NZ739734B2 - Clean-in-place method and system and composition for the same - Google Patents

Abstract

clean in place (CIP) system which is faster and more efficient decreasing process down time. A method for cleaning product soil from equipment in place, the equipment comprising a first circuit comprising a product supply tank and one or more product nozzles in fluid communication with the product supply tank, and a second circuit comprising a cleaning fluid supply tank and one or more cleaning nozzles in fluid communication with the cleaning fluid supply tank, wherein the first circuit and the second circuit are not the same, the method comprising: (a) draining a liquid product from a product supply tank in fluid communication with the one or more product nozzles in the equipment; (b) adding a first cleaning solution to the product supply tank; (c) applying to the soil the first cleaning solution from the product supply tank through the one or more product nozzles; (d) adding a second cleaning solution to a cleaning fluid supply tank in fluid communication with one or more cleaning nozzles; (e) applying to the soil the second cleaning solution from the cleaning fluid supply tank through the one or more cleaning nozzles; (f) repeating step (c) and step (e) for two or more times; and (g) rinsing the equipment.

Description

A clean in place (CIP) system which is faster and more efficient decreasing process down time.

A method for ng product soil from ent in place, the equipment comprising a first circuit comprising a product supply tank and one or more product nozzles in fluid communication with the product supply tank, and a second circuit sing a cleaning fluid supply tank and one or more cleaning nozzles in fluid ication with the cleaning fluid supply tank, wherein the first circuit and the second circuit are not the same, the method comprising: (a) draining a liquid product from a product supply tank in fluid communication with the one or more product nozzles in the equipment; (b) adding a first cleaning solution to the product supply tank; (c) applying to the soil the first cleaning solution from the product supply tank through the one or more product nozzles; (d) adding a second cleaning solution to a cleaning fluid supply tank in fluid communication with one or more cleaning nozzles; (e) applying to the soil the second cleaning solution from the cleaning fluid supply tank through the one or more cleaning nozzles; (f) repeating step (c) and step (e) for two or more times; and (g) rinsing the equipment.

NZ 739734 CLEAN-IN-PLACE METHOD AND SYSTEM AND COMPOSITION FOR THE SAME This application is being ?led on 29 July 2016, as a PCT International application and claims the bene?t of US. Provisional Application Serial No. 62/199,616, ?led July 31, 2015, which is incorporated by reference herein in its entirety.

FIELD The present sure relates to clean—in-place s and systems, and to compositions for use in clean~in-place s. In particular, the present disclosure relates to clean-in-place methods that include applying a first and second cleaning composition to the surface being cleaned.

BACKGROUND Clean—in—place ("CIP") protocols and methods are used to clean the interior surfaces and other internal components of equipment that cannot be easily embled. Examples of equipment that typically are cleaned using CIP s include various tanks, evaporators, heat exchangers, pipes, and other process equipment. CIP methods are particularly useful in industries that use feed stocks that spoil easily and/or that require a high level of hygiene, such as food and beverage, pharmaceutical, cosmetic, brewing, fuel ethanol, and other similar ries. Soils 2O that contaminate ent surfaces in these industries are characterized by their content of carbohydrates (including osic materials, monosaccharides, disaccharides, oligosaccharides, starches, gums, etc.), proteins, fats, oils, minerals, and other complex materials and mixtures of materials that, when dried and/or heated, can form o-remove soils and residues.

When equipment is cleaned using a CIP protocol, the normal process must be stopped and the equipment emptied of any process materials. Therefore, CIP causes s down time, and particularly with ent that requires long cleaning times (up to 10 to 12 hours), performing CIP can cause a great burden to the normal operations of a plant. Therefore, faster and more ef?cient CIP processes would be advantageous. It is against this background that the present disclosure is made.

SUMMARY A method for cleaning a piece of equipment in place includes a ity of cleaning cycles and optionally a rinse, where each cleaning cycle includes applying a ?rst cleaning solution from a ?rst supply tank through a ?rst set of nozzles; and ng a second ng on from a second supply tank through a second set of nozzles. The ?rst cleaning solution may be applied for about 20 s to about 10 min, and the second cleaning solution for about 1 min to about 60 min. The cleaning cycle can be repeated from 5 to 150 times, and the ?rst and second cleaning ons can be recirculated during the process.

The concentration of active ingredients in the ?rst cleaning solution may be higher than the concentration of active ingredients in the second cleaning solution.

The ?rst and/or second cleaning solutions may include agents that provide a soil disruption . In some embodiments, the ?rst and/or second cleaning solutions include a gas generating agent.

BRIEF DESCRIPTION OF GS is a spray dryer with a CIP system. shows a schematic depiction of a CIP system. is a ?ow chart of a CIP method according to an embodiment. shows a schematic depiction of a CIP system used in the method of shows a schematic depiction of a CIP system used in the method of is a graphical representation of the results of Example 2.

ED DESCRIPTION The present disclosure relates to clean-in-place methods and systems and compositions for use in clean-in-place methods. In particular, the present disclosure s to clean-in-place methods that include alternating spraying a ?rst composition and a second composition to the surface being cleaned. In some embodiments, the ?rst composition es a gas generating composition.

The term "about" is used here in conjunction with numeric values to include normal variations in measurements as expected by s skilled in the art, and is understood have the same meaning as "approximately" and to cover a typical margin of error, such as j; 5 % of the stated value.

The methods of the present sure may be particularly suitable for systems that include two or more spray systems, for example, a ?rst spray system that is used for spraying a product during normal operation, and a second spray system that is used to spray ng solution during CIP cleaning. The methods be con?gured may also be suitable for s that include a spray system that can to draw from two or more storage vessels, for example, one storage vessel that is used to store product in normal operation, and a second storage vessel that is used to store cleaning solution.

Many industrial processes that utilize CIP methods for cleaning experience hard-to-remove soils that require long ng times. CIP processes can take l hours to complete, causing undesirable downtime as the production process cannot be operated simultaneously with the CIP process. Many food and beverage soils are particularly dif?cult to remove if the soil is thermally degraded e the material has been heated during processing. For example, products may have been heated to cook, sterilize (e. g., to rize), condense, or todry. The term "thermally degraded" is used to refer to material that has been exposed to heat and as a result has undergone changes to the chemical structure of the material, such as denaturing and cross linking reactions of proteins, carbohydrates, fats, and oils. Most food and beverage products include either protein, fat, carbohydrates, or a ation thereof.

