AU5119698A

AU5119698A - Method of cleaning pipelines and containers in the food industry

Info

Publication number: AU5119698A
Application number: AU51196/98A
Authority: AU
Inventors: Dietmar Rossner
Original assignee: Henkel Ecolab GmbH and Co KG
Current assignee: Ecolab GmbH and Co oHG
Priority date: 1996-10-24
Filing date: 1997-10-15
Publication date: 1998-05-15
Also published as: DE59709454D1; EP0937133A2; WO1998017776A3; EP0937133B1; DE19643552A1; WO1998017776A2

Description

Henkel-Ecolab Semrau/abm 21.10.1996 Patent Application H 2567 Cleaning of Pipes and Containers in the Food Industry This invention relates generally to the cleaning of pipes and containers in the industrial sector, for example pipes and/or containers in the food and beverage industry, in breweries, dairies etc. More particularly, the invention relates to the use of cleaning compositions known per se for 5 hard surfaces in a process which cleans the internal surfaces of pipes and/or containers. In the food industry, equipment and buildings are cleaned by two basic methods, namely: the cleaning-in-place (CIP) method and the cleaning-on-place (COP) method. Whereas the COP method 10 encompasses the cleaning of exposed surfaces, such as floors, shelves etc., by manual or machine application, working in and/or incorporation and rinsing, the CIP method is used for cleaning internal surfaces of pipes and containers. In this method, cleaning solutions and rinsing water are prepared in tanks with a capacity of 2 to 20,000 liters which are known as 15 CIP tanks. The cleaning and rinsing liquids are pumped from these tanks to the tank or pipe system to be cleaned through valves and pipelines and are applied to the inner walls thereof by static or rotating spray systems as a trickle film or by flooding. The cleaning effect results from the chemical/physical cleaning action of the cleaning solution applied, the 20 cleaning temperature, the treatment time and the mechanical cleaning effect. The cleaning liquids flow off beneath the tank or from the pipes and are returned by a second pump to the CIP tanks through a return pipe fitted H 2567 2 with corresponding valves. The prerinse water is generally discharged into the main drainage system while fresh water used as final rinse water is collected in the prerinse tank for the next prerinse. More complex cleaning processes consist of several cleaning steps and a disinfection step. The 5 individual cleaning steps and the disinfection step are separated by an intermediate rinse with fresh water. The object of the intermediate rinsing steps is to recycle the cleaning solutions and to remove the residues from the tank and pipe walls. The solutions from the intermediate rinses are also generally delivered to the prerinse tank. CIP installations for this more 10 complex process have correspondingly more CIP tanks, for example a prerinse tank, an alkaline cleaning tank, an acidic cleaning tank, a disinfectant tank and a freshwater tank. Where necessary, the cleaning tanks can be designed to be heated to enable hot cleaning to be carried out. The above-described process is known as "stacked" CIP cleaning or 15 "stack cleaning" because the solutions are "stacked" for reuse in the CIP tanks, optionally after cleaning by membrane filtration. By contrast, in the "lost" cleaning variant, the solutions are discharged into the main drainage system on completion of the cleaning step and are not "stacked". In stacked cleaning, the losses of water and cleaning compositions 20 remain within limits, a loss of 5 to 10% being expected in well-run CIP processes. These losses are based on the volume present in the feed lines from the CIP tank to the spray head on the tank to be cleaned, in the tank itself and in the return pipe, the so-called circulation volume. The losses arise through partial mixing of the individual phases (prerinse water, 25 cleaning solutions, rinsing water) in the pipes and above all in the tank and through delays in switching during the reversal of valves. Unfortunately, the relatively small losses in well-run installations for "stacked" CIP cleaning are offset by disadvantages: 30 - The soil emanating from the cleaning process is also "stacked" with H 2567 3 the cleaning solutions. Up to a certain degree, the solutions are increasingly soiled. After an empirically determined number of cleaning cycles, therefore, the cleaning tank is emptied and refilled. - In stacked cleaning, the concentration of cleaning composition in the 5 CIP tank has to be kept constant. Losses through dilution or consumption by chemical reactions during the cleaning process have to be made up. In the prior art, concentration levels in the CIP tank are monitored by conductivity measurement. This presupposes the use of cleaning compositions with a clearly pronounced conductivity or with a clear 10 dependence of their conductivity on their concentration. Accordingly, neutral cleaning compositions often cannot be used. - In the measurement of conductivity, only the basic component of the cleaning composition used (usually sodium hydroxide or, in the case of acidic cleaning compositions, a mineral acid, such as phosphoric acid, 15 sulfuric acid or nitric acid) is determined. The concentration of this component, as measured from its conductivity, is used as an indication of the overall concentration of the product. Although this is generally practicable, it does not reliably take into account the fact that individual ingredients of modern cleaning compositions with their complex structure 20 are heavily consumed to a greater or lesser extent than the basic component. In some cases, this uncertainty cannot be tolerated and certain individual components (for example hypochlorite, peroxides, etc.) have to be separately determined at considerable cost. - The disadvantages mentioned above can be obviated by using 25 higher concentrations than theoretically necessary, as is often done. In addition, they are obviated to a certain extent by the very large quantities of cleaning composition used in the CIP tanks in relation to the soil. Unfortunately, this adversely affects the economy of the process. - "Stacked" CIP cleaning involves significant outlay on stacking tanks, 30 feed pipes, discharge pipes, pumps, valves, etc.

