CN101334301A

CN101334301A - Vortex shedding flowmeter

Info

Publication number: CN101334301A
Application number: CNA2008100394421A
Authority: CN
Inventors: 颜建渭; 陈宝荣
Original assignee: Shanghai Xingkong Automation Instrumentation Co Ltd
Current assignee: Shanghai Xingkong Automation Instrumentation Co Ltd
Priority date: 2008-06-24
Filing date: 2008-06-24
Publication date: 2008-12-31

Abstract

The invention discloses a novel vortex shedding flowmeter which comprises a shell internally provided with a vortex generator, a sensor provided with a probe, a connecting bar and an integrating meter. The shell is connected with the integrating meter by the connecting bar which is internally provided with the sensor, one end of the sensor is connected with the integrating meter, while the other end thereof is connected with the probe which is accessed into the interior of the shell, wherein, the inner chamber of the probe shell is directly provided with a piezoelectric ceramic plate, leading one end of the piezoelectric ceramic to be clung to the bottom of the inner chamber of the probe shell; a connecting plate is tightly clung to the other end of the piezoelectric ceramic and insulated with the probe shell; a bale tightly presses the piezoelectric ceramic plate, insulation materials are arranged between the piezoelectric ceramic and the bale, the bale and the shell are welded into a whole or tightly fit with each other; two flow signal conducting wires are respectively led out from the bale and the connecting plate; the central cavity of the probe is provided with a platinum resistor or a thermocouple temperature sensor, leads out two temperature signal wires at the same time, and is provided with a close over which is sintered by organic glass and used for encapsulating the central cavity of the probe and four lead wires.

Description

Novel vortex street flowmeter

Technical field:

The present invention relates to the industrial automation field, the incorporate novel vortex street flowmeter of particularly a kind of temperature compensation.

Background technology:

Stress-type vortex street flowmeter is a kind of fluid oscillation formula new flowmeter, when medium flows through triangular prism vortex generation body with certain speed, produces a vortex band of alternately arranging in back, triangulo column both sides, is referred to as " Karman vortex street ".Because triangular prism vortex generation body both sides alternately produce vortex, so the generation pressure fluctuation of body both sides is taking place, thereby make the detection bodies probe produce alterante stress, be encapsulated in the interior piezolectric crystal unit of sonde body under the effect of alterante stress, produce alternation charge signal with the vortex same frequency, amplifier with this charge signal amplify, filtering, shaping, the pulse signal that last output frequency is directly proportional with velocity of medium is delivered to integrating instrument and is processed and displayed.It has that measurement range is wide, crushing is little, stable performance, accuracy is high and advantage such as easy to install; Be widely used in sealing the measurement of liquid in the industrial pipeline, gas and steam medium volumetric flow rate.

But, when the current industrial automatic field uses vortex shedding flow meter to measure steam, because what the vortex shedding flow meter of producing on the market itself recorded is volumetric flow rate, and steam often takes in mass in the trade settlement, for volumetric flow rate is converted into quality, often need to finish by complicated, loaded down with trivial details technological process; Can not be with temperature compensation again when measuring liquid.

The structure of existing vortex shedding flow meter as shown in Figure 1, by the housing a1 that has sensor vortex generation body, probe a2, connecting rod a3, integrating instrument a4 forms.Wherein, pop one's head in a2 as shown in Figure 2, this structure is a pair of piezoelectric ceramic piece a22 to be sticked on probe plug a23 go up among the back insertion probing shell a21, fills the organic resin inserts at housing a21 inner chamber a24 then.Facts have proved and have following problem:

(1) this structure piezoelectric ceramics a22 is vertical the placement, the be subjected to force direction of flow signal on piezoelectric ceramics is the pipe level direction, and industrial pipeline vibration interference signal also is the pipe level direction, the pipe vibration undesired signal of horizontal direction is superimposed on the effective discharge signal of horizontal direction, be difficult for the useful flow signal of difference, undesired signal, so flowmeter disturbs big, resistance to shock is poor.

(2) this structure is because of adopting the encapsulation of organic resin inserts, very easily aging, under the special long term high temperature situation, organic resin is aging to be peeled off, moisture enters probing shell inner chamber a23, and the piezoelectric ceramics that causes popping one's head in insulation descends and damages, and organic resin shrinks and causes piezoelectric ceramic piece a22 to break away from plug a23 sometimes, so this structure probe life-span is short, high-temperature behavior is poor;

(3) the insertion pipe section a25 of this structure probing shell a21 is because inner chamber is empty, tube wall is thin, probe segment a25 often takes place and fractures and washed away by fluid media (medium) in the pipeline together with piezoelectric ceramics a22 in fluid impact probe segment a25 in the pipeline in the use, and serviceable life is short.

