Abstract: An air diffuser includes: a bottom panel provided in a horizontal direction in a tank in which water is filled; an air diffusion body installed to cover the bottom panel from above; and air diffusion holes arranged to penetrate through the air diffusion body, gas fed to a gap between the bottom panel and the air diffusion body is discharged into water through the air diffusion holes, and an air diffusion region of the air diffusion body where the air diffusion holes are arranged has a width equal to or larger than 10 mm and smaller than 120 mm.

Abstract: A technique is provided that can further reduce power at the time of “unload operation control” in a gas compressor that generates a compressed gas at a set pressure by constant-speed control. The gas compressor includes a compressor main unit, a drive source, an intake throttle valve, a gas release valve, rotation speed converting means, a pressure detecting device that detects a discharge pressure, and a controller that, the relationship between an upper-limit pressure H and a lower-limit pressure L being H>L, carries out opening the intake throttle valve and closing the gas release valve and operating the drive source at a full-load rotation speed until the discharge pressure reaches the upper-limit pressure H. The controller carries out at least one of closing the intake throttle valve and opening the gas release valve to reduce the discharge pressure to within a predetermined range when the discharge pressure reaches the upper-limit pressure H.

Abstract: In an oil-cooled screw compressor, a tooth crest arc of a fixed width is provided to the tooth crest of a male tooth profile, and simultaneously a tooth bottom arc is provided to the tooth bottom of a female tooth profile. Due to the actions thereof, the operation chamber immediately before disappearing exists only in a bottom half region from a line that connects the centers of the male and female tooth profiles, and the opening area relative to the volume of the operation chamber can be increased. As a result, the discharge of oil becomes smooth and energy loss is reduced.

Abstract: A technique is provided that can further reduce power at the time of “unload operation control” in a gas compressor that generates a compressed gas at a set pressure by constant-speed control. The gas compressor includes a compressor main unit, a drive source, an intake throttle valve, a gas release valve, rotation speed converting means, a pressure detecting device that detects a discharge pressure, and a controller that, the relationship between an upper-limit pressure H and a lower-limit pressure L being H>L, carries out opening the intake throttle valve and closing the gas release valve and operating the drive source at a full-load rotation speed until the discharge pressure reaches the upper-limit pressure H. The controller carries out at least one of closing the intake throttle valve and opening the gas release valve to reduce the discharge pressure to within a predetermined range when the discharge pressure reaches the upper-limit pressure H.

Abstract: A network simulation device of the present invention: accepts an input of first plane information being positional information on a network projected onto a coordinate plane having any two dimensions out of three dimensions as coordinate axes; creates network model information which defines a coordinate value of the remaining one dimension as unknown based on the accepted first plane information; accepts selection of the element having the coordinate value defined as unknown by a user from the elements which appear in the first plane information; accepts an input of second plane information being positional information on the network projected onto a coordinate plane having any two dimensions including the remaining one dimension as coordinate axes; and determines a numerical value of the coordinate value defined as unknown of the selected element in the created network model information based on the accepted second plane information.

Abstract: A chemical feed control device controls feeding of a chemical into a water system of a plant. A water quality index-obtaining unit obtains a water quality index value for each of a plurality of disruptive factors of the water system. An environmental data-obtaining unit obtains environmental data related to the plant. An operational data-obtaining unit obtains operational data related to the plant. A determination unit determines a feed amount of each of a plurality of chemicals acting on at least one disruptive factor and having components different from each other with respect to the water system based on the water quality index value, the environmental data, and the operational data such that the water quality index value for each of the disruptive factors approximates a water quality target value for each of the disruptive factors.

Abstract: Size reduction of a compressor and cooling of an electric motor are effectively achieved. An oilless compressor, having: a compressor main body that has a rotor for compressing air, a rotor shaft for supporting the rotor, and a bearing for rotatably supporting the rotor shaft; an electric motor for producing drive force for driving the compressor main body; at least one gear for transmitting drive force to the rotor shaft; a lubricating oil pipe for conveying lubricating oil to the bearing and/or the gear; and an oil pump for pressure-feeding the lubricating oil; wherein the electric motor has, in the external peripheral direction of an armature, a cooling jacket for channeling the lubricating oil to an internal flow channel to cool the armature of the electric motor, and the lubricating oil circulates through the cooling jacket and the lubricating oil pipe.

Abstract: The objective of the present invention is to reduce loss factors that occur inside an oil-cooled screw compressor and to improve energy efficiency. In oil-cooled screw compressors, compression is carried out by reducing the volume of an operation chamber in which a gas to be compressed and an oil are mixed and contained, and when a predetermined rise in pressure is complete, a discharge port opens and the gas to be compressed and the oil are discharged. In the operation chamber, the reduction in volume continues and reaches zero, such that the operation chamber disappears, and the opening area of the discharge port also gradually decreases. Immediately before the operation chamber disappears, the ratio of the oil within the operation chamber is high and the opening area of the discharge port is small. Therefore, the discharge resistance increases and the internal pressure dramatically rises, and this has led to increases in the torque rotating the rotor.