H 2567 4 - In cases where cleaning is to be carried out at a relatively high temperature, it is necessary to heat the entire cleaning composition which cools down again in the pipes and tanks and, after circulation, has to be returned to the required operating temperature. In this way, the entire 5 system to be cleaned, including feed and discharge pipes, has to be brought to the required cleaning temperature which involves high energy consumption. In lost cleaning, some of these disadvantages are avoided. A fresh 10 uncontaminated cleaning solution with a guaranteed content of all the ingredients is always available. Cleaning compositions without significant conductivity or products containing individual components which are less stable in solution or which react strongly with soil constituents may even be used without difficulty. The equipment used is also simpler and less 15 expensive by virtue of the absence of return pipes and stacking tanks. The problem with lost cleaning lies in a higher consumption of water, cleaning compositions and - in the case of hot cleaning - heat by comparison with the stacking process. This increased consumption can only be partly compensated by small optimized cleaning volumes and concentrations of 20 cleaning composition. In addition, lost cleaning is attended by the economic disadvantage that pipes to be cleaned have to be completely rinsed through over a relatively long cleaning time (generally 15 to 30 minutes). Containers and tanks are also cleaned by prolonged spraying with a large quantity of 25 cleaning composition. Even if the consumption of cleaning composition and water is minimized by circulation (which in turn necessitates return pipes), heat losses again occur. In addition, this method of cleaning also involves longer cleaning and hence production down times because a mechanical cleaning effect can only be achieved through laminar flow in 30 the pipes and containers.

