JP7090276B2 - Electrostatic field screen for pest control - Google Patents

Description

The present invention relates to an electrostatic field screen for pest control, and more specifically, a static electrostatic field screen for pest control suitable for use in windows of livestock facilities (livestock barns) such as piggery and openings such as ventilation fans. It is about.

In modern barn design, it is necessary to ensure adequate ventilation. It is important that the barn is designed to remove excess heat, water vapor, dust, gas, and odors, and that the air is evenly distributed. Passive or natural ventilation is provided by the supply and removal of air through the openings of the building. Natural ventilation is caused by the natural flow of wind around the building and the temperature difference between the inside and outside of the building. Forced ventilation is caused by a fan, an automatic temperature controller, and an air intake, and most commonly, a fan is used to blow air out of the building and fresh air from the other side. It is done by sucking through. Fans can also be installed in the facility to circulate air and improve the uniformity of ventilation properties.

However, if ventilation is adequate, pests can be introduced into the barn. Serious pest problems in livestock production are wide-ranging. Livestock pests feed on the animal's blood, skin, and hair, and pest bites can cause physical and mental health problems for the animal. In addition to the problem of pests in livestock, there is also concern about the transmission of pathogens from the barn to the surrounding human society through pest transmission. In many parts of the world, the rapid pace of urbanization has forced the urban livestock industry to feed urban dwellers. Therefore, the risk of infectious diseases common to humans and animals occurring in urban areas is becoming more and more serious.

In this way, in the barn, it is necessary to secure sufficient ventilation and take measures to prevent the invasion of pests, but between these two requests, if the ventilation equipment is sufficient, the pests will be installed. Since there is a contradictory aspect that it may be introduced inside, no equipment suitable for installation in a livestock facility such as a piggery has been proposed so far that can satisfy these two requirements at the same time.

Japanese Unexamined Patent Publication No. 2007-195404

As mentioned above, conventionally, no equipment suitable for installation in a barn such as a piggery has been proposed, which can simultaneously satisfy the two requirements of ensuring sufficient ventilation and preventing the invasion of pests. Its appearance was coveted. The present invention has been made in order to meet such a demand, and it can be supplied at a relatively low cost with a simple structure. By installing it in an opening such as a window of a livestock barn such as a pig barn, sufficient ventilation is ensured and pests are pests. It is an object of the present invention to provide an electrostatic field screen for pest control that exerts a function of preventing the invasion of.

The present inventors have obtained the finding that it is possible to kill pests by using high-energy electrons generated in an electric field, and due to the high conductivity of the pest body, only the pests are electrocuted by the arc discharge generated instantly in the device. As a result of diligent research and testing under the hypothesis that it will die, the present invention has been completed.

That is, in the invention according to claim 1 for solving the above-mentioned problems, three stainless steel nets of the same size and the same mesh, that is, a central net and an outer net arranged on both sides thereof, are placed in an insulating frame. The central nets are negatively charged and the outer nets are positively charged so that the opposite poles face each other by arranging them in parallel while maintaining a predetermined distance between the nets.
The applied voltage to the central net is less than 10.1 kV, and the difference between the applied voltage to the central net and the applied voltage to each of the outer nets arranged on both sides thereof does not cause forced discharge between the nets. It is a range, and the mesh size of the three nets is the same size for 4 meshes or more, and the distance between the three nets is about 15 mm.
It is an electrostatic field screen for pest control, characterized in that it is possible to electrocut the pest by an arc discharge generated instantaneously by the pest having high conductivity entering between the nets.

In one embodiment, a spacer made of an insulating material for maintaining the distance between the electrodes is sandwiched between the nets of the three nets.

Since the electrostatic screen for pest control according to the present invention is as described above, it can be supplied at a relatively low cost with a simple configuration, and sufficient ventilation can be provided by installing it in an opening such as a window of livestock equipment such as a piggery. It has the effect of ensuring and preventing the invasion of pests.

