Air Pollution Control Innovations

Wet Scrubber Basics

Posted by Andy Bartocci on Tue, Sep 10, 2019 @ 12:02 PM

 

As an equipment supplier of custom engineered wet scrubber equipment, Envitech frequently provides lunch and learns (L&L’s) to engineering companies to help educate engineers about the basics of available technology.

Figure 1 below is a summary chart of predominant wet scrubber technology options. The main product categories include packed bed absorbers, Venturi scrubbers, and wet electrostatic precipitators (WESPs). Each wet scrubber type serves a different purpose and is used in different circumstances. For instance, packed bed absorbers are primarily used to remove gaseous emissions like SO2, HCl, or HF. We often receive packed bed absorber inquiries for particulate removal, however, this would be a misuse of technology. Packed bed absorbers remove some particulate but they are not nearly as efficient as other options.

Figure 1: Wet scrubber technology summaryEnv wet scrubber technologies

Venturi scrubbers are used for particulate removal. Just like we sometimes receive packed bed absorber inquiries for particulate removal, we’ll occasionally get Venturi scrubber inquiries for acid gas removal. This would also be a misuse of technology. Venturi scrubbers achieve some acid gas removal, but they have poor mass transfer compared to a packed bed absorbers.  

Venturi scrubbers use mechanical forces to remove particulate. Particles are captured through a process of impaction between particles in the gas and water droplets in the Venturi throat. A high differential velocity is created between particles and droplets by accelerating the gas in the throat. A pressure drop in the throat provides energy to capture the particles. Smaller particles less than 1 micron in size avoid capture by behaving like gas molecules and finding slip streams around the water droplets. Venturi scrubber performance drops offs exponentially for submicron particulate. Overall removal efficiency may be limited for a gas stream with a high concentration of submicron particulate. Venturi scrubbers are a good choice for industrial dryers or other applications with large size particulate.

Wet electrostatic precipitator (WESP) are the third type of wet scrubber summarized in the table. Like Venturi scrubbers, they are also particulate removal devices. They differ from Venturi scrubbers in a couple of ways, 1.) electrical, not mechanical forces are used to capture particulate, and 2,) they are efficient at capturing submicron particulate. Figure 2 shows a performance comparison between a WESP and Venturi scrubber. It can be seen that performance drops off dramatically for Venturi scrubbers for particles less than 1 micron in size. WESP’s on the other hand remove particles regardless of particle size.

Figure 2: WESP, Venturi scrubber performance comparison versus particle size.

Envitech WESP Venturi Performance

The summary in Figure 1 also shows how each wet scrubber technology differs in regulatory control. A packed bed absorber is typically controlled for recirculation flow rate and liquid pH. A Venturi scrubber is controlled by recirculation rate and pressure drop. A WESP is controlled by voltage. Control limits are typically spelled out in the operating permit.

Finally, some examples of applications are given for each type of wet scrubber. It should be noted that there are many applications that have multiple types of pollutants. A hazardous waste incinerator, for instance, contains particulate, acid gases, and specific heavy metals like cadmium and lead. A fraction of particulate is submicron in size and difficult for a Venturi scrubber to remove. It is common for different types of wet scrubbers to be combined into a multi-pollutant device. Figure 3 shows a common arrangement for an incinerator scrubber. The gas is first cooled in a quencher. A packed bed absorber removes acid gases. A Venturi scrubber removes particulate and a WESP removes the submicron particulate and heavy metals.

Figure 3: Incinerator wet scrubber arrangement

Env wet scrubber arrangement

Wet scrubbers can also be combined with dry scrubbers in certain circumstances. An upstream bag-house can remove particulate followed by a packed bed absorber for acid gas removal. A cyclone can be used to knock out large particulate before using a Venturi scrubber for the remaining particulate. A cyclone helps to minimize blowdown and water consumption. In some cases, a dry filter or carbon bed absorber can be integrated downstream of a wet scrubber for mercury and/or dioxin/furan. Click here to read a blog piece about an example of a wet scrubber combined with a carbon bed.

