RU2497787C1 - Method of making spherical powders for small arms - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of spherical powders for small arms. Proposed method comprises producing powder lacquer in reactor, its dispersion to spherical particles, dehydration, ethyl acetate distillation from powder elements, washing, sorting and drying. Note here that mother solution produced with spherical powder in reactor is drained in washing vessel. After mother solution setting, it is directed by liquid-packed pump via suction opening at washing fluid vessel for neutralisation. First washing of powder is performed in washing vessel by water at 75-80°C in turbulent flow for 40-60 min. Then, spherical powder is settles with mixer cut off for 5-10 min to remove water by liquid-packed pump and to direct it for settling fine fraction. Now, cold powder washing is performed for 30-40 min in water at up to 30°C. Thereafter, powder suspension is fed by oil pump into pressure vessel.

EFFECT: higher quality of powder washing, decreased number of washing cycles and lower labor input.

1 dwg, 1 tbl, 5 ex

Description

The invention relates to the field of production of spherical powders (TFP) for small arms.

US patents [1, 2] propose methods for producing TFP for small arms, which include grinding fine-grained pyroxylin powder in an aqueous medium, followed by dissolving in ethyl acetate, dispersing the powder varnish in the presence of emulsifiers, dehydrating the spherical particles with sodium sulfate, followed by distillation of the solvent from them . A disadvantage of the known methods is that the resulting powder does not provide stable ballistic characteristics.

The closest technical solution is the method of producing TFP for a 5.6 mm sports cartridge [3] - a prototype that includes loading the powder mass into the dispersion medium (water) in the reactor, the formation of powder elements, pouring the spent, separated ethyl acetate (EA) with of the previous operation and pure EA, preparation of powder varnish, its dispersion onto spherical particles, their dehydration with sodium sulfate and distillation of EA under vacuum, the collected EA is separated, the settled part is drained into the sewer. Spent EA is used in a subsequent cycle. The obtained TFP in the reactor is poured together with the mother liquor into a washing tank, the washed powder from the washing tank by a mass pump is fed into a pressure tank, and then for sorting, phlegmatization and drying.

The disadvantage of the method of producing TFP is that the suspension of the powder and the mother liquor after being formed in the reactor is discharged into a washing tank, where, after the deposition of the powder elements, water is decanted through a decantation drain. In this case, after decantation of the mother liquor, ~ 1/3 of the mass part of the mother liquor remains in the washing tank, that is, the mother liquor remains in the washing tank during subsequent washing operations. Gunpowder, not washed away from emulsifiers and sodium sulfate, does not provide the required ballistic characteristics. Such a system for flushing spherical powder leads to a large flow of water and high labor costs associated with additional flushing.

The aim of the invention is to improve the washing quality of spherical powder by completely removing the mother liquor and purifying the water from spherical powder, shortening washing cycles and reducing labor costs in the washing phase.

The goal is achieved in a method for producing spherical powder, including obtaining powder varnish in a reactor, dispersing it into spherical particles, dehydration, distillation of ethyl acetate from the powder elements, subsequent washing, sorting and drying by pouring the resulting SFP with the mother liquor into a washing tank and defend for 5 ... 10 minutes, after which the mother liquor with a liquid ring pump, through the installed suction hatches in the lower part of the washing tank, is sent to neutralization, for the first pouring powder into the washing tank pour 3 ... 6 mass. parts of hot water relative to the mass of gunpowder with a temperature of 75 ... 80 ° C and wash the gunpowder in a turbulent mode for 40 ... 60 minutes, then with the mixer turned off, the TFP is deposited for 5 ... 10 minutes, followed by the removal of hot water by a ring pump, which is sent for sedimentation from the fine fraction into the labyrinth sump, cold washing of the powder is carried out for 30 ... 40 minutes at a temperature of up to 30 ° C in 3 ... 6 mass. parts of water in relation to the mass of the powder, then the powder suspension of the mass pump is sent to the pressure tank.

The technological scheme developed by the authors for washing the TFP is shown in Fig. According to the well-known scheme, the powder suspension from the reactor pos. 1 was poured into a washing tank, sedimentation was carried out, and washing water was drained through a decantation valve installed above the surface of the settled powder, with 1/3 of the washing water remained in the wash tank, which required an increase in the number of washes.

