CN117049932B - Flameless thermosensitive wire and preparation method thereof - Google Patents

Abstract

The invention provides a flameless thermosensitive wire and a preparation method thereof, wherein the thermosensitive wire core comprises the following components in parts by mass: 70-85 parts of temperature sensing agent, 8-15 parts of oxidant, 1-5 parts of catalyst and 4-10 parts of flame arrester; wherein the catalyst is cerium oxide or manganese dioxide. The flame arrester can disperse heat generated by the combustion of the flux core, avoid heat aggregation and reduce the combustion temperature. However, the addition of flame arrestors can result in slow heat sensitive linear combustion. By adding cerium dioxide or manganese dioxide as a catalyst, the invention can accelerate the combustion of the thermosensitive wire, ensure that the thermosensitive wire meets the practical requirement of enabling the automatic fire extinguishing device to act rapidly, promote the combustion to be more complete, reduce the generation of combustible gas such as CO and the like, and ensure the flameless combustion effect of the thermosensitive wire.

Description

Flameless thermal wire and preparation method thereof

Technical Field

The invention belongs to the technical field of fire fighting and extinguishing, and particularly relates to a flameless thermal wire and a preparation method thereof.

Background technique

In recent years, with the widespread use of automatic fire extinguishing devices, thermal wires have also been widely studied as detection and activation components. In some special environments such as explosive gases, the technical requirements for automatic fire extinguishing devices have been further improved. Among them, since the thermal wire itself will produce open flames when burned, and it is outside the device and directly exposed to the protected space, the development of flameless combustion technology for thermal wires is extremely important for the application of automatic fire extinguishing devices in special environments.

The current thermal wire technology is all flame burning, and in actual use, the technology of using casing isolation to reduce the flame is widely used, but it still cannot fundamentally solve the problem of flame or sparks generated during the combustion of thermal wire. Therefore, the development of safer thermal wire technology is crucial for the promotion and use of automatic fire extinguishing devices.

CN113912465 discloses a moisture-proof and waterproof thermistor wire, which has excellent moisture-proof performance and good flame transmission stability. However, during the combustion process, the outer skin temperature of the thermistor wire is high and flames are generated, which is not conducive to the use of the thermistor wire in flame-sensitive scenes.

Summary of the invention

The present invention provides a flameless thermal wire and a preparation method thereof, which reduces the combustion temperature of the thermal wire core so that it can achieve a flameless combustion state, broadens the application scope of the thermal wire, and improves the safety of an automatic fire extinguishing device with the thermal wire when used in an explosive environment.

The technical solution of the present invention is a flameless thermal wire, characterized in that the thermal wire core comprises the following components by mass: 70-85 parts of a temperature sensitizer, 8-15 parts of an oxidant, 1-5 parts of a catalyst and 4-10 parts of a flame extinguisher; wherein the catalyst is cerium dioxide or manganese dioxide.

Furthermore, the temperature sensitive agent is nitrocellulose.

Furthermore, the oxidant is one or more of potassium chlorate, potassium perchlorate and potassium nitrate.

Furthermore, the flame retardant is one or more of clay, bentonite or diatomaceous earth.

The present invention also relates to a method for preparing the flameless thermal sensitive wire, comprising the following steps:

S1, adding a temperature sensitive agent into a solvent for mixing and dispersing to obtain a dispersion;

S2, sieving and mixing the oxidant, the catalyst and the flame retardant to obtain a powder;

S3, adding the powder to the dispersion, and stirring to obtain a mixture;

S4, extruding the mixture into a strip lead, and obtaining a thermal sensitive wire core after drying;

S5. Sleeve the sleeve onto the outside of the thermal wire core to obtain the flameless thermal wire.

Furthermore, the solvent of S1 is an ethanol solution, and the added amount thereof is 40-60% of the total weight of the thermal wire core.

Furthermore, the mass concentration of the ethanol solution is 50-60%.

Furthermore, during the drying in S4, the temperature is 45 to 55° C., and the drying time is more than 8 hours.

Furthermore, the sleeve is a polyethylene sleeve.

