Why Is My Blow Detector Inconsistent?

Why Is My Blow Detector Inconsistent?

Other Blow Detectors Can’t Meet Performance Standards. The Reasons Are Clear.

There are two primary problems with ceramic crystal transducers used in blow detectors. The first is that they’re finely tuned devices (with a high Q factor) where the transmitter and receiver need to operate within in an exceptionally narrow frequency band. These devices tend to drift – and not necessarily together. Because of the narrow frequency requirement, a small amount of drift can have a dramatic impact on received energy. This causes the detector to trip on false positives – an expensive proposition for a plant.

The second problem has to do with resonant frequencies and broadband applications. A typical transducer includes a transmitter and receiver. A standard Miloptic transmitter produces a narrow band output targeted at frequencies in the 16-95khz range. The receiver – which is broadband over this range – is electronically narrow-banded later in the process. This allows the system to be tuned to a “sweet frequency” – one that is ¼ or ¾ wavelength in the material being inspected. At ¼ wavelength, or a multiple thereof, the material approaches transparency – making it much easier to penetrate. However, piezoelectric ceramic crystals do not like to be driven off their resonant frequency – and, therefore, are not effective in broadband applications.

I have encountered both of these problems based on decades of hand-on experience. In 1968, I worked with my team at Trienco – now Miloptic – to build and install the world’s first air-coupled blow detector. Initially it worked great – but when it was installed into a high-production mill, we started to see issues.

The ceramic crystal transducers in the initial design drifted – causing inaccurate positive readings. Our testing at the time showed that blow detectors with ceramic crystals will never deliver consistent results under high-production conditions. It took some time, but by mid-1973 we successfully developed our exclusive transducers without ceramic crystals. The Trienco 506 system was born.

Since then, we have successfully installed over 220 Trienco 506’s. We are extremely proud to report that many of them are still in service – after 30 years of operation. As technology improved and our engineering expertise has increased, we launched the 5600 and current 5700 product lines. The new 5700 series has been designed to integrate with Rockwell and other PLC solutions. It also provides solutions for many different panel types – in addition to flooring, gypsum, and siding. And best of all, Miloptic’s products are made in the USA.

Want to learn more about the differences between the Miloptic transducers and their ceramic counterparts used by most of our competitors? Feel free to call us at 503-213-2013 or email us at support@miloptic.com.

Looking to Upgrade a Conveyor? Ask These Questions First

Looking to Upgrade a Conveyor? Ask These Questions First

When it comes to upgrading conveyors, it’s important to move deliberately. For starters, you’ll need to assess the space, infrastructure, and equipment in place. Because a conveyor expansion or modification represents a substantial capital investment, you’ll also want to carefully analyze all available options. You need to weigh benefits against costs and assess your tolerance for risk.

At Crow, we are continuously involved in projects to help customers achieve and exceed their expansion goals. In our experience, when designing conveyor layouts, it’s important to consider the following during the conveyor design process. Going through these simple considerations can greatly reduce design mistakes and help you avoid costly operational downtime in the future.

  • Material
    What is being conveyed? What is the product size, composition, flowability? How will the material behave as it is being handled or processed? These questions help you figure out the best type of conveyor and chain to choose for the uses you have in mind.
  • Operation
    Here, we consider operational requirements around function and performance. A key metric is the amount of material you intend to convey in a specified timeframe. Knowing the demand for such material at each process or operation point will guide your decision-making from the start. Also consider hours of operation. How often do you expect the conveyor to run?
  • Environment
    Every conveyor runs in some type of environment. What is your environment like? Can it withstand the rigors of relevant environmental extremes – such as temperature, humidity, corrosion, vibration, etc.? Another important question: Are their open sources of ignition? Will the environment be flammable or explosive? Answers to these questions might lead you to consider explosion-proof motors, corrosion-resistant bearings and shafts, or other design choices.
  • Footprint of conveying system
    Your conveyor needs to fit in the space allotted. When designing new or modified conveyor equipment, particularly when some portions of the system already exist, important considerations include infeed/discharge elevations, centerlines, and the operational speeds of existing machines that work with the conveyor. Also, is anything in the way? Do you have to avoid columns, ceilings, walkways, mezzanines, material staging areas, or pedestrian or forklift traffic?
  • Maintenance
    How easy will it be to perform regular preventive maintenance? Can you quickly swap out chains, bearings, motors, belts, shafts, sprockets, etc.? These are important design considerations with an obvious goal – to maximize maintenance efficiency and minimize the potential for costly downtime that comes with machine failure.
  • Conveyor components
    Is your conveyor designed with components that are easily sourced? Can they handle the environment? Are they available from local distributors? Are they cost effective? The last thing you want is for operations to come to halt for want of an essential part that’s difficult to find.
  • Safety
    Does your conveyor design follow applicable OSHA requirements and local laws? Does it have proper guarding at pinch points or known hazardous areas? If pinch points/hazards cannot be guarded, could you fence off the conveyor or system to restrict access and potential accidents?
  • History
    Be sure to listen to the experts. They’ll provide insight into what has and hasn’t worked in the past. When replacing existing equipment, the importance of functionality, reliability, and service history should not be overlooked. At the same time, your own history is critical. If conveyor reliability or functionality has been an issue for you in the past, understanding these issues can lead to suitable design changes and countermeasures. The result is more satisfactory results for your material flow goals.

Trust in Crow

By considering the questions discussed here – and by remaining in constant communication with the customer – Crow has helped many customers achieve their conveyor design goals. We provide full design or on-call engineering for small and fast-track projects that need to be handled quickly with a minimum of expense. We manage the initial design and can also support the project throughout construction.

If you have conveyor modification, upgrades, and expansion plans, be sure to tap the kind of expertise that can help you avoid mistakes, minimize costs, and ensure success. Give Crow a ring at (503) 213-2013. We’d be happy to talk. 

 

 

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