RU2458896C1 - Method of producing powders and ballistic propellants - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to rocket technology, particularly, to production of ballistic powders and propellants for rocket, artillery and mortar systems. Proposed method comprises boiling powder or propellant bulk, squeezing it at squeezer screw apparatus, bulk plasticization and pelletising at continuous rollers, drying of tablets at drum- or screw-type drier, homogenising, additional plasticisation in rotary extruder and extruding powder or propellant elements. Uniform feed of semis in extruder confuser zone ensures its uniform efflux via extrusion female die.

EFFECT: improved physical and ballistic properties.

2 tbl

Description

The present invention relates to the field of rocket technology, namely the production of gunpowder and ballistic type fuels for rocket, artillery and mortar systems.

A known screw method for the manufacture of ballistic type gunpowder, consisting of technological operations performed on special equipment developed taking into account the physicomechanical and rheological properties of the powder mass, interconnected by transport lines with the pressing of pieces of billets or long fine tubes on the screw press using bell-shaped pressing tool and the use of special design dies (L. Smirnov, "Equipment for the production of ballistic gunpowder by a screw technologist and charges from them. "M: MGAHM, 1997 p. 51-57, p. 114-120, edited by L. Zabelin).

This method has several disadvantages:

- complex design features of bell-shaped press tools;

- the presence of a large amount (50-200 kg) of energy-intensive powder mass, simultaneously under the influence of high pressure and temperature in the socket;

- the possibility of the development of the transition of combustion to detonation due to the closed volume in the screw press during the formation of high-energy material;

- obtaining a large number of defective products due to noncentricity, diversity, length, air inclusions.

A known method of producing ballistic artillery gunpowder, including mixing the components of the powder mass, water extraction from the powder mass in the squeezing press, plasticization on continuous rollers at a temperature of the outgoing water from the work roll 90-100 ° C, from a blank roll - 80-90 ° C the formation of tablets, drying the tablets in a drying drum at a temperature of injected air of 90-110 ° C to a moisture content of not more than 1.0% for 45 minutes, homogenizing and pressing the tablets into blocks in a screw press at a temperature of 80-95 ° C, pressing fuel e ments of the blocks on the hydraulic press at a temperature of the mold with water 70-85 ° C, from the table - 50-80 ° C and a pressure of 170-270 kgf / cm ² (patent RU №2254311 from 15.12.2003, IPC C06B 21/00 , 25/24), taken by the authors as a prototype.

However, the prototype has a number of serious disadvantages:

- the presence of a large number of apparatuses in which the processed energy-intensive powder semi-finished product is subjected to high-temperature shear during rolling, high pressure when pressing blocks through a bell-shaped press tool on a screw press and when pressing elements from blocks on a hydraulic press for a long time, long-term temperature exposure during heating blocks in ovens, which leads to a decrease in chemical resistance and thermal stability of the powder mass;

- each device has an individual electric drive and a heat supply system, is located in a separate room, which leads to an increase in production areas, additional transport links between buildings (belt, screw conveyors, vehicles, etc.); increased losses and low utilization of raw materials.

The task of the invention is to develop a cost-effective and technologically effective method for the manufacture of gunpowder and ballistic type fuels. In the proposed manufacturing method, high chemical uniformity, homogeneity of the powder or fuel is achieved, which leads to an improvement in the physicomechanical and ballistic properties: the spread of the values of the burning rate both inside the batch and between batches is reduced. Reducing the temperature-time and mechanical effects on the powder or fuel mass provides increased chemical resistance and thermal stability.

The technical result of the invention is a method of manufacturing gunpowder and ballistic type fuels by the extrusion method, which involves mixing the components - “cooking” the powder or fuel mass in an aqueous medium, squeezing it from water on an squeezer, plasticizing and tabletting the squeezed mass on continuous rollers, drying the tablet in drum or screw type drying apparatus, homogenization, additional plasticization of the semi-finished product in a rotary type extruder and extrusion of powder elements through single or multiple arms matrix-hand

The powder mass is cooked in a mixer in an aqueous medium at a temperature of 20-55 ° C for 6 hours. The powder mass is pressed to a residual moisture content of 6-12% in a squeezing screw machine at a coolant temperature of 30 ... 60 ° C, plasticization of the mass is carried out on corrugated continuous rollers at the temperature of the outgoing water from the work roll - 80 ... 100 ° C, idle roll - 70-90 ° C to obtain a semi-finished product in the form of a tablet, drying the tablet in a drum or screw type dryer with a coolant temperature of 90-110 ° C to power NOSTA not more than 1.0%.