The present invention has the following beneficial effects:

The flame extinguisher in the present invention plays a vital role in ensuring the flameless performance of the thermal wire. The addition of the flame extinguisher can disperse the heat generated by the combustion of the core, avoid heat accumulation, and reduce the combustion temperature. However, the addition of the flame extinguisher will cause the thermal wire to burn slowly. The present invention, by adding cerium dioxide or manganese dioxide as a catalyst, can not only accelerate the combustion of the thermal wire and ensure that the thermal wire meets the practical requirements of making the automatic fire extinguishing device act quickly, but also promote more complete combustion, reduce the generation of combustible gases such as CO, and ensure the flameless combustion effect of the thermal wire.

The cerium dioxide and manganese dioxide catalysts used in the present invention have strong oxygen storage and oxygen release capabilities, can promote redox cycles, accelerate the conversion reaction of CO, reduce the generation of combustible gases such as CO, and inhibit the formation of surface flames.

Detailed ways

The embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

Example 1

The invention discloses a preparation method of a flameless thermal line. According to parts by mass, 75 parts of nitrocellulose are added to 40 parts of an ethanol solution (the mass concentration of the ethanol solution is 50%), and the mixture is stirred to obtain a dispersion. 10 parts of potassium chlorate, 5 parts of cerium dioxide and 10 parts of clay are sieved and mixed to obtain a powder, and the powder is added to the dispersion to obtain a mixture after stirring. The mixture is extruded into a strip lead, and dried at 50°C to obtain a thermal line core. A polyethylene plastic sleeve is sheathed on the outside of the thermal core to obtain a flameless thermal line.

Example 2

The invention discloses a preparation method of a flameless thermal line. According to parts by mass, 75 parts of nitrocellulose are added to 50 parts of an ethanol solution (the mass concentration of the ethanol solution is 50%), and the mixture is stirred to obtain a dispersion. 12 parts of potassium perchlorate, 5 parts of cerium dioxide and 8 parts of bentonite are sieved and mixed to obtain a powder, and the powder is added to the dispersion to obtain a mixture after stirring. The mixture is extruded into a strip lead, and dried at 50°C to obtain a thermal line core. A polyethylene plastic sleeve is sheathed on the outside of the thermal core to obtain a flameless thermal line.

Embodiment 3:

A flameless thermal line is prepared by adding 75 parts of nitrocellulose to 60 parts of ethanol solution (the mass concentration of the ethanol solution is 60%), stirring to obtain a dispersion. 15 parts of potassium nitrate, 5 parts of manganese dioxide and 5 parts of

The diatomaceous earth is sieved and mixed to obtain a powder, and then the powder is added to the dispersion and stirred to obtain a mixture. The mixture is extruded into a strip lead and dried at 50°C to obtain a thermal wire core. A polyethylene plastic sleeve is put on the outside of the thermal core to obtain a flameless thermal wire.

Embodiment 4:

The invention discloses a preparation method of a flameless thermal line. By weight, 80 parts of nitrocellulose are added to 40 parts of an ethanol solution (the mass concentration of the ethanol solution is 50%), and the mixture is stirred to obtain a dispersion. 10 parts of potassium chlorate, 5 parts of manganese dioxide and 5 parts of clay are sieved and mixed to obtain a powder, and the powder is added to the dispersion to obtain a mixture after stirring. The mixture is extruded into a strip lead, and dried at 50°C to obtain a thermal line core. A polyethylene plastic sleeve is sheathed on the outside of the thermal core to obtain a flameless thermal line.

Embodiment 5:

A preparation method of a flameless thermal line, based on Example 4, is different only in that

5-1: wherein manganese dioxide is 1 part, clay is 9 parts, and the rest is the same as in Example 4.

5-2: wherein manganese dioxide is 3 parts, clay is 7 parts, and the rest is the same as Example 4.

5-3: wherein nitrocellulose is 85 parts, potassium chlorate is 8 parts, manganese dioxide is 3 parts, clay is 4 parts, and the rest is the same as in Example 4.

Embodiment 6:

The invention discloses a preparation method of a flameless thermal line. According to parts by mass, 75 parts of nitrocellulose are added to 40 parts of an ethanol solution (the mass concentration of the ethanol solution is 50%), and the mixture is stirred to obtain a dispersion. Five parts of potassium chlorate, seven parts of potassium perchlorate, two parts of cerium dioxide, two parts of manganese dioxide, four parts of clay and five parts of bentonite are sieved and mixed to obtain a powder, and the powder is added to the dispersion to obtain a mixture after stirring. The mixture is extruded into a strip lead, and dried at 50°C to obtain a thermal line core. A polyethylene plastic sleeve is sheathed on the outside of the thermal core to obtain a flameless thermal line.

