RU2095745C1 - Pyrotechnical generator of electric current - Google Patents

Abstract

FIELD: high-temperature standby sources of electric current of single action, systems of automatics. SUBSTANCE: pyrotechnical generator of electric current is composed of cathode, anode and separator manufactured with relation of their maximum dimension to thickness from 20 to 130 and containing asbestos in the capacity of binder. Anode and cathode are made of pyrotechnical compositions with excess of combustible anode and of oxidizer - cathode. Zirconium is taken as combustible in anode and cathode and separator is produced from lithium fluoride or alkali-earth metal fluoride or from their mixture. Pyrotechnical generator of electric current has miniature dimensions and is independent in use, has 5 to 10-year warranty period at storage and operation temperature of ± 50 C, is transportation and overload-resistant. It can be manufactured with the use of standard equipment adopted in pyrotechnical industry without any substantial change of technological processes. Pyrotechnical generator of electric current can be used for operation under standby conditions to actuate fire extinguishers, blocking systems, warning systems, power supply systems of onboard equipment, low-voltage repays, microcircuits, for emergency switching on and off in case of unauthorized excess of temperature conditions, etc. in rooms of various assignment as its operation does not lead to release of ecologically harmful products. EFFECT: expanded application field, increased operational reliability and ecological safety. 2 cl, 1 dwg, 4 tbl

Description

 The invention relates to devices for converting the chemical energy of exothermic compositions into electrical energy, in particular, to high-temperature standby current sources operating in standby mode and designed to automatically power on-board equipment, devices and devices (storage bridges, pyroelectric sensors, micromotors, relays, etc.) .d.) used in automation systems and objects for various purposes (including the inclusion of fire extinguishing systems, alarms, notifications Ia, lock, etc.).

 Primary reserve sources of electric current known from the patent and scientific literature using pyrotechnic charges (Bagotsky V.S. Skundin A.M. Chemical current sources M. Energoizdat. 1981, p. 304-310; Crompton T. Primary current sources. M. Mir, 1986, pp. 295, 328, etc.), are complex in design and have a long time for reaching the operating mode, since the generation of electric current in these devices becomes possible only after the pyrotechnic charge of the pyroheater (PN) is burned, what provides fusion a solid electrolyte (salt or salt mixtures) located between the anode and cathode and heating both electrodes to operating temperature. The activation time of the backup source is reduced due to the fact that the heating element (PN) is placed directly in the electrochemical element. However, the named constructive and recipe solution of the device (Kukoz F.I. et al. Thermal current sources. Rostov-on-Don, ed. University, 1989, pp. 61-63) practically excludes the possibility of creating batteries from a set of current sources, and the practical only batteries (sets of current sources) with a voltage of 9.12 V and higher are of significance.

 In addition, the presence of pyrotechnic units predetermines the need for their separate manufacture to ensure fire and explosion safety, compliance with special requirements of technological processes, which complicates the process of their manufacture. However, the use of these current sources in systems with short-term or pulsed power modes is not economically feasible.

 The closest technical solution (prototype) is a pyrotechnic electric current generator (PGET) (single-element backup current source), in which both electrodes are made of extruded pyrotechnic compositions with a ratio of the diameter and height of each electrode equal to 2.0 2.5 [1] the anode is made of pyrotechnic composition with an excess of fuel, the cathode with an excess of oxidizing agent, and the separator is made of a porous dielectric separating the anode and cathode. The cathode is made of a mixture containing lead fluoride, lithium fluoride and aluminum, and the anode is a mixture of lead, magnesium fluoride and lithium fluoride.

 The main disadvantage of the prototype is the long delay time from the moment of activation to reaching the maximum current strength due to the low burning rate of the pyrotechnic electrodes and the inertia of the porous separator, which takes a considerable time to fill with electrolyte (more than 0.5 s). In addition, the prototype is designed to operate as a single-element current source.

 The objective of the invention is the creation of PGET with increased power and speed, i.e. with a short delay time from the moment of initiation to reaching the maximum value of the current strength and from which it is possible to collect current sources with a given voltage.