This about covers wet scrubber basics. If you’re with an engineering company and want to discuss scheduling a lunch an learn, please give Envitech a call. You can click on the icon below for a set of Envitech brochures.

Click on the icon below to download an Envitech brochure.

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Topics: particulate control, Venturi scrubbers, Scrubbers, SO2 Scrubber, wet electrostatic precipitators, Acid Gas, Packed Bed Absorbers, Packed Bed Scrubbers, Wet Scrubbers

Horizontal Venturi Scrubber for Particulate Control

Posted by Andy Bartocci on Mon, Oct 22, 2018 @ 03:21 PM

Venturi scrubbers are mechanical impaction devices that are used to control particulate on a wide range of applications. These include medical and hazardous waste incineration, potash drying, sewage sludge incineration and processing, coal drying, mineral wool manufacturing, and copper roasting to name a few.  In one of my last blog posts I discussed a Venturi collision scrubber used to treat exhaust fumes of a Banbury mixer for rubber compounding.  The Envitech collision scrubber is used in several Goodyear Tire manufacturing facilities around the world.   


Venturi scrubber

A recent new application is a horizontal Venturi scrubber for an aggregate asphalt drum dyer.  The asphalt process is semi-stationary operating at fixed locations for several months at a time. The process is periodically broken down and moved to new locations for operation.  The horizontal arrangement makes the horizontal Venturi scrubber an ideal solution for mobile applications.  The equipment package is transportable on a single flatbed with only minor disassembly required for shipment and installation.  The equipment is mounted onto a skid with pre-assembled piping and wiring to facilitate equipment mobility. 

Particles are captured in the horizontal Venturi scrubber through a process of impaction by water droplets injected into the Venturi throat.  A fraction of particulate laden water becomes entrained in the gas which has a droplet size distribution.  The droplets are removed from the gas by a mist eliminator.   There are two pathways for particles to escape capture by the scrubber. The first is penetration.  Smaller particles lacking the mass for impaction penetrate through the scrubber.  The second is through carry over of particulate laden water droplets.  Droplet capture efficiency, or mist elimination, therefore impacts scrubber efficiency and overall plant emissions.

The horizontal Venturi scrubber uses a damper blade and actuator to maintain constant pressure drop across a wide range of gas flows.  A high efficiency chevron mist eliminator removes particulate laden droplets before the gas exits the scrubber.  A chevron mist eliminator removes greater than 99.9% of water droplets down to 27 microns with less than 0.25 inches W.C. of pressure drop.  By comparison, a cyclonic separator requires several inches W.C. of pressure drop to remove 98% of 27 microns droplets.   The advantages of a chevron mist eliminator are higher performance, larger turn down ratio, and lower pressure drop.

Envitech is currently building two new horizontal Venturi scrubbers sized for 45,000 acfm each for a peat drying operation. The compact design allows the scrubber to be easily installed inside a building. The high level of pre-assembly and lower profile reduces installation time and improves maintenance access for plant personnel.  The horizontal Venturi scrubber can be a cost effective alternative to many processes that use a typical vertical arrangement.

Click on the link below to download Venturi scrubber literature.

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Topics: particulate control, Venturi scrubbers, Scrubbers

