Research On CAD System Of Chemical Towers Based On Web

Chemical towers are one of the most important equipments in chemical and oil industry. The development of parameterized system for chemical towers plays an important role in the whole chemical machinery industry. According to the currently new achievement in CAD, web-based CAD technology is researched and its structure is analyzed. Hereby the CAD drawing system of chemical towers based on Web is developed . And the key technology of the system is discussed in this paper in detail. The chief achievements and features of this paper are:1. CAD system based on Web. In response to the characteristics of web-based CAD, the key problem is discussed. Combined with the requirement, the implementation of the web-based CAD system is detailedly reported. And three-tier B/S structure based on Web is put forward. The functions are designed and the modules are divided. In this system, remote access and designing parameter disposal are realized because the system website is built by making use of ASP.NET validator controls, data transfer and database operation, etc.2. Chemical towers are developed with ObjectARX. After comparing with several CAD advanced developing tools, ObjectARX2006 is chose in this system. ARX programming environment configuration, basic program structure, graphicsdatabase control and database calling interface and so on are discussed. A series of ARX functions are developed and graphics drawing is achieved. The drawing files are output as *.DWF so that it could be invoked in web pages.3. Modularized and parameterized design. The thoughts of modularization and parametrizing are throughout this system. In view of complexity and expandability, the modules are designed correspond to each parts of a chemical tower so as to reduce the developing difficulty and shorten the project cycle. By the analyses of design parameters, the chief structural parameters are screened out, by which parameterized design can be implemented with engineering database.4. Database technology. Engineering database is set up according to the requirements in order to store design datum and design projects. The modules of data query and modification are developed to maintain and manage engineer datum. ADO is chose as the data access interface based on comparison with many interfaces.5. COM technology. Analyzing the characteristics of COM, the COM register and calling in ASP.NET pages are researched. Then ASP.NET can communicate with AutoCAD by COM.6. Multi-programming technology. In the development process, different programming languages are used in different modules. For example, in parameter input module, ASP.NET page logic is dealt with VB.NET and in drawing module, drawing function is implemented with VC.NET. The system can be developed with great efficiency because several languages can be brought into play in theirs most superiority.The development of CAD system of chemical towers based on Web aims at the requirements of parameterized design with the thought of web-based CAD. It is very important to improve the design level, shorten the design cycle and enhance the competitive power of enterprises so that it is worthy of popularizing in production.