Degreasing method for inner surface of purification device

Abstract

The invention relates to the technical field of degreasing processes, and discloses a purification device inner surface degreasing method which comprises the following steps: S1, degreasing the inner surface of an inner cylinder by using hot water; s2, degreasing again by using an organic solvent; s3, performing ester residue detection on the inner wall of the degreased inner cylinder; s4, cleaning the inner wall again by using an alkaline substance; s5, flushing the alkaline substance, neutralizing the alkaline substance by using a weakly acidic substance, and cleaning residual ester; and S6, residues in deposits at scratches, corners and joints of the inner wall of the flushed inner cylinder are subjected to ester residue detection. According to the difference between the free acidity of the inner wall ester before treatment and the free acidity of the inner wall ester after treatment, the difference between the moisture content of the inner wall ester before treatment and the moisture content of the inner wall ester after treatment and the proportion of residual alcohol, whether primary degreasing of the inner surface of the purification device is qualified or not can be quickly and efficiently judged.

Description

Technical Field

[0001] The invention relates to the technical field of degreasing processes, and in particular to a method for degreasing the inner surface of a purification device. Background Art

[0002] Degreasing refers to the process of removing fat or grease from a substance by physical, chemical or biological means. Purification devices are used to separate and remove unwanted impurities from a mixture to obtain pure substances. Common purification devices are distillation devices and filtration devices. After long-term use, these devices often have esterification products accumulated and attached to the inner wall of the inner cylinder.

[0003] The existing patent discloses a cold-rolled seamless stainless steel pipe degreasing and outer surface pre-degreasing device and method (CN110722008A). During the discharge process of the cold-rolling process of the stainless steel pipe, the cold-rolled seamless stainless steel pipe outer degreasing and degreasing components installed on the outlet side of the seamless stainless steel cold rolling mill are used to complete the degreasing and pre-degreasing functions of the outer surface of the stainless steel pipe, and the oil scraping and air blowing methods are used to complete the degreasing function of the inner surface of the stainless steel pipe; the degreasing and pre-degreasing process adopts pneumatic and automatic control modes. The technology disclosed in this patent lacks specific inspection indicators for the removal of esterification products, which results in a large number of subjective judgment factors when different staff members judge whether the equipment has removed esterification products cleanly, which also makes there a great risk of rework in the future. Summary of the invention

[0004] The main technical problem solved by the present invention is to provide a method for degreasing the inner surface of a purification device, which solves the problems in the above-mentioned background technology.

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

[0006] S1. Degrease the inner surface of the inner cylinder using hot water;

[0007] S2, degreasing again using an organic solvent;

[0008] S3, detecting the esterification residue on the inner wall of the inner cylinder after degreasing;

[0009] S4. Use alkaline substances to clean the inner wall again;

[0010] S5, after rinsing the alkaline substance, neutralize the alkaline substance with a weak acidic substance, and wash the residual esterification product;

[0011] S6. After flushing, the residual ester residue in the scratches on the inner wall of the inner cylinder, the deposits at the corners and joints is tested.

[0012] Furthermore, in step S1, the inner cylinder is immersed in hot water at 60°C-80°C, and whether obvious grease shedding occurs;

[0013] When obvious grease shedding occurs, the process proceeds to step S2; when no obvious grease shedding occurs, the process needs to continue soaking.

[0014] Furthermore, in step S2, the inner cylinder after being cleaned with hot water is dried, and then cleaned with organic solvent ethanol, and the inner surface after cleaning is observed to see whether there is an obvious scar;

[0015] When there is an obvious scar on the inner surface of the inner cylinder, extract a sample of the scar and perform an esterification residue test on the scar. If the esterification residue test fails, step S2 needs to be repeated;

[0016] When there is no obvious scar on the inner surface of the inner cylinder or the scar passes the esterification residue test, the inner surface of the inner cylinder needs to be rinsed again with hot water at 60℃-80℃.