Venturi Fume Scrubber for Tire Manufacturing Banbury Mixers

Posted by Andy Bartocci on Wed, Jun 15, 2016 @ 01:53 PM

Venturi Scrubbers are used to control particulate on a wide range of applications including medical and hazardous waste incineration, pot ash mining, sewage sludge processing and incineration, coal drying, textile and mineral wool insulation manufacturing and copper roasting. A previous blog post in April discusses the mechanisms for particulate removal by a Venturi scrubber. One application for Venturi scrubbers is removal of fumes generated by a Banbury mixer. A Banbury mixer is an industrial mixer used in a wide range of applications including food, chemical, pharmaceutical, plastic, mineral, and rubber processing. Venturi fume scrubberBanbury mixers are used, for instance, to compound rubber material for manufacturing automobile tires. Uncontrolled fumes from the mixers can create a nuisance by settling around the facility. Envitech’s Venturi collision scrubber has been used to control these fumes. The figure on the right shows a typical Venturi collision scrubber for a 25,000 cfm mixer exhaust. The scrubber separates the exhaust into two streams internal to the scrubber. The streams are then directed to two opposing Venturi throats. Recirculated water injected into each throat is atomized into fine droplets as the gas is accelerated. Fume particles and droplets collide and are captured by the atomized water as the steams are recombined into a third Venturi throat. A diffusion section redistributes the gas to a horizontal chevron style mist eliminator to remove entrained water droplets. Water is collected and drained into a common sump and recirculated back to the Venturi throats. A blowdown stream purges the collected material.

The scrubber is designed for 24/7, semi-automatic operation and is skid mounted with redundant pumps, one operating and one spare. Instruments are pre-mounted into the piping assembly and pre-wired to a junction box. The systems are often provided with an ID fan which can be mounted on the roof of the building. Typical design conditions and performance are indicated in the table below.

DESIGN VALUE
Flow Rate, acfm Up to 25,000 cfm
Temp, oF 90
Particulate, gr/dscf 0.015
Particle Removal > 99.5%*

*particles > 2.5 microns

Envitech Venturi collision scrubbers have been in operation at several tire manufacturing facilities since the early 80’s. Over 17 systems have been installed including several in recent years.

Click on the icon below to download a case study for Envitech Venturi Collision scrubbers learn how the scrubber solved the emission problems for Goodyear Tire & Rubber Company.

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Topics: particulate control, Venturi scrubbers, Scrubbers

Venturi Scrubber for Glass Furnace

Posted by Andy Bartocci on Tue, Jun 14, 2016 @ 05:14 PM

Venturi Scrubbers are used to control particulate on a wide range of applications including medical and hazardous waste incineration, pot ash mining, sewage sludge processing and incineration, coal drying, tire manufacturing, and copper roasting. One particular application is glass fiber manufacturing which can include both textile fiber and wool fiber insulation. Both types of fibers are manufactured by similar processes which use high-temperature to convert raw materials (predominantly borosilicates) into glass fibers. Emissions control is needed for both glass melting and fiber forming and finishing processes. A survey of stack test data from 10 manufacturing lines at different glass furnace operations demonstrate typical particulate emissions in the range of 0.0035 gr/dscf to 0.015 gr/dscf for volumetric gas flow rates ranging from 20,000 dscfm to 50,000 dscm. Most of these lines use a 10 in. W.C. pressure drop Venturi scrubbers. A few use wet electrostatic precipitators (WESP’s). Stack test data and particle size distribution (PSD) data indicate there can be significant differences in particle size distribution between different glass furnace manufacturing lines which account for the range in outlet concentrations. The figure on the right shows removal efficiency by particle size for a 10” pressure dropEnvitech_10_in_Venturi_curve.jpg Venturi. It indicates that nearly all particles > 2 micron in size are removed by the Venturi. Performance drops off dramatically, however, for smaller particles. Mechanisms for particulate removal by a Venturi scrubber are discussed in more detail in an earlier blog post, dated April 14, 2016.

The image below shows a typical Venturi scrubber used for glass fiber manufacturing facility. The process exhaust gas passes through the Venturi scrubber throat for particulate removal. The Venturi has a variable throat damper that is pneumatically actuated for maintaining the Venturi scrubber Venturi_Scrubber_Flat.jpgpressure drop over a minimum and maximum gas flow rate.  The damper position is governed by proportional-integral-derivative control based on the differential pressure across the throat. 

