The fourth day of the killing bee aerosol
This special insecticide was first listed in the United States in 1955. At that time, the common insecticide aerosol was to be killed by a very slow, very slow, close to the large flying insects. The usual spray will greatly stimulate the wasp, Hu Feng, they often use their spines to attack any of them. These insects often build nests under the eaves of trees and houses. The nest can be above ground 8m, unless you climb on a ladder near a hive, or a common insecticide is hard to reach. It is clear that a special type of aerosol is needed to control these dangerous insects.
At the beginning, the use of about 3% of the carbon dioxide to the effective use of pesticides, the use of a diameter of 0.50 ~
0.64mm tubular spray hole (not a conical hole) of the nozzle, while the larger diameter of the valve stem and valve body, can produce a thin, long range of the jet. It started forming the center jet thick fog, the road about 1.5 with the look in the eyes of the distance, fog gradually widened, its validity limits in the range of about 3.0~3.5m, which can not meet the expected requirements, and with nitrogen instead of carbon dioxide, aerosol cans only safe to join approximately 0.6% of the nitrogen, indeed, the vast majority of nitrogen in gas phase in the tank there, there have been some technical problems. Because almost no propellant dissolved in the insecticide liquid material. Aerosol pressure broadly in line with's law of Boyle's Law (Bolye); with the volume of the gas phase increases a times, the absolute pressure in the tank dropped to half of the original.
An example might help explain the problem. If you ignore the nitrogen solubility in liquid phase and a raw material liquid filling volume is 66.7% of the net capacity of container, the initial nitrogen pressure is 0.8MPa, when half of the emitting products, the volume of gas phase will increase one times and pressure dropped to 0.35 MPa (gauge). People gradually used to fill in the 0.8MPa nitrogen before the amount of liquid drop to the container's net capacity of about 55%~60%. Boyle's law can be used to calculate the product from the volume of 5% to 55% when the pressure to maintain the tank. When the volume of gas from at the beginning of 45% to 95%, the pressure from the original 0.9MPa (g) to 0.326MPa (gauge). If we consider the trace dissolved in liquid nitrogen, actually the pressure will drop to 0.343MPa (gauge).
Because nitrogen is virtually insoluble in liquid, tubular orifice or straight hole shaped orifice should be satisfactory jets were produced, in addition to the friction of the role of air and in the wall of the tubular injector may have very fine not perfect things, indeed as expected, in the pressure of 0.8MPa, jet in calm air in the effective range is about 7m. As the liquid is ejected, the pressure drop in the tank, the range is shortened, but even in the tank will be sprayed, the range is still about 5m range.
Because these products are only a small amount of propellant, so we must carefully put the cup very tightly sealed in the valve on the tank. The product is also very sensitive to the consumer to try to reverse the tank is also very sensitive. Nitrogen molecules are very small, and are more likely to penetrate the leakage of the packaging than the larger hydrocarbons and two molecules, resulting in a reduction in the amount of gas in the tank, and the pressure drop. Some dealers warn users that they have only a very short time to test these products before using the product to align with the wasps and bees.
Workers often encounter high-voltage wire or the insulator in the hive, they can be located in the taut wire tower or in the power plant, the local cable may with 100 million V, if to the honeycomb spray to kill bee nest inside and outside and safely remove the nests, the product must absolutely dry. The workers had a few accidents when they sprayed with a very small amount of dissolved water. If the water content is more than 40 * 10-6, the current extremely high pressure along the jet to the aerosol cans and users. In these cases, the operator may die from electric shock. These resulted in a class for industrial use "ultra dry" kill bee spray was born. At the same time, all other tags on the killing of bees are printed on the label: This product can not be used for electrical wiring or electrical equipment, if the use may cause the user to get an electric shock.
Although most people think that bumblebee is a special kind of insects, they are actually great family members of wasps. Wasps associated with bee species, such as bees, bee, Bombus Africa. Some pesticides labeled wasp, hornet and killer bee ", especially in recent years, African wild bee colonies in South America and North America sting died and some people with allergies.
In North America, the most common wasps is "Huang Jia Feng" the bee is native to Europe and then with with egg parasitoid of sweet food, wet food were brought to North America. Representative of the adult bee body length 13mm, dark brown body with yellow stripes, hence the name. Its scientific name is Vespa germanica biological. Wasps prefer to live from eaves or about 4~8m tree hive, nest underground maximum, nest cavity can be to 25~30L can persist up to 1.5 million insects and a queen bee and it unhatched eggs, wasp like to eat other insects (especially domestica) therefore, their nests can exist in the barn. Contrary to widely circulated rumors, except when threatened, they rarely sting, they like the bees in the male bee, but is thin.
Unlike the wasp wasp as common, in North America, "bald face" bumblebee is a kind of the only importance. Representative of the bee is about 23mm long, in addition to the small white point, the color dark. They almost always live in a nest that is off the ground.