[0017] Furthermore, in step S3, the inner wall of the inner cylinder after degreasing is tested for esterification residue, and whether the test is qualified is determined according to the difference between the free acidity of the esterification of the inner wall before treatment and the free acidity of the esterification of the inner wall after treatment, the difference between the moisture content of the esterification of the inner wall before treatment and the moisture content of the esterification of the inner wall after treatment, and the proportion of residual alcohol, which are:

[0018]

[0019] In the formula, C represents the qualified coefficient of the initial esterification residue detection of the inner wall of the inner cylinder, a represents the difference between the free acidity of the esterification of the inner wall before treatment and the free acidity of the esterification of the inner wall after treatment, m represents the difference between the moisture content of the esterification of the inner wall before treatment and the moisture content of the esterification of the inner wall after treatment, and s1 represents the proportion of residual alcohol in 1 gram of sample;

[0020] When C < 83%, it means that the inner wall of the inner cylinder fails the initial esterification residue test;

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

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

[0023] When foam is obviously generated, the process proceeds to step S5 to rinse the inner surface of the inner cylinder with a weak acidic substance;

[0024] When no foam is generated, the process directly proceeds to step S6.

[0025] Furthermore, in step S6, the inner wall scratches of the inner cylinder and whether residues are accumulated at the corners are checked to determine whether the residues need to be tested for esterification residues;

[0026] When there is obvious accumulation of residues, it is necessary to perform an esterification residue detection on the residues. If the esterification residue detection fails, it is necessary to re-enter step S5;

[0027] When there is no accumulation of residues on the inner wall scratches and corners, or the esterification residue is tested to be qualified, it means that the inner surface of the inner cylinder is degreased.

[0028] Furthermore, in step S6, the residue is tested for the residual amount of esterification, and the difference between the saponification value of the inner wall esterification before treatment and the saponification value of the inner wall esterification after treatment, the proportion of esters contained in 1 gram of sample, and the proportion of fatty acids in 1 gram of sample are used to determine whether the residual amount of esterification of the residue is qualified. Then:

[0029]

[0030] In the formula, H represents the qualified coefficient of the secondary esterification residue detection of the inner wall of the inner cylinder, k represents the difference between the saponification value of the esterification of the inner wall before treatment and the saponification value of the esterification of the inner wall 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 means that the inner wall of the inner cylinder has passed the secondary esterification residue test;

[0032] When H is less than 80%, it means that the secondary esterification residue detection on the inner wall of the inner cylinder is unqualified.

[0033] Beneficial effects:

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

[0035] 2. The present invention can quickly and efficiently determine whether the esterification of the residue after degreasing exceeds the standard based on the difference between the saponification value of the inner wall esterification before treatment and the saponification value of the inner wall esterification after treatment, the proportion of esters contained in the sample and the proportion of fatty acids in the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a flow chart of the present invention;

[0037] Figure 2It is a schematic diagram of the model relationship between C, s1 and a under the state of controlling variable m;

[0038] Figure 3 Schematic diagram of the model relationship between H, k and u under the state of control variable s2. DETAILED DESCRIPTION

[0039] In order to make the technical solution of the present invention clearer, the present invention is 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: Use hot water to degrease the inner surface of the inner cylinder:

[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 1. If there is no obvious grease shedding, continue soaking.

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

[0045] After drying the inner cylinder after washing with hot water, use organic solvent ethanol to wash it again, and observe whether there are obvious scars on the inner surface after washing; when there are obvious scars on the inner surface of the inner cylinder, extract the scar sample and perform ester residue test on the scar. When the ester residue test fails, repeat step 2; when there are no obvious scars on the inner surface of the inner cylinder or the ester residue test on the scar passes, rinse the inner surface of the inner cylinder again with hot water at 60℃-80℃.

[0046] Step 3, detecting the esterification residue on the inner wall of the inner cylinder after degreasing;

[0047] Step 4: Use alkaline substances to clean the inner wall again:

[0048] In step 4, after drying the inner surface of the inner cylinder, the inner wall is cleaned again with sodium hydroxide to observe whether foam is generated; when foam is obviously generated, proceed to step 5 to rinse the inner surface of the inner cylinder with a weak acidic substance; when no foam is generated, proceed directly to step 6.