After the Venturi scrubber throat the gas passes through a flooded elbow and enters a vertical entrainment separator through a tangential inlet. Large water droplets are removed by centrifugal forces by the spin induced by the tangential entry. After passing through internals to smooth the gas flow distribution, the gas passes through a vertical chevron style mist eliminator to remove remaining water droplets from the gas. A spray header provides a periodic wash to keep the chevrons clean from particulate and debris.   Liquid from the Venturi is collected in the entrainment separator sump and re-circulated to the Venturi throat. A blowdown stream is taken from the recirculation line to purge the collected particulate.

Venturi scrubbers have proven to be highly reliable on a wide range of applications, including several collecting fibrous material. Several considerations should be taken into account to design reliability into the system.  A well designed Venturi scrubber can operate continuously with just one or two shifts of maintenance per year. Although Venturi scrubbers are quite common on glass fiber manufacturing lines some sites have relied on wet electrostatic precipitators (WESP) to meet emission limits. This may be driven by a combination of the particle size distribution (PSD) of the process and site specific permit limits. In general, a WESP is used when there is a large fraction of submicron particulate that exceeds the capability of the Venturi scrubber to meet the permit limit. A WESP has higher capital cost, but will have lower operating cost from lower energy consumption.

 

Click on the icon below to view a video of a variable throat Venturi scrubber damper blade.

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Venturi scrubber

 

Topics: particulate control, Venturi scrubbers, Scrubbers

Carbon Bed Adsorber and Filter Used to Remove Lead (Pb), Dioxin, Furans, and Mercury (Hg) to Meet New Medical Waste Incinerator Emission Limits

Posted by Andy Bartocci on Thu, Apr 14, 2016 @ 08:30 PM

WMC.jpgIn 2009, the US EPA revised the emission limits for the Hospital, Medical, and Infectious Waste Incinerator (HMIWI) MACT standard. You can follow the link to the blog piece published in May 2013 on the new standard. It dramatically reduced the emission limits for several pollutants including particulate (PM), lead (Pb), and dioxins and furans (D/F). Several existing medical waste incinerators in operation at the time were not capable of meeting the new limits, especially for lead (Pb) and/or dioxin and furans (D/F). Cost effective add-on controls were needed to bring existing system into compliance with the new rules and to allow them to continue to operate.

 

To meet this new challenge, Envitech designed a carbon bed adsorber and filter package to be installed downstream of existing wet scrubbers. The package is comprised of a new fan to overcome additional system pressure drop. Heat of compression from the fan and a re-heater duct heats the wet gas above the dew point to prevent condensation fouling in downstream filter and/or carbon bed adsorber. The system is delivered pre-assembled on a skid to reduce installation time and cost. A cartridge filter removes low concentrations of condensed Pb particulate. The carbon bed adsorber removes dioxins, furans and mercury (Hg). Envitech has upgraded four medical waste incinerators to meet the new MACT standards. All four are operational and compliant with the new standards.

In one case for Wyoming Medical Center (WMC), space was limited for add-on controls. The system had to be installed outdoors and capable of withstanding below freezing temperatures. The existing system did not meet the new limits for lead (Pb) and dioxins/furnace (D/F).The add-on controls included a cartridge filter and a carbon bed adsorber. The equipment was insulated and heat traced to maintain temperature above the dew point after re-heat. System features include:

  •  Shop and skid mounted assembly for ease of installation.
  • Insulation and heat tracing for outdoor operation in a cold climate.
  • Silicon controlled rectifier (SCR) controller to control the heater duct.
  • Compressed air pulse cleaning for automatic particulate removal from the cartridge filters.
  • Pre-wired instrumentation to a control box located on the skid.
  • Manways to facilitate maintenance access.

The system has been operational since 2014 and has been used on a routine basis during cold winter months.   The system comfortably passed a stack test in 2015. Compliance for lead (Pd) is 20 times below the limit and Dioxins/Furans (D/F) is 5 times below the limit. The re-heat and filter package has been used on several other medical waste incinerators and provide a cost effective solution for meeting stringent emission limits. 

Download a free case study to find out how Wymoming Medical Center met the new EPA HMIWI emission limits for their existing medical waste incinerator.

