Contact sensor

 

(57) Abstract:

Usage: cleaning the contact electrodes of the sensor from contamination during operation in liquid media without removing the sensor and leaking joints. The inventive electrode sensor placed in the insulator, has an outer screw surface in contact with the working environment. This surface is associated with the internal helical surface of the sleeve is fixed in the insulator. The sleeve is made a longitudinal section and a transverse annular groove on the outer surface. In the groove of the installed spring washer. The electrode sleeve and washer are made of corrosion-resistant metal. Metal bushings are harder than the metal of the electrode. 2 C.p. f-crystals, 1 Il.

The invention relates to izmeritelnaya technique, namely the capacitance and conductivity measurement can be used to measure the interface, continuity of liquids in the petroleum, chemical, food, pharmaceutical, microbiological and other industries, as well as in agriculture and are able to operate in liquid environments in which on the surfaces of the electrodes stick and OSA the developers and users of these funds.

Known level switch containing the electrode with the measuring relay, indicator and oscillator [1] Since the cleaning of the electrode is carried out by means of vibration at the resonant frequency, this device is not designed for operation in liquid flows, creates turbulent eddies and leading to the disruption of the resonance oscillations of the electrodes. In addition, failure of the oscillations and termination cleanup will take place at the deposition, sticking clot of dirt.

Known purification method sensitive element uravneniya on author.St. USSR N 708163, CL G 01 F 23/26, in which cleaning is carried out by compressed air attached to the electrode elastic shell.

The disadvantages of the device that implements this method of treatment should be attributed to the low durability of the sheath material, solinet in the implementation of pressurized compressed air under the membrane, the need to have a source of compressed air. In addition, the measurement tool in this case cannot be conductivity type and is not suitable for use in conductive liquid environments.

A device for measuring the dielectric parameters of liquids by the author. St. USSR N 748220, CL G 01 N 27/22, adirenne with mechanism for reciprocating movement and which is simultaneously the piston and purifier of electrodes. This device works only in the pipelines and are not suitable for measuring fluid levels.

Famous adopted for the prototype, the electric-contact level sensor containing fluid in the form of a cylindrical pin and a stationary ring-shaped electrodes [2] the Movable electrode is connected with the drive of a reciprocating movement. Cleaning of the movable and fixed electrodes are knife edges of the rotating blades, oriented along the electrodes.

The disadvantages of the design of this sensor include the following:

when performing blade entirely of dielectric their knife edges will have a low resistance to wear and require periodic replacement blades;

when doing knife edges of the metal is one of the weak structural links of the sensor will be attaching them to the blades, taking into account the actual dimensions and weight of the latter, which would also affect the reliability and durability of the sensor;

simultaneous rotation of the blades and reciprocating movement of the electrode is carried out from the shared drive motor that generates during operation difficulties in maintaining both the maximum is Aya, bulky design, the large size and weight;

the design of the sensor is not designed for operation in liquid flows.

The invention is directed to the development of malogabaritnih sensor simple design that provides a reliable cleaning of the electrodes.

The essence of the invention lies in the fact that contact the sensor containing at least one movable electrode, placed in the isolator, the portion of the outer surface of the electrode which is in contact with the operating environment are made in the form of a helical surface that interacts with the response, mating internal helical surface of the bushing mounted stationary in the insulator. The sleeve is made a longitudinal section and a transverse annular groove on the outer surface, in which the spring washer. The movable electrode, the sleeve and the spring washer is made of corrosion-resistant metal, and the metal sleeve is greater than that of the metal electrode hardness.

The drawing shows the proposed sensor.

The sensor includes a housing 1, which has an insulator 2, for example, PTFE, in the body which, in the part that is in contact with the working environment, flush the pipeline section and the outer transverse annular groove, which is equipped with spring washer 4. The sleeve is fixed in the body of the insulator with three screws 5 without heads set flush with the outer surface of the insulator. The electrode 6 of the sensor on-site cut mating metric thread and he is screwed into the sleeve with a protrusion at its end. The reciprocating movement of the electrode is limited to one side ledge in prison, with another partition in the housing, and the length of the move is determined by the length of the work area. Case, the electrode, bushing, washer, and screws are made of corrosion-resistant metal and the hardness of the metal sleeve is higher than the hardness of the metal electrode. Seal joints between the sensor housing and accommodation, between the casing and the insulator between the insulator and the electrode is provided with a rubber ring 7.

Cleaning the working electrode piece is done when it is rotating clockwise and counterclockwise, causing the reciprocating movement of the working part of the electrode relative to the sleeve. Reliable and quality cleaning is done by friction forces that occur when moving spiral surfaces relative to each other. Thus the longitudinal slit in the sleeve and spring washer constantly oblasti when the movements of the piston area of the electrode.

The essential features of the invention:

the working area of the electrode in the form of an outer screw surface;

placing the working side of the electrode fixedly mounted in the insulator sleeve having mating internal screw surface;

the presence in the sleeve longitudinal section and a transverse outer annular groove in which is placed a spring washer;

the manufacture of the electrode, bushings and washers made of corrosion-resistant metal;

manufacturer of bushings made from metal with a greater degree of hardness than the metal of the electrode.

Thus, the proposed sensor involves an inventive step. i.e. set of features leads to a new device that provides the desired technical effect cleaning of the working part of the electrode from contamination that extends the functionality of the sensor when operating in liquid environments.

The sensor is provided by an Autonomous electrode cleaning without dismantling and leaking joints. The proposed sensor is easy to manufacture and maintain in operation, reliable in performance, has small dimensions and weight, able to work under pressure working environment to 2.0 MPa (20 kgf/cm

1. Contact sensor containing at least one movable electrode, placed in the insulator, wherein a portion of the electrode in contact with the working environment, has an outer screw surface and interfaced with internal helical surface of the sleeve is fixed in the insulator, and the sleeve is made a longitudinal section and a transverse annular groove on the outer surface, which includes a spring washer.

2. The sensor under item 1, characterized in that the electrode sleeve and washer are made of corrosion-resistant metal.

3. The sensor PP.1 and 2, characterized in that the metal sleeve has a higher degree of hardness than the metal of the electrode.

 

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