转子流量计介绍（中英文）

第一章：转子流量计原理

Chapter 1: Principle of Rotameters

本章将讨论什么是转子流量计、它们的结构以及工作原理。

This chapter will discuss what rotameters are, their construction, and how they function.

什么是转子流量计？

What Is A Rotameter?

转子流量计是一种测量封闭管内单位时间流体体积流量的装置。转子流量计应用有多种类型，包括化学品注入/计量和储罐覆盖。转子流量计是一种使用带有封闭自由浮子的刻度玻璃管测量流体流量的仪表。

转子流量计也称为变面积流量计，用于测量液体或气体通过转子流量计的锥形管时的体积流量。液体或气体的流动使仪表的浮子升高，增加了介质可以通过的面积。流量越大，浮子升得越高。

A rotameter is a device that measures the flow of fluid volume per unit of time in a closed tube. There are several types of rotameter applications, including chemical injection/dosing and tank blanketing. A rotameter is a gauge for measuring fluid flow using a graduated glass tube with an enclosed free float.

Also known as variable area flow meters, rotameters are used to measure liquid or gas volumetric flow rates as they pass through the tapered tube of the rotameter. The flow of the liquid or gas raises the meter’s float, increasing the area through which the media may pass. The larger the amount of flow, the higher the float is raised.

转子流量计可用于吹扫应用，以保持工艺管线畅通。在简单的流量测量中，警报或电气输出可以检查流量状况并对其进行连续控制。

A rotameter can be used for purge applications to keep process lines clear. In simple flow measurement, an alarm or an electrical output makes it possible to check flow conditions and control them continuously.

转子流量计的构造

Construction of Rotameters

转子流量计包含一根底部直径较小的透明锥形垂直管。该管改变其横截面积，以便通过给予浮子恒定的下降来影响浮子。浮子的形状可以对流动产生更小的阻碍。

A rotameter contains a transparent, tapered, vertical tube with a small diameter at the bottom. This tube changes its cross-sectional area in order to affect the float by giving it a constant drop. The float is shaped to create minimum hindrance to the flow.

玻璃管的外缘标有线性刻度。锥形管可以由塑料、金属或玻璃制成，它们都有不同的用途；例如，不透明液体用于金属管，而气体管则含有其他气体和液体。此外，金属管可能使用不同密度的金属，包括铅和铝，而浮子主要由不锈钢制成。

A linear scale is marked on the outer margin of the glass tube. The conical tube can be made up of plastic, metal, or glass, with all of them having different uses; for example, opaque liquids are used in metal tubes, whereas gas tubes contain other gasses and liquids. In addition, metal tubes might use metals of different densities, including lead and aluminum, while the floats are mainly made of stainless steel.

转子流量计如何工作

How Rotameters Work

流体从底部进入管并从顶部逸出。这种流体就是其流量被测量的流体。当仪器中没有流量时，浮子将停留在管底部。在这种情况下，浮子的总直径几乎等于玻璃管的内径。

Fluid enters the tube from the bottom and escapes through the top. This fluid is the one whose flow is measured. The float will rest at the bottom of the tube when there is no flow in the instrument. In such a situation, the total diameter of the float is nearly equal to the inside diameter of the glass tube.

当流体进入管内时，环形开口的流通面积增大，从而使浮子向上移动。它向上移动，直到其上、下表面压力差产生的提升力开始等于浮子重量。由于转子流量计中流量的增加，升力和压差会暂时增加。随后，浮子移动到顶部并增加环形开口的面积。因此，升力将减小，流体的力将变得与浮子重量相同。通过改变与流量相关的环形开口的面积，压力差保持不变。玻璃管上标记的刻度表示流量。

The flow area of the annular opening increases when the fluid enters the tube, thus making the float move upwards. It moves upwards until the lifting strength produced from the difference in pressure across its upper and lower surfaces begins to equal the float weight. The lifting force and pressure difference will temporarily increase due to the flow rate increase in the rotameter. Afterward, the float travels to the top and increases the area in the annular opening. Due to this, the lifting force will decrease, and the force of the fluid will become the same as the float weight. The difference in pressure remains the same by changing the area of the annular opening in relation to the flow rate. The scale marked on the glass tube indicates the flow rate.

