A defoaming method for concentrator based on normal distribution de-extreme finite step length

Abstract

The present application belongs to the field of food, beverage, traditional Chinese medicine, plant extraction and health product production and manufacturing, and particularly relates to a concentrator defoaming method based on normal distribution and extreme value removal finite step length. The present application is based on the fact that the liquid level of the concentrator conforms to the normal distribution law in work, combines the characteristics of the concentrator liquid level control, removes the extreme value of the sampled concentrator liquid level data, performs first-in-first-out operation, and calculates the opening degree of the current defoaming regulating valve based on the normal distribution characteristics of the liquid level. The method realizes intelligent control of the concentrator defoaming, solves the control problem of continuous defoaming and frequent emptying of the concentrator in the production process, and improves the working efficiency of the concentrator and the product yield.

Description

Technical Field

[0001] This invention belongs to the field of food, beverage, traditional Chinese medicine, plant extracts and health products manufacturing, and specifically relates to a defoaming method for concentrators based on a normal distribution to remove extreme values ​​with a finite step size. Background Technology

[0002] Currently, in the production of plant extracts, raw materials for pharmaceuticals, traditional Chinese medicine, and health products, vacuum concentrators are mainly used as the primary equipment for product purification and solvent recovery. Taking a single-effect vacuum concentrator as an example, under normal operation, the vacuum concentrator operates under negative pressure, and the liquid is circulated and concentrated in the evaporation chamber under negative pressure. The concentrator relies on a level gauge to measure the liquid level in the evaporation chamber. However, when the concentrator has not established a steady working state, or during the concentration process of certain special products, a large amount of foam is generated. If this foam is not defoamed in time, the concentrated product will escape with the vacuum system, resulting in product loss, reduced product yield, and affecting the working efficiency of the concentrator. Currently, the common method to deal with this situation is to use a valve to break the vacuum and defoam. However, this method has the following drawbacks in actual production: 1. The method can only use simple data processing and timed opening of the valve; 2. For products with high saponin content, a large amount of foaming occurs, and the valve will be opened continuously, preventing the concentrator from establishing a vacuum and circulating the concentrated liquid; 3. The concentrator's defoaming action is frequent, and the level of intelligence in the defoaming method is low. Currently, the above-mentioned problems have not been solved in actual production. Summary of the Invention

[0003] The purpose of this invention is to provide a defoaming method for concentrators based on a normal distribution with finite step size for removing extreme values. This method enables intelligent control of the liquid level defoaming in the evaporation chamber of the concentrator, and employs a regulating valve for continuous and adjustable defoaming control of the concentrator, thereby reducing the loss of concentrated liquid and improving the evaporation efficiency and product yield of the concentrator.

[0004] A condenser defoaming method based on normal distribution to remove extrema with finite step size includes the following steps:

[0005] S1 uses a single-effect vacuum condenser as the control model. The liquid level in the evaporation chamber is measured by a capacitor level gauge installed in the evaporation chamber, and the cavitation is broken and defoamed by a cavitation regulating valve.

[0006] S2, the sampling interval for the liquid level is 1 second, and a first-in-first-out array of 60 data points is created to store the liquid level data of the past 60 seconds;

[0007] S3, the calculation cycle is 10 seconds, and the opening degree of the venting control valve is calculated every 10 seconds;

[0008] S4. Each time a calculation is performed, the liquid level values ​​in the sampling array are first counted. If the number of liquid level values ​​exceeding the forced venting value exceeds 4, the venting control valve will directly operate to the maximum value. If the number of liquid level values ​​exceeding the forced venting value does not exceed 4, the average value in the array is calculated as the estimated value of the current liquid level.

[0009] S5, the liquid level change of the entire concentrator conforms to the characteristics of a normal distribution, the estimated value of the current liquid level of the concentrator is standardized, and the probability cumulative area of ​​the current liquid level value is calculated.

[0010] S6. Calculate the opening degree of the venting control valve based on the opening degree range of the venting control valve and the cumulative area of ​​the probability of the standard normal distribution.

[0011] S7. Compare the absolute value of the difference between the opening degree of the venting control valve and the current opening degree of the control valve with the dead zone step length of the control valve. If it is less than the dead zone step length, the control valve will not operate this time. If it is greater than the dead zone step length, the control valve will operate to the calculated opening degree.

