電動執(zhí)行器和氣動執(zhí)行器實(shí)用指南（中英文）
雖然電動執(zhí)行器和氣動執(zhí)行器各有優(yōu)勢，并且在不同的應(yīng)用中是首選，但選擇錯誤的執(zhí)行器可能會造成嚴(yán)重后果。然而，在兩者之間做出選擇可能會讓人感到困惑。本文將探討氣動執(zhí)行器和電動執(zhí)行器的工作原理和區(qū)別，并比較分析它們的特性，以幫助用戶根據(jù)應(yīng)用選擇合適的執(zhí)行器。
閥門執(zhí)行器是一種自動化設(shè)備，用于遠(yuǎn)程控制閥門，無需人工干預(yù)。這些設(shè)備根據(jù)接收到的信號產(chǎn)生運(yùn)動來控制閥門。執(zhí)行器安裝在需要控制的閥門上，取代手動桿。不同型號的執(zhí)行器連接閥門和執(zhí)行器的安裝方式有所不同。
閥門執(zhí)行器可根據(jù)其產(chǎn)生打開閥門所需的扭矩（或力）的方式進(jìn)行大致分類。根據(jù)這種分類，最常見的兩種執(zhí)行器類型是電動執(zhí)行器和氣動執(zhí)行器。電動閥門執(zhí)行器利用電力產(chǎn)生所需的運(yùn)動，而氣動執(zhí)行器則利用壓縮空氣系統(tǒng)。第三種類型的閥門執(zhí)行器稱為液壓執(zhí)行器，但不太常見。
While electrical and pneumatic actuators have several unique benefits and are preferred in different applications, using the wrong one for your application can have serious consequences. However, choosing between them can be quite confusing. This article explores the working principles and differences between pneumatic and electric actuators, before comparatively analyzing their features to help you choose the right one for your application.
Valve actuators are automation devices that are used to remotely control valves without human intervention. These devices generate motion to control valves based on signals received. Actuators are mounted on the valves to be controlled, replacing manual levers. The mounting features that connect a valve to an actuator vary in different actuator models.
Valve actuators are broadly classified based on how they generate the torque - or force - required to open a valve. Based on this classification, the two most prevalent types of actuators are electric and pneumatic actuators. Electric valve actuators utilize electricity to produce the required motion, while their pneumatic counterparts utilize compressed air systems. The third type of valve actuator, known as hydraulic actuators exist, but these are less prevalent.
電動執(zhí)行器
Electric actuators
電動執(zhí)行器將電能轉(zhuǎn)換為開啟或關(guān)閉閥門的力。這些設(shè)備可以使用交流電或直流電。電動閥門執(zhí)行器可能配備電動機(jī)，產(chǎn)生旋轉(zhuǎn)運(yùn)動來轉(zhuǎn)動閥門。這種類型的執(zhí)行器用于需要旋轉(zhuǎn) 90° 才能打開或關(guān)閉的四分之一回轉(zhuǎn)閥門，也稱為四分之一回轉(zhuǎn)執(zhí)行器。球閥和蝶閥執(zhí)行器就屬于四分之一回轉(zhuǎn)執(zhí)行器。
管道和流體控制系統(tǒng)中另一種廣泛使用的電動執(zhí)行器是電磁執(zhí)行器。這些設(shè)備通常與閥門集成在一起，形成一個整體。
Electric actuators convert electrical energy into the force that opens or closes the valve. These devices may run on AC or DC power. Electric valve actuators may feature an electric motor that produces the rotary motion that turns the valve. This type of actuator is used for quarter-turn valves, which require a 90° turn to open or close, and are known as quarter turn actuators. Examples of quarter-turn actuators are ball and butterfly valve actuators.
Another widely used type of electric actuator in piping and fluid control systems is the solenoid actuator. These devices are typically available integrated with the valves, forming a single unit.
