GB2599086A

GB2599086A - Process

Info

Publication number: GB2599086A
Application number: GB2014533.0A
Authority: GB
Inventors: Andrew Quinton Kenneth
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-09-15
Filing date: 2020-09-15
Publication date: 2022-03-30
Also published as: GB202014533D0

Abstract

A process for conditioning an oxyhydrogen flame, suitable for welding is described. The process, apparatus and flame itself can be used in the welding of lead and/or an alloy. The oxyhydrogen (mixture of oxygen and hydrogen, HHO, Brown’s gas) is conditioned by passing the gas mixture through an organic solvent which may contain an alcohol. The gaseous mixture can be produced by the electrolysis process, so that the gas is produced on demand. The gas produced through electrolysis may have an undesirable water content and the conditioning process addresses this issue.

Description

PROCESS

TECHNICAL FIELD

[0001] The present disclosure relates to a process for conditioning an oxyhydrogen flame. The present disclosure further relates to a conditioned oxyhydrogen flame obtained by said process; the use of said conditioned oxyhydrogen flame in the welding of lead and/or an alloy thereof; and an oxyhydrogen flame welding apparatus.

BACKGROUND

[0002] Oxyhydrogen is a mixture of hydrogen (H2) and oxygen (02) gases, and is believed to have been the first gaseous mixture used for welding. Indeed, the first oxyhydrogen blowpipe was developed in the late eighteenth and early nineteenth centuries, and was used at that time to melt refractory materials such as platinum, porcelain, fire brick and corundum. Oxyhydrogen was also, at one time, used to weld lead. Such application was, however, discontinued in favour of oxyacetylene torches and arc welding due to simpler safety and training requirements, widespread availability of equipment and consumables and ease of equipment transportation. In particular, oxyacetylene welding is the predominant means by which lead and/or alloys thereof are welded in contemporary practice.

[0003] With increasing pressures on the environment, interest has, however, returned to oxyhydrogen. Under complete combustion conditions, oxyacetylene produces the greenhouse gas carbon dioxide, and under incomplete combustion conditions (i.e. insufficient oxygen) may further produce undesirable traces of soot and/or carbon monoxide.

In contrast, oxyhydrogen combusts to produce water vapour and heat. Oxyhydrogen flames are thus very clean compared to oxyacetylene flames. and their use would improve the environmental impact of welding. The practicalities of generating an oxyhydrogen flame are still, however, challenging.

[0004] Oxygen and hydrogen gas for use in oxyhydrogen torches may be provided by pressurised gas cylinders or from liquid oxygen and hydrogen storage tanks. Both are extremely cumbersome to transport and require numerous measures for safe handling during transport, storage, and when in use. Oxyhydrogen welding apparatus that rely on pressurised cylinders or storage tanks thus have a limited portability. Adequate ventilation and leak detection are also of particular importance for the storage and use of hydrogen gas.

Although hydrogen is non-toxic, it has a wide range of flammable concentrations in air and a lower ignition energy than hydrocarbon gases. Hydrogen also burns with an almost invisible flame. The storage and use of large quantities of compressed hydrogen therefore requires significant engineering controls and system design to ensure safety.

[0005] Oxyhydrogen can alternatively be produced by the electrolysis of water. However, the flame produced by the combustion of such oxyhydrogen (i.e. that obtained by the electrolysis of water) is not suitable for the welding of lead. Problems include the temperature of the flame and the moisture content therein. Excessive moisture content in the oxyhydrogen flame can, for example, cause failure of lead surfaces to bond to each other during welding, and crystallisation of the lead resulting in a weld with unsatisfactory mechanical properties.

[0006] Thus, oxyhydrogen flames remain unsuitable for many applications and it would be desirable to obtain an oxyhydrogen flame which addresses these issues and in particular, can be used in the welding of lead or alloys thereof. It would further be desirable to improve the environmental impact of the lead welding process through the use of a "clean" oxyhydrogen flame.

SUMMARY

[0007] In accordance with some embodiments described herein, there is provided a process for conditioning an oxyhydrogen flame, said process comprising: [0008] (i) providing a gaseous mixture comprising oxygen and hydrogen; [0009] (ii) conditioning the gaseous mixture from step (i) by passing said mixture through an organic solvent, wherein the organic solvent comprises at least one alcohol; and [0010] (iii) combusting the conditioned gaseous mixture from step (ii) to form an oxyhydrogen flame.

[0011] The at least one alcohol may be selected from the Ci-C6 alcohols and mixtures thereof, such as the C1-C4 alcohols and mixtures thereof. In some embodiments the at least one alcohol may be selected from methanol, ethanol, propan-1-ol, propan-2-ol, and mixtures thereof, e.g. propan-2-ol.

[0012] The organic solvent may comprise at least about 50% v/v of the at least one alcohol, such as between about 60 and 100% v/v of the at least one alcohol, or even between about and 100% v/v of the at least one alcohol.

[0013] In some embodiments the oxyhydrogen flame formed in step (iii) may have a moisture content of less than about 5 wt%, such as wherein the oxyhydrogen flame is substantially free of moisture. In some embodiments the moisture content of the oxyhydrogen flame formed in step (iii) may be less than the moisture content of an oxyhydrogen flame formed from a gaseous mixture comprising oxygen and hydrogen which has not been conditioned according to step (H).

