除尘系统防爆设计The Explosion-proof design of dust collection system

2018年11月20日November 20, 2018

李盛东 Robert Li唐纳森亚太区IAF产品技术经理Donaldson APAC IAF Product Engineering Manager

目录Agenda• 了解您的气流

Know Your Air Stream

• 除尘器的选项Dust Collection Options

• 基于习惯性与基于性能减灾策略的对比Prescriptive vs Performance Based Mitigation

• 案例研究Case Studies

了解您的气流Know Your Air Stream空气中含有什么物质What chemical agents are in the air stream

- 颗粒和/或气体 Particulate and/or gases- 是否可以循环回到厂房内，应该循环回去吗？Can they be returned to

the facility, and should they? - 不可知的毒性物质或者接触限值？Unknown toxicity or exposure levels

可燃性粉尘测试 Combustible Dust Testing- Kst and Pmax- 最低点火能量 Minimum Ignition Energy (MIE)- 可燃下限 – 气体 Lower Flammable Limit (LFL) – gases- 爆炸下限浓度 –颗粒 Minimum Explosible Concentration (MEC) - particulate

评估气流中的物质含量Evaluate What’s in the Air Stream

除尘器选项Dust Collection Options• 除尘器种类Type of dust collector

• 除尘器安装地点Location of dust collector

• 配置选项Configurable options

除尘器种类Type of Dust Collector• 过滤式除尘器—传统的袋式或者滤筒式 Media Collectors –

traditional baghouse or cartridge• 湿式除尘器—沉淀器 Wet Collectors – precipitators • 机械式除尘器—旋风除尘器Mechanical Collectors – cyclone • 无外壳除尘器 Enclosureless Collectors

安装位置—室内对室外Location – Indoors vs Outdoors

配置选项 -- 灰斗Configurable Options – Hoppers

配置选项 – 进风口Configurable Options – Inlets

配置选项 – 模块单元Configurable Options – Modular Units

减灾选项Mitigation OptionsNFPA 652 4.2.4 – 合规选项 Compliance Options

- 习惯性解决方法Prescriptive methods• 在NFPA 652和特定工业标准的各个章节中有相关的规定Stated in various chapters for

both 652 and industry-specific standards- 基于性能的解决方法Performance-based methods

• 习惯性解决方法的替代方案 Alternative to prescriptive methods• 第三方文件和其他资源支持 Supported by 3rd party documentation and other

resources

• 工厂设施通常会采用基于习惯性和基于性能的解决方法的混合方案Facilities are usually designed by a mixture of both performance-based and prescriptive design methods.

习惯性方法Prescriptive Method• 防爆保护Explosion Protection

- 泄爆（标准和无焰泄爆）Venting (standard and flameless)- 化学抑爆 Chemical suppression- 抗爆 – 对于除尘器来说，一般不可行Containment – typically

not feasible in dust collection- 无外壳除尘器 Enclosureless collectors

• 爆炸阻止 Explosion Prevention- 入口和出口隔离 Inlet and outlet isolation- 灰斗卸灰 Hopper discharge- 在工艺和独立设备之间Between processes or pieces of

equipment- 火花熄灭 Spark abatement

• 防火保护Fire Protection- 水或者二氧化碳 Water or CO2

工艺之间的隔离Isolate Between Processes各种隔离方法Various methods of isolation

- 被动或者主动Passive or active- 机械的或者化学的Mechanical or chemical- 灰斗卸灰（卸灰阀）Hopper discharges (airlocks)

火灾的防护Fire Protection and Prevention

• 保护 Protection- 水或者喷淋系统 Water or sprinkler systems- 二氧化碳系统CO2 systems

• 阻止 Prevention- 进风口和出风口隔断阀 Inlet and outlet dampers- 隔断门 Abort gates- 火花熄灭系统 Spark abatement systems- 火花冷却器 Spark Cooler

基于性能的解决方法Performance Based Methods• 是NFPA中描述的习惯性方法的替代解决方案

An alternative approach to the prescriptive methods described in NFPA

• 参考通用和特定行业标准Referenced in general and industry-specific standards

• 应用和工艺中的合理措施Do what makes sense for the application or process

• 一般需要第三方测试或者其他文件来证明其有效性Typically requires 3rd party testing or other documentation to help validate claims

DFE除尘器DFE Collector当除尘器的排放空气循环进入厂房或者工艺中时， NFPA要求在回风管道上加装隔离装置，以阻止火焰和/或颗粒循环返回When recirculating air from a dust collector back into a building or process, NFPA requires outlet isolation on the return duct to stop flame and/or particulate from entering the area.