Comparative Example 1:

A thermal line is based on Example 1, except that nitrocellulose is 78 parts, potassium chlorate is 12 parts, and clay is 10 parts.

Comparative Example 2:

A thermal line is based on Example 1, except that nitrocellulose is 85 parts, potassium chlorate is 10 parts, and cerium dioxide is 5 parts.

Comparative Example 3

A thermal sensitive wire is based on Example 1, the only difference being that an equal amount of clay is replaced by magnesium carbonate.

Comparative Example 4

A thermal line is based on Example 1, except that nitrocellulose is 77.5 parts, potassium chlorate is 12 parts, clay is 10 parts, and cerium dioxide is 0.5 parts.

Comparative Example 5

A thermal sensitive wire is based on Example 1, the only difference being that cerium dioxide is replaced by ferric oxide in equal amounts.

Comparative Example 6

A thermal sensitive wire is based on Example 1, the only difference being that an equal amount of cerium dioxide is replaced by ferrocene.

The thermistor wires prepared in the above embodiments and comparative examples were placed in an electric hot air drying oven, and the ignition temperature of the thermistor wires was tested by a slow heating method. The thermistor wires were then installed as detection and starting components in an automatic fire extinguishing device for a start-up test. The test results are shown in Table 1 below.

Table 1

The samples provided by the present invention can all be ignited smoothly under the condition of 180-190°C, and the automatic fire extinguishing device can be successfully activated. Compared with the sample thermal wire without adding flame retardant, the thermal wire of the present invention does not have visible burning flames when burning, and the sleeves remain intact after burning without damage, etc., indicating that the thermal wire prepared by the present invention achieves the effect of flameless combustion and can meet the requirements of flameless activation of the automatic fire extinguishing device. In Comparative Examples 5 and 6, although the ignition temperature of the samples using ferric oxide or ferrocene as the catalyst is not significantly different from that of the samples of the present invention, the burning rate does not achieve the expected effect and is not suitable for practical application.

The above embodiments are only for illustrating the technical ideas and features of the present invention, and the contents are only preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Within the technical scope disclosed by the present invention, equivalent changes or improvements made according to the technical solution and inventive concept of the present invention should be included in the protection scope of the present invention.

Claims (7)

1. A flameless thermal wire, characterized in that the thermal wire core comprises the following components by mass: 70-85 parts of a temperature sensitive agent, 8-15 parts of an oxidant, 1-5 parts of a catalyst and 4-10 parts of a flame extinguisher; wherein the catalyst is cerium dioxide or manganese dioxide; the temperature sensitive agent is nitrocellulose; and the flame extinguisher is one or more of clay, bentonite or diatomaceous earth. 2. The flameless thermal wire according to claim 1, characterized in that the oxidant is one or more of potassium chlorate, potassium perchlorate and potassium nitrate. 3. The method for preparing the flameless thermal wire according to any one of claims 1 to 2, characterized in that it comprises the following steps: S1, adding a temperature sensitive agent into a solvent for mixing and dispersing to obtain a dispersion; S2, sieving and mixing the oxidant, the catalyst and the flame retardant to obtain a powder; S3, adding the powder to the dispersion, and stirring to obtain a mixture; S4, extruding the mixture into a strip lead, and obtaining a thermal sensitive wire core after drying; S5. Sleeve the sleeve onto the outside of the thermal wire core to obtain the flameless thermal wire. 4. The preparation method according to claim 3 is characterized in that the solvent of S1 is an ethanol solution, and the added amount thereof is 40-60% of the total weight of the thermal sensitive wire core. 5. The preparation method according to claim 4, characterized in that the mass concentration of the ethanol solution is 50-60%. 6. The preparation method according to claim 3, characterized in that: during the drying in S4, the temperature is 45-55°C and the drying time is more than 8 hours. 7. The preparation method according to claim 3, characterized in that the sleeve is a polyethylene sleeve.