H 2567 5 In order in conventional CIP processes to achieve complete wetting of the inner surfaces to be cleaned and to enable the cleaning solution to be rinsed out, low foaming or non-foaming cleaning solutions are normally used. The reason for this is that, for example, an only half-filled tube, of 5 which the other half is wetted with foam floating on the cleaning solution, is not completely cleaned because the mechanical and chemical cleaning power of the foam does not approach that of the cleaning solution. Foaming is also undesirable in containers because rinsing out of the foam is very time-consuming and involves significant losses of time and water 10 because filling level indicators installed in the tanks only respond after the foam has been completely eliminated. The problem addressed by the present invention was to provide an improved process for cleaning pipes and containers in the food industry. This involved avoiding the disadvantages of "lost" CIP cleaning and, hence, 15 achieving the same cleaning result or a better cleaning result with lower consumption of water and cleaning composition, lower energy costs and shorter cleaning and down times. According to the invention, the solution to this problem is characterized in that a cleaning composition is applied to the internal 20 surfaces to be cleaned in the form of an aqueous solution of cleaning concentrates thickenable with water and is rinsed off with water after a contact time of 1 to 60 minutes. In the context of the invention, the term "cleaning composition" or "cleaning solution" is understood to apply to the solution diluted with water 25 to the in-use concentration while the term "cleaning concentrate" is understood to apply to the undiluted, low-viscosity solution of the ingredients. Before application to the internal surfaces, the concentrates are diluted with water to an in-use concentration of 0.2 to 10% by weight and 30 preferably 0.5 to 2% by weight, i.e. by a factor of 10 to 500 and preferably H 2567 6 by a factor of 50 to 200. Cleaning concentrates thickenable with water are known and have been widely described in the prior art for the cleaning of hard surfaces (COP cleaning) in the food industry. However, on account of their 5 adhesion properties and/or their foaming behavior, cleaners of the type in question have been used solely for COP cleaning or for cleaning open sanitary ware, such as toilet bowls or bathtubs, because disadvantages in regard to cleaning performance and/or the removability of the foam by rinsing had been expected to occur in the cleaning of closed systems. 10 According to the invention, these cleaning concentrates thickenable with water may also be used for CIP cleaning, the use of film-forming cleaning compositions, cleaning gels and rheopexic cleaning compositions being preferred. EP-B-265 979 (Akzo) describes thickening premixes for the prepa 15 ration of thickened, aqueous single-phase cleaning compositions which consist of 0.1 to 10% by weight of a surfactant, for example in the form of a tertiary amine oxide, and 0.01 to 3% by weight of an organic anionic sulfonate. These thickened aqueous cleaning compositions show thixo tropic behavior, i.e. they develop a high viscosity on exposure to low shear 20 forces. In addition, EP-A-276 501 (Akzo) describes thickened, aqueous thixotropic cleaning compositions containing a primary, secondary or tertiary amine or diamine with at least one hydrocarbon chain consisting of at least 10 carbon atoms, an organic sulfonate and a weak acid with a pK value below 2.0. Other documents concerned with thickening cleaning 25 concentrates include, for example, WO 96/21721 (Jeyes Group PLC), EP A-0 724 013 (Colgate-Palmolive) and US-PS 5,078,896 (Akzo). Thus, DE-OS 46 04 636 (Henkel KGaA) also describes thickening aqueous cleaning compositions for hard surfaces which contain a com bination of at least one tertiary amine oxide, at least one alkyl polyglycoside 30 and at least one water-soluble organic solvent selected from the group