We at Cycle-Therm, Inc. USA take strong exception to that perception

Oct. 10, 2014 - PRLog -- Cycle-Therm are constantly reinventing themselves when it comes to RTO design, making their equipment simpler and more flexible in design, more robust in construction, more reliable in operation, simpler to maintain, more economical to operate and most of all, less expensive to purchase and install.

We have been building RTO’s since 1978.  In fact, every vertical flow RTO built worldwide is based on our Principal’s 1984 patent.  We are no strangers to innovation.

Cycle-Therm is constantly pushing the thermal efficiency and power usage envelope by developing and using Heat Recovery Media (HRM) designed specifically for RTO systems that tolerate thermal abuse while offering the lowest pressure drop and highest thermal efficiency on the market today.  In fact, using our ULTRA low-pressure drop random packed media as a replacement to 1” saddles will cut HP by 1/3^rd, without thermal efficiency loss experienced by other low pressure medias.

All of our 2 chamber designs come equipped with a “built in” chamber transfer system that switches chambers in lightning fast ½ second execution.  It does this without the use of pneumatic or hydraulic valve operators.  The transfer system is patented and has totally eliminated the destructive problem of the valve seat crashing into the valve seats.  This, in itself, is remarkable when you consider that you are moving a 200 lb disk and shaft 18” in ½ second.  The design consistently stops the valve motion gently when it contacts the valve seat thereby eliminating the self-destructive problem normally encountered by “crashing” into the valve seat.  We have been installing this system since 1998 and have never had to replace a valve disk.  Since all valve disks are connected to a common drive shaft in a balanced counterweighted arrangement, they move in unison without the chance of one disk moving out of sync from the other.

All of our two-chamber RTOs sized from 2,500 to 25,000 SCFM are shipped in two sections (one combustion chamber section and one recovery chamber section).  All on-unit instrumentation, including the burner pipe train, is pre-wired to an on-unit NEMA 4 junction box.  Operating controls can either be mounted on the unit, inside the confines of the facility, or a variation of both.  Units to 55,000 SCFM are shipped in five sections (two recovery chambers with integral valve transfer system, two combustion chamber sections and one burner section).  In any case, whether it is a 25,000 SCFM or a 50,000 SCFM unit, both systems sit flat on the ground, not elevated 10 feet on columns.

In our twenty years of experience, Cycle-Therm has not encountered any driving reason to normally supply a push fan RTO system for forced draft operation.  The main reason other manufacturers offer push systems is because they typically require lower fan horsepower.  Pushing the process air through the system requires lower fan horsepower since the incoming process air is at a lower temperature and higher density than the higher temperature, lower density air on the outlet of the RTO.  This is coupled with the fact that in larger systems the cost advantage in purchasing a smaller fan keeps the supplier competitive by quoting a piece of equipment with a lower capital cost.  Capital budgetary considerations always outweigh the down side of using a push system on the surface, but there is more to be considered.

Because of Cycle-Therm’s propriety Cell-Stone®ULTRA low pressure drop HRM, our systems require, at a minimum, 1/3 less HP than our competitors’ push system while using a pull configuration.

While we prefer to build negative pressure systems because of safety, fan cleanliness, fan balance, fan maintenance, fan life enhanced by the fact that we can attain a higher destruction efficiency using an induced draft system, we have no issues in supplying a reliable push system if the customer so desires; however, we feel that we can competitively meet any constraint put forth in support of a push system…it’s all a matter of system and fan design.

We can design systems that have round/oblong chambers or a system with square/rectangular chambers.  We commonly opt for the round/oblong design because of the natural hoop strength created in the recovery and combustion generated by this design.  The round/oblong configuration adds to fabrication efficiency by fabricating the recovery chambers by rolling 2 sections and welding them together instead of welding 4 sides and then welding on channel deflection stiffeners in the square/rectangular design required to increase load deflection strength.  We believe that in a 2-chamber RTO, especially because of the chamber transfer pressure pulse generic to all 2-chamber RTO designs, the hoop strength generated by the round surfaces is especially important as it supplies the shell rigidity needed to slow metal and weld fatigue.  Simply stated, our design increases strength by minimizing flat surfaces.  The oblong RTO in the larger flows also generates an economical and efficient chamber transfer flow path that allows us to build the unit without the typical external valve manifolds.

There are segments of the marketplace that are convinced that structured or extruded monolith is the only heat recovery media to use when designing a RTO system.  It is our experience that different applications have different requirements.  There is no rational requirement to change to a rectangular RTO configuration as structured or extruded packing can easily be substituted by random packed saddles in our oblong RTOs.

For customers that have a requirement for, or favor the reliability and ultra-high destruction efficiency generated by the 3+ chamber RTOs with a purge cycle, we design a continuously rotating valve drive system that opens and closes in unison with virtually 100% leak free poppets.

Poppets are used instead of the traditional butterfly valve design since poppet closure disks move latterly against a seat generating uniformly tight compression, unlike the butterfly valve that rotates around a pivot shaft.  Butterfly valves generate proportionally increased leakage the further the distance from the pivot point.  This becomes a very pronounced problem over time and requires constant cleaning to maintain destruction efficiencies.  This is particularly inherent when there is tacky particulate in the process air stream that adheres to the flat butterfly pivot disk and flat contact seat.  The greater the amount of valve leakage, the greater the amount VOC’s there are bypassing the RTO and being emitted into the environment.  Beyond one-quarter of one percent leakage per valve in a 3-chamber RTO, where 3 valves are always closed, is not acceptable when a system is required to meet 99%+ destruction efficiency.