[0014] In some embodiments the oxyhydrogen flame may have a core temperature greater than about 320°C and less than about 2700°C, such as greater than about 500°C and less than about 2500°C. In some embodiments the oxyhydrogen flame may have an inner cone with a length of about 0.2 mm to about 5.0 mm.

[0015] In some embodiments step (i) of the process described herein may comprise generating the gaseous mixture by subjecting alkaline water to electrolysis. The process may further comprise step (iv) of applying the oxyhydrogen flame to lead and/or an alloy thereof. In some embodiments the process may consist essentially of steps (i) to (iv).

[0016] In accordance with some embodiments described herein there is provided a conditioned oxyhydrogen flame obtained by the process described herein.

[0017] In accordance with some embodiments described herein there is provided the use of the conditioned oxyhydrogen flame described herein in the welding of lead and/or an alloy thereof.

[0018] In accordance with some embodiments described herein there is provided an oxyhydrogen flame welding apparatus, comprising an oxyhydrogen generator and a gas-conditioning tank in fluid communication with the oxyhydrogen generator, the gas-conditioning tank comprising an organic solvent, wherein the organic solvent is as defined herein.

[0019] These and other features, aspects, and advantages of the disclosure will be apparent from a reading of the following detailed description together with the accompanying drawings, which are briefly described below. The invention includes any combination of two, three, four, or more of the above-noted features as well as combinations of any two, three, four, or more features or elements set forth in this disclosure, regardless of whether such features or elements are expressly combined in a specific embodiment description herein.

This disclosure is intended to be read holistically such that any separable features or elements of the disclosure, in any of its various aspects and embodiments, should be viewed as intended to be combinable unless the context clearly dictates otherwise.

[0020] For ease of reference, these and further aspects of the present disclosure are now discussed under appropriate section headings. However, the teachings under each section are not necessarily limited to each particular section.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Having thus described aspects of the disclosure in the foregoing general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale. The drawings are exemplary only, and should not be construed as limiting the disclosure.

[0022] Figure 1 is a schematic of a process for conditioning an oxyhydrogen flame according to the present disclosure.

[0023] Figure 2 is a schematic of a process for conditioning an oxyhydrogen flame wherein oxyhydrogen is produced by subjecting alkaline water to electrolysis according to the present disclosure.

[0024] Figure 3 is a schematic of a process for conditioning an oxyhydrogen flame, wherein the conditioned oxyhydrogen flame is applied to lead and/or an alloy thereof according to the

present disclosure.

[0025] Figure 4 is a schematic of a process for conditioning an oxyhydrogen flame, wherein oxyhydrogen is produced by subjecting alkaline water to electrolysis, and wherein the conditioned oxyhydrogen flame is applied to lead and/or an alloy thereof according to the present disclosure.

DETAILED DESCRIPTION

[0026] In the following description, a number of specific details are presented in order to provide a thorough understanding of the embodiments of the present disclosure. It is, however, to be understood that this disclosure is not limited to these specific details. It is also to be understood that the terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting since the scope of the present disclosure will be limited only by the appended claims and equivalents thereof. It will also be apparent that specific details known to the person skilled in the art are omitted for the purposes of clarity where appropriate.

[0027] As used in this specification and the claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0028] In this specification, unless otherwise stated, the term "about" modifying the quantity of a component refers to variation in the numerical quantity that can occur, for example, through typical measuring and handling procedures used for making concentrates, mixtures or solutions in the real world; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of the materials employed, or to carry out the methods; and the like. The term "about" also encompasses amounts that differ due to different equilibrium conditions for a composition resulting from a particular initial mixture. Whether or not modified by the term "about", the claims include equivalents to the quantities.

[0029] The ranges provided herein provide exemplary amounts of each of the components. Each of these ranges may be taken alone or combined with one or more other component ranges.

[0030] As used herein, v/v means "volume-by-volume" as the basis for calculating an accompanying percentage. Unless indicated otherwise, all 12/0 values are volume-by-volume.

[0031] The present disclosure relates to a process for conditioning an oxyhydrogen flame. As used herein, an oxyhydrogen flame means a flame resulting from the combustion of hydrogen and oxygen, including the combustion of hydrogen in oxygen or air. Said process includes, for instance, a step of combusting the conditioned gaseous mixture to form an oxyhydrogen flame and this step is not limited in any respect.

[0032] As used herein, "conditioning" refers to the modification and specifically the improvement of one or more physical properties of the oxyhydrogen flame. A person skilled in the art will understand that a flame, and specifically an oxyhydrogen flame, may be characterised by various physical properties and parameters. Examples of such properties include, but are not limited to: moisture content; core temperature; length and/or width and/or depth of the visible part of the flame. These parameters and the measurement thereof is discussed in more detail below along with how the conditioning of the oxyhydrogen flame advantageously improves the suitability of the flame for application in the various uses thereof contemplated herein, including lead welding.

Step (i): Providing a gaseous mixture of oxygen and hydrogen [0033] In the present disclosure, the first step of the process requires a gaseous mixture to be provided comprising oxygen and hydrogen. In various embodiments of the present disclosure, the gaseous mixture consists essentially of oxygen and hydrogen; where "consists essentially of" means that specific further components can be present, namely those not materially affecting the essential characteristics of the compound or composition. In various embodiments of the present disclosure, the gaseous mixture consists of oxygen and hydrogen.

