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RHZ News

Do You Have an Obsolete PLC System?

Are you looking for the most cost effective and efficient way to upgrade?

Allen Bradley PLC2

Upgrading your Programmable Logic Controllers (PLCs) to a modern system can be overwhelming and expensive.  There are so many steps to take into account, and no transition is without its unforseen complications.  Whom do you trust to give you reliable informatio and ensure you have the least amount of down-time possible?  What system is right for you?  Are there options that would improve production and prove cost-effective in the long term, or are these bells and whistles just icing that would be wasted expenses in the long run?

Are you up to date on what systems are being discontinued by automation manufacturers?  Allen Bradley routinely posts life-cycle updates for their products, but finding out which one you have and what it's life-cycle status is can be confusing and difficult unless you know exactly what you are looking for.

We at RHZ have the experience you need  - commissioning new systems, upgrading existing PLCs for added sources or changed production practices; maintenance and custom programming to improve performance; optimization of existing programs to simplify operation or address known bugs; upgrades of complete PLC systems to modern hardware including turn-key programming solutions for your whole system, custom built for your needs.

Programming Update: Custom PLC-Based Notification Software

RHZ Environmental can now write custom software that send  out emails and text message the moment a problem occurs. Many RHZ employees receive immediate notifications if a piece of equipment we service has a problem, and daily status notifications of equipment we service on a regular basis. This gives RHZ the ability respond to issue with lightning fast speed.

Trio of Good News: Two Engineering Tests and a rebuild

This chamber was rebuilt and relinedTwo successful Engineering Tests and a Beautiful Relining: The first site had failed its previous EPA test, with an outlet concentration exceeding 6,000PPM. RHZ helped with engineering and controls modifications. The subsequent test found the average outlet VOC concentration dropped from over 6,000PPM to just over 1PPM. We also lowered the combustion chamber temperature by over 50F, which will save them over $7,000/year.  

RHZ also wrote a specialized routine which averaged the chamber temperature for each test.  Due to RHZ's skill at PID tuning, the average chamber temperature was within 0.3F of the PID's set point temperature.  The 2nd site had its engineering test yesterday. We prepped this 20 year old unit for the test a few weeks ago. It achieved a 99.97% destruction rate efficiency. This confirms RHZ's ability to achieve exceptional test results from equipment that has been in the field for decades.  The third site had falling insulation. The walls of the combustion chamber had been ravaged by years of neglect, and an entire section had to be rebuilt. This delayed our total scope of work by only Two Days.

Flash Off Managed During RTO Bake Out

A flash off is the most dangerous part of a bake out. Temperatures skyrocket, and if not understood and actively managed, can result in catastrophic structural damage.

This is a short video showing one of the chambers in a three-tower Durr RTO being baked out. This was the initial flash point for one of the towers. The cold face temperature rapidly increased by over 200°F within a few seconds. It is being controlled by a program written by RHZ Environmental. The program automatically terminated the runaway flash in its tracks. This protected the structural integrity of the chamber, meaning the million dollars worth of media, while thoroughly removing a ton of organic deposits that had plugged the media, increasing the pressure drop and gas consumption while lowering the thermal efficiency and residence time.

Enhanced Test Equipment Suite

In the past few months, RHZ has enhanced its suite of equipment aimed at analyzing and inspecting our customers' pollution abatement and other industrial processing equipment. With these enhanced capabilities, our field technicians have provided very valuable insights on the operation of a variety of critical equipment to our customers.

Thermal imaging camera

The addition of a Fluke TI400 industrial thermal inspection camera has been invaluable in finding hot spots before they become visible, and before they cause problems. It's ideal for checking electrical panels and oxidizers for hot spots, and for checking heat exchanger integrity. The Fluke uses laser-guided pinpoint focus, which is crucial for obtaining accurate temperature readings, and particularly for pinpointing problem sites.

Recent Custom Automation Programming

PLC automationRecently, RHZ was tasked with an interesting custom-programming job. The customer asked us to set up some automated routing programming for 24 silos that were filled with product from another machine, and then emptied as product was routed further in production. Traditionally, these silos would be automated sequentially, meaning that first one silo’s program would be executed, and once completed, material would then be routed to the next silo. However, the customer wasn’t operating in high production mode, so they were not presently generating a lot of product. Because of this, they asked if the automation program could be configured to pull the oldest product in any silo first, no matter in which silo that product happened to reside.

Russ wrote an algorithm that calculated which silo contained the oldest product and instructed the system to use that product first. An additional requirement that we were asked to consider was the fact that the product in each silo had an expiration time - after so many hours the product would become unusable. This was incorporated into the program so that the oldest product would be used first, as long as it hadn't expired. If the contents of a silo had expired, that silo would be removed from the usable queue and the operator was given the ability to enable a flush routine to dispose of the expired product from just that one silo. And as a maintenance mode contingency, operators were also given the ability to choose which silo to fill, so that damaged silos could be removed from the queue until repairs could be made.

We quickly completed the programming and are now monitoring the system to verify that it continues to meet all of the customer's operating requirements.

Ground Conduit in Freezing Conditions

Two months of temperature variations in Alliance, OHDuring the last several years, we've had a historically cold and changeable weather environment during North American winters. We at RHZ have started to see some equipment issues caused as a result. If you are encountering intermittent electrical problems with any of your exterior equipment, keep in mind that underground conduit may be compromised by a changing frost line. It has been helpful for us and our customers to consider this when troubleshooting these types of issues. Since we have previously had several years of fairly benign winters, it sometimes doesn't occur to our customers that the depth of the frost line can be impacted when the weather is as dynamic and extreme as we've seen in recent months. Not considering these buried conduits has the potential for a lot of time and money to be wasted in chasing red herrings, such as suspecting expensive equipment to be faulty when in actuality the wiring could be the cause. 

Tuning Gas Flow

LEL LevelsIn the past couple of weeks, we've made a few minor programming modifications and helped stabilize some systems that were giving their owners quite a lot of grief. The key to this was understanding the relationship between LEL (Lower Explosive Limit) concentrations and face velocities in their particular equipment configurations.