RU2123991C1 - Method of destruction of solid propellant charges - Google Patents

Abstract

FIELD: rocketry, applicable in destruction of solid propellant charges or propellant fragment with refinement of combustion products. SUBSTANCE: method consists in phlegmatization of the greatest part of the charge burning surface with the aid of water-helium composition. The charge in the enclosure is installed vertically or slantingly, the channel is filled with water-helium composition, and after gel is formed the charge is burnt down in the position determined by the construction of the stand-utilizer. Fragments of large-sized charges a burnt down in a similar way, and pieces of propellant obtained as a result of deep disintegration of defective charges are burnt down in the medium of water-helium composition. Ecologically pure and safe method of destruction of solid propellant is attained with employment of refrigerant. EFFECT: facilitated procedure. 9 cl

Description

 The invention relates to a method for eliminating charges of solid rocket fuel (TRT) by burning, mainly to methods of burning channel charges TRT directly in the bodies of rocket engines or fragments of charges and can be used for disposal of solid rocket fuel.

 Currently, there are known methods of eliminating TRT charges by blasting, cutting, burning in buildings with a nozzle and without a nozzle at stands and special sites. All these methods have fundamental shortcomings: they cause great environmental damage, require significant land allocation, high capital and operating costs.

 So, the method of burning charges in the casing without the nozzle block in the open area [1] requires significant land allocation and causes great environmental damage.

 A known method of burning bulky charges on an environmentally friendly stand [2] with cooling the combustion products with water, localizing them in gas tanks and neutralizing.

 The disadvantage of this method is the large capital costs for the construction of the stand, the high cost of its operation, high energy consumption for cooling the combustion products - at least 10 liters of water are consumed per kilogram, followed by its purification by distillation. The stand has a low throughput - one burning per week.

 A known method of eliminating the charges of TRT by the method of delayed controlled burning [3], which consists in burning the charge from the engine casing, mounted vertically without a nozzle by a flow opening upward with a channel filled with water. The relative position of the current levels of the water surface and the combustion surface of the fuel during the burning process is controlled by special sensors and is regulated by a system of automatic water supply to the charge channel. This allows 10 - 20 times to reduce the second consumption of combustion products and make the process of burning solid fuel technically and environmentally friendly.

 The disadvantage of this method, adopted as a prototype, is the need to build a special vertical stand with complex systems for controlling the combustion process and automatic water supply to the charge channel.

 An object of the invention is the creation of an environmentally friendly and safe method of eliminating TPT charges by burning, which does not require the construction of a special vertical stand with control systems and automatic control of the burning process, allowing the use of existing horizontal stands with universal technological equipment.

 The problem is solved in that an aqueous gelling composition is used as a refrigerant, in which carboxyl methyl cellulose (CMC), polyacrylamide (PAA), gelatin, agar-agar, guargam or other gelling agents individually or as a mixture can be used as a gelling agent. Apart from the gelling agent, special additives can also be introduced into the refrigerant, for example chalk, nitrate, aluminum oxide and other substances that neutralize harmful components of the combustion products (HCl, CO, etc.) or increase the yield of industrial products during the disposal of combustion products (aluminum oxide, oxychloride aluminum, generator gas, carbon dioxide, etc.). The water-gel composition is applied to the surface of the TPT by wetting by spraying, spreading or dipping. To this end, a series of experiments was conducted on laboratory samples of 20-30 mm and a length of up to 50 mm. After the formation of a gel-like film on the surface of the charge, they were ignited at the end. In all cases, the samples burned stably; no violation of the integrity of the water-gel film was observed on the samples.

 To eliminate the charge of the TRT placed in the solid-propellant solid-propellant housing, the free volume of the channel is filled with a water-gel composition, and the combustion is carried out after gel formation in an arbitrary solid-propellant rocket position.

 With this method of combustion, the second consumption of combustion products is reduced by 10 - 20 times depending on the charge design, the maximum possible explosion safety and the possibility of using high-efficiency small-sized cleaning devices (for example, jet filters) are eliminated, the need for additional water supply to the channel is eliminated, control systems are simplified.

 The development of the proposed method was carried out on charge fragments in the form of laboratory samples weighing from 10 to 50 g and full-scale charges weighing from 6 to 100 kg with a burning time of tens of seconds to 25 minutes. Burning was carried out both with a vertical and horizontal arrangement of charges and laboratory samples.

 When burning a charge from TRT weighing 50 kg and a length of 1760 mm in a fiberglass case with a channel filled with a water-gel solution (2% polyacrylamide, 7.3% calcium carbonate, 90.7% water), sustained delayed combustion was obtained for 20 minutes. The charge was burned upright.

