Tracking Environmental Data

Stewart Thompson

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In order to stay compliant with regulations, cleanroom managers need to have accurate data on the status of the facility. This means continual assurances that everything is running as it should and being notified when it’s not. An unintended or unexpected event can cause damage, downtime, or worse if not handled in a timely manner. But how can a manager respond unless they have the appropriate tools to monitor the space and alert them if something is not within spec?

Recently, a company in Nashville, Tenn. that stores pharmaceuticals for several manufacturers addressed this issue. Their facility contains two cleanrooms where technicians work to compound different types of chemotherapy drugs which need to be mixed especially for specific patients based on their individual diagnoses and history.

The chemotherapy cleanrooms each measure about 950 ft² and are housed within a larger warehouse which also includes product storage rooms and research areas. Staff members use full cleanroom suits to enter and exit through the airlocked antechambers, while the cleanrooms are equipped with HEPA filters and blower systems in accordance with USP-797 regulations. Additionally, three laser particle counters are installed in each cleanroom to scan the HEPA filters.

To ensure their cleanrooms’ integrity and document best practices, staff continually log extensive environmental data. Each cleanroom’s temperature needs to be maintained at 70°F with a variance of +/- 2°F and a relative humidity of about 50% depending on the drug or product monitored. Within the cleanrooms, staff also have to ensure the minimum .03 in. water column positive air pressure per facility policy in respect to the anteroom environment to ensure that particulate matter is blown outside. This value is continually measured at a pair of differential pressure points located inside and directly outside each cleanroom.

During the selection process for their monitoring system, the staff wanted to go with a wireless setup to monitor differential pressure, temperature, and relative humidity. Technicians also wanted to avoid complications arising from the extensive wiring necessitated by Ethernet systems. Automated alarm functionality was another major priority for the facility — for example, if pouches of these drugs were torn or spilled. Continuous alarm sampling was also requested to alert staff if the blower system failed or the HEPA filters became blocked from long use, either of which would quickly compromise the cleanrooms and product safety.

While the staff considered system intrusion from unauthorized parties to be unlikely, they were concerned about the possibility of users inadvertently modifying or deleting data, so they knew that their prospective system’s software would need to prevent this.

Equipment for continual monitoring

After a review of product and equipment options, the staff selected a system that addressed their needs. The equipment included four wireless temperature and humidity data loggers, two in each cleanroom, mounted on wall brackets. The data loggers have an external sensor that measures and records both temperature and humidity at a temperature range of 32°F to 131°F, and relative humidity from 10% to 95% RH.

To monitor differential pressure, four wireless voltage data loggers were connected to four commercial pressure transducers at two points just inside and outside the cleanrooms. The 0 to 5V outputs of these sensors were connected to the loggers along with current cables. Meanwhile, installers ran tubes to the inside and outside of each cleanroom to begin wirelessly recording the differential pressure. In the event of an accident, data loggers are housed in water-resistant cases and protected by a rugged design.


_{Delphin Technology’s TopMessage Data Acquisition and Control System}

Two wireless USB stations, one in each cleanroom, were also installed to automatically collect the pressure, temperature, and humidity data from the loggers. The base stations’ integrated repeater mode allows users to configure the devices to function as a daisy-chainable repeater. This extends communication range and eliminates wireless range problems. If necessary, the USB-connected base stations can also connect directly to a PC through their integrated USB ports. Wireless range for the data loggers extends to a distance of up to 100 meters in the unobstructed chambers.

After quick configuration and setup, each logger now automatically records and transmits readings to the wireless base stations over the Internet, and each can also store readings to its 16,000 point memory.

The base stations also include software which is connected to the facility’s network and supports data collection functions including real-time monitoring and scheduled downloads. The software also allows users to print data and create text files, tables, and graphs of the data collected by the remote units.

Users can flexibly set sample rates on the data loggers to measure at frequencies from every second up to every hour for up to 64 units in one group. The data loggers are set to take a reading and perform an alarm check every ten minutes.

Alarms, alerts, and information retrieval

The wireless base stations also send out automated alarm emails. Users have configured warning settings so that whenever any of the environmental data goes outside the limits, email alarms are sent out to all specified addresses. Staff receive immediate alerts on their mobile devices and pagers which greatly decreases response times. Up to 50 addresses can receive these automated alerts.

The wireless base stations transmit all logger data to the manufacturer’s dedicated Internet server for cloud-based retrieval. This service lets users remotely access all current readings and share recorded data from their browsers.

The online service is regularly accessed via smartphone by an onsite worker who periodically checks it for irregularities. Additionally, offsite IT support can also access the data in the event of emergencies or to zero in on problems. The service also prevents accidental alteration or deletion of the data by assigning user IDs.

Data and compliance

The facility’s cleanroom integrity benefits in several key ways following installation of the wireless system. The system’s communication capability spares technicians the trouble of installing wiring or having to travel to gather the readings manually. The wireless data loggers help staff maintain the cleanrooms’ differential pressure, temperature, and relative humidity via continual monitoring and alarming. The data loggers automatically record all these values and then transmit their measurements to the wireless base stations in each cleanroom.