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Download a free white paper from the 2010 Internationa Conference on Thermal Treatment Technologies and Hazardous Waste Combustors (IT3/HWC) on the 2009 HMIWI MACT standard for medicl waste incinerators.

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Topics: particulate control, Venturi scrubbers, MACT Standards, Medical Waste Incinerator Scrubber, Incinerator Scrubber, HMIWI Scrubber

Particulate Removal Using a Venturi Scrubber

Posted by Andy Bartocci on Mon, Apr 11, 2016 @ 02:52 PM

Venturi_Westlake.jpgA Venturi scrubber is a common air pollution control device that is used to remove particulate. Because it is a wet scrubber, collected particulate is purged in a liquid discharge stream called the blowdown.

Venturi scrubbers are commonly used for industrial dryer applications (see photo). They have a relatively low inlet temperature or might have sticky particulate which prevent the use of a bag-house. Typical dryer applications include coal dryers, pot ash mining, CPVC plastics manufacturing, bio-solids sludge drying, or salt production. Venturi scrubbers are also used in insulation or glass manufacturing, magnesium mining, and hazardous and medical waste incineration.

It is important to saturate or pre-cool the gas before entering the Venturi throat to minimize evaporation. That is because during evaporation, water molecules leave the water droplet surfaces which push particles away from the droplets and reduce collection efficiency. It is also important to keep the inlet walls of the Venturi wetted to avoid fouling from wet-dry line interface.

Venturi_Mechanisms.jpg

In accordance with Bernoulli's equation, inlet gas accelerates at the converging section of the Venturi throat, increasing gas-liquid contact. As water is injected perpendicular to the gas flow in the throat, the accelerated gas particles are captured by water droplets upon collision. Three mechanisms account for collection in a Venturi which is summarized below. The adjacent graphic scrubber illustrates the three mechanisms.

 

  • Diffusion – Particle is so small its path is erratic due to Brownian motion.
  • Interception – Particle follows streamline around droplet, makes contact if within a particle radius.
  • Impaction – Particle’s inertia cause it to leave stream line and impact the droplet.

Impaction is the dominant collection mechanism for large particles, greater than 15 microns. They can be collected with efficiency greater than 99%. Diffusion and interception are more prevalent for smaller particles. Collection efficiency is lower for these particles because their small size increases the probability they will flow around the water droplets and avoid collection.

The graph below illustrates the impact of particle size on collection efficiency. The vertical axis is collection efficiency and the horizontal axis is pressure drop. The curves represent different particle sizes ranging from 0.2 to 5 microns. It can be seen that collection efficiency increases for larger particles and higher pressure drops. The net result is overall collection efficiency is dependent on the aerodynamic particle size distribution (PSD).

Venturi_Collection_efficiency.jpg

 

 

 

 

 

 

 

 

 

 

 

After particle collection in the Venturi throat, the resulting droplets aggregate through the diverging section and are separated from the process gas by the mist eliminator (ME) in the entrainment separator (ES). The ability of the mist eliminator to remove water droplets from the gas stream can have a significant impact on the scrubber performance. Any water droplets that "escape" the ME will carry entrained particulate and increase the measured outlet emissions. A more detailed discussion on mist elimination can be found in the previous blog post on “Improving Entrainment Separator Design”.

To download a free case study on a Venturi scrubber used to remove particulate from a CPVC dryer.

Download Case Study 

 

Topics: particulate control, Venturi scrubbers, Scrubbers

IT3/HWC 2015 Conference October 20-22, 2015 – Wet Electrostatic Precipitator for Medical Waste Incinerators

Posted by Andy Bartocci on Tue, Sep 22, 2015 @ 01:47 PM

Envitech will attend the International Conference on Thermal Treatment Technologies (IT3/HWC), October 20-22, 2015 at the Crowne Plaza Hotel in downtown, Houston, Texas.  The preliminary technical program can be downloaded from the conference website.   The conference features key note speakers from Veolia, Clean Harbors, Essroc, TCEQ, and B3 Systems.