使用转子流量计时，必须在给定的条件下对给定的气体或流体进行校准。通常，条件及其流量范围和测量单位都写在流量计的侧面。在使用转子流量计时，始终建议根据流量条件的任何变化来校正流量管读数。通常，制造商会详细说明仪表所需的校正，但情况并非总是如此。

When using rotameters, calibration must be undertaken for a given gas or fluid at a given set of conditions. Normally, the conditions are written on the sides of the flow meter along with its range of flow and the units of measurement. In using rotameters, one is always advised to correct the flow tube readings according to any changes in flow conditions. Usually, manufacturers detail the required corrections for the meters, but this is not always the case.

转子流量计的工作原理

Working Principle of a Rotameter

转子流量计中使用的公式之一是：

Q=kA√GH

符号：

Q = 体积流量

k = 常数

A = 浮子和管壁之间的环形面积

g = 重力

h = 浮子的压降

One of the formulas used in the rotameters is:

Q=kA√GH

Where:

Q = volumetric flow rate

k = a constant

A = annular area contained between the float and the wall of the tube

g = the force of gravity

h = the pressure drop of the float

由于其优点，转子流量计成为使用广泛的变面积流量计。它由一个浮子组成，当流体通过时浮子会在管子中移动。由于体积而产生的更多流量对浮子施加更大的压力，从而将其提升得更高。在液体中，浮力与流动液体的速度合二为一，从而使浮子升高。在气体中，浮力被忽略为气体速度，压力将浮子分配到一定的高度。

通常，管子垂直设置，无流动，浮子位于底部。但当流体通过时，浮子开始上升到管的顶部。浮子移动时获得的高度通常与流体流动的速率成正比。当向上的力现在等于浮子的重量时，该过程达到平衡，同时也使浮子处于固定位置而不移动。此时，可以轻松读取读数，包括密度读数和流体的流动阻力（粘度）。

使用流量调节阀，可以手动调节转子流量计中的流量。转子流量计的名称源于早期的设计，早期的设备具有自由浮子，其随着气体和流体压力的变化而旋转。

Because of its advantages, a rotameter is the most widely used variable area flow meter. It consists of a float that moves through a tube as the fluid passes through. More flow due to volume exerts a greater pressure on the float, thus lifting it even higher. In liquids, buoyancy becomes one with the velocity of the flowing liquid, thus raising the float. In gasses, buoyancy is left out as the speed of the gas, and the pressure assigns the float to a certain height.

Commonly, the tube is set up vertically with no flow and the float at the bottom. But just as the fluid passes through, the float begins to elevate up to the top of the tube. The height gained by the float as it moves is generally proportional to the rate at which the fluid flows. The process reaches equilibrium when the upward force now equals the weight of the float, also giving the float a fixed position with no movement. At this moment, readings can be easily taken, including readings of the density and the fluid’s resistance to flow (viscosity).

Using flow regulation valves, one can manually adjust the flow in the rotameter. The name rotameter was gained from the early designs where the early equipment had free floats which rotated in relation to the change in gas and fluid pressures.

空气和水等常用流体已经随转子流量计提供了校准数据和读数刻度。制造商通常提供部分标准信息，例如校准表、标准流量值、列线图和计算尺。

Generally used fluids such as air and water already have their calibration data and reading scales provided together with the rotameters. The manufacturers normally provide part of this standard information, such as the calibration tables, standard flow values, nomographs, and slide rules.

转子流量计的特性

Characteristics of a Rotameter

转子流量计的线性度

Linearity of a Rotameter

面积与单位时间内流经变量流量计的体积成正比，从而使这些流量计具有相同刻度的增量。转子流量计刻度的线性度误差约为 5%。

The area is proportional to the volume flowing in a unit of time through a variable meter, thus making these meters have increments of equal scale. The linearity of a rotameter scale is amiss at about 5%.

转子流量计的微分

Differential of a Rotameter

在变面积流量计中，通过浮子的压力损失是恒定的。在较高流量下，由于配件中的摩擦损失，仪表中的压差会增加。

The loss of pressure through the float is constant in the variable area meter. At a higher flow rate, the differential in the meter increases due to the friction losses in the fittings.

转子流量计的精度

Accuracy of a Rotameter

常用的精度是刻度读数的 ±2%。由于用户的校准和刻度长度，该刻度精度大大提高。

±2% of the scale reading is the most-used accuracy. Due to the user’s calibration and the scale length, this scale accuracy increases considerably.