[0034] In various embodiments of the present disclosure, the gaseous mixture may comprise at least 25% v/v oxygen. The expression "at least' includes the end value of the range that is specified, meaning that "at least 25% v/v" includes the value 25% v/v. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 30% v/v oxygen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 35% v/v oxygen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 40% v/v oxygen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 45% v/v oxygen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 50% v/v oxygen.

[0035] In various embodiments of the present disclosure, the gaseous mixture may comprise at least 25% v/v hydrogen. The expression "at least" includes the end value of the range that is specified, meaning that "at least 25% v/v" includes the value 25% v/v. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 30% v/v hydrogen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 35% v/v hydrogen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 40% v/v hydrogen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 45% v/v hydrogen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 50% v/v hydrogen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 55% v/v hydrogen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 60% v/v hydrogen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 65% v/v hydrogen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 70% v/v hydrogen. In various embodiments of the present disclosure, the gaseous mixture may comprise at least 75% v/v hydrogen.

[0036] The ratio of hydrogen to oxygen may also be varied. For example, it may be desirable when welding to avoid an oxidizing flame; that is a flame with an excess amount of oxygen. For instance, a ratio of 2:1 hydrogen:oxygen may be used, where this ratio corresponds to the stoichiometric ratio for the combustion of hydrogen and oxygen to form water. In practice, higher ratios may also be used. For example, in various embodiments of the present disclosure, the ratio of hydrogen to oxygen may be 2:1, 3:1, 4:1, or 5:1; where these ratios are molar ratios.

[0037] In various embodiments of the present disclosure, the gaseous mixture may comprise traces of further substances that may be in a liquid (for example as an aerosol) or gaseous state, for example water vapour or an organic solvent vapour. In various embodiments, the gaseous mixture may comprise oxygen, hydrogen and water vapour. The amount and nature of the further substances present in the gaseous mixture may of course depend upon the means by which the gaseous mixture is provided.

[0038] Step (i) is not particularly limited in how the gaseous mixture is provided, and the skilled person will be aware of available processes in the art by which this may be achieved.

For example, a gaseous mixture comprising oxygen and hydrogen can be provided from compressed gas cylinders. As discussed above, these cylinders are cumbersome, difficult to transport, and require multiple safety measures to be stored and used safely. In various circumstances they may therefore not be desirable. Alternatively, a gaseous mixture comprising oxygen and hydrogen can be provided from liquid cylinders, i.e. wherein each gas is refrigerated and stored in the liquid phase. The storage of such liquefied gases may also be accompanied with onerous storage and safety requirements, and transport is very difficult for the same reasons. To address these problems, various embodiments of the present disclosure involve step (i) comprising the generation of the gaseous mixture by subjecting water, preferably alkaline water, to electrolysis.

[0039] Electrolysis processes which use water to provide a gaseous mixture of oxygen and hydrogen are known in the art and the for the sake of brevity, the specific details of said process or processes are not included herein. The skilled person will be aware of a suitable process from their common general knowledge. In various embodiments of the present disclosure an apparatus known as a 'HHO generator' or a 'Brown's gas generator' may, for example, be used. An example of such an apparatus is the model 2500EP gas generator supplied by OXYVVELD s.n.c., Sacile, Italy. With the use of such apparatus, electrolysis is able to decompose water into a stoichiometric mixture of hydrogen and oxygen (i.e. at a ratio of 2 molecules of hydrogen to 1 molecule of oxygen), and oxyhydrogen can be produced "on demand", that is to say oxyhydrogen can be produced as required, and consumed immediately by way of combustion. When not in use, no oxygen or hydrogen gas is additionally produced or stored by the electrolysis apparatus, thus avoiding the onerous safety requirements relating to the safe storage of compressed oxygen and hydrogen gases, as already discussed above.

[0040] Further, producing a flame by the combustion of oxygen and hydrogen obtained by the electrolysis of water has significant environmental benefits. For example, such flames do not require the consumption of fossil fuels such as hydrocarbon gases; instead the only consumable is water. Electricity for the electrolysis of the water can also be obtained from renewable sources such as solar, wind, hydroelectric, and tidal power. Finally, combustion of hydrogen and oxygen merely produces non-toxic water vapour, in contrast with the combustion of hydrocarbons, which produces undesirable soot and oxides of carbon.

[0041] In this regard, Figures 2 and 4 show example processes wherein the gaseous mixture is provided by the electrolysis of water and specifically alkaline water. By the term "alkaline water" is meant water with a pH value greater than 7.0. Alkaline water may be used in various embodiments because pure water is a poor conductor of electricity. In various embodiments of the present disclosure, the alkaline water is obtained by adding a base to water. In various embodiments of the present disclosure, the base comprises an inorganic base. In various embodiments of the present disclosure, the inorganic base is selected from the group consisting of: sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, and mixtures thereof. In various embodiments of the present disclosure, the inorganic base comprises sodium hydroxide.

[0042] In various embodiments of the present disclosure, the electrolysis of alkaline water comprises passing an electric current through the alkaline water. In an exemplary electrolysis apparatus, such as that depicted in Figures 2 and 4, the alkaline water may be stored temporarily or for a length of time in an electrolysis tank. The alkaline water is typically considered a consumable, in that it must be topped-up from time to time. Alkaline water being the main consumable is particularly advantageous, because water is a far more sustainable and environmentally friendly consumable than non-renewable hydrocarbon gases such as acetylene currently used in welding.

