Steam generator with pre-heating
AssigneeFramatome
InventorJean-Claude Yazidjian
Life of this patent
Estimating the term…
Abstract
A steam generator having cold branch and hot branch zones defined, inside the secondary envelope, by vertical partitions separating the cold limbs from the hot limbs, and outside the secondary envelope by a skirt surrounding a portion of the latter on the cold branch side, forming therewith a space closed on its sides and at its lower portion while leaving a passage to the cold branch zone from the inside of the envelope. The space is open at the top so that recycled water can return to the bundle of U-tubes through both zones, but secondary feed water circulates for the most part in the cold branch zone. Recycled water may be distributed between the cold and hot branch zones, and the pressure in these zones may be balanced at the level of a horizontal, perforated tubular plate.
Claims12
Steam generator comprising
- (a) a pressure resistant, cylindrical outer vessel with a vertical axis;
- (b) an upper dome and a lower dome closing said vessel at each end thereof;
- (c) a horizontal tubular plate arranged inside said vessel, fast to the latter and defining with said lower dome a chamber separated into an intake manifold and a discharge manifold, respectively, for heat transfer primary fluid;
- (d) a bundle of U-tubes mounted on said tubular plate, each having a hot limb which communicates with said intake manifold and a cold limb which communicates with said discharge manifold, the group of hot limbs constituting a hot arm and the group of cold limbs constituting a cold arm;
- (e) a secondary envelope engirdling said tube bundle without being supported on said tubular plate and defining an annular space with said outer vessel;
- said intake device for feeding said annular space with secondary water intended to reascend along tubes of said bundle and to be vaporized on contact therewith;
- and,
- (g) in the upper portion of said vessel, a group of separators and an opening formed in said upper dome for the removal of the steam produced;
- (h) said steam generator being separated into a cold arm zone and a hot arm zone, the separation being effected inside said secondary enevelope by a vertical partition separating said hot limbs from said cold limbs, and outside said secondary envelope by a skirt encircling a portion of said secondary envelope on the side of said cold arm and constituting with said envelope line a spaced closed on the sides and at its lower portion, while leaving a passage to said cold arm zone from the inside of said envelope, and open at its upper portion, so that the secondary water recycled after passage in said separator can return to said bundle of U-tubes through both said cold arm zone and said hot arm zone, but that the secondary feed water, arriving through said intake device situated at the upper portion of said generator, flows for the essential part of its flow, in said cold arm zone.
Dependencies are inferred from the claim text.