Vortex flowmeter selection
(1) Selection of vortex flow transmitter
In the measurement of saturated steam, VA type piezoelectric vortex flow transmitter is adopted. Because of the wide range of vortex flowmeter, in practical applications, it is generally considered that the flow of measuring saturated steam should not be lower than that of vortex flowmeter. The lower limit, that is to say, the fluid flow rate must not be less than 5 m/s. According to the size of the steam, the vortex flow transmitters with different calibers are selected, and the caliber of the transmitter cannot be selected by the existing process pipe diameter.
(2) Selection of pressure compensation pressure transmitter
Since the saturated steam line is long and the pressure fluctuates greatly, pressure compensation must be adopted. Considering the corresponding relationship of pressure, temperature and density, only pressure compensation can be used in the measurement, because the saturated steam pressure of Mingtong Company is 0.3-0.7MPa. Range, the range of pressure transmitter can be selected 1MPa.
(3) Display instrument selection
Display instrument intelligent flow display instrument with voltage regulation compensation, instantaneous flow display and cumulative flow accumulation function.
Flowmeter product features:
Using intelligent judgment, the measurement correction setting is not used, and the air traffic control alarm and electrode detection application are more convenient;
Advanced "rough error handling" technology, which can remove fluids such as slurry to measure sharp disturbances, reduce output runout, maintain high precision measurement and make output more stable;
With a fluid density setting, it can display mass flow;
Constant current excitation current range, 125mA, 250mA optional, can be used with different manufacturers, different types of electromagnetic flow sensors;
Control function with remote reset of the totalizer, with contact signal input for starting and stopping accumulation, suitable for total inspection and batch processing applications;
With self-test and self-diagnosis function;
Advanced non-volatile memory for higher circuit reliability and effective protection of setup and measurement parameters;
The meter can be equipped with an unpowered clock and memory for recording the power down time, power-on time and power-down time;
The meter has an optional hour recording function that can store flow and electrode resistance measurements for more than 30 days.
The new keyboard processing method avoids the keyboard operation affecting the measurement, and can enter and return the operation menu to make the parameter setting more convenient;
The total display uses 10-bit decimal 9999999999 full-value carry, which solves the practice of double-word full value 4294967285 (hexadecimal FFFF) carry-in habit;
With wireless transmission, the mesh network is organized by the wireless HART protocol.
In the case of small flow metering, the film surface ratio is the largest, the Roots flowmeter is second, and the turbine flowmeter is the smallest. The initial flow performance of the volumetric flowmeter should be superior to the velocity flowmeter. For industrial and commercial users with large total gas consumption and low heat load for each gas, the volumetric flowmeter, ie, the membrane meter and the Roots flowmeter, should be preferred to meet the flowmeter requirements of a single burner when used alone. It can also meet the measurement requirements of the maximum flow rate when all burners are used at the same time.
Not all industrial and commercial users can solve the measurement problem by selecting a volumetric flowmeter with a larger range. The volumetric ratio of the volumetric flowmeter is limited, and it is impossible to increase without limit. The selection of the flowmeter cannot be solved. This kind of user has a measurement problem. When the user only uses a single device for gas, or when operating at low flow rate, the initial flow rate and minimum flow rate of a single flow meter may not meet the minimum flow rate requirement. A single large flow meter cannot measure low gas consumption, which will result in Large supply and marketing differences.