Regarding heat exchanger selection
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I recently encountered a problem related to the selection of heat exchangers. The main issues and relevant parameters are as follows; I would appreciate it if experts could help me figure this out. 1. This heat exchanger is primarily used for preheating materials; the materials flow through the tube side, with an inlet temperature of 30–45°C and an outlet temperature of 70°C. The material flow rate is 15–20 m3/h, and the pressure is 0.4–0.6 MPa. 2. Steam is used in the shell side, with a steam pressure of 1.0 MPa. Because the raw material itself contains an acid value. (Chloride ions, generally within 10 ppm). The material is fed into the heat exchanger intermittently, usually three times a day for 4 hours each time. Due to the properties of the material itself, carbon steel cannot be used as the material of construction. Based on the above characteristics of equipment trials, I would like to ask the experts how to choose this heat exchanger.
Saturated steam at 1 MPa is around 170-180°C, I think
This post was last edited by CHANGBAISHI on 2020-6-28 06:29. Could steam be used to heat water first, and then that water be used to heat the material? Such heat exchange makes it easier to control the temperature and results in greater stability. Make a large tank with coils inside, through which the material flows. Steam is introduced at the bottom of the tank through small holes, allowing the steam to distribute evenly and heat the water. At the highest point, an overflow discharge pipe chassis is installed along with connection pipes, along with a valve for draining liquid. Oh, add a level gauge to it. When in use, fill the tank with water, open the steam valve to heat the water, and then feed in the material. This can be made using stainless steel pipes; it’s worth giving it a try.
Steam at 1 MPa is reduced to 0.3–0.4 MPa by a self-acting pressure regulator before entering the steam distribution cylinder; from there, it flows through a control valve into the shell side of the heater. The recommended model for this heater is the YKC type round-hole graphite heat exchanger. The material flows through the tube side, and a thermocouple is installed at the material outlet to monitor its temperature, generating a 4–20 mA DC signal. This signal is used to control the opening degree of the control valve at the steam inlet on the shell side, thereby regulating the temperature at the material outlet. The temperature control of this device is not complicated; precise temperature control can be easily achieved by adjusting the valve. The selection of equipment gives top priority to corrosion prevention in the tube side. The block-hole graphite heat exchanger possesses an excellent resistance to chloride ion corrosion; this type of heat exchanger can be used for extended periods at the boiling point of hydrochloric acid at any concentration without experiencing any corrosion. Feel free to contact me if you would like to discuss further.
Laser fully welded plate heat exchangers can fully meet the operating conditions of your application.
Will titanium heat exchangers work? What about the type of tube bundle?
It is recommended to use a shell-and-tube heat exchanger; if the viscosity is high and the fluid has low acidity, 316L material can be used for the tube side while carbon steel can be used for the shell side. However, given the high temperature of your steam, local overheating may occur, so it might be advisable to use steam at a lower temperature or secondary hot water. The required area is approximately 120, based on 1.0 unit of steam