阅读说明：本技术 配料添加系统以及配料添加方法 (Ingredient adding system and ingredient adding method ) 是由 钟蔚 肖荣和 李鹏超 于 2019-11-15 设计创作，主要内容包括：本发明公开了一种配料添加系统以及配料添加方法,涉及烟草机械领域。该配料添加系统包括第一动力源、输送管路以及计量组件。第一动力源被构造为变频的；输送管路与第一动力源连接,第一动力源被构造为将配料经由输送管路的第一端口输送至输送管路的第二端口。计量组件安装于输送管路,且被构造为测量经由输送管路输送的配料的重量。上述技术方案,不仅能够实现配料自动、精准添加,还能自适应配料自身的特性,以及自疏通输送管路的效果。(The invention discloses a batching adding system and a batching adding method, and relates to the field of tobacco machinery. The ingredient adding system comprises a first power source, a conveying pipeline and a metering assembly. The first power source is configured to be variable frequency; the conveying line is connected with a first power source configured to convey the ingredient to a second port of the conveying line via a first port of the conveying line. The metering assembly is mounted to the delivery line and is configured to measure a weight of the ingredient delivered via the delivery line. Above-mentioned technical scheme not only can realize batching automation, accurate interpolation, can also self-adaptation batching self characteristic to and self-dredging pipeline's effect.)

1. An ingredient adding system, comprising:

a first power source (1) configured to be variable frequency;

a conveying line (2) connected with the first power source (1), the first power source (1) being configured to convey an ingredient via a first port (21) of the conveying line (2) to a second port (22) of the conveying line (2); and

a metering assembly (3) mounted to the conveying line (2) and configured to measure the weight of the ingredient conveyed via the conveying line (2).

2. The ingredient addition system according to claim 1, further comprising:

a first control valve (4) mounted to the delivery line (2) and configured to control a dose delivery rate within the delivery line (2).

3. The ingredient adding system according to claim 2, characterized in that the first control valve (4) comprises a proportional valve.

4. The ingredient adding system according to claim 1, wherein the first power source (1) comprises:

a pump (11); and

a frequency converter (12) electrically connected to the pump (11) and used for controlling the operating frequency of the pump (11).

5. The ingredient addition system according to claim 1, further comprising:

a cleaning assembly (5) in communication with the delivery line (2) and configured to clean the delivery line (2).

6. The ingredient adding system according to claim 5, wherein the washing assembly (5) comprises:

a cleaning pipe (51) communicating with the delivery line (2); and

a heating assembly (52) mounted to the cleaning tube (51) or located adjacent to the cleaning tube (51) and configured to heat cleaning fluid within the cleaning tube (51).

7. The ingredient adding system according to claim 6, wherein the washing assembly (5) further comprises:

and the drying pipeline (53) is communicated with the conveying pipeline (2) and is used for conveying air drying fluid to the conveying pipeline (2).

8. The ingredient addition system according to claim 6, further comprising:

a second control valve (6) mounted between a second port (22) of the delivery line (2) and the purge assembly (5);

wherein the second control valve (6) is in a first working position, and the delivery pipeline (2) is used for delivering ingredients to the blending tank (9); the second control valve (6) is located at a second working position, and the cleaning assembly (5) is used for conveying cleaning liquid to the conveying pipeline (2).

9. The ingredient addition system according to claim 8, wherein the second control valve (6) comprises a three-way valve.

10. The ingredient addition system according to claim 1, further comprising:

and the controller (7) is in driving connection with the first power source (1) and is used for controlling the working frequency of the first power source (1).

11. The ingredient addition system according to claim 10, further comprising:

the input and output assembly (8) is electrically connected with the controller (7), and the controller (7) is used for controlling the working frequency of the first power source (1) according to the information transmitted by the input and output assembly (8).

12. An ingredient adding method is realized by the ingredient adding system of any one of claims 1 to 11, and is characterized by comprising the following steps:

determining the mass required to be added according to the types of the ingredients;

determining the working frequency of the first power source (1) according to the type of the ingredient;

-placing the first port (21) of the delivery line (2) into a dosage tank (14) in which the dosage is located;

-activating the first power source (1) to add the ingredient to the blending tank (9) until the desired added mass is reached.

13. The ingredient adding method according to claim 12, further comprising the steps of:

after the mass of the ingredients added to the blending tank (9) reaches the set proportion of the mass required to be added, the adding speed of the ingredients is reduced until the mass required to be added is reached.