转子流量计的容量

Capacity of a Rotameter

水0.5cm 3 /min、空气30cm 3标准/min为流量计的大量程范围。

0.5 cm3 /min of water and 30 cm3 standard/min of air are the large-scale capacity range of the flow meters.

转子流量计更低的管道要求

Minimum Piping Requirement of a Rotameter

安装时无需考虑直管程序的连接或长度或遵循仪表。

Installations can be made without considering the connections or lengths of straight pipe procedures or following the meter.

转子流量计的腐蚀性液体

Corrosive Liquid of a Rotameter

油、焦油、硫酸和黑液都是腐蚀性液体，可以在面积计中正确处理。

Oil, tar, sulfuric acid, and black liquor are corrosive liquids that can be correctly handled in an area meter.

转子流量计的压降

Pressure Drop of a Rotameter

通过将浮子放置在较大的仪表上，流量可以处理非常低的压力损失。

The flow rates can handle a very low-pressure loss by placing floats on larger gauges.

概括

Summary

转子流量计的特点是结构简单，因此成本较低。由于大多数流量计都带有线性刻度，因此很容易读取读数。准确度在总读数的 ±2% 之内，允许读数出现一点误差。最后，转子流量计是一种易于安装的仪器。

A rotameter’s characteristics include its simple construction, thus providing a low cost. It is easy to take readings because the rotameter contains a linear scale with most meters. Accuracy, which is within ±2% of the total reading, allows a little room for errors in the readings. Lastly, the rotameter is an easy-to-install instrument.

转子流量计的组件

Components of a Rotameter

转子流量计的组件包括：

The components of a rotameter include:

转子流量计的计量管

Metering Tubes of a Rotameter

为了获得坚固且均匀的管子，计量管在心轴中制造并退火以消除内应力。这个过程使得计量管具有更高的再现性和更多的互换性。此外，还创建了带有弯曲元件的锥形计量管，以扩展范围下端的刻度。通常，安全屏蔽玻璃管用于测量液体和气体。金属管用于应用不透明液体、温度和压力要求非常高的区域。在一些转子流量计设计中，使用塑料管是因为其成本较低且抗冲击强度较高。

To obtain strong and uniform tubes, the metering tubes are created in a mandrel and annealed to have no internal stresses. This process leads to the metering tubes having greater reproducibility and more interchangeability. In addition, conical metering tubes with curved elements are created to extend the graduations at the lower end of the range. Generally, safety-shielded glass tubes are used for measuring both liquids and gasses. Metal tubes are used in areas where opaque liquids are applied, where temperature and pressure requirements are noticeably high. In some rotameter designs, plastic tubes are used due to their lower cost and high impact strength.

转子流量计的浮子

Floats of a Rotameter

浮子采用耐腐蚀和耐容量改变的材料制成，例如不锈钢。这些按照仪表的容量进行分组。转子流量计受被测流体粘度变化影响的方式可能受到浮子形状的影响或决定。具有尖角或边缘的浮子可能对粘度的变化不敏感。

作用在浮子上的力有三种：重量、浮力和阻力。重量是恒定的向下的力，而浮力是恒定的向上的力。阻力是具有向上方向的可变力。它们由不同密度的金属制成，例如铅和铝；也可以使用玻璃和塑料。浮子设计为球形，适合小流量。

The floats are made using materials that resist corrosion and capacity modification, such as stainless steel. These are grouped in terms of the capacities of the meters. The way in which a rotameter will be affected by changes in the viscosity of the fluid measured can be affected or determined by the shape of the float. Floats with sharp corners or edges are likely to be insensitive to changes in viscosity.

There are three forces that act on the float: weight, buoyancy, and drag force. Weight is a constant downward force, whereas buoyancy is a constant upwards force. Drag force is a variable force having an upward direction. They are constructed using metals of different densities, like lead and aluminum; glass and plastic can also be used. Floats are designed to be spherical for small flows.

