Abstract: A memory card 110 extracts a session key Ks from the data applied onto a data bus BS3 by carrying out a decryption process. An encryption processing unit 1406 encrypts a public encryption key KPcard(1) of memory card 110 based on session key Ks, and applies the encrypted key to a server via data bus BS3. A memory 1412 receives from a server data such as license key Kc, license ID data License-ID and user ID data User-ID encrypted with a public encryption key KPcard(1) differing for each memory card for storage, and receives encrypted content data [Dc]Kc encrypted with license key Kc from data bus BS3 for storage.

Abstract: A heating apparatus 1 includes a shell 2, a primary heat exchanger (sensible heat exchanger) 3, a burner (combustion means) 5, and a fan 6. A secondary heat exchanger (latent heat exchanger) 7 has a plurality of heat receiving tubes 18 arranged in parallel between a pair of headers 16 and 17, the heat receiving tubes 18 being fixed to tube plates 20. The heat receiving tubes 18 are bare tubes without fins and are arranged across flow of combustion gas. The number of the tubes 18 arranged vertically is less than the number of the tubes 18 arranged horizontally.

Abstract: A heating apparatus 1 includes a shell 2, a primary heat exchanger (sensible heat exchanger)3, a burner (combustion means) 5, and a fan 6. A secondary heat exchanger (latent heat exchanger) 7 has a plurality of heat receiving tubes 18 arranged in parallel between a pair of headers 16 and 17, the heat receiving tubes 18 being fixed to tube plates 20. The heat receiving tubes 18 are bare tubes without fins and are arranged across flow of combustion gas. The number of the tubes 18 arranged vertically is less than the number of the tubes 18 arranged horizontally.

Abstract: A combustion apparatus 2 has a fuel spraying nozzle 12, a feed canal 16 and a return canal 17, both the canals connected to the nozzle, with the former canal 16 feeding a fuel to the nozzle and with the later canal 17 allowing an unsprayed portion of the fuel to flow back. An electro-magnetic pump 18 disposed in the feed canal 16 serves to compress the fuel towards the nozzle 12, and an injector valve 25 is disposed in the return canal 17. A low rate at which the fuel is sprayed out from the nozzle is controlled by a controlling means 40 by regulating the mode of opening and closing the valve body 33 of injector valve 25.

Abstract: A combustion apparatus 2 has a fuel spraying nozzle 12, a feed canal 16 and a return canal 17, both the canals connected to the nozzle, with the former canal 16 feeding a fuel to the nozzle and with the latter canal 17 allowing an unsprayed portion of the fuel to flow back. An electromagnetic pump 18 disposed in the feed canal 16 serves to compress the fuel towards the nozzle 12, and an injector valve 25 is disposed in the return canal 17. A controller 40 regulates the operation of the injector valve 25 in the manner of duty-ratio control so as to adjust the flow rate of the fuel being sprayed out of the nozzle 12.

Abstract: A combustion apparatus 2 has a fuel spraying nozzle 12, a feed canal 16 and a return canal 17, both the canals connected to the nozzle, with the former canal 16 feeding a fuel to the nozzle and with the later canal 17 allowing an unsprayed portion of the fuel to flow back. An electromagnetic pump 18 disposed in the feed canal 16 serves to compress the fuel towards the nozzle 12, and an injector valve 25 is disposed in the return canal 17. A low rate at which the fuel is sprayed out from the nozzle is controlled by a controlling means 40 by regulating the mode of opening and closing the valve body 33 of injector valve 25.

Abstract: A combustion apparatus 2 has a fuel spraying nozzle 12, a feed canal 16 and a return canal 17, both the canals connected to the nozzle, with the former canal 16 feeding a fuel to the nozzle and with the latter canal 17 allowing an un-sprayed portion of the fuel to flow back. An electro-magnetic pump 18 disposed in the feed canal 16 serves to compress the fuel towards the nozzle 12, and an injector valve 25 is disposed in the return canal 17. The injector valve 25 is accommodated in a casing 50 consisting essentially of an inlet joint 46 and an outlet joint 17.

Abstract: A combustion apparatus 2 has a fuel spraying nozzle 12, a feed canal 16 and a return canal 17, both the canals connected to the nozzle, with the former canal 16 feeding a fuel to the nozzle and with the latter canal 17 allowing an unsprayed portion of the fuel to flow back. An electromagnetic pump 18 disposed in the feed canal 16 serves to compress the fuel towards the nozzle 12, and an injector valve 25 is disposed in the return canal 17. A controller 40 regulates the operation of the injector valve 25 in the manner of duty-ratio control so as to adjust the flow rate of the fuel being sprayed out of the nozzle 12.