Al oxide dispersed Ni-Cu porous sintered alloy was fabricated by a tape casting process followed by a sintering process consisting of oxidation and reduction from Ni-45%Cu-5%Al atmized alloy powder. Conditions of the tape casting process and the relationship between sintering temperature and porosity of the sintered alloys were investigated.
Metal powder could be tape-casted in the viscosity range of the slurry during 10, 000-20, 000 cps. Thickness of the green compacts was proportional to blade height. Densities of the green compacts were similar to the tap densities of raw powders. After sintering, porosity of the sintered alloy changed little from the green compacts. These results indicated that the porosity (or density) of the sintered alloy made by this fabrication process could be predicted from the tap density data of raw powder materials.

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The most common problems of discharge electrodes in electrostatic precipitators are associated with failures of mechanical, electrical and chemical factors. We carried out tests utilizing an electro-charged water column for discharge electrodes instead of the wires. This system is applied to both a wet and dry process. In the former process, the electro-charged water column and electro-charged droplets are generated by the application of a high voltage directly to water. Dust particles are collected by electrostatic force and scrubbing. In the latter process, an electro-charged water column is produced to use a straight nozzle and is charged negatively with a 10-30kV power supply. Calcium carbonate is used for the test powder.
The main results are summarized as follows: (1) Although this system is looked forward to as being a new precipitator type having two features, both electrostatic precipitators and scrubbers in a wet process, it is similiar to the collection mechanism in comparison with the conventional wet type of electrostatic precipitators; (2) In a dry process, the electrical characteristics of an electro-charged water column have advantages over that of wires. This system is achieved to attain the maximum electric power and the maximum field strength without rapping.
However it is necessary to establish a method of making a water column, about 5m in length. The electro-charged water column in a dry process has been proven advantageous for specific applications.

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