Abstract: A diffuser for the vacuum fan used with agricultural equipment. The diffuser has a rectangular outlet fixed to the outlet of the fan and a diverging rectangular cross-section outlet for increasing the cross-sectional flow area. A primary flow path between the inlet and the outlet is no less in area than the inlet to the diffuser and a series of rectangular side chambers with perforated walls covered by sound deadening material have predetermined dimensions to decrease the outlet air velocity attenuate selected noise frequencies.

Abstract: A diffuser for the vacuum fan used with agricultural equipment. The diffuser has a rectangular outlet fixed to the outlet of the fan and a diverging rectangular cross-section outlet for increasing the cross-sectional flow area. A primary flow path between the inlet and the outlet is no less in area than the inlet to the diffuser and a series of rectangular side chambers with perforated walls covered by sound deadening material have predetermined dimensions to decrease the outlet air velocity attenuate selected noise frequencies.

Abstract: A solar chemical process for converting sewer sludge from a gelatinous mass into a manageable product suitable for fertilizer includes the manufacture of a carbonaceous product by treating cellulose waste such as newspaper with sulfuric acid and heating the mixture until the cellulose product becomes substantially black. The black product is mixed with sludge in a ratio to produce a grainy product that can be chlorinated for sterility and spread as fertilizer. In a modified version of the process, coal ash is added to the sludge with the carbonaceous product for its nutrient value, and sand may be added with the coal ash to aid in aeration of the soil.