14. The ingredient adding method according to claim 12, further comprising the steps of:

after the addition of the former ingredient is finished, cleaning the conveying pipeline (2);

the next ingredient is continued to be added.

15. The ingredient adding method according to claim 14, further comprising, after said cleaning of said delivery line (2), the steps of:

drying the conveying line (2).

16. The ingredient adding method according to claim 12, further comprising the steps of:

judging whether the conveying pipeline (2) is blocked or not;

and if the blockage occurs, changing the working frequency of the first power source (1) until the conveying pipeline (2) is communicated.

17. The ingredient adding method according to claim 16, wherein said changing the operating frequency of said first power source (1) comprises the steps of:

the operating frequency of the first power source (1) is increased or decreased irregularly.

Technical Field

The invention relates to the field of tobacco machinery, in particular to a batching and adding system and a batching and adding method.

Background

Prior to perfume dispensing, each ingredient is stored in a set location. When the raw materials are stored, the raw materials needing manual metering are placed on a shelf in a manual batching area with the height of 1.5 meters after being scanned. Before the material is placed into the dispensing canister, the system verifies that the two bar codes match by scanning the bar code on the package and the bar code at which the dispensing canister is entered to begin feeding. If the materials are not matched, the system sends out an alarm signal, and the feeding to the dosing tank is stopped manually. When the two bar codes are matched, the feeding is prompted to have no error information, and the manual material pouring operation can be carried out at the moment. The concrete pouring operation is as follows:

when feeding is started, the required raw material weight and the adding progress prompt bar of the batch are displayed on the system operation screen, the adding progress prompt bar is gradually filled by the green progress bar according to the percentage of the actual weight in the required weight, green flicker is generated in the prompt bar when the actual weight and the required weight are close to a target value (generally, the difference is 0.2 kg), and the flickering prompt bar turns red when the actual weight and the required weight are manually controlled within the precision requirement range, so that the prompt is not added manually. And (4) finishing the manual material pouring operation, scanning the bar code of the fed tank, automatically comparing the weight on the barrel with the actual weight of the fed tank by the system, and sending an alarm signal if the difference exceeds a set range. The whole batching process has the following defects:

(1) the goods shelves of the manual batching area have three layers, and during batching, an operator needs to take the barrel from the goods shelves according to the raw materials prompted by the system, and puts the raw material barrel back to the original position after batching, and additionally, the used plastic cup is cleaned, which wastes time and labor.

(2) In the batching process, an operator needs to hold a raw material barrel to add raw materials into a blending tank in the whole process and stares at a progress bar of a display screen tightly, required raw material weight is added through the cooperation of eyes and hand feeling, the requirement of precision is met, once the precision exceeds the standard, the adding amount of all raw materials in a formula needs to be increased in the same proportion to balance, and therefore certain risk exists in manual material pouring.

Disclosure of Invention

In one aspect, the present invention provides a system for adding ingredients, including:

a first power source configured to be variable frequency;

a delivery conduit connected to the first power source, the first power source configured to deliver the ingredient to the second port of the delivery conduit via the first port of the delivery conduit; and

a metering assembly mounted to the delivery line and configured to measure a weight of the ingredient delivered via the delivery line.

In some embodiments, the ingredient addition system further comprises:

a first control valve mounted to the delivery line and configured to control a ingredient delivery rate within the delivery line.

In some embodiments, the first control valve comprises a proportional valve.

In some embodiments, the first power source comprises:

a pump; and

and the frequency converter is electrically connected with the pump and is used for controlling the working frequency of the pump.

In some embodiments, the ingredient addition system further comprises:

a cleaning assembly in communication with the delivery line and configured to clean the delivery line.

In some embodiments, the washing assembly comprises:

the cleaning pipe is communicated with the conveying pipeline; and

a heating assembly mounted to or adjacent to the cleaning tube and configured to heat cleaning fluid within the cleaning tube.

In some embodiments, the washing assembly further comprises:

and the drying pipeline is communicated with the conveying pipeline and is used for conveying air drying fluid to the conveying pipeline.

In some embodiments, the ingredient addition system further comprises:

the second control valve is arranged between the second port of the conveying pipeline and the cleaning assembly;

the second control valve is located at a first working position, and the conveying pipeline is used for conveying ingredients to the blending tank; the second control valve is located at a second working position, and the cleaning assembly is used for conveying cleaning liquid to the conveying pipeline.

In some embodiments, the second control valve comprises a three-way valve.

