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Sunday 15 November 2015

High Temperature Blower II

                                                High Temp. & High Pressure Blower II


Further to the 2012 post "High Temperature Blower at Work"and 2011 post "High Pressure & High Temperature Industrial Blower"; NXT Roasters has been working on an air bearing package that will deliver the same pressure and volume but at higher temperatures.

High temperatures create a hostile environment especially to an object that must turn at high speeds.  Materials must be carefully chosen so that they will maintain their strength and hardness at the elevated temperatures.  Thermal expansion creates problems as well because not only do different materials expand at different rates but various components operate at different temperatures.  That "constant" X 10-6 per °C can really bite you.

Common bearings can handle high temperatures and high speeds but rarely can they do both in the same application.  The high speeds (above 10,000 rpm) mean that the components have to be dynamically balanced plus tight tolerances have to be maintained.

The initial goal was to place the Blower in the coffee roasters where it should easily cope with the 250°C recirculated air.  Curiosity drove the project to higher and higher temperatures.  The current temperature ceiling will remain until a stainless steel housing is fabricated.


Earlier this week a blog reader  requested information on a blower capable of moving flue gases.  Unfortunately the 800°C flue gasses are 300° higher than we have been running the Blower, that temperature is beyond the capacity of the 6061 Blower Housing.  

There are some obvious applications for the Blower but it would be interesting to find out if it is able to solve or enhance some industrial processes.  Email your suggestions and requests to main@nxtroasters.com  .  Perhaps our development plans will coincide.

In the meantime we will continue to accumulate operating hours.


Friday 27 March 2015

NXT Generation III Roaster

 
NXTRoasters Inc. is introducing its third generation advanced roasting system, which protects the purchaser’s investment, consumes the lowest possible energy, and exceed strictest air pollution standards Training time to roast is finished in days instead of months!  Its two-step roasted coffee bean cooling system provides outstanding repeatability of roast degree.

The System combines in a single unit:
  • A roasting and a heating chamber,
  • A chaff catcher,
  • Two afterburners,
  • Pneumatic conveyor to load green beans into roasting chamber, and transfer roasted beans to the packaging hopper

The NXT roaster is practically maintenance free, with threat of fire nonexistent!  Chaff from the air stream is separated prior air entering the heating chamber.  Roaster develops no tar deposits.


Specifications:

Batch capacity: 3 kg (green beans)
14.4 kg/Hr (roasted coffee beans)

Motor horsepower:
Main blower:                         2.2 kW
Pneumatic conveyor:             1.5 kW

Temperatures: Adjustable
Roasting: 235°C – 265°C

Heating:
Main heater:                           10 kW
Smoke Eater:                         1.5 kW  
Power consumption:      6.0 kW / Hr.
Including Built-in Afterburners!

Cycle Times: 8 – 12 minutes

Dimensions: 50” x 36” x 80