转子流量计的特点

Features of a Rotameter

仪器必须包含声音或视觉警报，以提醒用户危险情况。仪器还必须包含控制器功能，以便正确使用和调谐仪器。这些有助于设备接收输入信号，并将其处理为输出信号，以便于通信。要更改转子流量计正在处理的命令，仪器必须是可编程的。这是通过在可编程仪表中插入内置微处理器来实现的。这些微处理器可以根据材料、范围和输出进行电子调节。

转子流量计必须包含一些记录器或累加器功能，因为它们可以累加受控材料和介质的数量。可以设置记录器功能来处理数据记录并将该数据记录在计算机系统中，以便将来使用，即使转子流量计未使用。该相同的功能稍后可以以显示的图表或表格的形式生成数据摘要。

最后，转子流量计可以适应卫生环境，例如医疗或食品加工场所。

The instruments must contain audible or visual alarms to alert users of a dangerous situation. The instruments must also contain controller functions for the proper use and tuning of the instruments. These help the devices receive an input signal that can be processed into an output signal for easier communication. To change the commands being processed by the rotameter, the instrument must be programmable. This is achieved by inserting a built-in microprocessor in the programmable meters. These microprocessors can be adjusted electronically depending on the materials, ranges, and outputs.

A rotameter must contain some recorder or totalizer functions, as these totalize the amount of material and media controlled. A recorder function can be placed to process data logging and record this data in a computer system so it can be used in the future, even if the rotameter is not in use. This same function can later produce a summary of the data in the form of displayed charts or tables.

Finally, rotameters can accommodate use in sanitary environments such as medical or food processing places.

转子流量计的精度

Accuracy of a Rotameter

实验室转子流量计可在 4:1 范围内校准至约 0.50% AR 的精度。工业转子流量计的准确度可能较低，因为在 10:1 范围内其精度为 1-2% FS。

可以在调整阀门开度并观察刻度的同时手动设置流量。由于粘度变化很小，转子流量计不会变化太大。这一点取决于设备的设计，因为使用球测量的设备最敏感，而较大的设备则不太敏感。粘度极限通常由浮子形状和构成转子流量计的材料决定。一旦仪器超过其粘度极限，就需要校正粘度读数。

如果流体密度发生变化，可以使用两个浮子。在这两个浮子中，一个取决于流体体积，另一个将校正流体密度。低粘度流体（例如汽油、喷气燃料和其他轻质烃）最适合使用质量流量转子流量计。由于浮力导致密度变化后，浮子位置可以改变，这是由于浮子密度与流体密度相匹配而引起的。

A laboratory rotameter can be calibrated to an accuracy of about 0.50% AR over a 4:1 range. Industrial rotameters are likely to be less accurate as these are 1-2% FS over a 10:1 range.

Flow rates can be manually set while tuning the valve opening and observing the scale. With small changes in viscosity, rotameters do not vary too much. This point depends on the equipment's design, as those that use ball measurements are the most sensitive, and larger ones are less sensitive. The viscosity limit is usually determined by the float shape and the material making up the rotameter. Once the instrument passes through its viscosity limit, the viscosity readings will need to be corrected.

If the fluid density is subject to change, one can use two floats. Of these two floats, one will depend on the fluid volume, and the other will correct the fluid density. Low-viscosity fluids such as gasoline, jet fuel, and other light hydrocarbons work best with mass flow rotameters. The float position can be changed after the density changes due to buoyancy, which is caused by matching the float density with the fluid density.

转子流量计的安装选项

Mounting Options of a Rotameter

转子流量计必须垂直安装，更宽端位于顶部。安装转子流量计的一些选项包括插入式、同轴法兰式、同轴螺纹式和同轴夹具式。

安装插入式流量计时，必须确保其垂直于流路。这些通常需要在工艺管道上有螺纹孔。在线法兰流量计应与流动路径平行，流动路径必须位于两个现有的法兰过程管道之间。当内嵌螺纹流量计插入两个已有的过程管道时，流路必须与内嵌螺纹流量计平行。在螺纹类型中，NPT 是最常见的。

Rotameters must be mounted vertically, with the widest end at the top. Some options for mounting rotameters are insertion, in-line flanged, in-line threaded, and in-line clamp.

When mounting insertion flow meters, one must ensure they are perpendicular to the flow path. These usually require a threaded hole in the process pipe. In-line flanged flow meters should be parallel to the path of flow, which must be between two existing pieces of flanged process pipes. The flow path must be parallel to the in-line thread flow meter as they are inserted into the two already-existing process pipes. Of the thread types, NPT is the most common.