Using the base station to aggregate the data, staff can view and download the real-time numbers anytime from anywhere, and receive an alert when vital parameters suddenly go out of specification, eliminating delays. Meanwhile, the off-site service keeps all the online data secure from alteration by unauthorized users.

Due to faster response times and complete data overview, the facility’s cleanrooms are now fully compliant with USP-797 regulations and the facility has online documentation of its best practices. The warehouse has since expanded from the initial eight data loggers to monitor products in adjacent storage rooms.

Six Steps to Beating the Heat

Thu, 10/10/2013 - 2:37pm

Jim McLaughlin

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Monitoring temperature and other environmental factors is critical for many different kinds of systems, particularly IT systems, where specific temperature and humidity ranges are essential to both hardware functionality and product reliability. The wrong environmental conditions can have a dramatic effect on the performance and reliability of mission critical hardware and software driven devices.

The need to monitor environmental conditions remotely and automatically has continued to increase as today’s infrastructures continue to branch out. The need for on-site supervision of system components is no longer necessary in the majority of instances; and new, advanced environmental solutions have made it easier than ever to remotely monitor with confidence. Products designed for seamless integration with network system devices, and products that have alarm inputs (contact closure), help integrate various IT devices, security products, or network appliances for enterprise-level environmental monitoring.  Remote and automatic monitoring has also become easier with the availability of unified application programming interfaces (API) that allow software components to communicate with each other.

^{Monitoring systems can automatically notify system administrators of an alarm condition when values do not meet user-defined levels.}


Environmental monitoring systems help system operators maintain user-defined conditions such as temperature, airflow, and humidity levels, as well as fan failures and power line changes. They can also help network administrators to more effectively manage their systems with detailed management reports that track environmental trends over time. In the event of a sudden disruption, such as an HVAC outage, environmental monitoring systems can also automatically notify system administrators of an alarm condition via email, TCP/IP messaging, or tunneled alarm relays when values do not meet user-defined levels. In addition, software systems interface with these sensors to provide advanced logging, recording, and video integration for networked systems. Environmental monitoring solutions can also feature sensor probes that are easily affixed in critical equipment locations. These units incorporate USB ports that allow the probes to be placed far from the base units.

As the need for environmental monitoring systems continues to generate discussion across industry forums, so has the selection of systems to choose from. Just like any purchase, you get what you pay for, and although the performance and reliability of any system is not exclusively contingent on price, the cheapest alternatives often fall short of their claims. With that in mind, here are some factors to consider when buying a temperature and humidity monitoring system:

1. Self-contained systems ensure easier implementation and help maintain continuous communications. An environmental monitoring system with a built-in server ensures the delivery of continuous information from probes in the system and the base unit itself which is also subject to environmental conditions. Such systems should be easy to use with no additional requirement for client software or Active X components. Systems with built-in servers should be compatible with major Web browsers and operating systems including Linux and Apple, and should not require any custom software or interfaces for implementation.

2. Choose a system that also monitors itself. An environmental monitoring system should also be environmentally hardened and self-monitoring. Its features should include bi-directional RS232-485 communications, pop-up alerts, alarm notifications, logging, polling, and network management with interactive searches.

3. Systems should be resilient. Systems must be tolerant of power loss, and programming should be maintained and reloaded automatically in the event of a power or communication loss.

4. Environmental probes should be easy to position. Smaller sized probes can be easily located for monitoring individual devices within a rack or overall rack conditions. Probe connections should use standard USB cable and be able to extend up to 200 feet using standard cables.

5. Installation and application flexibility. Environmental monitoring systems should provide seamless third party product integration, for example, by using an API. Products with contact closure outputs should be able to be integrated into the network.

6. Cost effectiveness. Monitoring sensors and systems should be affordable and provide maximum value and dependability.

There is too much at stake to skimp on equipment and systems to monitor temperature and other environmental factors in IT systems or other applications. Choosing feature-rich equipment that provides the greatest installation and application flexibility will provide the fastest ROI, and will ensure continued and dependable functioning of critical systems for years to come.

Contaminants and Purity Classes

Industry standards serve a very important purpose for the end users of compressed air equipment. If the standards are well written, they can help to promote the equipment that they govern, as long as the equipment manufacturers properly apply and promote the standards. One of the most widely used standards in use today in the compressed air industry is ISO8573. It is a multipart standard that seeks to establish a method of classifying the purity of compressed air in part 1, then gives us the tools for measuring and quantifying that purity in parts 2 through 9.
ISO8573 is arranged as follows:

• Part 1: Contaminants and Purity Classes
• Part 2: Test methods for oil aerosol content
• Part 3: Test methods for measurement of humidity
• Part 4: Test methods for solid particle content
• Part 5: Determination of oil vapor and organic solvents content
• Part 6: Determination of content of gaseous contaminants
• Part 7: Test methods for viable microbiological contaminant content
• Part 8: Test methods for solid particle content by mass concentration
• Part 9: Test methods for determining liquid water content

