Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/02—Inorganic compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/02—Inorganic compounds
  • C11D7/04—Water-soluble compounds
  • C11D7/10—Salts
  • C11D7/14—Silicates
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/14—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions
  • C23G1/16—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions using inhibitors

Definitions

• This invention relates to cleaning compositions for cleaning or removing deposits from the walls of combustion chambers, fire boxes, furnaces and the like and for protecting such walls against corrosion.
• a cleaning agent of the indicated kind is for example disclosed in Swiss Pat. No. 360,072 which suggests an aqueous alkaline solution, particularly an aqueous sodium carbonate solution for this purpose, the solution being applied to the walls on the flue gas discharge side of the structure.
• a corrosion protecting agent in the form of alkaline earth metal compounds, compounds of the rare earths or compounds of silicon, zirconium, thorium, hafnium, vanadium or silicates or aluminates is proposed which is injected into the combustion chamber space.
• compositions of the nature referred to are disclosed in German Auslegeschrift No. l 810 424 and German Offenlegungsschrift No. l 817 798. These two publications are concerned with a procedure for the cleaning of furnaces or fire boxes with a solution of a mixture which thermally decomposes under the evolution of gas.
• the mixture comprises preferably compounds which, when heated, liberate ammonia and carbon dioxide and the mixture also comprises customary anionic. amphoteric or nonionogenic tensides.
• French Pat. No. l 434 I60 teaches a corrosion preventing layer forming agent which comprises silicates, certain specified sulfates and phosphates. Still further cleaning agents for the indicated purpose are described in Austrian Pat. No. 255 628 and in German Offenlegungsschrift No. l 521 813. According to the latter teaching. the composition comprises metasilicates, chromates, nitrates and nitrites. Finally, German Offenlegungsschrift No. l 626 66l, in a manner similar to that of Swiss Pat. No. 280 844 previously referred to, is concerned with a cleaning agent which consists essentially of an aqueous solution of a mixture of water glass and magnesium oxide and which additionally may contain wetting agents.
• an alkaline cleaning composition which is in the form of an aqueous solution, or a liquid, pasty or dry concentrate and which comprises as active ingredients a. a water soluble silicate and b. at least one water soluble ammine complex of Zn,
• a composition of the indicated kind if sprayed or otherwise injected into a combustion chamber space exerts an excellent deposit removing action and protects the walls efficiently against corrosion.
• the composition may be in the form of an aqueous solution or may be a concentrate, to wit, a dry powderlike substance or a paste or slurry.
• water soluble silicate indicates that the silicate is completely or largely water soluble.
• Suitable water soluble silicates for the purposes of this invention are tha alkali metal or ammonium metasilicates, guanidine silicates or silicate mixtures, such as alkali metal or ammonium water glass. If a sodium water glass is used, it has been found that particularly advantageous results are obtained if the water glass has an Na- O:SiO ratio of 1:0.2 to 4.0.
• the other effective ingredient in the inventive composition is a water soluble ammine (ammonium) complex of Zn, Cd, Cu and Sn.
• the complex may be prepared by reaction of a compound or salt of one of the indicated metals in aqueous solution by introducing into the solution gaseous ammonia or by the addition of concentrated or diluted aqueous ammonia solution in which the ammonia is present in the form of ammo nium hydroxide.
• Suitable ammonium complexes for the purposes of the invention are zinc tetraamminehydroxide, cadmium tetraamminehydroxide, cadmium hexaamminehydroxide, copper diamminechloride and copper tetraarnminehydroxide. It has been found that the best results are obtained with ammine complexes of zinc.
• the composition comprises 540 parts by weight of water soluble silicates and l to 10 parts by weight of ingredient (b), to wit, the amine metal complex.
• the ratio is thus 540: 1 to ID.
• superior results are obtained if 10-35 parts by weight of ingredient (a) are admixed with 2 to 8 parts by weight of ingredient (b). If ingredient (a) is present in 15 to 30 parts by weight, then ingredicnt (b) should preferably be present in 3 to 6 parts by weight.
• the cleaning agent according to the invention may additionally contain alkali metal hydroxides, preferably in an amount of about 1 to 15, advantageously 2 to 8 or 3 to 5 parts by weight, in order to increase the alkalinity of the aqueous cleaning composition. Further, the presence of the alkali metal hydroxides serves the pur pose to adjust the water glass solutions to metasilicate or orthosilicate.
• wetting agent which preferably should be present in amounts of 0.2 to 5 parts by weight per 5 to 40 parts by weight of the water soluble silicate.
• wetting agents may be in the nature of nonionogenic. cation active or anion active wetting agents.
• amphoteric wetting agents well known in the art are used for this purpose. Examples for suitable wetting agents are for example alkylnaphthalinesulfonatcs.
• alkylarylsulfonates and their sodium salts such as the sodium salt of dodecylbenzenesulfonate, sulfonated fatty acid esters, C -C -,-alkylsulfates, C C alkylpolyoxyethylene alcohols.
