We are facing problem of low heat duty of the debutanizer reboiler. Tube side heating media is saturated high pressure steam. Our steam flow was decreased gradually. We opened steam flow supply valve more to increase the heat duty, but still we did not succeed. We use saturated high pressure steam as heating medium and operating temperature is 482 Deg F (250 C). We as of now ruled out the reason of polymerization because of the low heating medium temperature, but question is that higher shell side tube wall temperature due to low pressure drop and it may lead into polymerization. Can it happen?
One more point is that, we have one online sealing clamp at steam inlet line and we injected sealing material three times to arrest leak. I thought that this sealing material might have blocked the control valve upstream cadge/ filter and reduce the steam flow. We had reduced the condensate pot pressure and we observed that the steam flow was increased.
What can be the reason for low reboiler heat duty? Is it because of polymerization or chocking of the steam control valve? How can we conclude this problem?