In some embodiments, the ingredient addition system further comprises:

and the controller is in driving connection with the first power source and is used for controlling the working frequency of the first power source.

In some embodiments, the ingredient addition system further comprises:

and the input and output assembly is electrically connected with the controller, and the controller is used for controlling the working frequency of the first power source according to the information transmitted by the input and output assembly.

The invention also provides a method for adding ingredients, which is realized by adopting the ingredient adding system provided by any technical scheme of the invention, and the method for adding ingredients comprises the following steps:

determining the mass required to be added according to the types of the ingredients;

determining the working frequency of the first power source according to the type of the ingredients;

putting the first port of the conveying pipeline into a batching tank where the batching is positioned;

the first power source is activated to add the ingredient to the blending tank until a desired added mass is achieved.

In some embodiments, the ingredient addition method further comprises the steps of:

and after the mass of the ingredients added into the blending tank reaches the set proportion of the mass required to be added, reducing the adding speed of the ingredients until the mass required to be added is reached.

In some embodiments, the ingredient addition method further comprises the steps of:

after the addition of the former ingredient is finished, cleaning the conveying pipeline;

the next ingredient is continued to be added.

In some embodiments, after said cleaning said transfer line, further comprising the steps of:

drying the conveying pipeline.

In some embodiments, the ingredient addition method further comprises the steps of:

judging whether the conveying pipeline is blocked or not;

and if the blockage occurs, changing the working frequency of the first power source until the conveying pipeline is conducted.

In some embodiments, the changing the operating frequency of the first power source specifically includes the steps of:

the operating frequency of the first power source is increased or decreased irregularly.

Above-mentioned technical scheme, first power supply adopts the frequency conversion, can both automatic feed to almost any batching. For the ingredients with higher viscosity, the working frequency of the first power source is high; for ingredients with a relatively low viscosity, the operating frequency of the first power source is low. And, for the same ingredient, if the weight weighed by the metering component in a set time, for example, 5 seconds, is not changed, the blockage of the conveying pipeline is judged. Because the first power source is variable frequency, after the conveying pipeline is blocked, the working frequency of the first power source is randomly changed until the conveying pipeline is conducted. Therefore, according to the technical scheme, automatic and accurate addition of ingredients can be realized, the characteristics of the ingredients can be self-adaptive, and the effect of self-dredging a conveying pipeline is achieved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

FIG. 1 is a schematic charging diagram of an ingredient addition system provided by an embodiment of the present invention;

FIG. 2 is a schematic illustration of a cleaning of the ingredient addition system provided by an embodiment of the present invention;

FIG. 3 is a schematic air-drying diagram of an ingredient adding system according to an embodiment of the present invention;

fig. 4 is a schematic flow chart of an ingredient adding method according to an embodiment of the present invention.

Detailed Description

The technical solution provided by the present invention is explained in more detail with reference to fig. 1 to 4.

The embodiment of the invention provides a batching adding system, which comprises a first power source 1, a conveying pipeline 2 and a metering assembly 3.

The first power source 1 is constructed to be variable frequency. First power supply 1 can realize reasonable stable extraction velocity of flow to the raw materials of different viscosities, reaches the effect that reduces the cost of labor.

In the embodiment of the invention, the adopted ingredients are fluid ingredients. Different ingredients have different properties and different viscosity degrees. The first power source 1 is variable-frequency, and for the ingredients with higher viscosity, the working frequency of the first power source 1 is high; for ingredients with a relatively low viscosity, the operating frequency of the first power source 1 is low. And, for the same ingredient, if the weighing weight of the metering component 3 is not changed within a set time, for example, within 5 seconds, it is determined that the conveying pipeline 2 is blocked. Because the first power source 1 is variable frequency, after the conveying pipeline 2 is blocked, the working frequency of the first power source 1 is randomly changed until the conveying pipeline 2 is conducted.

It can be seen that the first power source 1 adopts frequency conversion, not only can self-adapt to the characteristics of the ingredients, but also has the function of self-dredging the conveying pipeline 2.

In some embodiments, the first power source 1 comprises a pump 11 and a frequency converter 12. The frequency converter 12 is electrically connected to the pump 11, and the dashed lines in fig. 1 to 3 indicate that there is an electrical connection between the components. And is used to control the operating frequency of the pump 11. The pump 11 is, for example, a variable displacement pump 11 or a fixed displacement pump 11. But its operating frequency can be adjusted. The frequency converter 12 is used to control the operating frequency of the pump 11 so that the pump 11 changes the operating frequency if required.

