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Thermal gas mass flow meter Description:

HNHF-8000 thermal gas mass flow meter based on the principle of thermal diffusion mass flow gas detection, has high accuracy, range ratio features. Integrated in explosion-proof transmitter housing in a series of intelligent chip, meter stable, easy to operate. There are two installation forms, one is applied to large diameter pipe installation in the form of plug-in probes, one for flow-through chamber is installed in the form of small-diameter pipes, which makes HNHF-8000 series of thermal gas mass flow meter able to meet most field applications. Widely used in electricity and gas ﹑ water monitoring, oil and gas industry, power industry, chemical industry, metallurgical industry, pulp and paper industry, food and pharmaceutical industry, environmental protection, other industries

HNHF-8000 thermal gas mass flow meter

Sensor principle

HNHF-8000 series gas mass flow meter is based on the Guinness Book of Law (thermal diffusion theory) of the instrument. Kim's Law: fluid molecules flowing through the heat source and how much heat loss is proportional to the number. The instrument's sensor has two sensors, one for both a heat source and do sensors, one to measure only the medium temperature, fluid flow, the flow of fluid through both the sensor and the heat source of the number of molecules have a proportional amount of heat loss relationship, so we can calculate the electronic module to fluid flow. Because it measures the quality of the fluid molecules, and thus independent of the medium temperature and pressure, flow measurement is mass flow.
Produced by thermal diffusion theory meter has two design methods: First: Based on the principle of constant temperature difference; the second is based on the principle of constant power.
: Common Data Model
P / △ T = A + B (Q) N.
among them:
P --- power dissipation,
△ T --- the temperature difference between the two sensors,
Q --- mass flow rate, N --- index coefficient,
A, B and thermal properties of the gas is related to the coefficients.

CTD principle: △ T remains unchanged, the power dissipation P and the fluid flow rate Q as a function of increasing exponential relationship.
Constant power principle: constant power dissipation, flow and temperature difference △ T fluid Q decreasing exponential function relationship.
My company mainly produces thermal gas mass flow meter based on the principle of constant temperature difference.

Features
 
  - Coefficient of different gases settings
  - The use of patented technology high stability platinum RTD sensor
  - Display zero clearing
  - Analog output correction
  - Multi-point non-linear curve correction
  - Wide range ratio of 1000: 1, Cheng Lingmin low volume, pressure loss can be ignored
  - Bi-directional measurement medium flow
  - Large-diameter low flow, minimum flow can be measured down to zero, the resolution 0.001m / s
  - Up to 8 flow measurement
  - The use of proprietary technology, "double-balanced" package sensor
  - Not sensitive to vibration
  - Design, selection easy to install, easy to use
  - Straight pipe requirements smaller, 1D-2D can achieve high-precision measurement
  - Flow measurement independent of pressure and temperature, the real mass flow rate detection
  - SmartI using proprietary hardware and software Smart3000 for high temperature measurement (500 ℃)
  - The use of traffic data fuzzy theory algorithm, instrument measuring humidity, high temperature gas with high accuracy.
  - Proprietary algorithms can achieve high linearity, high repeatability, high accuracy

Technical Parameters

  Measuring range: 0-120Nm / s (20 ℃, 101.33KPa)
  Accuracy: ± 1% (of reading) ± 0.5% FS (full scale)
  Turndown ratio: typically 1000: 1 (depending on the flow rate of the calibration range)
Diameter range:
  Plug-in: DN50-6000mm
  Pipe-stage: DN15-2000mm
Applications: Suitable for all types of single or mixed gas. Dusty, sandy, containing moisture, corrosive gases
temperature range:
  Environment: -40 ℃ ~ + 85 ℃ (without display); -30 ℃ ~ + 70 ℃ (showing); humidity less than 90% RH
  Media: -40 ~ + 500 ℃
Process pressure: 1.6Mpa (maximum 20MPa)
Sensor diameter:
  Pipe-stage sensor diameter: ф3, ф2.5
  Plug-in sensor probe diameter: ф19 (standard), ф16, ф12
Materials:
  Sensor material: 316 stainless steel, Hastelloy, titanium
  Probe Material (Case): 316 stainless steel (standard), Hastelloy
output method:
  Analog output: Flow: 4-20mADC, temperature: 4-20mADC, maximum load: 1000Ω
  Cumulative pulse output
Communication Interface: serial output RS232 / RS485
Power supply: 24VDC / 600mA; 220VAC / 2W; 110VAC / 3W
Alarm: 1-2 relay outputs, 5A / 220V, 5A / 30VDC, type set ??
Display: large-screen LCD display, seven instantaneous flow, cumulative flow eight
Installation:
  Plug-in (card sets, card sets + ball valve, flange connection),
  Pipeline (flanged, threaded connections)
Explosion levels:
  Intrinsically safe (iaⅡCT5)
  Flameproof (ExdⅡCT4)
Protection class:
  Sensor: IP68
  Converter: one type IP67 IP65 wall-mounted split plate mounted IP52
Response time: 1s

Applications

Oxygen, nitrogen, hydrogen, chlorine, ammonia, and multi-component gas measurement.
Blast furnace gas, coke oven gas measurement.
Flue gas measurement.
Methane, water treatment aeration and chlorine measurement.
Compressed air measurements.
Natural gas, liquefied petroleum gas, flare gas, and other gas flow measurement.
Plant blast primary air, secondary air flow measurement.
Ventilation or exhaust flow measurement system of the mine.