Summer Workplace Safety & Testing Assumptions

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Summer is here! That means swimming, barbecues, and watermelon. I’ve got to admit, though, I’ll be looking at watermelons a lot differently this season. 

Recently, I came across a Black & Veatch video illustrating the importance of wearing your hardhat. They did it by demonstrating structural bolt falling from 20 and 30 feet onto a watermelon. 

While physics is not my primary background, I thought it would be interesting to share Rhett Allain’s discussion of the video’s science.

Allain notes he’s skeptical of the video’s claim that the one-pound piece will have an impact force of about 2,000 pounds when it collides after falling 20 feet. He notes “it’s really difficult to calculate the impact force for a couple of reasons”: impact force is typically not constant plus impact force depends on the stopping distance. 

He suggests instead that the falling bolt problem is a “perfect situation in which to use the work-energy principle.” He goes on to discuss the many considerations such as the one pound bolt falling its distance, making contact with the watermelon and still moving some distance, and the backward-pushing force on the bolt. He puts it all together in a work-energy equation:

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Then he considers impact force, and tries to determine why the bolt dropped from 30 feet instead of 20 feet smashes through the watermelon. He notes, “Honestly, I have no idea where they are getting their values for this video. (They probably need a good science consultant.)”

Clearly, in the video, the melon breaks. Its structural integrity is disrupted and it falls apart. It’s a gooey mess, and no one wants to think of the same thing happening to their head.

Allain points out also that a hard hat will increase impact force so that “if the bolt hits the hard hat and stops over a shorter distance, this would produce a higher average force.” Yet he also notes, “the hard hat does do one thing that’s very nice. Since the hat has a rigid surface, it distributes the impact force over a larger area, which reduces the impact pressure. Lower pressure means there is less chance that the bolt will penetrate your head.”

Ah, what a relief! Even if you don’t get the physics.

Key Takeaway

Ultimately, this video and Allain’s discussion had me thinking again about the importance of workplace safety. At the same time, Allain’s questioning the science demonstrated reminds me of my consistent warning against assumptions. We need to always be testing our thinking, whether it’s about filtration technology or busting watermelons. Be safe this summer!

Removing Catalyst Fines From Raney Nickel Catalyst Reactions

 

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Whether you call it Raney nickel or Raney mud, this alloy of aluminum and nickel is a reagent common to many organic processes. Currently, most Raney nickel catalyst slurries are clarified with the use of manual plate or nutsche filters, bag filters, or cartridge filters. 

Yet any of these approaches require manual operations for cake discharge and cleaning between batches or campaigns. At the same time, they accrue high labor, maintenance and disposal costs  and  expose operators and the environment to toxic and hazardous solvents, solids and contaminated filter tools.  

BHS developed a more contained, cost-effective approach using batch-operated, pressure-filtration systems candle filters. 

A Candle Filter Primer

A candle filter is a pressure vessel filled with tubular filters called candles. The candle is comprised of a filtrate pipe, a perforated core with supporting tie rods, and a filter sock.

The filtrate pipe runs the length of the candle and ensures high liquid flow, as well as maximum distribution of the gas during cake discharge. The tie rods create an annular space between the filter sock and the perforated core, which helps maintain a low pressure drop during operation and promotes efficient expansion of the filter sock during cake discharge. The filter sock, made of various synthetic materials, is installed over the candle and can remove particles smaller than 1 micron (μm).

As the cake builds during operation, the candle filter’s removal efficiency increases, enabling removal of particles as small as approximately 0.5 μm. During operation, pressure from the reactor forces the slurry into the bottom of the pressure vessel. The solids build up on the outside of the filter sock, while the liquid filtrate flows into the candle through the registers and out of the vessel. This process continues until the maximum pressure drop, design cake thickness, minimum flow, or filtration time is reached. 

For concentrated cake discharge, low-pressure gas enters in the reverse direction through the registers and into the individual candles and expands the filter socks. This process breaks apart the cake, which detaches from the filter sock and falls into the vessel cone. The cake is then discharged as a concentrated slurry. 

