Hehua brand low temperature mass flowmete

  The patented product hh-cmf low temperature mass flowmeter independently developed by the company is an advanced high-precision mass flow measurement instrument
Due to its excellent performance, it has high measurement accuracy, good repeatability, low requirements for fluid state and small pressure loss
The multi-functional hh-cmf low temperature mass flowmeter can directly measure the mass flow, volume flow, density and temperature of liquid or slurry without manual calculation or estimation, so that users can more directly understand the operation process of fluid Excellent performance even in harsh working environment
There are no moving parts inside, there is no need for complex installation, and there are no harsh requirements for working conditions
Each sensor is made of stainless steel, and the various outputs of the transmitter can meet your various needs 1
Working principle When the mass of the particle is m, the velocity is & upsilon; When making angular velocity of P-axis & omega; When moving in a rotating pipe, the particle is subjected to the acceleration and force of two components
a
Normal acceleration is centripetal force acceleration & alpha; r
Its magnitude is equal to & omega; 2R, facing the P-axis; b
Tangential acceleration & alpha; T is the Coriolis acceleration, which is equal to 2-Omega& upsilon;， Direction and & alpha; R vertical
Due to compound motion, in the & alpha; Coriolis FC = 2 & Omega in t direction& upsilon; m
The pipe exerts a reverse force on the particle - FC = - 2 & omega& upsilon; m。 When the density is & Rho; The fluid in the rotating pipe at a constant speed & upsilon; When flowing, any length & Delta; All pipes of X will be subject to a & Delta; Tangential Coriolis force of FC
Where a & mdash& mdash; The internal cross-sectional area of the pipeline
Since the flow of mass flowmeter is & Delta; m，δ m=ρ& upsilon; A
Therefore, the mass flow can be measured by directly or indirectly measuring the Coriolis force generated by the fluid flowing in the rotating pipe, which is the basic principle of the low-temperature mass flowmeter However, it is difficult to generate Coriolis force through rotational motion
At present, products are replaced by pipeline vibration, that is, the thin-walled measuring tube fixed at two broken ends is excited by the resonance or near resonance frequency of the measuring tube at the midpoint, and the fluid flowing in the tube generates Coriolis force, causing the front and rear halves of the measuring tube to deflect in the opposite direction, The deflection is detected by electromagnetic method to obtain the mass flow Because the fluid density will affect the vibration frequency of the measuring pipe, and the density has a fixed relationship with the frequency, the mass flowmeter can also measure the fluid density 2
Product features & bull Direct measurement of mass flow has high measurement accuracy& bull; A wide range of fluids can be measured, including various liquids of high viscosity liquid, slurry containing solids, liquid containing trace gas and medium and high pressure gas with sufficient density& bull; The vibration amplitude of the measuring pipe is small and can be regarded as non moving parts
There are no obstructions and moving parts in the measuring pipe& bull; It is not sensitive to the upstream velocity distribution, so there is no requirement for upstream and downstream straight pipe sections& bull; The measured value is not sensitive to fluid viscosity, and the change of fluid density has little effect on the measured value& bull; It can be used for multi parameter measurement, such as density measurement in the same period, and the concentration of solute in the measurement solution is derived from this 3
Main technical parameters , Tested media Liquid, gas Measure diameter 1mm~200mm  Measurement items Mass flow, density, temperature, volume flow,% concentration Density measurement range 0
2g/cm3~3
5g/cm3  Density measurement accuracy ,& plusmn; 0
002g/cm3  Temperature measurement range ,- 200℃～+300℃  Temperature measurement accuracy ,& plusmn; 1℃  Medium temperature ,- 200℃～+250℃  Flow measurement error Liquid 0
2% R + CZ, 0
15% R + CZ, gas 0
5% R + CZ, 1
0% R + CZ, Signal output Current 4 ~ 20mA, pulse O ~ 2KHz, RS485 communication, HART Communication Power supply External supply 24VDC The measuring tube material 304316 can also be negotiated and provided according to the user's requirements Explosion proof grade ExibIICT4，ExdIICT4  Enclosure protection grade IP67  4
Installation of flowmeter A
General requirements for installation of flow sensor , Due to the differences in the shape and structural design of the measuring pipe, the installation requirements are also very different
Therefore, the installation methods and avoid prohibitions specified by our factory must be followed
For example, some models of flow sensors can be directly connected to the pipe, while some models require a support frame or foundation
In order to isolate the influence of pipeline vibration on the instrument, sometimes the sensor and pipeline should be connected by flexible pipe, and there should be a section of rigid straight pipe with supports respectively fixed between the flexible pipe and the sensor
Before purchasing, you should ask for the installation and operation instructions from our company for reference, comparison and selection The installation design shall make it have a long service life as far as possible
In order to remove the solids and gas inclusions that cause premature wear and measurement errors, protective devices such as filter or gas separation shall be installed upstream of the sensor according to the fluid and pipeline conditions
, If you want to calibrate the instrument online on site, you should consider the drainage connection port and valve, as well as the corresponding space
B, * the installation posture and flow sensor of the flow sensor will measure the residual solids, fouling and retention gas in the tube, which will affect the measurement accuracy
Generally speaking, it is ideal to install in a vertical pipe flowing from bottom to top; However, for non-linear measuring tubes, the mass flowmeter is installed on vertical or horizontal tubes
It depends on the vibration condition of the pipeline and the application conditions
The installation position must make the measuring pipe full of liquid
For example, the fluid on the horizontal pipe flows through the mass flowmeter and is directly put into the container without back pressure
The measuring pipe is often not full, which will cause fierce fluctuation of the output signal
C
Installation of stop valve and control valve , In order to ensure no flow during zero adjustment, stop valves shall be set at the upstream and downstream of the mass flowmeter and there shall be no leakage
The control valve shall be installed at the downstream of the mass flowmeter to control the mass flow