In this article I will focus on Part 1 of ISO 8573, and describe why the standard was developed, how it should be used, and what the future holds for this standard in the compressed air industry. But before we look at Part 1 of ISO8573, we need to take a look at what causes compressed air to be “impure”.
How successfully compressed air stream cleanliness requirements are met, can have a dramatic impact on overall plant operating costs. Excessive contamination shortens the life of components and systems, adversely affects product quality, can result in excessive maintenance costs, and can even create health and safety problems.
Contaminants in the form of solid particulates, oil aerosols and vapor, water aerosols and vapor, and even unwanted gaseous vapors can be introduced from the plant environment, ingested by the compressors, or created by the air compressor and distribution system.
While many compressed air applications require a high degree of purity, all compressed air applications work better if the air is clean and dry. However, when the air leaves a compressor, it is anything but clean and dry.

	Chart taken from ISO8573.1 : 2001

Sources of Contamination

Contaminants in compressed air systems have three possible points of origin. They can come from the air drawn into the compressor, from internal compressor mechanisms, and from the compressed air distribution system. Compressors draw in virtually all particles, vapors, and gases in the air within a six-foot radius of the inlet. Smaller particles, less than 10 microns in size, can be drawn in from a larger radius. The compressor inlet filter is designed to stop larger particles that could cause rapid wear of compressor parts. This design prevents excessively frequent replacements of the air intake filter element, but it does little to protect sensitive applications downstream of the compressor. Most of the airborne particles smaller than 10 microns can enter the compressor. Also, any gases and vapors around the intake will enter the compressor, and become part of the compressed air supply. These include combustion by-products such as carbon dioxide, carbon monoxide, nitrous oxides, or sulfur dioxides.
Another factor affecting air contamination is that during compression to 100 PSI, the air volume is reduced by a factor of seven, meaning seven cubic feet of ambient air becomes one cubic foot of compressed air. The result is an increase in the concentration of airborne particles in the compressed air stream. After compression, some of the most common airborne contaminants include dirt & pollen particles, iron oxide (rust) particles, microorganisms, unburned hydrocarbons, liquid water, water aerosols and water vapor, and oil aerosols and vapor.
Now that we know what the contaminants are made up of, we can take a look at how the ISO standard is used to classify the type and amount of contamination in compressed air.

The Purity Classes

The current version of ISO8573 Part 1 was published in 2001, although it is currently in the process of being revised. Every 5 years ISO standards are reviewed to determine whether they are still timely, accurate, and useful to the industries that they serve. If the Working Group, which is made up of volunteer industry experts, decides that the standard requires no revision, then nothing is done to change the standard, and it retains its current publication date. If the standard is revised, then a new publication date is assigned to it once the revision has completed the required balloting procedure. When referring to an ISO standard, it’s common practice to include the publication date, so you may see Part 1 of this standard referred to as ISO8573.1 : 2001.
There are three categories of contaminants that have been assigned classes in ISO8573.1 : 2001. The first category is solid particulates. The second category is made up of a combination of liquid water and water vapor. The third category is called oil, and it too consists of the sum of the liquid oil (in aerosol or liquid droplet form) and oil vapor. The chart below summarizes the three categories of contaminants, and shows the limits of contamination that are required to differentiate one purity class from another.
The purity classes range from the cleanest, class 0, to the most impure, class 9. Note that not all of the categories have the full range of classes; only the water category does. Also, notice that class 0 does not have any numbers associated with it in any of the categories. In the text of ISO8473.1 : 2001 class 0 is defined by stating “As specified by the equipment user or supplier and more stringent than class 1”. It is very important to understand that class 0 does not imply that there are no contaminants present; it simply means that there are fewer contaminants than in class one.

Solid Particulates

There are eight possible classes for solid particulates, from class 0 to class 7. Class 0 is the most pure, but it is numerically undefined, other than to say that it must be more pure (fewer particles in each size range) than class 1. Classes 0 through 5 are defined by the number of particles in a particular size range, in one cubic meter of compressed air. Measurement methods are described in Part 4 of ISO8573 for classes 0 through 5.
Classes 6 and 7 are used to describe compressed air that is typically too “dirty” to be measured with a particle counter. Instead, mass measurements are used to determine the amount of particulate contamination in the compressed air, according to Part 8 of ISO8573.

Water

There are ten possible classes for water contamination, from class 0 to class 9. Class 0 is the driest, but it is numerically undefined, other than to say that it must be drier (a lower pressure dew point) than class 1. Classes 0 through 6 are defined by the pressure dew point of the compressed air. Pressure dew point is defined as the temperature at which moisture begins to condense in the pipes and storage tanks of a compressed air system while it is operating, and hence, under pressure. Pressure dew point is a useful method of describing the humidity in compressed air because it tells us that we must keep the ambient temperature that surrounds the compressed air distribution system above the pressure dew point in order to prevent liquid water from condensing inside the piping. Pressure dew point measurements are described in Part 3 of ISO8573.
Classes 7 through 9 are used to describe compressed air that contains liquid water. As mentioned, liquid water appears in the distribution piping and storage when the pressure dew point of the compressed air is higher than the temperature of the ambient air, and it means that the compressed air contains as much water vapor as is possible for it to contain. This condition is usually called “saturated” air. When liquid water is present in the compressed air line, we use the methods described in ISO8573 Part 9 to measure the amount.

