A method for degreasing the inner surface of a purification device

Abstract

This invention relates to the field of degreasing technology and discloses a method for degreasing the inner surface of a purification device, comprising the following steps: S1, degreasing the inner surface of the inner cylinder with hot water; S2, degreasing again with an organic solvent; S3, detecting the residual esterification on the inner wall of the degreased inner cylinder; S4, cleaning the inner wall again with an alkaline substance; S5, after rinsing with the alkaline substance, neutralizing the alkaline substance with a weak acidic substance and cleaning the residual esterification; S6, detecting the residual esterification in the scratches, corners, and joints of the inner wall of the rinsed inner cylinder. This invention, based on the difference between the free acidity of the esterification on the inner wall before and after treatment, the difference between the moisture content of the esterification on the inner wall before and after treatment, and the proportion of residual alcohol, can quickly and efficiently determine whether the initial degreasing of the inner surface of the purification device is qualified.

Description

Technical Field

[0001] This invention relates to the field of degreasing technology, and in particular to a method for degreasing the inner surface of a purification device. Background Technology

[0002] Degreasing methods refer to the process of removing fats or oils from substances through physical, chemical, or biological means. Purification equipment is used to separate and remove unwanted impurities from mixtures to obtain pure substances; common purification equipment includes distillation and filtration devices. After prolonged use, these devices often accumulate and adhere esterified substances on the inner walls of their inner cylinders.

[0003] An existing patent (CN110722008A) discloses a device and method for degreasing and pre-degreasing the outer surface of cold-rolled seamless stainless steel tubes. During the cold rolling process, an external degreasing and pre-degreasing component installed on the exit side of the seamless stainless steel cold rolling mill completes the degreasing and pre-degreasing functions on the outer surface of the stainless steel tube. Simultaneously, oil scraping and air blowing are used to degrease the inner surface of the stainless steel tube. The degreasing and pre-degreasing process employs pneumatic and automatic control. However, the technology disclosed in this patent lacks specific inspection indicators for ester removal. This leads to significant subjective judgment among different operators regarding whether the equipment has completely removed esters, resulting in a substantial risk of rework. Summary of the Invention

[0004] The main technical problem solved by this invention is to provide a method for degreasing the inner surface of a purification device, thereby solving the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, according to one aspect of the present invention, more specifically, a method for degreasing the inner surface of a purification device, comprising the following steps:

[0006] S1. Use hot water to degrease the inner surface of the inner cylinder;

[0007] S2. Degrease again using organic solvents;

[0008] S3. Detect the residual esterification on the inner wall of the degreased inner cylinder;

[0009] S4. Clean the inner wall again with an alkaline substance;

[0010] S5. After rinsing off the alkaline substances, neutralize them with a weak acid and clean off any remaining esters.

[0011] S6. After rinsing, test the residual ester content in the scratches, corners, and joints of the inner wall of the inner cylinder.

[0012] Furthermore, in step S1, the inner cylinder is immersed in hot water at 60℃-80℃, and it is observed whether there is obvious grease shedding.

[0013] When obvious grease loss occurs, proceed to step S2; if no obvious grease loss occurs, continue soaking.

[0014] Furthermore, in step S2, after the inner cylinder is dried after being cleaned with hot water, it is cleaned again with the organic solvent ethanol, and the inner surface after cleaning is observed to see if there are any obvious scars.

[0015] When there are obvious scars on the inner surface of the inner cylinder, extract a sample of the scar and test the ester residue of the scar. If the ester residue test fails, step S2 needs to be repeated.

[0016] Once the inner surface of the inner cylinder has no obvious scars or the scars have passed the ester residue test, the inner surface of the inner cylinder should be rinsed again with hot water at 60℃-80℃.

[0017] Furthermore, in step S3, the residual esterification on the inner wall of the degreased inner cylinder is detected. The pass / fail status is determined based on the difference between the free acidity of the esterification before and after treatment, the difference between the moisture content of the esterification before and after treatment, and the percentage of residual alcohol.

[0018]

[0019] In the formula, C represents the pass coefficient for the initial ester residue test of the inner wall of the inner cylinder, a represents the difference between the free acidity of the esters on the inner wall before treatment and the free acidity of the esters on the inner wall after treatment, m represents the difference between the moisture content of the esters on the inner wall before treatment and the moisture content of the esters on the inner wall after treatment, and s1 represents the proportion of residual alcohol in 1 gram of sample.

[0020] When C < 83%, it indicates that the inner wall of the inner cylinder fails the initial ester residue test.

