Dry Flocculant Mixing and Feeding Design Considerations
This is a guest post by Bill Hancock, President of Zeroday Enterprises
Dry Flocculant Mixing and Feeding Design Considerations
Dry flocculant wetting, dissolving, mixing and solution feeding must be done under very specific controlled conditions that account for the flocculant’s unique physical and chemical characteristics. Failure to ensure proper polymer solution preparation and feeding can result in mix-feed system plugging and erratic operation, process control issues and wasted polymer.
Key flocculant characteristics that must be considered for proper flocculant mixing and use are summarized below:
1) Flocculant powders are hydroscopic. Storage and dry polymer feeding systems must ensure minimum air contact as the particles will adsorb moisture which initiates flocculant dissolution. Dissolving particles are very sticky and consequently will aggregate into larger pieces and chunks. These larger pieces and chunks dissolve slower and often can plug equipment causing mix system and even process operational disruptions.
2) Water wetted flocculant particles can aggregate into masses. Since flocculant particles dissolve proportionately to exposed surface area, particle aggregates that have stuck together result in significantly reduced dissolution rate during mixing. If the flocculant aggregates do not fully dissolve within the set system residence time, these partially flocculant masses will pass through the mix system and process unused. And possibly plug equipment. Note: flocculant particles/aggregates will hydrolyze throughout into a clear gel which refract light differently than water, these masses are called ‘fish eyes’ because can predominantly see the light refraction, not the mass itself.
3) It is very important to initially wet each flocculant particle. The mixing system must be designed in the first step of the mixing process to wet each particle individually and immediately, and subsequently ensure these wetted particles do not aggregate or agglomerate. There are two main mix system flocculant particle wetting categories.
- Augering flocculant particles into a funnel with plenty of water flowing in the funnel followed by some motive dispersive force to ensure any particles that might stick together will be pulled apart.
- The flocculant particles are air blown from an auger into a large diameter hose to the top of the mix tank where cascading water inside a tube wets the particles which enters the mix tank and impeller.
4) Flocculant dissolution time variable. Flocculants dissolve at different rates, primarily dependent on the following factors.
- Type of polymer charge
- Flocculant charge level
- Water temperature and chemistry
Required mix times can range from 30-90 minutes are designed into a mix system.
5) Flocculant solutions are viscous. Dissolved long chain flocculants introduce solution drag that is expressed as viscosity. The amount of viscosity is dependent on the flocculant charge, charge level, temperature, concentration and molecule chain length. More viscous solutions require more mixing power. To ensure the flocculant molecule chains are not broken, balancing the amount of power in mixing and the type of mixing are crucial for minimizing dissolved flocculant chain damage.
6) Low shear pumps must be used for flocculant solution transfer and feeding. The two more predominate low shear pump types are progressing and diaphragm. More specifically, examples of pumps that are acceptable include progressive cavity, peristaltic, gear, lobe and air operated diaphragm.
7) Flocculant solutions typically provide best performance at ≤ 0.1% concentrations. To optimize flocculant mixing system sizing, flocculant solutions are often designed to be mixed to 0.25-0.50% maximum concentration. Once dissolved, the flocculants will dilute readily with teed in water down stream of the flocculant feed pump to obtain the final target 0.1% concentration.
Flocculant mixing and feeding is not highly complex. But the unique flocculant characteristics accounted and designed into a mixing-feeding system to ensure optimum preparation and minimized consumption.
Bill Hancock is an internationally recognized expert in mineral processing technologies, technical marketing management and water treatment. Hancock founded and owns Zeroday Enterprises which supplies chemical mix-feed systems, LTM conductive slurry level monitoring probes, peristaltic hose and tube pumps, mixers and flocculant and coagulant chemicals. He also founded Argo Consulting—a technical and technical marketing consulting practice focused on providing mineral processing, water treatment and technical marketing consulting services to the mining industry.
Exciting New Partnership with Zeroday Enterprises
Announcing New Partnership with Zeroday Enterprises
Mainland Machinery Ltd and Zeroday Enterprises LLC are pleased to announce a partnership to advance Zeroday’s chemical mixing and feeding technology. As of August 9, 2016 Mainland has been named the exclusive distributor and manufacturer of Zeroday’s Z ChemGear product line of flocculant, chemical and regeant mixing and feeding systems!
Zeroday is an industry technology leader in process, water and wastewater treatment, and brings extensive chemical knowledge and experience used in designing quality, effective and robust chemical mixing-feeding systems. Mainland has over 45 years of value added manufacturing and engineering experience with involvement in diverse industries such as mining, oil & gas, municipal infrastructure, industrial agriculture and ports & terminals. The mutually supportive skills and core capabilities of each partner will enhance business competitiveness, capabilities and product line strength.
With locations in Wilsonville, Oregon and Abbotsford, B.C., we will continue to sell and support systems globally through EPCM, third party vendors and directly to customers. Canadian sourcing is expected to make the mix-feed systems much more competitive.