Oil

There are only five classes for oil in the standard, but they describe a wide range of concentrations. Again, class 0 is the most pure, and according to the standard, it describes compressed air that must be more pure than class 1. Classes 1 through 4 cover the range from less than 0.01 mg of oil content per cubic meter of compressed air to less than 5 mg per cubic meter.
It is very important to understand that the oil classes can only be determined by adding the contribution from a.) any liquid oil in the compressed air, b.) the oil aerosols in the compressed air (typically generated by the reciprocal or rotary motion in lubricated compressors), and c.) oil vapors that can come from the oil in the compressor crankcase or sump, or from ingestion at the inlet of the compressor. Liquid oil and oil aerosols are measured using the techniques in ISO8573 Part 2, and the oil vapors are measured using the methods in Part 5.

Reporting the Purity Classes

According to the standard, the purity classes of compressed air shall be expressed by stating the standard reference number and part, the date of issue, and the three class designations in a specific order: Particulate Water Oil. For example, if the compressed air purity of an audited air system was expressed as ISO8573.1 : 2001 1 2 1, the Particulate Class would be 1, the Water Class would be 2, and the Oil Class would be 1. If the class for a particular category is omitted, then a hyphen is used in its place.
Many manufacturers of equipment powered by compressed air are now using this standard to express the purity level of the compressed air supply required in order to keep their tool or process running smoothly and in control. Air tool manufacturers and paint and powder coating suppliers are just two examples of entities that are using ISO8573 to improve their customer’s satisfaction with their products.

Talking Dewpoint

  Please define dewpoint.
Dewpoint is defined as the temperature to which a gas (e.g. air) must be cooled, at constant pressure, for water vapor to begin to condense to liquid water. In other words, when the dewpoint temperature has been reached, the gas is fully saturated with water vapor. The term “pressure dewpoint” refers to the dewpoint temperature of a gas at pressures higher than atmospheric pressure. When addressing dewpoint in pressurized compressed air, the correct terminology is actually “pressure dewpoint,” but this is often shortened to “dewpoint” in common usage.

Why is dewpoint so important in pharmaceutical applications?
Compressed air may be used for a number of applications in the pharmaceutical industry, such as raw material transport, processing equipment, pneumatic power sources, and cleaning. The importance of knowing the dewpoint in a compressed air line may be critical for some applications but less relevant for others. For example, bulk solid and powder conveyers used for moving product rely on sufficiently dried and filtered air in order to perform their function properly and prevent product contamination. Continuous monitoring and control of dewpoint is often a requirement for instrument air, drying processes, packaging, and actuating process control valves. The risks associated with letting dewpoint levels go unchecked can include equipment failure, condensation in process lines and on finished product, and the potential for bacterial formation.

Why is dewpoint so important in laboratory environments?
Laboratory environments are often designed to maintain a controlled atmosphere in order to eliminate airborne contaminants and any sources of error that may interfere with testing. Dewpoint can be an important parameter to control. This is usually accomplished through the environmental control system and has little to do with compressed air. Some lab equipment, such as glove boxes, may require their feed gas to meet an established dewpoint level in order to maintain the inert atmosphere of the chamber.

How is dewpoint measured and monitored in most facilities?
When discussing a typical facility’s compressed air system, it’s helpful to divide the entire network into two separate subsystems: the supply side and demand side. The supply side consists of the compressors and air treatment equipment up to the flow/pressure controller. The demand side consists of the distribution and storage systems or everything after the flow/pressure controller. On the supply side, dewpoint transmitters providing analog signals can be built into the dryer control system or can be installed in-line before or after the receiver tank. On the demand side, fixed mount instruments providing a local display, alarm relays and datalogging capability are quite common throughout the distribution network and before critical end-use applications to give operators and plant personnel a quick assessment of dewpoint conditions at specific points in the system. This helps ensure that the dewpoint level of the air being produced at the dryers is maintained through the entire facility and to the end use points. Portable devices are an excellent tool for verifying dryer performance, conducting quality audits, and checking the calibration of fixed mount instruments.

How is dewpoint measured by refrigerated air dryers?
Refrigerated dryers operate by using a refrigerant to cool the supply air with heat exchangers (usually to between 35ºF to 40ºF) and condense out water vapor for removal by a moisture separator and drain. Due to their relatively low initial cost, long term reliability and minimal maintenance requirements, refrigerated dryers often do not integrate a dewpoint transmitter into their design for monitoring or control purposes.