Raney Nickel Catalyst with Candle Filters for Slurry Discharge

In this application, the current process after the reactor is gravity separation, hydrocyclones and then followed with cartridges and bag filters.  The specification for the process liquid (diamine and water) is less than 3 ppm catalyst.  This recovery process was inefficient and exposes the operators to the diamine and catalysts creating a safety hazard.  The average particle size is 2 um and amorphous crystals.   

Lab testing and pilot testing was conducted to determine a processing scheme that eliminates solvent exposure, reduces the maintenance and operation requirements of the current scheme and recovers the catalyst to less than 3 ppm.  The final design was a BHS slurry-discharge candle filter with 19 m2 of filtration area. 

Candle Filters for Raney nickel Slurry Discharge

BHS developed this approach working with a client whose process after the reactor included gravity separation, hydrocyclones, then followed with cartridges and bag filters. The specification for the process liquid (diamine and water) was less than 3 ppm catalyst. The average particle size was 2 um and amorphous crystals. Yet, this recovery process was inefficient and exposed operators to the diamine and catalysts, which created a safety hazard.  

BHS conducted lab  and pilot testing to determine a processing scheme that eliminated solvent exposure, reduced maintenance and operation requirements, and recovered the catalyst to less than 3 ppm. The final design was a BHS slurry-discharge candle filter with 19 m2 of filtration area. Learn more about this application in this article.

Inventive Filtration Technologies for Palladium Recovery 

 

Palladium Recovery
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Many times we encounter an “if it ain’t broke don’t fix it,” mentality. Process engineers in particular run up against this constantly. Yet, when it comes to palladium recovery, we’ve seen some strong results from taking an inventive approach to the filtration technologies uses. Currently, in recovering palladium catalysts the slurries are clarified with the use of filter presses, manual plate or nutsche filters, bag filters, or cartridge filters.  

All of these require manual operations for cake discharge and cleaning between batches or campaigns. Other drawback include: 

  • high labor and maintenance costs
  • high disposal costs 
  • exposure of the operators to toxic and hazardous solvents and solids 
  • environmental impact of used and contaminated filter cloth, bag filters and filter cartridges.  

A new approach developed by BHS uses Pressure Plate Filters, which are batch-operated, pressure-filtration systems. Here’s what’s involved.

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Pressure plate filters are comprised of filter plates, contained within a pressure vessel. The vessel contains the circular horizontal filter plates in a plate stack. The slightly sloped plates are conical-shaped metal that support a coarse-mesh backing screen covered with filter cloth. An opening in the center of the plate allows the filtrate to travel between plates and out of the vessel. 

The slurry enters the bottom of the vessel and is pumped upward. The solids build up between the plates, while the liquid flows through the core of the filter plates and exits from the top of the vessel. The cake is then washed and dried. Two unbalance motors vibrate the filter plates to dislodge the cake from the filter cloth so it can be discharged. 

Pressure plate filters are used for filtration of cakes greater than 20 mm thick. They are selected for cakes that are stable horizontally because of the orientation of the plates. 

Palladium Catalyst Filtration, Washing and Drying 

There are many choices of technologies, but we’ve found pressure plate filters provide higher quality filtration. In one application, manual filter presses were used to recover and reuse the palladium catalyst. The filter presses exposed the operators to the process and had inefficient washing and drying. The process had a very short cycle of 4 hours per batch.

However, when the BHS pressure plate filter technology was implemented, the filtration, two-step cake washing, nitrogen blow drying and cake discharge were all completed in less than 4 hours with full containment.  Read the full article to learn more.

Changing it Up with Mixer-Dryer-Reactor Acquisition

 

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Starting off 2019, I talked about push pushing ourselves personally and professionally to embrace change. Well, I’m a man of my word, and I’m proud to announce a big change in filtration technology at BHS-Sonthofen GmbH. We’re looking at 2019 as a year of growth, starting with the acquisition of the internationally active AVA-GmbH technology company.

