To meet industry demands for high-pressure operation and frequent start-up/shutdown cycles in supercritical fluid extraction equipment, a novel quick-opening structure integrating dual sealing and a manual safety interlock has been successfully developed. This design directly addresses long-standing shortcomings of traditional quick-opening devices, such as complex operation and unreliable sealing, providing crucial technical support for the wider application of supercritical technology in the petroleum, chemical, food, and pharmaceutical industries.
Supercritical fluid extraction is a highly efficient separation and purification technology. Its significant advantages-including rapid mass transfer, high efficiency, low temperature, and clean media-have made it a key method for obtaining high-quality products across many sectors. However, this technology operates under high pressure and typically uses a batch or semi-continuous mode, requiring frequent material changes and repeated opening, cleaning, and closure of the vessel. This places severe demands on the sealing performance, operational efficiency, and safety reliability of the quick-opening device.
While the clamp-type quick-opening devices commonly used today are structurally simple and suitable for a wide pressure range, they have notable drawbacks. Traditional designs employ a double-conical inner wall, requiring operators to tighten or loosen multiple bolts and reposition the clamp segments individually-a time-consuming process that prevents truly rapid operation. To overcome this, the R&D team proposed a new structural solution with core innovations in three areas:
Opening/Closing Mechanism: The new design innovatively uses a hand-cranked screw to drive the clamp's sliding motion. The screw features left-hand and right-hand threads at opposite ends, engaging with internal threads on the two clamp segments. Rotating the handle causes both segments to slide synchronously in opposite directions along the support rods, achieving rapid engagement or disengagement. This significantly reduces opening and closing time. The design also eliminates the need for a conical inner wall on the clamp. Consequently, the sealing preload is no longer dependent on the clamp geometry, reducing operator effort and simplifying clamp manufacturing.
Sealing System: The structure employs a dual O-ring seal arrangement. Sealing rings are installed at the bottom flange of the top cover and the top face of the vessel flange, providing two sealing barriers. When internal pressure rises, the support ring moves upward, automatically compressing the cover's lower sealing ring. This creates a self-energizing sealing effect, further ensuring reliability under high pressure.
Safety Design: An integral manual safety interlock ensures full-process safety control, preventing pressurization unless closed and preventing opening while pressurized. The interlock base is welded to the outer wall of the vessel. Its connection point is fitted with a ball valve and an audible alarm. A positioning pin moves axially with the operation of the ball valve handle, engaging or retracting from a hole in the clamp. If the clamp is not fully closed, the pin cannot engage, the ball valve cannot be closed, and the vessel cannot be pressurized. To open the vessel, the ball valve must first be opened to vent residual pressure; the alarm will sound until pressure is fully relieved. Only then can the clamp be disengaged and the cover opened, fundamentally eliminating safety risks from operator error.
Compared to traditional designs, this new quick-opening structure offers distinct advantages: the dual-seal design with a self-energizing mechanism improves sealing reliability; the screw-driven mechanism greatly enhances opening/closing efficiency; and the safety interlock provides robust operational protection. The overall design is flexible and reliable, with low manufacturing cost and long service life, fully meeting the practical requirements for manual operation.
Industry experts note that the successful development of this new quick-opening structure effectively solves a core industry challenge: the frequent opening and closing of supercritical fluid extraction equipment under high pressure. It not only improves equipment utilization and reduces non-productive time but also enhances the safety of the entire production process. This lays a solid equipment foundation for the broader promotion and application of supercritical fluid extraction technology. As this structure sees industrial adoption, production efficiency and product quality in related sectors are expected to improve concurrently.