A shell-and-tube heat exchanger comprises a shell enclosing a plurality of U-shaped tubes. Each tube is provided with a first portion and with a second portion. The open ends of each tube are connected to a tube-sheet. A pressure chamber is connected to the tube-sheet. The pressure chamber contains a guiding jacket that, at a first end thereof, is sealingly joined to the tube-sheet or the first tube portions and, at a second end thereof that is opposite to the first end, is open. The guiding jacket splits the pressure chamber into a first section and a second section. The first section and the second section are in communication with each other by means of the open end of the guiding jacket. The first section is provided with a liquid level, located below the open end, and therefore with a vapour chamber, located above the liquid level.

An evaporator system for an industrial boiler, containing a heat transfer system, a separator for separating water and steam and a dryer for drying the separated wet steam. A horizontal vessel contains a required minimum amount of water, a relatively small steam volume and internals for the separation of water and wet-steam. A vertical vessel contains internals for drying the wet steam to predetermined values by separating liquid from the wet-steam. The horizontal vessel and the vertical vessel are connected to each other by wet-steam piping through which separated wet-steam is transported from the horizontal vessel to the vertical vessel. The vertical vessel has a connection to dry-steam piping for discharging dried steam. The vertical vessel has a connection to a liquid drain piping for transporting liquid from the vertical vessel back to the inlet conduits of the evaporator heat transfer section.

A shell-and-tube heat exchanger comprises a shell enclosing a plurality of U-shaped tubes. Each tube is provided with a first portion and with a second portion. The open ends of each tube are connected to a tube-sheet. A pressure chamber is connected to the tube-sheet. The pressure chamber contains a guiding jacket that, at a first end thereof, is sealingly joined to the tube-sheet or the first tube portions and, at a second end thereof that is opposite to the first end, is open. The guiding jacket splits the pressure chamber into a first section and a second section. The first section and the second section are in communication with each other by means of the open end of the guiding jacket. The first section is provided with a liquid level, located below the open end, and therefore with a vapour chamber, located above the liquid level.

An evaporator system for an industrial boiler, containing a heat transfer system, a separator for separating water and steam and a dryer for drying the separated wet steam. A horizontal vessel contains a required minimum amount of water, a relatively small steam volume and internals for the separation of water and wet-steam. A vertical vessel contains internals for drying the wet steam to predetermined values by separating liquid from the wet-steam. The horizontal vessel and the vertical vessel are connected to each other by wet-steam piping through which separated wet-steam is transported from the horizontal vessel to the vertical vessel. The vertical vessel has a connection to dry-steam piping for discharging dried steam. The vertical vessel has a connection to a liquid drain piping for transporting liquid from the vertical vessel back to the inlet conduits of the evaporator heat transfer section.