CN112195049A

CN112195049A - Welding gas mixture without oxygen combustion supporting

Info

Publication number: CN112195049A
Application number: CN202010902064.6A
Authority: CN
Inventors: 林宇峰
Original assignee: Ningbo Duncotek New Material Co ltd
Current assignee: Ningbo Duncotek New Material Co ltd
Priority date: 2020-09-01
Filing date: 2020-09-01
Publication date: 2021-01-08

Abstract

The invention relates to a welding gas mixture without oxygen combustion supporting. The welding gas mixture provided by the invention consists of the following gases: the weight percentage content of the propylene is 30-90 percent, the weight percentage content of the dimethyl ether is 10-70 percent, the material is easy to obtain, the use is safe, the metal can be welded and cut under the condition of no oxygen combustion supporting, and the use is very convenient.

Description

Welding gas mixture without oxygen combustion supporting

Technical Field

The present invention relates to an industrial combustion gas, in particular, it is applicable to welding and cutting copper pipe.

Background

In the industrial metal welding and cutting process, acetylene gas is generally used for welding and cutting. Acetylene is also called acetylene, is a widely used industrial gas, is a colorless and extremely flammable gas at room temperature, has flame temperature of 3160 ℃ (combustion in oxygen), is mainly used as a main gas source in the field of metal cutting and welding at present in particular in the aspect of welding metal, however, acetylene has low safety, high energy consumption in production and serious pollution, 3500 and 3800 DEG electrical consumption and 1.5 tons coke of electrical consumption of one ton of calcium carbide are produced, and 3.5 tons of pollution slag and 16 tons of sewage are produced for each ton of acetylene gas, which become industrial pollution sources. Secondly, when acetylene gas is used for welding, pure oxygen must be carried as a combustion improver, and the welding is very inconvenient particularly when working aloft.

At present, the products for replacing acetylene in China are mainly propylene, propane or a mixed gas of propylene and propane, but the fuel gas taking propylene and propane as base materials still cannot reach the combustion temperature of acetylene gas, so that the proportion of oxygen needs to be increased and more oxygen is consumed in order to obtain higher flame temperature. When the welding gas is used in oxygen-deficient environments such as plateaus, the insufficient combustion flame temperature of the welding gas is reduced due to insufficient oxygen supply, and the condition of insufficient welding is easily caused, so that the development of the welding gas capable of replacing the welding gas of the propylene copper pipe can save the cost and improve the welding effect, and the welding gas is necessary to be normally used in the oxygen-deficient environments such as plateaus.

Secondly, the installation of the central air conditioner belongs to high-altitude operation, copper pipes are often used for welding, oxyacetylene or oxygen liquefied petroleum gas is still used as welding gas in the day, and heavy fuel gas and oxygen steel cylinders are inconvenient and unsafe to carry to high altitude.

In addition, MAPP gas commonly used in foreign countries is already used for welding and cutting industrial metals, especially for welding copper pipes, and the MAPP gas comprises a mixture of propyne and allene plus part of liquefied gas, wherein the former two components are very rare in yield in China, and are not practical only in laboratory industrial production, so that a novel gas mixture with wide sources and low cost needs to be found to replace MAPP gas taking diacetylene and allene as main components.

Disclosure of Invention

The invention aims to provide a gas mixture which is high in safety, stable in flame temperature, low in cost and suitable for various brazing occasions and replaces acetylene gas and MAPP gas. The gas mixture should have the characteristics of stable performance, high combustion heat ratio, high combustion temperature, safe use and convenient carrying, and is also beneficial to environmental protection.

In order to solve the technical problem, the technical scheme adopted by the invention is as follows:

the welding gas mixture without oxygen combustion supporting is prepared by mixing propylene and dimethyl ether according to a certain proportion, wherein the mass percentage of the propylene is 30-90%, and the mass percentage of the dimethyl ether is 10-70%.

The welding gas mixture without oxygen combustion supporting is prepared by mixing propylene and dimethyl ether according to a certain proportion, wherein the mass percentage of the propylene is 40-60%, and the mass percentage of the dimethyl ether is 40-60%.