AVA, based just outside of Munich, Germany, has 25+ years under its belt producing innovative machines and efficient processes for any industry. They tackle mixing, drying, reacting, granulating, sterilizing, evaporating, humidifying, and homogenizing to combine engineering expertise and project management know-how to provide “tailor-made solutions from a single source.”

AVA’s product portfolio is a perfect fit with BHS. Having already cooperated with them on joint projects in the past, we can be sure that our company is only strengthened by this move.

In addressing the sale, Dennis Kemmann, Managing Director of BHS-Sonthofen GmbH was enthusiastic about the opportunity to combine our products to have an “even more comprehensive offering in all of our chemical, pharmaceutical and other markets.” 

Expanding Process Filtration Technology Technologies

BHS’s latest newsletter looks at the pairing in more particular applications. You can read more about selecting AVA Vertical or Horizontal Mixer-Dryers for Batch of or Continuous Operations. The goal is a streamlined approach handling as many processes as possible in one unit to curtail investment and process costs. 

Three of AVA’s multipurpose process machines are presented as possibilities to cover the vast majority of the application spectrum of the powder and granule processing industry:

  • AVA Vertical mixer-dryers for batch operation
  • AVA Horizontal mixer-dryers for batch operation
  • AVA Horizontal mixer-dryers for continuous operation

The newsletter also mentions the AVA test center in Germany, which allows customers to scale up from 15 – 90 liter batch mixer-dryer to full scale batch and continuous operations with full scale-up reports and drying curves issued after testing. The US test center in Charlotte, North Carolina will be completed in 4Q, 2019.

Ultimately, the AVA acquisition is good news for current and prospective clients. This change means more innovative process engineering solutions as well as an expanded team to support our customers. The combination of BHS and AVA systems will provide important process benefits for turnkey projects for our clients worldwide. Let me know what we can do for you!

Novel Filtration Technologies for Pharmaceutical Hydrogenation

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When it comes to removing catalyst fines from pharmaceutical hydrogenation reactions, BHS Filtration has come up with a novel approach.

Currently, most hydrogenation slurries are clarified with the use of manual plate or nutsche filters, bag filters, or cartridge filters. All of these require manual operations for cake discharge and cleaning between batches or campaigns. At the same time, these units suffer from high labor, maintenance and disposal costs as well as the exposure of the operators and the environment to toxic and hazardous solvents and solids, used and contaminated filter cloth, bag filters, and filter cartridges.  

A new approach uses candle filters which are batch-operated, pressure-filtration systems.

Understanding Candle Filters

A candle filter is a pressure vessel filled with tubular filters called candles. The candle is comprised of:

  • filtrate pipe —  runs the length of the candle and ensures high liquid flow, as well as maximum distribution of the gas during cake discharge.
  • perforated core with supporting tie rods —  the tie rods create an annular space between the filter sock and the perforated core, which helps to maintain a low pressure drop during operation and promotes efficient expansion of the filter sock during cake discharge
  • filter sock — installed over the candle, and made of various synthetic materials, the filter sock is capable of removing particles smaller than 1 micron (μm). As the cake builds during operation, the candle filter’s removal efficiency increases, enabling removal of particles as small as approximately 0.5 μm.

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Candle Filter in Action

During operation, pressure from the reactor forces the slurry into the bottom of the pressure vessel. The solids build up on the outside of the filter sock, while the liquid filtrate flows into the candle, through the registers, and out of the vessel. This process continues until the maximum pressure drop, design cake thickness, minimum flow, or filtration time is reached. The cake is then washed to remove impurities and residual mother liquor. Finally, the cake is dried. 

For cake discharge, low-pressure gas enters in the reverse direction through the registers and into the individual candles and expands the filter socks. This process breaks apart the dry cake, which detaches from the filter sock and falls into the vessel cone. The cake can also be discharged as a concentrated slurry. 