One particularly challenging CIP cleaning application is a large vertical milk powder) or starch. spray dryer used to dry dairy ts (e.g., to produce dried Such dryers are often conical in shape and can be as large as 60 to 90 feet in height and 12 to 18 feet in diameter at the top. In particular, spray dryers used to dry dairy includes protein, fat, may accumulate large amounts of dry, on product that and carbohydrates on the inside walls of the dryer chamber. A schematic drawing of atypical spray dryer 100 is shown in FIGURE 1A. The wet product is introduced h spray nozzles 127 at the top of the drying chamber 110, where the product is atomized into small ts. As the droplets fall down inside the drying chamber 110, hot air (typically about 250 °F) is counter-?own from the bottom to dry the wet particles. The dried particles are collected at the bottom of the drying chamber and can be removed for further processing (e.g., in a cyclone or ?uid bed dryer). r, during the process, some of the product lands and remains on the walls 111 of the chamber 110 rather than falling to the bottom, and over time ps a hard-to—remove layer of on soil.

The spray dryer 100 can include a cleaning system 130 that is used for CIP cleaning. A simpli?ed schematic of the cleaning system 130 is shown in FIGURE 1B. A similar cleaning system 130 can be used with other types of ent, such as other types of dryers (e.g., ?uid bed dryers, cone , or drum dryers), tanks, evaporators, heat exchangers, pipes, separators, homogenizers, pasteurizers, cooling towers, cabinet ovens, combi ovens, belt sprays, paper mill equipment, re?nery distillation towers, and other process equipment. The cleaning system 130 can include a cleaning ?uid supply tank 131 that is connected to spray nozzles 138 by line 135. The spray nozzles 138 can be constructed to spray the cleaning ?uid at high pressure to the inside walls 211 of the vessel 210 to clean on soil. The exemplary spray dryer system shown in FIGURE 1A includes spray nozzles 137 on the sides and a central spray nozzle 136 in the middle of the chamber 110.

The cleaning ?uid can be supplied to the spray nozzles 136, 137 or 138 at an elevated pressure provided by a pump 133. The pump 133 should be selected to provide a pressure ed by the particular spray nozzles. For example, a rotary spray nozzle typically requires a higher pressure than regular spray nozzles. The nozzle con?guration can be modi?ed to ze the nozzles for the selected cleaning solution. Movable nozzles can be utilized to ensure coverage of hard-to reach areas of equipment, such as bends, elbows, or comers.

The cleaning may be done at a temperature of about 100 °F or higher, depending on the soil to be removed. The ng system may include a heater to bring the cleaning solutions to the desired temperature.

The spent cleaning ?uid from the CIP spray is collected at the bottom and can be circulated back into the supply tank 131, through a recirculation line 139. The spent cleaning ?uid can be ?ltered before reuse. In some embodiments, the ulation line 139 may further comprise a screen or a ?lter to remove particulate matter, e. g., soil particles removed by the cleaning ?uid.

A typical CIP cycle to clean a dairy spray dryer using existing methods can last as long as 12 to 18 hours, during which a cleaning solution of about 0.5 to 2 % caustic is circulated through the CIP . Because of the large size of the drying chamber, the CIP system consumes large amounts of water. In some applications, the cleaning solution cannot be effectively recirculated because of the type of soil being removed. For example, soils that include high concentrations of starch (e. g., in a starch spray dryer) cause starch and starch—based reaction products (e. g., gelatinized starch) to accumulate in the cleaning solution so that the cleaning solution cannot be recirculated.

The methods of the present disclosure can be particularly useful for cleaning soils containing proteins, carbohydrates, and/or fats in spray dryers or other equipment. ing to an embodiment and generically shown in the ?ow chart of FIGURE 2, the method includes a CIP cycle of applying a ?rst cleaning on from a ?rst spray system, applying a second cleaning solution from a second spray , and repeating the CIP cycle until a desired level of ng is achieved.

Prior to ing the CIP cycle, the system (e. g., the product supply tank) is emptied of any product that could be left in it and the dryer or other equipment can be pre-rinsed with water or other t. nsing done through the product nozzles may also help remove remaining product from the product nozzles. The in which a rinse, acidic or basic process can also include any other contacting step functional ?uid, solvent or other cleaning component such as hot water, cold water, etc. can be ted with the equipment at any step or between steps during the with water or a process. The CIP cycle may also include a ?nal rinse step, e. g., composition comprising an antimicrobial agent, to prepare the system for subsequent food grade production. If the soil load of the re-circulating cleaning solution becomes too high, the supply tank may be drained and re-?lled with fresh cleaning solution.

Bene?cially, the ?rst cleaning solution can provide a soil disruption effect, making the second cleaning on more effective. The term "soil disruption effect" is used here to refer to ing, destruction, and/or displacement of soil on the ?rst a surface. Without wishing to be bound by theory, it is thought that when cleaning solution penetrates a layer of soil, the cleaning action generated by the first cleaning solution ts the soil , breaks up the soil layer, and loosens it from the surface. The disrupted soil can then be d by the use of the second cleaning solution providing higher pressure impingement forces. In some embodiments, the soil disruption effect is brought on by a reaction n active ingredients in the ?rst cleaning solution and the second cleaning solution. In some embodiments, the cleaning action is generated by bubbles or foaming.

According to at least one embodiment, the ?rst cleaning solution can be applied from a ?rst supply tank and the second cleaning solution can be applied from a second supply tank. For e, in some embodiments used to clean a spray dryer, the ?rst cleaning on is drawn from the product supply tank 121 and sprayed through the product spray nozzles 127 at the top of a spray dryer for a ?rst length of time, and the second ng solution is drawn from the CIP supply tank (cleaning ?uid supply tank 131 in FIGURE 1A) and sprayed through the CIP cleaning nozzles 136, 137 for a second length of time. The upright spray dryer (shown in FIGURE 1A) lends itself well to the present method because it already includes two sets of spray nozzles. Other types of equipment, such as other dryers, tanks, evaporators, heat exchangers, pipes, separators, homogenizers, pasteurizers, cooling towers, cabinet ovens, combi ovens, belt sprays, paper mill equipment, re?nery distillation , and other s equipment could be outfitted with a second set of spray nozzles to odate the present cleaning method.

