CZ12609U1 - Thermal igniter - Google Patents

Description

Thermal igniter

Technical field

The technical solution relates to the chemical composition of a thermal igniter, which can be used as an igniting sparkler for thermal welding.

BACKGROUND OF THE INVENTION

During welding, in particular welding of iron joints or repairs, it is necessary to ignite the bonding welding mixture, which is in the form of a thermal mixture which, after ignition and burn-off, forms a solid weld between the welded parts or filler at the repair site. The welding thermal composition cannot be ignited by simple means, such as a primer generating a temperature of about 900 ° C, since a substantially higher temperature, at least 1500 ° C, is required to ignite the thermal composition. The use of torches for ignition is possible, but for field welding, such as rail welding, it is inconvenient as it provides extra tools that require transport space and the need for power supply, increase load, need for on-site transport and are relatively labor intensive and compliance with safety rules.

Against this, known sparklers are known for their ability to ignite the surrounding environment or nearby objects. However, they are unsuitable as igniters for thermal welding because they only develop a normal temperature which does not allow sufficient ignition and burning of the thermal mixture. Conventional sparklers are in the form of a flammable mass on a carrier in the form of a wire, wherein the flammable mass consists, for example, of 49 to 52% barium nitrate, 10 to 12% dextrin, 4.2 to 6.2% kaolin, 25 to 52%.

27% cast iron pulp, 0.8 to 1.8% borax and 6.8 to 10.8% aluminum particles, all% by weight. The aluminum particles used in conventional sparklers are in the form of flake-shaped particles and have a bulk density of 0.15 to 0.2 g / cm ³ , a commercial aluminum powder available on the market and used for various purposes. As a result of the relatively low firing temperature of the sparklers after ignition, the carrier, i.e., generally the iron wire on which the ignitable material is deposited, remains completely and partially covered by the spent slag even after the sparkler has burned out.

The essence of the technical solution

The above-mentioned disadvantages are eliminated by the thermal igniter according to the proposed technical solution. A thermal igniter is provided in the form of an incendiary sparkler, which is based on an incendiary mass deposited on a solid support. The igniter of the igniter comprises Ba (NO ₃ ) ₂ , preferably in an amount of at least 50% by weight. and a binder, preferably in an amount of at least 10 wt. The principle of the proposed solution is that the igniter of the igniter contains Fe ₂ O ₃ in an amount of at least 15% by weight. and aluminum particles in an amount of at least 20% by weight of which at least 60% of the aluminum particles of the total amount of aluminum are spherical in shape and have a bulk density of 0.6 to 0.8 g / cm ³ .

The thermal igniter is also solved in terms of the proportions of the substances contained, which allows to safely reach the temperature above 1500 ° C necessary for igniting the thermal mixture and achieves the effect of melting the carrier when igniting the igniter. purposes. The residual burn-out of the igniter is very important because it enables the formation of a compact mass when used for welding purposes. Preferably, the combustible composition consists of 50 to 55 wt. % barium nitrate, 10 to 13 wt. % dextrin, 15 to 17 wt. % ferric oxide and 20-22 wt. of aluminum particles.

The thermal igniter in the fabric ratios of the preceding paragraph is solved in two preferred alternatives. According to the first one, all the aluminum particles contained in the igniter have a spherical shape and a bulk density of 0.6 to 0.8 g / cm ³ . It is aluminum specially modified for pyrotechnic purposes

-1 CZ 12609 Ul

According to a second, optimal alternative, the thermal igniter comprises 12 to 13 wt. % of aluminum particles having a spherical shape and a bulk density of 0.6 to 0.8 g / cm ³ and 8 to 9 wt. aluminum particles having a leaf-like shape and a bulk density of 0.15 to 0.2 g / cm ³ , wherein the barium nitrate is present in a greater amount 2 of the said range, namely 53 to 55% by weight. in the incendiary matter.

The designed thermal lighter allows for a flammable sparkler that is portable, has a relatively low weight and volume and allows easy handling. It is thus optimal for field use, such as welding rails in particular. When ignited, the temperature is considerably higher than the normal burning of lighters, matches, sparklers and other flammable objects. igniters and create a compact weld. Examples of technical solution

Example 1

An exemplary embodiment of the present invention is a thermal igniter in the form of an incendiary sparkler 15 consisting of an incendiary mass deposited on a copper wire coated with a wire.

