Data acquisition, manual control technology in the production of modern applications such as extraction

1 question raised

At present, the extraction and production of botanical drugs in China faces five major problems, which have already restricted the development of the botanical drug industry. These five major problems are: (1) resource shortage, rising raw material prices, low yield of finished products; (2) lack of human resources The quality of the operating staff is uneven and the work efficiency is low; (3) the energy waste is high and the production cost is high; (4) the production process lacks system management, and the production operation and equipment management consumes a large amount; (5) the investment is large and the waste is serious, resulting in Management costs are too high, product prices remain high, and market competitiveness is low

In response to the above problems, we have carried out in-depth and extensive research on the relationship between pharmaceutical technology, equipment structure, production operation, production management and other possible problems in combination with the rich field experience accumulated in turnkey projects for many years. In particular, in-depth research and development of the problems encountered in the modernization of plant medicine production in the process, equipment and control. At the same time, the plant drug extraction production R&D center was established in the factory. Through repeated practice, the relevant data was effectively explored, and the process, equipment structure and control were continuously improved.

2 Implementing the constraints of modernization of botanical drug extraction production

2.1 Constraints

2.2 Solutions and effects

Under this circumstance, we have proposed data acquisition and manual control technology solutions, and have gradually applied to traditional production lines, effectively solving many problems and achieving the following effects: (1) Integrating modern management concepts into botanical drug extraction production In modernization cost management; (2) standardize operational documents, improve work efficiency, save energy, reduce consumption, and achieve efficiency; (3) balance the relationship between input and output, and adopt data collection and manual control to avoid excessive investment. , reduce labor costs, reduce labor intensity, reduce management costs; (4) instructions issued by the computer to guide production personnel to strictly follow the SOP, promptly and promptly through the sound and light for errors; (5) after the end of production, the report automatically Printing, not only detailed data of the production process, but also the level of operation of the production staff of this shift.

3 data acquisition, manual control technology in production applications

Data acquisition control system: mainly used to complete process control, it consists of power module, input module, output module, communication module, PLC control cabinet, connection cable, various types of sensing devices. It mainly performs control functions based on control programs such as data display, device status acquisition and processing, and real-time control of switching quantities and analog quantities. FIG. 1 is a schematic diagram of manual control of data acquisition, FIG. 2 is a schematic diagram of a central control, and FIG. 3 is a system framework diagram.

The system adds sensing devices such as flow, temperature, pressure, liquid level and density to the original or newly built equipment and process pipelines, and uses the signals and field indications transmitted from them to prompt the on-site operation to improve the quality of pharmaceutical production. And production to increase production efficiency.

This control technology has been applied to the botanical drug extraction production process and has been well received by users. Moreover, the Shanghai Municipal Science and Technology Commission and the Economic Commission also gave great support to establish a complete set of small plant production test units in our factory. Through continuous exploration and development, it has been effectively implemented in the following production sections:

3.1 extraction

The purpose of this operation is to select a safe and inexpensive solvent, use a small amount of zoi, and extract the active ingredient in the botanical drug to a large extent in a short period of time, while avoiding excessive extraction of the ineffective component.

Confirmation prompt: The database is built in the control system, and the “confirmation prompt” is applied to the non-data processing parameters that affect the product quality and determined by the product process, prompting the operator to check and confirm the relevant content, and whether it meets the process requirements. Such parameters include the specifications of the drug and the method of feeding, the method of extraction, the type of solvent, the number of meshes of the filter screen, and the like.

Time control: The extraction time is a process parameter that has a great influence on the extraction effect and efficiency. The extraction time is clearly defined in the Chinese Pharmacopoeia system. The extraction time can be decomposed into soaking time, heating time, holding time, cycle frequency, and liquiding time. The control system will control and record these times according to the setting requirements.

Temperature control: Extraction temperature is also a process parameter that has a large impact on extraction efficiency and efficiency. During the heating phase, the control system calculates the flow rate of the steam according to the temperature and quantity of the extract before heating, and automatically adjusts the steam flow to increase the temperature to ensure that the heating time is controlled within the process requirements and the heating time is substantially constant for each operation. In case of overheating, the control system automatically collects the extraction temperature and records it, and automatically adjusts the steam flow according to the collected data to control the extraction temperature within the process requirements. In addition, by extracting the condensation effect of the condenser on the tank, the extraction will have an effect when the extraction is carried out under normal pressure and reflux with a certain concentration of ethanol, because if the condensation effect of the condenser is not good, the ethanol will volatilize during the extraction process. The concentration of ethanol in the extract changes. Through the dynamic monitoring of the condensate inlet and outlet temperatures and temperature difference of the heat exchanger, the condensation effect of the condenser is determined, and the basis for the maintenance of the heat exchanger descaling is provided.

Flow control: Install a flow meter on the inlet and outlet pipes of the extraction tank to accurately control and record the amount of solvent and the output of the extract. If the seepage extraction is adopted, the seepage speed can be accurately controlled and recorded by the flow meter; if the double tank dynamic extraction is adopted, the dynamic extraction speed can be accurately controlled and recorded by the flow meter. At the same time, it is also possible to judge the hydrophobic working state by the flow rate on the steam, and use zui good flow production to avoid waste caused by running, running and leaking.