Alternatively, the spray nozzles can be adapted to draw cleaning solutions from two separate supply tanks.

The ?rst and second cleaning solutions can be independently applied at ambient temperature or at an ed temperature. The ?rst and second cleaning solutions can also be applied independently at an elevated pressure. For example, if a high pressure CIP cleaning nozzle is used, the solution applied through the nozzle can be applied at a pressure ranging from 50 psi up to and exceeding 150 psi. In some ments, the second cleaning on is applied through CIP cleaning nozzles at a pressure of about 100 to about 500 psi, or about 150 to about 300 psi.

The product spray nozzles 127 in a typical spray dryer can be non—pressurized and are not necessarily adapted for getting complete coverage of the inside walls 111 of the drying chamber 110. However, counter flow air can optionally be utilized to improve coverage of the walls with the cleaning solution (e. g., the ?rst cleaning solution). The nozzle ration can also be adapted, or the system can be ed with different types of nozzles to achieve a desired cleaning outcome, such as better coverage, high pressure, rotating, or foaming nozzles. 2O According to an alternative embodiment used in a cleaning system 230 shown in FIGURE 3A, the ?rst cleaning solution is provided in a ?rst supply tank 121 and the second cleaning on is provided in a second supply tank 131, and each tank is connected to and in ?uid communication with the nozzles 138 through lines 125, 135. The system 330 may include a switch 410 (e.g., a switch valve) for switching the supply to the nozzles 138 from the ?rst supply tank 121 to the second supply tank 131 and back. During cleaning, the nozzles 138 can be ?rst supplied with the ?rst cleaning solution from the ?rst supply tank 121 for a ?rst length of time, then with the second cleaning solution from the second supply tank 131 for a second length of time. 3O In another alternative embodiment shown in FIGURE 3B, the cleaning system 330 es two or more separate circuits 331, 332, each with a supply tank 121, 131, pump 123, 133, supply line 125, 135, spray nozzles 128, 138, and optionally recirculation line 129, 139. The ?rst ng solution can be provided in the ?rst supply tank 121 of the ?rst cleaning circuit 331, and the second cleaning on in the second supply tank 131 of the second cleaning circuit 332. In a typical spray dryer system, only the second circuit 332 (usually the CIP circuit) includes a ulation line 139. Cleaning solution from the ?rst supply tank 121 would be recirculated into the second circuit 332 through the recirculation line 139.

In some embodiments, the ?rst circuit 332 also includes a recirculation line 139, and the ?rst and second ng solutions can be recirculated into the ?rst supply tank 121.

CIP tanks ed in typical spray dryer systems can be large, up to hundreds of gallons in size. Any chemistry that is ed in a cleaning solution in the CIP supply tank gets diluted with a large volume of water, and therefore needs to be included in a substantial amount. Providing the chemistry at a high concentration in the large tank can be cost prohibitive. By providing a cleaning solution in a separate supply tank (i.e., the ?rst supply tank), the solution can be provided at a higher concentration because the delivery ?ow rate is typically much smaller than the CIP supply tank. The present method provides a cost—effective way to supply a concentrated, heavy duty cleaner for the CIP cycle.

The ?rst and second cleaning solutions can comprise different chemistries, different concentrations, or be the same. In one embodiment, the ?rst cleaning solution has a different and more concentrated chemistry than the second cleaning solution, and is supplied to the nozzles 138 for a shorter length of time than the second ng solution. In another embodiment, the ?rst cleaning solution comprises the same chemistry as the second ng solution. However, the ?rst cleaning solution may have a higher concentration of active ingredients than the second cleaning solution, or vice versa. The ?rst and second cleaning solutions can also be applied at different atures, and one or both of the cleaning solutions The temperature of may be applied at either ambient or at ed temperatures. each cleaning solution can be adjusted based on the soil to be removed and/or the chemistry in the cleaning solution.

In one embodiment the ?rst and second cleaning solutions have the same chemistry but the ?rst cleaning solution is more concentrated than the second cleaning solution. Used cleaning solution can be collected after spraying, optionally ?ltered to remove solid particles, and directed into one of the supply tanks, for example, the second supply tank. If the ?rst cleaning solution is more concentrated, and the used solution is collected and directed into the second supply tank, the mixing of the used ?rst ng solution with the second cleaning solution in the tank would cause the second cleaning solution to become more concentrated hout the plurality of cleaning cycles.

In one embodiment the ?rst and second cleaning solutions have different chemistries, and the ?rst cleaning solution may also comprise a higher tration of active ingredients than the second cleaning solution. If the used ?rst cleaning solution is collected after spraying and optionally ?ltered and directed into the second supply tank, the components (e. g., the active ingredients) of the ?rst cleaning solution may react with the components (e.g., the active ingredients) of the second cleaning solution and/or may override the components of the second cleaning solution. For example, if one of the ?rst and second ng solutions is basic and the other is , the acid and base can react together when mixed. In such a case, the second cleaning solution can be replenished during or after the cleaning procedure.

In n embodiments, a third, fourth, or subsequent cleaning solution can be used. For example, in a ?rst part of the cleaning cycle, ?rst and second cleaning solutions are applied, and after applying the ?rst and second cleaning solutions to the surface, the supply tanks can be d and provided with third and/or fourth cleaning ons to be d in a second part of the cleaning cycle. Alternatively, additional supply tanks can be provided, and the third, fourth, or consecutive cleaning solutions can be provided in the additional tanks.

The chemistry in the cleaning ons can be selected based on the soil to be removed. For example, a combination of de and surfactant followed by alkali can be effective in cleaning soils that contain protein, carbohydrates, and/or starch. Soils containing fats can bene?t from adding a solvent to the cleaning solution. s can be utilized to clean soils containing, for example, protein or In the case of the dairy spray dryer (FIGURE 1A), a typical CIP solution is a relatively dilute caustic that is sprayed at high volume to clean the chamber 110.

However, according to an embodiment of the present method, because the product spray nozzles 127 are connected to a product supply tank 121, a different and ageously more concentrated chemistry can be applied through the product spray nozzles 127. In one ary embodiment, a concentrated pre-treatment chemistry is applied from the product supply tank 121 through the product spray nozzles 127 onto the walls 111 of the dryer chamber, and a more dilute cleaning solution (e.g., a CIP solution comprising 0.1 to 2 % caustic) is then applied from the cleaning ?uid supply tank 131 through the CIP spray nozzles 136, 137. The cycle of pre—treatment and CIP ation can be repeated le times, and can optionally be followed by a clean water rinse.