[0021] When C ≥ 83%, it indicates that the inner wall of the inner cylinder has passed the initial esterification residue test.

[0022] Furthermore, in step S4, after drying the inner surface of the inner cylinder, the inner wall is cleaned again with sodium hydroxide, and it is observed whether foam is generated.

[0023] When obvious foam is generated, proceed to step S5 to rinse the inner surface of the inner cylinder with a weak acidic substance.

[0024] If no foam is generated, proceed directly to step S6.

[0025] Furthermore, in step S6, the inner wall of the inner cylinder is checked for scratches and whether there is any residue buildup at the corners, in order to determine whether it is necessary to test the residual amount of esterified compounds.

[0026] If there is obvious accumulated residue, the residue needs to be tested for the amount of esterified material. If the test for the amount of esterified material fails, the process needs to be restarted in step S5.

[0027] When there are no accumulated residues on the inner wall scratches or corners, or when the residues pass the test for residual esterification, it indicates that the degreasing of the inner surface of the inner cylinder is complete.

[0028] Furthermore, in step S6, the residue is tested for the remaining esters. Based on the difference between the saponification value of the inner wall esters before and after treatment, the percentage of esters in 1 gram of sample, and the percentage of fatty acids in 1 gram of sample, the determination is made whether the remaining ester test of the residue is qualified. Therefore:

[0029]

[0030] In the formula, H represents the pass coefficient for the secondary ester residue test of the inner wall of the inner cylinder, k represents the difference between the saponification value of the inner wall ester before treatment and the saponification value of the inner wall ester after treatment, s2 represents the proportion of esters contained in 1 gram of sample, and u represents the proportion of fatty acids in 1 gram of sample.

[0031] When H≥80%, it indicates that the second ester residue test of the inner wall of the inner cylinder is qualified;

[0032] When H < 80%, it indicates that the secondary esterification residue test on the inner wall of the inner cylinder is unqualified.

[0033] Beneficial effects:

[0034] 1. Based on the difference between the free acidity of the inner wall esterified material before and after treatment, the difference between the moisture content of the inner wall esterified material before and after treatment, and the proportion of residual alcohol, this invention can quickly determine whether the initial degreasing of the inner surface of the purification device is qualified.

[0035] 2. Based on the difference between the saponification value of the inner wall esterification before and after treatment, the proportion of esters in the sample, and the proportion of fatty acids in the sample, this invention can quickly and efficiently determine whether the esterification of the residue exceeds the standard after defatting. Attached Figure Description

[0036] Figure 1 This is a flowchart of the present invention;

[0037] Figure 2A schematic diagram illustrating the model relationship between C and s1 and a under the state of control variable m;

[0038] Figure 3 This is a schematic diagram illustrating the model relationship between H, k, and u under the state of control variable s2. Detailed Implementation

[0039] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Example 1

[0041] like Figure 1 As shown, according to one aspect of the present invention, a method for degreasing the inner surface of a purification device is provided, comprising the following steps:

[0042] Step 1: Degrease the inner surface of the inner cylinder using hot water.

[0043] Soak the inner cylinder in hot water at 60℃-80℃ and observe whether there is obvious grease shedding. If there is obvious grease shedding, proceed to step one. If there is no obvious grease shedding, continue soaking.

[0044] Step 2: Degrease again using organic solvents:

[0045] After drying the inner cylinder after hot water washing, clean it again with the organic solvent ethanol and observe whether there are obvious scars on the inner surface after cleaning. If there are obvious scars on the inner surface of the inner cylinder, extract a sample of the scar and test the residual ester content of the scar. If the residual ester content test fails, step two needs to be repeated. If there are no obvious scars on the inner surface of the inner cylinder or the residual ester content test of the scar passes, the inner surface of the inner cylinder needs to be rinsed again with hot water at 60℃-80℃.

[0046] Step 3: Detect the residual esterification on the inner wall of the degreased inner cylinder;

[0047] Step 4: Clean the inner wall again using an alkaline substance:

[0048] In step four, after drying the inner surface of the inner cylinder, the inner wall is cleaned again with sodium hydroxide, and it is observed whether foam is generated. When obvious foam is generated, proceed to step five and rinse the inner surface of the inner cylinder with a weak acidic substance. When no foam is generated, proceed directly to step six.

[0049] Step 5: After rinsing off the alkaline substances, neutralize them with a weak acid and wash away any remaining esters.

[0050] Step Six: After rinsing, test the residue in the scratches, corners, and joints of the inner wall of the inner cylinder for residual esters.

