KH-LGB seriesBlast furnace gas flowmeterIt is mainly used for flow measurement of industrial pipeline media fluids, such as gases, liquids, steam, and other media. Its characteristics are small pressure loss, large range, high accuracy, and almost unaffected by parameters such as liquid density, pressure, and temperature when measuring volumetric flow rate under working conditions. No movable mechanical parts, therefore high reliability and low maintenance. The instrument parameters can remain stable for a long time.
The major advantage of KH-LGB intelligent vortex flowmeter is its excellent anti vibration performance, no zero drift, and high reliability.
Through extensive waveform and frequency analysis of the vortex flowmeter over a long period of time, Kehao has designed an optimal probe shape, wall thickness, height, probe rod diameter, and matching piezoelectric crystal. Advanced CNC lathes are used for processing to ensure the technical parameters of coaxiality and smoothness, and special processing techniques are used to overcome the common problem of the inherent self oscillation frequency of the vortex flowmeter affecting the signal to the greatest extent possible. This is the technological advantage of Kehao Company in producing vortex flowmeters, which enables the vortex flowmeters produced by Kehao Company to have good anti vibration capabilities.DN50 blast furnace gas flowmeter/vortex flowmeter directly supplied by the manufacturer
② The sensor of the LGB series intelligent vortex flowmeter has strong universality, which makes the sensor have good interchangeability. Advanced CNC equipment is used to process the sensor body and vortex generator to ensure processing accuracy, thereby making the components (especially the vortex generator) highly versatile and truly ensuring that the repeatability and accuracy of the sensor will not be affected by component replacement; Capable of generating strong and stable vortex signals.
③ The structure is simple and sturdy, with no movable parts, high reliability, and easy to use and maintain.
④ The detection component does not come into contact with the medium, with stable performance and long service life
The sensor adopts a detection probe installed separately from the vortex generator, and a high-temperature resistant piezoelectric crystal is sealed inside the detection probe, which does not come into contact with the measured medium. Therefore, the FFM63 series vortex flowmeter has the characteristics of simple structure, good universality, and high stability.
⑤ Output pulse signals or analog signals proportional to the flow rate, without zero drift, high accuracy, and convenient networking with computers
⑥ Wide measurement range, with a range ratio of up to 1:10DN50 blast furnace gas flowmeter/vortex flowmeter directly supplied by the manufacturer
⑦ When measuring volumetric flow rate with a vortex flowmeter, no compensation is required. The signal output by the vortex flowmeter is actually linearly related to the flow rate, that is, directly proportional to the volumetric flow rate. The purpose of pressure and temperature compensation is to obtain the density of the fluid, which is multiplied by the volumetric flow rate to obtain the mass flow rate. If measuring the volumetric flow rate of a gas, compensation is not required.
⑧ Low pressure loss.
Using a DN50 vortex flowmeter to measure the flow rate of combustible gases, if the large flow rate Qmax in the pipeline is 200m3/h, the pressure loss of the sensor is: △ P=1.08 × 10-6 ρ v2 (kPa)=0.605 KPa
⑨ Within a certain Reynolds number range, the flow characteristics are not affected by fluid pressure, temperature, viscosity, density, or composition, but only by the shape and size of the vortex generator.
⑩ Widely applicable, capable of measuring the flow rates of steam, gas, and liquid.
KH-LGB seriesBlast furnace gas flowmeterTechnical parameters
Measure fluids: saturated steam, superheated steam, gas, liquid (avoid multiphase flow)
Measurement accuracy and repeatability:

● Measurement range

Rated pressure: 1.6MPa, 2.5MPa, 6.3MPa
Fluid temperature: -40 ℃~250 ℃ (ordinary type), 100 ℃~350 ℃ (ordinary type)
● Structural type: Integrated vortex flowmeter
● Structural material

● Working power supply

● Output signal: pulse output, 4-20mA current output, RS485 communication, and three other outputs to choose from
● Electrical interface: M20*1.5
● Protection level: IP65
● Body processing: The sensor body is made of stainless steel sandblasted, and the amplifier housing is sprayed with plastic.
● Environmental temperature: -35 ℃~60 ℃ (without LCD), -5 ℃~60 ℃ (with LCD)
Relative humidity: 5% to 95 ℃
KH-LGB seriesBlast furnace gas flowmeterInstallation requirements
There are many structural forms of vortex flow meters, and installation and maintenance personnel need to understand the specific structure, characteristics, and conversion of flow signals of the installed instruments, understand the various links in the signal transmission process, and install according to the product manual to ensure accurate measurement of the flow meter.
1. Reasonably choose the installation site and environment
Avoid strong electrical equipment, high-frequency equipment, and strong power switch devices; Avoid the influence of high temperature heat sources and radiation sources, avoid strong vibration areas and corrosive environments, and consider easy installation and maintenance.
2. There must be sufficient straight pipe sections upstream and downstream
If the upstream of the sensor installation point is greater than or equal to 15. For tapered pipes, the upstream straight pipe section is ≥ 15D, and the downstream straight pipe section is ≥ 5D