TIMING The present method includes preferably a plurality of application or cleaning , where each cycle comprises applying the ?rst ng solution for a ?rst length of time and applying the second cleaning solution for a second length of time.

The plurality of application cycles can be any le number of cycles, such as 3 to 200 cycles, 5 to 150 cycles, 10 to 100 cycles, 20 to 75 cycles, or 30 to 60 cycles.

The length of time of applying the ?rst and second cleaning solutions can be adjusted based on the chemistries used in each cleaning solution, the concentration of the chemistry used, and on the type and amount of soil that needs to be removed.

In some embodiments, the ?rst length of time is shorter than the second length of time. For example, the ?rst cleaning solution can be applied for about 30 s to about min, about 45 s to about 15 min, about 1 to about 10 min, about 90 s to about 5 min, or any suitable length of time. In some embodiments the ?rst length of time is at least 20 s, 30 s, 40 s, 50 s, 60 s, 90 s, 2 min, 2 min 30 s, 3 min, 4 min, or 5 min or longer. In some embodiments, the ?rst length of time is no more than 60 min, 30 min, 25 min, 20 min, 15 min, 10 min, 8 min, 7 min, 6 min, 5 min, 4 min, 3 min, 2 min 30 s, or 2 min.

The method may optionally include a soak time (i.e., a delay) between the application of the ?rst cleaning solution and the second cleaning solution. The soak time may be from 0 to about 5 min, or from 0 to about 3 min long. In some embodiments, there is essentially no delay between the application of the ?rst cleaning solution and the second cleaning solution, except for possibly a minimal delay caused by the stopping of one spray system and starting of another.

The second length of time can be any length of time as adjusted based on the chemistry and the soil to be removed. The second length of time can be about I to 150 min, about 1 to 120 min, about 1 to 90 min, about 1 to 60 min, about 2 to 45 min, about 3 to 30 min, about 5 to 20 min, or about 10 to 18 min.

The cleaning cycle can be repeated any le number of times, such as 3 to 200 times, 5 to 150 times, or 10 to 100 times. In one ary embodiment, the ?rst length of time is about 3 to 5 min, and the second length of time is about 13 to 17 min, and the cycle is repeated about 40—50 times. The cleaning cycles follow each other in quick succession, such that the next cleaning cycle begins essentially immediately after the previous cleaning cycle is over, or with minimal lag time as allowed by operation of the ent. For example, the lag time may be up to about a few minutes (e.g., about 1, 2, 3, 4, 5, or 6 minutes). In some cases, there is not lag time, or the lag time is virtually nonexistent (i.e., about 0 minutes, or less than 30 s or less than 60 seconds). The plurality of cleaning cycles (e.g., 3 to 200 cycles, 5 to 150 cycles, or 10 to 100 cycles) form one instance of CIP cleaning, where normal use of the equipment (e.g., tion) is d for the duration of the cleaning and is not started until the cleaning is ?nished.

COMPOSITION Any suitable cleaning chemistries can be used to provide the ?rst and second cleaning solutions used in the . The ?rst and second ng solutions can comprise the same or different chemistries, and can have the same or different concentrations. In some embodiments, the ?rst cleaning solution is different from the second cleaning solution and/or is more concentrated. For example, the ?rst cleaning solution can comprise active ingredients at a concentration of up to 20 wt- %, 18 wt-%, 16 wt—%, 15 wt-%,14 wt-%, 13 wt-%, 12 wt-%, 11 wt-%, or up to 10 wt-%. In at least some of the embodiments, the ?rst cleaning solution comprises at least 2 wt—%, 3 wt-%, 4 wt-%, 5 wt-%, 6 wt-%, 7 wt-%, 8 wt—%, 9 wt-%, or at least wt-% of active ients. The term "active ingredients" is used here to refer to ingredients that actively contribute to the cleaning, as opposed to ingredients that are used to dilute or otherwise formulate (e. g., thicken, ize, colorize, preserve, etc.) the composition. In some embodiments, the second ng solution comprises from 0.1 to 8 wt-%, from 0.2 to 6 wt—%, from 0.2 to 5 wt~%, from 0.2 to 4 wt-%, from 0.3 to 3 wt-%, from 0.4 to 2.5 wt-%, or from 0.5 to 2 wt-% of active ingredients. For e, the second cleaning solution can be a CIP ng solution including about 0.1 to 5 wt-%, or about 0.5 to 2 wt-% caustic (NaOH) in water.

In some embodiments, the ?rst cleaning solution comprises an oxidizing agent or an oxidizer, such as a peroxide, peroxyacids, or other peroxygen compound.

The resulting solution is particularly effective against protein and starch soils.

Further, reaction of the oxygen compounds with the soil, especially when combined with an alkaline , creates vigorous mechanical action on and within the soil, which enhances removal of the soil.

Suitable oxidants include chlorites, bromine, bromates, bromine monochloride, iodine, iodine loride, iodates, perrnanganates, es, nitric acid, borates, ates, and s oxidants such as ozone, oxygen, chlorine dioxide, chlorine, and tives thereof. Peroxygen compounds, which include peroxides and various percarboxylic acids, including percarbonates, are suitable.

Peroxycarboxylic (or percarboxylic) acids generally have the formula R(CO3H)n, where, for example, R is an alkyl, arylalkyl, cycloalkyl, aromatic, or heterocyclic group, and n is one, two, or three, and named by pre?xing the parent acid with "peroxy." The R group can be saturated or unsaturated as well as substituted or unsubstituted. In medium chain peroxycarboxylic (or percarboxylic) acids R is a C5—C1] alkyl group, a C5—C1] cycloalkyl, a C5—Cnarylalky1 group, C5- C11 aryl group, or a C5-C11heterocyclic group; and n is one, two, or three. In short chain fatty acids, R is C1-C4 and n is one, two, or three.

Examples of carboxylic acids include peroxypentanoic, peroxyhexanoic, peroxyheptanoic, peroxyoctanoic, peroxynonanoic, peroxyisononanoic, peroxydecanoic, peroxyundecanoic, peroxydodecanoic, peroxyascorbic, adipic, peroxycitric, peroxypimelic, or peroxysuberic acid, mixtures thereof, and the like.

