CN201876293U

CN201876293U - Capacitance induction type material level detector

Info

Publication number: CN201876293U
Application number: CN201020210558XU
Authority: CN
Inventors: 董福贵; 崔鹏旭; 张景瑞
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-05-21
Filing date: 2010-05-21
Publication date: 2011-06-22
Anticipated expiration: 2020-05-21

Abstract

The utility model provides a capacitance induction type material level detector which consists of an induction electrode, an oscillating circuit, a frequency/voltage (F/V) conversion circuit, a signal processing circuit and a switching value output circuit. When material to be detected is close to a capacitance induction surface, the capacitance between electrode plates is changed, a changed capacitance signal is transmitted to each circuit to be converted, and a switching value signal is output and is transmitted into a distributed control system (DCS) or a programmable logic controller (PLC) for controlling the displaying of an acousto-optic alarm. The detector has the advantages that the structure is simple, the applicable scope is wide, the maintenance is little, the sensitivity is high, the dynamic response characteristic is good, the load resistance capability is large, the price is low, the dust prevention, the corrosion resistance and the low temperature resistance are realized, the installation position is not affected by the environment, etc. The detector adopts a capacitance induction technology, is not provided with complex electric circuits and mechanical driving components, therefore, various malfunctions can be avoided, the work performance of the detector is extremely reliable, the complex debugging can be avoided, the installation and the maintenance are easy, and the detector can continuously run for a long time.

Description

The capacitor induction type material-level detecting device

Technical field

The present utility model belongs to a kind of pick-up unit, particularly relates to a kind of capacitor induction type material-level detecting device.

Background technology

The detection of the height of the material level in solid material (particulate material, powder) storehouse; basically all be to adopt the blocking rotary type level-sensing device to detect the height of control material level in the robotization context of detection at present; when material level reaches the height of technological requirement; the closing of contact or the disconnection of blocking rotary type level-sensing device switch are sent alerting signal and are come alert note the going forward side by side interlocking action protection of line correlation.But just the prior art situation and the instrumentation itself of blocking rotary type level-sensing device still exist many defectives and deficiency at present, such as: (1) is in measuring testing process, the material foam of material can often immerse in the sealing ring of coupling shaft, and the rotation that makes coupling shaft is blocked and can not be rotated freely, cause coupling shaft to lose rotating function and make instrument malfunction, and then make instrument lose the effect that detects control.(2) because blocking rotary type level-sensing device switch adopts the rotation of 220VAC power supply motor driven rotor, and the power supply of 220VAC power supply may damage human body, has insecurity, has unsafe factor.(3) the blocking rotary type level-sensing device adopts the 220VAC power supply, and power consumption is big, increases enterprise's production cost.(4) blocking rotary type level-sensing device volume of switch is big, and is relatively heavier, is not easy to regular job and maintenance work, increases maintainer's labour intensity.(5) it is charged that blocking rotary type level-sensing device switch adopts the little microswitch zonula occludens of mechanical type motor type relay, closing of contact output node signal, reach the purpose of material level control, and the mechanical type fine motion is opened and is easy to damage and misoperation, also there are phenomenons such as loose contact and node wear out in relay contact, and in whole control loop, have the generation of the misoperation or the phenomenon of being failure to actuate, having a strong impact on ordinary production and safety in production.

Summary of the invention

The present utility model is intended to overcome the deficiencies in the prior art, and a kind of capacitor induction type material-level detecting device simple in structure, sensitive is provided.

The technical scheme that the present utility model adopted is: the capacitor induction type material-level detecting device, comprise cask flask, induction electrode, oscillatory circuit, F/V translation circuit, signal processing circuit and switching value output circuit, it is characterized in that: capacitive sensing probe is to measured object, induction electrode volume change signal is delivered to oscillatory circuit, and the frequency inverted of oscillatory circuit becomes voltage signal to deliver to the signal processing circuit voltage signal processed to deliver to the switching value output circuit and export.

