JP3850333B2 - Propellant - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a propellant, in particular, using a propellant obtained by mixing prill ammonium nitrate and polyoxymethylene without using highly evaporable alcohol, and using conventional alcohol vaporization and molarity with ammonium nitrate by evaporation. In order to eliminate the disadvantage of fluctuation of the ratio, to make the average molecular weight of the reaction product smaller than the molecular weight of water, to increase the speed of the flying object, and to be able to be accommodated in a simpler container than before and to maintain a long life. It relates to a new improvement.
[0002]
[Prior art]
Conventionally, as this type of propellant used, a composition in which the average molecular weight of the reaction product after combustion of the propellant was 20 or more than the molecular weight of water was used, so the velocity of the projectile was 1500 m / sec. It was difficult to exceed 1600 m / sec. Recently, in the Ikuta report (Japanese Patent Laid-Open No. 11-29388 and Jpn. Appl. Phys. Vol 36, pl 413, 1997), when the average molecular weight of the reaction product is water or less, the projectile velocity is 1700 m / It is found that the second is reached. of Propulsion and Power Vol17, No. 1, P120 (2001). The propellant having an average molecular weight of the reaction product equal to or lower than the water molecular weight is conventionally a mixture of ammonium nitrate and ethyl alcohol or methyl alcohol (disclosed in JP-A-2001-26491), and the mixing molar ratio of alcohol and ammonium nitrate is By selecting 1: 2-80, the maximum value of the outlet speed of the launch tube was obtained.
That is, the velocity V of the flying object is proportional to the square root of the ratio of the driving gas temperature T to the average molecular weight A (V （√ (T / A)). A propellant that raises or generates a gas with a low average molecular weight is needed. The above-mentioned alcohol- ammonium nitrate mixture can change the average molecular weight to 9-23 by changing the mixing ratio of alcohol and ammonium nitrate, and the calorific value (temperature) also changes at the same time. The highest firing rate was obtained, and this value was experimentally when the alcohol-to-nitrate mixture molar ratio was 1: 2-80.
[0003]
[Problems to be solved by the invention]
In the conventional high-performance propellant mixture of ammonium nitrate and alcohol, the alcohol component tends to evaporate and evaporate, so to prevent it, a special sealed container configuration is used. It was difficult.
[0004]
The present invention has been made in order to solve the above-described problems, and in particular, using a propellant obtained by mixing prill ammonium nitrate and polyoxymethylene without using a highly evaporable alcohol, Eliminates the drawbacks of changing the molar ratio with ammonium nitrate due to vaporization and evaporation of alcohol, makes the average molecular weight of the reaction product smaller than the molecular weight of water, speeds up the flying object, and makes it easier than before It is an object of the present invention to provide a propellant that can be housed in a container and can maintain a long life.
[0005]
[Means for Solving the Problems]
The propellant according to the present invention is obtained by mixing prill ammonium nitrate and polyoxymethylene, and has a constitution in which the polyoxymethylene is 4 mol or more per 1 mol of the prill ammonium nitrate. The average particle size is in the range of 50 μm to 2000 μm.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a propellant according to the present invention will be described with reference to the drawings. FIG. 1 shows a launching device 10 for launching a flying object 8 using a propellant 1 according to the present invention.
In FIG. 1, a propellant 1 is loaded into a metal cylinder 2, and a flying object 8 such as a bullet is loaded at the tip of the propellant 1.
A metal rod 4 is attached to the rear end side of the propellant 1 via a cylindrical insulator 3. Between the metal rod 4 and the metal cylinder 2, aluminum or the like located in the propellant 1 is used. A fuse 7 is provided.
[0007]
A capacitor bank 5 as a power source is connected between the metal rod 4 and the metal cylinder 2 via a switch 6.
The propellant 1 is formed by powder mixing 5 mol of polyoxymethylene polymer having an average particle diameter of 50 μm with respect to 1.25 mol of prill ammonium nitrate.
The polyoxymethylene polymer is preferably 4 mol or more, and the average particle size (average particle size) is preferably in the range of 50 μm to 2000 μm.
[0008]
The molecular structure of this polymer suitable as a combustion component is a chain polymer of [—CH ₂ O—] n, and when this polymer is subjected to thermal decomposition, [CHO—] (formaldehyde group) groups are successively formed from the end groups. It was found that this group was further decomposed by the rapid combustion heat with prill ammonium nitrate, and the decomposition gas smaller than the water molecular weight was the main component. The average molecular weight of the product gas is almost the same as that of water when the molar ratio of ammonium nitrate to polyoxymethylene is 1: 4. Therefore, it is necessary to mix so that the ammonium nitrate amount does not exceed this value. Therefore, it is necessary to mix 4 mol or more of polyoxymethylene with respect to 1 mol of prill ammonium nitrate. When polyoxymethylene is thermally decomposed by electric heating, the contribution of combustion heat decreases when the mixing ratio of prill ammonium nitrate decreases, so optimization of the power to be supplied and the amount of ammonium nitrate is important.
[0009]
Next, the performance of the propellant 1 was examined with the launching device 10 shown in FIG. The charging voltage of the capacitor bank 5 is 10,000 volts and the stored energy is 100 kilojoules. When the capacitor 6 is charged and then the switch 6 is closed, the fuse 7 composed of an aluminum wire connecting between one end of the metal rod 4 located in the reaction chamber and the inner wall surface of the metal cylinder 3 exceeds 100 kiloamperes. The current flowed and the fuse 7 was melted and evaporated to shift to arc discharge. This propellant 1 decomposed with high heat to generate a high-temperature gas having an average molecular weight of 18 or less to accelerate the flying object 8. The arrival speed in this case was 1900 m / sec.
[0010]
【The invention's effect】
Since the propellant according to the present invention is configured as described above, the following effects can be obtained.
In other words, since the propellant is composed of prill ammonium nitrate and solid polyoxymethylene consisting of the same low-molecular elements as alcohol, there is no change in weight due to evaporation unlike alcohol, and a special container for sealing the liquid is necessary. Therefore, the container can be made inexpensive and a product with little aging and long life can be obtained.
Further, since the average molecular weight of the reaction product can be made smaller than the molecular weight of water, the speed of the flying object can be increased, and high-speed launch using a stable propellant can be easily achieved.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a launching device using a propellant according to the present invention.
[Explanation of symbols]
1 Propellant 2 Metal cylinder 3 Cylindrical insulator 4 Metal rod 5 Capacitor bank 6 Switch 7 Fuse 8 Flying object

Claims (2)

A propellant obtained by mixing prill ammonium nitrate and polyoxymethylene, wherein the polyoxymethylene is 4 mol or more per mol of prill ammonium nitrate. 2. The propellant according to claim 1, wherein the polyoxymethylene homopolymer has an average particle size in the range of 50 μm to 2000 μm.

Images