Installation specifications and test results of sulfuric acid flow meter

Installation specifications and test results of sulfuric acid flow meter

The principle of hydrochloric acid flowmeter measurement is based on Faraday's law of electromagnetic induction. The measuring tube of the flow meter is a non-magnetic alloy short tube lined with insulating material. The two electrodes are fixed to the measuring tube through the tube wall in the diameter direction. The electrode tip is substantially flush with the inner surface of the liner. When the exciting coil is excited by the bidirectional square wave pulse, an operating magnetic field having a magnetic flux density B is generated in a direction perpendicular to the axis of the measuring tube. At this time, if a fluid having a certain conductivity flows through the measuring tube, the cutting magnetic line induces the electromotive force E. The electromotive force E is proportional to the product of the magnetic flux density B, the inner diameter d of the measuring tube and the average flow velocity V, and the electromotive force E (flow rate signal) is detected by the electrode and sent to the converter through the cable. After the converter amplifies the flow signal, it can display the fluid flow, and can output pulses, simulate current and other signals for flow control and regulation.

What kind of attention should be paid to the selection of hydrochloric acid flowmeter?
1, the display mode of the meter: generally divided into one-piece display and split display.
2. The diameter of the pipe installed in the instrument.
3. What is the measured medium? Is it corrosive? Is it conductive? What is the temperature and pressure?
4, the flow range of the medium, small to, if the need for higher precision, you need to provide common traffic.
5, the choice of signal source: generally have 4-20mA, 485 communication, voltage signal and so on.
6, connection: flange, thread and clamp.
7. Selection of lining: The customer can select the corresponding lining material according to the measured properties of the medium.
Polytetrafluoroethylene (F4): It is resistant to boiling hydrochloric acid, sulfuric acid, nitric acid and aqua regia. It is also resistant to concentrated alkali and various organic solvents. Not resistant to chlorine trifluoride, high temperature chlorine trifluoride, high flow rate liquid fluorine, liquid oxygen, self-oxygen corrosion.
Polytetrafluoroethylene propylene (F46): same as F4, wear resistance, negative pressure resistance is higher than F4
Polyfluoroethylene (Fs): The upper temperature limit is lower than that of polytetrafluoroethylene, but the cost is also low.

Polychloroprene:
 1, has excellent elasticity, high tearing force, good wear resistance. 2, resistant to general low concentration acid, alkali, salt medium corrosion, not resistant to oxidation medium corrosion.
Polyurethane rubber: 1, wear resistance is extremely strong. 2. Poor corrosion resistance.
8. Selection of electrodes: Select the appropriate electrode material according to the chemical properties of the medium to be tested.
Stainless steel 316L: It is used for industrial water, domestic water, sewage and other weak corrosive media. It is suitable for petroleum, chemical, steel and other industrial sectors as well as municipal, environmental protection and other fields.
Hastelloy B: has good corrosion resistance to hydrochloric acid at all concentrations below the boiling point, and is also resistant to corrosion by non-chlorinated acids, bases, and non-oxidizing salts such as sulfuric acid, phosphoric acid, hydrogen fu acid, and organic acids.
Hastelloy C: resistant to non-oxidizing acids, such as nitric acid, mixed acid, or corrosion of mixed media of chromic acid and sulfuric acid, and also resistant to oxidizing salts such as Fe, ",," under Cu or other oxidants. Such as hypochlorite solution above sea temperature, corrosion of seawater
Titanium: It is resistant to seawater, various chlorides and hypochlorites, oxidizing acids (including fuming sulfuric acid), organic acids and alkalis. It is not resistant to the corrosion of relatively pure reducing acids (such as sulfuric acid or hydrochloric acid), but if the acid contains an oxidizing agent (such as nitric acid, Fc++, Cu++), the corrosion is greatly reduced.
Tantalum: It has excellent corrosion resistance and glass is very similar. In addition to hydrogen fu acid, fuming sulfuric acid, alkali, it is almost resistant to corrosion by cutting chemical media (including boiling point hydrochloric acid, nitric acid and sulfuric acid below 50 ° C). Antimony in alkali; corrosion resistant.
Platinum/titanium alloy: Almost resistant - cut chemical media, but not for aqua regia and ammonium salts.
Stainless steel coated tungsten carbide: for non-corrosive, strong abrasive media.

To sum up briefly: the correct selection can only play the performance of the hydrochloric acid flowmeter. If the selection is wrong due to inaccurate parameters, the measurement of the on-site condition is inaccurate, and the data fluctuation is large and unstable. Serious can directly affect the service life of the product.

Installation specifications and test results of sulfuric acid flow meter
In response to the needs of our customers, today's Xiaobian will explain the installation specifications of the sulfuric acid flow meter. With the continuous development of industrial automation control, the use of sulfuric acid flow meters has become more and more extensive. Many customers are not sure how much the installation regulations will affect the products. Let's look at the installation:
1, ensure full pipe installation
Make sure that the flow sensor is full of the fluid under test when measuring, and that the non-full tube state cannot occur. If the pipe is not full or the outlet is vented, the sensor should be mounted on a siphon.
2, horizontal and vertical installation
The sensor can be mounted horizontally and vertically, but it should be ensured that the effects of deposits and bubbles on the measuring electrode are avoided and the axial orientation of the electrode is kept good. When installed vertically, the fluid should flow from bottom to top.
3. Installation between elbows, valves and pumps
To ensure the stability of the measurement, a straight pipe section should be placed before and after the sensor. If this is not possible, a stabilizer should be used or the cross-sectional area of ​​the measuring point should be reduced.
4, the sensor can not be installed in the pump inlet
To avoid negative pressure, the sensor should not be installed in the pump's water inlet, but should be installed in the pump's water outlet.
5, the inlet of the sensor straight pipe section and the outlet straight pipe section
For an ideal installation location, there should be enough straight pipe sections before and after the measurement point. The inlet straight pipe section should be ≥5D, and the outlet straight pipe section should be ≥3D (D is the sensor nominal diameter).
The plug-in inlet straight pipe section should be ≥ 20 D and the outlet straight pipe section ≥ 7D (D is the nominal diameter of the sensor).
In general, the accuracy of a sulphuric acid flow meter measurement, in addition to the quality of the product itself, depends more on its installation, so you must read the instruction manual carefully before installing the product.

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