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Pre-assembling at Riedel Filtertechnik’s workshop in Germany. Credit: Riedel Filtertechnik.
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Venturi scrubber for primary at a factory in China. Credit: Riedel Filtertechnik GmbH
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Charcoal dust extraction filter. Credit: Riedel Filtertechnik GmbH
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Central vacuum cleaning system. Credit: Riedel Filtertechnik GmbH
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Stand-alone unit. Credit: Riedel Filtertechnik GmbH
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Airborne dusts, as well as certain aerosols, can pose a substantial explosion risk in factories and ware-houses. While tobacco is not generally considered highly combustible, it’s all a matter of the air-suspended particles’ size. The finer the dust, the higher the danger. As a rule of thumb, it can be said that particulates of any substance that have a diameter of 420μm or smaller are regarded as combustible dusts. While incidents are rare in the tobacco industry, they are not unheard of. Without precautions in place, a single spark or an open flame can set off an astonishingly devastatingly destructive blast.
In the tobacco sector, particulates of that description are often generated in the primary as well as the DIET process, but also may accumulate in cigarette makers, for example. Extremely fine-ground tobacco is used in the production of slurry-type reconstituted tobacco sheets, too. Secondarily, it almost goes without saying that inhaling microscopic tobacco particulates constitutes a serious health risk for workers. A comprehensive dust extraction system therefore is quintessential for tobacco companies, whether they may be suppliers or manufacturers. The practical working principle of tobacco dust extraction is quite similar to that of filtering out other airborne solid particulates such as carbon (coal) or rock dust, thus providers of filtration systems usually cater to a broad range of industries.
ASII: Expert engineering services around Asia
Headquartered in the Philippines, ASII Filtration Systems and Services, Inc. (ASII) has installed comprehensive extraction systems at several tobacco plants around Asia. “In 2018, we installed a dust and vapor filtration project at a Philip Morris International plant’s primary processing facility, as well as a fire prevention system in the DIET area,” the company’s owner and c.e.o., Rene Tacuban, told Tobacco Asia. His engineering company has partnered with Swedish dust and fume extraction systems manufacturer Nederman, as well as German spark detection and fire prevention systems supplier, GreCon, for more than a decade. In this context, Tacuban also hinted at an “ongoing spark and fire prevention installation project currently carried out by us at a Japan Tobacco International facility in the Philippines.”
While the necessary hardware and electronic components are provided by the aforementioned Swedish and German outfits, ASII signs responsible for installing and testing systems on-site. Tacuban stressed the importance of an individual approach. “Every facility is different and requires a customized set-up,” he said. “For that purpose, ASII provides an engineering team capable of handling the system design and delivering a turn-key project based on Nederman and GreCon solutions, including full system integration on location.”
Risk assessment is the primary criteria Proper design is imperative to ensure a safe working environment, too. “Inadequate design paired with poor machinery maintenance leads to quick dust accumulation,” said Tacuban. But, he also pointed out that the requirements may vary from country to country. “What is considered regulation-compliant in one country may not necessarily be handled exactly the same way in another.” However, the size of a processing or manufacturing plant normally are not criteria as per whether a dust filtering system is needed or not. Rather, it’s considerations concerning fire, explosion, and health risk prevention. “That is why our standard procedure al-ways is to conduct a risk assessment in order to better understand [a facility’s] processes before embarking on designing a bespoke solution.”
Riedel Filtertechnik: A century of expertise
Where ASII foremost is a specialized engineering company that designs and installs bespoke systems utilizing its partner firms’ components, Germany-based Riedel Filtertechnik GmbH develops and manufactures its very own proprietary extraction and filtering systems. Having been founded a century ago, the globally-represented outfit is catering to a wide array of industries. “Besides our focus on the tobacco sector, Riedel also is well established in numerous other industries, such as food, auto-motive, chemical, and bulk materials,” confirmed sales director, Frank Puschmann.