The semi-finished product after the drying apparatus enters the feed hopper of the rotor-type extruder heated by a coolant with a temperature of 70-90 ° C, is captured by rotating gear rotors and fed to the half-shells with gaps decreasing in the direction of rotation of the rotors. The minimum value of 1 mm gaps reach the bottom of the rotors. Decreasing clearances, by analogy with a screw press, create feed and compression zones where the semi-finished product is compressed, compacted, homogenized and re-plasticized. At the point of contact of the outer circles of the rotors, the prefabrication is displaced from the depressions using the teeth included in them. In this case, the semi-finished product that has fallen into the space between the teeth of the rotors is displaced through the clearance in the meshing into the confuser zone of the extruder and, then, it is extruded through the single or multi-strand matrix in the form of shaped powder elements. The uniform entry of the semi-finished product into the confuser zone of the rotor-type extruder ensures its uniform outflow through the extrusion die. The elements emerging from the matrix at one speed along the receiving tray are sent to the cutting machine and cut to the required length. Thus, the number of returnable defects in geometric dimensions is sharply reduced. The total volume of shear deformations, which characterizes the degree of homogenization and plasticization of the powder semi-finished product, will depend on the ratio of the area at the entrance to the confuser zone of the extruder to the cross-sectional area of the extrudable elements. The temperature of the water heating the rotors and the extruder body is 70-90 ° C, the pressure in the molding zone of the extruder is 150-250 kgf / cm ² .

The main technological operations, equipment and processing regimes of gunpowder and ballistic type fuels according to the prototype and the claimed method are presented in table 1.

The main properties of gunpowder and ballistic type fuels manufactured by the present method are presented in table 2 in comparison with gunpowder made according to the prototype.

The data presented in table 2 indicate a higher homogeneity of the powders and fuels manufactured by the proposed method, and this significantly affects the strength characteristics, chemical stability and thermal stability. At the same time, high stability of ballistic characteristics is achieved, internal and inter-party spread of the burning rate is reduced, which generally increases the combat effectiveness of high-precision special equipment.

Thus, the proposed method of manufacturing gunpowder ballistic type allows you to:

- reduce the time of the technological cycle by reducing the number of basic operations by 1.5 times, to simplify the technological scheme;

- to provide an increase in the range of operational, physico-mechanical, physico-chemical, ballistic characteristics, chemical resistance and thermal stability;

- increase the economic efficiency of production by reducing heat and energy costs by 20-25%, labor costs by 15-25%, interfacial transportation costs by 40-50%, reducing interfacial losses of expensive raw materials and materials by 15-20%;

- to improve the safety of the process by reducing the amount of powder or fuel mass in the molding confuser part of the rotor type extruder.

Table 1 Technological operations and processing conditions Equipment and value of the processing mode Prototype The inventive method 1. Mixing components - "cooking" of the powder or fuel mass Mixer Mixer - water temperature in the mixer, ° C 15-35 20-55 - mixing time, h 6 6 2. The spin of the mass Wring press Wring press - heat carrier temperature, ° C 30-60 30-60 - moisture content,% 5-12 5-12 3. Plasticization Continuous Rollers Continuous Rollers - coolant temperature, ° C, from the work roll 90-100 80-100 - coolant temperature, ° C, from idle roll 80-90 70-90 4. Drying Dryer drum Tumble dryer or screw dryer - drying time, min 45 45-90 - humidity tablets,% no more than 1,0 no more than 1,0 - heat carrier temperature, ° C 90-110 90-110 5. Homogenizing tablets and forming blocks Screw press with bell-shaped press tool - - heat carrier temperature, ° C 80-95 - - pressing pressure, kgf / cm ² 200-400 - 6. Heating blocks Thermal cabinet - - heat carrier temperature, ° C 75-85 - - warm-up time, h 12-14 - 7. Pressing elements Hydropress Rotary extruder - heat carrier temperature, ° C 70-85 70-90 - pressing pressure, kgf / cm ² 170-270 150-250 The utilization rate of raw materials 0.70 0.95

table 2 Name of characteristic Characteristic Value prototype ballistic gunpowder ballistic gunpowder and fuel manufactured by the proposed method 1. The density of the powder, ρ, g / cm ³ ρ _cf. ± 10.0% ρ _cf. ± 4.2% 2. Permissible intra-party spread of the burning rate according to OST V 84-454-92 ± 5.0 ± 2.2 3. Permissible interparty spread of the burning rate according to OST V 84-454-92 ± 10.0 ± 5,4 4. Thermal resistance to gas evolution at T = 110 ° C for 5 hours, mm Hg no more (OST B 84-2085-82) 80 10

Claims (1)

A method of manufacturing powders and ballistic type fuels, including mixing the components in a mixer in an aqueous medium for 6 hours to obtain a powder or fuel mass, pressing the mass to a residual moisture content of 6-12% in a squeezing screw apparatus at a coolant temperature of 30 ... 60 ° C, plasticization and tabletting the mass on continuous grooved rollers, drying the tablets in a drying apparatus with a coolant temperature of 90-110 ° C to a moisture content of not more than 1.0%, characterized in that the components are mixed at a temperature of 20-55 ° C, plastic cation and tabletting of the mass is carried out at a temperature of outgoing water from a work roll of 80-100 ° C, a blank roll of 70-90 ° C, drying of the tablets is carried out in a drum or screw type dryer for 45-90 minutes to a moisture content of not more than 1, 0%, and homogenization, additional plasticization and the production of powder and fuel cells is carried out in a rotary type extruder at a temperature of 70-90 ° C and a pressure of 150-250 kgf / cm ² .