[0043] An electric current may be passed through the alkaline water by applying a potential difference between two electrodes that are submerged in the water. A person skilled in the art will understand that various compositions of electrode suitable for the electrolysis of water are available. A non-limiting example of a suitable electrode is one made of platinum. Further, the skilled person will understand that the present disclosure is not limited to a specific electrolysis apparatus, and that many will be suitable for the purposes of the process so described.

[0044] Generally, a potential difference of at least about 1.2 V is required to decompose water into oxygen and hydrogen by electrolysis. The rate of production of oxygen and hydrogen by electrolysis of water can, however, be varied by varying the potential difference applied across the water. Further, electrolysis apparatus that produce oxygen and hydrogen are available in various sizes, wherein larger apparatus are able to produce oxygen and hydrogen at a higher rate than smaller apparatus. For example, a typical electrolysis apparatus suitable for the process of the present disclosure may generate 30-40, 40-60, 60100, 80-150, 150-300, 250-500, or greater than 400 Uh of the gaseous mixture comprising oxygen and hydrogen. Higher gas flow rates of the gaseous mixture are typically required when using welding torches with larger nozzles.

Step (ii): conditioning the gaseous mixture by passing said mixture through an organic solvent [0045] The process of the present disclosure involves the use of an organic solvent. As used herein, an "organic solvent" is a carbon-based substance capable of dissolving or dispersing one or more other substances. In the process of the present disclosure, the gaseous mixture is conditioned by being passed through an organic solvent, wherein the organic solvent comprises at least one alcohol, i.e. at least one compound of formula R-OH, in which a hydroxyl group, -OH, is attached to a saturated carbon atom, wherein R is a hydrocarbyl radical.

[0046] The term "hydrocarbyl", as used herein, means the monovalent moiety obtained upon removal of a hydrogen atom from a parent hydrocarbon. Non-limiting examples of such hydrocarbyls are alkyl groups, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, and isomeric forms thereof; cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cycloocytyl, 2-methylcyclopentyl, 2,3-dimethyl-cyclobutyl, 4-methylcyclobutyl, 3-cyclopentylpropyl, and the like; cycloalkenyl groups, such as cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, and the like, and isomeric forms thereof; cycloalkadienyl groups, such as cyclopentadientyl, cyclohexadienyl, cycloheptadienyl, and the like; aryl groups, such as phenyl, tolyl, xylyl, naphthyl, biphenylyl, and the like; aralkyl groups, such as benzyl, phenethyl, phenpropyl, naphthmethyl, and the like.

[0047] In various embodiments of the present disclosure, the at least one alcohol is selected from the Cl-C6 alcohols and mixtures thereof. The C1-C6 alcohols comprise methanol, ethanol, propanol, butanol, pentanol, hexanol, and structural and stereoisomers thereof. It is well known in the art that alcohols with four or more carbon atoms exhibit chain isomerism, that is to say where the molecular formula remains the same but the connectivity of the carbon skeleton differs; for example the hydrocarbyl group R of R-OH may be branched or linear. Further, it is known that alcohols exhibit positional isomerism, that is to say alcohols with the same molecular formula may vary in respect to which carbon atom of the hydrocarbyl group the hydroxyl group is attached to. Thus, propanol, as used herein, for example, encompasses each of propan-1-ol and propan-2-ol.

[0048] In various embodiments of the present disclosure, the at least one alcohol is selected from the Crat alcohols and mixtures thereof. As discussed in the preceding paragraph, the term "C1-C4 alcohol" is understood to also include structural and stereoisomers thereof. For Example, the C1-C4 alcohols include: methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, and 2-methylpropan-2-ol. In various embodiments of the present disclosure, the at least one alcohol is selected from methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, and mixtures thereof, such as from methanol, ethanol, propan-1-ol, propan-2-ol, and mixtures thereof. In various embodiments of the present disclosure, the at least one alcohol comprises propan-1-ol, propan-2-ol, and mixtures thereof.

In various embodiments of the present disclosure the at least one alcohol comprises propan2-ol.

[0049] In various embodiments of the present disclosure, the organic solvent comprises at least about 50% v/v of the at least one alcohol. The expression "at least' includes the end value of the range that is specified, meaning that "at least 50% v/v" includes the value 50% v/v. In various embodiments of the present disclosure, the organic solvent comprises at least about 60% v/v of the at least one alcohol. In various embodiments of the present disclosure, the organic solvent comprises at least about 70% v/v of the at least one alcohol. In various embodiments of the present disclosure, the organic solvent comprises at least about 80% v/v of the at least one alcohol. In various embodiments of the present disclosure, the organic solvent comprises at least about 90% v/v of the at least one alcohol. In various embodiments of the present disclosure, the organic solvent comprises at least about 95% v/v of the at least one alcohol. In various embodiments of the present disclosure, the organic solvent comprises at least about 99% v/v of the at least one alcohol.

[0050] In various embodiments of the present disclosure, the organic solvent comprises between about 60 and 100% v/v of the at least one alcohol. In various embodiments of the present disclosure, the organic solvent comprises between about 70 and 100% v/v of the at least one alcohol. In various embodiments of the present disclosure, the organic solvent comprises between about 80 and 100% v/v of the at least one alcohol. In various embodiments of the present disclosure, the organic solvent comprises between about 90 and 100% v/v of the at least one alcohol. In various embodiments of the present disclosure, the organic solvent comprises between about 95 and 100% v/v of the at least one alcohol.