The igniter of the igniter has the following composition:

Ba _{(NO3) 2} ............................................ 50 wt.

Al, powder pyrotechnic mark DUNKEL, grain size 0.045 mm, spherical shape and bulk density 0.6 to 0.8 g / cm ³ ...................... ... 22 wt.

Fe ₂ O3 ............................................... ............................................... 17 wt .

dextrin ................................................. ........................................... 11 wt.

Example 2

Another example is a mass-based thermal igniter consisting of:

Ba _{(NO3) 2} ............................................ ............................................. 55 wt.

Al, powder pyrotechnic mark DUNKEL, grain size 0.045 mm, spherical shape and bulk density 0.6 to 0.8 g / cm ³ ...................... % 20 wt.

Fe ₂ O ₃ .............................................. ............................................... 15 wt .

dextrin ................................................. ........................................... 10 wt.

Example 3

Another example is a mass-based thermal igniter consisting of:

Ba _{(NO3) 2} ............................................ .......................................... 55 wt.

Al, powder pyrotechnic mark DUNKEL, grain size 0.045 mm, spherical shape and bulk density 0.6 to 0.8 g / cm ³ ...................... ... 12 wt.

Al, conventional powder, 0.045 mm particle size, leaf shape and bulk density 0.15 to 0.2 g / cm ³ ................................ 8 wt.

Fe ₂ O ₃ .............................................. ............................................... 15 wt .

dextrin ................................................. 10 wt.

Example 4

Another example is a mass-based thermal igniter consisting of:

Ba _{(NO3) 2} ............................................ % 53 wt.

Al, powder pyrotechnic mark DUNKEL, grain size 0.045 mm, spherical shape and bulk density 0.6 to 0.8 g / cm ³ ...................... % 13 wt.

Al, normal powder, particle size 0.045 mm, leaf shape and bulk density 0.15 to 0.2 g / cm ³ ........................... 9% wt.

Fe ₂ O ³ .............................................. .................................................. 15 wt.

-2GB 12609 Ul dextrin ............................................. ................................................. 10 % .wt.

Example 5

Another example is a mass-based thermal igniter consisting of:

Ba _{(NO3) 2} ............................................ ................................................ 53 wt.

Al, pyrotechnic powder, eg DUNKEL, grain size 0.045 mm, spherical shape and bulk density 0.6 to 0.8 g / cm ³ ................... % 12 wt.

Al, normal powder, particle size 0.045 mm, leaf shape and bulk density 0.15 to 0.2 g / cm ³ ......................... 8.5 wt.

Fe ₂ O3 ............................................... ................................................. 15 %, 5 wt.

dextrin ................................................. ............................................ 11 wt.

All percentages are by weight. The thermal igniter of the described examples is used as follows. The igniter is ignited at the end of the ignitable mixture and is then immersed in the welding thermal mixture, ready for welding of iron objects and repairs, such as rails. When burning, the igniter gradually burns, including the carrier from the wire, so-called dripping wire. The welding mixture creates a compact weld.

Claims (4)

A heat ignitor in the form of an incendiary igniter based on an incendiary mass deposited on a solid support, wherein the incendiary mass comprises barium nitrate and a binder, characterized in that its incendiary mass contains iron oxide in an amount of at least 15 wt%. and particles 20 at least 20% by weight of which at least 60% of the aluminum particles have a spherical shape and a bulk density of 0.6 to 0.8 g / cm ³ . Thermal igniter according to claim 1, characterized in that its ignitable composition consists of 50 to 55 wt. % barium nitrate, 10 to 13 wt. % dextrins, 15 to 17 wt. % ferric oxide and 20-22 wt. of aluminum particles. 25 Thermal igniter according to claim 2, characterized in that all the aluminum particles contained are spherical in shape and have a bulk density of 0.6 to 0.8 g / cm ³ . Thermal igniter according to claim 2, characterized in that it contains 12 to 13 wt. % of aluminum particles having a spherical shape and a bulk density of 0.6 to 0.8 g / cm ³ and 8 to 9 wt. aluminum particles having a leaf-like shape and a bulk density of 0.15 to 0.2 g / cm ³ and that nitrate 30 is present in an amount of 53 to 55% by weight.