Abstract: Size reduction of a compressor and cooling of an electric motor are effectively achieved. An oilless compressor, having: a compressor main body that has a rotor for compressing air, a rotor shaft for supporting the rotor, and a bearing for rotatably supporting the rotor shaft; an electric motor for producing drive force for driving the compressor main body; at least one gear for transmitting drive force to the rotor shaft; a lubricating oil pipe for conveying lubricating oil to the bearing and/or the gear; and an oil pump for pressure-feeding the lubricating oil; wherein the electric motor has, in the external peripheral direction of an armature, a cooling jacket for channeling the lubricating oil to an internal flow channel to cool the armature of the electric motor, and the lubricating oil circulates through the cooling jacket and the lubricating oil pipe.

Abstract: An oil-cooled gas compressor provided with a compressor body, an oil separator that separates out oil from a compressed gas, a gas pipe for sending the compressed gas, from which oil has been separated out by the oil separator, to a user, and an oil pipe for returning, to the compressor, the oil separated out by the oil separator. An air-cooled heat exchanger for cooling the aforementioned oil, a controllable-speed cooling fan for blowing cooling air at said air-cooled heat exchanger, and a waste-heat-recovery heat exchanger, provided upstream of the air-cooled heat exchanger, for recovering heat from the oil flowing through the abovementioned oil pipe, are also provided. The speed of the cooling fan is controlled so as to bring the temperature of the compressed gas discharged from the compressor body to within a prescribed range.

Abstract: A network simulation device of the present invention: accepts an input of first plane information being positional information on a network projected onto a coordinate plane having any two dimensions out of three dimensions as coordinate axes; creates network model information which defines a coordinate value of the remaining one dimension as unknown based on the accepted first plane information; accepts selection of the element having the coordinate value defined as unknown by a user from the elements which appear in the first plane information; accepts an input of second plane information being positional information on the network projected onto a coordinate plane having any two dimensions including the remaining one dimension as coordinate axes; and determines a numerical value of the coordinate value defined as unknown of the selected element in the created network model information based on the accepted second plane information.

Abstract: In a water-supply line for performing water-supply to the rotors and the mechanical seal of a compressor, or in a condensed-water collection line for collecting condensed water of a dryer into the inlet port of the compressor, a water reservoir is provided at a position higher than the water-supply unit of the compressor. Moreover, there are provided a start-time water-supply line and a solenoid valve set up therein. Here, the start-time water-supply line establishes the connection between the lower portion of the water reservoir, and the inlet port of the compressor and the water-supply unit of the mechanical seal.

Abstract: An oil-cooled gas compressor provided with a compressor body, an oil separator that separates out oil from a compressed gas, a gas pipe for sending the compressed gas, from which oil has been separated out by the oil separator, to a user, and an oil pipe for returning, to the compressor, the oil separated out by the oil separator. An air-cooled heat exchanger for cooling the aforementioned oil, a controllable-speed cooling fan for blowing cooling air at said air-cooled heat exchanger, and a waste-heat-recovery heat exchanger, provided upstream of the air-cooled heat exchanger, for recovering heat from the oil flowing through the abovementioned oil pipe, are also provided. The speed of the cooling fan is controlled so as to bring the temperature of the compressed gas discharged from the compressor body to within a prescribed range.

Abstract: An air compressor includes a compressor body, an electric motor, a gear mechanism, a gear casing, a partitioning wall, and a screw seal. The screw seal locates in a through hole formed to the partitioning wall, where a rotating shaft of the electric motor passes through, and makes an air flow from the electric motor side to the gear mechanism side in the through hole with rotating of the rotation shaft. The air compressor also includes a bearing that supports that rotating shaft is arranged to the gear mechanism side of the partitioning wall, such that a rotor of the electric motor has overhang structure. The air compressor also includes a communication hole that communicates the electric motor side from the screw seal of the through hole and an outside of the air compressor not through the internal space of the casing of the electric motor.

Abstract: An oil-cooled gas compressor provided with: a compressor body (3); an oil separator (6) that separates out oil from a compressed gas; a gas pipe (8) for sending the compressed gas, from which oil has been separated out by the oil separator, to a user; and an oil pipe (7) for returning, to the compressor, the oil separated out by the oil separator. The following are also provided: an air-cooled heat exchanger (13) for cooling the aforementioned oil; a controllable-speed cooling fan (14) for blowing cooling air at said air-cooled heat exchanger; and a waste-heat-recovery heat exchanger (10), provided upstream of the air-cooled heat exchanger, for recovering heat from the oil flowing through the abovementioned oil pipe. The speed of the cooling fan is controlled so as to bring the temperature of the compressed gas discharged from the compressor body to within a prescribed range.

Abstract: Disclosed is a motor control apparatus for controlling a synchronous motor, which includes a receiver section for receiving the value detected by a temperature sensor installed inside the synchronous motor. The synchronous motor is started up with the current fed into it, whose magnitude is changed in accordance with the temperature received by the receiver section at the time of starting up the synchronous motor. In this way, the stable startup of the synchronous motor can be guaranteed and the useful life of the semiconductor elements can also be prolonged.

Abstract: An oil-flooded screw compressor drives a pair of rotors at a rotational speed which is low enough not to increase torque for a short amount of time after start-up and accelerates the pair of rotors up to a normal-operation rotational speed after oil discharge. Alternatively, the oil-flooded screw compressor rotates the pair of rotors for a short amount of time after the remaining compressed gas is discharged after a halt, thereby allowing the oil accumulated inside the working chambers to be discharged and ensuring smooth start-up after the halt.