Coriolis mass flowmeters measure gases and liquids somewhat differently.The article mainly focuses on some precautions for the flowmeter used to measure the hydrogen flow on the hydrogenation kettle, mainly considering the accuracy and safety of the Coriolis mass flowmeter. The following are the relevant items that need to be noted during the installation process.

The first,pay attention to the installation direction

Coriolis mass flowmeter sensor has three installation methods: downward, upward and flag. When measuring gas, it is recommended to install the measurement tube upward to prevent liquid from accumulating in the measurement tube of the sensor. If there is liquid in the measuring tube, gas-liquid mixing will occur, resulting in the flowmeter not working.

Secondly,the range of the flowmeter needs attention

When measuring gas, the Coriolis flowmeter has a different range than when measuring liquid. Generally, the manufacturer's label indicates the range of measuring liquid. For example, the flow range of the Zhonglong mass flowmeter selected this time is 80-800 kg/h, which is the range of the liquid. Overall, the gas range is generally one fifth of the liquid, and the measurement range is one fifth of the lower limit of the liquid to one tenth of the upper limit of the liquid, which is 16-80 kg/h.

Also note that the density of the gas

At normal temperature and pressure, hydrogen is a gas that is extremely flammable, colorless, transparent, odorless, tasteless, and difficult to dissolve in water. Hydrogen is a gas with a relatively low density known in the world. The density of hydrogen is only 1/14 of that of air. That is, hydrogen is at 1 standard atmospheric pressure and 0 ° C. The density of hydrogen is 0.089 g/L. Hydrogen is relatively small in molecular weight. substance.

The gas is compressible, the operating pressure is 1.2 MPa, and the operating temperature is 26 degrees Celsius. The DN15 mass flowmeter was selected according to the flow rate, and it was later found on the scene that it should be the standard flow rate. The density difference between the working condition and the standard condition is more than ten times, and later changed the DN15 to DN6.

At last,threshold flow setting

Because of the instability of the gas, a small flow rate may appear when measuring the gas flow rate. Coriolis mass flow meters of various brands have the function of cutting off the small flow rate. Generally, the setting range of the threshold flow rate is 1% to 3% of the measuring range, it is recommended to start with a smaller setting. When setting, it is necessary to pay attention to that the unit can not be mistaken. If the unit is mistaken, the meter will not display the flow rate.