Development Of CAD System For Quick-opening Supercritical Extraction Kettle

Supercritical fluid extraction (SFE) mostly adopts semi-batch operation under high pressure. Extracted materials need to be exchanged frequently, and extraction kettle also needs to be rinsed, therefore the characteristic of SFE requires that the extraction kettle should adopt quick-opening seal structure. Due to the complication of quick-opening seal structure and stresses, there is no accomplished standard to follow at present. Based on the design status of the quick-opening seal structure of SFE kettle, and applied with object oriented approach as well as process oriented approach, the CAD system for SFE kettle is designed and developed. Thus, design calculation and assembly drawing of SFE kettle can be achieved automatically. The CAD system for SFE kettle is studied based on AutoCAD exploiting technology of ActiveX Automation on Visual Basic6.0 platform and under AutoCAD2002 drawing environment. The parametric design technology and Microsoft Office software are used in the system. The main contents are as follows. 1. Japanese Industrial Standard JIS B 8284-2003 and the quick-opening seal structure designed by Nanjing University of Technology are referred in the thesis. Strength calculation program for quick-opening seal structure of extraction kettle is compiled according to the calculation method referred above. Based on JB 4732-95 "Steel Pressure Vessels—Analysis and Design Standard", strength calculation program for the shell and flat head is compiled. 2. Based on JB 4732-95 "Steel Pressure Vessels—Analysis and Design Standard", the fatigue analysis program for the stress concentration areas of quick-opening seal structure is compiled. System provides the accumulative damage analysis program of the SFE kettle where there are fatigue loads. 3. In terms of the characteristics of SFE kettle, the parametric design of part drawing and the assembly drawing of SFE kettle are obtained through classification parametric drawing strategy. Outer-boundary of the drawing is obtained from regions established through ActiveX technology and then the hidden lines are removed through extended command Wipeout of AutoCAD. Thus, a new method of removing hidden lines is put forward. 4. Applied Microsoft Access 2002 as DBMS (Database Management System), ADO (ActiveX Data Object) Data control and combined with SQL (Structured Query Language), Data inquiry and data update are achieved. Based on ActiveX Word technology and Microsoft Word 2002, the corresponding computational book is established. 5. The CAD system for SFE kettle uses HTML Help Workshop to make the online help file. Applied with program technology, such as menu selection and error check and information tips etc, excellent UGI (User Graphic Interface) is provided. Installation program of CAD system is compiled through Setup Factory7.0. Based on the design technologies above, the CAD system for SFE kettle is developed. The design cycle of the extraction kettle can be shortened and the design efficiency can be enhanced. The CAD system for SFE kettle can achieve the design calculation and assembly drawing of SFE kettle automatically. Therefore, the CAD system for SFE kettle is of engineering application value.