[0051] In various embodiments of the present disclosure, the organic solvent comprises at least about 99.9% of the at least one alcohol.

[0052] In various embodiments of the present disclosure, the organic solvent consists essentially of the at least one alcohol. In various embodiments of the present disclosure, the organic solvent consists of the at least one alcohol.

[0053] In various embodiments of the present disclosure, the organic solvent comprises at least about 50% v/v of at least one alcohol selected from the 01-04 alcohols and mixtures thereof. In various embodiments of the present disclosure, the organic solvent comprises at least about 90% v/v of at least one alcohol selected from the 01-04 alcohols and mixtures thereof. In various embodiments of the present disclosure, the organic solvent comprises at least about 99% v/v of at least one alcohol selected from the 01-04 alcohols and mixtures thereof It being understood that "the C1-C4 alcohols and mixtures thereof' are defined above.

[0054] In various embodiments of the present disclosure, the organic solvent comprises between about 60 and 100% v/v of at least one alcohol selected from the C1-04 alcohols and mixtures thereof. In various embodiments of the present disclosure, the organic solvent comprises between about 90 and 100% v/v of at least one alcohol selected from the 01-04 alcohols and mixtures thereof. In various embodiments of the present disclosure, the organic solvent comprises between about 95 and 100% v/v of at least one alcohol selected from the 01-04 alcohols and mixtures thereof. It being understood that "the 01-04 alcohols and mixtures thereof' are defined above.

[0055] In various embodiments of the present disclosure, the organic solvent comprises at least about 99.9% of at least one alcohol selected from the 01-04 alcohols and mixtures thereof It being understood that "the 01-04 alcohols and mixtures thereof" are defined above.

[0056] In various embodiments of the present disclosure, the organic solvent comprises at least about 50 % v/v of the at least one alcohol, wherein the at least one alcohol is propan-2-ol. In various embodiments of the present disclosure, the organic solvent comprises at least about 90 % v/v of the at least one alcohol, wherein the at least one alcohol is propan-2-ol. In various embodiments of the present disclosure, the organic solvent comprises at least about 99 °AD v/v of the at least one alcohol, wherein the at least one alcohol is propan-2-ol.

[0057] In various embodiments of the present disclosure, the organic solvent comprises between about 60 and 100% v/v of the at least one, wherein the at least one alcohol is propan-2-ol. In various embodiments of the present disclosure, the organic solvent comprises between about 90 and 100% v/v of the at least one alcohol, wherein the at least one alcohol is propan-2-ol. In various embodiments of the present disclosure, the organic solvent comprises between about 95 and 100% v/v of the at least one alcohol, wherein the at least one alcohol is propan-2-ol.

[0058] In various embodiments of the present disclosure, the organic solvent comprises at least about 99.9 % v/v of the at least one alcohol, wherein the at least one alcohol is propan2-ol.

[0059] As shown by the processes of Figures 1 to 4, the "passing through" of the gaseous mixture and organic solvent may be carried out in a gas-conditioning tank. "Passing through" means that the gaseous mixture is contacted with and during said contact enters, at least partially, the liquid phase of the organic solvent. The present disclosure is not, however, limited to such a configuration so long as the gaseous mixture contacts the organic solvent. In various embodiments of the present disclosure, including those shown in each of Figures 1 to 4, the gaseous mixture from step (i) may be bubbled through the organic solvent. For example, the gaseous mixture may flow from the source of said mixture which is in fluid communication with the gas-conditioning tank, and enter said tank by means of an inlet that is at least partially contacting (e.g. submerged in) the organic solvent. The gaseous mixture is thereby able to "pass through" the organic solvent in the form of bubbles or the like into a separate compartment, said separate compartment may be formed above the organic solvent.

[0060] The aim of passing the gaseous mixture through the organic solvent is to bring the gaseous mixture into contact with the organic solvent. In doing so, the gaseous mixture and organic solvent are able to exchange components with one another. For example, passing the gaseous mixture through the organic solvent may introduce traces of organic solvent vapour into the gaseous mixture which may affect the subsequent properties of the subsequently formed flame thereof, such as the core flame temperature. Equally, the organic solvent may absorb traces of substances present in the gaseous mixture, for example water vapour that may be present in the gaseous mixture due to ambient humidity, or due to the process whereby the gaseous mixture is provided.

[0061] In this regard and as noted above, Figures 2 and 4 show example processes in which the gaseous mixture is provided by the electrolysis of alkaline water. During the electrolysis of alkaline water, water vapour may be entrained into the gaseous mixture from the electrolysis tank comprising the alkaline water, and this may be exacerbated by heat that can arise due to non-ideal behaviour in the electrolytic process. Without wishing to be bound by any one theory, it is, however, believed that the moisture content of the gaseous mixture and the flame arising therefrom may be reduced due to absorption of the water vapour by the organic solvent. For instance, the Applicant has found that the flame obtained by combusting a gaseous mixture comprising oxygen and hydrogen that has been conditioned by being passed through an organic solvent comprising at least one alcohol has a reduced moisture content. The benefits in terms of flame moisture content are discussed further below.

