BST (Batch Stirred Tank)
 | Purpose of the program |  |
The Batch Stirred Tank (BST) program is a component of the software for assessment of thermal hazards of chemical processes. It is intended for computer simulation of physical and chemical processes in well-stirred batch tanks with emergency pressure relief systems and calculation of a proper size of a vent system that provides prevention of tank bursting in case of a runaway reaction. The DIERS methodology is used for simulation of gas-liquid mixture flowing out of the tank. | Storing data | |
BST allows saving projects. Every project includes all the information prepared for simulation - kinetic model, operational conditions, and physical properties of a substance. Project can also include results of simulation in graphic form. | Type of kinetic models | |
BST allows application of both formal and descriptive models. A model can be loaded from the ForK/DesK database or created by using facility of BST. | Type of reactor's models | |
A reaction is considered to proceed in a well stirred batch reactor. The following shapes are available: - horizontal finite cylinder;
- sphere;
- vertical cylinder with limited length (barrel).
| Boundary conditions | |
Heat exchange with environment is defined as a function of time and includes: - convective heat transfer according to Newtonian law;
- radiational heat transfer according to Stephen law;
- heat flux on the outer surface.
| Flow models in a reactor | |
BST provides simulation of the following types of in-tank flow models: - bubble;
- churn turbulent;
- foam.
| Type of emergency relief system | |
BST provides simulation of 3 sectional vent system consisting of entrance pipe, venting device (nozzle), and tail pipe. The following options are available: - venting device type: rupture disk or valve;
- vent position: top or bottom;
- pipes inclination can be defined.
| Flow models in the relief system | |
The following flow models in the vent system are available: - one phase - liquid or gas;
- two phase:
- homogeneous equilibrium or frozen for nozzle;
- homogeneous equilibrium or non-equilibrium for pipes.
| Database of physical-chemical properties | |
BST has internal database physical-chemical properties which provides calculation of properties for ideal and non ideal multi component reacting mixtures. The database includes two parts: reference Data Bank and prognostic module. Reference data bank contains complete sets of properties for more than 300 substances. Prognostic module ensures estimating unknown physical properties using a minimal set of experimental data. | Simulation modes | |
The following modes of simulation are envisaged in BST: - runaway;
- vent sizing (optimizing the nozzle diameter);
- blowdown.
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