JPS6250199B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for removing scale that adheres to the inner wall of a fermentation apparatus during the beer manufacturing process by dissolving the scale that adheres to the inner wall of the fermentation apparatus. Conventionally, when producing beer,
A liquid, so-called wort, containing soluble fermentable sugars is first made by heating ground malt with water, with or without the addition of starchy auxiliary materials. Next, hops are added to this wort and boiled, or after treatment with extracts from hops, or without any of these treatments, yeast is added to the wort at an appropriate temperature in a fermentation tank, and the fermentable sugars are converted to alcohol or carbonic acid. Conversion to gas and fermentation by-products takes place. This step is called pre-fermentation, and the resulting fermented liquor is usually called young beer. After separating the yeast, young beer is produced by further post-fermentation in a post-fermentation tank.
It removes the smell of young beer, removes beer proteins, and dissolves carbon dioxide into the beer. The beer obtained by post-fermentation is subjected to a carbon dioxide gas treatment called carbonation, and then filtered to obtain a product. Insoluble substances gradually accumulate on the inner wall of the fermentation tank used in the pre-fermentation and post-fermentation steps, and eventually adhere as scale, which reduces heat transfer efficiency and also causes contamination with bacteria. Therefore, before charging cold wort etc. into the fermentation tank, the inner walls of the fermentation tank are usually descaled and sterilized, but it is particularly difficult to easily remove this scale, and normal cleaning methods are rarely effective. It cannot be removed well. Normally, a large number of fermentation tanks are installed in a fermentation room, and all of them are kept at a low temperature, for example, 10℃ or less, so any one tank, especially a large tank, is cleaned under high temperature heat. When doing so, it not only has an adverse effect on the surrounding tank, but also tends to cause deformation, which is undesirable. Therefore, cleaning is usually carried out at temperatures ranging from around 10°C to around room temperature, but at such low temperatures, scale may be removed by methods that use regular cleaning water or alkaline detergents containing caustic soda, caustic potash, etc. Almost never removed. In addition, periodic cleaning is performed using strong acids such as sulfuric acid, nitric acid, and urea nitrate, but the scale cannot be removed efficiently and may cause corrosion damage to the fermentation tank material. , undesirable. Furthermore, there are methods such as applying a paste made by mixing urea nitrate and diatomaceous earth onto the surface of the scale, or directly scraping off the scale with a metal brush, but these methods also have poor workability. Not liked. Usually, the tank material that the fermentation solution comes into contact with is:
Aluminum, gunmetal, SUS304, resin lining, etc., but solutions such as caustic soda and caustic potash are highly corrosive to aluminum, and solutions of nitric acid and urea nitrate are corrosive to gunmetal and generate nitrogen oxide. accompanied by Furthermore, nitric acid, sulfuric acid, and the like are powerful chemicals that are not easy to handle, and especially when sulfuric acid is used, by-product calcium sulfate may re-deposit, which may cause trouble. The inventors of the present invention aimed to establish a safe and efficient method for easily removing scale that adheres to the inner walls of beer fermentation equipment, and as a result of detailed research on the effects of various chemical solutions on the scale, we found that basic chloride Aqueous solutions of aluminum, basic aluminum nitrate, basic aluminum sulfamate, etc.
