Integrated magnetic suspension flow controller

Abstract

The invention discloses an integrated magnetic suspension flow controller. The base, the cavity cylinder and the upper cover are tightly assembled and define a main cavity, and an ultra-clean floater is arranged in the main cavity. A driving magnetic circuit is arranged on the periphery of the main cavity; a suspension magnetic circuit is arranged above and below the driving magnetic circuit; in the driving magnetic circuit, a driving motor is arranged on an upper cover, an output shaft of the driving motor is connected with a lead screw, the lead screw is externally connected with a connecting bracket through a T-shaped sliding sleeve, and an outer permanent magnet and a suspension magnetic circuit are arranged below the connecting bracket; the suspension magnetic circuit comprises suspension assemblies above and below the outer permanent magnet; the suspension assembly comprises a circuit board, a suspension coil group formed by suspension coil windings, and a Hall sensor group. The floater serves as an execution control valve for flow control, the displacement difference of the floater relative to the outer magnet under the impact of incoming flow serves as a flow feedback signal to achieve closed-loop control of the flow, the size is reduced, and the cleanliness of fluid is guaranteed; the problem that the initial detection flow of a traditional float flowmeter is too large due to radial wall-attached friction is solved.

Description

technical field [0001] The invention relates to a flow controller and a control method in the technical field of flow measurement and control, in particular to an integrated magnetic levitation flow controller and a control method suitable for ultra-clean occasions. Background technique [0002] Semiconductor, biomedicine, electronic grade chemical industry and other fields are very sensitive to pollutants such as particulate matter and ions, and put forward very high cleanliness requirements for liquids or gases required for production processes. Materials or processes that meet a certain standard of cleanliness are called super cleanliness. Clean materials or ultra-clean processes. The flow control components that transport ultra-clean fluid media must strictly prevent the internal medium from communicating with the outside world, and must be safe, reliable and corrosion-resistant. At the same time, the flow control components themselves must not produce wear and particles...

AI Technical Summary

Problems solved by technology

[0003] In the fields that require ultra-clean fluid or corrosive fluid transmission and control, the commonly used ultra-clean flow controller is generally a series connection of an ultra-clean flow meter and an ultra-clean valve. Due to the need to meet the requirements of no wear and particles, and to strictly prevent the internal medium from communicating with the outside world, the selected ultra-clean flowmeter is generally a fully enclosed ultrasonic flowmeter or Venturi flowmeter with no moving parts, and its structure is more complicated; Diaphragm valves are generally used for ultra-clean control valves, and ultra-clean resin materials are processed into flexible diaphragms to control the opening of the valve port. During long-term adjustment and actuation, the diaphragm will face the risk of rupture due to long-term high-cycle fatigue, and diaphragm rupture The consequence of leakage of the medium is very serious.

In addition, in these examples, the flowmeter as a feedback sensor and the control valve as an actuator are separated from each other, which increases the overall space volume and limits its application in small spaces (such as semiconductor machines in small spaces). device) application

[0004]On the other hand, the traditional rotameter has the advantages of compact structure, small size, and easy calibration; and other problems, the resulting particles will contaminate the ultra-pure liquid medium, and at the same time, the wall friction will increase the initial flow rate at small flow rates and reduce the resolution of the sensor

The traditional cone valve has the advantages of compact structure, reliable fatigue performance, and good flow control linearity; The risk of external leakage caused by the sealing gap seriously restricts the application of the cone valve in the field of ultra-clean flow control

Images