Branched chain peroxycarboxylic acids include peroxyisopentanoic, isononanoic, peroxyisohexanoic, peroxyisoheptanoic, peroxyisooctanoic, peroxyisononanoic, peroxyisodecanoic, peroxyisoundecanoic, peroxyisododecanoic, peroxyneopentanoic, peroxyneohexanoic, peroxyneoheptanoic, peroxyneooctanoic, peroxyneononanoic, peroxyneodecanoic, peroxyneoundecanoic, peroxyneododecanoic, mixtures thereof, and the like.

Typical peroxygen compounds may include en peroxide (H202), peracetic acid, anoic acid, a fate, a perborate, or a bonate.

The amount of oxidant in the pre-treatment solution may be at least 0.01 wt— % and less than 2 wt-%. In some ments, the cleaning solution comprises from about 0.01 to 1 wt-%; about 0.05 to about 0.50 wt—%; about 0.1 to about 0.4 wt-%, or about 0.2 to about 0.3 wt-% of oxidant. If the composition also comprises an acid, suitable ratios of oxidant to acid are generally from 1:1 to 1:50, from 1:2 to 1:40, from 1:3 to 1:30, from 1:4 to 1:25, or from 1:5 to 1:20. In an exemplary embodiment, the cleaning solution comprises 0.25 wt-% to 10 wt-% phosphoric acid and 50—5000 ppm (0.005 wt-% to 0.5 wt—%) hydrogen peroxide, or in particular, about 0.75 wt-% phosphoric acid and about 500 ppm (0.05 wt-%) hydrogen peroxide (a ratio of 1:15 of oxidantzacid).

Suitable acids include phosphoric acid, nitric acid, hydrochloric acid, sulfuric acid, acetic acid, citric acid, lactic acid, formic acid, glycolic acid, methane ic acid, sulfamic acid, and mixtures thereof. When the acid is used in combination with an oxidant, the cleaning solution can comprise about 0.1 to about 12 wt-%, about 0.2 to about 10 wt—%, about 0.3 to about 8.0 wt-%, about 0.5 to about 6.0 wt—%, about 0.8~ to about 4.0 wt-%, about 1.0 to about 3.0 wt-%, or about 1.5 to about 2.5 wt-% of acid.

In an embodiment where the ?rst cleaning solution contains hydrogen peroxide and the second cleaning solution contains sodium hydroxide, the ng cycle of ?rst cleaning solution followed by the second cleaning solution creates oxygen s formed by the destruction of the hydrogen peroxide. The oxygen bubbles can be effective in breaking down on soil, such as soil formed in a spray dryer used to produce dried milk or starch.

According to an embodiment, the ?rst cleaning solution may include a gas generating solution that generates carbon dioxide or another gas on or in the soil to provide the soil disruption effect. The gas generating solution can se at least a ?rst gas generating compound and a second gas generating compound, where the ?rst and second gas generating compounds react together to generate gas. For example, the gas generating on can comprise a source of -dioxide— producing salt and an acid. Exemplary gases other than carbon dioxide that can be generated by the gas generating solution include chlorine dioxide, chlorine, and oxygen.

Suitable carbon-dioxide-producing salts include, for example, carbonate salt, bicarbonate salt, percarbonate salt, a carbonate salt, and mixtures thereof.’The carbon-dioxide—producing salt can be a carbonate, bicarbonate, percarbonate, or sesquicarbonate salt of sodium, potassium, lithium, ammonium, calcium, magnesium, or propylene. In some embodiments, the salt is selected from sodium carbonate, sodium bicarbonate, sodium percarbonate, sodium sesquicarbonate; potassium carbonate, potassium onate, potassium percarbonate, potassium sesquicarbonate; lithium carbonate, lithium bicarbonate, m percarbonate, lithium sesQuicarbonate; ammonium carbonate, ammonium onate; calcium carbonate, magnesium carbonate, propylene carbonate, and es thereof. The cleaning solution can comprise about 0.1 to about 7.0 wt-%, about 0.2 to about 5.0 wt-%, or about 0.3 to about 3.0 wt-% of the carbon—dioxide-producing salt.

Gas generating solutions that produce a chlorine containing gas (e. g., chlorine e) can include, for e, sodium hypochlorite and an acid. In some embodiments, the gas generating solution produces two or more different gases, e. g., carbon dioxide and chlorine containing gas. Such a gas generating solution may contain, for example, a carbon-dioxide—producing salt (e. g., a carbonate salt) and sodium hypochlorite.

The second gas generating compound can be any suitable compound that is capable of reacting with the ?rst gas generating compound to te gas. For example, the second gas generating compound may be an acid. Exemplary acids include phosphoric acid, nitric acid, hydrochloric acid, sulfuric acid, acetic acid, citric acid, lactic acid, formic acid, glycolic acid, methane sulfonic acid, sulfamic acid, and mixtures thereof. The amount of acid can be‘adjusted based on various considerations, such as the acid selected, the amount and type of ?rst gas generating compound, and the soil to be removed. The cleaning solution can se about 0.1 to about 10 wt-%, about 0.2 to about 8.0 wt-%, about 0.3 to about 6.0 wt—%, about 0.5 to about 5 wt-%, about 0.8 to about 4 wt—%, about 1.0 to about 3.0 wt-%, or about 1.5 to about 2.5 wt-% of acid. In an exemplary ment, the acid comprises a strong l acid, e.g., oric, nitric, or sulfuric acid or a combination thereof, and is present at about 1.0, 1.5, 2.0, 2.5, or 3.0 wt-%.

According to some embodiments, the ?rst and/0r second cleaning solution comprises a st. Useful catalysts include, for example, transition metal Complexes, (e.g., complexes of manganese,rmolybdenum, chromium, copper, iron, or cobalt). Exemplary sources of manganese ions include, but are not d to, manganese (II) sulfate, manganese (II) chloride, manganese (II) oxide, ese (III) oxide, manganese (IV) oxide, manganese (II) e and combinations thereof.

An exemplary source of iron includes iron gluconate. In some embodiments, the cleaning can be more ef?cient at a lower temperature (e.g., at temperatures of between 100 °F-130°F), and including a catalyst in the cleaning solution may help induce formation of gas bubbles. For example, when using a peroxide solution to clean starch residue, iron gluconate catalyst can be used to accelerate degradation of the peroxide compounds at lower temperatures to increase generation of gas bubbles.