Pharmaceutical Hydrogenation Application 

In the pharmaceutical catalytic hydrogenation application, the current process after the reactor is metal bag filters for slurry discharge into manual nutsche “clamshell” filters for vacuum filtration and drying.  The process was time-consuming and required handling of liquids and solids including final “manual dig out” of the filters.  The process solvent was tetrahydrofuran (THF) and ethanol.

Lab testing was conducted to develop a new, one-step process for filtration and drying.  The BHS candle filters with pharma designed candles and cGMP compliance allowed for a revamp of the operation with two filters, one-on/one-off for continuous operation.  Read the full article and let me know what you think!

Application of Separation Techniques & Full Containment

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Process engineers devote their time to finding the appropriate application of separation techniques. There’s need for effective solid-liquid separation, cake washing, and drying steps across industries. In many chemical and pharmaceutical processes, the production operations are further complicated by the nature of the process, especially if the process is air-sensitive or toxic.  

The solid-liquid separation step may be accomplished by pressure, vacuum, or centrifugation in a batch or continuous mode. In this step, further choices need to be made regarding the type of filter media and the thickness of the cake or the cake depth during which the separation occurs. To optimize the production process, I’ve found value in thin-cake (2-25 mm) pressure separation technology for full containment, no residual heel.

Importance of Thin-Cake Filtration

Thin-cake solid-liquid separation can be defined as the formation of a cake in the 2-20 mm thickness range.  In this range, cake compressibility becomes less important in the cake building stage of a separation process.  Compressible cakes can be better handled at thinner cake depths and higher pressures. 

For example, an amorphous crystal that does not centrifuge well or requires long filtration times on Nutsche Filter-Dryers can be filtered at 45 psig with a cake thickness of 2 – 3 mm.  Thin-cakes also lend themselves to more effective washing and drying as there is less of a chance of channeling and the mechanism of “plug-flow” of liquids or gases is enhanced.

Impacting Filtration Performance

There are several parameters that can impact filtration performance:

  • Filtration pressure
  • Temperature
  • Particle size/Particle size distribution
  • Particle shape
  • Cake washing
  • Drying of the filter cake.

BHS’s Autopress technology can conduct filtration, cake washing, pressure and vacuum drying all in a contained environment. Cake discharge is complete. There is no residual liquid or solid heel, which is an important benefit for air-sensitive and toxic products.

Application of filtration techniques
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Understanding Autopress Technology

This fully enclosed filter press, with circular filter plates, allows flow in forward and reverse directions. The filter plates (which can use synthetic or metal media) are contained in pressurized filter housing with a gas-inflated membrane sealing the annular space. Thus, all operations are contained from full vacuum to 150 psig.  

The operation of the AP Filter begins with slurry filling to form thin filter cakes of typically 5 – 25 mm thickness.  Pressure filtration continues operating up to 8 barg.  The cake can then be mechanically compressed to eliminate cracking to ensure maximum washing efficiency in the forward or reverse direction.  Finally, the cake can be pre-dried or fully dried either by vacuum or blowing gas through the cake. Gentle drying without agitation or tumbling is especially important for fragile crystals and thixotropic cakes.  Elastomeric knives sequentially and automatically discharge the circular cakes after which the filter begins a new cycle. 

Read more about this topic in an article I wrote for PharmaChem. My take-away is that with close collaboration between the client and the vendor, we can do the kind of creative problem-solving that applies the separation technique needed to achieve production objectives.

Busyness versus Business and Chemical Engineering Action

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My first blog of 2018 talked about the “speed” of the world and recommended slowing down and reflecting. Well, here’s some free chemical engineering advice as the year draws to a close: It’s important to take the time to review facts and data, analyze decisions, gather inspiration from many sources, and finally proceed with definite actions. Still, you’ll need to be ready to change, as things will come at you at “breakneck speed.”  

In my out-of-the-box way of thinking, I’m going to relate these ideas to the World Cup — Congratulations to France! During the big tournament of the big game in summer 2018, there was a lot of discussion about penalty kicks. 