 To test the possibility of ensuring stable stable burning of a charge with a channel filled with a water-gel solution in a horizontal position, a charge of 100 kg and a length of 2200 mm in a fiberglass case was used. Previously, 11 kg of a water-gel solution containing 7% guargam as a gelling agent was poured into the charge channel located vertically. After gel formation, the charge was moved to a horizontal position and after 3 hours (no gel leakage was observed), it was ignited using an electric spiral. The burning of the charge lasted about 25 minutes and was stable.

 In order to save water-gel composition, an inert body can be inserted into the charge channel and refrigerant can be poured into the gap between the TPT charge surface and the inert body.

 In order to check the possibility of saving the gelling agent while ensuring a stable fuel combustion process, an inert body was placed in the charge channel weighing 6 kg - a wooden rod and an aqueous-gel solution containing 0.6% gelatin as a gelling agent was poured into the gap between the rod and the fuel. The charge burning process was stable. As an inert body can also be used inserts of paper, cardboard, plastic, having low thermal conductivity of the material.

 To burn large-sized charges from CTT weighing from 10 to 50 tons, appropriate lifting vehicles, bench stands and sewage treatment plants are required. The lower the maximum weight of the burnt charge, the lower the cost of burning it. At present, the method of cutting large-sized charges into separate fragments in the form of disks weighing 3-6 tons using hydraulic monitors has been mastered. The elimination of such disks by delayed burning will require significantly lower costs (2–3 times) than burning a whole charge, since bulky stands and treatment facilities will not be required to burn them.

 In some cases, the elimination of the TRT charge by burning in the form of a monoblock or in the form of disks is impossible due to mass defects (porosity, internal cracks, non-junction), leading to unstable fuel combustion. It is proposed to disintegrate the charge into fragments in the form of pieces of arbitrary shape and size, which are then burned in an arbitrary container in an aqueous gel composition. The proposal was verified by burning a sample of small pieces of solid fuel, placed in a porcelain cup and filled with a water-gel composition. The combustion of the TRT sample was calm and stable.

 After any burning of TPT charges bonded to the body, unburned residues remain, containing harmful chemical products of the half-decomposition of the body materials, thermal insulation, protective and fixing layer, cuffs. These residues are usually buried at special sites and landfills. However, burial as a method does not guarantee the removal of substances harmful and hazardous to human health to the surface of the earth by groundwater.

 It is proposed to burn out the unburned remains of the previous incineration, placing them in the high-temperature stream of combustion products of the next liquidated charge with the catch and purification of the combustion products in treatment facilities. This method of eliminating residual TRT charges has been tested by numerous bench tests of propulsion systems using solid rocket fuel.

Literature
1. "Labor safety in industry", N 9, 1988, pages 4-52 - analogue.

 2. Express information "Engineering News", N 23, 1974, p. 9 - analogue.

 3. Patent RU 2021560 of 04.15.93, the prototype.

Claims (9)

 1. The method of eliminating the charge of solid rocket fuel (TRT), placed in the housing of a rocket engine on solid fuel (RDTT) or its fragment, which consists in burning it using a refrigerant, characterized in that a water gel composition is used as a refrigerant.  2. The method according to claim 1, characterized in that carboxymethyl cellulose, polyacrylamide, gelatin, agar-agar, guargam, individually or as a mixture, are used as gelling agents.  3. The method according to claim 1, characterized in that additives are added to the composition of the refrigerant, which neutralize the harmful components of the combustion products or increase the yield of industrial products during the processing of combustion products.  4. The method according to claim 1, characterized in that the water-gel composition is applied to the surface of the TPT by wetting by spraying, spreading or dipping.  5. The method according to claim 1, characterized in that when eliminating the charge of the TRT placed in the solid propellant rocket chamber, the free volume of the charge channel is pre-filled with a water-gel composition, and the combustion is performed after the gel is formed in an arbitrary position.  6. The method according to claim 1, characterized in that the refrigerant is poured into the gap between the surface and an inert body placed in the charge channel.  7. The method according to claim 4, characterized in that before combustion, the charge of the TRT is cut into fragments in the form of disks of a certain length and weight, and the combustion is carried out in parts.  8. The method according to claim 4, characterized in that before burning the charge of the TRT is divided into fragments in the form of pieces of arbitrary shape and size, which are placed in a container with a water-gel composition.  9. The method according to any one of claims 1 to 8, characterized in that the remains of the previous combustion are placed in the high-temperature stream of combustion products of the next liquid charge of TPT or its fragment.