H 2567 7 consisting of monohydric or polyhydric alcohols, glycol ethers and alkanolamines. This document does not disclose the use of the cleaning compositions for cleaning internal surfaces of pipes and containers. WO 95/02664 (Jeyes Group PLC) also describes cleaning 5 compositions thickenable by adding water which contain either ether sulfates, optionally in combination with other surfactants, or cationic surfactants, optionally together with nonionic surfactants. In this case, too, the use of the cleaning compositions in question is confined to hard exposed surfaces, such as toilet bowls, walls and floors. 10 US-PS 4,842,771 (Akzo N.V.) describes cleaning solutions which reduce their viscosity on shearing (thixotropic behavior) and which contain quaternary ammonium salts or amine oxides and cumene sulfonate, xylene sulfonate, toluene sulfonate or mixtures of these sulfonates. The cleaning solutions in question are intended for use on non-horizontal hard surfaces. 15 EP-A-0 595 590 (Page, White & Farrer) discloses a chlorine-free, low-alkali cleaning concentrate which contains amine oxides, anionic surfactants, a hydrophobicized polymer, a diluent and alkalis and which forms a gel film on hard surfaces. EP-A-0 314 232 (Unilever) describes water-thickenable cleaning 20 concentrates which contain a surfactant from the group of amines, amine oxides and quaternary ammonium salts, a co-surfactant, ionizable compounds and water. These cleaning concentrates are also intended for hard surfaces. Accordingly, cleaning concentrates thickenable with water contain 25 surface-active components, including anionic surfactants, cationic surfac tants, nonionic surfactants and optionally amphoteric surfactants, diluents, acidic or alkaline components, builders and co-builders, for example polymers, and other active substances and auxiliaries. Depending on the particular application envisaged, the cleaning concentrate may contain 30 other components, for example additional alkalis, chelating agents, other H 2567 8 anionic and/or nonionic surfactants, enzymes, preservatives, sequester ants, oxidizing (bleaching) agents, dyes and/or perfumes. Suitable anionic surfactants for thickening cleaners are mainly alkyl sulfates and sulfonates, alkyl benzenesulfonates (ABS), a-sulfofatty acid 5 esters (ester sulfonates), short-chain and long-chain glycerol esters, fatty alcohol sulfates (FAS), alkyl sulfosuccinic acid (ASB) and soaps. Examples of anionic surfactants from the groups mentioned above are the commercially available products Eltesol@ SX30 (sodium xylene sulfonate, a product of Albright & Wilson), Triton@ H55 (potassium phosphate ester, a 10 product of Union Carbide), Marlinat@ DF8 (sodium sulfosuccinate, a product of HOls), Hostapur@ SAS 30X (sodium alkane sulfonate, a product of Hoechst), Hostapur@ OS (sodium olefin sulfonate, a product of Hoechst), Petronat@ S (sodium petroleum sulfonate, a product of Witco), Hamposyl@ L30 (sodium lauroyl sarcosinate, a product of Hampshire); 15 Fenopon@ T33 (sodium-N-methyl-N-oleyl taurate, a product of GAS) and Fenopon@ AC78 (sodium coconut isothionate, a product of GAS). Cationic surfactants used in thickening cleaning concentrates emanate from the group of quaternary ammonium salts, primary, secondary and tertiary amines and salts thereof and polyamines. 20 Examples of such cationic surfactants are Empigen@ BAC (alkyl dimethyl benzalkonium chloride, a product of Albright & Wilson), Armac@ 1 (tallow amine acetate amine salts, a product of Akzo), Synprolan@ 35N3 (N-alkyl propanediamine, a product of ICI) and Symprolan@ 35X10 (ethoxylated primary amine containing 10 EO, a product of ICI). 