Abstract: An electrically driven construction machine is provided in which, in a case where a plurality of electrically driven construction machines operate simultaneously, it is possible to avoid exceeding the allowable electric power that can be output by the electric power receiving facility of a commercial electric power supply. A controller computes an own demanded power Pd1 for driving the plurality of hydraulic actuators, on the basis of operation signals of the operation devices, computes an allowable power as a power limit value usable by the electric motor on the basis of the own demanded power, the demanded powers of the other electrically driven construction machines received through the communication device, and an allowable electric power of the electric power receiving facility of the commercial electric power supply, and controls the electric motor such that a power consumption of the electric motor does not exceed the allowable power.

Abstract: A vinyl chloride polymer is prepared by charging a reactor with a vinyl chloride monomer, effecting polymerization, removing a slurry of the polymer from the reactor, and washing the reactor interior with water, and repeating the series of steps. The reactor has an internal volume of at least 40 m3. A cylinder-guided lift type washer assembly having a nozzle is secured to the reactor at its top in a sealed manner such that the nozzle can be moved downward and upward in the reactor. Water is fed to the nozzle through the assembly for injecting water from the nozzle into the reactor for cleaning. The large size reactor can be effectively washed with water in the closed state, and vinyl chloride polymers of quality with least fisheyes are produced batchwise, leading to an improved productivity.

Abstract: Disclosed are a catalyst filter characterized in that catalyst particles which are made of titanium oxide and vanadium oxide or titanium oxide, vanadium oxide and tungsten oxide and whose diameters are between 0.01 and 1 .mu.m are carried by a filter made by weaving monofilaments of a glass fiber and/or of a catalytic fiber;a method for manufacturing thereof; anda comprehensive method for treating a combustion exhaust gas characterized in that an alkaline powder or ammonia or its precursor is supplied to a flow of a combustion exhaust gas containing toxic substances such as dust, acidic gases and nitrogen oxides, and the flow of a combustion exhaust gas is let pass through a filter carrying a catalyst for denitrating the above combustion exhaust gas.

Abstract: An electronic blackboard includes a writing sheet movable along a predetermined path and having a plurality of writing sections spaced apart one from another, reading means for optically reading the writing sheet, and recording means for recording information read by the reading means of a recording medium as a hard copy. In one aspect, the image information read by the reading means is subjected to thresholding operation to produce a binary image data, and a standard concentration pattern is provided on the recording sheet and it is used to automatically set a proper threshold level to be used in the thresholding operation. In another aspect, it is so structured that the writing sheet may be stopped with one of the plurality of writing sections in registry with or out of registry with a predetermined window.