According to the method developed by the authors, in the lower part of the washing tank pos.2, suction hatches are installed to remove the mother liquor and wash water from spherical powder. The mother liquor is sent to neutralization through suction hatches with a water ring pump pos.4 and water, after hot washing with the same water ring pump, is sent to a sump labyrinth to precipitate a fine fraction of gunpowder. From the labyrinth-settler, item 3, water is reused in the technological cycle. After a cold rinse, the powder suspension with a mass pump pos. 5 is fed into a pressure vessel. The technological scheme for washing the SFP developed by the authors is simple in operation, provides reliable washing of the SFP from emulsifiers and sodium sulfate, and allows 2 ... 3 times less use of water for washing powder.

For washing TFP is used in the washing tank 3 ... 6 mass. parts of hot water in relation to the mass, part of the powder with a temperature of 75 ... 80 ° C and a washing time in a turbulent mode for 40 ... 60 minutes, repeated cold washing of the TFP is also carried out in 3 ... 6 mass. parts of water in relation to 1 mass, parts of gunpowder with a temperature of up to 30 ° C for 30 ... 40 minutes. All this provides a complete washing of the powder elements from the protective colloid and sodium sulfate. A decrease in water temperature during hot washing below 75 ° C and a washing time of less than 40 minutes does not ensure complete washing of emulsifiers from the surface of powder elements, and an increase in temperature during hot washing more than 80 ° C and a time of more than 60 minutes is associated with additional labor costs.

An increase in water temperature during cold washing of more than 30 ° C and mixing time of more than 40 minutes is associated with additional labor costs, and a decrease in washing time of less than 30 minutes does not completely wash the emulsifiers from the surface of the powder elements.

Technological modes of washing the TFP and ballistic characteristics obtained by the authors of the TFP within the boundary conditions (examples 1 ... 3) and outside the boundary conditions (examples 4, 5) are given in the table.

Table Technological washing regimes and ballistic characteristics of the TFP The name of indicators Example
(Project No. 1) Etc. Number 2 Etc. Number 3 Etc. Number 4 Etc. Number 5 Sludge time in the washing tank of the powder mixture discharged from the reactor, min 5 7 10 2 10 Decantation time of the mother liquor, min 10 10 10 10 10 The amount of hot water poured, wt. parts 3 4,5 6 2 7 Flushing time, min 40 fifty 60 thirty 70 Sludge time, min 5 7.5 10 3 12 Decantation time of hot water, min 10 10 10 10 10 The amount of hot water poured, wt. parts 3 4,5 6 2 7 Flushing time, min thirty 35 40 twenty fifty The time for pumping the suspension by the mass pump into the pressure vessel, min 10 10 10 10 10 Ballistic characteristics Mass of charge, g 0.83 0.85 0.91 0.98 The average speed of a bullet in a ballistic group, m / s 558 553 559 490 The difference between the largest and smallest values of the speed of the bullets, m / s 13 16 fifteen 40 The maximum pressure of the powder gases in the ballistic group, MPa average 221 233.2 258.8 230,4 the greatest 234.1 258.9 302.0 261.8

Literature

1. US Patent No. 2843584

2. US Patent No. 3378545

3. RF patent No. 1806462 C06B 21/00

Claims (1)

A method for producing spherical powder, including obtaining powder varnish in a reactor, dispersing it onto spherical particles, dewatering, distilling ethyl acetate from the powder elements, subsequent washing, sorting and drying, characterized in that the spherical powder obtained in the reactor with the mother liquor is poured into a washing tank and sediment for 5-10 minutes, after which the mother liquor with a water ring pump through the installed suction hatches in the lower part of the washing tank is sent to neutralization, for the first washing 3 to 6 wt.h. hot water relative to gunpowder with a temperature of 75-80 ° C and wash the gunpowder in a turbulent mode for 40-60 minutes, then when the stirrer is off for 5-10 minutes, spherical gunpowder is deposited, followed by the removal of hot water by a ring pump, which sent for sedimentation from the fine fraction into the labyrinth-sump, carry out cold washing of the powder at a temperature of up to 30 ° C in 3-6 parts by weight water in relation to the mass of gunpowder for 30-40 minutes, then the powder suspension of the mass pump is sent to the pressure tank.

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