| Flow Meter-Metal Tube Float Flowmeter |
| Details of the metal tube float flow meter : |
| TC-JSGF metal tube float flow meter The float is in the measuring tube. With the change of the flow rate, the float is moved upwards, and the buoyancy of the float at a certain position is balanced with the gravity of the float. At this time, the area of the circulating annulus between the float and the orifice plate (or cone tube) remains constant. The ring gap area is directly proportional to the rising height of the float, that is, the position where the float rises in the measuring tube represents the flow rate  Size, change the position of the float The indicator transmitted from the internal magnet to the outside makes the indicator correctly indicate the flow value at this time. This makes the indicator housing not in direct contact with the measuring tube, so even if a limit switch or transmitter is installed, the instrument can be used under high temperature and high pressure working conditions. |
Features TC-JSGF metal tube float flowmeter is a variable area flow measurement instrument commonly used in industrial automation process control. It has the characteristics of small size, large detection range and convenient use. It can be used to measure the flow of liquid, gas and steam, especially suitable for medium flow measurement with low flow rate and small flow. Measurement features: 1.Rugged all-metal structure design float meter 2.Measuring tube indicator with independent concept design 3.Select stainless steel, Hastelloy, titanium, PTFE material measurement system 4.Low pressure loss design 5.Short stroke, small structure design, total instrument height 250 6.Magnetic coupling structure ensures data transmission and more stable signal 7, insulation or heat tracing jacket 8, vertical, horizontal, various installation methods are more suitable for different use occasions 9.Suitable for small diameter and low flow medium flow measurement 10. Reliable work, small maintenance and long life 11.The requirements for straight pipe sections are not high 12. Wider traffic ratio 10: 1 13. Two-line large LCD display, optional on-site instantaneous / cumulative flow display, with backlight 14.Single-axis sensitive indication 15.Non-contact magnetic coupling transmission 16. All-metal structure, suitable for high temperature, high pressure and strong corrosive media 17.Can be used in flammable and explosive dangerous situations 18.Select two-wire system, battery, AC power supply method 19.Multi-parameter calibration function 20.With data recovery, data backup and power failure protection functions
Structural principle The flow detection element of the TC-JSGF metal float flowmeter is composed of a vertically tapered tube that expands from bottom to top and a float group that moves up and down along the axis of the cone tube. The working principle is shown in Figure 1. When the measured fluid passes from the bottom to the ring gap 3 formed by the cone 1 and the float 2, a differential pressure is generated at the upper and lower ends of the float to form a rising force of the float. When the floating force is greater than the immersion fluid When the weight of the float rises, the float rises, the area of the annulus increases, the flow velocity of the fluid at the annulus decreases immediately, the differential pressure at the upper and lower ends of the float decreases, and the rising force acting on the float also decreases until the rising force equals immersion in the fluid When the weight of the float is medium, the float is stable at a certain height. The height of the float in the cone has a corresponding relationship with the flow rate. The basic equation of volume flow Q is (1) when the float is a non-solid core hollow structure (load adjustment amount), then in formula (2) α-the flow coefficient of the meter, which varies with the shape of the float; ε-is The gas expansion coefficient when the measured fluid is gas is usually ignored due to the small correction amount of this coefficient, and it has been included in the flow coefficient through verification. If it is a liquid, ε = 1; △ F——circulation annular area, m2; g——local gravity acceleration, m / s2; Vf——volume of float, if it is extended, it should also include, m3; ρf——density of float material, kg / m3; ρ——density of measured fluid, if Gas is the density on the upstream cross section of the float, kg / m3; Ff-cross-sectional area at the working diameter (maximum diameter) of the float, m2; Gf-mass of the float, kg. The relationship between the circulation ring area and the height of the float is shown in equation (3). When the structural design has been determined, d and β are constant. There is a quadratic term of h in the formula. Generally, this nonlinear relationship cannot be ignored. Only when the cone angle is very small can it be regarded as approximately linear. m2 (3) where d——the maximum diameter of the float (that is, working diameter), m; h——the height of the float from the cone diameter equal to the maximum diameter of the float, m; β——the cone angle of the cone; a, b --constant. The typical structure of a 15-40mm transparent cone-shaped tube float meter is shown in Figure 2. The most commonly used transparent conical tube 4 is made of borosilicate glass, and it is customarily referred to as a glass tube float flow meter. The flow indexing is directly engraved on the outer wall of the cone tube 4, and an indexing scale is also installed beside the cone tube. The inner cavity of the cone tube has two types: a smooth surface of the cone and a rib (or plane) with a guide. The float moves freely in the cone tube, or moves under the guidance of the ribs of the cone tube, and the instrument with a smooth inner surface of a larger mouth is also guided by a guide rod. Figure 3 is a typical structure of a metal tube float flow meter with a right-angle installation method, which is usually applicable to instruments with a diameter of 15-40mm or more. The cone tube 5 and the float 4 constitute a flow detection element. There is an extension of the guide rod 3 in the sleeve (not shown in Figure 3), and the displacement of the float is transmitted to the conversion part outside the sleeve through magnetic steel coupling and other methods. The conversion part has two types: local indication and remote signal output. In addition to the right-angle installation structure, there is a straight-through structure with the inlet and outlet center lines concentric with the tapered tube, which is usually used for instruments with a diameter of less than 10-15mm.
The main technical parameters ◇ Measuring range: water (20 ℃) 1-200000 l / h Air (20 ،م C, 0.1013MPa) 0.03-4000m3 / h; see flow meter, special flow can be customized ◇ Range ratio: standard type 10: 1; special type 20: 1 ◇ Accuracy: standard type 1.5; special type 1.0 ◇ Pressure level: Standard type: DN15-DN50 4.0MPa DN80-DN200 1.6MPa Special type: DN15-DN50 25MPa DN80-DN200 16MPa Jacket pressure level is 1.6MPa; special models should be negotiated with the factory before selection and order ◇ Pressure loss: 7kPa-70kPa ◇ Media temperature: standard type: -80 ℃-+ 200 ℃: PTFE: 0 ℃ -85 ℃ High temperature type: up to 400 ℃ ◇ Viscosity of medium: DN15: η <5mPa.s (F15.1-F15.3) η <30mPa.s (F15.4-F15.8) DN25: η <250mPFa.s DN50-DN150: η <300mPa.s ◇ Ambient temperature: LCD type -30 ℃ － + 85 ℃ Pointer －40 ℃ － + 120 ℃ ◇ Connection form: Standard type: DIN2501 standard flange Special type: any standard flange or thread specified by the user ◇ Cable interface: M20 * 1.5 ◇ Power supply: Standard type: 24VDC two-wire system 4-20mA (10.8VDC-36VDC) AC type: 85-265VAC 50HZ Battery type: 3.6V@7.5AH lithium battery, which can be used continuously for more than three years. ◇ Alarm output: upper or lower limit instantaneous flow alarm Open collector output (maximum 100mA @ 30VDC internal impedance 100 ohms) Relay output (contact capacity 1A @ 30VDC or 0.25A@250VAC or 0.5A@125VAC) ◇ Pulse output: cumulative pulse output, minimum interval 50 ms ◇ LCD display: instantaneous flow rate display value range: 0-50000 Accumulated flow display value range: 0-99999999 (with decimal point) ◇ Protection level: IP65 ◇ Explosion-proof mark: intrinsically safe iaⅡCT5; flameproof dⅡBT6