Liquid mass flowmeter is a high-precision mass flow measurement instrument. Due to its excellent performance, high measurement accuracy, low requirements for fluid state, and small pressure loss. Various specifications of instruments can directly obtain the mass flow rate, volume flow rate, density, and temperature of the measured liquid or slurry, without the need for manual calculation or estimation. It can exhibit excellent performance even in harsh working environments. It has no moving parts inside, does not require complex installation, and does not have strict requirements for working conditions. Each sensor is made of stainless steel material, and the multiple outputs of the transmitter can meet your various needs.

Liquid mass flowmeter is a type of mass flowmeter that can display both volumetric and mass flow rates. The product adopts laminar flow principle and has no movable components or thermal elements inside. It has passed anti vibration testing and is insensitive to installation direction. It has a unique exhaust hole that can easily discharge air. This product is used for precise continuous measurement of cumulative or instantaneous flow rate of liquid in pipelines, and is suitable for university and research institute experiments, process manufacturing, food analysis, analytical testing and other places.

Characteristics of Liquid Mass Flow Meter

High precision, good repeatability, stable signal

Digital signal, data can be linked to a computer for data export

Short preheating time and small collar float

Not affected by installation orientation

Small size, easy installation, and convenient use

Model number	CB-F1	CB-F2	CB-F3
Flow range	0~1L/min	2~5L/min	5~20L/min
accuracy	±0.3%-2%F.S
linearity	±0.2~0.3%F.S
repeatability	±0.2%F.S
Response time	Electrical characteristics: 10sec Liquid characteristics: (1~4) sec
Working pressure differential	Working pressure difference 0.1~0.5MPa
Withstand voltage	2.0MPa
Operating ambient temperature	0~70℃
Digital quantity	RS485 MODBUS agreement
Power supply	DC +24V, power supply current greater than 500mA
Electrical connection	DB15
Leakage rate	1×10^-8 SCCSHe
Base material	316L Stainless steel
Sealing material	Fluororubber, butadiene, neoprene
Gas connection	74° Taper external thread M18*1.5

I. Principle

(1) Coriolis force principle

Basic concept

Many liquid mass flowmeters operate on the Coriolis force principle. When liquid flows through a pipe in rotating motion, the pipe becomes distorted due to the Coriolis force. This deformation is proportional to the mass flow of the liquid.

Working mechanism

Specifically, the liquid passes through the vibrating U-shaped tube or double-tube structure, causing the pipe to produce periodic vibration. When a liquid flows into a pipe, according to Newton’s Second Law and Coriolis’s law of force, the pipe is subjected to a force related to the mass flow of the liquid, causing a slight distortion in the pipe. This distortion is detected by a sensor mounted on the pipe, and the mass flow rate of the liquid can be obtained after signal processing.

(2) Thermal principle

Relationship between heat transfer and flow rate

The thermal liquid mass flowmeter uses the relationship between heat transfer and liquid mass flow to measure flow. Inside the flowmeter, there is a heating element and at least two temperature sensors. As the liquid flows through, the heating element transfers heat to the liquid.

Flow calculation method

According to the law of heat transfer in the liquid, the heat taken away by the liquid with different mass flow is also different. By measuring the temperature difference between the upstream and downstream of the heating element, combined with the calibration coefficient and the thermophysical characteristics inside the flowmeter, the mass flow rate of the liquid can be calculated. This principle is especially suitable for the measurement of small flow and low viscosity liquids.

Ii. Types

(A) Coriolis mass flowmeter

Monosiphonous type

The single tube Coriolis mass flowmeter is relatively simple in structure and consists of a vibrating pipe. When the liquid flows in the pipeline, the vibration characteristics of the pipeline will be changed by the liquid mass flow rate. Its advantage is that the cost is low, and it is suitable for some occasions where the accuracy requirement is not very high, such as the raw material transportation and measurement of small chemical enterprises.

Disiphonous type

The two-pipe Coriolis mass flowmeter uses two parallel vibrating pipes through which the liquid passes separately. This structure provides higher accuracy and stability, and dual tube flowmeters are a good choice for high-precision measurement applications, such as the measurement of liquid ingredients during drug formulation in the pharmaceutical industry.

(2) Thermal mass flowmeter

plug-in

The sensor part of the plug-in thermal mass flowmeter can be inserted into the pipe. This design allows it to be installed and measured without affecting the normal operation of the pipeline, especially for the flow measurement of large diameter pipelines. For example, in the main pipe flow monitoring of urban water supply systems, plug-in thermal mass flowmeters can be easily installed and data collected.

Tubular type

The tubular segment thermal mass flowmeter is installed with the whole flowmeter as a section of the pipe. Its advantage is that the measurement accuracy is high, because the flow state of the liquid inside the flow meter is easier to control and calibrate. In the refining process of petrochemical industry, tubular thermal mass flowmeters can accurately measure the mass flow of various liquid raw materials and products.

Iii. Application

(1) Chemical industry

Raw material ratio

In chemical production, accurate raw material ratio is the key to ensure product quality. Liquid mass flow meters can accurately measure the mass flow of various raw materials, such as ammonia, sulfuric acid and other raw materials in the production of fertilizer, so as to ensure that the chemical composition of the product meets the standard.

Reaction process monitoring

For chemical reaction processes, real-time monitoring of the mass flow of liquid reactants and products helps optimize reaction conditions. For example, in polymerization reactions, by measuring the mass flow of monomers and initiators, the reaction rate and molecular weight distribution of the polymer can be better controlled.

(2) The petroleum industry

Crude oil delivery measurement

In the process of crude oil extraction, transportation and trade, accurate flow measurement is very important. Liquid mass flow meters can provide high-precision crude oil mass flow data to ensure the fairness and accuracy of oil companies in crude oil trading.

Refining process control

In the refinery, from the distillation and cracking of crude oil to the allocation of various refined oil products, liquid mass flowmeters play an important role. It can accurately measure the mass flow of various oil products in different process stages, so as to improve refining efficiency and ensure the quality of finished oil products.

(3) Food and beverage industry

Beverage production

In the beverage production process, liquid mass flowmeters are used to accurately measure the mass flow of various raw materials such as water, juice, syrups, etc. For example, in the production of carbonated beverages, accurate control of the mass flow of carbon dioxide and syrup can ensure the consistency of the taste and quality of the beverage.

Food processing

In the food processing process, such as the measurement of milk, cream and other liquid raw materials in the processing of dairy products, as well as the control of the amount of soup added in the production of canned food, the liquid mass flowmeter can provide accurate flow data to ensure the stability of food quality.