Step (iii): combusting the conditioned gaseous mixture to form an oxyhydrogen flame [0062] Step (iii) of the process of the present disclosure comprises combusting the conditioned gaseous mixture from step 00 to form an oxyhydrogen flame. In the examples depicted in each of Figures 1 to 4, the conditioned gaseous mixture may be conveyed from the conditioning tank by means of a flexible, gas-tight hose or pipe. Such means will typically be in fluid (e.g. gaseous) communication with the gas-containing compartment of the gas-conditioning tank at one end. The other end will typically be in fluid (e.g. gaseous) communication with means for forming the conditioned oxyhydrogen flame, for example a welding torch. The welding torch typically comprises an orifice or nozzle at which the oxyhydrogen flame is formed. Typically, the welding torch nozzle may have a diameter of 0.3, 0.4, 0.5, 0.6, 0.8, 1.0, or 1.2 mm. As discussed above, higher gas flow rates are usually used with welding torches with larger nozzles.

[0063] The present disclosure is not limited by the manner in which the conditioned gaseous mixture is ignited. Ignition may, for example, be provided by an external source, for example a match or a lighter applied to an outlet from which the conditioned gaseous mixture may flow, such as the outlet of a welding torch. Alternatively, ignition may be provided by a source integrated into the oxyhydrogen welding apparatus, for example a piezo ignition element present in a welding torch.

[0064] The welding torch may also provide means by which the flame can be directed to the substrate to be welded, for example lead and/or an alloy thereof. The oxyhydrogen welding apparatus may also provide means to control the flow of oxyhydrogen. The oxyhydrogen welding apparatus may also provide means to prevent flash-back of the flame to the gas-conditioning tank and/or the oxyhydrogen generator. Alternatively, flash-back prevention may provided by the gas-conditioning tank.

[0065] As already discussed above, in the present disclosure the gaseous mixture is conditioned such that the resulting oxyhydrogen flame formed on combustion is also thereby conditioned. In particular, the Applicant has unexpectedly found that conditioning a flame by the process of the present disclosure enables the use of said flame in applications where a non-conditioned oxyhydrogen flame is unsatisfactory.

[0066] A conditioned oxyhydrogen flame obtained by the process of the present disclosure may be distinguished from flames of the prior art because it has a reduced moisture content. Additionally or alternatively, a conditioned oxyhydrogen flame obtained by the process of the present disclosure may be distinguished from flames of the prior art because it has a reduced core temperature. Additionally or alternatively, a conditioned oxyhydrogen flame obtained by the process of the present disclosure may be distinguished from flames of the prior art because it has an inner cone of reduced length. These features are considered in more detail below.

[0067] In various embodiments of the present disclosure, the oxyhydrogen flame may have reduced moisture content. The Applicant has found, for instance, that an oxyhydrogen flame with reduced moisture content has an improved ability to weld lead. This improvement has been found to be particular beneficial when the oxyhydrogen is provided by the electrolysis of alkaline water, as already discussed above. In various embodiments of the present disclosure, the moisture content of the oxyhydrogen flame formed in step (iii) may be less than the moisture content of an oxyhydrogen flame formed from a gaseous mixture comprising oxygen and hydrogen which has not been conditioned according to step (ii). In various embodiments of the present disclosure, the oxyhydrogen flame formed in step (iii) may have a moisture content of less than about 30 wt%. In various embodiments of the present disclosure, the oxyhydrogen flame formed in step (iii) may have a moisture content of less than about 25 wt%. In various embodiments of the present disclosure, the oxyhydrogen flame formed in step (iii) may have a moisture content of less than about 20 wt%. In various embodiments of the present disclosure, the oxyhydrogen flame formed in step (iii) may have a moisture content of less than about 15 wt%. In various embodiments of the present disclosure, the oxyhydrogen flame formed in step (iii) may have a moisture content of less than about 10 wt%. In various embodiments of the present disclosure, the oxyhydrogen flame formed in step (iii) may have a moisture content of less than about 5 wt%. In various embodiments of the present disclosure, the oxyhydrogen flame formed in step (iii) may have a moisture content of less than about 4 wt%. In various embodiments of the present disclosure, the oxyhydrogen flame formed in step (iii) may have a moisture content of less than about 3 wt%. In various embodiments of the present disclosure, the oxyhydrogen flame formed in step (iii) may have a moisture content of less than about 2 wt%.

[0068] In some embodiments of the present disclosure, the oxyhydrogen flame may be substantially free of moisture. The term "substantially free of moisture" means that the flame contains no or only trace amounts of moisture. The moisture content of the flame may, for example, be less than about 1 wt%, less than about 0.1 wt%, or less than about 0.01 wt%. The moisture content of a flame may be determined spectroscopically, using, for example, a commercially available infrared or near-infrared spectrometer.

[0069] As noted above, the reduced moisture content of the oxyhydrogen flame may be particularly desirable for the welding of certain metals such as lead and/or alloys thereof, where a dry flame is required. Thus, in various embodiments of the present disclosure, the process further comprises applying the oxyhydrogen flame to lead and/or an alloy thereof. Figures 3 and 4 show example processes of the present disclosure wherein the conditioned flame is applied to lead and/or an alloy thereof when used in welding. Thus, a conditioned oxyhydrogen flame obtained by the process of the present disclosure and the use of the conditioned oxyhydrogen flame obtained by the process of the present disclosure in the welding of lead and/or an alloy thereof is also contemplated. The application of the flame in welding will be performed according to standard practices in the art, such as by means of a suitable welding torch and techniques well known in the field of lead welding.