Zeroday’s Principal, Bill Hancock, is internationally recognized for his expertise in mineral processing technology and water treatment, and holds patents in flocculation and flotation applications. Bill will be involved in product line, sales and technical support, as well as independently promoting product line sales.
Mainland is pleased to be working alongside Zeroday Enterprises to produce innovative and cutting edge technologies! And Zeroday is excited about partnering with Mainland who will provide greater engineering and fabrication resources and expertise.
To inquire about products to meet your floc system neeeds, please contact sales@mainlandmachinery.com
To learn more about Zeroday, see their website
HELP US BREAK IN OUR NEW BRAKE PRESS – INTRODUCTORY RATES!
HELP US BREAK IN OUR NEW BRAKE PRESS – INTRODUCTORY RATES!
Mainland Machinery’s Machining Center is fully operational and capable of meeting your heavy plate forming and project needs.
Our recently opened third facility located in Aldergrove, BC features our new Accurpress Model 7 1500 16 Brake press with ETS3000 Control System.
Mainland Machinery’s state of the art Accurpress Brake Press is now available for your heavy plate forming needs. We are pleased to announce that we are currently processing orders for its use at introductory rates.
Visit our website for more information and to submit a request form
Product Capacity
- 1500 ton
- 16′ Bed with increased opening of 4″
- 575 Volt motor
- Series 7 (rocker arm style)
- Die Holders
- 12W-2H-16′
- Bends 1″ plate
Visit our website for more information and to submit a request form
When Precision Counts, Count on Laser Cutting Technology
When Precision Counts, Count on Laser Cutting Technology
Experienced metal fabricators know that when it comes to projects that require the utmost in precision cutting, there is no cutting corners by using outdated and inefficient equipment. Laser technology has provided the fabrication industry with not only the means to allow for more precise manufacturing, but also a way to make their operations more efficient and less costly.
What is Laser Cutting?
The origin of the word LASER stems from the acronym for “light amplification by stimulated emission of radiation.” Laser cutting is accomplished, true to its name, through a process that stimulates emission. Laser cutters for industrial use are able to cut through flat sheets, piping or structural metals. Cutting is made possible by the laser’s ability to burn, melt or blow away the area to be cut.
Electricity or special lamps used within a closed environment generate the power needed to charge up the material that creates the laser beam. There are three types of laser cutting available to metal fabricators, including:
- CO2 for boring, cutting and engraving
- Nd for boring that requires high-energy
- Nd-YAG for when high power is required
Both the Nd and Nd-YAG lasers are used in the welding process.
Different types of material require different types of laser beams using various methods to allow for cutting. These methods include, but are not limited to:
- Burning stabilized laser cutting
- Cold cutting
- Melt and blow
- Melt blow and burn
- Scribing
- Thermal stress cracking
- Vaporization
A typical laser cutting setup for a metal fabrication shop includes:
- A power source to produce a laser beam
- Positioning table to secure material with clamps, magnets or straps
- Laser material
- Stimulation apparatus
- Mirrors
- Lens for focusing the laser beam
Pros and Cons of Using Lasers for Cutting
Laser cutting is more precise than mechanical cutting methods because machines can be easily contaminated from the materials that are being cut with them. Additionally, their blades are subjected to continual use that can dull them and cause their cuts to be inconsistent which can often lead to wasted material.
With laser cutting, you can expect:
- Cleaner cuts without burrs that require additional processing
- Faster production time
- Less human error
- Improved accuracy resulting in waste reduction
However, using laser cutting machinery does have a few drawbacks. It requires more energy than mechanical cutting methods. Because of the heat process involved, the laser process requires a cooling source, where water is commonly used as a coolant for a heat transfer or chiller system.
Advances Continue to Make Cutting Process More Efficient and Cost-Effective
Improved technology continues to develop cutting equipment that will require less laser gas and power to operate while dramatically improving cutting speeds and accuracy. These advancements help to increase production and transform other areas of the business process for metal fabricators who are taking advantage of this technology to greatly improve their bottom line.
Sheet Metal Fabrication; Electroplating vs Painting?
Sheet Metal Fabrication; Electroplating vs Painting?
Choosing a finish is an essential step in the sheet metal fabrication process. Finishes can prolong the lifespan of metal parts, improve their cosmetic appearance and increase their suitability for their intended use. There are a number of options for finishing sheet metal parts, but two of the most common are electroplating and painting. Both of these options offer distinct advantages as well as certain drawbacks depending on the product’s purpose.
Electroplating vs Painting
Electroplating is the process of attaching a thin layer of one metal, such as chrome, iridize or zinc, to the surface of another base metal, such as aluminum. The plating is chemically bonded to the surface of the base metal through electric conduction. Electroplating should not be confused with anodizing, which involves bonding an additional layer of the same metal to the base product through the same electrochemical process.