Bradley Staats discussed them in the Wall Street Journal article “Don’t Simply Dive into Action:  Think.” He looked at various research sources and concluded that “the goalie’s best strategy may be not to move at all.”  At the same time, surveyed goalies have said that they would regret allowing a goal more if they stayed in the center (rather than diving left or right).  This impulse reflects an “action bias.” The idea that doing nothing could be the best strategy for goalies or businesses is seldom discussed.  

Action Bias in Chemical Engineering

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In the world of chemical engineering, when looking at a problem, we are all taught to gather more data, do more testing, investigate more research, get more sources, etc.  And yes, sometimes this is the best strategy when coming across a problem that is new to the plant or to the specific process.  However, there are many different thoughts on this topic from Sherlock Holmes who employs occasional silence and distancing for problem solving to Thomas Watson, longtime CEO of IBM who would tell his salespeople “the trouble with everyone is that we do not think enough…knowledge is the result of thought.”

So, what is the answer?  As we sit at our computers and study the data, we all debate with ourselves whether to take a short walk or brainstorm for 5 minutes.  As the title of the blog states, busyness does not lead to business or to learning.  So, as an engineer, I suggest the brainstorm approach and thinking.  For vendors and sales people too, the tendency is for action.  But, even for sales people, thinking and slowing down to develop the correct approach is critical to success.

My chemical engineering advice is to avoid acting just to show “action.” Instead, take some time to think.  We may have to change Notre Dame Football coach Frank Leahy’s quote to read instead: “when the going gets tough, the tough get thinking.”  Let me know your ideas.

6 Global Trends Driving Filtration and Separation Technology Innovation

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This guest blog by Molly Henry of the American Filtration and Separations Society (AFS), appeared on their site (with my editorial assistance). For those who missed the original, I thought it was information worth sharing again here (in edited form) regarding the global filtration market.

As our population grows and urbanizes, so does our need for clean energy, pure water, increased food supplies, advanced medical care, and improved digital devices and processing power. Filtration and separation suppliers, as an enabling technology to most industries, must continually evolve to increase capacity and improve filtration performance. This blog examines the trends necessitating innovation. 

Population growth will drive demand, which will require increased production and manufacturing efficiency for industrial products, foods and beverages, transportation, and infrastructure. All of which means a greater need for filtration and separation technology.

Rapid urbanization on a global scale requires new and improved infrastructure, including water, power, communications and transportation; all of which require filtration.

Disruptive digital technology changes have dramatically improved computer processing for several decades, and trends call for this to continue. As computer circuits have grown smaller and smaller while increasing in processing power, filtration and separation technologies have also become increasingly more sophisticated.

Natural resource scarcity and climate change will make it increasingly difficult to supply an ever-growing population with clean water. This will drive greater use of desalination technologies. Recycling and reusing of wastewater on a consumer, commercial and industrial scale will become the norm. Filtration and separation technology make all these processes possible.

Transformative advances in healthcare will allow people to live longer, healthier, and more productive lives. A part of this process will be advances in diagnostic and drug therapies, which utilize filtration and separation technologies. At the same time, a focus on a cleaner environment and all natural and pure consumables, will see more industries utilizing filtration and separation rather than chemical technologies to make products safe and pure.

The race to zero emissions and zero discharge for industrial manufacturing, public utilities, automotive and aerospace will be a technology challenge on many fronts. Filtration and separation are among the major enabling technologies for this purify, recycle, and reuse process.

Whatever role you play, keeping an eye on these megatrends will serve you and your constituents well in the quest for long-term growth and value creation in the global filtration market. 

 

Become a Filtration Tech Troubleshooting Expert

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Recently I addressed the too-familiar telephone call that the “filtration system is not working.” When the call comes in — and so seldom during regular business hours —  filtration tech experts have to react quickly to solve the problem.

Now, the question is how do you avoid getting these types of calls in the first place?  Well, you can turn off your cell phone, but maybe isn’t the best idea.  Instead, the better approach is proactive troubleshooting. 