[0049] Step 5: After rinsing the alkaline substance, use a weak acidic substance to neutralize the alkaline substance and wash the residual esterification product;

[0050] Step 6: Detect the ester residue in the scratches, corners and joints of the inner cylinder after flushing:

[0051] In step six, check whether there are residues accumulated on the scratches on the inner wall of the inner cylinder and at the corners to determine whether it is necessary to perform an esterification residue detection on the residues; when there are obvious accumulated residues, it is necessary to perform an esterification residue detection on the residues. When the esterification residue detection fails, it is necessary to re-enter step five; when there are no accumulated residues on the scratches on the inner wall and at the corners or the esterification residue detection on the residue passes, it indicates that the inner surface of the inner cylinder is degreased.

[0052] Example 2

[0053] like Figure 2 As shown, the inner wall of the inner cylinder after degreasing is tested for ester residue. Whether the test is qualified is determined based on the difference between the free acidity of the esterified inner wall before treatment and the free acidity of the esterified inner wall after treatment, the difference between the moisture content of the esterified inner wall before treatment and the moisture content of the esterified inner wall after treatment, and the proportion of residual alcohol. There are:

[0054]

[0055] In the formula, C represents the qualified coefficient of the initial esterification residue detection of the inner wall of the inner cylinder, a represents the difference between the free acidity of the esterification of the inner wall before treatment and the free acidity of the esterification of the inner wall after treatment, m represents the difference between the moisture content of the esterification of the inner wall before treatment and the moisture content of the esterification of the inner wall after treatment, and s1 represents the proportion of residual alcohol in 1 gram of sample;

[0056] When C < 83%, it means that the inner wall of the inner cylinder fails the initial esterification residue test;

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

[0058] Among them, the sample X that was tested for the first time for the esterification residue detection was tested. The difference between the free acidity of the inner wall esterification before treatment and the free acidity of the inner wall esterification after treatment was a=0.4(%, free acidity=(consumed detection solution volume (mL)×detection solution concentration (mol / L)×free fatty acid molecular weight (g / mol))÷sample mass (g)×100).

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

[0060]

[0061] From the above calculation, we can know that after the sample X that was tested for the first time for the esterification residue test was tested, the qualified coefficient of the esterification residue test was C=83.4%, so the inner wall of the inner cylinder passed the first esterification residue test. And comparing multiple groups of data, we have:

[0062]

[0063] From the above data, we can know that when the implementation data tends to infinity, there will be a clear qualified or unqualified dividing line, which is 83%.

[0064] When C is less than 83%, it indicates that the inner wall of the inner cylinder fails the initial esterification residue detection; when C is greater than or equal to 83%, it indicates that the inner wall of the inner cylinder passes the initial esterification residue detection.

[0065] Example 2

[0066] like Figure 3 As shown, the residue is tested for the residual amount of esterification. The difference between the saponification value of the inner wall esterification before treatment and the saponification value of the inner wall esterification after treatment, the proportion of esters contained in 1 gram of sample, and the proportion of fatty acids in 1 gram of sample are used to determine whether the residue is qualified for the residual amount of esterification. Then:

[0067]

[0068] In the formula, H represents the qualified coefficient of the secondary esterification residue detection of the inner wall of the inner cylinder, k represents the difference between the saponification value of the esterification of the inner wall before treatment and the saponification value of the esterification of the inner wall 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 means that the inner wall of the inner cylinder has passed the secondary esterification residue test;

[0070] When H is less than 80%, it means that the secondary esterification residue detection on the inner wall of the inner cylinder is unqualified.

[0071] Among them, 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 k = 43 (unit: mg KOH / g, saponification value = (consumption volume of detection solution (mL) × concentration of detection solution (mol / L) × 56.1) ÷ mass of sample (g)).

[0072] The proportion of ester in 1 gram of sample is s2 = 0.083 (%), and the proportion of fatty acid in 1 gram of sample is u = 0.1 (%), then:

[0073]

[0074] From the above calculation, we can know that after the sample with the second esterification residue detection is tested, the qualified coefficient of the esterification residue detection is H=75.01%, so the second esterification residue detection of the inner wall of the inner cylinder is qualified. And comparing multiple groups of data, we have:

[0075]

[0076] From the above data, we can know that when the implementation data tends to infinity, there will be a clear qualified or unqualified dividing line, which is 80%.

