The Secondary Materials and Recycled Textiles Association (SMART) lauded the city of San Francisco’s effort to add used clothing to its recycling program.Add a comment
contributed by FAIRBANKS SCALES
In today’s recycling and solid waste industry, uptime is of utmost importance. Most facilities experience long lines at the scale, and so they place a premium on getting trucks in and out quickly. However, have you ever stopped to think about how much you could be losing per truck?
When businesses place scales in service, the state Weights & Measures Department certifies that it meets the necessary regulatory requirements. Unfortunately, external variables and real-world issues can knock your scale out of calibration and cost a business a lot of money.
But just how much could it cost?
A simple error of one increment (20 lbs.) can lead to $30,000 in annual product loss! This is a real example and is based on a product with a value of $.05 per pound and a duty cycle of 100 weighments per day. The following best practices can help prevent such an expensive scenario.
The simplest step you can take is to implement a calibration and inspection agreement with your service provider. Depending on the requirements and type of weighing device, inspection costs can be as low as $500 annually depending on the frequency required to assure accurate weighing and to reduce the risk of loss due to an inaccurate scale. Compared to the potential loss figures, this is a worthwhile investment.
But how often should your scale be inspected? Fairbanks Scales, a provider of industrial weighing equipment and service, recommends a minimum of two inspections per year for most scales, but the sort of heavy traffic which recycling and solid waste facilities experience can easily justify more frequent verification, inspection and service. Consult with your scale service company about a schedule that works best for your company.
Recycling and solid waste operations can generate a lot of debris. Be sure to regularly remove the build-up to avoid scale inaccuracies. A pressure sprayer is a fast and easy way to clear debris and keep the scale and foundation free of build-up. Be sure that your junction boxes, electronics and load cells are properly rated to withstand pressure washing; otherwise you may cause damage.
Inspect for anomalies. A properly operating scale is dependent on every component working together. Inspect the weighbridge for damage or signs of wear and corrosion. Examine the junction boxes inside and out. Do they show signs of damage, corrosion or moisture entry? Module connection hardware should be intact and not damaged. Check the load cells for damage, corrosion and signs of moisture entry into the enclosure and the cable entry gland. Liquid is a good conductor and can easily short your electronics if allowed to enter the sensing element area.
Some manufacturers feature quick disconnect style load cell cables. Be sure to inspect these connections frequently as they are responsible for a significant number of avoidable failures. This is also a good time to inspect the wiring for damage. Exposed conductors cause communication errors when wet and are usually the culprit of erratic performance.
Your scale’s paint system isn’t just for good looks. It’s a critical barrier against scale corrosion on your weighbridge steel. Be sure to reapply if you expect maximum life from the weighbridge steel.
Grease the load cell cups at recommended intervals. Some manufacturers incorporate zerk type fittings allowing grease application without the need to physically separate the load cell components.
Inspect concrete for signs of failure. Address these issues as soon as possible. Left unchecked, they will only get worse and will cause larger, and more costly, problems.
Your weighbridge will expand and contract slightly at different times of the year; this is natural. This thermal expansion requires attention and readjustment of your checking. The checking system on your scale keeps the weighbridge in place as it naturally rocks and moves from traffic. Too small a gap in the checking can cause binding and weighing errors. Too much gap in the checking allows excessive movement, up to and including a scale tipping. Excessive movement adds unnecessary wear to other components, so be sure the checking is properly secure.
Today’s truck scales use sophisticated electronics to communicate weighment data to the instrument. A securely grounded scale is a basic defense from lightning and power surges. Be sure that the scale is connected to the manufacturer’s specified grounding system and that there are no interruptions in this system. Transient voltage seeks the easiest path to ground. If your scale isn’t grounded through a ground rod connection, it surely is grounded through other components. Disrupting the ground connection shunts power surges to other places, like your load cells or electronics. Damaged electronics can cost thousands of dollars in repairs.
You probably don’t have the time to monitor how fast traffic enters and exits the scale. However, keep in mind that while the scale is designed to slightly move with traffic, abusive and aggressive entrance and exiting of traffic accelerates wear. Again, taxing the scale means more wear and more dollars spent in repairs.
Many scale manufacturers offer accessories to promote traffic discipline while entering and exiting your scale. Traffic signals and guide post kits at the approach and exit can manage traffic flow and truck speed very effectively for a small investment.
Install accessories where necessary Consider the accessories below, developed from real-world experience, to prevent issues with your truck scale altogether.
Riser plates – Riser plates elevate your weighbridge, reducing the risk of debris accumulation and providing clearance for cleaning and inspection.
Load cell boots – Exposed to debris, weather, moisture and even product that has migrated below the deck, your load cells operate in the worst environment possible. Load cell boots act like a protective glove and prevent debris from interfering with proper load cell operation.
Steel and EPDM rubber belting – At each end of your scale, there is a small gap between the scale and foundation. This gap is a great place for dirt, debris and product to fall under the scale and accumulate. Installing T-belting along this gap between the scale and foundation wall is a good step to preventing this accumulation.
In the end, how you implement these best practices is up to you. You can partner with a qualified service provider to manage these tasks, or you can go it alone. One thing is certain – neglecting your scale costs you profit.
Published in the April 2014 Edition of American Recycler NewsAdd a comment
Maui Mayor Alan M. Arakawa executed an agreement with the Maui Resource Recovery Facility, LLC, to finance, design, construct, own and operate a state-of-the-art resource recovery facility,Add a comment
Inventor and entrepreneur LeRoy G. Hagenbuch has granted a non-exclusive license related to a portfolio of patents directed to radio frequency identification (RFID)-based refuse container interrogation and collection.Add a comment