In some embodiments, the first ng solution does not contain a gas generating composition. In such solutions, the cleaning effect can be achieved by, for example, a combination of one or more solvents and one or more surfactants, or by using one or more s. In some embodiments, the first cleaning solution contains an enzyme and /or a surfactant, and the second cleaning solution ns a gas generating ition.

In one ary embodiment, a dual functioning surfactant can be used. A cleaning solution that comprises a nonionic surfactant can be sprayed at a temperature that is below the cloud point of the nonionic surfactant, causing the cleaning solution to foam and to better adhere to the surface of the equipment being cleaned, thus sing contact time between the surface and the cleaning solution.

A subsequent ng solution (e.g., second cleaning solution) can then be applied at a temperature that is above the cloud point of the nonionic surfactant, changing the behavior of the nonionic surfactant to a de-foamer.

OTHER ENTS The ?rst and second cleaning solutions ctively "cleaning solutions") may also comprise alkaline components, surfactants, solvents, builders, additional components. Suitable alkaline components include any alkaline components typically used in cleaning compositions, including NaOH, KOH, triethanol amine (TEA), diethanol amine (DEA), monoethanolamine (MBA), carbonates, bicarbonates, percarbonates, sesquicarbonates, morpholine, sodium metasilicate, potassium silicate, etc. le surfactants that can be used in the cleaning solutions include anionic, cationic, nonionic, and zwitterionic surfactants. The cleaning compositions 0.1 may comprise about 0.01 to about 3 Wt-%, about 0.05 to about 2 wt-%, or about to about 0.5 wt-% of surfactants. The surfactant may be a combination of surfactants. In an embodiment, at least one of the Surfactants is nonionic.

Nonionic Surfactants In some embodiments, the surfactant comprises a nonionic surfactant.

Nonionic surfactants improve soil removal and can reduce the contact angle of the on on the surface being treated.

Examples of le nonionic surfactants include alkyl-, aryl-, and arylalkyl- amines and their derivatives, , alkoxylates, alkylpolyglycosides and their derivatives, and amides and their derivatives. Additional useful nonionic surfactants include those having a polyalkylene oxide r as a portion of the surfactant molecule.

Such nonionic surfactants e, for example, ne-, benzyl-, methyl-, , propyl-, butyl- and other like alkyl-capped polyoxyethylene and/or polyoxypropylene glycol ethers of fatty alcohols; polyalkylene oxide free nonionics such as alkyl polyglycosides; sorbitan and sucrose esters and their ethoxylates; alkoxylated ethylene diamine; carboxylic acid esters such as glycerol esters, polyoxyethylene esters, lated and glycol esters of fatty acids, and the like; carboxylic amides such as diethanolamine condensates, monoalkanolamine condensates, polyoxyethylene fatty acid amides, and the like; and ethoxylated amines and ether amines and other like nonionic compounds. ne surfactants can also be used. Nonionic surfactants having a polyalkylene oxide polymer n include nonionic surfactants of C6-C24 alcohol ethoxylates having .1 to about 20 ethylene oxide groups; C6-C24 alkylphenol ethoxylates having 1 to about 100 oxide groups; C6-C24 alkylpolyglycosides having 1 to about 20 glycoside . ethylene ; C6-C24 fatty acid ester ethoxylates, propoxylates or glycerides; and C4—C24 mono or dialkanolamides.

Examples of aming, low foaming, or defoaming nonionic surfactants include block p0lyoxypropylene—polyoxyethylene polymeric compounds with hydrophobic blocks on the e (ends) of the molecule, and nonionic surfactants modi?ed by "capping" or "end blocking" termmal hydroxyl groups by reaCtion with a small hydrophobic molecule or by converting terminal hydroxyl groups to chloride groups. Other examples of non-foaming nonionic surfactants include 3O a1kylphenoxypolyethoxyalkanols; polyalkylene glycol condensates; defoaming nonionic surfactants having a general a Z[(OR)nOH]Z where Zis alkoxylatable material, R is a l, n is lO-2,000, and z is ined by the number of ve oxyalkylatable groups; and ated yalkylene compounds.

Anionic Surfactants Anionic surfactants are useful as detersive surfactants, but also as gelling agents or as part of a gelling or ning system, as solubilizers, and for hydrotropic effect and cloud point control. The composition may include one or more anionic surfactants. Suitable anionic surfactants for the present composition include: carboxylic acids and their salts, such as alkanoic acids and alkanoates, ester carboxylic acids (e.g. alkyl succinates), ether carboxylic acids, and the like; phosphoric acid esters and their salts; sulfonic acids and their salts, such as isethionates, alkylaryl sulfonates, alkyl sulfonates, sulfosuccinates; and sulfuric acid esters and their salts, such as alkyl ether sulfates, alkyl es, and the like.

Cationic Surfactants Examples of suitable cationic surfactants include amines, such as alkylamines and their salts, alkyl olines, ethoxylated , and quaternary ammonium compounds and their salts. Other cationic surfactants include sulfur nium) and phosphorus (phosphonium) based compounds that are analogous to the amine compounds.

Amphoteric and Zwitterionic Surfactants Amphoteric and zwitterionic surfactants include derivatives of secondary and tertiary amines, derivatives of heterocyclic secondary and tertiary amines, or derivatives of quaternary ammonium, quaternary phosphonium or tertiary sulfonium compounds. The ammonium, onium, or sulfonium nds can be substituted with aliphatic substituents, e.g., alkyl, alkenyl, or hydroxyalkyl; alkylene or hydroxy alkylene; or carboxylate, sulfonate, sulfate, phosphonate, or phosphate zwitterionic surfactants for groups. Betaine and sultaine surfactants are exemplary use in the present composition.

Builders The cleaning solutions may also include one or more builders. Builders include chelating agents (chelators), sequestering agents (sequestrants), detergents, and the like. Builders can be used to stabilize the composition or solution. Examples of suitable builders include phosphonic acids and phosphonates, phosphates, aminocarboxylates and their derivatives, pyrophosphates, polyphosphates, ethylenediamine and ethylenetriamine derivatives, hydroxyacids, and mono-, di-, and tri—carboxylates and their corresponding acids. Other builders include aluminosilicates, nitroloacetates and their derivatives, and mixtures thereof. Still other rs include aminocarboxylates, including salts of ethylenediaminetetraacetic acid (EDT A), hydroxyethylenediaminetetraacetic acid (HEDTA), and diethylenetriaininepentaacetic acid. Preferred builders are water soluble. ularly preferred builders e EDTA (including tetra sodium EDTA), TKPP tassium polyphosphate), PAA (polyacrylic acid) and its salts, phosphonobutane carboxylic acid, and sodium gluconate.