唐纳森DFE除尘器 Donaldson’s DFE Collector- 第三方测试表明：在所有测试中，DFE除尘器成功的隔离了爆燃，没有

火焰和火花可以进入干净空气室Third party testing showed that “In all tests, the filters successfully isolated the deflagration and allowed no flame or sparks to pass into the clean air plenum.”

- 在等待权威部门的审核中，这可以认为是基于性能的可以去除回风管道上隔离阀的替代方案

Pending an AHJ’s approval, this could be seen as a performance based alternative to requiring outlet isolation on the return duct.

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案例研究Case Studies

应用：医药粉尘，Kst<200bar-m/s Application: pharmaceutical dust, Kst <200 bar-m/s减灾装置 Mitigation Equipment:• 泄爆片—通过管道导向室外 Explosion vent

on collector – ducted to outside wall• 进风口机械隔离阀 Mechanical inlet isolation • 符合NFPA要求的泄灰阀NFPA rated airlock

on hopper• HEPA高效过滤器 HEPA after filter

应用：复合材料，Kst值 150bar-m/s Application: Composite material, Kst 150 bar-m/s减灾装置 Mitigation Equipment:• 泄爆片 Explosion vent on collector• 进风口被动隔离（照片没有展示）Passive isolation on

inlet (not shown in photos)• 火花探测和熄灭系统Spark detection and extinguishing

system on inlet• 隔断门和回风管道 Abort gate on return duct• 回风管道HEPA高效过滤器HEPA after filters on return duct

应用：超细铝粉 Kst值为大于300bar-m/s Application: Ultra-fine aluminum powder with Kst +300 bar-m/s减灾装置 Mitigation Equipment: • 化学抑爆和泄爆片（供应商设计） Chemical suppression and

explosion vents on the dust collector (design by vendor)• 进风口化学隔离和滑板阀（主动隔离）Chemical isolation and knife

gate (active isolation) on inlet• 符合NFPA要求的卸料阀NFPA rated airlock on hopper

应用：木粉尘 Kst<200bar-m/s Application: Wood dust, Kst <200 bar-m/s减灾装置 Mitigation Equipment: • 泄爆片 Explosion vents on collector• 进风口火花探测和熄灭装置Spark detection and extinguish on inlet• 回风管道上的用于防火的隔断门 Abort gate on return ducting for fire

mitigation

应用：钛钠混合物 Application: titanium and sodium mixture减灾装置 Mitigation Equipment:• 带红外探测的化学抑爆系统Chemical suppression on collector with infrared

sensors• 进风口和出风口化学隔离Chemical isolation on inlet and outlet• HEPA高效过滤器HEPA after filter• CO2热感消防装置+进风口和出风口单向调风阀 CO2 heat trace fire protection

with inlet and outlet back draft dampers

应用：茶叶粉末 KstA<200bar-m/s application: Powdered tea leaves, Kst <200 bar-m/s减灾装置Mitigation Equipment:• 无焰泄爆装置Flameless vent on collector• 进风口被动隔离 Passive isolation on inlet • 符合NFPA要求的泄灰阀NFPA rated airlocks on

hopper discharge• 消防喷淋系统Sprinkler system for fire protection

应用：玻璃纤维符合材料Kst值120bar-m/s Application: fiberglass composite materials, Kst120 bar-m/s减灾装置Mitigation Equipment:• 化学抑爆系统Chemical

suppression on collector• 进风口化学隔离Chemical

isolation on inlet• 进风口机械隔离Passive

mechanical isolation on inlet

• 符合NFPA要求的泄灰阀NFPA compliant airlock on hopper discharge

谢谢!Thanks!