Study On The Design And Performance Of Combustion Red Phosphorus Smoke Agent

Red phosphorus has a long history as a smoking material.The smoke screen formed after burning of red phosphorus has a good obstructing and attenuation effect on visible light,laser and infrared.However,the formation of easily hygroscopic phosphorus pentoxide during the combustion of red phosphorus will block the continuous combustion of red phosphorus.In order to solve the problem of rapid and continuous red phosphorus smoke generation,oxidant and combustible are usually added to form red phosphorus smoke agent.But the addition of oxidant and combustible will increase the friction sensitivity of smoke agent,which will lead to fire accidents.Therefore,in order to solve the problem of rapid and continuous smoke emission of red phosphorus smoke agent,the formulation design and smoke performance research of low sensitivity red phosphorus smoke agent were carried out in this paper.In order to solve the contradiction between the friction sensitivity and combustion smoke performance of red phosphorus smoke agent,the selection principle of smoke agent components is determined according to the characteristics of red phosphorus and the requirements of low sensitivity,low moisture absorption and rapid smoke formation of red phosphorus smoke agent.Through the combustion performance test,barium nitrate and oxidant A were selected as the composite oxidant,magnesium powder as the combustible agent and fluororubber as the binder.Based on the orthogonal test design,combustion smoke test,friction sensitivity,mass burning rate of red phosphorus and residue quality as the evaluation basis,the mass percentage of each component was optimized and the influence law was analyzed.Using the method of increasing gas production and fluffing the residue,the performance of the lower sensitivity formula was improved.The results show that the mass burning rate of red phosphorus can be increased to 0.242 g/s by adding 5%ferrocene into the formula with friction sensitivity of 3.33%and mass burning rate of red phosphorus of0.17 g/s.Based on the determined composition and proportion of red phosphorus smoke agent,the influence of charging form of red phosphorus smoke agent on the combustion and fuming performance was studied.When the diameter of the cylindrical grain is 18 mm,the linear burning rate will decrease when the height of the grain increases to 40 mm.When the height of the grain is 30 mm,the diameter of the charge increases gradually,the linear burning rate of the grain remains unchanged,and the mass burning rate has a linear relationship with the burning area.In order to further improve the combustion and fuming performance of the grain,a central hole charge was designed.According to the application background,the 1/6 of the outer diameter of 104 mm and the inner diameter of 10 mm was designed as the shape of the grain.The test results show that this charging form can improve the linear burning rate decrease caused by the increase of the height of the grain.In order to study the obscuration effect of red phosphorus smoke agent,the combustion obscuration performance of smoke screen was tested in smoke box and application environment respectively with the aid of light intensity instrument and infrared thermal imager.The results showed that with the increase of mass concentration of red phosphorus smoke agent,the transmittance of smoke to visible light and infrared light decreased gradually.When the mass concentration reaches 1.8 g/m~3,the transmittance of smoke to infrared decreases to 0%,but the target is visible;When the mass concentration reaches 2.4 g/m~3,the target is completely obscured in the infrared thermal imager;When the mass concentration reaches 0.373 g/m~3,the transmissivity of the smoke screen to the visible light is reduced to1.25%,which is completely covered.According to the TOP value,the quality of smoke agent used to achieve certain obstructing effect in practical application environment is estimated.In the application environment,the 108 grains used in the test can burn smoothly and completely,the average smoke width of the smoke screen is more than 130 m,and the effective obstructing time is more than 130s.