Pros and cons of top gas drying methods for gas analyzers

Perma Pure gas dryers are powered by Nafion tubing, which selectively removes water vapor from a gas sample. Because of Nafion polymer’s selectivity for water vapor, a Nafion dryer removes more moisture than other gas drying solutions while protecting analytes in the gas sample.

How It Works:​

A Perma Pure dryer moves water vapor out of the sample gas stream and into a counterflowing purge gas using the partial pressure of water vapor to drive the exchange.

Purge gas should be instrument quality air (-40°C dew point) or nitrogen flowing at two to three times the sample flow rate.​ If no purge gas is available, there are other purge gas configurations that can be used, for example pulling vacuum through the purge path.

While the partial pressure of water in the purge gas is less than in the sample gas, Nafion polymer will selectively transfer water vapor from the sample gas across its membrane and into the purge gas flow to be swept away. At the sample gas outlet, water vapor has been removed from the sample to achieve humidity levels as low as –45 °C dewpoint.​

Pros	Cons
Achieves sub-ambient humidity levels (as low as –45 °C dew point) depending on configuration Keeps analytes, including those that are water-soluble, in the gas sample Provides a consistent humidity level of the output gas No moving parts to wear out and no power required	Requires access to a dry purge gas, such as instrument quality air or use of another purge gas configuration

Also called a Peltier cooler, Peltier chiller, chiller, or thermoelectric chiller, these systems cool a sample gas by chilling it and condensing-out the moisture.

How It Works:​

A gas sample is sent through an impinger, which cooled by a Peltier module using the Peltier effect. Water in the gas sample condenses, and collects at the bottom of the impinger. Water collected in the impinger is drained away, perhaps using a peristaltic pump. This process of condensing-out the water in the sample yields a less humid gas sample at the output.

Pros	Cons
Provide a consistent and known humidity level (+4 C dew point) In CEMS applications, this is the industry standard for gas sample conditioning.	Can’t dry to humidity levels lower than +4 °C dew point If acidic gases are present, such as SOx, NOx, and HCL, +4 °C dew point may not be dry enough to prevent acids from forming and entering the analyzer. Highly water-soluble components in your sample may be lost to water that is condensed out of the sample. Requires periodic cleaning of impingers depending on operation Power required

Also known as a moisture trap, these devices remove existing water droplets from a gas sample. They ‘trap’ the water, but do not remove water vapor from the sample, which may condense at a later point.

How It Works:​

A gas sample is sent into the water trap. ​Any liquid water droplets in the sample will fall out due to gravity and collect at the bottom of the water trap. Before reaching the output, any excess water droplets in the gas stream will be caught by the baffle. ​At the output, the gas contains no liquid water. ​Water in the water trap can be drained by a peristaltic pump, or more commonly, by manually draining it after use.

Pros	Cons
Low-tech and inexpensive No moving parts to wear out and no power required	Can only remove already-condensed liquid  Water-soluble analytes will be lost in the water that is removed from the sample gas  Typically water is drained manually, which increases maintenance

Desiccants are hygroscopic materials that are used to remove moisture. Desiccant gas drying systems are essentially a cartridge filled with desiccant that a wet gas stream is passed through.

A wet gas sample is directed through the desiccant cartridge or desiccant canister. ​Inside, microporous ceramic beads (such as activated alumina, silica gel, molecular sieve, or another ceramic) will trap moisture in their voids, giving a drier sample gas at the output of the desiccant dryer.

While in operation, desiccants become progressively loaded with water, and must be periodically replaced or regenerated by heating the desiccant to evaporate the water.​

Pros	Cons
Low-tech and inexpensive  Achieves sub-ambient humidity levels No moving parts to wear out and no power required	Desiccants non-selectively remove water and other analytes from the gas stream Requires regular replacement of the desiccant over the life of the analyzer  Performance of desiccant degrades over time as it accumulates moisture, leading to inconsistent output humidity levels

This gas drying system dilutes a wet gas sample with dry air, so the gas mixture that reaches the analyzer has less moisture content.

