Oil can be of various kinds, but the most popular are:
- diesel oil;
- industrial oil;
- transformer oil;
- compressor oil.
The oils are usually produced by mixing (compounding) of basic distilled oils with each other or with residual components. To improve the product, additives are required. The amount of additives varies from 3 to 17%. Oil refining specialists consider mixing the most important process in the final stage of oil production.
There are the following types of mixing:
- batch mixing;
- partial inline mixing;
- continuous inline mixing.
Batch mixing is one of the oldest methods. It involves pumping components into a tank and circulating them until a uniform product is obtained. After the viscosity of the oil is as required, additives are introduced and the mixture is circulated through a heater for 6-8 hours.
This method is rather ineffcient and is only used by facilities which produce a limited range of oil products.
Partial inline mixing is injection of all components in certain ratios. This technique is good for production of oils with few components.
Continuous inline mixing is highly efficient, due to the use of automated mixing units. All components are supplied into the pipeline according to a formula and turn into high quality oil product in the collector.