The condenser type material-level detecting device is made of two coaxial metal electrodes, resemble very much the electrode for capacitors of " opening ", these two electrodes constitute a capacitor, be serially connected in the RC oscillatory circuit, during power connection, RC oscillator nonoscillatory, when an objective body or material touch capacitor, capacitor volume increases, oscillator begins to shake, and the processing by the back polar circuit converts depressed or the two kinds of signals that vibrate to switching signal respectively, detect the purpose that has or not object to exist thereby reach, play control action.

Capacitor induction type level-sensing device pick-up unit of the present utility model adopts the 24VDC power supply, and 24VDC belongs to safe voltage, and human body and equipment are all had protective effect; and owing to adopt the 24VDC power supply, consumed power is little, reaches energy-saving effect; reduce production costs, improve the business economic benefit.

The utility model has adopted the capacitance sensing detecting device as the detecting element to height of materials; when the rising of feed bin material charge level reaches the set upper limit height of technological requirement; detecting element is subjected to blocking of material; and capacitive transducer sends the signal of a closure or disconnection; be transported among the DCS or PLC in the pulpit; carry out sound and light alarm; carry out the automatic interlock protection simultaneously; stop to carry out convey materials to feed bin; or start the conveying program of material automatically; the material of this feed bin is outwards carried, and when the material face dropped to feed bin lower limit height, capacitive transducer sent the signal of a closure or disconnection; being sent to DCS or PLC is to carry out sound and light alarm; simultaneously, carry out automatic interlock control protection, stop the outside convey materials of this feed bin or start the outside simultaneously carrying out convey materials to this feed bin.

The beneficial effects of the utility model are: applied widely, can powder, particulate material and the lump material in opening feed bin, the airtight feed bin be detected, and report to the police and control automatically.Can be widely used in the actual industrial production such as electric power, iron and steel, building, petrochemical complex, grain, medicine and food.Its advantage: simple in structure, maintenance is little, has advantages such as good dust-proof, anticorrosion, antidetonation, shock-resistant, low temperature resistant and stable work in work.

The utility model is owing to adopted the capacitive sensing sensing technology, there is not complicated electric wiring, do not have any mechanical component and then avoided the appearance of various misoperations, make that the performance such as material level control, warning of capacitor induction type pick-up unit is very reliable, need not complicated the adjustment, install simply, for ease of maintenaince, not influenced by rugged surroundings, long-time running continuously.

Description of drawings

Figure of description is a capacitor induction type material-level detecting device structural representation of the present utility model.

Embodiment

The capacitor induction type material-level detecting device, comprise cask flask 1, induction electrode 2, oscillatory circuit 4, F/V translation circuit 5, signal processing circuit 6 and switching value output circuit 7, it is characterized in that: capacitive sensing probe is to measured object 3, induction electrode 2 volume change signals are delivered to oscillatory circuit 4, and the frequency inverted of oscillatory circuit 4 becomes voltage signal to deliver to signal processing circuit 6 voltage signal processed to deliver to switching value output circuit 7 and export.

The detection mode principle of work of capacitor induction type detection probe:

The utility model belongs to a kind of position model pick-up unit with switching value output, when detected material 3 during near induction electrode 2, the electric capacity of input circuit induction electrode 2 is changed, the electric capacity signal that changes is transferred to oscillatory circuit 4, make oscillatory circuit 4 produce vibration, frequency signal after the vibration is sent to F/V translation circuit 5 and carries out the conversion of frequency and voltage signal, voltage signal after the conversion is delivered to switching value output circuit 7 through signal processing circuit 6 and is carried out switching value output, its contact action, thereby reach the purpose of controlling alarm, realize the purpose of material level control.

Claims

1. capacitor induction type material-level detecting device, comprise cask flask (1), induction electrode (2), oscillatory circuit (4), F/V translation circuit (5), signal processing circuit (6) and switching value output circuit (7), it is characterized in that: capacitive sensing probe is to measured object (3), induction electrode (2) volume change signal is delivered to oscillatory circuit (4), and the frequency inverted of oscillatory circuit (4) becomes voltage signal to deliver to signal processing circuit (6) voltage signal processed to deliver to switching value output circuit (7) and export.