Precession vortex gas meter

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ZW series - LUXPrecession vortex gas meterIs the use of advanced double probe precession flow sensor…

ZW series - LUXPrecession vortex gas meterIs the use of advanced double probe precession flow sensor technology, strong anti-jamming capability, high precision, no mechanical moving parts, not easy corrosion, compact structure, high reliability, good stability, small amount of maintenance., has powerful function, wide flow range, simple operation and maintenance, and installation of the advantages of easy to use, because of its uniqueness, that it must constantly in the process of development to adapt to the development of mechanical manufacturing level, main technical indexes reach the advanced level of similar foreign products of new type of gas flow meter.

Second, the working principle:

ZW series - LUX precession vortex gas meter is when a fluid through composed of spiral vane vortex generator, fluid is forced to around the dramatic rotating body axis, form a spiral.When fluid into the diffuser, vortex flow under the effect of reflux, began as a secondary rotation, form the gyro type vortex precession phenomenon.The precession frequency is proportional to the flow size, not influenced by the physical properties and fluid density.Detecting element quadratic spin precession frequency measured fluid, knew the traffic.And in a relatively wide flow rate range for good linearity.Flowmeter formula is: K = f/q

Type: K - l/m&sup 3 flow meter coefficient

F - vortex frequency Hz

Q - volume flow m&sup 3;/ s

The instrument coefficient of flow meter in certain structural parameters and the specified within the scope of Reynolds number and the fluid temperature, pressure, composition and physical properties (density, viscosity) has nothing to do.

Applications:

ZW series - LUX precession vortex gas meter adopting new micro processing technology, with strong functions, wide flow rate range, simple operation and maintenance, and convenient to install and use etc, and the main technical indexes reach the advanced level of the same products abroad.It is widely used in petroleum, chemical industry, electric power, metallurgy, coal, etc all kinds of gas measurement.

Four, vortex precession flowmeter by the following seven basic parts (figure 1) :

Precession vortex flowmeter structure

1, vortex occurred

Made of aluminum alloy, with a certain Angle spiral blade, it is fixed at the front of the housing contraction, forcing fluid produced strong vortex flow.

2, shell

Itself with the flange, the shape of the fluid channel and to a certain extent, according to the different working pressure and shell material can be cast aluminum alloy or stainless steel.

3, intelligent flowmeter integrating instrument

By the temperature, pressure testing analog channel, flow digital channels and micro processing unit, LCD driver circuit and other auxiliary circuit composition, and equipped with transmission signal interface.

4, temperature sensor

Pt100 / pt1000 platinum resistor as the temperature sensitive element, in a certain temperature range, the resistance value and temperature into corresponding relation.

5, pressure sensor

With diffused silicon piezoresistive type bridge road as the sensitive element, the bridge arm resistance will happen under outside pressure is expected to change, therefore under certain excitation current, its two outputs potential difference is proportional to the pressure.

6, piezoelectric crystal sensors

Near the shell expansion period of throat, can detect the frequency signal of vortex precession.

7, disappear is investigated

Fixed in the shell outlet, its function is to eliminate vortex flow, to reduce the impact on downstream instrument performance.

Five, the meter is composed of sensor and conversion display.

1, sensors, including vortex generator, detecting element, rectifier and shell.

Vortex generator is composed of specific spiral blade, it fixed in the housing contraction front, forcing fluid produced strong vortex flow.

The throat of detecting element near the expansion pipe with thermal, piezoelectric, strain, or optical detecting element to measure the frequency signal of vortex precession.

Rectifier is fixed in the meter body exports, its function is to eliminate vortex flow, to reduce the influence of downstream flow pattern for instrument measurement.

Shell design into a certain shape of flow channel, to form vortex, fixed and protection is installed in the internal parts and components, and by pipeline flange connection.

2, transform, display

By piezoelectric sensors detect the weak voltage signal after amplification, filtering, plastic into frequency is proportional to the flow of the pulse signal, and then by the display counter.Display is equipped with a transmission interface, the output signals.To measure gas medium temperature and pressure compensation, can be converted into standard volume flow conditions, and display.

3, the structure composition:

ZW - LUX series compact structure, and is mainly composed of shell, the vortex occurred body, sensors (temperature, pressure, flow), rectifier, bracket and converter.