How is dewpoint measured by desiccant air dryers?
Desiccant air dryers can benefit from a dewpoint sensor for monitoring dryer performance, controlling desiccant tower regeneration, or both. Most regenerative desiccant type dryers (heated or heatless) produce a dewpoint of around -40ºC/ºF. Installing a dewpoint instrument with a display or with built in alarm relays to measure the exit air from the dryer is a smart way to ensure good dryer performance. However dryer efficiency can be significantly improved by using a dewpoint device to control the regeneration cycle – known as Dewpoint Demand Switching (DDS). Desiccant dryers operate using two separate towers containing desiccant – one tower is always in operation while the other tower is being regenerated or purged using a portion of the dried exiting air. Some towers switch based on a timer, regardless of whether the desiccant has been fully saturated. By integrating a dewpoint sensor with the dryer control system, the towers will not switch until the dewpoint transmitter senses a degrading dewpoint temperature, thus ensuring full utilization of each desiccant tower and minimizing wasted purge air.

How is dewpoint measured in point-of-use applications?
For point-of-use dewpoint measurements, generally there are two options available, direct in-line insertion or sample extraction. Each method offers advantages and disadvantages that should be considered carefully. Direct insertion involves installing the probe through a threaded connection or “T” in the line. The benefits of this approach are ease of installation with no accessories required and no venting or loss of the compressed air. Line pressure fluctuations and sensor removal however can present drawbacks. The best installation for a dewpoint instrument isolates the sensor from the main line using a stainless steel sample line and sample cell. This setup allows for “valving off” from the main line and the ability to regulate the pressure, which has a considerable affect on the dewpoint reading. Easy installation and removal of the sensor can also be an important advantage.

What are the different prevalent technologies used to measure dewpoint?
With the vast number of different hygrometer technologies currently available on the market for measuring a wide range of dewpoints suited to different applications and industries, it would be difficult to cover all of them here in any detail. I’ll limit the scope of the discussion to briefly address only the most common sensor types used in compressed air measurement.
Condensation hygrometers, often called “chilled mirrors” operate by cooling a surface in a controlled manner until condensation begins to form; this temperature is recorded as the dewpoint temperature of the air. The most common detection method for determining when liquid water has begun to form is optical reflectance, which uses a light source to measure the amount of reflected light from the surface. These devices are well known for their high accuracy (usually +/-0.2ºC dewpoint) but generally require more maintenance to keep their reflective surface clean. They become prohibitively expensive for measuring very low dewpoint temperatures.
Aluminum oxide, silicon oxide, and various other capacitive sensors share some common traits. In all cases, a capacitor is formed between two electrodes with a hygroscopic material serving as the dielectric of the capacitor. The hygroscopic material adsorbs or desorbs water vapor in proportion to the amount of water vapor surrounding the sensor. This changes the dielectric constant of the material and therefore the capacitance of the sensor. The choice of dielectric materials is critical to the performance of the sensor. Aluminum oxide is sensitive to very low dewpoints, but peforms less well in atmospheric humidity levels. These sensors can be economical for low dewpoints when compared to chilled mirrors.
Thin film polymer capacitive sensors operate on the same principle as aluminum oxide sensors but use polymers instead of metallic oxides as the dielectric material. Many polymer sensors are optimized for use in atmospheric levels of humidity and are not suitable for the measurement of gases with dewpoint temperatures lower than -20°C. However, some polymer sensors are designed for low dewpoint measurement, and they typically distinguish themselves by implementing active, automatic self-calibration schemes to monitor and adjust the performance of the sensor. These sensors are cost competitive with aluminum oxide devices and offer the benefit of enhanced long term stability.

What does Vaisala recommend for measurement and monitoring of dewpoint?
When selecting a dewpoint instrument for a particular application, it’s important to consider the following about the installation:

• What is the expected dewpoint level at the intended measurement location?

• What is the pressure range?

• What is the temperature range?

• Will the probe be installed directly in the line or will a sample line be used for external measurement?

• Should the instrument be portable or fixed mount?

• What type of signal output is desired – local display, analog, serial communication?

• What other functionality is of interest – power supply, datalogging, alarm relays?

With this information specified, the field of dewpoint instruments that fit these criteria will be significantly reduced.

A Pharmaceutical Compressed Air System Audit

By Mike Nagy

A. Introduction

This West Coast pharmaceutical facility has a very clean and organized compressed air system. All equipments is in good working order in the compressor room. The compressor room itself is very clean and well ventilated. The management requested a compressed air system audit for two reasons:

1. Production problems and downtime resulting from the presence of moisture in the compressed air lines. The compressor room dryers were functioning properly so how could this happen?
2. Awareness of the high cost of compressed air and a desire to find ways to reduce compressed air demand.

This article will describe the actions taken to address these two issues. The facility operates “24/7” so we have 8,760 operational hours per year. The average electrical rate at this facility is $0.12 kW/h. The power cost formula used is based upon the facility’s current operating conditions of 3.89 CFM/BHP and 95% average motor efficiency.