[0051] In step six, check whether there is any residue buildup on the scratches and corners of the inner wall of the inner cylinder to determine whether it is necessary to test the residual ester content. If there is obvious residue buildup, it is necessary to test the residual ester content. If the residual ester content test fails, it is necessary to repeat step five. When there is no residue buildup on the scratches and corners of the inner wall or the residual ester content test is qualified, it means that the degreasing of the inner surface of the inner cylinder is complete.

[0052] Example 2

[0053] like Figure 2 As shown, the residual esterification on the inner wall of the degreased inner cylinder is tested. The pass / fail status is determined based on the difference between the free acidity of the esterification before and after treatment, the difference between the moisture content of the esterification before and after treatment, and the percentage of residual alcohol.

[0054]

[0055] In the formula, C represents the pass coefficient for the initial ester residue test of the inner wall of the inner cylinder, a represents the difference between the free acidity of the esters on the inner wall before treatment and the free acidity of the esters on the inner wall after treatment, m represents the difference between the moisture content of the esters on the inner wall before treatment and the moisture content of the esters on the inner wall after treatment, and s1 represents the proportion of residual alcohol in 1 gram of sample.

[0056] When C < 83%, it indicates that the inner wall of the inner cylinder fails the initial ester residue test.

[0057] When C ≥ 83%, it indicates that the inner wall of the inner cylinder has passed the initial esterification residue test.

[0058] Among them, sample X, which is undergoing the initial ester residue detection, is tested. The difference between the free acidity of the inner wall ester before treatment and the free acidity of the inner wall ester after treatment is taken as a = 0.4 (%, free acidity = (volume of detection solution consumed (mL) × concentration of detection solution (mol / L) × molecular weight of free fatty acid (g / mol)) ÷ mass of sample (g) × 100).

[0059] The difference between the moisture content of the esterified material on the inner wall before and after treatment is taken as m = 0.2 (%). The percentage of residual alcohol in 1 gram of sample is taken as s1 = 0.1 (%), then:

[0060]

[0061] From the above calculations, it can be seen that after the initial ester residue test of sample X, the pass rate for the ester residue test is C = 83.4%, therefore, the inner wall of the inner cylinder passes the initial ester residue test. Furthermore, comparing multiple sets of data, we have:

[0062]

[0063] The data above shows that when the implemented data approaches infinity, a clear dividing line between acceptable and unacceptable results will appear. This dividing line is 83%.

[0064] When C < 83%, it indicates that the inner wall of the inner cylinder fails the initial ester residue test; when C ≥ 83%, it indicates that the inner wall of the inner cylinder passes the initial ester residue test.

[0065] Example 2

[0066] like Figure 3 As shown, the residue is tested for the remaining esters. The quality is determined based on the difference between the saponification values ​​of the inner wall esters before and after treatment, the percentage of esters in 1 gram of sample, and the percentage of fatty acids in 1 gram of sample. Therefore:

[0067]

[0068] In the formula, H represents the pass coefficient for the secondary ester residue test of the inner wall of the inner cylinder, k represents the difference between the saponification value of the inner wall ester before treatment and the saponification value of the inner wall ester after treatment, s2 represents the proportion of esters contained in 1 gram of sample, and u represents the proportion of fatty acids in 1 gram of sample.

[0069] When H≥80%, it indicates that the second ester residue test of the inner wall of the inner cylinder is qualified;

[0070] When H < 80%, it indicates that the secondary esterification residue test on the inner wall of the inner cylinder is unqualified.

[0071] The difference between the saponification value of the inner wall esterification before treatment and the saponification value of the inner wall esterification after treatment is taken as k = 43 (unit: mg KOH / g, saponification value = (volume consumed by the detection solution (mL) × concentration of the detection solution (mol / L) × 56.1) ÷ mass of the sample (g)).

[0072] If the percentage of esters in 1 gram of sample is s² = 0.083%, and the percentage of fatty acids in 1 gram of sample is u = 0.1%, then:

[0073]

[0074] From the above calculations, it can be seen that after the sample underwent a second ester residue test, the pass rate for the ester residue test was H = 75.01%, therefore, the inner wall of the inner cylinder passed the second ester residue test. Furthermore, comparing multiple sets of data, we have:

[0075]

[0076] The data above shows that when the implemented data approaches infinity, a clear dividing line between acceptable and unacceptable results will appear. This dividing line is 80%.

[0077] When H ≥ 80%, it indicates that the second ester residue test of the inner wall of the inner cylinder is qualified; when H < 80%, it indicates that the second ester residue test of the inner wall of the inner cylinder is unqualified.