The cleaning solutions may se about 0.05 to about 7 wt-%, about 0.1 to about 5 wt-%, about 0.2 to about 4 wt-%, about 0.3 to about 3 wt—%, or about 0.5 to about 2 wt—% of a builder.

Solvents The cleaning solutions may include one Or more organic solvents. Suitable solvents include c solvents, such as, esters, ethers, ketones, amines, mineral spirits, aromatic ts, non—aromatic solvents, and ed and chlorinated hydrocarbons. Preferred solvents include water soluble glycol ethers. Examples of glycol ethers include dipropylene glycol methyl ether, diethylene glycol methyl ether, propylene glycol methyl ether, and ethylene glycol monobutyl ether, commercially available as DOWANOL® DPM, DOWANOL® DM, DOWANOL® PM, and DOWANOL® EB, respectively, from Dow Chemical Company, Midland, MI. In n ments, preferred solvents are non-?ammable.

Enzymes Enzymes can be used in the cleaning solutions to break up soils, such as starch, protein, or oil based soils. Exemplary enzymes include proteases, amylases, lipases, and other suitable enzymes. The composition can be tailored to the type of soil to be cleaned so that, for example, protein-based soils are targeted with proteases, starch-based soils with amylases, and oil—based soils with lipases.

The solutions may comprise additional components to provide desired properties or functionality. For example, the ons can include chelating or sequestering agents, sanitizers or antimicrobial agents, dyes, rheological modi?ers (e. g., gelling agents, thickeners, and the like), pH modi?ers (acids or , preservatives, processing aids, corrosion inhibitors, or other functional ients.

The pH of the cleaning solutions can be adjusted based on the choice of acid cleaning or alkaline cleaning for various soil types. In some embodiments,the ?rst cleaning ition has a pH of 1.5 to 14. For example, if an alkaline cleaning composition is used, the pH may be in the range from 7 to 14, from 8 to 13, or from 9 to 12. ary alkaline cleaning solutions include solutions comprising hydroxides or carbonates or other alkaline . In an ment, an alkaline ?rst cleaning solution that contains a carbonate (e.g., potassium ate) and has a pH above 7 can be followed up by a second cleaning on that is acidic (pH less than 7) that neutralizes the ?rst cleaning solution and generates C02 bubbles for improved mechanical ng action. If the used alkaline solution is directed into the second supply tank and mixed with the second cleaning solution there, the pH of the second cleaning solution can be adjusted by adding more acid throughout the is used, the pH process to maintain its acidic .pH. If an acidic ng composition less than 5, less than 4, may be in less than 7, less than 6.5, less than 6, less than 5.5, or less than 3. In some embodiments the pH is between 1 and 6, or between 1.5 and EXAMPLES Example 1 The CIP method can be used to clean a large conical dairy spray dryer as shown in FIGURE 1. Various combinations of cleaning solutions can be prepared as shown in TABLE 1. In the table, each ?rst cleaning solution is denoted "A" and each second cleaning solution is denoted "B." Each cleaning solution is prepared and mixed with water at the noted inclusion rate to produce a use solution.

TABLE 1. Prearation of Cleanin Solutions. 21:40 _ "___-SodiumH?droxide(50%) - 46.00 __— Potassium Carbonate (40 %) ___-— ' _—-_— 'c Acid (50 %)' Nitric Acid (67.2 %) ‘ _--__ Pol O acr lic Acid Sodium Salt N O Hydroxyethylene diphosphonic Acid 0.50 >-‘ OO (60 %) (50%) - -—_—-__ ' ————_ Surfactant (STEFAN) The Various compositions (A/B) can also be combined so that the ng lO solution A of Combination 1 can be ed with the cleaning solution B of any Combination 2. or 3; ng solution A of Combination 2 can be combined with cleaning solution B of Combination 1 or 3, and cleaning solution A of Combination 3 can be combined with cleaning solution B of Combination 1 or 2.

The ing use solution concentrations are shown in TABLE 2.

TABLE 2. Use Solutions OoBE= a:'2’.o: .... oEE:1:9 ST.0= N ation 3 Sodium Hydroxide 0.12- 0.025- 023 0.05 Potassium Carbonate _ 0.2-0.4 _ Ferric Sulfate 9 Mole Hydrate 0.0042 —Gluconic Acid 0.01 Phosphoric Acid Hydrogen Peroxide 0.68- Sodium Cumene Sulfonate 0.076- Polyacrylic Acid Sodium Salt 0.01- Hydroxyethylene phonic 0.006- Acid 0.015 Phosphonobutanetricarboxylic Surfactant (DEI—IYPON) 0.04- Surfactant (STEFAN) .O o '7‘ The cleaning cycle is started by emptying the product supply tank of any product, pre—rinsing the dryer with water h the product spray nozzles, ?lling the product supply tank with the ?rst cleaning solution, delivering the ?rst cleaning solution (A) from the product supply tank and applying through product spray nozzles at about 45 gal/min for about 3 minutes. The second cleaning solution (B) is then red from a CIP supply tank and applied through CIP spray nozzles, at about 100 gal/min and about 60 psi for about 15minutes, Both cleaning solutions are recirculated back in to the CIP supply tank. The cycleis repeated until a desired level of cleanliness is achieved. It is pated that the total cleaning time (the total duration of the plurality of cleaning cycles) is less than 10 hours, as ed to the typical 12-18 hours using a conventional CIP method.