Power Cost = (BHP *0.746 * 8,760 hours x $0.12 per kW/h) / Avg. Motor Efficiency (95%)

The focus of this audit is on the “Demand Side” with the very top priority being to identify the root cause of the presence of moisture in the compressed air lines.

B. Compressor Room Review

The Compressor Room is extremely clean and well ventilated. There are two rotary screw compressors which are oil lubricated and air-cooled. The air is dried by two parallel refrigerated air dryers. The air then goes into a common header and flows into a 1,040 gallon air storage tank. The air then flows into a Intermediate Flow Controller. From here the compressed air leaves the compressor room and enters the facility. The average CFM per BHP between the two air compressors is 3.80 CFM per BHP.

Upon entering the compressor room we noted an audible air leak in Compressor #2. We found the leak to be coming from the air end and recommended that the air compressor service provider be contacted immediately. Both air compressors are operating via modulation control. Compressor #2 acts as the base load machine while Compressor #1 is the back-up machine when pressure falls to a predetermined set point.

The two refrigerated air dryers are in good working condition and functioning properly. They are designed to produce a dewpoint range between 33 F and 39 F at a maximum flow of 330 CFM at 100 psi. We took dewpoint measurements at the compressor room outlet (for one week) and found that the average dewpoint achieved was 36 F. This correct dryer performance is what has the facility bewildered by the presence of water in the compressed air lines in the factory. It is worth noting that the dryers are not capable of drying the full air output capacity of the air compressors if factory demand should increase. The dryers have integrated 1 micron particulate filters. We recommend that the facility install a 0.01 ppm oil coalescing filter to protect against oil contamination downstream.

The 1040 gallon air storage tank is adequate for the air demand in the facility. During production we recorded an average air flow of 307.30 CFM which means the tank is providing 3.38 gallons of storage per 1 CFM of air storage. The tank is also piped properly (after the air dryer) with air entering the bottom of the tank and exiting the top – providing more surface area for moisture to be separated and fall to the bottom of the tank.

C. Solving the Problems with Moisture

It was initially reported that the plant was “having problems resulting from an excess of water in the compressed airlines”, with the primary area of concern being the small cylinders in the plant. As a standard part of our audit procedure we took dewpoint readings. These test showed a refrigerated drying system according to its specifications. The data depicted below shows a very steady dewpoint with less than half a degree fluctuation over a ten minute time span. The 36 °F average dewpoint is well within the expected range of performance for these dryers.

As a result of the ongoing condensation issues, the factory had taken some actions in hopes of remediating the problem. The solution the plant put into place was to install water separators on each line and open the drains on Filter-Regulator-Lubricators (FRL’s) throughout the plant. We found a total of 18 FRL units with the drains open, exhausting approximately 2 CFM each worth of compressed air, totaling 36 CFM worth of compressed air. The problem with this is that the only thing exhausting through the drains was compressed air, thereby decreasing plant pressure at the same time.

Moisture in Pneumatic Cylinders Created Production Down-Time

Adiabatic Expansion

Through further investigation we found the root of the problem. When air is discharged from the piping between the cylinder and the valve, the temperature of the air drops due to adiabatic expansion. . If the atmospheric dewpoint of the supply air is T1, and the temperature of the air T2 after adiabatic expansion falls below this value (T1

The Solution to Moisture Problems in Pneumatic Cylinders

There is a very effective solution to this problem, the installation of quick-exhaust valves directly onto the cylinders. These will allow for the cylinder to fully exhaust on every cycle, thereby eliminating condensation build up and save the cylinders. Along with saving the cylinders in the plant, there is no need to keep the drains of the FRL’s opened in the plant. Leaving the drains opened is actually creating a larger pressure drop throughout the plant, and wasting 36 CFM of compressed air.

Understanding what is happening with the pneumatic cylinders was the key to solving this problem. The facility had been considering installing desiccant air dryers. This would have been a significant capital expense and would not have solved the problem. We were able to identify the adiabatic expansion occurring between the cylinder and the valve. The solution deployed of quick-exhaust valve was a minor expense and achieved with little effort.

Quick Exhaust Valves Solved the Problems with Moisture

D. Demand Side Audit

Aside from solving the downstream moisture problem, our audit reviewed pneumatic circuitry in the facility and also included a compressed air leak audit. Below is a brief summary of some of the opportunities discovered and solved. The end result was that air demand was reduced by 186 CFM. This reduced the plant compressed air demand from an average of 307 CFM to an average of 121 CFM.

The Five Label-Aire Machines

We took note of five Label-Aire machines in the factory. These units were constantly being pressurized even when not being used. We conducted a point-of-use test on these machines and found that each machine consumed an average of 4.2 CFM even when not in use. We only sampled a fragment of time so we are not sure of what percentage of the time the machines are idled but plant personnel tell us that it is a significant percentage of time.

The solution here is to keep the Label-Aire machines from consuming air when idled. This is easily achieved by the installation of two-positioned solenoid valves. The solenoid of these valves will effectively actuate this application only when the product is present. The solenoid of these two-positioned valves can be actuated via several applications such as relay sensors and electronic signals. The table below shows the savings opportunity.