We have completed the present invention by discovering a surprising new fact that the scale described above can be dissolved extremely quickly at a low temperature of 10 to 20°C. The purpose of the present invention is to provide a method for easily, efficiently, and safely dissolving scale adhering to the inner walls of beer fermentation equipment.A further object of the present invention is to provide a method for easily, efficiently, and safely dissolving scale adhering to the inner walls of beer fermentation equipment. The object of the present invention is to provide a method for removing the above-mentioned scale that does not cause the scale to occur. The scale removal method of the present invention uses chloride ions, nitrate radicals,
Contacting an aqueous solution in which one or more anions selected from the group consisting of sulfamic acid radicals and aluminum ions are made to coexist at a ratio of 0.33 mol or more and less than 3 mol of the above anions per 1 mol of aluminum ions. It is characterized by The scale to be dissolved and removed to which the method of the present invention is applied is the scale that adheres to the inner wall of the equipment that comes into contact with the fermentation liquid in the pre-fermentation and post-fermentation steps in beer production, and its main components are calcium and oxalic acid. It is. The aqueous solution used in the present invention contains chloride ions, nitrate radicals, sulfamic acid radicals, etc. and aluminum ions in water, and the above anions are preferably 0.33 mol or more and less than 3 mol, particularly preferably 1 to 2.5 mol, per 1 mol of aluminum ions. Any other optional components may be contained as long as they coexist in the same proportions and the object of the present invention is achieved. For molar ratios outside the range of the above ratios,
Aqueous solutions are not preferred because they have a reduced ability to dissolve scale. The aqueous solution used in the present invention in which both of the ions coexist in the above molar ratio can be prepared by, for example, dissolving basic aluminum chloride, basic aluminum nitrate, basic aluminum sulfamate, etc. in water, or by dissolving hydrochloric acid, nitric acid, It can be easily obtained by dissolving sulfamic acid etc. and aluminum hydroxide or metal aluminum in water, and generally the ionic composition in the liquid is a basic salt Al(X) _o
(OH) _3-o (However, X is a chlorine ion, an anion group of nitric acid, or an anion of sulfamic acid, and n
represents a number from 0.33 to less than 3. ) can be obtained by dissolving a soluble substance in water so that it has the following composition. The aqueous solution used in the present invention contains chloride ions, nitrate radicals, or sulfamic acid radicals, and aluminum ions, but when dissolving the scale, it is necessary to use the anions and aluminum in sufficient amounts to dissolve the entire scale. must be included. The preferred amount of aqueous solution to be contacted with the scale depends on the aluminum ion content and the concentration of the anion. If the concentration of the aqueous solution is too high, the dissolving ability will not be improved accordingly, and if the concentration is too low, the time for which the aqueous solution should be in contact with the scale will be undesirable. The generally preferred concentration range is about 0.001 to 12.4% by weight, particularly about 0.01 to 6% by weight of aluminum ions. Further, the preferred concentration and amount of the aqueous solution used to remove the attached scale also depend on the conditions for contacting the solution with the scale. Usually, the chemical composition of the scale to be removed is not constant, but it is preferable that the above aqueous solution is brought into contact with the scale at a ratio of 10 to 10,000 parts by weight per 1 part by weight of the scale. According to the method of the present invention, the temperature of the aqueous solution when it is brought into contact with the scale is usually 0 to 80°C, preferably 5 to 40°C,
Particularly preferably, the temperature is about 10 to 25°C. In order to quickly dissolve the scale according to the method of the present invention, the aqueous solution may be brought into contact with the scale by spraying using a cleaning device in place, or the aqueous solution may be supplied into the fermentation device and the stored liquid may be stirred. Another method is to contact the The aqueous solution used in the present invention may include surfactants, alcohols, acids, esters, salts, corrosion inhibitors, etc., as long as the purpose of the present invention is achieved, in addition to the specific ions in the specific ratio. There is no problem even if a bactericide or the like is included. Further, the method of the present invention
It can also be carried out in combination with a conventional cleaning method using an alkaline aqueous solution and a sterilizing detergent, a cleaning method by bringing an acidic aqueous solution into contact with the scale, and the like. In addition, slurry obtained by further blending diatomaceous earth, other carriers, abrasives, etc.
Scale removal can also be carried out by contacting or applying a paste or the like to the scale surface. Next, preferred embodiments of the present invention will be illustrated. (1) Basic aluminum chloride, basic aluminum nitrate, basic aluminum sulfamate, or a mixture thereof, in a molar ratio of 1 to 2.5 moles of acid anion per 1 mole of aluminum ion, and 0.01 mole as aluminum ion. ~4
An aqueous solution obtained by dissolving in water in a proportion of % by weight is applied to a scale that is attached to the inner wall of the fermentation equipment.
Method of contact at 2-25℃. (2) Hydrochloric acid, nitric acid, sulfamic acid, or a mixture thereof and aluminum hydroxide in a molar ratio of 1 to 2 moles of anion of the above acid per mole of aluminum ion, and as aluminum ion.
