Explosion-proof Type and Principle of Explosion-proof Electric Actuators

電動執(zhí)行器被使用在十分惡劣的、往往有很多易燃易爆氣體混合物的工作環(huán)境中，因此對電動執(zhí)行器的防爆功能有著很高的要求，這樣才能保證電動執(zhí)行器使用的安全性和有效性。本文以中英合資天蝶閥門生產(chǎn)的防爆型電動執(zhí)行器為例，分析如何進行智能型電動執(zhí)行器的防爆結(jié)構(gòu)設(shè)計。

Electric actuators are used in very harsh working conditions,often with a lot of flammable and explosive gas mixture,therefore, the explosion-proof function of the electric actuator is highly required, so as to ensure the safety and effectiveness of the electric actuator.Taking the explosion-proof electric actuator produced by the Sino-British joint venture Tandy Valve as an example, this paper analyzes how to design the explosion-proof structure of the electric actuator.

1、隔爆型電動執(zhí)行器“d”

1. Flameproof electric actuator " d "

一種具有隔爆外殼的電動執(zhí)行器。隔爆外殼能承受已進入外殼內(nèi)部的可燃性混合物內(nèi)部爆炸而不損
壞，并且通過外殼上的任何接合面或結(jié)構(gòu)孔不會引燃一種或多種氣體或蒸氣所形成的外部爆炸性
環(huán)境的電動執(zhí)行器外殼。

An electric actuator with a flameproof enclosure. The flameproof enclosure can withstand an explosion inside a combustible mixture that has entered the outer shell without damaging it bad, and does not ignite the external explosion of one or more gases or vapors through any joint or structural holes on the housing electric actuator housing for the environment.

2、增安型電動執(zhí)行器“e”

2.Increased safety electric actuator "e"

一種對在正常運行條件下不會產(chǎn)生電弧、火花的電動執(zhí)行器采取一些附加措施以提高其安全程度，防止其內(nèi)部盒外部部件可能出現(xiàn)危險溫度、電弧或火花的電動執(zhí)行器。

An electric actuator that does not generate electric arc and spark under normal operating conditions is adopted to take some additional measures to improve its safety, defense
An electric actuator that prevents dangerous temperatures, arcs, or sparks from appearing on external parts of its internal box.

3、本質(zhì)安全型電動執(zhí)行器“i”

3.Intrinsically Safe Type Electric Actuators "i"

本質(zhì)安全通常指某個系統(tǒng)，而不是指某一個設(shè)備。人們通常說一個變送器或傳感器或傳感器是本質(zhì)
安全時，這是一種簡化說法，實際上本質(zhì)安全指變送器或傳感器經(jīng)電纜與關(guān)聯(lián)設(shè)備（安全柵等）組成的本質(zhì)安全系統(tǒng)。

Intrinsic safety usually refers to a system and not to a device. People usually say that a transmitter or sensor or sensor is essential.When secure, this is a simplified term, in fact inherently safe refers to an essential safety system consisting of a transmitter or sensor via cable and associated equipment (security grids, etc.).

本質(zhì)安全電路

Intrinsically safe circuit

本質(zhì)安全電路指在規(guī)定條件（包括正常工作和規(guī)定的條件）下產(chǎn)生的任何火花或任何熱效應(yīng)均不能點燃規(guī)定的爆炸性氣體環(huán)境的電路。

Intrinsic safety circuit means any spark or any thermal effect produced under specified conditions (including normal working and prescribed conditions) shall not ignite the specified explosive gas environment.

本質(zhì)安全設(shè)備

Intrinsic safety equipment

本質(zhì)安全設(shè)備指在其內(nèi)部的所有電路都是本質(zhì)安全電路的電動執(zhí)行器。

Intrinsic safety equipment means that all the internal circuits are essential safety circuits of electric actuators.

關(guān)聯(lián)設(shè)備

Associated equipment

關(guān)聯(lián)設(shè)備指內(nèi)部裝有本質(zhì)安全電路和非本質(zhì)安全電路，且結(jié)構(gòu)使非本質(zhì)安全電路不能對本質(zhì)安全電路產(chǎn)生不利影響的電動執(zhí)行器。關(guān)聯(lián)設(shè)備在危險場所安裝使用時， 應(yīng)加其他形式防爆外殼保護，例如隔爆型、正壓型等；在安全場所安裝使用時，其外殼可選用一般型。在本質(zhì)安全系統(tǒng)中與本質(zhì)安全設(shè)備有電氣連接，接口部分有限壓， 限流環(huán)節(jié)（限制能量）的電動執(zhí)行器可認為是關(guān)聯(lián)電動執(zhí)行器，如齊納安全柵、隔離式安全柵、本質(zhì)安全電源、光電隔離接口電器等。

The device is an electric actuator with intrinsic safety circuit and non-essential safety circuit, and its structure prevents the non-essential safety circuit from having an adverse effect on the intrinsic safety circuit. Other forms of explosion-proof enclosure protection should be added when the associated equipment is installed and used in dangerous places, such as flame-proof type, positive-pressure type, etc. For installation and use in a safe place, the housing may be of the general type. Motor actuators with electrical connections to intrinsic safety equipment, limited voltage in the interface part, and limited current limiter ( limited energy) can be considered to be associated with an electric actuator in an intrinsic safety system, Such as Zener Safety Grid, Isolated Safety Grid, Intrinsic Safety Power Supply, Photoelectric Isolation Interface Electrical Equipment, etc.

4、正壓型電動執(zhí)行器“p”

4.Positive Pressure Type Electric Actuators "p"

一種通過保持內(nèi)部保護氣體的壓力高于周圍爆炸性環(huán)境壓力的措施來達到安全的電動執(zhí)行器。

An electric actuator that achieves safety by keeping the pressure of an internal protective gas above the surrounding explosive ambient pressure.

5、澆封型電動執(zhí)行器“m”

5.Pouring Type Electric Actuators "m"

整臺設(shè)備或其中部分澆封在澆封劑中，在正常運行和認可的過載或認可的故障下均不能點燃周圍的爆炸性混合物的電動執(zhí)行器。

The whole equipment or part of it is put in a pouring agent and cannot ignite the electric actuators of the surrounding explosive mixture under normal operation and in case of an approved overload or failure of approval.