US 5,104,611 AGranted

Flow blocker for access opening

AssigneeCombustion Engineering, Inc.

InventorsJack L. Woods, Michael D. Turnmire

Life of this patent

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Abstract

A nuclear steam generator 10 with economizer 32 adjacent secondary side feedwater inlets 38a and 38b includes a secondary side divider plate 36 and handholes 40 at opposing 180.degree. locations in alignment with the ends of the plate 36. Notches 42 in the ends of the plate 36 adjacent the aligned handholes 40 facilitate inspection and maintenance access on the secondary side above tubesheet 22. To prevent bypass flow from one side of the divider plate 36 to the other, a novel flow blocker 50 of cylindrical shape is provided for mounting in handholes 40 and notches 42. The flow blocker 50 is defined by telescopically assembled member 52 and 62 which are biased in opposite directions by pre-loaded spring 64 therein to insure stability against vibration and flow induced loads. The flow blocker 50 fits sungly in notch 42 and handhole 40 and is bolted to the inside of closure plate 74 of handhole 40.

Claims12

Dependent claims

In a heat exchanger having a vessel containing a tubesheet which separates a primary side cavity and a secondary side cavity, tubes mounted in the tubesheet in fluid communication with the primary side cavity and extending through the tubesheet and into the secondary side cavity to provide a heat exchanging relationship between fluid in the tubes and fluid in the secondary side cavity, said secondary side cavity including a flow divider plate an having edges attached to the wall of the vessel and extending toward the tubesheet perpendicularly therewith, and a handhole through the vessel adjacent the divider plate perpendicular edges for maintenance and cleaning in the secondary side cavity and a closure plate for the handhole when the heat exchanger is in operation, the improvement comprising:

said divider plate having a notch in said edge,
said handhole being in alignment with said notch,
a flow blocker extending from said handhole into said notch dimensioned such that it substantially fills said handhole and said notch and thereby with the flow divider plate prevents substantial flow from one side of the flow divider plate to the other when the heat exchanger is in operation and such that it can be removed from said vessel through said handhole to permit access to both sides of said divider plate for maintenance and cleaning.

Dependencies are inferred from the claim text.