摘要:
A method and apparatus for detection of clogging of an orifice by measuring the upstream side pressure without breaking up the piping system in a flow rate control unit using an orifice, so as to extend the life of the flow rate control unit and enhance its safety. The apparatus of detecting clogging of an orifice in a pressure-type flow rate controller has a control valve (CV), an orifice (2), a pressure detector (14) for measuring the upstream pressure P1 therebetween, and a flow rate setting circuit (32) wherein, with the upstream pressure P1 maintained about two or more times higher than the downstream pressure P2, the downstream flow rate QC is calculated with the equation QC=KP1 (K=constant) and wherein the control valve (CV) is controlled by the difference signal QY between the calculated flow rate QC and the set flow rate QS. The apparatus comprises: a storage memory M memorizing standard pressure attenuation data Y(t) of the upstream pressure P1 measured with the flow rate switched from the high set flow rate QSH to the low set flow rate QSL with the orifice (2) not clogged, a pressure detector (14) for determination of the pressure attenuation data P(t) of the upstream pressure P1 with the flow rate switched from the high set flow rate QSH to the low set flow rate QSL with the orifice (2) in the actual conditions, a central processing unit CPU for checking the pressure attenuation data P(t) against standard pressure attenuation data Y(t), and an alarm circuit (46) that turns on a clogging alarm when the pressure attenuation data P(t) deviates from standard pressure attenuation data Y(t) to a specific degree or beyond that.
摘要:
An improved and reduced-size and low-cost gas supply system equipped with a pressure-type flow rate control unit, to be used, for instance, in semiconductor manufacturing facilities is disclosed. Transient flow rate characteristics are improved to prevent the gas from overshooting when the gas supply is started, and to raise the flow rate control accuracy and reliability of facilities. That eliminates non-uniformity of products or semiconductors and raises the production efficiency. The gas supply system equipped with a pressure-type flow rate control unit is so configured that with the pressure on the upstream side of the orifice held about twice or more higher than the downstream side pressure, the gas flow rate is controlled to supply the gas to a gas-using process through an orifice-accompanying valve, the gas supply system comprising a control valve to receive gas from the gas supply source, an orifice-accompanying valve provided on the downstream side of the control valve, a pressure detector provided between the control valve and the orifice-accompanying valve, an orifice provided on the downstream side of the valve mechanism of the orifice-accompanying valve and a calculation control unit where on the basis of the pressure P1 detected by the pressure detector, the flow rate Qc is calculated with an equation Qc=KP1 (K: constant) and the difference between the flow-rate specifying signal Qs and the calculated flow rate Qc is then input as control signal Qy in the drive for the control valve, thereby regulating the opening of the control valve for adjusting the pressure P1 so that the flow rate of the gas to supply can be controlled.
摘要:
A fluid supply apparatus with a plurality of flow lines branching out from one pressure regulator with the flow lines arranged in parallel and constructed so that opening or closing one flow passage will have no transient effect on the steady flow of the other flow passages. Each flow passage is provided with a time delay-type mass flow controller MFC so that when one closed fluid passage is opened, the mass flow controller on that flow passage reaches a set flow rate Qs in a specific delay time Δt from the starting point.The invention includes a method and an apparatus in which a plurality of gas types can be controlled in flow rate with high precision by one pressure-type flow control system.
摘要:
A fluid supply apparatus with a plurality of flow lines branching out from one pressure regulator with the flow lines arranged in parallel and constructed so that opening or closing one flow passage will have no transient effect on the steady flow of the other flow passages. Each flow passage is provided with a time delay-type mass flow controller MFC so that when one closed fluid passage is opened, the mass flow controller on that flow passage reaches a set flow rate Qs in a specific delay time At from the starting point. The invention includes a method and an apparatus in which a plurality of gas types can be controlled in flow rate with high precision by one pressure-type flow control system.
摘要:
A fluid supply apparatus with a plurality of flow lines branching out from one pressure regulator with the flow lines arranged in parallel and constructed so that opening or closing one flow passage will have no transient effect on the steady flow of the other flow passages. Each flow passage is provided with a time delay-type mass flow controller MFC so that when one closed fluid passage is opened, the mass flow controller on that flow passage reaches a set flow rate Qs in a specific delay time &Dgr;t from the starting point. The invention includes a method and an apparatus in which a plurality of gas types can be controlled in flow rate with high precision by one pressure-type flow control system.
摘要:
A method of detecting abnormalities in flow rate in pressure-type flow controller. The method checks the flow rate for abnormalities while controlling the flow rate of fluid in a pressure-type flow controller FCS using an orifice—the pressure-type flow controller wherein with the upstream pressure P1 maintained about two or more times higher than the downstream pressure P2, the downstream flow rate QC is calculated by the equation QC=KP1 (K: constant) and wherein the control valve CV is controlled on the basis of the difference signal QY between the calculated flow rate QC and the set flow rate QS.
摘要:
A construction for mounting a pressure detector prevents the detector diaphragm from being strained by stress applied to the pressure detector as the detector is mounted in a fixture main body provided in a pipe line or the like, thereby keeping the output characteristics and temperature characteristics of the detector from greatly differing before and after the mounting. The pressure detector is constructed by combining and fastening together a diaphragm base having a diaphragm and a sensor base having a sensor element therein that is activated by displacement of the diaphragm base. The pressure detector, with a gasket placed thereunder, is disposed in a mounting hole of a fixture main body that is mounted in a pipe line. The pressure detector is air-tightly pressed and fastened by a presser member inserted from above in the mounting hole. The presser member is brought in contact with a block upper surface of the diaphragm base, and the gasket is also brought in contact with the block lower surface of the diaphragm base. A shallow groove is defined in the form of a ring on the lower surface of the block at a place inward of the portion contacting the metal gasket so that the shallow groove absorbs strain caused by the presser member.
摘要:
A valve with an integral orifice for use in gas feeding equipment provided with a pressure-type flow volume control device to be employed for manufacturing of semi-conductors and chemical goods. The valve with an integral orifice has the excellent flow rate control characteristics by improving the processing accuracy of the orifice and preventing the distortion of the orifice at the time of assembling. The orifice is formed in a stainless steel made orifice disc. The metal-made orifice disc with the orifice formed by separate processing and the synthetic-resin-made valve seat body are removably assembled, wherein the orifice disc and the synthetic resin made valve seat body are fixed airtight to the valve main body by pressing the valve seat body via a metal inner disc.
摘要:
A valve with an integral orifice for use in gas feeding equipment provided with a pressure-type flow volume control device to be employed for manufacturing of semi-conductors and chemical goods. The valve with an integral orifice has the excellent flow rate control characteristics by improving the processing accuracy of the orifice and preventing the distortion of the orifice at the time of assembling. The orifice is formed in a stainless steel made orifice disc. The metal-made orifice disc with the orifice formed by separate processing and the synthetic-resin-made valve seat body are removably assembled, wherein the orifice disc and the synthetic resin made valve seat body are fixed airtight to the valve main body by pressing the valve seat body via a metal inner disc.
摘要:
A valve with an integral orifice for use in gas feeding equipment provided with a pressure-type flow volume control device to be employed for manufacturing of semi-conductors and chemical goods. The valve with an integral orifice has the excellent flow rate control characteristics by improving the processing accuracy of the orifice and preventing the distortion of the orifice at the time of assembling. The orifice is formed in a stainless steel made orifice disc. The metal-made orifice disc with the orifice formed by separate processing and the synthetic-resin-made valve seat body are removably assembled, wherein the orifice disc and the synthetic resin made valve seat body are fixed airtight to the valve main body by pressing the valve seat body via a metal inner disc.