a pot having a heated interior space, a lid and at least one heating means, said pot having a steam exhaust pipe; the pot (4) has a thick-walled bottom, in which two intersecting blind holes (11) are formed with their axes at an angle to each other, one of the holes opening into the heated internal space (6) directly from the bottom of the pot (4) or through a side wall of the pot (4) and the other opening into the external space of the pot (4), a bottom discharge pipe (5) is arranged in the blind hole (11) opening into the external space of the pot (4), a steam discharge pipe (2) is arranged in the blind hole (11) opening directly from the bottom of the pot into the heated internal space (6), the end of the steam discharge pipe (2) opening into the internal space (6) is arranged below the lid (3) at a distance therefrom, Sublimation equipment.

2. characterised in that the intersecting blind holes (11) are perpendicular to each other, 2. The sublimation apparatus of claim 1.

3. characterised in that the steam discharge pipe (2) is constituted by the blind hole (11) which passes through the side wall of the pot (4) and opens into the heated interior space (6), 2. The sublimation apparatus of claim 1.

4. a steam discharge pipe (2) is arranged in the blind hole (11) which passes through the side wall of the pot (4) and opens into the heated interior space (6), 2. The sublimation apparatus of claim 1.

5. characterised in that the heating means are implemented as at least one, preferably at least two heating cartridges (8), preferably arranged laterally of the bottom discharge pipe (5), 2. The sublimation apparatus of claim 1.

6. The cover (3) includes an oxalic acid drop tube (1) adapted to facilitate the supply of oxalic acid into the device.

2. The sublimation apparatus of claim 1.

7. characterised in that a hole (7) adapted to receive a temperature sensor is arranged below the heated interior space (6) of the pot (4), 2. The sublimation apparatus of claim 1.

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