[0012] Furthermore, the data storage in S2 uses a first-in-first-out array, and is calculated every 10 seconds.

[0013] Furthermore, the capacitive level gauge can also measure the height of the concentrated liquid foam after it has foamed.

[0014] The beneficial effects of this invention are as follows:

[0015] This invention is based on the normal distribution of liquid level in a concentrator during operation. Combining this with the characteristics of concentrator level control, it performs operations such as removing extreme values ​​and applying a first-in-first-out (FIFO) principle on the sampled concentrator level data. Based on the normal distribution characteristics of the liquid level, it calculates the current opening degree of the defoaming regulating valve. This method achieves intelligent control of concentrator defoaming, solving the control problems of continuous defoaming and frequent void breaking during the production process, thus improving the working efficiency of the concentrator and the product yield. Attached Figure Description

[0016] Figure 1 This is a typical diagram of a single-effect vacuum concentrator system with defoaming function;

[0017] Figure 2 This is a flowchart of the present invention;

[0018] Figure 3 This is a standard normal distribution table;

[0019] Figure 4 This is a real-time liquid level curve for a single-effect concentrator in a pharmaceutical factory. Detailed Implementation

[0020] The present invention will now be further described with reference to the accompanying drawings.

[0021] Combination Figure 1 The main components of the system are as follows:

[0022] A is the evaporation chamber of a single-effect vacuum concentrator; B is the venting regulating valve; and C is the capacitive level gauge.

[0023] like Figure 1 As shown, after the single-effect vacuum evaporator starts working, the concentrate circulates and evaporates in the evaporation chamber. A capacitive level gauge is installed in the evaporation chamber to measure the concentrate level and the height of the foam after foaming. The system is equipped with a venting regulating valve, whose opening can be continuously adjusted to allow venting air to enter for defoaming.

[0024] After the single-effect vacuum concentrator has been operating continuously, a concentrator defoaming method based on normal distribution to remove extrema with a finite step size begins to work. The specific process is as follows: Figure 2 As shown.

[0025] First, data sampling is performed. The sampling interval for the liquid level Lt in the evaporation chamber of the single-effect vacuum evaporator is 1 second. A first-in-first-out array of 60 data points is established to store the liquid level data for the past 60 seconds. The table below shows the liquid level values ​​in the evaporation chamber collected by a pharmaceutical factory for one minute during production, in mm:

[0026]

[0027]

[0028] During the operation of the entire single-effect vacuum concentrator, the liquid level sampling value Lt follows a normal probability distribution with position parameter μ and scale parameter σ, i.e., Lt~N(μ, σ). 2 ).

[0029] Based on the actual working conditions of this single-effect vacuum concentrator, we know that μ = 595 mm, σ = 135 mm, and the warning liquid level Lt is... max =1300mm.

[0030] The method calculates every 10 seconds. In the current calculation, there is no liquid level in the array that is higher than the warning level Lt. max Therefore, the number of times the warning level is reached is C = 0, and the average value of the current level is calculated simultaneously. If C ≥ 4, then directly open the vent control valve to its maximum opening Po. max Here, Po is taken according to the actual production situation on site. max =75%, while the minimum opening of the venting regulating valve Po min =15%.

[0031] At this time standardization,

[0032] At this point, the standardized cumulative distribution function can be calculated. Substituting η = 0.4631 into the formula, according to... Figure 3 We can find the standard normal distribution table.

[0033] At this point, calculate the current opening degree Po of the venting control valve. cal ,as follows:

[0034] Po cal =(Po max -Po min )*0.6772+Po min = (75% - 15%) * 0.6772 + 15% = 55.63%.

[0035] If we assume the venting control valve is activated for the first time, then the current venting control valve opening Po is... now =Po cal =55.63%, the algorithm calculation is now complete.