It is a schematic diagram which shows the schematic structure of the electrostatic field screen for pest control which concerns on this invention. It is a schematic diagram which shows the electric field in the electrostatic field screen for pest control which concerns on this invention. It is a figure which shows the test method performed in order to confirm the action effect of the electrostatic field screen for pest control which concerns on this invention. It is a figure which shows the test method performed in order to confirm the action effect of the electrostatic field screen for pest control which concerns on this invention. FIG. 5 is a graph showing the relationship between the applied voltage of three different types of electrostatic field screens according to the present invention under different relative humidity (RH) conditions and the magnitude of the current generated by the silent discharge from the central net.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1, the pest control electrostatic field screen according to the present invention is made of three sheets of stainless steel of the same size and the same mesh, that is, the central net 1 and the outer nets 2 and 3 arranged outside the central net 1. The metal nets are arranged in parallel with a predetermined interval between the nets 1 to 3. Then, the central net 1 is connected to, for example, a DC voltage generator 4 having a maximum current of 1,000 μA and negatively charged, and the outer nets 2 and 3 are connected to the ground wire 5 and are connected to the central net 1. It is configured to be positively charged by electrostatic induction so that the opposite poles face each other.

The three nets 1 to 3 are assumed to be installed in the window of a barn, for example, and have a mesh size of 4 mesh or more in order to ensure sufficient ventilation, and each has an insulating frame made of polycarbonate or the like. Surrounded by 6. Further, a spacer 7 made of an insulating material such as polypropylene having a thickness corresponding to the distance between the electrodes is interposed between the nets 1 to 3 to secure the distance between the electrodes. The distance between the electrodes is, for example, around 15 mm.

In the case of this configuration, between the central net 1 and the outer net 2, the central net 1 side is negatively charged, and the outer net 2 side is positively charged by electrostatic induction. Is formed. Similarly, between the central net 1 and the outer net 3, the central net 1 side is negatively charged, so that the outer net 3 side is positively charged by electrostatic induction, and an electric field is formed between the two nets 1 and 3. (See Fig. 2). The arrows in FIG. 2 indicate the direction of the electric current.

As described above, the apparatus according to the present invention was developed under the hypothesis that due to the high conductivity of the pest body, only the pest will be electrocuted by the arc discharge generated instantaneously in the apparatus. .. The present inventors confirm that this hypothesis is correct, perform the following tests to determine the effectiveness of the device, and obtain the most appropriate conditions from the test results to optimize the configuration of the device. I decided to make it.

Test material The common house mosquito was used as a model vector for viral pathogens. Adult common house mosquitoes were bred in a growth chamber at 25.0 ± 0.5 ° C. and 4,000 looks under a photoperiod of 12 hours. Then, in the following experiments, newly emerged adults of the common house mosquito were used. The average body size of the adult house mosquito (that is, the average length from the head to the tip of the wing in 20 adults) was 5.6 ± 1.3 mm.

Test equipment As a test equipment, according to the present invention, three stainless steel nets of the same size and the same mesh are arranged in parallel between each net 1 to 3 while maintaining a predetermined interval, and a DC voltage is generated in the central net 1. I prepared the one with the vessel 4 connected. In this test device, a galvanometer 8 for measuring the movement of free electrons to the central net 1 was connected to each ground wire 5 (see FIG. 1). Further, as a test device, three types of electrostatic screens having different net sizes, that is, 45 × 45 cm (S screen), 90 × 90 cm (M screen), and 180 × 90 cm (L screen) were prepared.

≪Experiment 1≫
In the first experiment, three types of screens were charged with 1 to 15 kV, and forced discharge (arc discharge) was performed from the central net 1. In addition, silent discharge (which is constantly occurring on the outer net 2 and 3 side surfaces of central net 1) was measured in a voltage range (2.0 to 10.0 kV) where forced discharge did not occur. The current was measured by the galvanometer 8 as a total of silent discharge and forced discharge, or as a pest-mediated discharge described later. Experiments were performed at 25 ° C. and under different relative humidity (RH) conditions (30, 60, and 90%).

≪Experiment 2≫
In the second experiment, the three screens were charged with different voltages (2-10 kV), and the range of voltage to electrocut all the pests introduced into the screen and the pest-mediated transient current at the given voltage ( The magnitude of (caused by arc discharge) was determined. The common house mosquito, which is the insect to be tested, was collected by an insect aspirator and blown into the net by blowing compressed air through the tip of the insect aspirator (Fig. 3). The wind speed was measured on the surface of the central net 1 using a high-sensitivity anemometer.