Pressure control: Extracting the heating steam pressure and the pressure inside the tank is also a process parameter that has a great influence on the extraction effect and efficiency. The pressure sensor is installed in the extraction tank and interlocked with the steam flow control system to dynamically monitor and adjust the extraction pressure. Safe production according to the set pressure in the tank to avoid non-safety accidents.

Liquid level control: During the extraction process, according to the material characteristics, the liquid level is controlled to prevent the material from expanding and blocking the secondary steam pipeline, causing the pressure inside the tank to rise. In the dynamic extraction process, the fluid is refilled or discharged by the liquid level command.

Alarm control: During the extraction process, a three-color alarm (yellow prompt, orange warning, red danger and automatic release) is performed on the upper and lower limits of the liquid level, pressure and related parameters in the extraction tank, and the red alarm is determined as an accident.

3.2 Concentration

3.3 rectification

The purpose of this operation is to recover ethanol. To increase the ethanol concentration, Zui greatly reduces the loss of ethanol .

Temperature control: The important parameters affecting the concentration of rectification are the top of the distillation column, the tower section, and the temperature of the column. The influence of the above temperature parameters is the inlet temperature and the inlet flow rate, the steam pressure and flow rate of the heater and the tower, and the condensation cooling effect. The reflux and recovery ratios are automatically adjusted by the change in temperature at the top of the column, and the discharge of the residual liquid is determined by the temperature change of the column.

Pressure control: The steam pressure of the external circulation heater and the tower heater is interlocked with the inlet temperature, the tower temperature and the liquid level. The vapor pressure is controlled by the pressure difference between the top of the tower and the tower to prevent the ethanol from being too fast. Liquid flooding, forming pressure.

Liquid level control: control the liquid level of dilute ethanol and pure ethanol storage tanks, and control the upper and lower limits of the liquid level of the tower to avoid production failures.

Flow control: constant inlet flow rate and recovery/reflux ratio, automatic adjustment of steam flow, ensuring production stability is very critical, flow data collection is also an important basis for cost accounting; through the change of flow can also understand the working state of the relevant valve, to avoid Waste caused by steam leakage, liquid leakage, and blockage.

Alarm control: voice prompts and alarms for setting related parameter flow, liquid level and pressure overrun. The fault implements three-color alarm (yellow reminder, orange warning, red danger and automatic release), and the red alarm is determined as an accident.

3.4 spray drying

4 practical problems solved by data acquisition and manual control technology in production

(1) Scientifically collect and produce relevant data, analyze and summarize the collected signals, and intelligently guide production. Furthermore, the production SOP file will be perfected, the production operation will be standardized, and the data will be explored for each piece of equipment in its work, and the operating procedures will be further standardized. For example, in the production process of the external circulation concentrator ZWN-1000, the working condition of Zui is: the flow rate of the inlet is about 1 100 kg/h (maintaining the same rate of evaporation and evaporation), the inlet temperature is about 90 °C, and the external circulation is heated. The steam pressure is 0.03 MPa, the steam flow is about 550 kg/h, the vacuum is -0.08 MPa, the boiling point temperature of the liquid is 60 °C, and the continuous liquid is continuously concentrated, and the efficiency is high until the concentration of the single-class extract is completed. Then stop the liquid or paste according to the specific gravity of the liquid. The control of the inlet flow rate and steam pressure, flow rate and vacuum degree is the key to determine the normal operation of the equipment. If the liquid level or saponin is too high, there is a running phenomenon. When it occurs, measures must be taken. To return to normal working conditions, it is necessary. For a long time, it can not guarantee the normal use of the equipment, and even cause vicious cycle, vacuum degree, unstable cooling water temperature, prolonged working time, and decreased creaming rate.

(2) It is very important to supervise whether the operator strictly follows the set SOP file operation. Through voice prompts, it guides to correct the operation of the on-site production personnel, solves the shortage of technicians, and avoids the run, run, and leak to the enterprise. loss). For example, using steam equipment for extraction, concentration, etc., the steam flow can determine whether the valve is operating normally. During the use of concentrated ZWN-1000, the steam pressure is close to zero, and the flow rate is more than 600 kg/h. At this time, the computer immediately alarms, and the voice prompts that the valve leaks. After checking the trap of the steam trap, the repair is solved in time, and the maintenance is avoided. Waste of energy.

(3) Employees who take corrective actions or do not follow the voice prompts must be retrained to be employed (targeted by computer data). At the same time, the operator is given a comprehensive evaluation of each class.

(4) Fault alarm: The upper and lower limits of the set range are divided into three-color warning. After the Zui (red) warning, there are safety measures, which can automatically release (pressure relief, overflow) faults and ensure the safety of personnel and facilities. For example, in the extraction process, the tank is produced under normal pressure. At the moment of boiling, there is often a bump to block the secondary steam pipeline, and the equipment is gradually pressurized to form a dangerous operation. At this time, the voice will prompt to stop the steam heating and report to the tank. The pressure has been applied, and the alarm light flashes. It gradually transitions from yellow to orange until it enters red. After entering the red alarm, the tank top is automatically vented, and the computer records the accident once. The manager can call up the production record from the computer at any time to process the accident.

Excerpt from: Li Zhixian. Application of data collection and manual control technology and existing problems. China Pharmaceutical Equipment Magazine [J]. Total 62.2010(10)

Original author profile: Li Zhixian, male, visiting professor, research direction: Chinese medicine engineering and automation