转子流量计的操作流程

Handling Process of a Rotameter

转子流量计由玻璃制成，因此需要小心避免破裂。操作转子流量计时，请勿将其设置为0，因为它会阻碍加压空气的流动并造成损坏。必须尽一切努力避免视差误差；因此，为了看得清楚，可以使用酒精棉签清洁玻璃外层。最后，浮子容易卡在流量计底座中，导致空气堵塞而无输出。将流量计倒置有助于尝试将浮子从底座上移开。

A rotameter is made of glass, so care is required to avoid breaking it. When operating the rotameter, do not set it to 0, as it hinders the flow of the pressurized air and causes damage. Parallax error must be avoided by all means; therefore, to see properly, an alcohol swab may be used to clean the outer layer of the glass. Finally, the float tends to get stuck in the base of the flow meter, leading to blocked air and no output. Turning the flow meter upside down can be helpful in trying to move this float from the base.

第 2 章：转子流量计的类型

Chapter 2: Types of Rotameters

转子流量计可用于各种应用，每一种都有独特的元素。转子流量计的类型有玻璃管流量计、铠装吹扫流量计、法兰铠装转子流量计。下面将详细解释这些内容。

Rotameters can be used in various applications, and each one has unique elements. The types of rotameters include glass tube flow meters, armored purge meters, and flanged armored rotameters. These are explained in detail below.

玻璃管转子流量计

Glass Tube Rotameters

玻璃管转子流量计广泛应用于工业领域、实验室和其他中试工厂。硼硅酸盐玻璃通常用于制造管子。为了抵抗腐蚀，浮子由不锈钢、玻璃或塑料制成。由于其锋利或计量边缘，浮子反映了秤上的特定读数。根据其使用领域，通常将连接件或端部配件放置在转子流量计上。

Glass tube rotameters are extensively used in industrial areas, laboratories, and other pilot plants. Borosilicate glass is usually used to make the tube. To resist corrosion, the float is manufactured with stainless steel, glass, or plastic. The floats reflect a specific reading on the scale due to their sharp or metering edges. A connection or an end-fitting is usually placed on the rotameter in relation to its field of use.

标准化更重要的部分是管浮子组合，因为它执行测量。查找表可以将提供的单位转换为相关流体的流量。对于氮气、氧气、氢气、氦气、二氧化碳和氩气等气体，可以通过相关表检查转子流量计的相关刻度。这种方法更准确，因为在特定的温度和压力下已经确定了空气或水的比例，但它可能不太方便。

可以使用许多不同的浮子来测量不同的流体流速。将玻璃管转子流量计放置在视线水平位置可以使刻度读数更容易记录。玻璃管转子流量计不能用于其他类型的流体，例如超过 194 °F (90 °C) 的水、高 pH 值流体以及会软化管玻璃的湿蒸汽。玻璃也会被烧碱和氢氟酸溶解，因此必须使用其他管子。玻璃管转子流量计的性能受到玻璃管压力和温度的限制，其中较高的温度是主要限制因素。

玻璃管转子流量计在混合或输送多种气体或液体流的区域中非常有效，尽管它们在一种流体流经多个通道的情况下也很有效。

The most important part of standardizing is the tube float combination since this carries out the measurements. Lookup tables can convert the provided units into flows of the relevant fluids. For gasses like nitrogen, oxygen, hydrogen, helium, carbon dioxide, and argon, the correlation scales of the rotameter can be checked with the correlation tables. This way is more accurate, as scales of air or water would have already been determined under specific temperatures and pressures, but it can be less convenient.

Different fluid flow rates can be measured using many different floats. Placing a glass tube rotameter at eye level can make the scale readings easier to record. Glass tube rotameters cannot be used for other types of fluids, such as water over 194 °F (90 °C), high pH fluids, and wet steam, which softens the glass of the tube. Glass is also dissolved by caustic soda and hydrofluoric acid, so other tubes must be used. The performance of a glass tube rotameter is limited by the limits in pressure and temperature of the glass tube, where higher temperatures are the major limiting factor.

Glass tube rotameters are effective in areas where several streams of gasses or liquids are mixed or transported, though they can also be effective where one fluid flows through several channels.