In these experiments, the common house mosquito was blown at a wind speed of 3-5 m (average air flow rate in a well-ventilated piggery). All experiments were performed under the above RH and temperature conditions. Galvanometer 8 recorded the pest-mediated discharge as a transient current. The common house mosquito evaluated its mortality after passing through an electric field. Twenty adult common house mosquitoes were used for each voltage and RH condition tested. The experiment was repeated 5 times, the data were shown as mean and standard deviation (SD), and significant differences between treatments were determined using Tukey's method.

Test Results and Examination In the above test apparatus, both electrodes were charged by negatively charging the central net 1 using the high voltage generated in the Cockcroft circuit in the voltage generator 4 and discharging from the outer nets 2 and 3. The flow (current) of the stored electricity to the central net 1 depends on the voltage applied to the electrodes, the distance between the electrodes, and the conductivity of air between the two electrodes. The current was proportional to the increase in voltage and inversely proportional to the increase in distance. The conductivity of air varies in response to fluctuations in the concentration of water vapor (RH) in the air and becomes higher as the RH increases (ie, the amount of electrical transfer increases). In this experiment, the distance between the electrodes was fixed, the voltage was effectively changed, and the common house mosquito was electrocuted by an electrostatic device under different RH conditions.

In Experiment 1, the voltage at which forced discharge occurs from the central net 1 due to the non-uniform structure of nets 1 to 3 used for the screen was measured. The forced discharge (arc discharge) occurred at a protruding point on the central net 1. As the voltage applied to the central net 1 was increased, the screen eventually produced a forced discharge at ≧ 10.1 kV, regardless of changes in RH. As a result, it was found that the screen can be operated at <10.1 kV without causing a forced discharge even if there is a change in RH.

In the electric field generated between the nets, a silent discharge was constantly generated from the outer nets 2 and 3 side surfaces of the central net 1 toward the outer nets 2 and 3. FIG. 5 shows the relationship between the applied voltage and the occurrence of silent discharge. In all types of screens of different sizes, the current generated by this discharge increases in direct proportion to the increase in the applied voltage, and the range of the applied voltage at that time is 6.8 to 10 kV, M for the S size screen. The size screen was 4.3 to 10 kV, and the L size screen was 3.2 to 10 kV. The current increased as the screen net size increased. In addition, the current increased with increasing RH on all screens tested.

In the electrostatic field screen according to the present invention, it was considered that the air in the electric field was ionized by ionization, so the measurement was performed by an ion detector. As a result, it was found that the air in the electric field was ionized by ionization. It was also confirmed that the ionized air in this electric field is very active, can destroy or inactivate various microorganisms including viruses, and can deodorize malodorous gas passing through the electric field. rice field. Various malodors generated in the barn cause serious environmental problems, and the electrostatic field screen according to the present invention can be effectively utilized as a countermeasure against the malodor due to this malodor removing ability.

In the second experiment that follows, a conductor that uses various voltages that do not generate forced discharge from the central net 1 and that transmits electricity (free electrons) according to its capacity was introduced into the space between the nets of the screen. The inventors' hypothesis is that this conductor material can act as a temporary acceptor of electrons from the central net 1 and as a donor of electrons to the outer nets 2 and 3 by reducing the distance between the electrodes. It was that.

Insects (common house mosquitoes) were good biological conductors in tests to confirm the validity of this hypothesis (Fig. 4). That is, it is known that the epidermis, which is the outer protective layer covering the body of many vertebrates, is efficiently charged by its high conductivity, and the adult house mosquito has this epidermis structure. Because it is.

Table 1 lists the magnitudes of the instantaneous transient currents mediated by the adult house mosquito introduced into the test equipment. Each net 1 to 3 was charged with different voltages (2 to 10 kV) under different RH conditions. Once the common house mosquito is introduced, electrons move instantaneously from the central net 1 to the outer nets 2 and 3, and within the voltage range of 3 to 10 kV for the L and M screens and 4 to 10 kV for the S screen, the common house mosquito is introduced. It was decided to escape to the earth through. This electron transfer was simultaneously recorded by two galvanometers 8 as transient currents of the same magnitude. However, the magnitude of the current was significantly different between the screens used, even when the same voltage was applied.

