JPS6222575B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of killing rats by asphyxiation using liquid nitrogen, and an apparatus therefor. In general, field mice dig meandering horizontal holes 3cm to 5cm in diameter and 5m to 20m in length in the surface layer of mountains, grasslands, fields, etc., about 1m underground, and build nests with about 3 entrances and exits on the ground surface. It's on. These field mice devour the vegetables and grains in the fields, as well as the bark and roots of trees, causing them to wither.Especially in winter, when they have eaten up all the food stored in their burrows before snowfall, they come out of their burrows to the surface and are exposed to the geothermal heat. As the snow passes through the melting space between the ground surface and the snowfall, it eats away at the bark of trees and causes them to die, causing great damage to fruit trees and other trees. Traditional rat poisoning methods involve placing rodenticide in the passages and holes of field mice, and poisoning them by feeding them. However, rodenticides are not only highly toxic to field mice, but also to humans and livestock, so careful attention is required when handling them. It was impossible for rats to do the work, and the method of poisoning field rats by injecting poison into their burrows poisoned not only field rats but also trees and crops in the field, causing them to wither and become unfit for consumption. It also had the disadvantage that field mice could smell the poison and run away. There is also a method, as in Japanese Patent Publication No. 48-34865, in which a foam containing a gas that can suffocate the rat is pumped into the rat's passage, and the passage is filled with the foam, but the diameter is 3 cm to 5 cm. The length is about 5m to 20
If foam is injected into a meandering mouse burrow, the foam's inherent adhesive force will stick to the wall of the burrow, blocking subsequent foam, and causing the burrow to collapse. It is extremely difficult to inject foam deep into the hole, and even if it were possible to do so, the injection speed would be extremely slow, so rats would notice something abnormal and escape through other entrances. becomes. In addition, if the foam is forcefully fed, it not only destroys the foam but also destroys the rat passages formed in the soft soil, making it impossible to inject the foam. Ta.

The present invention eliminates the above-mentioned drawbacks, and is made by injecting liquefied nitrogen through one of the entrances and exits opened on the ground surface of a rat burrow formed underground, and soiling around the entrance and exit for this inflow. By freezing and solidifying the rods using the latent heat of vaporization of liquid nitrogen and projecting nitrogen gas from other entrances and exits, the inside of the burrow is filled with nitrogen gas and the rats inside the burrow are suffocated to death. The device used in this method consists of a funnel, one end of which is inserted into a doorway opened on the ground surface of a rat burrow formed underground, to allow liquid nitrogen to flow into the rat burrow, and a funnel that isolates the inside of the funnel from the outside air. It consists of a covering body.

Originally, as mentioned above, non-toxic nitrogen gas was used to suffocate rats to death, so it was used in a way that would not cause damage due to toxins as would be the case with conventional poisons used against people, animals, and plants. Even after this, the nitrogen gas, which originally contains 75wt%, diffuses into the atmosphere, so there is no residual effect, making extremely safe rat-killing work possible. In addition, nitrogen gas is tasteless and odorless, and without any resistance to adhesion, it forcibly enters the burrow at high speed and suffocates the field mice without them noticing or giving them time to escape. If there are field mice in the area, you can definitely kill them and make the work more efficient.

An embodiment of the present invention will be described below with reference to the drawings. A mouse burrow 2 formed in the ground 1 has a diameter of 3 to 5 cm and a length of 5 to 20 m, in the surface layer about 1 m underground. Two or three entrances and exits 4 are opened on the ground surface 3. One end of a funnel 5 having a tapered tip is inserted into one of the ports 4 to prevent liquid nitrogen from being injected due to the port 4 collapsing. A covering member 7 is connected to the outer periphery of the funnel 5 in an inverted conical shape by a connecting piece 6 formed of a chain or a fixed connecting rod, and the lower end of the covering member 7 is in contact with the ground surface 3 and the upper end is connected to the outer periphery of the funnel 5. An opening 8 is provided, and a lid 9 is formed in the opening 8 so as to be openable and closable. Further, in the above embodiment, the covering body 7 is formed separately from the funnel 5, but in other different embodiments, a lid body is provided at the inlet 11 of the funnel 5, and this can also be used as a covering body. well,
In short, if the liquid nitrogen injected into the mouse hole through the inlet 11 can be prevented from flowing back into the atmosphere due to the pressure during vaporization, and the vaporized gas can be forced to flow into the mouse hole, the structure is particularly suitable. This is not a problem, and the covering 7 is not required to be airtight in the strict sense. Next, funnel 5
An appropriate amount of liquid nitrogen is injected through the inlet 11, and the lid 9 is closed. The latent heat of vaporization of liquid nitrogen is conducted to the soil around the outer periphery of the funnel 5, and the soil around the outer periphery becomes frozen soil 14 and strengthens the entrance/exit 4, thereby preventing the mouse burrow 2 from being closed due to a landslide.
In addition, the liquid nitrogen injected into the mouse burrow 2 is vaporized by heat exchange upon contact with soil and air, expanding approximately 729 times at room temperature (35°C), and some of this vaporized nitrogen gas is Backflow, inlet 1 of funnel 5
1 tries to flow out into the atmosphere, but is blocked by the covering 7, and a small amount of gas flows out through the inlet 11, but most of it flows into the mouse burrow 2 with a constant expansion pressure. Other entrances and exits in rat burrow 2
5, it flows at a speed of 1m/sec to 10m/sec. After the nitrogen gas flowing through the mouse hole 2 fills the single hole 2, it condenses moisture in the atmosphere and flows out as white smoke 16 through another entrance/exit 15. In this state, it is confirmed that the rat burrow 2 is filled with nitrogen gas, but the rat 17 living in the rat burrow 2 is aware that nitrogen gas is an inert gas that is tasteless and odorless. They do not notice the inflow of gas, and even if they do, they suffocate to death without having time to escape from the single hole 2 because the inflow speed of nitrogen gas is fast.