25 Nonionic surfactants used in cleaning concentrates thickening with water emanate from the group of amine oxides, glucosides and alkyl polyglucosides (APG), alkoxylated fatty alcohols and esters thereof, alkoxylated fatty acids and alkyl phenols, alkanolamides and alkoxylation products thereof, sucrose and sugar esters, fatty acid esters and alkyl 30 amines. Examples include Synperonic@ A (alcohol ethoxylates, a product H 2567 9 of ICI), Crodet@ L24 (polyoxyethylene-24-lauric acid, a product of Croda), Synperonic@ NP (nonylphenol ethoxylates, a product of ICI), Empilan@ CME (coconut monoethanolamide, a product of Albright & Wilson), Triton@ CG110 (alkyl glucosides, a product of Union Carbide), Glucam@ E10 5 (methyl glucoside containing 10 EO, a product of Amerchol), Crodesta@ SL40 (sucrose cocoate, a product of Croda), Empilan@MAA (ethoxylated coconut monoethanolamide, a product of Albright & Wilson), Ethomeen@ C12 (ethoxylated coconut amine, a product of Akzo) and Tegosoft@ 16B (cetyl isooctanoate, a product of Goldschmidt). 10 Amphoteric surfactants optionally used, mostly only in combination with anionic surfactants, are selected from the group of alkyl betaines, alkyl aminopropionates, alkyl iminodipropionates, alkyl glycinates, carboxygly cinates, alkyl imidazolines, sulfobetaines, alkyl polyaminocarboxylates and polyamphocarboxyglycinates. Examples of surfactants of this type are 15 Tegobetain@ A4080 (alkyl dimethyl betaine, a product of Goldschmidt), Ampholak@ XCU (coconut amphoglycolate, a product of Bero Nobel), Amphotensid CT@ (alkyl imidazoline-based amphoteric surfactant, a product of Zschimmer and Schwarz), Ampholak@ XCO30 (coconut ampho carboxyglycinate, a product of Bero Nobel) and Sandobet@ SC (coconut 20 amide sulfobetaine, a product of Sandoz). Suitable diluents are, generally, monohydric or polyhydric alcohols, alkanolamines or glycol ethers providing they are miscible with water in the concentration range mentioned above. The solubilizer(s) is/are preferably selected from ethanol, n- or i-propanol, butanols, glycol, propanediol or 25 butanediol, glycerol, diglycol, propyl or butyl diglycol, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, propylene glycol methyl, ethyl or propyl ether, dipropylene glycol methyl or ethyl ether, methoxy, ethoxy or butoxytriglycol, 1 30 butoxyethoxy-2-propanol, 3-methyl-3-methoxybutanol, propylene glycol-t- H 2567 10 butyl ether and mono-, di- and triethanolamine and mixtures of these solvents. Known builders suitable for use in water-thickenable cleaning concentrates are monomeric or oligomeric phosphates such as, for 5 example, monophosphates, pyrophosphates, triphosphates and cyclic or polymeric metaphosphates. Other groups of inorganic builders include carbonates, hydrogen carbonates, borates and silicates, preferably those with a molar SiO 2 : M 2 0 (M = alkali metal) ratio of 0.5 to about 4:1 and, more particularly, about 1.0 to about 2.4:1. Organic builders may be 10 selected with advantage from the polymers and copolymers of acrylic acid, hydroxyacrylic acid, maleic acid and allyl alcohol. Poly(tetramethylene-1,2 dicarboxylates) and poly(4-methoxytetramethylene-1,2-dicarboxylates) may also be used. The inorganic and organic builders mentioned are used in the form of their water-soluble salts, especially their sodium or potassium 15 salts. Besides alkali metal hydroxides, suitable additional alkalis are, for example, sodium or potassium carbonate and sodium or potassium silicates. Suitable chelating agents are, for example, the alkali metal salts of ethylenediamine tetraacetic acid (EDTA) or nitrilotriacetic acid (NTA) and 20 alkali metal salts of anionic polyelectrolytes such as polyacrylates, polymaleates and polysulfonates. Low molecular weight hydroxycarboxylic acids, such as citric acid, tartaric acid, malic acid or gluconic acid, are also suitable. Other suitable chelating agents may be selected from organo phosphonates such as, for example, 1-hydroxyethane-1,1-diphosphonic 25 acid (HEDP), aminotri(methylenephosphonic acid) (ATMP), diethylene triamine penta(methylenephosphonic acid) and 2-phosphonobutane-1,2,4 tricarboxylic acid (PBS-AM). Oxidizing agents may also be added to the thickenable cleaning concentrates to enable oxidatively bleachable soil to be better removed 30 and/or the surfaces to be cleaned to be simultaneously freed from germs.