These results indicate that different amounts of electricity (free electrons) stored in the central net 1 were emitted towards the pests. The magnitude of the increase in current corresponds to an increase in the area of the central net 1 (ie, an increase in the capacitance of the central net 1). In all screens, the magnitude of the current increased as the applied voltage increased. The higher the current, the greater the impact, pushing the common house mosquito out of the air. The RH condition did not cause any significant difference in insect-borne transient currents on all screens.

Table 1 also shows the mortality rate of the common house mosquito introduced into the screen. The lowest voltages that could kill all common house mosquitoes by electric shock were 4, 6, and 8 kV on L, M, and S size screens, respectively. At these voltages, insect-mediated transient currents of similar levels (approximately 20 μA) were generated, and it was found that this level of current was required for effective electrocution of insects in the screen's electric field. .. At lower voltages, the resulting electric shock was insufficient to kill the insects, as the accumulation of free electrons in the central net 1 was less.

<Table 1>

The results obtained from the above test results are as expected by the present inventors, and the apparatus according to the present invention is applicable to prevent the common house mosquito transmitting the virus from escaping from the barn. It was a confirmation. It is clear that this device is also effective in preventing pests from invading the barn, that is, protecting livestock and the like in captivity from various pests. Theoretically, this pest control method is applicable to all pests having a conductive epidermal layer. Controlling ectoparasites is one of the most expensive and time-consuming tasks in livestock pest control, and in warmer regions, various flies are ectoparasites to animals.

The apparatus according to the present invention not only has the ability to electrocut pests, but also can secure a sufficient opening area for ventilation by using a net having a wide opening area. The mesh size of the net (for example, 7.0 mm mesh) is considerably larger than that of the conventional woven pest net (0.8 to 1.5 mm mesh). When this conventional woven pest net was installed in the opening of the same barn where this device was installed in the above experiment, the ventilation efficiency was surely lowered as a matter of course.

In the above test apparatus, in both arc discharge and silent discharge, the current increased in direct proportion to the applied voltage, RH (only in the case of silent discharge), and the increase in net size. These properties are due to the electrostatic properties of the screen. However, the magnitude of the current (20-200 μA) was negligible from a practical point of view. As described above, the electric field is formed between the negative charge of the central net 1 and the positive charge of the outer nets 2 and 3 on the central net 1 side, and the outer surface of the outer nets 2 and 3 has no charge. I was able to safely touch the surface of the net. As another protective measure, there is a current limiter (maximum limit value is 1000 μA) incorporated in the electric circuit of the voltage generator 4, which is the voltage generator 4 when an excessive current is generated due to an unexpected situation. Is automatically turned off.

The apparatus according to the present invention can be used for efficient pest control in a barn and can eliminate the need for pesticide treatment. In addition, the device according to the present invention has a simple structure, is easy to manufacture without requiring special technology, is easy to adjust the size according to the installation location, operates with low power consumption, and transmits a pathogen virus. It is capable of electric killing pests that may cause pests, is suitable for installation in the opening of livestock breeding facilities for pest control, eliminates the need for pesticide treatment, and is environmentally controlled. It makes it possible to raise and supply virus-free animals in livestock facilities, and its industrial utility is extremely high.

1 Central net 2, 3 Outer net 4 Voltage generator 5 Grounding wire 6 Insulated frame 7 Spacer 8 Galvanometer

Claims (2)

Three stainless steel nets of the same size and the same mesh, the central net and the outer nets arranged on both sides thereof, are arranged in parallel in the insulating frame with a predetermined space between the nets, and the central net is arranged in parallel. Is negatively charged, and the outer nets are positively charged so that the opposite poles face each other.
The applied voltage to the central net is less than 10.1 kV, and the difference between the applied voltage to the central net and the applied voltage to each of the outer nets arranged on both sides thereof does not cause forced discharge between the nets. It is a range, and the mesh size of the three nets is the same size for 4 meshes or more, and the distance between the three nets is about 15 mm.
An electrostatic field screen for controlling pests, which is capable of electrocuting the pests by an arc discharge generated instantaneously when a pest having high conductivity enters between the nets. The electrostatic field screen for pest control according to claim 1, wherein a spacer made of an insulating material for maintaining a distance between electrodes is sandwiched between each of the three nets.

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