In addition, the integrated vortex shedding flow meter of a kind of band temperature compensation is also disclosed in the prior art (referring to China Patent No.: ZL 200620048917.x), its feature is that flow probe and temp probe separate, temp probe one termination is gone into the vortex shedding flow meter enclosure interior, and adopt the external power power supply, more complicated on the structure.

Summary of the invention:

In view of above-mentioned technical matters, by vortex shedding flow meter is popped one's head in force way, packaging technology, done great innovation, problem to be solved by this invention has provided a kind of high temperature resistant, anti-seismic performance is good, have temperature compensation, can measure the isoparametric novel vortex street flowmeter of volumetric flow rate, mass rate, cost of use and the balance of funding of liquid, gas, steam.This device is located at flow sensor and temperature sensor in the same probe, and power supply power supply in relying on, and does not join temperature transmitter outside not needing, and does not need wiring, and structure is more simple, and cost is lower, installs and uses more convenient.So, thoroughly changed the shortcoming that vortex shedding flow meter can not directly not measured mass rate.

Technical matters solved by the invention can realize by the following technical solutions:

Novel vortex street flowmeter comprises the housing of built-in vortex generation body, the sensor that has probe, connecting rod, integrating meter; Be connected by connecting rod between housing and the integrating meter; Connecting rod inside is provided with an end and connects integrating meter, and the other end connects the sensor that inserts the enclosure interior probe.

Wherein, the inner chamber of probing shell is directly put into piezoelectric ceramic piece, makes piezoelectric ceramics one end be attached to the bottom of probing shell inner chamber; Be close to the piezoelectric ceramics other end by the line plate, and insulate with probing shell; Briquetting presses potsherd, places insulating material between piezoelectric ceramics and briquetting, and briquetting and housing are welded as a whole or wringing fit; Two flow signal leads and drawing from briquetting and terminal block respectively; Place platinum resistance or thermocouple temperature sensor in the center probe cavity, draw two temperature signal lines simultaneously, and be provided with the capping of the organic glass sintering that is used for encapsulating center probe cavity and four lead-in wires.

In addition, the circuit structure of this vortex shedding flow meter is by single-chip microcomputer, and with 3V lithium battery that this single-chip microcomputer is connected respectively in power supply current supply circuit, temperature acquisition loop, amplify shaping loop, keyboard loop, LED show circuit and constitute.

Beneficial effect of the present invention is as follows:

(1) piezoelectric ceramics 3 is a horizontal positioned, it is the above-below direction of vertical pipe that flow signal is subjected to force direction, and industrial pipeline vibration interference signal is the pipe level direction, the pipe vibration undesired signal of horizontal direction can not be superimposed on the effective discharge signal of vertical direction, distinguished useful signal effectively, undesired signal has strengthened the resistance to shock of vortex shedding flow meter on the principle greatly.

(2) on the piezoelectric ceramics 3 for insulating material 4 and briquetting 6 compress, the organic resin that can not produce general probe usefulness is filled aging, phenomenons such as deformation, the reliability height, heat resistance is good.

(3) lead terminal capping place organic glass sintering is high temperature resistant, is difficult for aging.

(4) probe internally provided temperature sensor 10 provides temperature signal to integrating instrument.

(5) be solid Stainless Steel, not frangibility with the probe segment 14 that medium directly contacts.

(6) envelope has piezoelectric ceramics and platinum resistance or thermal resistance temperature to become sensor in the probe, can provide flow signal and temperature signal to integrating instrument simultaneously, integrating instrument is built-in with temperature-density form, calculate demonstration volumetric flow rate and mass rate, and can calculate demonstration cost of use, the balance of funding trade parameters such as (Renminbi) as required.

Description of drawings:

Further specify the present invention below in conjunction with the drawings and specific embodiments.

Fig. 1 is for there being technology vortex shedding flow meter structural drawing.

Fig. 2 has the section of structure of popping one's head in the technology vortex shedding flow meter for shown in the last figure.

Fig. 3 is a vortex shedding flow meter structural drawing of the present invention.

Fig. 4 is a sonde configuration sectional view in the vortex shedding flow meter of the present invention.

Fig. 5 is a vortex shedding flow meter schematic block circuit diagram of the present invention.

