Simple way to detect continuous lines
I have two methods to suggest:
1. Use the erosion (morphological operator) (you can also use other operators like closing/opening). But i think it will destroy the steam data also...
2. A better solution is to detect the lines using hough transform. Google it and you'll find tons of info about it (if your'e using MATLAB, there is a guide how to do it in their website)

Have fun...