Painting is more straightforward and most people are familiar with it. A primer is first applied to the base metal, followed by multiple layers of liquid paint and finally, a protective coating such as lacquer is added to protect the underlying paint.
Advantages and Drawbacks of Electroplating
Electroplating offers a much stronger finish than paint. Depending on the choice of metal used for electroplating, the object may have better resistance to chemical corrosion or increased physical durability. For example, zinc offers additional resistance to water damage, while chrome reduces the friction on the metal’s surface and tin can be used to join aluminum, which is commonly used in sheet metal manufacturing, to dissimilar materials. Certain finishing metals can also increase paint adhesion to metal parts as well.
Because electroplating chemically bonds the finish to the metal product itself, the coating expands and contracts at the same rate of the base metal itself, making it suitable for environments with drastic temperature fluctuations.
However, electroplating can be expensive and uneconomical, especially when parts are small. Furthermore, the advantages offered by electroplating may be excessive if the metal product is intended for a use that does not take full advantage of the benefits offered by the process.
Advantages and Drawbacks of Painting Sheet Metal
The most obvious advantage of painting is that fabricators have a much greater degree of control over how the finished product will look. Paint comes in just about any color imaginable, meaning that there are endless options for how the final product will look. Furthermore, company and product logos can also be added to the surface to further increase its cosmetic value.
Certain paints offer similar advantages to electroplating; some can increase the metal product’s resistance to chemical corrosion or physical damage, though not to the same degree as electroplating. Damage to specific areas of painted surfaces is easily repaired as paint can be applied quickly and easily to small areas of a product’s surface. Another advantage paint has over electroplating is that it can be applied to certain areas of a product’s surface if the entire product does not require finishing. Unlike electroplating, painting is not an “all or nothing” process.
Paint, however, is not as durable as electroplating. Furthermore, because paint is applied as liquid, it can take many applications to ensure a finish of even thickness and color.
Which Option is Best For You?
Electroplating and painting each offer unique advantages for finishing a sheet metal product. Ultimately, deciding on which finishing option is best for you depends on the intended use of your product. It is important that you consider all factors and the advantages and drawbacks of each before making a final decision.
Sandblasting Helps Save Time and Money
Sandblasting Helps Save Time and Money
A major challenge facing many industrial companies is how to get more use out of their storage tanks. Often companies simply purchase new tanks without trying to repair or restore their existing tanks. However, what many companies may not realize is that sandblasting provides an easy way to repair and restore their tanks to almost new condition. Sandblasting is a time and cost-effective method for maintaining and restoring existing tanks.
What is Sandblasting?
Sandblasting is the process of shooting a gritty, particle-based medium such as sand, glass beads or aluminum sulfide onto a hard surface to sand or polish it smooth. There is a variety of purposes where sandblasting can be useful. It can be used to clean pollutants or remove rust from storage tank walls or to prepare them for repainting or recoating.
Sandblasting is an extremely versatile process because of the many types of mediums that can be used. For example, a more delicate tank lining may require a gentler sandblasting medium such as walnut shells or glass beads. Tougher jobs, such as those found in oil storage tanks or where the tank surface must be stripped to bare metal may require a more abrasive medium such as silicon carbide.
Save Money By Recycling What You Already Own
Including installation, a new tank could cost more than $20,000. However, an existing tank of the same size can be sandblasted, have its leaks welded and then be repainted for under $4,000. This is less than 25 percent the cost of a new tank. You can add five to 10 years to the lifespan of tanks by choosing to have them sandblasted.
Most sandblasting mediums can be reused multiple times. Glass beads are often recycled from glass bottles and may be used for sandblasting up to 30 times. Other mediums, such as silicon carbide, may also be reused multiple times.
Some of the mediums used can be made from byproducts produced with a water jet cutting process used in some metal fabrication shops. This further reduces their cost. An added advantage with some mediums, such as walnut shells, is that they are fully biodegradable, thus saving money on their clean up and disposal costs.
Reap the Benefits of Sandblasting
It is possible to save time and potential headaches that come with buying a new tank or replacing your old one. It can take months to fabricate, transport and install a new tank. In many cases, the entire sandblasting process from site preparation to cleanup can be completed in less than a week. The most abrasive sandblasting mediums can further reduce downtime because they can achieve the same results as softer compounds but in less time.
Most sandblasting companies are full service and take care of all aspects of the process, including other repairs that may arise and site cleanup. This helps alleviate hassles you might encounter trying to coordinate a new tank install. As a result, sandblasting effectively reduces your usage downtime because your tanks are out of commission for a shorter amount of time than they would be if you chose to replace them.
With sandblasting, your old tanks can be restored to their former condition, quickly and inexpensively. This can be beneficial if your tanks are located in a visible location or an urban area where old rusty tanks might be considered eyesores.