 The task is achieved in that the anode is made of pyrotechnic composition with an excess of fuel, the cathode of the pyrotechnic composition with an excess of oxidizing agent, while the separator, anode and cathode contain asbestos as a binder and are made with a ratio of their maximum size to thickness from 20 to 130, with the fuel in the anode and cathode is zirconium, and the separator is made of lithium fluoride or alkaline earth metal fluoride or a mixture thereof. The proposed composition of the anode is made of a mixture of zirconium, barium chromate or copper oxide and asbestos in the following ratio of components, wt.

Zirconium 37 83
Barium chromate or copper oxide 15 51
Asbestos 2 12,
cathode of a mixture of zirconium, copper oxide and asbestos in the following ratio of components, wt.

Zirconium 3 28
Copper oxide 60 95
Asbestos 2 12
and a separator from a mixture of asbestos with lithium fluoride or alkaline earth metal fluoride or a mixture thereof in the following ratio of components wt.

Asbestos 3 20
Lithium fluoride or alkaline earth metal fluoride or a mixture thereof 80 97
however, the separator may contain up to 60% by weight of zirconium oxide.

 The main difference between the claimed device from the prototype is the presence of the size of the anode, cathode and separator to their thickness. New prescription ratios of the components of the pyrotechnic compositions of the anode, cathode, and separator make it possible to achieve a qualitative improvement in the basic characteristics of PGET.

 In the proposed device, asbestos takes an active part in current-forming processes due to the thermochemical effect of the combustion products of the anode and cathode. Together with fluorides and zirconium dioxide provides ionic conductivity between the electrodes during current generation by the claimed device, eliminates leakage of liquid products, eliminates unauthorized short circuits of electrodes and cells.

 In addition, asbestos in conjunction with the claimed composition provides the possibility of obtaining the ratio of the maximum size of the anode, cathode and separator to their thickness from 20 to 130 (the formation of thin-layer elements of any geometric shape with a very high sensitivity of the pyrotechnic electrodes to the thermal initiating pulse. All this allows to increase the power generator in the previous dimensions, to ensure their performance.When the asbestos content is less than 2%, it does not provide the strength of the electrodes and the required leak rate With the introduction of more than 12% of asbestos, the burning rate and calorific value are unacceptably reduced, which reduce the characteristics of PHET.

 Zirconium is a combustible and active material of the anode and cathode. Copper and barium chromium oxide act as an oxidizing agent, lithium, magnesium fluoride, barium, strontium, calcium or a mixture thereof during the combustion of pyrotechnic electrodes together with primary combustion products provide ionic conductivity between the condensed residues (slag) of the anode and cathode.

 When the ratio of the maximum dimensions of the anode, cathode and separator to their thickness is less than 20, the height of the elements increases, the output parameters decrease due to an increase in internal resistance. With a ratio of more than 130 PGET become non-technological, the stability of the characteristics decreases.

 The inventive anode and cathode formulations provide the possibility of forming thin-layer porous electrodes with high sensitivity to the initiating pulse, which contributes to their rapid and complete combustion and the flow of electrochemical processes between the anode and cathode. The consequence of this is speed, high electrical characteristics, the ability to create multi-element devices of minimum height. In addition, the claimed designs and formulations of the electrodes allows for their serial production on semi-automatic lines with a high-performance and safe shear casting method (vacuum deposition of a suspension of components).

 The drawing shows the proposed PGET.

 In PGET, anode 1 and cathode 3 are made in the form of thin-layer plates of pyrotechnic composition, separated by a thin separator 2 of the same shape and placed between metal down conductors: cathode down conductor 4 and anode down conductor 5.

 PGET works as follows.

 Anode 1 and cathode 3 light up simultaneously from the initiating pulse, and at the same moment the electron transfer begins on the external circuit from combustible zirconium in anode 1 through the anode collector 5 to the cathode collector 4 and the oxidizer (copper oxide) in the cathode 3. The movement of the charged particles is due to the electrochemical oxidation of spatially separated fuel (zirconium) in anode 1 and electrochemical reduction of an oxidizing agent (copper oxide) in cathode 3 and a contact of said oxidizing agent (copper oxide) in cathode 3 and a contact of said reagents through loya ion-conducting material of the separator 2.