The rotating speed of the motor 13 of the pump 11 is set by the frequency converter 12 of the pump 11, so that the rotating speed of the raw materials with different viscosities can be set, and the effect of setting the extraction flow rate according to requirements is realized. The whole extraction process of each ingredient is divided into two stages, the running speed of the frequency converter 12 in the first stage is kept unchanged, and the flow of the raw materials is ensured to be stable; the frequency of the frequency converter 12 in the second stage is reduced, the flow rate of the raw material is controlled to be a small value, so that accurate addition is realized, and the phenomenon of excessive addition caused by overlarge flow rate is reduced.

Referring to fig. 1, the conveying line 2 is connected to a first power source 1, the first power source 1 being configured to convey the ingredients via a first port 21 of the conveying line 2 to a second port 22 of the conveying line 2. The first power source 1 is used to provide pumping power or other power to the ingredients to be transported by the conveying line 2.

The transfer line 2 is, for example, a rubber tube. The diameter of the transfer line 2 is related to the mass of ingredient that needs to be added. If the mass of the ingredients to be added is large, the conveying pipeline 2 can adopt a thicker pipe diameter; otherwise, a smaller pipe diameter is adopted.

Referring to fig. 1, a metering assembly 3 is mounted to the delivery line 2 and is configured to measure the weight of the ingredient delivered via the delivery line 2. The metering assembly 3 is, for example, a mass flow meter or other flow, mass sensor. By means of the metering assembly 3, an accurate calculation of the amount of ingredient added to the blending tank 9 is achieved.

The metering component 3 can meet the adding requirements of different weights, and the process weight and the accumulated weight can be compared with each other, so that the effects of improving the batching precision and reducing the risk are achieved.

Referring to fig. 1, the ingredient addition system further comprises a first control valve 4, the first control valve 4 being mounted to the conveying line 2 and configured to control an ingredient conveying speed within the conveying line 2.

Both the first control valve 4 and the metering assembly 3 may be electrically connected to a later controller 7 to precisely control the amount of ingredient added.

For example, the total addition amount of the ingredients is a, and the first control valve 4 is in a completely opened state within the mass range of 0-90% a; when the addition amount reaches more than 90% a, the opening degree of the first control valve 4 is adjusted so that the addition speed of the ingredients becomes slow to prevent the addition at a large flow rate from causing an excessive amount of the ingredients. The opening degree of the first control valve 4 may correspond to the first stage and the second stage of the frequency converter 12 described above, in which the opening degree of the first control valve 4 is large; in the second stage, the opening degree of the first control valve 4 is small.

In some embodiments, the first control valve 4 comprises a proportional valve.

The ingredient adding system is used for adding various ingredients. In order to realize light weight of the equipment, only one set of conveying pipeline 2 and the first power source 1 can be arranged, and all ingredients are conveyed into the blending tank 9 through the set of conveying pipeline 2 and the first power source 1.

To prevent cross-contamination between ingredients, referring to fig. 1, in some embodiments, the ingredient addition system further includes a purge assembly 5, the purge assembly 5 being in communication with the transfer line 2 and configured to purge the transfer line 2.

The cleaning assembly 5 includes, for example, a water pump and a cleaning liquid pipeline, or directly communicates the cleaning liquid pipeline with a cleaning liquid with pressure, so as to clean the conveying pipeline 2. The cleaning component 5 can realize the recovery of raw materials in the pipeline and the cleaning of residual feed liquid so as to avoid mixing the brands.

In some embodiments, the cleaning assembly 5 includes a cleaning tube 51 and a heating assembly 52. The cleaning pipe 51 communicates with the delivery line 2. The heating assembly 52 is mounted to the cleaning tube 51 or located adjacent to the cleaning tube 51 and is configured to heat the cleaning liquid within the cleaning tube 51. The hot cleaning liquid makes it easier to clean the conveying line 2. The wastewater after washing is discharged into the washing tank 10.

The heating unit 52 is specifically a heater, a heating rod, or the like.

In some embodiments, the washing assembly 5 further comprises a drying line 53, the drying line 53 being in communication with the conveying line 2 and being adapted to convey an airing fluid to the conveying line 2.

The drying line 53 is used to introduce a drying fluid, such as hot air, into the conveying line 2 to dry the entire inner pipe wall of the conveying line 2.

In some embodiments, the drying line 53 is provided with a pressure regulating valve 54 to control the pressure of the drying gas within the drying line 53.