10A6130 玻璃管吹扫和低流量计

10A6130 Glass Tube Purge and Low Flow Meters

这更适合需要低流量的应用，包括吹扫控制管线和仪器外壳。该仪器更适合流体采样、液位测量、液体比重以及气体和液体的低流量使用。它由 (112, 3, 10”) 长度和 1/4” NPT 连接组成。

This is best for applications requiring a low flow rate, including purging control lines and instrument enclosures. This instrument is best for fluid sampling, level measurement, liquid specific gravity, and low-flow uses of gasses and liquids. It consists of lengths of (112, 3, 10”) with connections of 1/4” NPT.

10A4500 玻璃管流量计

10A4500 Glass Tube Flow Meters

它存在于大多数市政和工业设施中，用于测量液体和气体。它作为烤箱和熔炉的一部分安装，用于跟踪天然气流量，从而可以冷却流体以保护设备。

This is found in most municipal and industrial facilities and is used to measure liquids and gasses. It is installed as part of ovens and furnaces to keep track of natural gas flow, thus making it possible to cool down fluids to protect equipment.

10A2235 玻璃管转子流量计

10A2235 Glass Tube Rotameters

它用于在轴承润滑剂流量过低时自动关闭重型设备。当冷却水量低于一定限度时，它还会关闭电气设备。

It is used to automatically turn off heavy equipment when the flow of the bearing lubricant gets too low. It also shuts down electrical equipment when water that is being cooled decreases below a certain limit.

铠装净化流量计

Armored Purge Meters

这更适合市政和工业内低流量和高压的区域。它还用于气体分析仪系统以及出于安全考虑玻璃管不适合的地方。这些转子流量计非常适合测量浑浊和不透明的介质。铠装净化流量计的一个优点是，如果系统状况不佳，它可以净化流体。 10A3200 是铠装吹扫流量计的一个示例，它具有 NPT 螺纹和针阀选项。

This is best for areas with low flow and high pressure within municipalities and industries. It is also used in gas analyzer systems and where glass tubes are unsuitable for safety concerns. These rotameters work well with measuring cloudy and opaque media. An advantage of an armored purge meter is that it purges the fluid if a system’s condition is not well. One example of an armored purge meter is the 10A3200, which is available with NPT threads and a needle valve option.

法兰铠装转子流量计

Flanged Armored Rotameters

这通常用于工业和其他专门从事制药和石化产品的自动化系统。它可以测量强条件下的不透明流体和非导电流体。法兰铠装转子流量计最适合高压用途。 FAM54 是法兰铠装转子流量计的一个示例，它包括法兰连接。该转子流量计的用途包括可选警报、HART 通信、累加器脉冲输出、数字显示器和发射器。

This is usually used in industries and other automated systems which specialize in pharmaceuticals and petrochemicals. It measures opaque fluids under forceful conditions and non-conductive fluids. A flanged armored rotameter is most suitable for high-pressure uses. An example of a flanged armored rotameter is the FAM54, which includes flanged connections. This rotameter’s uses include optional alarms, HART communications, totalizer pulse outputs, digital displays, and transmitters.

金属管转子流量计

Metal Tube Rotameters

金属管浮子流量计具有由钢制成的锥形管和由不锈钢或聚四氟乙烯（PTFE）制成的浮子。 它们非常耐用、持久，具有卓越的强度，并且经过精心设计，适合测量高压或高温下的腐蚀性或浑浊液体。 金属管转子流量计具有防爆功能，具有高精度和可靠性，非常适合在恶劣、有压力的条件下使用。

在金属管浮子流量计中，磁性传感器和芯片技术可产生流量、累积流量和百分比流量的 LCD 读数。传感器的磁耦合提供更稳定的信号传输。

在非铁磁金属管转子流量计中，浮子使用磁铁，并在锥体外部安装从动磁铁来跟踪浮子的位置。从动磁铁机械连接到视觉指示器或读出装置。

A metal tube rotameter has a tapered tube made of steel and a float made of stainless steel or polytetrafluoroethylene (PTFE). They are highly durable and long-lasting, with exceptional strength, and are engineered to be suitable for measuring corrosive or turbid liquids from high pressure or temperatures. Metal tube rotameters are explosion-proof with high accuracy and dependability, making them ideal for use in harsh, stressful conditions.

In a metal tube rotameter, a magnetic sensor and chip technology produces an LCD readout of the flow, accumulated flow, and percentage flow. A magnetic couple of the sensor provides a more stable signal transmission.