Six, the main features:

1, built-in pressure, temperature, flow sensor, safety performance is high, compact structure, beautiful appearance;

2, in situ show that temperature, pressure, the instantaneous flow and cumulative flow;

3, a new signal processing amplifier and unique filtering technology, effectively eliminate the pressure fluctuation and pipeline vibration produced by the jamming signal, greatly improve the anti-interference ability of the flowmeter, small flow have excellent stability;

4, the characteristic time display and real-time data storage function, no matter what circumstance, can guarantee the internal data is not lost, may be retained * sex;

5, the machine power consumption is extremely low, can run on battery power for a long time in, is the ideal without external power supply on-site display instrument;

6, anti-theft functions and reliable, with password protection, prevent parameter changes;

7, free rotation headers can be 180 degrees, convenient installation.

Seven, the technical parameters:

1, flowmeter specification, basic parameters:

Note: a. the flow range of products listed in the table when the verification of the flow range (temperature, air pressure medium for P = 1.205 Kg/m3);B. with the increase of pressure, flow range is expanding.

2, the standard state situation: P = 101.325 kPa, T = 293.15 K;

3, the conditions of use:

A, environmental temperature: - 30 ~ + 60 ℃;

B, medium temperature: - 20 ~ + 80 ℃;

C, relative humidity: 5% ~ 95%;

D, atmospheric pressure: 86 kpa to 106 kpa.

4, electrical performance indicators:

Outside a, working power supply: power supply: + 24 VDC;

B, within the power supply: 3.6 V lithium batteries;

C, the whole machine energy consumption: external power, < 1 w power supply, < 0.3 mW, lithium battery can be used at least 2 years;

D, the output mode: frequency signal;

: e, 4 ~ 20 ma current signal corresponding to the flow of 0 ~ Qmax, 20 ma, corresponding flow can be set by users themselves;

F, RS485 communication: can transfer temperature, pressure, the instantaneous flow and cumulative flow parameters;

5, explosion-proof marks: Exd Ⅱ BT4;

6, protection grade: IP65.

Eight, fault phenomenon and solution:

1 meter, flowmeter show temperature and pressure is normal, no instantaneous flow display

Reasons: (1) meter selection is too big, no flow selection will cause flowmeter.Solution: one is the lower limit cut-off frequency lower flowmeter (such flowmeter can be used, but will cause the meter accuracy reduce).2 it is to replace the small specification flowmeter.

(2) : no current input preamplifier.No power supply solution: flowmeter, flow meter for 24 v external power supply or batteries.

(3) : preamplifier output frequency.Replaceable preamplifier.

(4) : motherboard damage.Replaceable flowmeter motherboard.

2 meter, flowmeter, according to the temperature, transient flow with pressure and the actual work instructions

(1) : if the pressure value is indicated "80" or meter "maximum pressure" (upper limit within the flowmeter selection reference table) can be.Reasons: one is the external new pressure sensor, watching to see if the header according to the local atmospheric pressure, if according to the local atmospheric pressure, the damage of the original sensor.Can replace the pressure sensor.Second, external half new pressure sensor, if the header display is still the "80", the flowmeter motherboard bad.Replaceable flowmeter motherboard.

(2) : the pressure value for a certain value (header field work pressure change is bigger, flowmeter showed no changes or smaller pressure).Reasons: one is the pressure sensor hole blockage.Can take pressure hole cleaning.Secondly, the pressure sensor linear calibration curve becomes bad.Replaceable or to set pressure sensors.

3, the header display instantaneous flow rate and pressure is normal, temperature display and temperature field

(1) : temperature values for "- 75 - c" or more than 100 ℃.Reason: the temperature sensor is damaged.Replaceable sensor.

(2) : temperature exceeds or is lower than the actual temperature value, replace the sensor, still for the phenomenon.Reason: the damage of thermal pressure circuit.Replaceable thermal pressure circuit.

4, flowmeter no display meter

Reasons: (1) meter without 24 v power supply or batteries.To 24 v battery power supply or replace the flowmeter flowmeter.

(2) : flowmeter damage of LCD panels.Replace the flowmeter LCD panels.

(3) : flowmeter motherboard damage.Replace the flowmeter motherboard.

(4) : power supply connection bolt or mistake.Find and rewiring.