A wet sample gas is diluted by mixing in dry air, such as instrument quality air, to a particular ratio (typically around 25:75, sample gas to instrument air). The analyzer detects the analyte at lower levels but reports the actual value, which is a multiplication of the analyte level detected by the percent volume of sample gas in the mixture that entered the analyzer.​

Pros

Cons

Low maintenance  Can achieve very low, sub-ambient, humidity levels depending on the configuration  No moving parts to wear out

A highly sensitive analyzer is required because the analyte becomes diluted in the gas sample. This requirement makes the configuration expensive. Stability of the dilution ratio is critical to proper calibration, and sometimes difficult to maintain since pressure and temperature of the system can affect the dilution ratio.  Requires access to a dry gas, such as instrument quality air, which may not be available in some operating environments.  Power required

• Can achieve sub-ambient humidity

  Can achieve sub-ambient humidity

• Consistent output humidity

  Consistent output humidity

• Analytes & water soluble analytes retained in sample

  Analytes & water soluble analytes retained in sample

• No moving parts

  No moving parts

• Low maintenance

  Low maintenance

• No power required

  No power required

• No instrument quality air or nitrogen required

  No instrument quality air or nitrogen required

• Total cost of ownership

  Total cost of ownership

Perma Pure MD Series and PD Series Gas Dryers

• Can achieve sub-ambient humidity

• Consistent output humidity

• Analytes & water soluble analytes retained in sample

• No moving parts

• Low maintenance

• No power required

  
  *Required if instrument air or nigtrogen isn't available

• No instrument quality air or nitrogen required

• Total cost of ownership

  $$

Thermoelectric Coolers

• Can achieve sub-ambient humidity

• Consistent output humidity

• Analytes & water soluble analytes retained in sample

• No moving parts

• Low maintenance

• No power required

• No instrument quality air or nitrogen required

• Total cost of ownership

  $$

Water Traps

• Can achieve sub-ambient humidity

• Consistent output humidity

• Analytes & water soluble analytes retained in sample

• No moving parts

• Low maintenance

• No power required

• No instrument quality air or nitrogen required

• Total cost of ownership

  $

Desiccant Dryers

• Can achieve sub-ambient humidity

• Consistent output humidity

• Analytes & water soluble analytes retained in sample

• No moving parts

• Low maintenance

• No power required

• No instrument quality air or nitrogen required

• Total cost of ownership

  $$$

Gas Dilution Systems

• Can achieve sub-ambient humidity

• Consistent output humidity

• Analytes & water soluble analytes retained in sample

  
  * at trace dilutions

• No moving parts

• Low maintenance

• No power required

• No instrument quality air or nitrogen required

• Total cost of ownership

  $$$$

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Polytube Dryer (PD Series​)

Contains multiple Nafion  tubes, and thus is our dryer with the highest drying capacity. Recommended for flow rates up to 40 lpm.

View PD Series  Gas Dryers >

Monotube Dryer (MD Series)

Contains a single Nafion  tube. Recommended for flow rates up to 4 lpm.

View MD Series  Gas Dryers >

All Perma Pure Products

Including all gas dryers, and for CEMS applications, Baldwin Thermoelectric Coolers and sample conditioning systems.

View all Perma Pure products >

The post Pros and cons of top gas drying methods for gas analyzers appeared first on Perma Pure.

医疗环境中存在的细菌

医疗环境中存在的细菌可能不仅难闻。某些类型的细菌还可能对有害患者健康，甚至致命。这就是为何医护人员始终对细菌感染保持高度警惕的原因。

在医疗环境中，呼吸疗法是细菌滋生和感染传播特别需要关注的方面。例如，鼓泡器通常用于呼吸疗法，以在呼吸气体到达患者之前为其增加湿度。然而，鼓泡器可能是细菌污染的主要来源。尽管几乎所有的鼓泡器都使用无菌水/蒸馏水，但当打开起泡器的盖子以注满水时，会引入尘粒和其他环境微粒。当带有细菌的气泡破裂时，它可能引起细菌污染，并可能导致病原体的传播。

医院感染，换言之，即医院获得性感染，由于其危险性，成为人们高度关注的话题。它们可能导致高代价的死亡率和发病率，而这对于我们的医疗系统而言在处理上是个难题。实际上，在医院获得性感染的患者中，医院获得性肺炎是主要的致死因素，占所有医院获得性感染的22％。这就是为何医护人员、医疗器械制造商和联邦机构都致力于降低医疗环境中细菌感染风险的原因。为此，医院也被给予严格审查。

重要的是要知道，周围环境中理想的相对湿度应为40％到60％。若相对湿度过低或过高，病毒感染的风险就会增加。这就是为何在较冷的月份病毒感染会激增的原因。据若干研究结果表明，当相对湿度较低时，小鼠中的感染率会增加。

降低感染风险

疾病控制中心可提供有关如何保持卫生行为以减少污染风险的指南，但要完全消除细菌实属困难。多年来，食品药品监督管理局和医疗器械制造商已召回诸多有细菌感染危险的产品。

控制细菌的途径

控制细菌的一种途径是控制导致细菌滋生的条件。虽然不同类型的细菌需要不同的温度和其他条件才能生长和存活，但它们也需要养分、水分或湿气。若湿气不受控则会促使细菌（包括对人体有害的细菌）滋生。控制湿气可确保其仅在必要时存在，并在不必要时去除，进而可以控制细菌的生长。