H 2567 11 However, the oxidizing agent is preferably not used in the cleaning concentrate, but instead is introduced through the water used for dilution which may contain H 2 0 2 for example. Now, the process according to the invention has the advantage over 5 conventional "lost" CIP processes that pipes and containers do not have to be permanently rinsed, but may be subjected to a "pulsating" cleaning process made up of wetting and a contact time. In addition, the cleaning composition adhering to or flowing slowly down the inner walls sets up vertical flows in the pipes which improve the cleaning result. In containers, 10 the film or foam of cleaning composition drains more slowly from the surface than does the solution in the conventional CIP process, so that different shear forces act on the soiled wall during the wetting phase and the contact time which also improves the cleaning result. Rheopexic cleaning compositions, i.e. cleaning compositions which 15 undergo an increase in viscosity on exposure to shear forces, are used with particular advantage in the process according to the invention. The advantages of the process according to the invention lie in the fact that the application of the rheopexic cleaning solution leads to a stable, slowly liquefying foam or film through the action of shear forces during application. 20 On the one hand, this increases the contact time on the surfaces to be cleaned by comparison with a large-cell foam; on the other hand, a mechanical cleaning effect additionally occurs during drainage - something which known film-forming cleaners do not have. A fine-cell foam which does not collapse as quickly as conventional relatively large-cell foams is 25 formed under the effect of the high viscosity which increases further under the effect of the shear forces during the mechanical application of the thickened aqueous solution. By virtue of the slow drainage of the foam from the surface, soiled areas are wetted with fresh cleaning solution flowing down, the high cleaning power of the fresh cleaning solution acting 30 on the soil in addition to the mechanical action. After a contact time of 1 to H 2567 12 60 minutes and preferably 5 to 30 minutes, depending on the concentration of the thickened aqueous solution, the cleaned surface can be rinsed. The cleaning solution can be rinsed off with cold water, the extremely fine-cell foam readily draining with the rinsing water. Although the surfaces can be 5 rinsed with hot water, as they have to be in known processes, this is not necessary because the cleaning solution can be completely removed without difficulty using only a little cold water. The combination of residence time on the surface and mechanical action on the soil means there is no need whatever for the surfaces to be precleaned. 10 Basically, any known gel-forming or film-forming and rheopexic cleaning compositions for hard surfaces in the food industry may be used in the process according to the invention. Depending on the application envisaged, the physical properties of the cleaning composition should be selected taking the required cleaning temperature into account. Thus, in 15 dairies for example, cleaning temperatures of 50 to 70*C are preferred whereas, in breweries, cleaning is carried out at 0 to 100C and, more particularly, at the temperature of the fermentation cellar (5*C). In the beverage industry, cleaning temperatures of 10 to 900C are generally preferred, temperatures of 10 to 700C being particularly preferred. 20 Besides the clear reduction in the use of aqueous cleaning solutions and the resulting saving of energy in the case of hot cleaning, the use of the cleaning compositions known per se in accordance with the invention affords another advantage: despite gelation or foaming in the pipes and on the internal walls of the containers, the compositions can be completely 25 rinsed out from the systems to be cleaned simply by brief rinsing with reduced water consumption. It can be of advantage in this regard to alter the direction of flow of the rinsing water during cleaning although this is not necessary, for example in the absence of the appropriate equipment. In this way, lost CIP cleaning can be carried out with a lower 30 consumption of cleaning solution, rinsing water, heat and cleaning time, H 2567 13 which greatly improves the economy of the process. The exemplary compositions listed below illustrate the various possibilities for preparing concentrates for use in the process according to the invention. The viscosity values as a function of the dilution factor are 5 also shown. Table 1 contains a selection of formulations of rheopexic cleaning concentrates thickening with water. Table 2 shows the viscosities of the concentrates in their original composition and after dilution with water by a factor of 5, a factor of 10 and a factor of 20, i.e. as 20%, 10% and 5% 10 aqueous preparations. The viscosity measurements were carried out at a sample temperature of 200C with a Brookfield digital viscosimeter, Model LVTDV-ll, using spindle No. 1 (LV Series Code No. 61) rotating at 30 r.p.m., the values being read off after a measuring time of 10 seconds. 15 Table 1 (Compositions in % by weight) Ingredient B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 Triton BG 10 0.5 1.0 3.0 5.0 - 1.0 2.5 5.0 5.0 5.0 AG 6202 - - - - 1.0 - - - - 20 Edenor TiO5 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Ethanol 10.0 10.0 10.0 10.0 10.0 15.0 10.0 5.0 5.0 5.0 NaOH 50% 20.0 20.0 20.0 20.0 20.0 20.0 20.0 10.0 10.0 10.0 NaXS 40% - - - - - - - - 10 NaTS 40% - - - - - - - - - 10 25 Water 66.5 66.0 64.0 62.0 66.0 61.0 64.5 78.0 67.0 67.0 Triton BG 10: alkyl polyglycoside (70%), trademark of Union Carbide AG 6202: 2-ethylhexyl glycoside (650/), trademark of Akzo Edenor TiO5 C1618 fatty acid mixture, trademark of Henkel KGaA 30 NaXS: sodium xylene sulfonate H 2567 14 NaTS: sodium toluene sulfonate Table 2 Dynamic Brookfield viscosity in mPas 5 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 Concentrate 10 11 8 6 10 6.8 7.2 9 3.6 3.8 20% in water 30 78 70 13 60 401 150 10 10 12 10% in water 10 35 30 65 25 10 70 26 24 21 10 5% in water 5 5 5 20 5 5 5 32 8 9 Table 3 contains a selection of formulations of low-foaming cleaning concentrates thickening with water. Table 4 shows the viscosities of the concentrates in their original composition and after dilution with water by a 15 factor of 10 and a factor of 20, i.e. as 10% and 5% aqueous preparations. The viscosity measurements were carried out at a sample temperature of 200C with a Brookfield digital viscosimeter, Model LVDTV-II, using spindle No. 1 (LV Series Code No. 61) rotating at 30 r.p.m. 20 Table 3 Compositions in % by weight SI S2 S3 S4 S5 S6 S7 S8 S9 SIO A 6.0 6.0 6.0 6.0 6.0 6.0 20.0 20.0 1.0 20.0 25 B 3.0 4.0 4.0 4.0 4.0 4.0 13.0 13.0 0.6 1.0 C - - - - - 4.0 - - - Butyl diglycol - - 2.0 2.0 - - - - - i-Propanol 8.0 2.0 2.0 2.0 - - 10.0 - 0.5 10.0 Ethanol - - - - 8.0 - - - - 30 Triethanolamine - - - - - - - 10.0 - - H 2567 15 Table 3 (continued) S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 NaOH 50% - - - 15.0 - - - - - Water 83.0 88.0 86.0 71.0 82.0 86.0 57.0 57.0 87.9 69.0 5 A: bis-(2-hyd roxyethyl)-tallow fatty amine-N-oxide (50% solution) B: C 8