In other embodiments, the ?rst ng Solution (A) is applied for at least 20 s, 30 s, 40 s, 50 s, 60 s, 90 s, 2 min, 2 min 30 s, 3 min, 4 min, or 5 min or , and/or no more than 60 min, 30 min, 25 min, 20 min, 15 min, 10 min, 8 min, 7 min, 6 min, 5 min, 4 min, 3 min, 2 min 30 s, or 2 min. The ?rst cleaning solution (A) may be allowed to soak for 0 to about 5 min, or from 0 to about'3 min. The second cleaning solution (B) is applied for about 1 to 150 min, about 1 to 120 min, about 1 to 90 min, about 1 to 60 min, about 2 to 45 min, about 3 to 30 min, about 5 to 20 min, or about 10 to 18 min. The cleaning cycle (A +B) can be repeated any suitable number of times, such as 3 to 200 times, 5 to 150 times, 10 to 100 times, or 40—50 times.

In other embodiments, the ng method is used to clean other types of ent, such as other types of dryers, ovens, tanks, cooling towers, or conveyor belts.

The cleaning method was tested on dried milk powder soil. Solid cakes of test soil (75 g each) were prepared from skim milk powder in test trays by adding 5 % of water to the skim milk power and drying the mixture for 8 hours at 100 °C.

The test soils were treated in a pilot scale Clean—In-Place (CIP) chamber to simulate cleaning ions encountered in typical dairy product dryers.

The test sample was treated with a pretreatment solution ing solution "A") delivered via atomizing s for 10 minutes. Application through the atomizing nozzles simulated application through existing product delivery spray nozzles in a dryer. The pretreatment solution was d to penetrate and act for another 10 minutes before washing. The pretreatment composition is shown in TABLE 3A. The control did not receive a pretreatment.

TABLE 3A. Pretreatment Comosition (cleanin; solution "A") Concentrate Use Solution Com - onent (%) WI) Surfactant (DP-12) Both the test sample and control were washed simultaneously in the CIP chamber for 45 minutes with 1.5 % NaOH solution (cleaning solution "B") at 65 °C.

The trays were removed, rinsed, and weighed. The results are shown in TABLE 3B and FIGURE 4.

TABLE 3B. Soil Removal Soil Removed Sam 0 1e (-) Test (cleaning solution A +B) Control (cleaning solution B only) The results ed with the control matched those observed in real-world CIP of dairy dryer soils, which are typically very challenging to remove. It was observed that application of the pretreatment composition increased the soil removal ically as compared to the NaOH alone.

While certain ments of the invention have been bed, other embodiments may exist. While the speci?cation includes a detailed description, the invention’s scope is indicated by the following claims. The speci?c features and acts described above are disclosed as illustrative aspects and embodiments of the invention. s other aspects, embodiments, modi?cations, and equivalents thereof which, after reading the description herein, may suggest themselves to one of ordinary skill in the art t departing from the spirit of the present invention or the scope of the claimed subject matter.

I/

Claims (26)

WE CLAIM:

1. A method for cleaning product soil from equipment in place, the equipment comprising a first circuit comprising a product supply tank and one or more product s in fluid communication with the product supply tank, and a second circuit comprising a cleaning fluid supply tank and one or more cleaning nozzles in fluid communication with the cleaning fluid supply tank, wherein the first circuit and the second circuit are not the same, the method comprising: (a) draining a liquid t from a product supply tank in fluid communication with the one or more product nozzles in the equipment; (b) adding a first cleaning on to the product supply tank; (c) applying to the soil the first cleaning solution from the product supply tank through the one or more t nozzles; (d) adding a second cleaning solution to a cleaning fluid supply tank in fluid communication with one or more cleaning nozzles; (e) applying to the soil the second cleaning solution from the cleaning fluid supply tank through the one or more cleaning nozzles; (f) repeating step (c) and step (e) for two or more times; and (g) rinsing the equipment.

2. The method of claim 1, wherein the piece of equipment is selected from a dryer, a tank, a cooling tower, an oven, or a belt.

3. The method of any one of claims 1 or 2, wherein the piece of equipment is a spray dryer.

4. The method of any one of claims 1-3, wherein step (c) ses a first length of time, and step (e) comprises a second length of time that is longer than the first length of time.

5. The method of claim 4, wherein the first length of time is from about 20 s to about 10 min.

6. The method of claims 4 or 5, n the second length of time is from about 1 min to about 60 min.

7. The method of any one of claims 4-6, wherein the first length of time is about 30 s to about 5 min.

8. The method of any one of claims 4-7, wherein the second length of time is from about 5 min to about 20 min.

9. The method of any one of claims 1-8, wherein steps (c) and (e) are repeated from 5 to 150 cycles.

10. The method of any one of claims 1-9, wherein steps (c) and (e) are repeated from 10 to 100 cycles.

11. The method of any one of claims 1-10, wherein cleaning nozzles comprise a high pressure nozzle that applies the second cleaning solution to the equipment at a pressure of about 100 to about 500 psi.

12. The method of any one of claims 1-11, wherein the product nozzles consist of nonpressurized nozzles.

13. The method of any one of claims 1-12, wherein the first and second cleaning solutions are recirculated into the ng fluid supply tank.

14. The method of any one of claims 1-13, wherein the first and second cleaning solutions comprise active ingredients, and wherein the first cleaning on comprises active ients at a higher concentration than the second cleaning solution.

15. The method of claim 14, wherein the concentration of the active ingredients in the first cleaning solution is between about 4 and about 20 wt-%.

16. The method of claim 14, wherein the concentration of the active ingredients in the second cleaning solution is between about 0.1 and about 5 wt-%.

17. The method of any one of claims 1-16, wherein the first cleaning solution comprises agents that provide a soil disruption effect.

18. The method of any one of claims 1-17, n the first cleaning solution ses one or more peroxygen compounds.

19. The method of claim 18, wherein the gen compound is hydrogen de, a peroxycarboxylic acid, a persulfate, a perborate, a percarbonate, or a mixture thereof.

20. The method of any one of claims 1-19, wherein the first cleaning solution comprises an acid.

21. The method of any one of claims 1-20, wherein the first cleaning solution comprises a gas forming agent.

22. The method of claim 21, wherein the gas forming agent forms carbon dioxide or oxygen.

23. The method of any one of claims 1-22, wherein the second cleaning solution ses a metal hydroxide.

24. The method of any one of claims 1-23, wherein one or both of the first and second cleaning solutions comprise a surfactant.

25. The method of any one of claims 1-24, n one or both of the first and second cleaning solutions comprise a builder.

26. The method of any one of claims 1-25, wherein one or both of the first and second cleaning solutions comprise a solvent. Ecolab USA Inc. By the Attorneys for the Applicant SPRUSON & FERGUSON 1 / 6