Embodiment:

For technological means, creation characteristic that the present invention is realized, reach purpose and effect is easy to understand, below in conjunction with concrete diagram, further set forth the present invention.

As shown in Figure 3, novel vortex street flowmeter of the present invention, comprise built-in vortex generation body housing 1, have probe 2 sensor, connecting rod 3, integrating meter 4; Be connected by connecting rod 3 between housing 1 and the integrating meter 4; Connecting rod 3 inside are provided with an end and connect integrating meter 4, and the other end connects the sensor that inserts housing 1 inner probe 2.

As shown in Figure 4, the inner chamber 22 of probing shell 21 is directly put into piezoelectric ceramic piece 23, make piezoelectric ceramics 23 1 ends be attached to the bottom of probing shell inner chamber 22, be close to piezoelectric ceramics 23 other ends by line plate 25, and with probing shell 21 insulation, briquetting 26 presses potsherd 23, between piezoelectric ceramics 23 and briquetting 26, place insulating material 24, briquetting and housing are welded as a whole or wringing fit,

flow signal lead

27 and 28 is drawn from briquetting 26 and terminal block 23 respectively, places platinum resistance or thermocouple temperature sensor 210 in the center probe cavity 29, measures temperature signal, temperature signal line 211,212 draw from 210,213 are capping, with organic glass sintering encapsulation cavity 29 and lead-in wire, prevent that moisture from entering cavity 29, organic glass fusing point height, high temperature resistant.

Referring to Fig. 5, as for the circuit structure of this vortex shedding flow meter by single-chip microcomputer, and with 3V lithium battery that this single-chip microcomputer is connected respectively in power supply current supply circuit, temperature acquisition loop, amplify shaping loop, keyboard loop, LED show circuit and constitute.

The operational process of whole device is: probe 2 is converted to pulse signal by built-in piezoelectric ceramics with flow signal, record temperature signal by built-in temperature sensor, flow signal and temperature signal are delivered to integrating meter 4 together, integrating meter 42 pulse signals of will popping one's head in are amplified Weak pulse signal that the flux of vortex street probe comes by " amplifying; the shaping loop ", shaping is sent in the PIC single-chip microcomputer and is counted, " temperature acquisition loop " collecting temperature signal in real time sends into the PIC single-chip microcomputer, " keyboard loop " is the software operation key circuit, " power supply current supply circuit in the 3V lithium battery " provides the complete machine working power, single-chip microcomputer adopts PIC ultra low-power microcontroller PIC16C73, integrating instrument is built-in with temperature-density form, calculate and show volumetric flow rate and mass rate (m=ρ V at LCD, the m-mass rate, ρ-Media density, the V-volumetric flow rate), and can calculate demonstration cost of use, remaining sum as required.

For example: during trade is calculated, steam price x=2 unit/ton, cost of use A=xm, the remaining sum B=volume of supplementing with money-cost of use A (wherein m is the steam mass flow that vortex shedding flow meter records).

More than show and described ultimate principle of the present invention and principal character and advantage of the present invention.The technician of the industry should understand; the present invention is not restricted to the described embodiments; that describes in the foregoing description and the instructions just illustrates principle of the present invention; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the claimed scope of the invention.The claimed scope of the present invention is defined by appending claims and equivalent thereof.

Claims

1, novel vortex street flowmeter comprises the housing of built-in vortex generation body, the sensor that has probe, connecting rod, integrating meter; Be connected by connecting rod between housing and the integrating meter; Connecting rod inside is provided with an end and connects integrating meter, and the other end connects the sensor that inserts the enclosure interior probe; It is characterized in that the mechanism of described probe is that the inner chamber of housing is directly put into piezoelectric ceramic piece, makes piezoelectric ceramics one end be attached to the bottom of probing shell inner chamber; Be close to the piezoelectric ceramics other end by the line plate, and insulate with probing shell; Briquetting presses potsherd, places insulating material between piezoelectric ceramics and briquetting, and briquetting and housing are welded as a whole or wringing fit; Two flow signal leads and drawing from briquetting and terminal block respectively; Place platinum resistance or thermocouple temperature sensor in the center probe cavity, draw two temperature signal lines simultaneously, and be provided with the capping of the organic glass sintering that is used for encapsulating center probe cavity and four lead-in wires.

2, according to the vortex shedding flow meter of claim 1, it is characterized in that, described circuit structure is by single-chip microcomputer, and with 3V lithium battery that this single-chip microcomputer is connected respectively in power supply current supply circuit, temperature acquisition loop, amplify shaping loop, keyboard loop, LED show circuit and constitute.