Abstract: An insert tube is used for the repair or improvement of a pre-heating tube for air arranged in an exhaust gas pathway of a fuel burner. A pre-determined radial gap exists between the outer surface of the insert tube and the inner surface of the pre-heating tube for air such that the insert tube can be slid into the pre-heating tube for air. The insert tube is provided in the vicinity of each end with at least one groove that runs around its circumference. In the groove there is arranged at least one sealing ring of an elastic material. The sealing ring mounted in the groove has an external diameter that exceeds the internal diameter of the preheating tube for air. The sealing ring forms a seal against the inner surface of the pre-heating tube for air and prevents leakage through the sealing ring.

Abstract: A tube shield has a cylindrical shape and adapted to be attached with refractory cement (R) around an outer peripheral surface of a boiler tube (T). The tube shield has at least two tube shield parts for surrounding the boiler tube (T). The shield parts has complimentary parting surfaces for defining a gap between abutting complimentary parting surfaces of adjacent shield parts when the shield parts are attached with refractory cement (R) around the boiler tube (T). Each shield part encloses 140-220° of the total circumference of the boiler tube (T). Each complimentary parting surface is configured in a dovetail form such that one shield part is locking into the other shield part with dovetail protrusions (DP) located in dovetail slots (DS) in the other shield part.

Abstract: The steam boiler has a circulation system for boiler water that has water pipes arranged to circulate boiler water and steam through the water pipes with a cooled device arranged to cool a selected, exposed part of the steam boiler. The cooled device has an outer tube and an inner tube arranged in the outer tube. The outer tube, at an upper end thereof, has an open connection to one of the water pipes in which water pipe a flow is established.

Abstract: An insert tube is used for the repair or improvement of a pre-heating tube for air arranged in an exhaust gas pathway of a fuel burner. A pre-determined radial gap exists between the outer surface of the insert tube and the inner surface of the pre-heating tube for air such that the insert tube can be slid into the pre-heating tube for air. The insert tube is provided in the vicinity of each end with at least one groove that runs around its circumference. In the groove there is arranged at least one sealing ring of an elastic material. The sealing ring mounted in the groove has an external diameter that exceeds the internal diameter of the preheating tube for air. The sealing ring forms a seal against the inner surface of the pre-heating tube for air and prevents leakage through the sealing ring.

Abstract: A tube shield has a cylindrical shape and adapted to be attached with refractory cement (R) around an outer peripheral surface of a boiler tube (T). The tube shield has at least two tube shield parts for surrounding the boiler tube (T). The shield parts has complimentary parting surfaces for defining a gap between abutting complimentary parting surfaces of adjacent shield parts when the shield parts are attached with refractory cement (R) around the boiler tube (T). Each shield part encloses 140-220° of the total circumference of the boiler tube (T). Each complimentary parting surface is configured in a dovetail form such that one shield part is locking into the other shield part with dovetail protrusions (DP) located in dovetail slots (DS) in the other shield part.

Abstract: An air nozzle has an attachment arrangement for solid fuel burners with fluidized beds. The air nozzle has a body having an inlet and an outlet defined therein. A pipe end is inserted into the inlet. The attachment arrangement secures the pipe end inside the body. The attachment arrangement has a first part engaging a through hole of the body and a second perpendicular part that engages a cavity of the pipe end.

Abstract: An insert tube is used for the repair or improvement of a pre-heating tube for air arranged in an exhaust gas pathway of a fuel burner. A pre-determined radial gap exists between the outer surface of the insert tube and the inner surface of the pre-heating tube for air such that the insert tube can be slid into the pre-heating tube for air. The insert tube is provided in the vicinity of each end with at least one groove that runs around its circumference. In the groove there is arranged at least one sealing ring of an elastic material. The sealing ring mounted in the groove has an external diameter that exceeds the internal diameter of the preheating tube for air. The sealing ring forms a seal against the inner surface of the pre-heating tube for air and prevents leakage through the sealing ring.

Abstract: An air nozzle has an attachment arrangement for solid fuel burners with fluidized beds. The air nozzle has a body having an inlet and an outlet defined therein. A pipe end is inserted into the inlet. The attachment arrangement secures the pipe end inside the body. The attachment arrangement has a first part engaging a through hole of the body and a second perpendicular part that engages a cavity of the pipe end.