[0070] In various embodiments of the present disclosure, the oxyhydrogen flame formed in step (iii) may have a modified core temperature. Such a modified core temperature may be obtained in addition to, or as an alternative to a reduced moisture content. In various embodiments, the oxyhydrogen flame may have a modified core temperature and a reduced moisture content, with moisture content values as discussed above. The term 'core' in this regard refers to the tip of the inner cone of the flame formed by the combustion of the fuel gas (i.e. oxyhydrogen in the present disclosure), where the flame comprises an inner and outer cone, and where the tip of the visible cone is normally the hottest region of a flame. The inner cone is normally used for welding.

[0071] In various embodiments of the present disclosure, the oxyhydrogen flame may have a core temperature less than about 3300°C. In various embodiments of the present disclosure, the oxyhydrogen flame may have a core temperature less than about 3000°C. In various embodiments of the present disclosure, the oxyhydrogen flame may have a core temperature less than about 2700°C. In various embodiments of the present disclosure, the oxyhydrogen flame may have a core temperature less than about 2500°C. In various embodiments of the present disclosure, the oxyhydrogen flame may have a core temperature less than about 2200°C. In various embodiments of the present disclosure, the oxyhydrogen flame may have a core temperature less than about 1900°C. In various embodiments of the present disclosure, the oxyhydrogen flame may have a core temperature less than about 1600°C. In various embodiments of the present disclosure, the oxyhydrogen flame may have a core temperature less than about 1300°C. In various embodiments of the present disclosure, the oxyhydrogen flame may have a core temperature less than about 1000°C.

[0072] In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 320°C and less than about 2700°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 500°C and less than about 2700°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 800°C and less than about 2700°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 700°C and less than about 2700°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 1000°C and less than about 2700°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 1300°C and less than about 2700°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 1600°C and less than about 2700°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 1900°C and less than about 2700°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 2100°C and less than about 2700°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 2400°C and less than about 2700°C.

[0073] In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 320°C and less than about 2500°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 500°C and less than about 2500°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 800°C and less than about 2500°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 700°C and less than about 2500°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 1000°C and less than about 2500°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 1300°C and less than about 2500°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 1600°C and less than about 2500°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 1900°C and less than about 2500°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 2100°C and less than about 2500°C. In various embodiments of the present disclosure, the oxyhydrogen flame has a core temperature greater than about 2400°C and less than about 2500°C.

[0074] The core temperature of a flame may be measured spectroscopically, or by probe thermometry.

[0075] The size of an oxyhydrogen flame may also be important for certain applications thereof For example, a small focused flame may allow precise welding of smaller features, may reduce the risk of overheating the metal to be welded, and/or may reduce the risk of heat damage to surrounding areas and objects therein. In various embodiments of the present disclosure, the oxyhydrogen flamed formed in step (iii) may have an inner cone with a length less than that of a flame that has not been conditioned according to step (ii). In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 0.2 mm to about 5.0 mm. In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 1.0 mm to about 5.0 mm. In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.0 mm to about 4.0 mm. In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.5 mm to about 3.5 mm.

[0076] Flame length can be measured by means of calibrated photography.

[0077] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.0 mm to about 4.0 mm and a moisture content of less than about 5 wt%. In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.0 mm to about 4.0 mm and is substantially free of moisture.

[0078] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.5 mm to about 3.5 mm and a moisture content of less than about 5 wt%. In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.5 mm to about 3.5 mm and is substantially free of moisture.

[0079] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.0 mm to about 4.0 mm, a moisture content of less than about 5 wt%, and has a core temperature less than about 2700°C.

[0080] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.0 mm to about 4.0 mm, a moisture content of less than about 5 wt%, and has a core temperature less than about 2500°C.

[0081] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.0 mm to about 4.0 mm, is substantially free of moisture, and has a core temperature less than about 2700°C.

[0082] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.0 mm to about 4.0mm, is substantially free of moisture, and has a core temperature less than about 2500°C.

[0083] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.5 mm to about 3.5 mm, a moisture content of less than about 5 wt%, and has a core temperature less than about 2700°C.

[0084] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.5 mm to about 3.5 mm, a moisture content of less than about 5 wt%, and has a core temperature less than about 2500°C.

[0085] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.5 mm to about 3.5 mm, is substantially free of moisture, and has a core temperature less than about 2700°C.

[0086] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.5 mm to about 3.5 mm, is substantially free of moisture, and has a core temperature less than about 2500°C.

[0087] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.0 mm to about 4.0 mm, a moisture content of less than about 5 wt%, and a core temperature greater than about 1800°C and less than about 2700°C.

[0088] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.0 mm to about 4.0 mm, is substantially free of moisture, and has a core temperature greater than about 1800°C and less than about 2700°C.

[0089] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.5 mm to about 3.5 mm, a moisture content of less than about 5 wt%, and a core temperature greater than about 1800°C and less than about 2700°C.

[0090] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.5 mm to about 3.5 mm, is substantially free of moisture, and has a core temperature greater than about 1800°C and less than about 2700°C.

[0091] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.0 mm to about 4.0 mm, a moisture content of less than about 5 wt%, and a core temperature greater than about 2100°C and less than about 2500°C.

[0092] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.0 mm to about 4.0 mm, is substantially free of moisture, and has a core temperature greater than about 2100°C and less than about 2700°C.