Proactive Filtration Tech Troubleshooting Ideas

As you know, I’m a big fan of Sherlock Holmes. The great sleuth talks about checklists and separating the consequential from the inconsequential facts. This systematic approach works perfectly for troubleshooting — take a systematic approach with a comprehensive set of questions and logic charts.  After all, we all know that most problems, maybe 90% or more, that arise with the filtration system have been experienced before.  

A different approach involves “walking around” or random analysis.  Sherlock and Dr. Watson are also very good at this. They see what’s not there to uncover the facts. This observation approach can help with the unique problems. I’ve written before also about the Japanese approach of “Genchi Genbutsu,” which further explains this option.

Becoming an Expert Troubleshooter

Becoming an Expert Troubleshooter, though, requires developing several “soft” skills over and above your technical expertise and great depth of knowledge in many areas. These characteristics include:

  • Critical thinking: Ask probing questions to everyone at the plant from operators, mechanics, to process and R&D engineers to encourage conversations
  • Excellent communication: Listen to the answers and ask the same questions in a different way or use the answers to formulate different questions and keep an open mind.
  • Empathy: Try to understand potential frustrations.
  • Motivational: Praise everyone who provided you with the answers, ideas, etc. to inspire the plant
  • Ability to teach: Look for teaching moments so problem-solving permeates through the organization.

In the future of work, we’re going to be looking more at talents in addition to expertise. Cultivate your troubleshooting chops. Keep walking around and keep learning. In the meantime, let me know your area of expertise; maybe I can use your skills.

My Thoughts on Filtration Separation Trends and Practices

 

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I recently had the opportunity to share my ideas on filtration separation trends and practices with World of Chemicals magazine. My favorite part may have been the headline, “Aging with perfection in filtration technology.” I like to think they were talking about me — ha ha!

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In the meantime, I thought I’d excerpt some of the thoughts I shared in that interview.

Talking about global trends in the filtration separation equipment market, I noted, as the world’s population grows, there is a need for cleaner energy, improved water & food and advanced health care….Advances in healthcare and pharmaceuticals and nutraceuticals [are also allowing] people to live longer, healthier and more productive lives.

This means, “filtration and separation technology suppliers must continually improve their products to meet these needs. The trends in the filtration market space are two-fold: moving towards continuous filtration (which is more efficient) as well as moving towards finer and finer particle size removal.”

I suspect we’ll see high demand for filtration separation products in “pharmaceuticals with smaller batches, cleanability and multipurpose operations.” Also, “for increased food supply, we see growth in the agrochemical market including fertilizers, pesticides, herbicides and insecticides.” Plus, “cleaner water is driving the specialty chemicals for resins and catalysts.”

As chemical and pharmaceutical manufacturers adapt to more multipurpose facilities, filtration and separation equipment must be cleanable and avoid cross-contamination between products. Batch sizes are also smaller, and we demand for finer filtration and separation to 0.5 microns as well as automatic operation for safety, efficiency etc.

Automation trends & more

Automation technology is one of the most important aspects for customers today. It is critical for filtration and separation products for preventative maintenance, efficient operation, mechanical troubleshooting and process analysis. Applying improved automation technology greatly reduces the energy usage and improves accuracy and precision to the overall process.

Automation also provides for optimum operations, time monitoring systems, report generation and recipe management.

We’re also going to have to incorporate R&D to meet market demands. At BHS, we’re working with clients to combine technologies for full turnkey responsibility to minimize lifecycle costs and reduce operating costs. So, overall, we are focused on innovation, automation, continuous processing, cleanability and overall reliability to 99 percent uptime. We strive to provide complete process solutions with spare parts, service and continually to improve the client’s operation.

This requires testing — of course. “Testing provides the collaboration with the client to provide innovative and cost-effective process solutions.”

At the same time, one big challenge in our market is the need for speed. Speed of innovation is impacting our clients who are developing new processes very quickly using micro-reactors, new chemistry, and new products.

The speed at which the filtration and separation suppliers must operate to meet the clients is even faster. Successful companies must fulfill this “speed” objective without sacrificing any core values of safety, efficiency, quality, and service.