Ductless Fume Hoods have a place in laboratory planning and design.
无管通风柜在实验室设计中占一片天地
一、什么是无管通风柜？
What is a Ductless Fume Hood?
图片
Since inception, in the most basic concept a ductless fume hood is:
A box
With filtration
And a blower for airflow
无管通风柜最基础的概念：
一个盒子
带过滤系统
和一个风机来控制风速
Also Known As: Ductless Self-Filtration Vented Enclosure
也可以叫做：自净型通风柜
A ductless fume hood should be considered as a compliment to traditional total exhaust hoods but never as a full replacement.
无管通风柜应该被视为传统通风柜的合作产品，但是永远不会完全取代有管通风柜
The “Box” should be constructed from materials that meet the customer’s application requirements; ie. chemical resistant, flame resistant or a combination of both when possible.
外壳应该根据不同的客户实验需求选择不同的材质， 比如：防化学腐蚀，防爆，或者两者兼顾。
The filtration package should be designed to adsorb and/or neutralize the target chemicals with a reliable method for saturation detection.
过滤组合应该是设计成吸附或者中和目标化学样本，同时必须 加上可靠的过滤器饱和侦测器。
The airflow should be effective to provide operator protection by properly capturing any generated chemical vapors.
有效的气流要达到通过持续捕捉化学蒸汽或粒子来保护操作者。
二、21世纪实验室无管通风柜的安全解决方案
Ductless Fume Hoods-Engineered Safety Solutions for the 21st Century Laboratory
图片
Ductless fume hoods provide laboratories added flexibility and benefits.
无管通风柜为实验室增加了可移动性以及更多的经济效益
Why go ductless?
为什么要无管？
• Economical & Low Maintenance 经济&低维护成本
• Portable 可移动
• Safe 安全
• Minimal Installation Cost 最小的安装成本
• Environmentally Friendly 对环境的保护
It is important to remember that not ALL ductless fume hood manufacturers build ductless hoods to the same quality standard or follow the same safety standards.
Filtration Monitoring and Gas Detection Methods
过滤器监测和气体监测方法
目前的四种监测方法有
• PID气体分析仪
• 金属氧化物阵列
• 酸阵列
• 比色气体取样管
PID气体分析仪可以读出准确的气体浓度。
比色气体取样管提供过滤器饱和状态以及监测。
酸类监测器可以读出PH浓度，根据设定浓度值来提供警报。
金属氧数组对碳氢氧化物有非常敏感的侦测性。
4、安装成本
Installation Cost
• 无管通风柜只需非常低的安装成本，因为它是运到即用型的。
• 无管通风柜只需拆开包装即可投入使用。
• 无管通风柜应该被制造商校准和测试使用。
• 传统通风柜需要安装风机，管道，组装通风柜整体结构。
5、环境保护
Environmentally Friendly
• 无管通风柜循环使用被过滤后的室内气体
• 有害气体不会被实验室排放至我们的大气中
• 气相键合碳过滤器可以在饱和后被安全的处理掉
• 实验室里其他有害气体也会被过滤器捕捉
Points of evaluation
需要验证的几点：
Material of construction and material compatibility with application
通风柜建造材质应根据实验需求
Access to fume hood area and range of motion offered to operator at point of access
过滤器安装位置保证操作人员可以方便进入和移动
Blower capacity and control to maintain containment
风机控制来维持气体不会外流
Monitoring and indication of filtration bed
监测过滤床装置
Face velocity monitoring and control
面风速实时监测和控制
The type of gas phase filtration is used to capture toxic vapors
气体过滤器可以吸附有毒蒸汽
The method of user indication when adverse events are presented, i.e. filter break through, low airflow, high airflow, high humidity, and high temperature for example
It is important to note that as technology improves so will the capability of a ductless hood.
非常重要的一点， 当科技在不断发展的今天，无管通风柜的技术也在不断发展。
四、为什么要咨询和探讨？
Why Consult and Discuss?
多种因素会影响碳吸附的能力
在蒸汽的实验中，最重要的影响原因有：
• 化学试剂的分子结构
• 浓度
• 竞争吸附
• 相对湿度
• 气压
• 湿度
无管通风柜的过滤级别
Filtration Categories for Ductless Hood
DH I
Non-toxic chemicals, nuisance
无毒害化学物质
DH II
Designed to filter manufacturer approved toxic contaminants up to filter break through only.
被过滤器生产商批准使用有毒害物质，但不能产生过滤器穿透情况
Not designed to provide secondary containment beyond primary filter break through.
在没有二级过滤器的情况下不会发生主过滤器穿透的情况
DH III
Capable of meeting all DH II requirements and equipped with a filtration device designed to filter manufacturer approved toxic contaminants beyond primary filter break through by providing secondary back-up protection.
能够满足所有DH II 要求，化学物质不会穿透主过滤器，同时具备二级过滤器
DH III should be designed to provide a period of time to continue and end an ongoing experiment with its secondary back-up filter system.
Source: Lawrence Berkeley National Laboratory (California-USA)
无管通风柜的运营成本
Cost to Operate A Ductless Hood
Cost will vary by hood size and chemical(s) to be contained:
支出取决于通风柜尺寸以及化学试剂的选择
Example: 4 foot ductless fume hood
举例说明： 4英尺宽的无管通风柜
Chemicals to be contained: Isopropyl Alcohol, Acetone, Acetonitrile, Toluene and Methanol
化学试剂包含： 异丙醇，丙酮，氰化甲烷，甲苯和甲醇
Evaporation: 25 ml or less per day per chemical
蒸发量： 每天每种试剂蒸发25毫升
Cost of Filters Required: US $ 1,750.00
过滤器费用： 1750美金
Expected Life: Annual replacement
预计寿命： 每年更换过滤器
Energy consumption cost: US $ 38.00 annually
能耗使用： 38美元/年
五、总结
Conclusion
Ductless Fume Hoods or Ductless Self-Filtration Vented Enclosures have a place in today’s laboratories. Consultation and Application Assessment will allow for wide acceptance and the safe placement within the laboratory.