The gas mixture of the invention is allowed to contain trace gas impurities, the purity of propylene is more than or equal to 99.8 percent, the purity of dimethyl ether is more than or equal to 99.8 percent, and the effective component of the sum of propylene and dimethyl ether accounts for more than or equal to 99.8 percent of the total component.

Preferably, the gas mixture is 50% of propylene and dimethyl ether by mass: 50% of the mixture.

The two raw materials are products produced in various places of China, the propylene is a byproduct of petrochemical industry (chemical byproduct level), and the raw materials are wide and stable in source and low in price. The gas mixture principle is that the oxygen atom in the molecular structure of monomethyl ether can increase the supply of oxygen atom in the combustion process and promote the increase of the combustion temperature by utilizing the characteristic that the combustion temperature of propylene is close to that of propyne. The dimethyl ether is an environment-friendly fuel which is vigorously popularized in our country, and has wide sources and low cost. The two pure products can be burnt incompletely, but the two raw materials are mixed in proportion, so that the gas in the container can be fully burnt, the heat is uniformly released, and the production cost is reduced.

By using special welding tools and packaging containers, the actual combustion temperature of the gas mixture can reach above 1300 ℃ without using pure oxygen for combustion supporting (the actual combustion temperature of common liquefied gas is 600-800 ℃).

The gas mixture has the advantages of higher safety, easy carrying, no black smoke, tempering and other phenomena in the combustion process, overcomes the defects of easy tempering, poor safety, great environmental pollution in the production process and the like of acetylene, and overcomes the defects that the combustion temperature of pure propane is not high enough, and other industrial gases are added with additives such as benzene, hydrogen peroxide and the like, so that the gas mixture has high toxicity and is harmful to the human body of a user. The gas mixture of the invention is more economical, safe and practical. The testing pressure of the gas mixture is 1.2MPa at normal temperature, the temperature of the bottle body can be reduced when the bottle is used for a long time, and the pressure can still reach 0.3MPa even under the condition that the bottle body is in dew. Due to the unique temperature characteristic, the molecular structure of the copper tube can not be damaged due to overhigh temperature in the welding process, and meanwhile, the copper solder can be effectively melted (the melting point is about 950 ℃), so that the solder can be fully melted and flowed.

In summary, other industrial welding and cutting gases must be assisted by oxygen, and the oxygen cylinders are provided during use, which increases the potential risk of use, whereas the gas mixture of the present invention is a brazing process that can be used directly for brazing without the assistance of oxygen.

The invention has the beneficial effects that:

1. propylene, methane and ethane are used as raw materials, all the raw materials are easy to obtain, and the combustion heat and the highest flame temperature are similar to those of acetylene, so that the material can replace fast ethylene or imported copper pipe welding gas with higher cost:

2. the copper pipe welding gas has good combustion performance, can be combusted under the condition of not adopting oxygen for supporting combustion, and has the flame temperature of 1300 ℃ or higher when oxygen is not used for supporting combustion, so that a heavy oxygen cylinder does not need to be carried during high-altitude operation, the safety performance is high, and the use is convenient.

3. The components used in the copper pipe welding gas have low cost, can be purchased directly on the market, and can be used after being uniformly mixed by adopting special mixing equipment.

4. When the copper pipe welding gas is combusted and the copper pipe is welded, the sound is loud and the gas potential is sufficient when the flame is sprayed, and the barrel of the welding gun cannot generate heat after the welding gas is continuously used for 1 hour.

5. The safety performance is high: the fuel gas is insensitive to vibration and has small explosion limit (3-11%); has a narrower explosion range than acetylene gas, and is safer to use

(IV) detailed description of the preferred embodiments

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto

Herein, the

Example 1

The liquefied gas is prepared by mixing two liquefied gases of propylene and dimethyl ether according to the mass ratio of 9:1, and the liquefied gas which replaces MAPP is obtained. Under the condition that pure oxygen is not needed for combustion supporting, the actual combustion temperature can reach 1396 ℃, the continuous combustion time is 150 minutes, the gun barrel of the welding gun cannot be heated after 1 hour of use, and the welding effect is good.

Combustion performance test and tool:

1) the precision of the thermometer is as follows: 1 ℃ C.

