The inspection rod shall be fixed on the pipeline according to the connection head. After tightening the connection head, the inspection rod shall not be loosened or leaked. Pipeline vibration and hydrodynamics impact will make the fixed head of ultrasonic flowmeter loose and take off, resulting in the fracture of inspection rod, damage measurement and property loss.

The total pressure hole of the inspection rod controller must be straight to the inflow, and the error shall not exceed 7 °. The inspection rod shall be inserted exactly along the diameter direction of the pipe. For vertical pipes, the inspection rod can be installed on all parts 360 ° along the pipe circle on the pipe plane. The high and low impulse pipes shall be on the same plan; for the level pipes, they shall be installed at a skew downward side during measurement. Whether the flowmeter can be measured and the length of its service life are directly related to whether it is properly installed. Once the flowmeter is installed, the system deviation that endangers the accuracy of the flowmeter will immediately follow from the beginning to the end, which can not be removed from the mobile software. The proper installation method can refer to the installation standard of differential pressure flowmeter, which is not explained here.

Mass flowmeter (also known as fluted uniform tube flowmeter and Toba tube flowmeter) belongs to differential pressure flowmeter. Application: exhaust air volume, water, steam, liquefied gas, soot, CO2, N2, radon and other substances * * measurement. Precision: ± 1% FS, ± 0.5% FS. The length of 7d-9d straight pipe must be ensured in the front pipe of the inspection rod controller (this data information is provided by different manufacturers, from 3D to 30d). Only in this way can the water flow of the liquid and gas (vapor) body in the large pipe be distributed in the center line as symmetrically as possible. Only in that way can the total flow through all cross sections be measured by measuring the water flow in several aspects. Otherwise, the water flow of liquid and gas (steam) bodies in large pipes may be very complicated, and the fluctuation of flow coefficient K may be quite large, which can not ensure the measurement degree. However, it is unlikely to ensure a long straight pipe in the specific process technology. The small editor thinks that if the Annubar flowmeter of a certain type is clearly adopted, he can discuss with the supplier to reduce the straight pipe as much as possible under the premise of ensuring the repeatability. The description of relevant materials shows that if the ratio between the diameter of the measuring pipe and the diameter of the processing process pipe is less than 1 / 10, the length of the straight pipe of the front side pipe can be reduced to three to four days

1、 Key characteristics of pitot tube flowmeter

The turbine flowmeter is suitable for measuring the water flow of steam, liquid, gas, liquefied gas and other substances, especially in the wind force measurement of the appropriate large-diameter ventilation duct. It determines the total flow based on the measurement of the wind force of the duct and the cyclone speed in the smoke exhaust duct of the furnace and kiln through calculation. It is widely used in scientific research, production and manufacturing, classroom teaching, ecological environment protection and its clean room, natural ventilation of coal mine, project management unit. It has the characteristics of reliable basic principle, simple structure, low cost and so on. It is an ideal flow detection supporting facility instrument panel for online monitoring and control system software of industrial production boiler gas emission. Pitot tube, which is called pitot tube in English, is a tube-shaped device for measuring the total pressure and negative pressure of the vapor to determine the cyclone speed, At the initial stage, the key is to measure the speed of the aircraft. Based on this, the hq-ptg series product pitot tube flowmeter designed by five star red flag company is a measuring equipment which calculates the speed of the steam body and multiplies the section to calculate the total flow according to the working pressure at the measuring sampling point and the Bertin's law.

2、 Composition of pitot tube flowmeter

The pitot tube is generally composed of primary current blocking components (controllers), intelligent transmitters and valves. In special cases, it is also equipped with gate valves, online plug-in and offline equipment, purge valves, etc.

3、 Principle of pitot tube flowmeter

The pitot tube flowmeter is composed of a small metal tube with a plate structure and a bending angle. At the top, there is a rated power hole of the motor facing the current, and a negative pressure hole around the outer wall. Insert the controller into the center of the pipeline. The total pressure hole points to the upstream and downstream of the hydrodynamics. The difference between the total pressure and the negative pressure is the evaluation gas pressure in the center of the pipeline. The two sides of the differential pressure transmitter are respectively connected with the main pressure pipe Connect with the negative pressure pipe, evaluate the data information fitting curve according to the five grid mathematical entity model, obtain the matched total flow value, and convert the matched total flow data signal into the standard 4 ~ 50mA data signal according to the differential pressure transmitter.

4、 Key characteristics of pitot tube flowmeter

1. Be able to measure various substances

It is suitable for measuring the pipe speed of steam, liquid, gas, liquefied gas and other substances, especially for the wind measurement of large-diameter ventilation duct. It has the characteristics of reliable basic principle, simple structure, low cost and so on. It is an ideal flow detection instrument panel for the online monitoring system software of industrial production boiler gas emission.

2. Optional on-line installation, plug-in, cleaning and blowback equipment

For some measuring points that cannot be shut down for installation, online installation can be carried out without shut-down by using on-line plug-in equipment; for substances containing too much residue or stains, in order to avoid blocking of pressure tapping hole, online plug-in equipment can also be used for timely removal or online reverse blowing equipment can be used for reverse blowing to ensure long-term reliability of measurement.

3. Central pressure tapping, substantial blockage removal

The controller is located in the center of the pipeline to take pressure and discharge the blockage substantially. The fully automatic ash removal on the maintenance line equipped with the ash removal rod is optional. The actual effect of the blockage discharge is better.

4. Low installation cost, maintenance free foundation

Plug in installation method, simple installation, plus the unique wear-resistant coating on the top of the controller, the appearance of the controller can always remain unchanged, so the long-term reliability is good.