• the cleaning agents according to the invention may additionally contain alkali metal or ammonium phosphates, chromatcs, nitrites and/or nitrates, preferably in an amount of 0.5 to l0, particularly of 2-5 parts by weight.
• inventive alkaline cleaning agents or compositions may be prepared as concentrate in solution which thus constitutes a master solution which may be diluted prior to use in order to form solutions which can be directly sprayed into the furnace structures.
• the inventive cleaning agents are also extremely stable for indefinite periods of time when stored in the form of aqueous solutions.
• they When they are sprayed onto hot walls of combustion chambers and the like, they not only dissolve the incrustations and deposits but also form a well-adhering permanent corrosion preventing layer which essentially consists of the respective metal silicate, to wit, zinc, cadmium. copper or tin silicate, in a thickness of about 2 to lOu.
• This protective layer exerts a better and more permanent corrosion protecting effect than prior art compositions intended for the same purpose.
• the inventive composition dissolves the deposits of combustion residues and thus effectively removes them therefrom so that the silicate layers can then directly form on and adhere to the cleaned wall surfaces.
• EXAMPLE 1 A cleaning and corrosion preventing agent was prepared by mixing the following ingredients in the indicated percentages, the percentage values referring to percentages by weight.
• EXAMPLE 2 A cleaning composition which also formed a film for protecting wall surfaces against corrosion was prepared by mixing the following ingredients in the same manner as in Example 1.
• the solution thus formed was used as described in Example 1 with similar results.
• the potassium water glass and the potassium hydroxide can be replaced by 12 to 15% of potassium metsilicate, resulting in essentially the same effect.
• EXAMPLE 3 A cleaning composition which also formed a film for protecting wall surfaces against corrosion was prepared by mixing the following ingredients in the same manner as in Example 1.
• EXAMPLE 4 A cleaning composition which also formed a film for protecting wall surfaces against corrosion was prepared by mixing the following ingredients in the same manner as in Example 1.
• Aqueous potassium hydroxide solution of 57% was used as described in Example I with similar results.
• EXAMPLE 5 A cleaning composition which also formed a film for protecting wall surfaces against corrosion was prepared by mixing the following ingredients in the same manner as in Example l.
• An alkaline cleaning composition suitable for removing deposits from combustion chamber and the like walls and for protecting such walls against corrosion, said composition being in the form of an aqueous solution or a liquid or dry concentrate and consisting essentially of:
• a a water soluble silicate and b. at least one water soluble ammine complex selected from the group consisting of Zn, Cd, Cu and Sn, wherein the weight ratio of ingredients (a) to (b) is between about 5 to 40:l to 10.
• ingredient (a) is selected from the group consisting of alkali metal metasilieate, ammonium metasilicate, guanidinesilicate, alkali metal water glass and ammonium water glass.
• a cleaning composition as claimed in claim 2 wherein said water glass has an Na O:SiO ratio of 4.
• a cleaning composition as claimed in claim I additionally comprising a wetting agent in an amount of about 0.2 to 5 parts by weight per 5 to 40 parts by weight of ingredient (a).
• ingredient (b) is selected from the group consisting of zinc tetraaminehydroxide, cadmium tetraaminehydroxide, cadmium hexaamminehydroxide, copperdiamminechloride, and copper tetraamminehydroxide.
• composition suitable for removing deposits from combustion chamber and the like walls and for protecting such walls against corrosion, said composition consisting essentially of as effective ingredients:
• a water soluble silicate selected from the group consisting of alkali metal metasilicate, ammonium metasilicate, guanidinesilicate, alkali metal water glass and ammonium water glass and b. an ammine complex selected from the group consisting of Zn, Cd, Cu and Sn,
• composition comprising 5 to 40 parts by weight of ingredient (a) and l to ID parts by weight of ingredient (b).
• a cleaning composition as claimed in claim 8 further comprising about 0.2 to 5 parts by weight of a wetting agent and about 0.5 to 10 parts by weight of a member selected from the group consisting of alkali metal phosphate, alkali metal chromate, alkali metal nitrate, alkali metal nitrite, ammonium phosphate, ammonium chromate, ammonium nitrate and ammonium nitrite.
• ingredient (b) is selected from the group consisting of zinc tetraamminehydroxide, cadmium tetraamminehydroxide, cadmium hexaamminehydroxidc, coppper diamminechloride and copper tetraamminehydroxide.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Life Sciences & Earth Sciences (AREA)
• Inorganic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Detergent Compositions (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)

Applications Claiming Priority (1)

Publications (1)

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ID=5850408

Family Applications (1)

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Cited By (9)

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Citations (6)

• 1972
  • 1972-07-12 DE DE2234172A patent/DE2234172C2/de not_active Expired
• 1973
  • 1973-07-05 US US376675A patent/US3910854A/en not_active Expired - Lifetime
  • 1973-07-11 AT AT611373A patent/AT323503B/de not_active IP Right Cessation

Patent Citations (6)

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