Abstract: A service managing apparatus for managing a state of a service controlling apparatus providing services in response to a request from an exchange has a request number reading unit for reading the number of requests for service supply from the exchange held by the service controlling apparatus, a database reading unit for reading contents of a database for service operation possessed by the service controlling apparatus, a collating unit for collating the read contents with contents in a corresponding region of a subscriber database, and a read control unit for controlling the reading of the contents of the database on the basis of the request number information read out by the request number reading unit, thereby periodically detecting normality of the databases in a network in service operation to prevent degradation of the services even if the number of transactions is increased.

Abstract: Only suspension type superheaters (52) and (53) are disposed in an outlet of a furnace. These superheaters have heat transfer areas which are so dimensioned that an exhaust gas temperature at downstream of the superheaters is 1000.degree. C. to 1100.degree. C. when the boiler is under a maximum load. An exhaust gas passage downstream of the superheaters (52) and (53) is divided into sub passages along a flow of an exhaust gas, and a damper is disposed in an outlet of each of the sub passages for adjusting a flow rate of the exhaust gas flowing through the respective sub passages. A traverse type reheater (41) is disposed in the sub passage. Since a difference between a temperature (1000.degree. C. to 1100.degree. C.) of the exhaust gas flowing around the reheater (41) and a temperature of steam flowing through the reheater (41) is large, heat exchange can be performed with a high efficiency even through a small heat transfer area.

Abstract: A finned tube comprises a tube; and a fin strip having fins formed by forming slits of a predetermined length in a fin portion of a strip and at predetermined intervals, and a base portion in which no slit is formed, and wound around the tube so that the fins thereof extend substantially radially of the tube. The fins are twisted at a twist angle in the range of 2.degree. to 40.degree. to a contact line along which the base portion of the fin strip is in contact with the tube, and inclined at an inclination angle in the range of 2.degree. to 20.degree. to a straight line perpendicular to the axis of the tube. A heat exchanger is provided with a plurality of such finned tubes, and a heat recovery apparatus comprises such a heat exchanger disposed in a combustion gas passage.