2) High precision thermometer 0.1 deg.c (below 1000 deg.c). 1 deg.C (over 1000 deg.C). The use condition is 0-50 DEG C

Cold end temperature: and (6) automatic compensation.

3) A pressure gauge: precision 5psi, measurement range: (0 to 500psi)

4) The precision of the electronic balance is 0.1 g.

5) Stopwatch, welding gun, ignition equipment.

6) Weighing empty bottle, weighing liquefied gas filled instead of MAPP, and recording related data

Example 2

The liquefied gas is prepared by mixing two liquefied gases of propylene and dimethyl ether according to the mass ratio of 8:2, and the liquefied gas which replaces MAPP is obtained. Under the condition that pure oxygen is not needed for combustion supporting, the actual combustion temperature can reach 1382 ℃, the continuous combustion time is 160 minutes, the gun barrel of the welding gun cannot be heated after 1 hour of use, and the welding effect is good.

Example 3

The liquefied gas is prepared by mixing two liquefied gases of propylene and dimethyl ether according to the mass ratio of 7:3, and the liquefied gas which replaces MAPP is obtained. Under the condition that pure oxygen is not needed for combustion supporting, the actual combustion temperature can reach 1362 ℃, the continuous combustion time is 175 minutes, the gun barrel of the welding gun cannot be heated after 1 hour of use, and the welding effect is good.

Example 4

The liquefied gas is prepared by mixing two liquefied gases of propylene and dimethyl ether according to the mass ratio of 6:4, and the liquefied gas which replaces MAPP is obtained. Under the condition that pure oxygen is not needed for combustion supporting, the actual combustion temperature can reach 1369 ℃, the continuous combustion time is 160 minutes, the gun barrel of the welding gun cannot be heated after 1 hour of use, and the welding effect is good.

Example 5

The liquefied gas is prepared by mixing two liquefied gases of propylene and dimethyl ether according to the mass ratio of 5:5, and the liquefied gas which replaces MAPP is obtained. Under the condition that pure oxygen is not needed for combustion supporting, the actual combustion temperature can reach 1404 ℃, the continuous combustion time is 160 minutes, the gun barrel of the welding gun cannot be heated after 1 hour of use, and the welding effect is good.

Example 6

The liquefied gas is prepared by mixing two liquefied gases of propylene and dimethyl ether according to the mass ratio of 4:6, and the liquefied gas which replaces MAPP is obtained. Under the condition that pure oxygen is not needed for combustion supporting, the actual combustion temperature can reach 1358 ℃, the continuous combustion time is 150 minutes, the gun barrel of the welding gun cannot be heated after 1 hour of use, and the welding effect is good.

Example 7

The liquefied gas is prepared by mixing two liquefied gases of propylene and dimethyl ether according to the mass ratio of 3:7, and the liquefied gas which replaces MAPP is obtained. Under the condition that pure oxygen is not needed for combustion supporting, the actual combustion temperature can reach 1354 ℃, the continuous combustion time is 175 minutes, the gun barrel of the welding gun cannot be heated after 1 hour of use, and the welding effect is good.

Comparing the performance of the copper pipe welding gas and other fuel gases provided by the invention, the following results are obtained:

compared with the data of the copper pipe welding gas and other fuel gases, the copper pipe welding gas provided by the invention has the advantages that the cost is low, and the flame temperature is close to that of MAPP gas, so that the copper pipe welding gas can be used instead of imported copper pipe welding gas, and the use cost is effectively reduced. Beneficial technical effects and significant progress are achieved.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims

1. A welding gas mixture without oxygen combustion supporting is a mixture formed by mixing propylene and dimethyl ether according to a certain proportion, wherein the mass percentage of the propylene in the mixture is 30-90%, and the mass percentage of the dimethyl ether in the mixture is 10-70%.

2. The gas mixture according to claim 1, wherein the propylene is present in an amount of 40 to 60% by mass and the dimethyl ether is present in an amount of 40 to 60% by mass.

3. The gas mixture according to claim 1, wherein the propylene is present in an amount of 50% by mass and the dimethyl ether is present in an amount of 50% by mass.