Operation, Maintenance and Future Technical Development of TQ-D Inverted Cone Extraction Tank

1. Overview

The TQ-D inverted cone extraction tank is a core process equipment for the extraction of active ingredients from plants. It is widely applied in traditional Chinese medicine, natural extract, functional food, fine chemical and other industries, and supports multiple processes including water decoction, warm immersion, thermal reflux, forced circulation percolation, volatile oil collection and organic solvent extraction. Adopting an inverted cone structure with a smaller upper section and a larger lower section, the equipment features a sufficient effective flow cross-section at the tank bottom. Combined with a detachable double-layer filter plate structure, it effectively reduces fluid short-circuiting and filter blockage risks, delivering outstanding advantages in residue discharge and liquid outlet working conditions. Equipped with a honeycomb jacket heat exchange system, built-in CIP rotary spraying device, condensation recovery unit and pneumatic quick-opening residue discharge mechanism, the tank complies with GMP clean production specifications and has become one of the mainstream equipment for batch extraction production lines. The long-term stable operation of the equipment relies heavily on a standardized maintenance system. Meanwhile, with the upgrading of intelligent manufacturing and green production in the industry, the equipment structure, control logic and process adaptability are continuously iterated and optimized.

2. Graded Maintenance Specification for TQ-D Inverted Cone Extraction Tank

The operation and maintenance work follows a three-level management principle of daily inspection, periodic maintenance and shutdown overhaul. Centering on cleaning management, sealing protection, heat exchange system maintenance, and automatic control and safety device verification, it eliminates typical hidden dangers such as material residual corrosion, liquid leakage, heat exchange attenuation and safety accessory failure.

2.1 Daily Maintenance (Per Shift)

2.1.1 Cleaning System Maintenance

Cleaning operations shall only be carried out after full pressure relief and temperature reduction upon production completion. Empty the tank residues and flush the inner tank wall, feeding port, sight glass and inner side of the residue discharge door via the built-in CIP rotary spray ball. Focus on cleaning the gaps of the bottom double-layer filter plate and residues in the liquid outlet pipeline to prevent coking and carbonization of plant residues which may scratch the passivation film of the stainless steel body. Hard tools are prohibited from scraping the polished surface of the tank to avoid micro-pits on the inner wall that cause material adhesion. For alcohol extraction processes, special adaptive cleaning agents shall be used for circulating cleaning to remove resin and grease residues. The tank shall be fully ventilated and dried after cleaning to reduce pitting corrosion caused by humid environment inside the tank.

2.1.2 Inspection of Sealing and Transmission Components

Visually inspect the sealing ring of the residue discharge door, flange gaskets and pipe joints for liquid leakage, aging, hardening and cracking. Check the opening and closing stability of the pneumatic cylinder to ensure no jamming or abnormal noise. The feeding door and residue discharge door are forbidden to open under pressurized working conditions. Residual pressure in the pneumatic system shall be released in a timely manner after shutdown to avoid accelerated aging of sealing rings caused by long-term continuous pressure.

2.1.3 Inspection of Instruments and Safety Devices

Verify the readings of local pressure gauges, temperature sensors and vacuum gauges to ensure no obvious deviation. Check the integrity of sight glass for cracks and leakage. Confirm the intact appearance of safety valves and explosion-proof membranes with unobstructed discharge channels. Monitor the working condition of the jacket steam trap during operation to prevent reduced heat exchange efficiency and local overheating of the tank caused by poor drainage.

2.1.4 Inspection of Pipelines and Auxiliary Units

Ensure stable supply of circulating medium for condensers and coolers and normal opening and closing of all valves. Monitor the operation vibration and noise of the circulating liquid pump, and confirm no distortion or tensile stress at flexible pipeline connections.

2.2 Periodic Maintenance (Weekly & Monthly)

2.2.1 Weekly Maintenance

Apply food-grade lubricant to the hinge points and rotating shafts of pneumatic actuators. Unclog CIP spray nozzles to avoid cleaning dead angles caused by residue blockage. Thoroughly clean internal deposits of the defoamer to prevent condensate system pollution caused by material entrainment in secondary steam.

2.2.2 Monthly Primary Maintenance

Dismantle the bottom double-layer filter plate to thoroughly clean blocked filter holes and check for filter plate deformation and perforation. Fully inspect the operating status of jacket steam pipelines, steam traps and drain valves, and remove scale inside the jacket. Calibrate the zero point of on-site temperature and pressure instruments. Investigate potential leakage risks at all welded joints and flange sealing surfaces. Fasten electrical terminal connections.

2.3 Annual Shutdown Overhaul

Fully disassemble and inspect the welding seams and inner passivation layer of the tank, and perform polishing repair if necessary. Evaluate and replace all sealing parts as required. Send safety valves and pressure gauges for statutory metrological verification. Overhaul and descale condensation and cooling heat exchange tube bundles to restore heat exchange efficiency. Conduct full functional tests on PLC modules, sensors and actuators of the automatic control system. Inspect the grounding and anti-static system, which is particularly critical for alcohol extraction working conditions.

2.4 Preventive Management of Typical Faults

Common faults during long-term operation mainly include residue door leakage, filter plate blockage, reduced heat exchange efficiency and failed spray cleaning. It is recommended to establish a spare parts list for vulnerable components including sealing rings, filter plates, spray balls and pneumatic parts. Formulate differentiated cleaning schemes according to the characteristics of water extraction and alcohol extraction materials. Implement thorough cleaning between production of different materials to avoid cross-contamination.