Airvate Blog

  When doing calculations, designing, and/or on-site work, we have to figure out which standard and code (federal, state, local) we will follow.   EPA and Permits EPA Title V Operating Permits (EPA) National Emission Standards for Hazardous Air Pollutants (NESHAP), Rule 6X for metalworking operations (EPA) Method 22: visual determination of fugitive emissions from material sources (EPA) Method 9: Visual determination of the opacity of emissions from stationary sources NAAQS (National Ambient Air Quality Standards)  On-site Measurement OSHA Technical Manual (OTM) Section II: Chapter 3, on-site Measurement (EPA) Method 22: visual determination of fugitive emissions from material sources (EPA) Method 9: Visual determination of the opacity of emissions from stationary sources Airborne Contaminants Cal/OSHA Title 8 Section 5155 - Airborne Contaminants OSHA (CFR, Title 29,1910) and Subpart Z - Toxic and Hazardous Substances OSHA 3348-05: Guidance for the Identification and...

  I happened to see a crushed filter cartridge when on-site. Normally, it is hard to see one, as they are always thrown into a Toter quickly and stealthily before someone notices. Though crushed, it still looks cool.  A crushed filter cartridge (1) A crushed filter cartridge (2)

This blog post consists of 4 sections 1. Brief on the Ferrous Sulfate Process (in a customer’s plant) 2. Introduction about Ferrous Sulfate and its hydrate state 3. Ferrous Sulfate in the product recovery system and problems it caused 4. Workplace exposure limit of Ferrous Sulfate Brief on the Ferrous Sulfate Process The Ferrous Sulfate heptahydrate bulk first goes through a dryer heated by hot air, then is lifted by a basket elevator to a cooling bed cooled by ambient air from the outside of the building. The exhaust airflows from the dryer and the cooling bed go to the same baghouse for product recovery . The old product recovery system was removed after years in duty and replaced, since the old one couldn’t meet the airflow requirement for the process. The old baghouse was made of carbon steel, while the new one was made of stainless steel which is more suitable for this moist and corrosive situation. Introduction about Ferrous Sulfate and its hydrate state Ferrous Sulfate,...

  Three sections in this blog: Push-pull ventilation system and its advantages Disadvantages of general ventilation and side exhaust systems Methods to design a push-pull ventilation system Push-pull ventilation system and its advantages Open surface tanks used in industrial processes often need ventilating to remove harmful pollutants (vapors, fumes or aerosols) from the working environment. One method of removing pollutants is the so-called side push-pull ventilation system, in which a jet of air is blown (or pushed) from one side of the tank and collected (or pulled) by an exhaust hood on the opposite parallel side. This system is particularly useful for large tanks where access requirements preclude the use of an overhead canopy, and the size of the tank makes side (or rim) exhaust systems prohibitively expensive. Most agree that a push-pull ventilation system can yield air savings of up to 50% compared to a side suction only hood. An illustration of a push-pull system for an o...

  Three sections in this blog post: The value of obtaining ventilation test data,  Baseline Test,  Periodic Tests.  Periodic Test on an Industrial Ventilation System When Airvate did air balancing, trouble-shooting, field survey, and whole system evaluation of an industrial ventilation and dust collection system, we always recommended customers to obtain baseline test results after any new system is installed and to do periodic system tests to any existing system. The designer, installer, or their subcontractor should conduct the first, baseline, system test right after a system is installed. The system provider should provide evidence that the system is operating according to its design specifications. Periodic tests should also be made throughout the life of the system to ensure continuing performance, detect problems in the system, and monitor the effects of any changes in ventilation or in production practices. The value of obtaining ventilation test data is...

Three sections in this blog post: There are reasons for "lack of maintenance" Ventilation systems need to be designed to include access for cleaning and preventive maintenance One example of the benefits of easy access for maintenance Airvate engineers have worked with customers for many years and talked with plant management and maintenance guys a lot. We understand their feelings of embarrassment which are hard to mention. There are reasons for "lack of maintenance" Ventilation systems often are installed and then ignored until complaints or obvious problems force attention. This neglect may be due to insufficient knowledge and motivation.  Final users normally don't employ any professional engineer to operate and maintain these dust collection and ventilation systems, especially for small and medium-sized ones as they are "secondary". We hear many times that inadequate or no maintenance caused problems in the systems. I personally believe it is unfa...

  Introduction A damper is a device that adjusts the volume of airflow passing through the outlet, inlet or duct. By proper adjustment of all dampers in a system, a desired distribution of airflows in all the branches can be obtained, while minimizing the total airflow of the system to save energy— this is also termed air balancing. The most common dampers used in industrial ventilation and dust collection systems to balance airflows are slide gate dampers (The slide gate, also called “blast gate or cut-off” damper). In a slide gate damper (see Figure 1 of a straight flat slide gate damper), the slide is inserted perpendicular to the flow. Figure 1 A sample of straight flat slide gate damper As the gate is sliding into the duct, it will add resistance to the airflow and consequently reduce the volume of airflow, while increasing airflows in all other branches. Withdrawing the gate has the reverse effect on that branch and all the others in a system. Interaction between a fan ...