/C

10 alkyl glucoside (70% solution) C: dipropylene glycol monomethyl ether 10 Table 4 Dynamic Brookfield viscosity in mPas SI S2 S3 S4 S5 S6 S7 S8 S9 S10 Concentrate 5 5 5 3 9 3 11.886 78 25 15 10% in water 42 64 71 39 63 35 22.5 110 130 154 5% in water 13 12 51 4 14 9 76.8 130 12 83 Table 5 contains a selection of formulations of film- and gel-forming cleaning concentrates thickenable with water. The viscosities of the 20 concentrates after dilution (in-use concentrations 5 to 15% by weight) are so high that stable gel films are formed on the surfaces to be cleaned. Ethomeen@ S12 N,N-dihydroxyethyl (oleylamide), trademark of Akzo 25 Dobanol@ 45/7 C 14

..

1 5 fatty alcohol ethoxylate - 7EO, trademark of Shell Dobanol@ 25-3S/27 similar product to KSN 27, trademark of Shell Aromox@ T1 2 amine oxide surfactant, trademark of Akzo Empigen@ OH C 14 tertiary amine oxide, trademark of Albright & 30 Wilson H 2567 16 KSN@ 27 dodecyl sulfate - 3 EO, trademark of Albright & Wilson Dequest@ 2000 phosphonate sequesterant, trademark of Monsanto 5 Wardon@ X polyethylene glycol ester/oleic acid, trademark of ICI Trilon@ A trisodium nitrilotriacetate, trademark of BASF Nansa@ 1042 dodecyl benzenesulfonic acid, trademark of Albright & Wilson 10 IMS@ 99 industrial denatured alcohol, a product of Hardings Table 5 Compositions in % by weight 15 GI G2 G3 G4 G5 G6 G7 G8 Ethomeen S12 7.5 - - - - - - Phosphoric acid 70% 30.0 20.0 - - - - - Nitric acid 60% 6.0 1.5 - - - - - 20 Na Xylene sulfonate 30% 9.0 5.0 5.1 - 4.3 - - Dobanol 45/7 2.5 3.0 1.0 0.7 - - - Dobanol 25-3S/27 - - - 6.2 - 10.0 - 14.5 Aromox T 12, 49% - 5.0 3.7 10.5 8.9 10.0 5.5 6.0 Empigen OH 25% - 5.0 12.4 - 2.0 - 2.4 25 Isopropanol - 2.0 - 7.6 3.0 2.6 - Ethanol - - 5.0 - - - - Sodium carbonate - - 5.7 - - - - Sodium gluconate - - - 0.5 - 0.5 - 1.0 Sodium metasilicate - - 2.0 - - - - 30 KSN 27 27% - - 3.8 - 6.0 - 6.0 - H 2567 17 Table 5 (continued) G1 G2 G3 G4 G5 G6 G7 G8 Dodecyl benzene sulfonate - - 2.3 - - - - NaOH, solid - - 1.0 - 12.5 - 22.5 5 NaOH 50% - - - 6.0 - - - NaOH 49% - - - - - - - 6.0 NaOH 47% - - - - - 25 - EDTA 39% - - 0.8 - 2.0 - - Dequest 2000 - - 0.5 0.5 0.5 0.5 - 10 Trilon A 40% - - - 9.0 - 3.0 - Wardon-X - - - 4.0 6.0 6.0 - Nansa 1042 - - - - - - - 1.0 IMS 99 - - - - - - - 7.5 Water Rest Rest Rest Rest Rest Rest Rest Rest