Nine, install and use notice:

1, choose reasonable installation place.The installation site should avoid strong electric power equipment, high frequency equipment, strong power switch;Avoid high temperature heat source and radiation of heat;Avoid high temperature and strong corrosive atmosphere influence: avoid strong vibration and installation, wiring, and easy maintenance.In the upstream and downstream sensors, must eliminate the long pipeline vibration generated by moving.

2, general requirement level installation, by the flow of current body should be consistent with refers to the flow arrow on the shell.Can be installed vertical or inclined.When liquid, should ensure that the sensor is completely filled with liquid.In order to does not affect the normal fluid loss, maintenance Suggestions in the installation of the instrument and add bypass.

3, low requirement for straight pipe before and after, in principle don't need a straight pipe before and after the flowmeter is allowed, but general requirements before the instrument has 3 d length of straight pipe, instrument after 1 d length of straight pipe.Special circumstances require 5 d and 3 d length.When a single or double bend bend pipe bending radius is greater than 1.8 D, flowmeter can don't straight pipe before and after.Under the condition of various pipe installation required for straight pipe length.

Falling in to 4, measuring gas or steam can be used when the degree of pressure compensation, the installation position of thermometer and pressure gauge.

5, when the current body contains impurities, should be put in front of the instrument already device or filter, but still should guarantee the straight pipe in front of the instrument.

6, measuring a small amount of heterogeneous gas liquid two phase flow sensor installation method.Measuring liquid, there may be a small amount of gas phase in the pipeline, its content does not exceed the prescribed gas liquid two phase fluid, so as to prevent gas stranded inside the sensor, you must install gas separator.Measuring gas when the pipe was measured condensate gas may be produced, and gas exist in unstable liquid phase was not removed, in order to prevent fluid retention, vertical installation within the sensor.Fluid when measuring high and low temperature sensor itself should be effective guarantee measures.

7, instrument measured by measuring the volume of a gas flow for the actual flow of the gas being measured work condition.If the actual flow conversion into standard state of flow, can press type calculation type, 4?P is a standard volume flow conditions;4, it is the working status of the volume flow amount;Ho is the absolute pressure of the gas being measured standard condition;To the thermodynamic temperature of the gas being measured is a standard condition;The household is work state, the absolute pressure of the gas being measured;T is the working status the thermodynamic temperature of the gas being measured;Z is the compressibility of the gas being measured work condition.

8, when the pipeline is longer, vibration may occur when the fixed bracket should be installed at upstream and downstream flow meter, prevent the pipeline vibration.According to the experience, the flow measurement value vulnerable to air flow pulsation and pressure changes.

9, volume flow meter coefficient Kvn and mass flow meter coefficient K, z o is established in the state of normal temperature calibration instrument before they leave the factory.Instrument working status and laboratory calibration status is large, the instrument coefficient K, and K 'correction should be done on the instrument coefficient correction method is the same as the vortex flowmeter.

Ten, flange connection size:

Eleven, selection of coding:

Twelve, designing order selection guidelines:

1, instrument selection, as far as possible not to use the work flow in the lower limit value, so the meter diameter should be as small as possible, in order to obtain a larger flow rate and flow range.

2, the flowmeter should be used in the technical parameters of medium pressure and temperature range.Don't deliberately choose the high pressure level and ultra-high temperature instrument, should be selected according to the actual work pressure and temperature instruments, which had higher prices.

3, in the explosive dangerous location, should choose explosion-proof type flowmeter.

4, the lower limit of flowmeter flow depends on the operation condition of the medium density and kinematic viscosity, the maximum flow is generally not affected by medium pressure and temperature, so to determine the flow range as long as you determine the actual minimum flow can be available.Calculate the minimum flow rate, flow range check table to determine the appropriate diameter.

After-sales service commitment:

1, our company sold by flow meter series products within twelve months appear quality problem, is responsible for free maintenance.

2, the warranty period, any quality problems such as the products of our company, my company is responsible for free repair or replacement.

3, the warranty period, such as user improper use, damaged products, my company is responsible for the maintenance, charge damage parts cost.

4, after the warranty period appear quality problem, my company is responsible for the maintenance, charge damage parts cost.

5, such as user need to my company site services, to users in the province I company service personnel to reach the site within 12 hours, fujian association of foreign languages and user reach the site within 48 hours.