Abstract: A cartridge heater is accommodated in a heater bore in a shaft connected to a valve element, and a heating portion provided at an end portion of the cartridge heater is located at a joint portion of the shaft and the valve element. At the joint portion, a heat receiving groove and a pressurizing portion communicating with the heater bore are provided at a position between a surface of the valve element and that of the shaft located so as to oppose and to contact each other. The heat receiving groove includes an arcuate groove portion of the same radius as that of the heating portion of the cartridge heater, and the heating portion is pressed by the pressurizing portion to enter into plane-to-plane contact with an inner circumferential surface of the arcuate groove portion of the heat receiving groove, upon fastening the valve element and the shaft to each other with a bolt, with the heating portion located between the heat receiving groove and the pressurizing portion.

Abstract: Between a driving base operated by an air cylinder and a lever member fixed to a valve shaft integral with a valve plate, a connecting mechanism for connecting the driving base and a lever member, capable of displacement, and a cam mechanism for tilting the lever member are interposed, and a stopper mechanism for stopping the lever member at an opposing position of the valve plate or a full-open position, and after the lever member is stopped by the stopper mechanism at the opposing position or the full-open position, the lever member is tilted by the cam mechanism so as to incline the valve plate and to press a valve seal to a valve seat portion or a wall face in the periphery of an opening.

Abstract: In a gate valve including a valve plate connected to a valve plate mounting portion of at a tip end of a valve rod with a connecting plate and configured to open and close a communicating hole of a valve box with the valve plate, the valve plate includes a mounting hole, a joint flat surfaces coming into press-contact with each other, the valve rod includes a depressed-shaped joint shoulder portion, the joint shoulder portion is formed with an inclined surface configured to guide the valve plate in the direction in which the joint flat surfaces are brought into press-contact with each other, and the coupling plate couples the valve plate and the valve rod with each other.

Abstract: A cartridge heater is accommodated in a heater bore in a shaft connected to a valve element, and a heating portion provided at an end portion of the cartridge heater is located at a joint portion of the shaft and the valve element. At the joint portion, a heat receiving groove and a pressurizing portion communicating with the heater bore are provided at a position between a surface of the valve element and that of the shaft located so as to oppose and to contact each other. The heat receiving groove includes an arcuate groove portion of the same radius as that of the heating portion of the cartridge heater, and the heating portion is pressed by the pressurizing portion to enter into plane-to-plane contact with an inner circumferential surface of the arcuate groove portion of the heat receiving groove, upon fastening the valve element and the shaft to each other with a bolt, with the heating portion located between the heat receiving groove and the pressurizing portion.

Abstract: Between a driving base operated by an air cylinder and a lever member fixed to a valve shaft integral with a valve plate, a connecting mechanism for connecting the driving base and a lever member, capable of displacement, and a cam mechanism for tilting the lever member are interposed, and a stopper mechanism for stopping the lever member at an opposing position of the valve plate or a full-open position, and after the lever member is stopped by the stopper mechanism at the opposing position or the full-open position, the lever member is tilted by the cam mechanism so as to incline the valve plate and to press a valve seal to a valve seat portion or a wall face in the periphery of an opening.

Abstract: A frequency control apparatus for compensating frequency fluctuation in an input received signal from a satellite station of a satellite communication system, comprises a PLL arrangement for generating a frequency converting signal in response to the frequency fluctuation in the input received signal, a mixer for mixing the input received signal and the frequency converting signal to deliver a resultant output signal, and a control circuit for designating a predetermined signal as the frequency converting signal when the PLL arrangement becomes a phase-unlocked state.

Abstract: A filtering method of flue gas of a boiler employing a filter apparatus integrated with ceramic filters and provided with a control mechanism for regenerating the ceramic filter by reverse cleaning and a detecting mechanism for detecting directly or indirectly unburnt component. Valves of a compressed gas are operated by a signal from the control mechanism when flying-over of the unburnt component is detected to thereby start at once frequent reverse cleaning wherein the compressed gas is blown into the cleaned gas spaces and thereafter the frequent reverse cleaning having a period shorter than four minutes continues until the flying-over of the unburnt component decreases to a small quantity.

Abstract: Distribution nozzles are arranged on an air distribution plate disposed at the lower portion of a furnace and spaced apart by a predetermined distance from the bottom thereof and one or more spouted nozzles extend upwardly from the air distribution plate so that not only a fluidized bed defined by the air discharged through the distribution nozzle but also one or more spouted beds defined by the air flows injected through the spouted nozzle or nozzles into the fluidized bed are formed within the furnace. Because of the coexistence of the fluidized bed and the spouted bed or beds, the agitated effect in the fluidized bed is enhanced and the combustion efficiency as well as the desulfurization can be pronounced. A particle feeding pipe is connected to the furnace to feed fuel and desulfurizing agent into the furnace.

Abstract: A fuel supplied through a fuel feed bore of a burner plug and a spray medium supplied through spray medium feed holes thereof are mixed initially in primary mixing chambers in a burner plate and further mixed in a secondary mixing chamber in a burner tip and the fuel mixture thus obtained is sprayed through spray holes of the burner tip. Each of the primary mixing chambers is inclined at a predetermined angle relative to the axis of the burner plate so that the fuel mixture is caused to swirl in a secondary mixing chamber; or the burner plate and the burner tip are so interconnected to each other that the extension of the axis of each primary mixing chamber in the burner plate intersects substantially the midpoint between the adjacent spray holes of the burner tip and consequently the fuel mixture discharged from the primary mixing chambers impinges on the inner wall of the secondary mixing chamber in the burner tip, whereby the ability to atomize a slurry fuel is improved.

Abstract: Temperature of exhaust gases from a fluidized-bed boiler is lowered by means of heat exchange and dust entrained in the exhaust gases is efficiently collected by a dust collector. Part of the gases discharged from the dust collector are mixed with heated combustion air and are charged into a fluidized bed. Therefore, problems caused by dust entrained in the exhaust gases to be mixed with the combustion air as well as the cold corrosion problem can be substantially solved so that the technique for reducing the NO.sub.x contents in the exhaust gases from the fluidized-bed boiler is satisfactorily established.

Abstract: A device for protecting wear of heat transfer tubes in a fluidized-bed boiler is disclosed. The protective device is applied to a portion of a heat transfer tube which is strongly and exceedingly attacked by fluidized bed materials, so that the considerable decrease in service life of a heat transfer tube due to wear caused by the attack of fluidized bed materials can be avoided.