A heat transfer system includes a plenum configured to provide a secondary side fluid such as feedwater to a plurality of heat transfer tubes from a primary side fluid, and a tube sheet coupled to the plurality of heat transfer tubes. An orifice plate is mounted within the plenum and located adjacent to the tube sheet, and one or more orifice devices are supported by the orifice plate and are configured for insertion into or sealing against the plurality of heat transfer tubes. The one or more orifice devices may include center flow orifices, and/or rectangular or helical shaped transition stepped annular flow orifices, and an insertion of a number of the transition steps into the plurality of heat transfer tubes may determine a corresponding pressure drop of the secondary side fluid in the heat transfer system.

A heat transfer system includes a plenum configured to provide a secondary side fluid such as feedwater to a plurality of heat transfer tubes from a primary side fluid, and a tube sheet coupled to the plurality of heat transfer tubes. An orifice plate is mounted within the plenum and located adjacent to the tube sheet, and one or more orifice devices are supported by the orifice plate and are configured for insertion into or sealing against the plurality of heat transfer tubes. The one or more orifice devices may include center flow orifices, and/or rectangular or helical shaped transition stepped annular flow orifices, and an insertion of a number of the transition steps into the plurality of heat transfer tubes may determine a corresponding pressure drop of the secondary side fluid in the heat transfer system.

A throttle device for varying the pressure of a fluid in a plurality of parallel outlets includes a fluid collector having at least an internal chamber, an inlet and a plurality of outlets for the fluid, and a control element displaceably mounted in the internal chamber of the fluid collector and comprises a plurality of orifices, the cross-section of which can be varied by a relative movement of the control element in relation to the fluid collector. The control element is a sleeve, wherein the orifices are disposed in the sleeve such that they correspond to the outlets of the fluid collector, wherein between the sleeve and the fluid collector seals are provided, such that in a region between of an outside surface of the sleeve and an inside surface surrounding the internal chamber of the fluid collector no fluid communication takes place between the orifices of the sleeve.

A throttle device for varying the pressure of a fluid in a plurality of parallel outlets includes a fluid collector having at least an internal chamber, an inlet and a plurality of outlets for the fluid, and a control element displaceably mounted in the internal chamber of the fluid collector and comprises a plurality of orifices, the cross-section of which can be varied by a relative movement of the control element in relation to the fluid collector. The control element is a sleeve, wherein the orifices are disposed in the sleeve such that they correspond to the outlets of the fluid collector, wherein between the sleeve and the fluid collector seals are provided, such that in a region between of an outside surface of the sleeve and an inside surface surrounding the internal chamber of the fluid collector no fluid communication takes place between the orifices of the sleeve.

A steam direct injection injector and direct injection heater assembly. The injector defines an enclosure having an upstream end that is constructed to receive a steam fluid flow and a plurality of radially oriented orifices that are configured to distribute and inject the steam into a surrounding fluid. A seat is disposed proximate a downstream end of the injector and a movable plug or modulating component is disposed within the enclosure proximate the seat. A biasing element is disposed between the seat and the modulating component and configured to interact with the seat and the modulating component to allow selective exposure of a second heating section without obstructing a first heating section that are defined by the radially oriented orifices of the injector.

A steam direct injection injector and direct injection heater assembly. The injector defines an enclosure having an upstream end that is constructed to receive a steam fluid flow and a plurality of radially oriented orifices that are configured to distribute and inject the steam into a surrounding fluid. A seat is disposed proximate a downstream end of the injector and a movable plug or modulating component is disposed within the enclosure proximate the seat. A biasing element is disposed between the seat and the modulating component and configured to interact with the seat and the modulating component to allow selective exposure of a second heating section without obstructing a first heating section that are defined by the radially oriented orifices of the injector.