Nozzle design for high temperature attemperators

摘要

An improved spray nozzle assembly for use in a steam desuperheating device that is adapted to spray cooling water into a flow of superheated steam. The nozzle assembly is of simple construction with relatively few components, and thus requires a minimal amount of maintenance. In addition, the nozzle assembly is specifically configured to, among other things, prevent thermal shock to prescribed internal structural components thereof, to prevent “sticking” of a valve element thereof, and to create a substantially uniformly distributed spray of cooling water for spraying into a flow of superheated steam in order to reduce the temperature of the steam.

主权项

1. A nozzle assembly for a desuperheating device configured for spraying cooling water, the nozzle assembly comprising:
a nozzle housing defining a seating surface and having a flow passage extending therethrough; a valve element movably attached to the nozzle housing and selectively movable between closed and open positions relative thereto, a portion of the valve element being seated against the seating surface in a manner blocking fluid flow through the fluid passage and out of the nozzle assembly when the valve element is in the closed position, with portions of the nozzle housing and the valve element collectively defining an outflow opening which facilities fluid flow through the flow passage and out the nozzle assembly when the valve element is in the open position; a nozzle shield movably attached to the nozzle housing and cooperatively engaged to the valve element such that the movement of the nozzle shield facilitates the concurrent movement of the valve element; and a biasing spring disposed within the nozzle shield and cooperatively engaged thereto, the biasing spring being operative to normally bias the valve element to the closed position, the nozzle shield and the biasing spring having dissimilar shapes; wherein the nozzle shield is sized and configured such that the biasing spring disposed therein is effectively shielded from direct impingement of cooling water flowing into the flow passage.