In non-ferromagnetic metal tube rotameters, the float uses a magnet with a follower magnet mounted outside the cone to track the float's position. The follower magnet is mechanically connected to a visual indicator or readout device.

第 3 章：转子流量计的应用和优点

Chapter 3: Applications and Benefits of Rotameters

本章将讨论转子流量计的应用和优点。

This chapter will discuss the applications and benefits of rotameters.

转子流量计的应用

pplications of Rotameters

转子流量计在市政和工业中用于精确的液位测量。它们用于净化腐蚀性液体。转子流量计测量和控制机械；例如，当冷却机达到某个标记点时，它们可能会关闭冷却机。它们也是需要持续润滑的机械中的有效设备。

转子流量计用作气体分析仪，用于识别含有多种气体的大气中已知气体的浓度。精确的密度转子计也用于有效测量。工业现场的熔炉和煤气燃烧器需要控制，以免损坏设备；因此，采用转子流量计进行监测。该设备还用于工业中的制冷流量控制。

Rotameters are used in municipalities and industries for accurate level measurements. They are used in the purging of corrosive fluids. Rotameters measure and control machinery; for example, they may shut down a cooling machine as it reaches a certain marked point. They are also effective equipment in machinery that requires continuous lubrication.

Rotameters are used as gas analyzers to identify the concentration of known gasses in an atmosphere that contains many. Accurate density rotameters are also used for effective measurement. Furnaces and gas burners in industrial sites need to be controlled not to damage equipment; therefore, rotameters are used for monitoring. This equipment is also used in industries for refrigeration flow control.

转子流量计的优点

Benefits of Rotameters

• 转子流量计价格便宜且容易获得。

• 转子流量计可以测量具有小或中等速度的流体，例如1LPM至10LPM的速度。

• 金属和玻璃转子流量计盖具有高度惰性，使其能够抵抗化学反应。由于这种惰性，该设备非常适合与腐蚀性液体一起使用。

• 使用转子流量计读取读数很简单，因为它提供线性测量刻度，从而提供更高的精度和准确度。

• 转子流量计不需要测量物质之外的任何外力，减少了读数不准确的情况。

• 由于其小型设计，它们可用于广泛的系统中。

• Rotameters are cheap and easily available.

• Rotameters can measure fluids with a small or medium velocity, e.g., a velocity of 1 LPM to 10 LPM.

• Metal and glass rotameter covers are highly inert, allowing them to resist chemical reactions. Due to this inertness, the equipment is good to use with corrosive fluids.

• Taking readings with a rotameter is simple as it provides a linear measurement scale, providing higher precision and accuracy.

• Rotameters do not require any external force outside the measuring substance, reducing inaccurate readings.

• Because of their small design, they can be used in a wide range of systems.

转子流量计的缺点

尽管转子流量计在某些领域很有用，但它们仍然有缺点。

• 在仪器运输或维护过程中，随着流体压力随时间增加，转子流量计的外玻璃层很容易破裂。

• 由于难以看到计量浮子，因此很难使用不透明的流体进行测量。

• 如果用户的眼睛没有与测光浮标对齐，视差误差可能会影响结果。测量时请保持仪器直立，避免倾斜，以免结果不准确。

• 分辨率比其他测量原理差。

• 转子流量计不如其他仪器（如文丘里流量计或孔板流量计）坚固，因为它使用玻璃管。

• 转子流量计对于测量波动的流体流量效果较差。

• 它们不适用于含有悬浮固体颗粒的液体。

• 转子流量计的精度不如文丘里流量计或孔板流量计。

Drawbacks of Rotameters

Despite rotameters being useful in some areas, they still have drawbacks.

• A rotameter’s outer glass layer can easily break as the pressure in the fluid increases over time, while the instrument is in transport, or while it is being maintained.

• It can be hard to take measurements with non-transparent fluids because the metering float is difficult to see.

• If the user’s eyes are not aligned with the metering float, parallax errors may affect the results. Hold the instrument upright and avoid tilting to avoid inaccurate results during measurement.

• The resolution is poorer than other measurement principles.

• A rotameter is less sturdy than other instruments, like a Venturi meter or orifice meter, because it uses a glass tube.