 The ratio of the maximum dimensions and thickness of the anode, cathode and separator 20 130 with the thickness of the pyrotechnic composition ensures the speed and power of this PSET and the minimum internal resistance, which ensures miniature size (minimum height), stable and high performance.

 The proposed ПГЭТ allows to provide autonomous power supply, on-board equipment, instruments and devices (incandescent bridges, pyroenergy sensors, micromotors, relays, etc.), as well as automation systems for various purposes (fire extinguishing, alarm, warning, blocking, etc.). As part of the sensors, it can provide independent and remote activation of fire extinguishing and warning means when the specified critical temperature is reached in warehouse and industrial fire and explosive rooms.

 The ratio of the components of the anode, cathode and separator of the prototype of the claimed solution are given in table. thirteen.

 Prototypes of the proposed PGET were made using serial production components: zirconium TU 48-4-234-84, barium chromate GOST 4211-68, copper oxide GOST 16539-79, asbestos TU 21-22-3-81, lithium fluoride TU 6- -01-3529-84, barium fluoride TU 6-09-01-261-85, strontium fluoride TU 6-09-1434-77, calcium fluoride TU 6-09-02-572-79, magnesium fluoride TU 6-09 -2674-77.

 The characteristics of the components were controlled according to GOST V84-2072-83, asbestos was prepared according to an industry methodology (instruction ZRP-1171-89). Zirconium, barium chromate, copper oxide and metal fluorides in the form of powders with a particle diameter of less than 100 microns, asbestos material with fibers 0.1 to 3 mm long and 0.0010.1 mm in diameter.

 Tests of model samples of the proposed PGET and PGET prototype according to the RF patent N 2018782 were carried out by igniting the electrodes with a hot nichrome spiral or a pulse from an MB-2N electric igniter, voltage (current at a load of 4 Ohms) and the operating time were recorded using an N-115 oscilloscope at room temperature. The test results are summarized in table. 4. In the table. Figure 4 shows the most important characteristics of the proposed PGET based on the best compositions of the anode (indices 3 and 8), the cathode (index 3) and the separator (index 3 and 7) in comparison with the characteristics of the PGET prototype and the most important characteristics of the PGET. From the table. 4 it is seen that the inventive PGET is superior to PGET in the prototype in all of the above characteristics.

 A system of two or more of the claimed PGET provides the generation of an electric current in 0.05.0.01 s after the initiation pulse is applied (all electrodes are ignited, burned and generate an electric current).

 The maximum value of the EMF is achieved in a time not exceeding 0.05.0.1 s, and a current of 0.20 ± 0.05 s from the moment of the start of operation with a total process duration of at least 6.12 s.

 The manufacture of the anode, cathode, and separator for the proposed design of the PGET does not require the development of new equipment and the re-equipment of significant facilities. The components used are widely used in pyrotechnics, the formation technology is safe. During the operation of the PSET, there is no release of environmentally harmful products.

The proposed SSET ensure the achievement of a previously unknown set of characteristics of the SSET and systems based on them and reliable operation (at least 0.999 with a confidence level of 0.9). In addition, the proposed PGET has a warranty period of at least 5.10 years at a storage and operating temperature of ± 50 ^o C.

Claims (2)

 1. Pyrotechnic electric current generator, consisting of anode and cathode separated by a separator, made of pyrotechnic compositions with an excess of combustible anode and an excess of oxidizer, a cathode, characterized in that the anode, cathode and separator contain asbestos as a binder and are made with the ratio of their maximum size to thickness 20 130, the fuel anode and cathode contain zirconium, and the separator is made of lithium fluoride or alkaline earth metal fluoride or a mixture thereof.  2. The generator according to claim 1, characterized in that the anode, cathode and separator are made in the following ratio of components, wt. Anode:
zirconium 37 83
barium chromate or copper oxide 15 51
asbestos 2 12
Cathode:
zirconium 3 28
copper oxide 60 95
asbestos 2 12
Separator:
asbestos 3 20
lithium or alkaline earth metal fluoride or a mixture thereof 80 97
3. The generator according to claim 1, characterized in that the separator further comprises zirconium oxide in an amount of up to 60 wt.

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