Development and Practical Application of Very-Large-Luminous-Flux 50kW High-Pressure Sodium Vapor Lamp System

Photoreaction tank(image diagram)

Fig.1 Photoreaction tank(image diagram)

60kW Metal-halide lamp

Photo.1 60kW Metal-halide lamp

50kW High-pressure sodium vapor lamp

Photo.2 50kW High-pressure sodium vapor lamp

Rating of 50kW High-pressure sodium vapor lamp

Tbl.1 Rating of 50kW High-pressure sodium vapor lamp

  As an example of large-scale practical industrial use of photochemical reaction, there is the photosynthetic method for the caprolactam, which is an in-process material for nylon, developed by Toray Industries, Inc. (Fig. 1). This photochemical reaction (PNC method) requires larger number of photons (light quanta) in visible light range. To meet this requirement, 10 to 20kW high-power high-pressure mercury lamps were developed around 1961 to 1963. And around 1964 to 1971, 10 to 60kW high-power metal halide lamps (Photo 1) were developed and applied practically.

  The 50kW high-pressure sodium vapor lamps applied practically in 1988 (Photo 2) had been developed aiming for higher efficiency and longer life. This lamp realized 27% higher efficiency and 20% higher power-saving effect than those of metal halide lamp. The luminous flux reached 8 million lumens (Table 1), and the total brightness of ten lamps is nearly equal to the luminous flux of large-scale night lighting for baseball stadium.

  The high-pressure sodium vapor lamps have been widely used as the lamps for general lighting, but their lamp powers were 1kW or less. The higher power and higher efficiency were achieved by arc tube’s optimal design and the developments of large-diameter long-length alumina tube with high translucency and many other new technologies such as electrode sealing technology suitable for large current, special evacuation technology and lamp lighting system.

  This high-pressure sodium vapor lamp leads to the applications to many photochemical reactions and general lightings, as well as the application of large-diameter long-length alumina tube as a high-heat resistant and high-purity material.

  The Illuminating Engineering Institute of Japan (IEIJ) presented the following award for this development.

1. Award Name: IEIJ Japan Lighting Award “Development and Practical Application of the World’s-Largest-Luminous-Flux 50kW High-Pressure Sodium Vapor Lamp System”

2. Award Winner: Akihiro KAMIYA, Akihiro YONEZAWA, Yasuki MORI, Teruo OSHIMA (Toshiba Lighting & Technology Corp.); Katsuhiko SUZUKI, Tetsuya YOSHIKAWA (Toray Industries, Inc.); and Shunzo SHIMAI, Noboru IGARASHI (Toshiba Ceramics Co., Ltd.)

3. Awarded Year: 1990


[1] Super High Power High-Pressure Sodium Lamp、1990、IES Session

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