In some embodiments, the drying line 53 is provided with a pneumatic valve 55 to control whether the drying line 53 is conductive.

The drying circuit 53 may be provided with two branches, one of which is provided with both the pressure regulating valve 54 and the pneumatic valve 55, and the other of which is provided with only the pneumatic valve 55. This allows for more convenient control of the pressure of the drying fluid.

Referring to fig. 1, in some embodiments, the ingredient addition system further comprises a second control valve 6, the second control valve 6 being mounted between the second port 22 of the delivery conduit 2 and the wash assembly 5. Wherein the second control valve 6 is in the first working position, and the delivery line 2 is used for delivering ingredients to the blending tank 9; the second control valve 6 is in the second working position and the cleaning assembly 5 is used to deliver cleaning liquid to the delivery line 2. The second control valve 6 is arranged, so that the structure of the ingredient adding system is simplified as much as possible.

In some embodiments, the second control valve 6 comprises a three-way valve.

The three-way valve has three working ports A, B, C. The working port a communicates with the second port 22 of the delivery line 2.

When the three-way valve is in the first operating position, the working port A, B is open. The blending tank 9 is positioned below the working port B. The ingredients fall under gravity from the working opening B into the blending tank 9. The ingredient addition is realized in this state.

When the three-way valve is in the second operating position, the working port A, C is open. The cleaning liquid as well as the drying fluid in the cleaning assembly 5 are both delivered to the working port a via the working port C and then to the first port 21 of the delivery line 2. In this state, the cleaning and drying of the transfer line 2 are achieved.

In some embodiments, the ingredient addition system further comprises a controller 7, the controller 7 being in driving connection with the first power source 1 and being configured to control the operating frequency of the first power source 1.

The controller 7 may also be connected to the cleaning assembly 5 to control parameters such as whether the cleaning assembly 5 is operating, the flow rate of the cleaning fluid, the pressure of the drying fluid, etc.

In some embodiments, the ingredient adding system further comprises an input and output assembly 8, the input and output assembly 8 is electrically connected with the controller 7, and the controller 7 is used for controlling the working frequency of the first power source 1 according to the information transmitted by the input and output assembly 8.

It is understood that the input-output assembly 8 may also be one of the modules of the controller 7.

The input/output assembly 8 is used for signal transmission between each electronic device and the controller 7. For example, the controller 7 determines the operating frequency of the first power source 1 and then transmits the signal to the first power source 1 via the input-output assembly 8. The metering assembly 3 acquires the addition amount of the ingredient in real time and transmits the addition amount of the ingredient to the controller 7. When the amount of added ingredient reaches the required ratio, the controller 7 sends a control signal, which is transmitted to the first control valve 4 via the input-output assembly 8 to adjust the opening of the first control valve 4.

Referring to fig. 4, other embodiments of the present invention provide a method for adding ingredients, which is implemented by using an ingredient adding system provided in any technical solution of the present invention. The ingredient adding method comprises the following steps:

and S100, determining the required added mass according to the types of the ingredients.

Such as a formulated sugar flavor, which includes five ingredients. After the total mass of sugar flavor to be formulated is determined, the mass of each ingredient is also determined.

And S200, determining the working frequency of the first power source 1 according to the type of the ingredients.

The nature of each ingredient is different and the required pumping frequency of the pump 11 is different. In actual production, the working frequency of the first power source 1 corresponding to each ingredient is determined and is prestored in the controller 7.

The foregoing steps S100 and S200 do not limit the sequence of execution. Step S100 may be performed first, and then step S200 may be performed as shown in fig. 4. Step S200 may be executed first, and then step S100 may be executed.

Step S300, the first port 21 of the conveying pipeline 2 is placed into the batching tank 14 where the batching is located.

Which ingredient needs to be added, the first port 21 of the transfer line 2 is placed into the head tank for which ingredient.

Step S400, the first power source 1 is activated to add ingredients to the blending tank 9 until the desired added mass is reached.

In some embodiments, the ingredient addition method further comprises the steps of:

and step S500, after the mass of the ingredients added into the blending tank 9 reaches the set proportion of the mass required to be added, reducing the adding speed of the ingredients until the mass required to be added is reached.

In some embodiments, the ingredient addition method further comprises the steps of:

and step S600, after the addition of the previous ingredient is finished, cleaning the conveying pipeline 2.

In some embodiments, after step S600, the following steps are further included:

and step S700, drying the conveying pipeline 2.