Label-Aire Machines Air Consumption Costs When Idle

The Ten Blow Guns

There are ten blow guns at the facility which use inefficient nozzles. This can be costly in the long run due to the decreased impact pressure and increased waste of compressed air. We recommend using high-efficiency nozzles, which can reduce air consumption by 50-75% while increasing the impact pressure at the work surface. These high-efficiency nozzles utilize the Venturi effect to gain efficiencies.

High Efficiency Nozzles on Blow Guns

The Cutter Machine Causes Plant Over-pressurization

The cutter machine is causing the entire plant to run at 100 psig because it requires 95 psig. We conducted a point-of-use test on this machine to verify its’ air usage. The machine was operating between 85 and 90 psig when we started the test. Actual pressure changed over time from 71 psig to 104 psig with 90 being the average. Air flow went from 20 cfm to 10.4 cfm with 4.3 cfm being the average. The cutter was actuating twice a minute, in one minute and 15 second cycles with an intermitten down period of approximately two and one-half minutes.

Due to the intermittent demand of this application, we are recommending the use of a pneumatic booster coupled with a air receiver. This will allow us to reduce the air pressure across the entire facility.

Air Leaks

Leak locations in % at the facility

We have identified and tagged 28 compressed air leaks in the facility. They account for 120 CFM equating to 39% of the plants’ average air flow of 307 CFM. Leaks were found on the airend of one air compressor, and plant-wide on FRL’s, fittings, gauges, and pneumatic tubing.

It is important to have a leak remediation campaign in place to keep leaks from consuming unnecessary compressed air. A proactive approach to leak detection should include all individuals within the plant and the education of machine operators on the cost of leaks.

Machine operators could then combat leaks as they develop by immediately tagging them and notifying maintenance. This approach to leak remediation is perfect for leaks that can be easily felt and heard. Some leaks cannot, unfortunately, be detected by the human ear. We utilize ultrasonic leak detectors to find leaks that are out of range and hard to hear or feel.

E. Capture the Savings

Air Leak on FRL

Multiple Holes/Leaks in Tubing

Air Leak on Hose/Fitting Connect

The demand side audit made it possible for us to reduce average air demand from 307 CFM to 121 CFM. We fixed leaks (120 cfm), closed open drain valves (36 cfm), and will reduce over-all plant pressure (30 cfm). We now need to look at how the compressors are operating and if they controls are set to capitalize on the new compressed air demand profile.

The “Before” situation was this to produce 307.3 cfm:

1. Compressor #1 ran 100% loaded in modulation mode. At 100% power it had 90 BHP which equated to $74,292 in annual costs of operation.
2. Compressor #2 ran 20% loaded in modulation mode. At 78% of power it consumed 67.3 BHP equating to $11,106 in annual energy costs of operation.
3. Total annual energy cost of operation was $85,398

The “After” situation was this to produce 121.3 cfm:

1. Compressor #1 was placed on standby for emergency situations. $0 energy cost.
2. Compressor #2 was capable of having its’ controls modified to Load/No-Load. We ran the machine 37% loaded to meet the demand. At 55% of Power it had 47.45 BHP equating to $39,168 in annual energy costs of operation.
3. Total new annual energy cost of operation was $39,168

The new annual energy costs to run the air compressors represents a savings of $46,230 per year.

Conclusion

Understanding pneumatics is core to conducting a strong demand side audit. Pneumatic circuits were where the audit was able to discover the dewpoint problem and the opportunities to reduce air consumption and pressure. Understanding air compressors and air compressor controls then allowed the installations’ energy costs to be reduced as a result of the demand side improvements.

Air Quality in the Pharmaceutical Industry

By Chris Kelsey

The United States accounts for roughly half of the global pharmaceutical market. This certainly keeps the Food and Drug Administration (FDA) busy in its oversight of pharmaceutical safety and effectiveness, including with the production processes. As the pharmaceutical industry has grown, so too has its utilization of compressed air for breathing air, operation of equipment and instrument air.
The FDA has taken notice, of course, and the quality of the air being used is a concern; and, rightly so, no standard has been issued for the use of compressed air in production.
“A one-size-fits-all standard won’t work here,” says Dr. Ed Golla, Laboratory Director for Austin, Texas-based TRI Air Testing. “Everyone is doing something a little different.”
While this leaves pharmaceutical companies a somewhat in the dark as to how to vet and confirm the quality of air being used, it does not mean companies need to find the tightest standard possible. Each facility will have unique needs, and the standard applied should best serve these needs.