The method of (1) above, wherein an aqueous solution obtained by dissolving in water at a ratio of 0.01 to 4% by weight is used instead of the aqueous solution in (1) above. The method of the present invention is used to dissolve and remove scale adhering to the inner wall of a fermentation apparatus in the beer manufacturing process, and the scale is mainly composed of calcium and oxalic acid, and also contains small amounts of other organic and inorganic substances. Since these main components are extremely well dissolved by the aqueous solution used in the present invention, it is thought that the tissue structure forming the scale is easily dissolved. The method of the present invention includes:
Extremely useful. The present invention will be described in more detail below with reference to Examples, but the technical scope of the present invention is not limited thereto. Example 1 1.00 g of scale (A) to be attached to the inner wall of a fermentation tank in a beer brewing factory was added to 100 g of the chemical solution listed in Table 1, and after stirring at 20°C for the time listed in the table, 0.6
The scale dissolution rate was determined by passing through a μ Millipore filter and weighing the excess residue. The above chemical solution was obtained by reacting and dissolving metallic aluminum and sulfamic acid in water so as to have the composition and concentration as shown in Experiment Nos. 1 to 3 in Table 1. The results are shown in Table 1.

[Table] Example 2 Same scale as used in Example 1 (A) 0.5g
was poured into 50 g of a 5% aqueous basic aluminum chloride solution, stirred at 20°C for 2 hours, and undissolved matter was separated using a 0.6μ Millipore filter to determine the scale dissolution rate. The results are shown in Table 1, Experiment No. 4. Example 3 Same scale as used in Example 1 (A) 0.5g
was poured into 50 g of a basic aqueous aluminum nitrate solution, stirred at 20° C. for 2 hours, and undissolved components were separated using a 0.6μ Millipore filter to determine the dissolution rate. The results are shown in Table 1, Experiment No. 5. Example 4 0.5 g of another scale (B) to be attached to the inner wall of a fermentation tank in a beer brewing factory was put into 50 g of a 5% basic aluminum sulfamate aqueous solution, stirred for 2 hours at the temperature listed in Table 1, and then, Undissolved matter was separated using a 0.6μ Millipore filter, and the dissolution rate was determined. The results are shown in Table 1, Experiment Nos. 6 and 7. Separately, a corrosion test was conducted on the following material test pieces for the aqueous solution used in the present invention and the aqueous solution for comparison. Test piece A: Aluminum plate (JIS H4000, #320
Polished finish), thickness, vertical and horizontal dimensions are 1 mm, 12 mm and 75 mm, respectively, and are degreased and cleaned with acetone. Test piece B: Gunmetal plate (JIS H5111, #320 polished finish), thickness, vertical and horizontal dimensions each 3 mm,
12mm and 75mm, and can be degreased and cleaned with acetone. Test piece C: SUS304 steel plate (JIS G4305, #320 polished finish), dimensions and cleaning treatment are the same as test piece A. Three test pieces A, three test pieces B, and three test pieces C were placed in nine 120 ml glass containers, and 110 g of the aqueous solution listed in Table 2 was added to the test pieces A,
They were individually placed in containers B and C, left completely immersed at 20°C for 6 hours, then taken out, washed with running water, washed with acetone, dried and weighed to calculate the weight loss.Table 2 The results shown are obtained.

[Table] As shown in Table 2, an aqueous solution of caustic soda greatly corrodes aluminum plates, and urea nitrate is corrosive to gunmetal. On the other hand, it was confirmed that the aqueous solution used in the present invention has low corrosiveness to any of the above-mentioned materials, and can be sufficiently put to practical use.

Claims (1)

[Claims] 1. One or more anions selected from the group consisting of chloride ions, nitrate radicals, and sulfamic acid radicals and aluminum ions are added to the scale attached to the inner wall of fermentation equipment in the beer manufacturing process. The method for removing scale as described above, comprising contacting with an aqueous solution in which the above-mentioned anions coexist at a ratio of 0.33 mol or more and less than 3 mol per 1 mol. 2. The method for removing scale according to claim 1, wherein the aqueous solution contains 0.001 to 12.4% by weight of aluminum. 3 The temperature of the aqueous solution in contact with the scale is 0 to 50
The method for removing scale according to claim 1 or 2, wherein the temperature is .degree. 4. Claim 1, wherein the aqueous solution is prepared by dissolving basic aluminum chloride, basic aluminum nitrate, basic aluminum sulfamate, or a mixture thereof in water.
The method for removing scale according to item 2, item 3, or item 3. 5. The scale according to claim 1, 2 or 3, wherein the aqueous solution is prepared by dissolving hydrochloric acid, nitric acid, sulfamic acid or a mixture thereof and aluminum hydroxide in water. Removal method.