Vahterus Plate - Page 18

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Fig. 1. When the rate of temperature increase is higher than 5°C/minute, the time between the
incremental steps has to be taken into account.
Steam generator:
1. Checkthatthe heatexchangercoldsideisoodedwiththecondensatebefore
openingthesecondarysideow.
2. First, open the hot side to start heating up. Open the valve gradually to prevent
thermal shocks.
3. Open the inlet valve of the primary side, allowing liquid to enter the generator.
After that, open the outlet valve (start-up valve if any).
4. Iftheunitiscold,thecorrectheatingspeedis100°C/hourfortherst100°C.After
that, the heating rate can be doubled.
5. Gradually continue opening the hot/cold side valves to reach the required capacity.
Shut down:
If the process is to be stopped, begin shutting down the hot side following the steps
below, then repeat the same for the cold side.
1. Slowlyclosetheinletvalves.Graduallydecreasetheowuntilitstopscompletely.
2. Switchothepumps.
3. Close the outlet valve.
4. Drain and vent the heat exchanger.
Fig. 2. When the rate of temperature increase is lower than 5°C/minute, the temperature can
be increased immediately after it has reached the adjusted temperature.