UNDERSTANDING YOUR FACILITY

In the absence of specified standards governing compressed air quality testing in the manufacturing process or production of pharmaceutical, medical device, and food applications, it is often best to use composite, site-specific testing programs. This may be the most assured way to produce valid, repeatable testing results that will reinforce your site’s quality. Direct Product Contact, Indirect Product Contact, USP and ISO 8573 air standards are common sources from which to draw. A routine testing schedule for your compressed air quality program should provide the appropriate verification and compliance each facility will need for OSHA, FDA and cGMP.
It is imperative that you understand the real needs of each site. You do not need to expend the time and money to establish a quality of air that you don’t actually need. “Clean room” air in a non-clean room air operation, for example, is unnecessary. Specifying air to that level requires expensive equipment to clean and maintain it.
If you bring clean room-level air into a non-clean room environment the quality of the clean air is decreased to the level of the room environment. You’ve brought a small amount of clean air into a larger volume of air at a lower level.
“What they really need to do,” says Dr. Golla, “is first look at the quality of air as it is now--as you’ve been using it for the last 10 or 15 years. Identify that quality and base your spec on the quality of air you have input from the engineers involved in the actual process you’re using.”

Greater operational efficiency in air management and cost control can be found in understanding the true air needs in each area of your facility rather than using a single approach for the whole facility.

TRI Air Testing works with many pharmaceutical companies in helping them assess and identify the right air quality tests for compliance, operational efficiency, and safety. TRI sends out its testing equipment along with appropriate sampling media. Clients return the samples for analysis and reports are available within 24 hours.
“The depth and stringency of ISO 8573 may be perfectly applicable to an operation’s clean room particulate control,” says Dr. Golla, “but it isn’t right for all applications.”
Facilities with clean room needs, such as those handling implantable devises (e.g., knee and hip joints, defibrillators and pacemakers) cannot have particulate matter on their surface and affecting the safety of product. These facilities must utilize a spec that ensures a heightened level of particle control.
“You can’t use a spec allowing 5 mg per cubic meter or 1 mg per cubic meter or even a 0.1 mg per cubic meter,” says Dr. Golla. “You need information about the individual particle sizes and counts. With implantable devises once you clean the surface and blow it with compressed air you don’t want to leave particles on it.”
The ISO 8573 spec Class 1 or Class 2 requirements may be ideal here.
But for operations that might be using compressed air to blow out bottles before putting in tablets or simply running a piece of machinery, that most stringent air standard may be excessive. It may lead to greater operational expense or present the facility with a test that is difficult, if not impossible to pass—and all on a process that does not actually need that high of a quality of air.
“If they are concerned about particles, but do not necessarily need something like 8573 Class 1 or Class 2,” says Dr. Golla, “they can use a point-of-use filter.”
If only 1% of a facility, for example, uses a very high-quality air for a specific application, but the general air use in the rest of the facility does not need that quality of air, a point-of-use filter may be the right solution and help achieve greater operational efficiency.
One recommendation: engage the production engineers who are most familiar with the air quality needs. Ask them if there is anything that shouldn’t be in the air. Does it need to be filtered to a finer level? Does the air need to be moist? Or does it need to be dry?
Understanding the real impact of air quality on the specific zone of work, the people conducting the work, and the product being produced or serviced will go a long way towards guaranteeing compliance, levels of safety and the quality the FDA and other regulatory entities want to see.

THE CHALLENGE OF MOISTURE

Identifying a proper moisture spec is not easy. Many facilities just use refrigerated air. They cool the air to remove water; then, they bring it back to room temperature so the humidity is relatively low and you won’t get water formation and bacteria growth.
“That’s probably what you need in 90% or more of the operations,” Dr. Golla says, “yet, we put out a guideline to say there ought to be at least a -10°F for indirect product contact and -50°F or so for direct product contact. I think we put a pretty big asterisk on that to recognize that this one may or may not apply.”
Certain products will be destroyed by -50°F degree dew point air. It will desiccate and deactivate them. For other products, the moisture could react with the material and cause problems, so you might need extremely dry air.
Just as ISO 8573’s most stringent requirement classes are not right for all particulate testing of compressed air, there is no single approach to dew point and moisture management.

Air Filtration in the Pharmaceutical Industry, Cleanroom Filtration

The manufacture of pharmaceutical, bio-pharmaceutical and medicinal products is unique from many other manufacturing processes for a number of reasons.  The most important is that these products are utilized for the health and well being of living organisms, including humans.  Because of this, the design of the manufacturing area of these facilities is required to follow Good Manufacturing Practice (GMP).
The US Food and Drug Administration (FDA) has published Federal Regulation 21 CFR Part 820, Quality System Regulation.  This regulation follows ISO 9000.  More specific to the clean areas and cleanrooms of interest are the standards and drafts under ISO 14644.   A good overview of these standards is available on the IEST web site.  Similarly, European Standards provide European Nations with guidelines for GMPs.
Why do these GMPs matter with regard to air filtration in pharmaceutical, bio-pharmaceutical, and medicinal products manufacturing processes?  Because GMPs require that the quality of these products be assured, including the control of product contamination during manufacturing and packaging.  Generally speaking, the control of contamination is most critical for injectable or parenteral preparations as compared with topically applied or orally ingested preparations.  Eye drops, which can be considered a topically applied preparation, are an exception to this rule as they eye is quit susceptible to infection.