Envitech will have an exhibit booth and present a paper, “Meeting the New Hospital, Medical, and Infectious Waste Incinerator (HMIWI) MACT with a Wet Electrostatic Precipitator (WESP)”.  The paper will provide an overview of a new medical waste incinerator scrubber system with a wet electrostatic precipitator to treat the off gas from two existing medical waste incinerators. The new system was required to achieve a 20% reduction in particulate (PM) emissions, and a 93% reduction in lead (Pb) emissions from the previous gas cleaning system.  The new system has been operational since October 2014.  The table below compares the performance of the emission limits to the new compliance standards. The results demonstrate the system comfortably meets the new EPA MACT standards.

 

Pollutant

 

Units

Compliance

Limit

Test Result

% of limit

Particulates, EPA Method 5 gr/dscf 0.020 15%
Pb EPA Method 29 mg/dscm 0.018 6%
Cd, EPA Method 29 mg/dscm 0.013 10%
Hg mg/dscm 0.025 1.0%
Dioxins/furans, EPA Method 23 Total (ng/dscm) 0.85 5%
  TEQ (ng/dscm) 0.020 15%
HCl, EPA Method 26 ppmv 7.7 1.6%
SO2 ppmv 4.2 35%

Click on the icon below to download a copy of the paper.

Free_Paper

Topics: particulate control, Venturi scrubbers, wet electrostatic precipitators, MACT Standards, Medical Waste Incinerator Scrubber, Incinerator Scrubber, HMIWI Scrubber

Medical Waste Incinerator Scrubber Used to Process Ebola Waste

Posted by Andy Bartocci on Wed, Nov 05, 2014 @ 08:43 PM

Envitech recently got noticed in a local news story by Michael Chen of Channel 10 News, “Local Company Helps Dispose of Ebola-tainted Waste”.  The story talks about the challenges of processing Ebola waste and how Envitech’s Medical Waste Incinerator Scrubber at the University of Texas Medical Branch (UTMB) was used to dispose of waste generated by an Ebola patient in Texas.

UTMB operates the only permitted medical waste incinerator in the state of Texas.  Since 1991 the facility has operated an incinerator which uses an Envitech wet scrubber system to clean the exhaust gases of harmful pollutants.  A new incinerator system was recently installed to meet the new EPA rules promulgated for the hospital, medical, and infectious waste incinerator (HMIWI) maximum achievable control technology (MACT) standard.  The impact of these rules is discussed in a previous blog post.

The outlet emission requirements of the new standards are a significant reduction from the previous 1997 standards.  The allowable outlet emissions for many of the metals, i.e. lead (Pd), Cadmium (Cd) are less than 1% of the previous emission limits. For example, the allowable concentrations for Pb,and Cd are measured in 10-7 and 10-8 gr/dscf, respectively.  These are some of the lowest HAPs emission limits for industrial sources in the United States. Medical Waste Scrubber Below is a summary performance guarantee for the new scrubber system based on the new HMIWI standard:

  • PM < 18.3 mg/dscm (0.008 gr/dscf)
  • Lead < 0.00069 mg/dscm (3.0 x 10-7 gr/dscf)
  • Cd < 0.00013 mg/dscm (5.7 x 10-8 gr/dscf)
  • HCl < 5.1 ppmv dry
  • SO2 < 8.1 ppmv dry
  • Dioxins/Furans < 0.035 ng/dscm on TEQ basis

Recent episodes of processing highly infectious waste from Ebola patients may re-ignite a policy debate on medical waste disposal. In the early 1990, many hospitals were going to a model of owning and operating a relatively small medical waste incinerator to process and destroy medical waste generated in-house. These systems typically have a capacity of 500 to 1,500 lb/hr. As air emission standards became stricter, many hospitals decided to shut down their incinerators and ship their waste to larger, centralized medical waste incinerators. These systems are much larger in capacity. For example, the largest medical waste incinerator facility is in Baltimore, MD with a permitted capacity of 150 ton/hr. The trade-off of a centralized waste incinerator is the risk and liability of transporting the waste on public roads and highways. The recent Ebola outbreaks bring to light that some of this waste can be highly infectious and pose a significantly greater risk to public health. It also came to light that a single Ebola patient generates a substantial amount of infectious waste. In this scenario, it may make more sense for facilities to have the capacity to destroy their own waste and avoid the risk of transporting it over great distances on public roads.