[0078] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for degreasing the inner surface of a purification device, characterized in that, It includes the following steps: S1. Degrease the inner surface of the inner cylinder with hot water; S2. Degrease again with the organic solvent ethanol; S3. Detect the residual amount of esterified substances on the inner wall of the degreased inner cylinder; S4. Clean the inner wall again with an alkaline substance; S5. After rinsing the alkaline substance, neutralize the alkaline substance with a weak acidic substance and clean the residual esterified substances; S6. Detect the residual amount of esterified substances in the residues in the scratches, corners and accumulations at the joints on the inner wall of the inner cylinder after rinsing; Among them, in step S3, when detecting the residual amount of esterified substances on the inner wall of the degreased inner cylinder, it is determined whether the detection is qualified according to the difference between the free acidity of the esterified substances on the inner wall before treatment and the free acidity of the esterified substances on the inner wall after treatment, the difference between the moisture content of the esterified substances on the inner wall before treatment and the moisture content of the esterified substances on the inner wall after treatment, and the proportion of residual alcohol. There is: In the formula, This indicates the pass rate for the initial ester residue test of the inner wall of the inner cylinder. This represents the difference between the free acidity of the esterified material on the inner wall before treatment and the free acidity of the esterified material on the inner wall after treatment. This represents the difference between the moisture content of the esterified material on the inner wall before treatment and the moisture content of the esterified material on the inner wall after treatment. This indicates the percentage of residual ethanol in 1 gram of sample. when If the result is negative, it indicates that the initial ester residue test of the inner wall of the inner cylinder is unqualified. when If the result is positive, it indicates that the inner wall of the inner cylinder has passed the initial esterification residue test.

2. The method for degreasing the inner surface of the purification device according to claim 1, characterized in that: In step S1, place the inner cylinder in hot water at 60°C - 80°C and soak it, and observe whether obvious oil shedding occurs; When obvious oil shedding occurs, enter step S2; when no obvious oil shedding occurs, continue to soak.

3. The method for degreasing the inner surface of the purification device according to claim 1, characterized in that: In step S2, after drying the inner cylinder cleaned with hot water, clean it with the organic solvent ethanol, and observe whether there are obvious scars on the cleaned inner surface; When there are obvious scars on the inner surface of the inner cylinder, extract a sample of the scars and detect the residual amount of esterified substances in the scars. When the detection of the residual amount of esterified substances is unqualified, step S2 needs to be repeated; When there are no obvious scars on the inner surface of the inner cylinder or the detection of the residual amount of esterified substances in the scars is qualified, the inner surface of the inner cylinder needs to be rinsed again with hot water at 60°C - 80°C.

4. The method for degreasing the inner surface of the purification device according to claim 1, characterized in that: In step S4, after drying the inner surface of the inner cylinder, clean the inner wall again with sodium hydroxide and observe whether foam is generated; When obvious foam is generated, enter step S5 and rinse the inner surface of the inner cylinder with a weak acidic substance; When no foam is generated, directly enter step S6.

5. The method for degreasing the inner surface of the purification device according to claim 1, characterized in that: In step S6, check whether there are residues accumulated at the scratches and corners on the inner wall of the inner cylinder to determine whether it is necessary to detect the residual amount of esterified substances in the residues; When there are obvious accumulated residues, it is necessary to detect the residual amount of esterified substances in the residues. When the detection of the residual amount of esterified substances is unqualified, it is necessary to re-enter step S5; When there are no residues accumulated at the scratches and corners on the inner wall or the detection of the residual amount of esterified substances in the residues is qualified, it means that the degreasing of the inner surface of the inner cylinder is completed.

6. The method for degreasing the inner surface of the purification device according to claim 1, characterized in that: In step S6, when detecting the residual amount of esterified substances in the residues, it is determined whether the detection of the residual amount of esterified substances in the residues is qualified according to the difference between the saponification value of the esterified substances on the inner wall before treatment and the saponification value of the esterified substances on the inner wall after treatment, the proportion of esters contained in 1 gram of the sample, and the proportion of fatty acids in 1 gram of the sample. Then there is: In the formula, This indicates the pass rate for the secondary ester residue test on the inner wall of the inner cylinder. This represents the difference between the saponification value of the esterified material on the inner wall before treatment and the saponification value of the esterified material on the inner wall after treatment. This indicates the percentage of esters contained in 1 gram of sample. This indicates the percentage of fatty acids in 1 gram of sample; when If the result is 1, it indicates that the second ester residue test on the inner wall of the inner cylinder is qualified. when If the result is negative, it indicates that the second test for the remaining esterified material on the inner wall of the inner cylinder failed.

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