After the conveying pipeline 2 is cleaned and dried, the next ingredient is continuously added.

In the ingredient adding process, whether the conveying pipeline 2 is blocked or not is judged in real time. The method comprises the following specific steps:

firstly, judging whether the conveying pipeline 2 is blocked or not;

secondly, if a blockage occurs, the operating frequency of the first power source 1 is changed until the conveying line 2 is conducted.

Specifically, changing the operating frequency of the first power source 1 specifically includes the steps of: the operating frequency of the first power source 1 is increased or decreased irregularly.

The irregular increase or decrease of the operating frequency of the first power source 1 causes a pulse force to be formed in the transfer piping 2, which facilitates the conduction of the transfer piping 2.

Some specific embodiments are described below.

Firstly, material taking process and cleaning process

The first power source 1 and the cleaning assembly 5 of the embodiment of the invention are used for realizing automatic material taking and automatic cleaning. The method comprises the following specific steps:

1. the frequency of the frequency converter 12 is preset, and ingredients are extracted through the preset frequency due to the characteristics of different viscosities, different flowability, small weight and the like of the raw materials. When the pump 11 is not pumping, the frequency of the frequency converter 12 is suitably increased until the metering assembly 3 reaches a stable and reasonable value. When the flow rate is too large, the frequency of the frequency converter 12 is appropriately lowered. The experiment was repeated in this way to obtain a fixed extraction frequency value for each material. Example (c): viscosity number 8220 (dimensionless) for the H/B22044 feedstock; viscosity 23215 (dimensionless) of JM8690 starting material. The frequency of the H/B22044 raw material preset frequency converter 12 is 20Hz, and the frequency of the JM8690 raw material preset frequency converter 12 is 45Hz due to the large viscosity.

Before actual batching, but sweep the sign indicating that the raw materials type that adds at present, the system sets up the frequency of converter 12 automatically, and the extraction process divides into two stages, and first stage converter 12 functioning speed keeps unchangeable, guarantees that raw materials flow is stable, and back end converter 12 frequency reduces, and control raw materials flow is at less numerical value. Example (c): the frequency of the H/B22044 raw material first-stage frequency converter 12 is 20Hz, and the frequency of the rear-stage frequency converter 12 is reduced to 8 Hz; the frequency of the first-stage frequency converter 12 of the JM8690 raw material is 45Hz, and the frequency of the rear-stage frequency converter 12 is reduced to 15 Hz;

2. in the cleaning process, only the feed liquid is recovered, the first port 21 of the conveying pipeline 2 is placed in the cleaning pool, the cleaning button is clicked on the site, and the second control valve 6 is adjusted to the second working position. The system firstly introduces purified water heated by the heating component 52 into the pipeline according to a preset program, and cleans the pipeline, wherein the cleaning time is set to 3 minutes for example; after cleaning, the pneumatic valve 55 is opened to blow water in the pipe, and the blowing time is set to 1 minute, for example.

Secondly, the automatic feeding process is as follows

The metering assembly 3 provided by the embodiment of the invention is used for replacing a manual material pouring process so as to improve accurate addition of ingredients. The method comprises the following specific steps:

the metering component 3 sets the cumulative amount of the H/B22044 raw material according to the weight required by the formula, when the cumulative amount is close to 90 kg of the weight of the formula, the opening degree of the first control valve 4 behind the mass flow meter is gradually reduced from 100% to 10%, when the cumulative amount of the mass flow meter reaches a set value of 90 kg, the frequency of the frequency converter 12 is reduced to 8Hz, the first control valve 4 is reduced to a smaller opening degree of 5%, the rest raw material is added in a dropping mode until the cumulative weight of the blending tank 9 reaches the set value, the second control valve 6 is closed, and the motor 13 of the pump 11 stops running; if the cumulative weight of the preparation tank 9 has previously reached the set value, the second control valve 6 at the inlet of the preparation tank 9 is immediately closed and the motor 13 of the pump 11 stops.

According to the technical scheme, the labor cost for taking materials, placing materials and cleaning is saved; meanwhile, the condition that all raw materials need to be manually thrown up in the same proportion (namely increased) due to the fact that the raw material adding precision exceeds the standard caused by possible errors in the manual material pouring process is avoided.

In the description of the present invention, it is to be understood that the terms "central", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be considered as limiting the scope of the present invention.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: it is to be understood that modifications may be made to the technical solutions described in the foregoing embodiments, or equivalents may be substituted for some of the technical features thereof, but such modifications or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.