Abstract: A scroll compressor includes a stationary scroll and an orbiting scroll having respective wrap elements in engagement with each other. An inner end portion of an internal wall of one of the wrap elements is partially shaped to represent a curve identical to or approximate to an envelope curve which is obtained through circular translation of a circular arc connected with an external wall of the other wrap element. The radius of the circular arc is so chosen as to increase the shortest distance a.sub.x from each of points on the curve to the external wall of the one wrap element towards the inner end of the one wrap element.

Abstract: A scroll compressor includes an orbital drive mechanism for orbiting an orbiting scroll relative to a stationary scroll. The orbiting scroll is formed with a generally cylindrical boss extending in a direction away from the stationary scroll. The orbital drive mechanism includes a main shaft rotatably supported by a compressor housing, an eccentric shaft extending from one end face of the main shaft and having a longitudinal axis parallel to, but offset laterally from a longitudinal axis of the main shaft, and an eccentric bush having a socket inserted rotatably into the cylindrical boss. The eccentric shaft, engaged in the socket, has first and second rounded side faces opposite to each other both having a common center of curvature, while the socket has first and second inner wall portions opposite to each other, each of which has a center of curvature substantially aligned with the common center of curvature of the first and second rounded side faces of the eccentric shaft.

Abstract: The present invention relates to a method and an apparatus, in which the quality of a large amount of water and/or the quantity of dissolved oxygen in said water is improved and which are characterized in that water, in which slaked lime is dissolved in advance, and/or water of high oxygen content, which is generated in advance, is supplied into water pumped by an intermittent pneumatic water pumping unit so that the water having the slaked lime dissolved therein and/or the water of high oxygen content is diffused in the large amount of water.

Abstract: The present invention relates to a method and apparatus, in which the quality of a large amount of water and/or the quantity of dissolved oxygen in the water is improved. Water in which slaked lime is dissolved in advance and/or water of a high oxygen content which is generated in advance is supplied into water pumped by an intermittent pneumatic water pumping unit so that the water having the slaked lime dissolved therein and/or the water of high oxygen content is diffused in the large amount of water. The present invention also relates to a method and apparatus, in which the quality of a large amount of water and/or the quantity of dissolved oxygen in the large amount of water is improved by water with slaked lime dissolved therein and/or water of high oxygen content being conducted to the bottom of a lake or the like. An intermittent pneumatic water pumping unit is operated in the lake or the like so that the large amount of water is caused to flow up and down and be agitated.

Abstract: A water aeration apparatus is used for aeration purposes in the water-filled areas such as dams, impounded water or reservoirs, and lakes and marshes, and includes a tubular casing and supply chamber that causes large quantities of water to be exposed to the flotation action of air supplied under pressure, thus raising the water up to the surface. The apparatus may be used for water purification, or for anti-freezing purposes particularly in cold climate regions. The apparatus includes a collective tubular casing and a multiple-partitioned or common air supply chamber below the casing, the tubular casing including a plurality of tubular air and water passages formed by dividing the interior of the casing into several longitudinal passages or by combining individual tubes together.

Abstract: A water aeration apparatus is used for aeration purposes in the water-filled areas such as dams, impounded water or reservoirs, and lakes and marshes, and includes a tubular casing and supply chamber that causes large quantities of water to be exposed to the flotation action of air supplies under pressure, thus raising the water up to the surface. The apparatus may be used for water purification, or for anti-freezing purposes particularly in cold climate regions. The apparatus includes a collective tubular casing and a multiple-partitioned or common air supply chamber below the casing, the tubular casing including a plurality of tubular air and water passages formed by dividing the interior of the casing into several longitudinal passages by combining individual tubes together.

Abstract: A method is provided for use with an apparatus which produces jets of water through a vertical water diffuser tube by supplying individually formed air bubble masses at regular intervals, which are followed by the water being drawn under the action of the air bubble masses. The method improves the water processing efficiency and ability of the apparatus by defining the volumetric quantity of a formed air mass in relation to the diameter of the particular air diffuser tube and defining a certain relationship between the length L (m) of the tube through which the rises and the time interval T (sec) at which the individual air bubble masses are produced.

Abstract: A water aeration apparatus is used for aeration purposes in the water-filled areas such as dams, impounded water or reservoirs, and lakes and marshes, and includes a tubular casing and supply chamber that causes large quantities of water to be exposed to the flotation action of air supplied under pressure, thus raising the water up to the surface. The apparatus may be used for water purification, or for anti-freezing purposes particularly in cold climate regions. The apparatus includes a collective tubular casing and a multiple-partitioned or common air supply chamber below the casing, the tubular casing including a plurality of tubular air and water passages formed by dividing the interior of the casing into several longitudinal passages or by combining individual tubes together.