Pre-Startup Preparation
Before starting the plate heat exchanger, ensure that the permitted pressure and temperature indicated on the nameplate are not exceeded. If temperature and pressure exceed the limits, safety measures must be taken. Before restarting the device after maintenance or long shutdown, check whether the dimensions and consistency of all fastening bolts meet the requirements. To avoid pressure shocks when starting and shutting down the heat exchanger, corresponding components should be installed to minimize generated pressure shocks.
After long-term use, during the startup and shutdown stages, when the heat exchanger is in a cold state, especially when using compressed fiber gaskets, leakage may occur. This leakage will decrease as the temperature rises, which is a natural phenomenon for gaskets. Before processing any new medium different from the original design, all components that will contact the medium such as gaskets, heat exchange plates, and connectors must be tested to determine suitability.
Startup Procedure
Begin by closing the feed pipe valve if no volumetric pump is installed, and open the circuit valve if present. Open the exhaust valve if equipped. After checking all valve positions, turn on the pump. Slowly open the inlet to prevent pressure shocks. After all air has been expelled from the plate heat exchanger, close the exhaust valve. Before fully opening the inlet, verify that all air has been completely expelled from the heat exchanger.
It is recommended to start the side containing the medium with the lower processing temperature and pressure first. For cold pressure circulation, if the temperature of the cooling medium is below the freezing point, the medium to be processed should be loaded into the heat exchanger first to prevent the device from freezing. The order of product entry should be chosen so that uncontrollable evaporation does not occur. Volumetric pumps must be started gently to avoid damaging pressure surges.
Shutdown Procedure
When shutting down, slowly close the valve of the product inlet pipe. Only after the product inlet pipe valve is completely closed can the pump be turned off. Repeat these steps on the other side of the device. Close the circuit valve. Before long-term shutdown, thoroughly clean the plate heat exchanger to minimize corrosion damage. It is recommended to loosen the tightening force within the heat exchanger and only re-tighten the device just before returning to operation.
Safe Operation Practices
When working temperature, pressure, or product inlet flow rate must be changed, adjustments should be made slowly and over an extended period. Frequent pressure changes, even of small magnitude, may affect gasket service life. Extreme temperature changes from a hot state to a fully cold state should be avoided as this accelerates gasket aging. To reduce pressure and extend gasket service life, additional spring connection assemblies can be installed in the connecting rods.
The user is responsible for ensuring that if a new product is introduced, it will not chemically or thermally react with previously processed fluids remaining in the device. If such a reaction is possible, the fluid in the device must be thoroughly drained before pumping in the new fluid.