氣動執(zhí)行器
Pneumatic actuators
氣動執(zhí)行器利用氣動元件（受控的壓縮空氣系統(tǒng)）來產(chǎn)生操作閥門所需的力。這些執(zhí)行器可能配備一個通過壓縮空氣控制的活塞或隔膜。更常見的活塞式執(zhí)行器包含一個位于腔室內(nèi)的活塞。氣動執(zhí)行器可以是單作用式或雙作用式。單作用執(zhí)行器，通常稱為彈簧復(fù)位執(zhí)行器，在活塞的一側(cè)裝有加載彈簧，使閥門保持在自然位置。要打開或關(guān)閉閥門，需要在活塞的另一側(cè)供給壓縮空氣，氣壓克服彈簧的力。
另一方面，在雙作用執(zhí)行器中，空氣被供給到活塞的兩側(cè)。兩側(cè)之間的壓力差使閥門保持在所需位置。氣動執(zhí)行器通常產(chǎn)生線性運(yùn)動。然而，在諸如蝶閥執(zhí)行器（需要產(chǎn)生旋轉(zhuǎn)運(yùn)動）的執(zhí)行器中，使用運(yùn)動轉(zhuǎn)換機(jī)構(gòu) - 例如齒條和小齒輪以及撥叉機(jī)構(gòu)。
Pneumatic actuator utilizes pneumatics - controlled compressed air systems - to produce the force required to operate a valve. These actuators may feature a piston, or diaphragm, that is controlled via compressed air. The more ubiquitous piston-featuring variety contains a piston housed in a chamber. Pneumatic actuators may be single-acting or double-acting. Single-acting actuators, more commonly known as spring return actuators, feature a loaded spring on one side of the piston that keeps the valve in its natural position. To open or close the valve, pressurized air is supplied on the other side of the piston, and the air pressure overcomes the force of the spring.
On the other hand, in double-acting actuators, the air is supplied to both sides of the piston. The difference in pressure between the two sides keeps the valve in the desired position. Pneumatic actuators typically produce linear motion. However, in actuators such as butterfly valve actuators (which are required to generate rotary motion), motion conversion mechanisms - such as rack and pinion, and scotch yoke mechanisms - are used.
電動執(zhí)行器和氣動執(zhí)行器之間的選擇
Choosing between an electric and a pneumatic actuator
電動和氣動閥門執(zhí)行器在不同應(yīng)用中各有優(yōu)勢。為了選擇適合應(yīng)用的執(zhí)行器，需要分析這些執(zhí)行器的一些因素和特性。下文將探討其中一些因素和特性。
Both electric and pneumatic valve actuators have specific advantages in different applications. To choose the right one for your application, certain factors and characteristics of these actuators have to be analyzed. Some of these factors and characteristics are explored below.
1. 精度/Precision
精度是指需要在部分開啟或關(guān)閉位置操作以允許精確量介質(zhì)流過的閥門。電動和氣動執(zhí)行器均可提供精確的控制。然而，當(dāng)依賴氣動執(zhí)行時，可能需要在氣動操作設(shè)備（例如控制閥）上附加電-氣定位器，以實(shí)現(xiàn)化工生產(chǎn)等應(yīng)用中所需的高精度控制。
Precision is considered for valves that need to operate in partially open or closed positions to allow an exact amount of media to flow through. Both electric and pneumatic actuators provide precise control. However, when relying on pneumatic actuation, the inclusion of an electro-pneumatic positioner may be required as an accessory on a pneumatically operated device such as a control valve to achieve the high precision control necessary in applications such as chemical production.
2. 力的范圍/Force range
氣動執(zhí)行器單位側(cè)向力/扭矩顯著高于電動執(zhí)行器。對于涉及大型閥門或高工作壓力閥門的應(yīng)用，氣動執(zhí)行器是更好的選擇。
Pneumatic actuators provide a significantly higher force/torque per unit side than their electric counterparts. For applications that involve a large valve or a valve with high operating pressure, pneumatic actuators are the better option.
3. 速度/Speed
在防洪等特定應(yīng)用中，執(zhí)行速度是一個至關(guān)重要的考慮因素。與精度一樣，電動執(zhí)行器和氣動執(zhí)行器都可以快速執(zhí)行。然而，氣動執(zhí)行器反應(yīng)更快，占空比更高。此外，氣動執(zhí)行器的運(yùn)行速度可調(diào)。
Speed of actuation is a crucial consideration in specific applications such as flood control. Like with precision, both electric and pneumatic actuators can be fast. However, a pneumatic actuator reacts faster and has high duty cycles. Furthermore, the operating speeds of pneumatic actuators are adjustable.