控制医疗环境中的湿度

由于湿度不受控可导致意想不到的危险细菌滋生，进而导致接受呼吸治疗的患者死亡和发病，因此，控制湿度至关重要。设计用于呼吸治疗的医疗设备时，找到可靠的方法以控制湿度对减少甚至防止细菌生长大有帮助。进而可促使环境更卫生，患者预后更佳（以及难闻气味更少）。

The post 想要控制细菌滋生？控制湿度！ appeared first on Perma Pure.

As a valued partner to Perma Pure, we would like to take a moment to update you on the actions our organization is taking to ensure the safety of our employees and the continuity of business for our customers.

Employee Health and Safety is our Top Priority
To ensure the health and safety of our people we have taken the following actions:

• Working with our employees on a continual basis in alignment with World Health Organization (WHO).  This includes translating WHO recommendations for employees whose primary language is not English.
• Secure additional cleaning products in support of a healthy, clean work environment.
• Cancel unnecessary travel.

Continuing to Serve our Customers
We recognize that we serve customers whose products make an impact on people and communities all over the world.  In light of the issues caused by COVID-19, we recognize the demand for our technology will increase during this time.  As such, we have taken the following measures:

• Increase safety stock of raw material and specialized tooling to increase speed and capacity.
• Redistribution of team members to meet urgent customer orders and requests.
• Increase staffing levels of critical operational positions.

Please contact a Perma Pure team member with any additional questions or concerns.  You can reach our team directly at CustomerService@permapure.com.

We thank you for your loyalty and we look forward to continuing the great work we do, together.

About Perma Pure LLC
Perma Pure LLC, a Halma company, is a leading manufacturer of high-performance gas conditioning solutions, including dryers, humidifiers, filters, coalescers, specialty scrubbers and complete sample conditioning systems.  Headquartered in Lakewood, NJ, and with service and support centers located in India and China, the Company is the exclusive manufacturer of tubing solutions using Nafion polymer originally developed by DuPont.  With products that deliver best-in-class quality and reliability, Perma Pure is the trusted choice for market leaders in medical, scientific, and environmental monitoring markets.  The Company’s products contribute to the health, safety, and well-being of millions of people around the world.  Perma Pure LLC is ISO certified to 9001:2015, 13485:2016, and is FDA registered. For more information, visit ppchina.wpengine.com.

The post How Perma Pure is Responding to COVID-19 appeared first on Perma Pure.

LAKEWOOD, N.J., Feb. 7, 2020 – Perma Pure LLC, a global leader of gas conditioning solutions for medical, scientific and environmental monitoring applications, today announced that the Company will be exhibiting at MD&M West, Feb. 11-13, in Anaheim, CA.  Visitors to the Perma Pure exhibit, 961, will learn about the Company’s high-performance moisture management solutions for medical applications including capnography, anesthesia monitoring, pulmonary function testing, inhaled gas therapy and more.

MD&M West, now in its 35th year, is where engineers and executives from across the globe converge before going on to change the lives of patients. In addition to the three-day conference covering medtech, 3D printing, and smart manufacturing, the event offers the opportunity to meet suppliers and experts leading the charge to disrupt healthcare.

From decreasing measurement accuracy to increasing patient discomfort, condensation from exhaled breath can have adverse implications. Perma Pure’s Nafion tubing can help can overcome these challenges, improving accuracy by removing moisture interference, retaining breath samples and protect medical monitoring equipment.

About Perma Pure LLC
Perma Pure LLC, a Halma company, is a leading manufacturer of high-performance gas conditioning solutions, including dryers, humidifiers, filters, coalescers, specialty scrubbers and complete sample conditioning systems.  Headquartered in Lakewood, NJ, and with service and support centers located in India and China, the Company is the exclusive manufacturer of tubing solutions using Nafion polymer originally developed by DuPont.  With products that deliver best-in-class quality and reliability, Perma Pure is the trusted choice for market leaders in medical, scientific, and environmental monitoring markets.  The Company’s products contribute to the health, safety, and well-being of millions of people around the world.  Perma Pure LLC is ISO certified to 9001:2015, 13485:2016, and is FDA registered. For more information, visit ppchina.wpengine.com.

The post Perma Pure to Join Medical Equipment Industry Leaders at MD&M West appeared first on Perma Pure.