Heat recovery boiler with induced circulation

Process for employing a boiler comprising one or more steam generating circuits, optionally at different pressures, each comprising a water/steam separating flask, an evaporator device with finned pipes, arranged horizontally in a stream of hot gases, downcomer and riser pipes ensuring the communication between the flask and the evaporator device via an entry manifold and an exit manifold, at least one steam generating circuit comprises an ejector capable of ensuring an induced water circulation in the boiler in normal operation, and in that the corresponding water/steam separating flask is arranged at any height in relation to the exit manifold of the evaporator device of this circuit, said process comprising the following stages:

• introducing water into the evaporator device and the flask of at least one steam generating circuit, by means of a feed pump, this being done up to a starting-up level;
• actuating a means for ensuring a minimum flow rate permitting the operation of the ejector during the starting-up stage;
• heating the boiler;
• setting the feed pump in motion again so as to allow the ejector to ensure the induced circulation during the normal operation of the boiler;
• and
• introducing a movable needle during the starting-up stage into a part of the ejector and in that it is actuated to control the flow rate of the water.

Heat recover boiler comprising one or more steam generating circuits, optionally at different pressures, each comprising

• a water/steam separating flask,
• an evaporator device with finned pipes, arranged horizontally in a stream of hot gases,
• downcomer and riser pipes ensuring the communication between the flask and the evaporator device via an entry manifold and an exit manifold,
• at least one steam generating circuit comprises an ejector capable of ensuring an induced water circulation in the boiler in normal operation, and in that the corresponding water/steam separating flask is arranged at any height in relation to the exit manifold of the evaporator device of this circuit, and
• each ejector being equipped with a movable needle at its conical nozzle.

Heat recovery boiler comprising one or more steam generating circuits, optionally at different pressures, each comprising

• a water/steam separating flask,
• an evaporator device with finned pipes, arranged horizontally in a stream of hot gases,
• downcomer and riser pipes ensuring the communication between the flask and the evaporator device via an entry manifold and an exit manifold,
• at least one steam generating circuit comprises an adjustable ejector capable of limiting the flow rate of the driving fluid during the starting-up stage and of ensuring an induced water circulation in the boiler in normal operation, and
• each steam generating circuit comprising an ejector additionally comprises a means for ensuring a minimum flow rate permitting the operation of this ejector during the stage of starting up the boiler.

Process for employing a boiler comprising one or more steam generating circuits, optionally at different pressures, each comprising a water/steam separating flask, an evaporator device with finned pipes, arranged horizontally in a stream of hot gases, downcomer and riser pipes ensuring the communication between the flask and the evaporator device via an entry manifold and an exit manifold, at least one steam generating circuit comprises an adjustable ejector capable of limiting the flow rate of the driving fluid during the starting-up stage and of ensuring an induced water circulation in the boiler in normal operation,

• introducing water into the evaporator device and the flask of at least one steam generating circuit, by means of a feed pump, this being done up to a starting-up level;
• actuating a means for ensuring a minimum flow rate permitting the operation of the ejector during the starting-up stage with minimum adjustment;
• heating the boiler;
• setting the feed pump in motion again so as to allow the ejector to ensure the induced circulation during the normal operation of boiler;
• and
• introducing a movable needle during the starting-up stage into a part of the ejector including a conical nozzle and in that it is actuated to control the flow rate of the water.

Heat recovery boiler comprising one or more steam generating circuits, optionally at different pressures, each comprising

• a water/steam separating flask,
• an evaporator device with finned pipes, arranged horizontally in a stream of hot gases,
• downcomer and riser pipes ensuring communication between the flask and the evaporator device via an entry manifold and an exit manifold,
• at least one steam generating circuit comprises an adjustable ejector capable of limiting the flow rate of the driving fluid during the starting-up stage and of ensuring an induced water circulation in the boiler in normal operation, and
• each ejector being equipped with a movable adjustment needle at its conical nozzle.