4. 使用壽命/Lifespan
氣動執(zhí)行器組件較少，因此比電動執(zhí)行器更易于維護(hù)，使用壽命更長。電動執(zhí)行器包含多個部件，可能需要定期維護(hù)。雖然執(zhí)行器單元可能不需要維護(hù)，但其他部件（例如空氣壓縮機(jī)和FRL（過濾器、調(diào)節(jié)器和潤滑器））可能需要更頻繁的維護(hù)。
Pneumatic actuators have fewer components. Therefore, they are easier to maintain and have a longer lifespan than electrical actuators, which have several parts that may require regular maintenance. However, while the actuator unit may not require maintenance, other components such as the air compressor and the FRL (Filter, Regulator, and lubricator) may require more frequent maintenance
5. 成本/Cost
氣動閥門執(zhí)行器的設(shè)計(jì)比電動執(zhí)行器更簡單，因此其成本低于電動執(zhí)行器。然而，如果考慮到配套氣動系統(tǒng)的成本，氣動執(zhí)行系統(tǒng)的總成本就會增加。通過在同一個壓縮空氣供應(yīng)系統(tǒng)中安裝多個執(zhí)行器，可以顯著降低這一成本。
The design of pneumatic valve actuators is more straightforward than that of their electric counterparts, and so these actuators cost less than electric counterparts. However, when the cost of the accompanying pneumatic system is considered, the overall cost of a pneumatic actuation system increases. This cost can be significantly reduced by setting up numerous actuators with the same pressurized air supply system.
6. 故障安全/Fail safe
在執(zhí)行器故障可能造成嚴(yán)重后果的應(yīng)用中，執(zhí)行器需要配備故障安全機(jī)制。在氣動執(zhí)行器中安裝故障安全裝置更簡單、更經(jīng)濟(jì)。彈簧復(fù)位式氣動閥門執(zhí)行器具有固有的故障安全機(jī)制，當(dāng)發(fā)生故障時，彈簧力會自動將閥門返回到其自然位置。
In applications where a failure in the actuator can have severe consequences, the actuator needs to have a fail-safe mechanism. A fail-safe is easier and cheaper to install in pneumatic actuators. Spring return pneumatic valve actuators feature a natural fail-safe mechanism, as the force of the spring will automatically return the valve to its natural position in the case of a failure.
7. 危險(xiǎn)條件/Hazardous conditions
電動執(zhí)行器通常包含精密部件，在危險(xiǎn)條件下可能無法正常工作。此外，這些執(zhí)行器需要獲得多項(xiàng)認(rèn)證才能被認(rèn)定適用于特定環(huán)境。電動執(zhí)行器需要高水平的防護(hù)，以防高溫高壓、灰塵和潮濕。而氣動執(zhí)行器則非常堅(jiān)固，能夠承受比電動執(zhí)行器更高的壓力和溫度。
Electric actuators often feature delicate components that may not function correctly in hazardous conditions. Furthermore, these actuators require numerous certifications in order to be deemed suitable in certain environments. Electric actuators need a high level of protection against high temperatures and pressures, dust, and moisture. On the other hand, pneumatic actuators are quite rugged and can withstand higher pressures and temperatures than their electric counterparts.
結(jié)論
Conclusion
氣動執(zhí)行器和電動執(zhí)行器都是高效且功能強(qiáng)大的自動化設(shè)備，廣泛應(yīng)用于各行各業(yè)。然而，它們各自擁有獨(dú)特的特性，使其在不同應(yīng)用中脫穎而出。為了選擇最適合應(yīng)用的執(zhí)行器，請仔細(xì)考慮上述因素。
Both pneumatic and electric actuators are efficient and highly functional automation devices that are employed across various industries. However, they each possess unique characteristics that make them preferable in different applications. To select the best one for your application, carefully consider the above-listed factors.
聲明：
-文章轉(zhuǎn)載自VALVEMAN，由愛澤工業(yè)翻譯，如有侵權(quán)，請聯(lián)系刪除！
-如有偏頗，歡迎指正！
滬公網(wǎng)安備31011002006738號
