I came across an interesting article from Che.com newsletter. The article caught my attention because it discusses about high-temperature heat-transfer fluid system which is relevant to my plant and work.
Just sharing, the flow of temperature increase in my plant:
1. From feed storage tank
2. Steam heating (50oC) >>
3. Plate Heat Exchanger (105oC) >>
4. Plate heat exchanger (220oC) >>
5. Shell and tube heat exchanger (245oC) >>
6. Oil heater (265oC) >>
7. Plate heat exchanger (180oC) >>
8. Plate heat exchanger (125oC) >>
9. Plate heat exchanger (75oC) >>
10. To product storage tank
The blue Plate heat exchanger and red Plate heat exchanger, shows the same heat exchanger exchanging heat between colder oil and hotter oil.
Shell and tube, and oil heater are able to heat up the oil above 240oC because it uses a closed system steam circulation from a high pressure boiler operating at pressure above 40oC.
Summary of the article from Che.com newsletter:
Fluid selection, system design and maintenance are the keys to achieving the best performance
By Krishnan Sahasranaman - Uhde India Ltd.
Although water and steam are the ideal media for heat transfer, there are often situations when other heat-transfer fluids are called upon to perform this function in the chemical process industries (CPI). Thus there are, at the very high-temperature end, various types of heat-transfer fluids, such as molten salts and even molten metals. At the lower end of the temperature scale we have various proprietary and non-proprietary brines, usually glycols of one kind or the other. Between these two temperature extremes, a variety of heat-transfer fluids are also available. For this discussion, the focus will be on high-temperature heat-transfer fluids; those having useful bulk-fluid-operating temperatures of approximately 70–400°C.
For high-temperature operation, heat-transfer-fluid systems have distinct advantages when compared to steam or direct-fired heating. For example, using steam for process heating to temperatures in excess of 225°C would require steam pressures upwards of 40 bars. For the same application, the use of a heat-transfer-fluid system would thus eliminate the need for costly high-pressure equipment and piping, expensive boiler-feed-water treatment, and specially trained boiler operators. And compared to direct-fired heating, the use of heat-transfer fluids allows the heater to be safely located away from the process and reduces the danger of forming hot spots in the process itself.
An engineer likely to be involved with high-temperature heat-transfer fluids should be familiar with the types of fluids available, and how to choose among them. It is also important to be aware of the design guidelines for the components of a heat-transfer-fluid system, and the problems that can arise with them.
Read this article and the entire newsletter HERE.