• Rotameters are less effective for measuring fluctuating fluid flow rates.

• They are unsuitable for liquids with suspended solid particles.

• A rotameter is less accurate than a Venturi meter or orifice meter.

选择转子流量计时要考虑的因素

Factors to Consider When Choosing a Rotameter

• 流量——流量是选择转子流量计时要考虑的第一个参数。两种类型的流量是液体体积流量和气体体积流量。液体体积流量仅用于液体体积流量计。该速率表示为每单位时间体积流量的变化。同时，气体体积流量仅适用于气体体积流量传感器，以单位时间内气体体积的变化来表示。

• 工作压力——工作压力代表仪表能够承受的介质总压力。操作压力很重要，因为它可以通过改变气体密度来影响气体。

• 流体温度——衬里和结构材料的公差决定了可以使用的流体的温度。

• 管道直径——在安装过程中，为了了解转子流量计的正确尺寸，必须考虑管道直径。

• 量表类型——必须标明量表类型，如百分位数，以帮助记录。

• 阀门要求——针阀是最常用的。

• 在线法兰流量计——用户必须确保在线法兰流量计与流动路径平行，该流动路径必须位于两个现有的法兰过程管道之间。

• 安装仪表（侵入式与非侵入式） ——某些仪表，例如外部夹式流量计，不需要直接安装到过程流上。这些被称为非侵入式仪表，可用于封闭管道系统。

• 端部配件——端部配件可能包括压缩配件，通过将套筒拧紧在接头上来防止泄漏，或承插焊/活接头（可以是焊颈）。

• 操作条件——转子流量计具有最小和最大流量，具体取决于压力和温度。

• 所需的精度——必须了解使用设备所需的精度。

• 直观的读数——转子流量计必须能够提供直观的读数。

• 管道尺寸——每个转子流量计都需要安装在自己的管道内。

• 流量调节阀——流量调节阀是可选的，但它们的用途取决于转子流量计的用途。

• Flow rate – Flow rate is the first parameter to consider when selecting a rotameter. Two types of flow rates are liquid volumetric flow rate and gas volumetric flow rate. Liquid volumetric flow rate is used only in liquid volumetric flow meters. This rate is expressed as the change in volume flow per unit of time. Meanwhile, gas volumetric flow rate only applies to gas volumetric flow sensors and is expressed in the change in gas volume per unit of time.

• Operating pressure – Operating pressure represents the total pressure of media that the meter can withstand. Operating pressure is important as it can affect gas by changing its density.

• Fluid temperature – The tolerance of the liner and construction materials determines the temperature of the fluid that can be used.

• Pipe diameter – The pipe diameter is important to consider during the installation process to understand the rotameter’s correct dimensions.

• Scale type – Scale types, like percentiles, must be indicated to help in record-taking.

• Valve requirements – The needle valve is the most commonly used.

• In-line flanged flow meters – Users must ensure in-line flanged flow meters are parallel to the path of flow, which must be between two existing pieces of flanged process pipes.

• Mounting meters (invasive vs. non-invasive) – Some meters, e.g. external clamp-on flow meters, don’t need to be mounted directly to the process flow. These are called non-invasive meters and can be used in closed piping systems.

• End fittings – End fittings may include compression fittings, which prevent leakage by tightening down a sleeve over a joint, or a socket weld/union, which can be a weld neck.

• Operating conditions – Rotameters have minimum and maximum flow rates depending on the pressure and temperature.

• Needed accuracy – One must understand the accuracy needed in using the equipment.

• Straightforward readings – A rotameter must be able to provide straightforward readings.

• Pipe size – Each rotameter needs to fit inside its own pipe.

• Flow regulation valves – Flow regulation valves are optional, but they can be useful depending on the use of the rotameter.

结论

Conclusion

转子流量计，也称为变面积流量计，是用于测量液体或气体通过锥形管时液体或气体体积流量的仪器。当需要将成本保持在最低并且不需要高精度时，最好考虑转子流量计。

Rotameters, also known as variable area flow meters, are instruments used to measure the liquid or gas volumetric flow rate as either a liquid or gas passes through a tapered tube. The rotameter is best considered when the cost is to be kept at a minimum and when high accuracy is not required.

声明：

- 文章转载自IQS DIRECTORY，由爱泽工业翻译，如有侵权，请联系删除！

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