In addition to potential tobacco dust ignition in certain settings, Frank Puschmann said that activated carbon needed to be considered as well, as it is very often used in a variety of cigarette filter types. When suspended as dust particulates, activated carbon is in fact considerably more explosive than even the finest tobacco dust. “Dust extraction systems for filter rod making machines and cigarette ripping machines must be equipped with constructive explosion protection if activated carbon is used, as well as activated carbon traps on cigarette makers,” he elaborated.
Incidents are rare, but…
Frank Puschmann pointed out that – at least in the EU – dust extraction systems must be com-pliant with ATEX (Appareils destinés à être utilisés en ATmosphères) regulations to avoid ignition sources. Spark detection and extinguishing systems, as well as explosion protection components, typically also are an integrated part of a dust extraction system. However, Frank Puschmann reiterated that he has never learnt of any tobacco dust explosion incident in the recent past. “These are extremely rare indeed,” he insisted. But, this is perhaps indeed a positive attest to the correct plant design of mod-ern dust extraction and the use of explosion prevention technology when necessary.
Frank Puschmann did recall an explosion in a filter rod-making facility, though. “The blast was triggered by smoldering activated carbon particles entering a dust extraction filter. The particles had been ignited inside the combiner by sparks from the knife-sharpening device. However, the dust extraction filter was equipped with explosion protection measures and the blast luckily didn’t cause any personal injury or property damage.”
It isn’t only potential explosions that can be caused by tobacco dust. It can also accumulate in-side machinery, damaging it over time. Tobacco has a significant silicate content, which can cause me-chanical wear through friction. In the primary, this mainly affects conveyor bearings and other moving or rotating parts, according to Frank Puschmann.
However, cigarette makers can be similarly affected if dust collects unchecked. Effective dust extraction systems takes care of these problems. “A good system reduces mechanical wear considerably by continually removing dust particles, thus helping save costs for spare parts, maintenance or repair,” said Frank Puschmann. To supplement the extraction system, he recommended the additional deployment of central vacuum cleaning systems for machine and floor cleaning.
A solution at hand for everyone
As Rene Tacuban before him, Frank Puschmann likewise insisted that “the requirement of a dust extraction system does not depend on factory size but on the needs of installed machinery and equipment.” However, smaller companies - particularly in developing countries where regulatory compliance occasionally can be quite lax - may not always be able to afford a substantial investment for in-stalling a full-fledged system. But Riedel Filtertechnik has a solution at hand for such scenarios, too. “For companies with relatively small air extraction volume requirements we offer stand-alone units that are installed right next to the machine,” he explained. “These units do not have to be fitted with elaborate extraction pipes and the installation work is less extensive as well, making such a set-up a cost-effective option.”
Frank Puschmann knows what he is talking about. After all, Riedel Filtertechnik has served the international tobacco industry for several decades, having set up extraction systems of any size all around the world. In Asia, the company has fitted factories and processing facilities in Bangladesh, China, India, Indonesia, Japan, Malaysia, Pakistan, the Philippines, Singapore, Taiwan, Thailand, the United Arab Emirates, Vietnam, and numerous other countries.
Modifying Existing Systems
Practically all large and medium-sized processing and manufacturing facilities have had dust extraction systems of one make or another in place for years or even decades. Technology is advancing, of course. So are the laws that may require factories to adhere to more stringent regulations. But, it is not always necessary to completely replace an obsolete extraction system with a brand new one. Depending on the existing system’s technical specifications, an upgrade or refurbishment may be possible.
In fact, Riedel Filtertechnik’s Frank Puschmann claimed that “in recent years the number of dust extraction system modifications and modernizations has increased significantly.” Following a thorough examination and technical assessment of an existing system, the German company can draw up an upgrade or modification plan. “It may be necessary to change the extraction pipe system or replace the fans. Most often, controlling software also must be updated or adapted,” Frank Puschmann said.
He cited as typical examples cases when obsolete cigarette makers are replaced by new models that emit far greater exhaust air volumes, or when production and conversion volumes are increased considerably in a primary processing facility. “As long as our technical assessment determines that existing dust extraction equipment can continue to be used, we’d recommend an appropriate upgrading solution,” Frank Puschmann said. “But if the existing set-up really turns out to be unsalvageable, we’d propose its replacement with a new system.”