As described above, the present invention uses liquid nitrogen, which is an inert gas that is inherently non-toxic, to treat rats. It does not cause any negative effects, and even after use, nitrogen gas diffuses into the atmosphere, so there is no residual negative effect.
This enables extremely safe rat killing work. In addition, nitrogen gas is tasteless and odorless, and is forced to flow into a single hole at high speed without encountering any adhesion resistance on the inner surface of a mouse's burrow, without being noticed by field mice or giving them room to escape. It suffocates field mice to death, so if there are field mice in the burrow, they can be killed reliably and efficient work can be done. In addition, since liquid nitrogen vaporizes and expands through heat exchange when it comes into contact with air, nitrogen gas can flow at high speed inside the mouse hole due to its own pressure, and there is no need for a blower or the like to flow the gas. Moreover, they do not require any power to operate, and are often carried out in fields and mountains where electricity cannot be obtained. It is convenient for killing rats. In addition, the latent heat of vaporization of liquid nitrogen is conducted to the soil around the entrance and exit of the liquid nitrogen inflow, and this surrounding soil becomes frozen soil and strengthens the entrance and exit, making it possible to prevent the closing of the mouse hole due to landslides.
This allows liquid nitrogen to flow reliably into a single hole.

Example (1) Liquid nitrogen (100 cc) was injected into a 25 cm x 40 cm plastic bag, and approximately 28 g of a male vole was placed in the plastic bag after waiting for the liquid nitrogen to vaporize. It was confirmed that he died of suffocation.

Example (2) Two voles and one red mouse that had been captured in advance were released into an old single mouse hole that was thought to be no longer in use and had an entrance and exit about 3 meters square. Insert the lower end of the funnel 5 into the entrance of the single hole into which the mouse was introduced, inject 200 c.c. of liquid nitrogen into the funnel 5, and immediately close the lid 9. After 1 to 2 seconds, each part that is thought to be a mouse hole will be removed. White smoke was rising from other entrances and exits, confirming that nitrogen gas was entering an approximately 3m square area.
In addition, 200 ml of liquid nitrogen was added from the other entrance to the rat burrow.
After injecting CC and digging a single hole 20 seconds later, we recovered three rats that had died of suffocation.

Example (3) Test rats were placed in different rat burrows of approximately the same size as in Example (2) under the same conditions as in Example (2) above, and three suffocated rats were found. was recovered.

Example (4) A funnel 5 is inserted into the entrance of a natural mouse hole formed in a meadow, and liquid nitrogen is poured into the funnel 5.
By injecting 200 c.c., white smoke rose from the other entrance and exit, confirming that it was a single hole formed in an area of approximately 2 m x 2 m, and then injecting liquid nitrogen 300 c.c. from two other entrances and exits. By injecting .c. and digging a single hole 30 seconds later, a suffocated carcass of a vole (approximately 30 g) was discovered.

Example (5) A separate mouse hole (approximately 2.5 m) from Example (4) above.
By injecting liquid nitrogen under the same conditions as (4) above into a 2.5 m x 2.5 m area and digging a single hole, a suffocated corpse of a vole weighing 25 g was discovered.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of the present invention. 1... Underground, 2... Mouse burrow, 3... Ground surface, 4... Doorway, 5... Funnel, 7... Covering body,
15...Another doorway, 17...Mouse.

Claims (1)

[Claims] 1. Liquid nitrogen flows into a mouse hole formed underground through one of the entrances and exits opened on the ground surface, and the soil around this entrance and exit is heated by the latent heat of vaporization of the liquid nitrogen. A rat killing method characterized by freezing and solidifying the burrow and reinforcing it, and filling the burrow with nitrogen gas by projecting nitrogen gas from other entrances and exits, thereby suffocating the rats inside the burrow. 2. It consists of a funnel, one end of which is inserted into a doorway opened on the ground surface of a rat burrow formed underground, to allow liquid nitrogen to flow into the rat burrow, and a covering that blocks the inside of the funnel from outside air. Features a rat killing device.