Hitachi, Ltd.

Nisshin Steel Co., Ltd.

Heihatiro Midorikawa

Masahiko Itoh

Michihiko Aizawa

Katsumi Mabuchi

Akira Minato

Takashi Honda

Tomoko Kikuchi

Masahiko Ito

Yasumasa Furutani

Kenzi Machizawa

Masakiyo Izumiya

Takehiko Ito

Teruo Yamaguchi

Kiichiro Katayama

Kazutoshi Itoh

Kenji Machizawa

Mituru Kubo

An absorption refrigerator includes a high temperature regenerator for heating a water solution including a halogen compound to generate steam. An oxide film having thickness of 0.02&#x2013;5.0 &#x3bc;m, one of the colors blue, purple and gray, or a hydroxyl group is formed on a surface of at least one of the high temperature regenerators and the heat exchanger.

Absorption refrigerator and production method thereof

An absorption refrigerator includes a high temperature regenerator for heating a water solution including a halogen compound to generate steam. An oxide film having thickness of 0.02-5.0 &mgr;m, one of the colors blue, purple and gray, or a hydroxyl group is formed on a surface of at least one of the high temperature regenerators and the heat exchanger.

An absorption refrigerator uses water as a refrigerant and a halogen compound as an absorption solution, and is characterized in that an oxide film of thickness of 0.02-5.0 .mu.m is formed on a surface of at least one of a heat exchanger and a high temperature regenerator. And a production method of the absorption refrigerator is characterized by oxidizing a surface of at least one of a heat exchanger and a high temperature regenerator at a temperature of 200-800.degree. C., and adjusting a heating temperature and a heating retaining time so that a value of parameter (P), obtained according to P=T (5+log t) is 3.5-6.0.times.10.sup.3, wherein T represents heating temperature (.degree.K), and t heating retaining time (minute).

An absorption refrigerator uses water as a refrigerant and a halogen compound as an absorption solution, and is characterized in that an oxide film of thickness of 0.02-5.0 .mu.m is formed on a surface of at least one of a heat exchanger and a high temperature regenerator. And a production method of the absorption refrigerator is characterized by oxidizing a surface of at least one of a heat exchanger and a high temperature regenerator at a temperature of 200.degree.-800.degree. C., and adjusting a heating temperature and a heating retaining time so that a value of parameter(P), obtained according to P=T (5+log t) is 3.5-6.0.times.10.sup.3, wherein T represents heating temperature (.degree.K), and t heating retaining time (minute).

A method of descaling stainless steel which provides a smooth and glossy surface, comprises the steps of (a) anode-electrolyzing stainless steel having scales thereon in an aqueous neutral salt solution, (b) anode-electrolyzing or immersing the stainless steel in an aqueous alkaline solution. Steps (a) and (b) are performed in the order of either (a), (b), (a). The method further comprises the step of cathode-electrolyzing the stainless steel treated in the previous two steps in an aqueous nitric acid solution or immersing it in an aqueous solution of a mixture containing nitric acid and fluoric acid.

Method and apparatus for descaling stainless steel

A hermetically closed circulation type, vapor absorption refrigerator which comprises a high temperature regenerator, a low temperature regenerator a condenser, an evaporator, an absorber and heat exchangers in a hermetically closed circulation system as essential constituent members composed of iron-based materials, where refrigeration is produced by repetitions of concentration of an absorbing solution sealed into the circulation system, dilution with a cooling medium and heat exchange, the inside wall of the high temperature regenerator being provided with a composite film of molybdenum oxides and iron oxide can be operated stably with a high reliability or corrosion resistance.

Hermetically closed circulation type, vapor absorption refrigerator

An absorption type refrigerator has an aqueous absorbing solution. The absorbing solution comprises lithium bromide solution, 5-150 ppm by weight of NO.sub.3.sup.- and 0.1-0.4% by weight of LiOH, and is free from any triazole compounds. The absorbing solution further includes octyl alcohol.

Absorption type refrigerator and absorbing solution therefor

A process for the partial hot dipping of a long steel strip is disclosed which comprises forming an oxidation-inhibiting film, oxygen-impermeable and thermally stable in a hot-dipping bath, which film is produced by the chemical reaction of an iron content in the steel strip with an oxidation inhibiting film-forming agent, such as an inorganic phosphoric acid compound, on a predetermined area of the steel strip surface, forming, as required, an intermediate layer comprising an inorganic binder, such as water glass, on the resulting film, forming a carbon-containing, plateing-stopping film as a top coat on the intermediate layer, and hot dipping the steel strip.

Process for partial hot dipping of steel strips

In a hermetically circulating absorption type refrigerator including a regenerator, a condenser, an evaporator, an absorber and a heat exchanger, the regenerator has an absorbing solution heating tube flux provided between tube plates. The tube plates are encased within a shell of the regenerator. Non-soluble electrodes are arranged between each of the tube plates and the shell. Then, an anti-corrosive current is made to flow through at least one of an end portion of the heating tube, the tube plates and the shell to thereby enhance the anti-corrosion effect together with an anti-corrosive agent or inhibitor.

Hermetically circulating, absorption type refrigerator

In a hermetically circulating, absorption type refrigerator based on a closed circulation system of constituent members comprised of a successive communication of a regenerator, a condenser, an evaporator, an absorber and a heat exchanger, refrigeration being produced by repetitions of concentration, refrigerant dilution, and heat exchange of an aqueous concentrated lithium bromide solution sealed in the circulation system, the aqueous concentrated lithium bromide solution contains at least one each of (a) an inhibitor having a boiling point higher than the solution temperature in the regenerator and (b) an inhibitor having a boiling point lower than the solution temperature in the regenerator. Corrosion of metallic materials used in a refrigerant circulation loop of the refrigerator and those in the absorbing solution circulation loop can be effectively prevented.

In a hermetically circulating, absorption type refrigerator based on a closed circulation system of constituent members comprised of a successive communication of a regenerator, a condenser, an evaporator, an absorber and a heat exchanger, refrigeration being produced by repetitions of concentration, refrigerant dilution, and heat exchange of an aqueous concentrated lithium bromide solution sealed in the circulation system, a hydrogen gas generated in the refrigerator is continuously converted to water, condensed and removed or returned to the refrigerator as a refrigerant. The pressure increase in the refrigerator can be prevented, and a high refrigerating performance can be continuously maintained without any special maintenance.

A hermetically circulating, absorption type refrigerator based on a closed circulation system comprised of a successive communication of a regenerator, a condenser, an evaporator, an absorber and a heat exchanger, parts or the whole of said constituent members in contact with an absorbing solution being comprised of a copper material selected from copper and copper alloy, and refrigeration being produced by repetitions of concentration, refrigerant dilution and heat exchange of an aqueous lithium bromide solution sealed in the circulation system is characterized in that the absorbing solution is an aqueous lithium bromide solution containing (a) a nitrate and (b) at least one triazole compound selected from benzotriazole and tolyltriazole, and has a particularly distinguished corrosion resistance.

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Ibaraki, Japan

Heihatiro Midorikawa