The advancement of scrubber technology and compliance with the new, more stringent EPA MACT standards, confirm the ability to operate medical waste incinerators with virtually no harmful emissions into the air.  In addition to the UTMB medical waste scrubber system, Envitech has upgraded several other medical waste incinerators for meeting the new standards.  Based on the extreme low emission limits, the results are truly groundbreaking and may encourage states and facilities to permit new systems.

For more information on HMIWI regulations, please read our white paper.

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Topics: Venturi scrubbers, MACT Standards, Ebola Waste, Medical Waste Incinerator Scrubber, Incinerator Scrubber, HMIWI Scrubber

Arsenic Scrubber for Copper Mine Roaster

Posted by Andy Bartocci on Thu, Jan 09, 2014 @ 04:00 PM

With an expanding global population, demand for minerals continues to grow.   Development of non-traditional resources is expected to increase to meet this growing demand. This includesCopper Mine copper resources challenged by high levels of arsenic.  Mining operations may incur penalties for arsenic in concentrates that exceed a certain amount.  As ore with low levels of arsenic is depleted, these penalties will continue to rise.

One facility seeking to reduce the impact of penalties is the Aranzazu project in Zacatecas Mexico by Aura Minerals.  The facility will use a partial roasting technology by Technip to achieve arsenic reduction in the concentrate.  After treatment, the concentrate is expected to contain less than 0.3% arsenic.  This will decrease expected arsenic related penalties by up to $1.00 per payable pound of copper produced.

wet electrostatic precipitator

 

The roaster off-gas will be treated by an Envitech wet scrubber system to remove arsenic with a 99.9% performance guarantee. The inlet gas to the scrubber will be at an elevated temperature well above 1,000oF and will have a high concentration of particulate, sulfur, and arsenic. The scrubber system combines Envitech’s wet scrubber technology which has been used to remove hazardous air pollutants from medical and hazardous waste incinerators with Envitech’s wet electrostatic precipitator technology (WESP) for final collection and removal of arsenic.  Envitech’s WESP technology has demonstrated high performance for arsenic removal on other furnace applications at secondary lead smelting facilities.

 For more information on the removal of heavy metals using wet electrostatic precipatators, please download our white paper on the capture of emissions from a smelter.

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Topics: Venturi scrubbers, wet electrostatic precipitators

Wet Scrubber Technology for Reducing China’s Air Pollution

Posted by Andy Bartocci on Wed, Jun 26, 2013 @ 03:01 PM

Envitech recently got noticed in a local news story by Michael Chen of KGTV Channel 10 News, “San Diego Companies Could Help Clean China’s Air”.  The story is about how California’s Governor Jerry Brown’s diplomatic trip to China could lead to opportunities for local San Diego companies like Envitech.  During his visit, Gov. Brown signed a pact that will pave the way for California companies to help China measure and improve its air quality.   As a leader in industrial air pollution control equipment, Envitech has process technology that can be used in China for reducing hazardous air pollutants (HAPs) and pollutants that contribute to regional haze like sulfur dioxide (SO2). These technologies have been applied to many processes in North America including a coal gasification plant, hazardous waste incinerators, lead smelters, sulfite pulping mills, waste oil re-refiners, geothermal plants, and mining and mineral processing to name a few.  Envitech has pursued several opportunities in China through 3rd party customers and will have one installation starting up later this year.

For more information on Envitech's capabilities, please download our product brochure.

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Topics: particulate control, Venturi scrubbers, gasification, Scrubbers, SO2 Scrubber, wet electrostatic precipitators, cleaning systems