[0077] When H≥80%, it means that the secondary esterification residue detection of the inner wall of the inner cylinder is qualified; when H<80%, it means that the secondary esterification residue detection of the inner wall of the inner cylinder is unqualified.

[0078] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for degreasing the inner surface of a purification device, characterized in that: The following steps are involved: S1. Degrease the inner surface of the inner cylinder using hot water; S2, degreasing again using an organic solvent; S3, detecting the esterification residue on the inner wall of the inner cylinder after degreasing; S4. Use alkaline substances to clean the inner wall again; S5, after rinsing the alkaline substance, neutralize the alkaline substance with a weak acidic substance, and wash the residual esterification product; S6. After flushing, the residual ester residue in the scratches on the inner wall of the inner cylinder, the deposits at the corners and joints is tested.

2. The method for degreasing the inner surface of a purification device according to claim 1, characterized in that: In step S1, the inner cylinder is immersed in hot water at 60°C-80°C, and whether obvious grease shedding occurs; When obvious grease shedding occurs, the process proceeds to step S2; when no obvious grease shedding occurs, the process needs to continue soaking.

3. The method for degreasing the inner surface of a purification device according to claim 1, characterized in that: In step S2, the inner cylinder after washing with hot water is dried, and then washed with organic solvent ethanol, and the inner surface after washing is observed to see whether there is obvious scar; When there is an obvious scar on the inner surface of the inner cylinder, extract a sample of the scar and perform an esterification residue test on the scar. If the esterification residue test fails, step S2 needs to be repeated; When there is no obvious scar on the inner surface of the inner cylinder or the scar passes the esterification residue test, the inner surface of the inner cylinder needs to be rinsed again with hot water at 60℃-80℃.

4. The method for degreasing the inner surface of a purification device according to claim 1, characterized in that: In step S3, the inner wall of the inner cylinder after degreasing is tested for the residual amount of esterification, and whether the test is qualified is determined according to the difference between the free acidity of the esterification of the inner wall before treatment and the free acidity of the esterification of the inner wall after treatment, the difference between the moisture content of the esterification of the inner wall before treatment and the moisture content of the esterification of the inner wall after treatment, and the proportion of residual alcohol. In the formula, C represents the qualified coefficient of the initial esterification residue detection of the inner wall of the inner cylinder, a represents the difference between the free acidity of the esterification of the inner wall before treatment and the free acidity of the esterification of the inner wall after treatment, m represents the difference between the moisture content of the esterification of the inner wall before treatment and the moisture content of the esterification of the inner wall after treatment, and s1 represents the proportion of residual alcohol in 1 gram of sample; When C < 83%, it means that the inner wall of the inner cylinder fails the initial esterification residue test; When C≥83%, it means that the inner wall of the inner cylinder has passed the initial esterification residue detection.

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

6. The method for degreasing the inner surface of a purification device according to claim 1, characterized in that: In step S6, the inner wall scratches of the inner cylinder and the corners are checked to see if residues are accumulated, so as to determine whether it is necessary to perform esterification residue detection on the residues; When there is obvious accumulation of residues, it is necessary to perform an esterification residue detection on the residues. If the esterification residue detection fails, it is necessary to re-enter step S5; When there is no accumulation of residues on the inner wall scratches and corners, or the esterification residue is tested to be qualified, it means that the inner surface of the inner cylinder is degreased.

7. The method for degreasing the inner surface of a purification device according to claim 1, characterized in that: In step S6, the residue is tested for the residual amount of esterification, and the difference between the saponification value of the inner wall esterification before treatment and the saponification value of the inner wall esterification after treatment, the proportion of esters contained in 1 gram of sample, and the proportion of fatty acids in 1 gram of sample are used to determine whether the residue is qualified for the residual amount of esterification. Then: In the formula, H represents the qualified coefficient of the secondary esterification residue detection of the inner wall of the inner cylinder, k represents the difference between the saponification value of the esterification of the inner wall before treatment and the saponification value of the esterification of the inner wall 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; When H≥80%, it means that the inner wall of the inner cylinder has passed the secondary esterification residue test; When H is less than 80%, it means that the secondary esterification residue detection on the inner wall of the inner cylinder is unqualified.

Images