Claims

1. A process for cleaning pipes and containers in the food industry, characterized in that a cleaning composition is applied to the internal surfaces to be cleaned in the form of an aqueous solution of cleaning 5 concentrates thickenable with water and is rinsed off with water after a contact time of 1 to 60 minutes.

2. A process as claimed in claim 1, characterized in that the cleaning composition is used in the "lost" cleaning-in-place (CIP) process.

3. A process as claimed in claim 1 or 2, characterized in that, before 10 application to the internal surfaces, the cleaning concentrate is diluted with water by a factor of 10 to 500 and preferably by a factor of 50 to 200.

4. A process as claimed in one or more of claims 1 to 3, characterized in that cleaning gels thickenable with water are used.

5. A process as claimed in one or more of claims 1 to 3, characterized 15 in that rheopexic cleaning compositions thickenable with water are used.

6. A process as claimed in one or more of claims 1 to 3, characterized in that water-thickenable mixtures of cleaning gels and/or rheopexic cleaners are used.

7. A process as claimed in one or more of claims 1 to 6, characterized 20 in that pipes and/or containers in the brewery industry are cleaned at temperatures of 0 to 10 C.

8. A process as claimed one or more of claims 1 to 6, characterized in that pipes and/or containers in the beverage industry are cleaned at temperatures of 10 to 900C and preferably at temperatures of 20 to 700C. 25

9. A process as claimed in one or more of claims 1 to 6, characterized in that pipes and/or containers in the dairy industry are cleaned at temperatures of 50 to 700C.

10. A process as claimed in one or more of claims 1 to 9, characterized in that the cleaning concentrates contain surface-active components and/or 30 diluents and/or complexing agents and other ingredients of cleaning H 2567 19 compositions.

11. A process as claimed in claim 10, characterized in that amine oxides, optionally in combination with other nonionic and/or anionic surfactants, are used as the surface-active component. 5

12. A process as claimed in claim 10 and/or 11, characterized in that the diluents are selected from the group consisting of ethanol, n- or i-propanol, butanols, glycol, propane or butane diol, glycerol, diglycol, propyl or butyl diglycol, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol 10 methyl ether, diethylene glycol ethyl ether, propylene glycol methyl, ethyl or propyl ether, dipropylene glycol methyl or ethyl ether, methoxy, ethoxy or butoxy triglycol, 1-butoxyethoxy-2-propanol, 3-methyl-3-methoxybutanol, propylene glycol-t-butyl ether and mono-, di- and triethanolamine and mixtures of these solvents. 15

13. A process as claimed in one or more of claims 10 to 12, characterized in that the cleaning concentrates contain other alkalis, chelating agents, builders, other anionic and/or nonionic surfactants, enzymes, preservatives, sequesterants, oxidizing agents, dyes and/or perfumes as further auxiliaries or active substances.