Abstract: A method for controlling the temperature of water to be fed into a water cooling tower in which when the driving power required to drive motors to be controlled is in excess of the power which can be derived from a frequency converter, some of the motors are driven by a constant-frequency power supply while the remaining motors are driven by the frequency converter. Therefore, the temperature of water to be fed into the water cooling tower can be continuously controlled without increasing the capacity of the frequency converter.

Abstract: Process and apparatus for calcining finely divided cement raw materials including finely divided combustible materials in a suspension preheater with a calcining furnace. Finely divided calcareous materials are directly charged into the suspension preheater while finely divided argillaceous materials, including combustibles such as oil shale, are charged into a bypass duct for bypassing part of the high temperature gases in the suspension preheater to a calcining zone or calcining furnace. The raw materials charged into the bypass duct are subjected to thermal decomposition, resulting in solids and combustible gases. The combustible gases are separated from the solids and are charged into the calcining zone or calcining furnace while the separated solids are charged into the suspension preheater, mixed with the finely divided calcareous materials, preheated and calcined.

Abstract: Almost all of the powder materials, after having been calcined in a calcining furnace, are treated by the high temperature kiln exhaust without being directly fed into a rotary kiln, so that the materials may pass through at least two calcining zones in series so that they are calcined perfectly and uniformly before they are fed into the kiln, thereby contributing to make compact a rotary kiln in size and to improve overall thermal efficiency of the calcining and burning (sintering) apparatus.

Abstract: A particle charging device for use in a two-stage type of electric dust collecting apparatus, including opposite electrodes disposed at such positions that an intermittent ion generating zone is established between the opposite electrodes and ion generating electrodes, and that uneven, non-uniform electric fields are established between said opposite electrodes and transfer electrodes; a dust containing gas is ionized in the intermittent ion generating zone, and upon transferring the ions by means of the uneven electric field, said ions are brought in contact with a flow of particles in said dust containing gas to thereby charge said particles.

Abstract: An improved dust collecting apparatus is described, in a first section of which are disposed a plurality of linear discharge electrodes and a plurality of planar dust collecting electrodes in an opposed relationship to each other within a casing that has an inlet port for introducing a dust-containing gas formed at one end and that has an outlet port for discharging a dust-free gas formed at the other end, so that the dust in the dust-containing gas may be charged and also collected in said first section. Downstream of said first section of the apparatus are aligned a plurality of rod-shaped driver electrodes spaced apart from each other along a plane transverse of a gas flow, and on the side surfaces of said driver electrodes are provided lengthwise channels having their openings directed to the outlet port side.