[0093] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.5 mm to about 3.5 mm, a moisture content of less than about 5 wt%, and a core temperature greater than about 2100°C and less than about 2700°C.

[0094] In various embodiments of the present disclosure, the oxyhydrogen flame has an inner cone with a length of about 2.5 mm to about 3.5 mm, is substantially free of moisture, and has a core temperature greater than about 2100°C and less than about 2700°C.

Oxyhydrogen flame welding apparatus [0095] An aspect of the present disclosure is the provision of an oxyhydrogen flame welding apparatus comprising an oxyhydrogen generator and a gas-conditioning tank in fluid communication with the oxyhydrogen generator, the gas-conditioning tank comprising an organic solvent, wherein the organic solvent is as disclosed herein.

[0096] Figures 2 and 4 depict examples of the present disclosure wherein a gaseous mixture of oxygen and hydrogen (oxyhydrogen) is provided from the electrolysis of alkaline water by an electrolysis apparatus, which may also be referred to as an oxyhydrogen generator or any of the names listed above such as "H HO generator" as discussed above.

[0097] The oxyhydrogen generator is in fluid (e.g. gaseous) communication with a gas-conditioning tank, that is to say that the gaseous mixture comprising oxygen and hydrogen produced by the oxyhydrogen generator may be passed to the conditioning tank as shown in Figures 2 and 4. The present disclosure is not limited by the means in which oxyhydrogen is passed from the oxyhydrogen generator to the conditioning tank. For example, the oxyhydrogen may be in gaseous communication with the conditioning tank by way of a flexible or rigid pipe that may be of plastic or metal construction, for example. The oxyhydrogen may also pass through further components before or after entering the conditioning tank, and the present disclosure is not limited in this regard. For example, the apparatus may comprise one or more valves, flash-back arrestors, or other components used for the management of gas flow.

[0098] The conditioning tank, as shown in Figures 1-4, comprises an organic solvent as disclosed herein. In the process depicted by Figures 2 and 4, the gaseous mixture comprising oxygen and hydrogen is provided by the oxyhydrogen generator and then passed through the organic solvent in the conditioning tank. The conditioning tank will therefore further comprise means to allow the gaseous mixture to pass through the organic solvent.

[0099] In the processes depicted by Figures 1-4, the conditioned gaseous mixture is subsequently ignited to form a conditioned flame, as already discussed above.

[0100] The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and/or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.

Claims

CLAIMS1. A process for conditioning an oxyhydrogen flame, said process comprising: providing a gaseous mixture comprising oxygen and hydrogen; (ii) conditioning the gaseous mixture from step (i) by passing said mixture through an organic solvent, wherein the organic solvent comprises at least one alcohol; and (iii) combusting the conditioned gaseous mixture from step 00 to form an oxyhydrogen flame.
2. The process of Claim 1, wherein the at least one alcohol is selected from the Ci-C6 alcohols and mixtures thereof.
3. The process of Claim 2, wherein the at least one alcohol is selected from the C1-C4 alcohols and mixtures thereof.
4. The process of Claim 3, wherein the at least one alcohol is selected from methanol, ethanol, propan-1-ol, propan-2-ol, and mixtures thereof.
5. The process of Claim 4, wherein the at least one alcohol is propan-2-ol.
6. The process of any of Claims 1 to 5, wherein the organic solvent comprises at least about 50% v/v of the at least one alcohol.
7. The process of Claim 6, wherein the organic solvent comprises between about 60 and 100% v/v of the at least one alcohol.
8. The process of Claim 7, wherein the organic solvent comprises between about 80 and 100% v/v of the at least one alcohol.
The process of any of Claims 1 to 8, wherein the oxyhydrogen flame formed in step (iii) has a moisture content of less than about 5 wt%.
10. The process of Claim 9, wherein the oxyhydrogen flame is substantially free of moisture.
11. The process of any of Claims 1 to 10, wherein the moisture content of the oxyhydrogen flame formed in step (iii) is less than the moisture content of an oxyhydrogen flame formed from a gaseous mixture comprising oxygen and hydrogen which has not been conditioned according to step (ii).
12. The process of any of Claims 1 to 11, wherein the oxyhydrogen flame has a core temperature greater than about 320°C and less than about 2700°C.
13. The process of Claim 12, wherein the oxyhydrogen flame has a core temperature greater than about 500°C and less than about 2500°C.
14. The process of any of Claims 1 to 13, wherein the oxyhydrogen flame has an inner cone with a length of about 0.2 mm to about 5.0 mm.
15. The process of any of Claims 1 to 14, wherein step (i) comprises generating the gaseous mixture by subjecting alkaline water to electrolysis.
16. The process of any of Claims 1 to 15, wherein the process further comprises: (iv) applying the oxyhydrogen flame to lead and/or an alloy thereof.
17. The process of Claim 16, wherein the process consists essentially of steps (i) to (iv).
18. A conditioned oxyhydrogen flame obtained by the process of any of Claims 1 to 17.
19. Use of the conditioned oxyhydrogen flame of Claim 18 in the welding of lead and/or an alloy thereof.
20. An oxyhydrogen flame welding apparatus, comprising an oxyhydrogen generator and a gas-conditioning tank in fluid communication with the oxyhydrogen generator, the gas-conditioning tank comprising an organic solvent, wherein the organic solvent is as defined in any of Claims 1 to 8.