是运用差压式的工作原理，插入式的安装方法，设计生成的一种流量传感器。 Delta flowmeter is a flow sensor designed and produced by using the working principle of differential pressure and plug-in installation method. The pressure taking method is through a probe (or probe) with a diameter of about 20 millimeters. There are two rows of 8 mm impulse pressure holes that are unevenly distributed in front and back of the probe. Through the two rows of holes, the different pressures (/ flow rates) of the pipe from top to bottom (/ left to right) are averaged in the hole, (because the flow velocity on the two sides of the pipe is slow and the middle is fast) constitutes a differential pressure, which can be calculated. Out of mass flow or volume flow.
Scope of application
1. Nominal pressure: 25mm≤DN≤6000mm
2. Nominal pressure: PN≤25MPa
3. Medium temperature: t≤650 ℃
4. Accuracy level: 0.2 level, 0.5 level, 1 level, 1.5 level
Small pipeline power loss (small pressure loss): The pressure loss of the average speed tube is much smaller than that of the orifice plate, only 5 ~ 10% of the orifice plate; on the other hand, due to the small pressure loss, the differential pressure will be small. (The pressure difference between high pressure and low pressure) makes the requirements for selecting a differential pressure transmitter increase and the cost increases, otherwise the output accuracy of the transmitter will be lowered because the range cannot be achieved. Therefore, a good probe must take into account both pressure loss and differential pressure. Delta Taba ’s curved surface design fully considers this factor. The cross section itself is symmetrical. The curved surface is divided into three parts (as shown below), and the facing surface is divided into smooth sections to make the probe smoothly contact the medium. The second part is the acceleration section. The velocity of the medium is accelerated three times on average. By increasing the contact surface with the medium, the pressure on the oncoming section is increased; the third part is the high and low pressure boundary spikes, and the sudden resistance disappears, forming a low pressure area behind the probe. The actual color velocity spectrum can fully reflect Changes in the flow rate of the medium. Therefore, the design of the Delta Tab probe meets the requirements of small pressure loss and large differential pressure.
After third-party testing, and according to the latest data, it shows that 2% accuracy can be achieved even with relatively short straight pipe sections. The straight pipe section that achieves 1% accuracy is much shorter than ordinary products, as shown below. Repeatability is 0.1%. Because the pressure loss is small, the wear on the probe is small. As long as it is properly installed, it can maintain high accuracy for a long time. Low operating cost: Due to the small pressure loss, the power loss in the pipeline is small. Generally speaking, the operating cost of the averaging tube is only one tenth of that of the orifice plate. Small installation workload: Because the sensor is a plug-in working method, it has the characteristics of simple installation. For most diameters, just make a small hole in the pipe. According to many years of installation experience, it takes 5 minutes to open the hole, 20 minutes to weld the probe sleeve, 10 minutes to insert the fixed probe, 5 minutes to install the three valve group, 10 minutes to install the differential pressure transmitter, and 10 minutes to connect. The whole process takes about 60 minutes. Minutes (integrated). 的探头是整整意义上的一体化探头，无论被测介质是气体还是液体，或是高温的过热蒸汽，可以将差压探头、温度和压力的测量以及差压变送器在一根探头上安装，在探头与差压送器之间的连接方式有10多种(选择)，有专门为过热蒸汽的冷凝器，有用于直接连接变送器的椭圆法兰，也有简单的R1/2″外螺纹，提供分体/一体化安装的各种连接，能够满足各种需求。对于过热蒸汽，大多数产品均要求分体安装，用户必须自己配冷凝器和其它配件。而德塔巴连同冷凝器，截止阀或者球阀均一并提供，安全可靠，简单可行，是真正的一体化探头。 Free choice of integrated / split installation: The probe of the Delta Taba flowmeter is a complete integrated probe. No matter the medium to be measured is gas or liquid, or high temperature superheated steam, the differential pressure probe, temperature and pressure can be The measurement and differential pressure transmitter are installed on a probe, there are more than 10 (optional) connection methods between the probe and the differential pressure transmitter, there is a condenser for superheated steam, and there is a direct connection transmission The oval flange of the device also has a simple R1 / 2 ″ external thread, which provides various connections for split / integrated installation, which can meet various needs. For superheated steam, most products require split installation, and the user must himself Equipped with condensers and other accessories. Detabar is provided together with condensers, globe valves or ball valves, which is safe, reliable, simple and feasible, and is a truly integrated probe.
Holes are not easy to plug:
For flue gas measurement or gas / liquid measurement with particles, clogging is a concern for most users. If the dust in the medium is not greater than 130mg / m3, no maintenance or purging is required for the Delta Tab probe. From the perspective of fluid mechanics, wedges of any shape in the fluid will have fluid accumulation at the front end, which will increase the pressure and reduce the pressure after the wedge. Dust in motion will be no matter how high the pressure is and how low the pressure is. It is possible to enter the hole in the wedge. When the fluid is still, due to Brownian motion, the dust will enter the inner hole of the wedge. So the problem is not the pressure level, nor any cross section, but how to make the dust out and not accumulate. There is no doubt that timed purge is a solution. Our company has done a lot of research on the distribution and aperture of the holes on the probe. Foreign matter with a large aperture (8 mm) is easy to enter and exit. The small aperture will undoubtedly make it difficult to enter or exit, and the entry is absolute, and it is only a matter of time.
The DEC-DTB Delta Taba flowmeter is composed of a detection rod and a pressure taking port. It crosses the interior of the pipe and is perpendicular to the tube axis. There are multiple total pressure detection holes on the upstream surface of the detection rod, and on the backflow surface of the detection rod. There are multiple static pressure detection holes, which are led out by the total pressure impulse pipe and the static pressure impulse pipe respectively, and the flow rate through the pipeline is calculated according to the differential pressure value of the total pressure and the static pressure.
The DEC-DTB Delta Taba flowmeter is developed based on the principle of pitot tube speed measurement. It determines the flow rate by the product of the average velocity of the pipeline and the effective cross-sectional area of the pipeline. 1. Probe cross-sectional shape: Verabar is a bullet head shape, Delta Taba is a rhombus-like shape, and the rhomboid-like shape is cut to make the boundary between the high and low areas more obvious.
的全压孔也在杆前端，但静压孔却在杆的后端，测量背压力（负压）。 2. The position of the pressure hole of the probe rod: The full pressure hole of Verabar is at the front end of the rod, and the static pressure holes are at the two side walls of the rod; At the rear end, measure the back pressure (negative pressure).
Therefore, under the same pipe diameter and flow rate conditions, the differential pressure produced by the Delta Tab probe is larger than that of the Verabar probe, about 20% -40% larger. This is a significant advantage of the Delta Taba flowmeter.