[0036] Ten seconds later, the second calculation begins. First, the array of data from the previous 10 seconds is updated. Following a first-in-first-out (FIFO) rule, the latest 10 seconds of liquid level sampling data is updated. The updated array is as follows, in mm:

[0037] Serial Number 1 2 3 4 5 6 7 8 9 10 liquid level value 521.22 582.74 617.32 604.69 662.89 717.12 704.30 692.22 674.14 669.81 Serial Number 11 12 13 14 15 16 17 18 19 20 liquid level value 659.47 649.33 640.57 625.90 613.91 610.87 711.13 704.85 685.30 673.59 Serial Number 21 22 23 24 25 26 27 28 29 30 liquid level value 663.72 652.28 641.40 623.04 614.74 608.65 692.13 709.47 689.64 680.97 Serial Number 31 32 33 34 35 36 37 38 39 40 liquid level value 722.29 693.88 669.90 730.96 707.90 715.46 680.97 709.28 698.21 686.22 Serial Number 41 42 43 44 45 46 47 48 49 50 liquid level value 613.82 586.98 684.29 708.27 698.21 915.89 909.98 826.79 785.10 651.73 Serial Number 51 52 53 54 55 56 57 58 59 60 liquid level value 635.31 619.81 605.24 622.49 714.54 698.21 688.81 670.73 665.47 652.65

[0038] Under the current calculation, no liquid level in the array is higher than the warning level Lt. max Therefore, the number of times the warning level is reached is C = 0, and the average value of the current level is calculated simultaneously.

[0039] At this time

[0040] At this point, the standardized cumulative distribution function can be calculated. Substituting η = 0.6008 into the formula, according to... Figure 3 We can find the standard normal distribution table.

[0041] At this point, calculate the current opening degree Po of the venting control valve. cal ,as follows:

[0042] Po cal =(Po max -Po min )*0.7257+Po min = (75% - 15%) * 0.7257 + 15% = 58.54%.

[0043] At this point, calculate Po. now -Pocal =55.63% - 58.54% = -2.91%, taking the absolute value as 2.91%, that is, the step length of this movement is 2.91%.

[0044] Based on the regulating characteristics of the venting control valve, the dead zone step Po is determined. dead =2.5%, indicating that the step size calculated by this method is greater than the dead zone step size, so the venting control valve will activate in this operation. At this time, Po now =Po cal =58.54%.

[0045] And so on, after 10 seconds the data in the first-in-first-out stack is updated, and the method enters the next calculation process.

[0046] A screenshot of the liquid level curve at a single-effect concentrator in a pharmaceutical factory is shown below. Figure 4 As shown in the figure, this method has a good control effect, fast response speed, and stable liquid level control.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A condenser defoaming method based on normal distribution to remove extrema with finite step size, characterized in that, Includes the following steps: S1 uses a single-effect vacuum condenser as the control model. The liquid level in the evaporation chamber is measured by a capacitor level gauge installed in the evaporation chamber, and the cavitation is broken and defoamed by a cavitation regulating valve. S2, the sampling interval for the liquid level is 1 second, and a first-in-first-out array of 60 data points is created to store the liquid level data of the past 60 seconds; S3, the calculation cycle is 10 seconds, and the opening degree of the venting control valve is calculated every 10 seconds; S4. Each time a calculation is performed, the liquid level values ​​in the sampling array are first counted. If the number of liquid level values ​​exceeding the forced venting value exceeds 4, the venting control valve will directly operate to the maximum value. If the number of liquid level values ​​exceeding the forced venting value does not exceed 4, the average value in the array is calculated as the estimated value of the current liquid level. S5, the liquid level change of the entire concentrator conforms to the characteristics of a normal distribution, the estimated value of the current liquid level of the concentrator is standardized, and the probability cumulative area of ​​the current liquid level value is calculated. S6. Calculate the opening degree of the venting control valve based on the opening degree range of the venting control valve and the cumulative area of ​​the probability of the standard normal distribution. S7. Compare the absolute value of the difference between the opening degree of the venting control valve and the current opening degree of the control valve with the dead zone step length of the control valve. If it is less than the dead zone step length, the control valve will not operate this time. If it is greater than the dead zone step length, the control valve will operate to the calculated opening degree.

2. The defoaming method for concentrators based on normal distribution with finite step size for removing extrema, as described in claim 1, is characterized in that... The data storage in S2 uses a first-in-first-out array, and is calculated every 10 seconds.

3. The defoaming method for concentrators based on normal distribution with finite step size for removing extrema, as described in claim 1, is characterized in that... The capacitive level gauge can also measure the height of the concentrated liquid foam after it has foamed.

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