Automation systems in the pharmaceutical industry must not only achieve digital information management, maintain production data integrity, enhance batch-to-batch product consistency, and ensure production record traceability, but also deliver energy efficiency, environmental protection, safety assurance, and technological optimization. By analyzing critical process control points in extraction workshops, the corresponding automation systems play a vital role in managing production processes.
1. Extraction Tank Temperature Control: The extraction process requires uniform and rapid heating of the tank to boiling point, followed by sustained gentle boiling. While temperature probes are commonly used for detection in automated systems, the presence of an outer jacket causes heat transfer delays, potentially leading to imprecise steam regulation. Therefore, steam valves should be moderately opened during the initial heating phase. Once the temperature reaches approximately 90% of boiling point, the steam valves should automatically reduce.
2. Liquid discharge blockage detection: After implementing an automatic control system, monitoring the smoothness of liquid discharge and detecting blockages is critical. Install a pressure transmitter at the outlet of the discharge pump and a flow switch on the discharge pipeline between the tank bottom and the filter. During normal discharge, if the pump outlet pressure drops below a certain value and the flow switch shows no signal, it indicates a blockage at the tank bottom. If the flow switch signals, it indicates a blockage in the filter.
3. Scale buildup on heating tubes in the evaporator. The evaporation process requires high temperatures. Appropriate automated operations can extend the evaporator's service life. Therefore, add water appropriately after double-effect transfer to control cooling, and set automatic liquid replenishment control during evaporation when the liquid level is low.
4. Determining concentration endpoint: When using an online density meter for automatic density monitoring during concentration, the density meter provides relatively accurate readings for pharmaceutical solutions with a concentration density below 1.10 and moderate viscosity. However, when the concentration density exceeds 1.10 and viscosity is high, significant errors may occur. This is because the solution is in a dynamic state during concentration, and certain highly viscous solutions may contain numerous fine bubbles, causing detection errors in the tuning fork probe. In such cases, manual offline density verification is required for determination. If a mass flow meter is used for detection, thorough consideration must be given to cleaning the circulation piping.
5. Control of supernatant discharge from the alcohol precipitation tank. While layered discharge from the tank is difficult to regulate, fixed pipeline positions based on production experience can be established with automated discharge valves. Additionally, install a flowmeter on the main supernatant discharge pipeline to calculate the volume of supernatant discharged.