If the upstream of the sensor installation point is greater than or equal to 15. Gradual expansion pipe, then: upstream straight pipe section ≥ 18D, downstream straight pipe section ≥ 5D

If there is 90 upstream of the sensor installation point. For elbows or T-shaped joints, the upstream straight pipe section should be ≥ 20D, and the downstream straight pipe section should be ≥ 5D

If there are two 90 points upstream of the sensor installation point on the same plane. Bend, then: upstream straight pipe section ≥ 25D, downstream straight pipe section ≥ 5D

If there are two 90 points upstream of the sensor installation point on different planes. Bend, then: upstream straight pipe section ≥ 40D, downstream straight pipe section ≥ 5D
The regulating valve should be installed 5D downstream of the sensor. If it must be installed upstream of the sensor, the upstream straight pipe section of the sensor should not be less than 50D, and the downstream should not be less than 5D.

3The piping upstream and downstream of the installation point should be concentric with the sensor, and the coaxial deviation should not be less than 0.5DN
The inner diameter of the upstream and downstream piping of the sensor installation point should be the same as the sensor diameter, and it should meet the requirements of the following formula:
0.98DN≤D≤1.05DN
In the formula: DN - sensor diameter;
D - Inner diameter of piping.
The sealing gasket between the sensor and the flange cannot protrude into the pipeline, and its inner diameter can be slightly larger than the sensor diameter.
4Pipeline adopts vibration reduction measures
Sensors should be avoided as much as possible from being installed on pipelines with strong vibrations, especially lateral vibrations. If installation is necessary, vibration reduction measures must be taken by installing pipeline fastening devices and adding anti vibration pads at the upstream and downstream 2D positions of the sensor.

Installing on a horizontal pipeline is a common installation method for flow sensors.
When measuring gas flow, if the measured gas contains a small amount of liquid, the sensor should be installed at a higher position in the pipeline.


When measuring liquid flow rate, if the measured liquid contains a small amount of gas, the sensor should be installed at a lower part of the pipeline.

6Installation of sensors in vertical pipelines
When measuring gas flow, the sensor can be installed on a vertical pipeline with no restrictions on the flow direction. If the tested gas contains a small amount of liquid, the gas flow should be from bottom to top.
When measuring liquid flow rate, the liquid flow direction should be from bottom to top: this will not add additional liquid weight to the probe.


7Sensors are installed on the side of horizontal pipelines
Regardless of the type of fluid being measured, sensors can be installed on the upper side of horizontal pipelines, especially for measuring superheated steam, saturated steam, and low-temperature liquids. If conditions permit, side installation can be used to minimize the impact of fluid temperature on the amplifier.

8Inverted sensor in horizontal pipeline
This installation method is generally not recommended. This installation method is not suitable for measuring general gases and superheated steam. Can be used to measure saturated steam, suitable for measuring high-temperature liquids or situations that require frequent pipeline cleaning.

9Installation of sensors on insulated pipelines
When measuring high-temperature steam, the insulation layer should not exceed one-third of the height of the support.

10Selection of pressure and temperature measurement points
According to the measurement requirements, when measuring pressure and temperature near the sensor, the pressure measuring point should be 3-5D downstream of the sensor, and the temperature measuring point should be 6-8D downstream of the sensor.

Correct wiring of vortex flowmeter
General principle: Use shielded cables in places that are susceptible to electrical noise interference. The shielding layer should be reliably connected to the grounding screw of the amplifier or to the working grounding in the control room. When working in high or low temperature environments or when the on-site air contains oil, solvents, or other corrosive gases, shielded cables suitable for such special situations should be used.
Wiring for frequency signal output
The flowmeter that outputs frequency signals is transmitted to other devices using a three wire system, with a power supply of 24VDC ± 10% (or 12VDC). The small load resistance of the output circuit is 10K Ω, and the large capacitor is 0.2UF.

4-20mAWiring for signal output
The vortex flowmeter that outputs 4-20mA signals is transmitted to other devices using a two-wire system, with a power supply of 24VDC ± 10% and a high load resistance of 600 Ω in the output circuit. (including the resistance of the cable)

Structure types and external dimensions data table of vortex flowmeter