“We Bring Engineering to Life” 2015 Agent Training Grant Ellington Nov. 18, 2015

Topics Energy cost update Automatic ventilation controls Heat recovery system evaluation Modular tray steaming system Farm Safety information

Source: U.S. Energy Information Administration (LP Gas – Wholesale/Resale; N.G. – Commercial) LP Gas and Natural Gas Price Outlook $18 / $1.30/gal $9.40 / $0.75/therm $11 / $0.80/gal $8.10 / $0.65/therm

Natural Gas ($/therm) LP Gas ($/gal) No. 2 Fuel Oil ($/gal) Wood Chips ($/ton) Fuel Cost Comparison * Heating System Efficiencies are assumed equal 2014

Automatic Ventilation Control – Improving Curing Management and Energy Efficiency Most automatic systems measure relative humidity directly, but display dry-bulb and wet-bulb temperature.

2014 County Agent Survey Data (85,000 acres reported)

Real-time Continuous Monitoring of the Curing Environment Significant time management tool for growers Web-based access to monitoring system Audible alarm conditions to help minimize leaf damage during equipment failures or power loss Data logging capabilities Suretrol or Cureco, Marco Mfg., Enercorp (Flue-Cured Tobacco Services, LLC.), Rotem Control & Management Systems (Britt Technical Service)

Curing Issues? Regardless if manual control or automation is utilized for curing, system inputs are still determined by grower Yellowing stage duration and at what temperature, what humidity, when to begin advancing, etc., are mainly inputs based on growers experience curing However, there can be a combination of weather and agronomic factors that results in extreme difficulty producing the desired cured leaf quality Ideal curing schedules (dry-bulb and wet-bulb temperature profiles) are going to vary each season and within a given season Curing guidelines posted on the Growers Portal

Exhaust Air Heat Recovery System Evaluation

FAN Heat Exchanger Tobacco Curing Boxes Tobacco Heated Air Intake Air Exhaust Air Heat Exchanger (recovery coil) Heat Recovery System Schematic Heat Exchanger (preheat coil)

Exhaust Vent Heat Exchanger (recovery coil) Intake Vent Heat Exchanger (preheat coil)

Single Cure Evaluated Diff. = 63 gals (17%)

Cure 7 Daily Fuel Usage Comparison (60 gallons difference)

Cure 9 Daily Fuel Usage Comparison (55 gallons difference)

Exhaust Air Heat Recovery System Average Fuel Savings – 2014 (DeCloet Barns – 10 Cures; Long Barns – 1 Cure) * Last Cure Only 52 gals (20%) 63 gals (17%)

4 Cures6 Cures

Exhaust Air Heat Recovery System Average Fuel Savings – 2015 (DeCloet Barns – 6 Cures; Long Barns – 4 Cures) 39 gals (12.3%)45 gals (16.8%)

Exhaust Air Heat Recovery System Summary Fuel savings averaged over the season for both barn makes was approximately 15% per cure (ranged 30 to 58 gallons) Curing time was not extended Burner ON/OFF cycles reduced Cured leaf was darker in the DeCloet barn with system System cost is approximately $1800 installed Simple payback at 15% savings is approximately 5 to 6 years (2015 prices, 8 cures per season) Plan to continue in 2016 – add more barns with tube-axial fan configurations

Modular Tray Steaming System – 2014

System Specifications Container dimensions: 6’ x 5’ x 10’ (300 ft 3 ) Approximately 450 trays 176 o F (80 o C) for 30 min. Steam generator with fuel oil burner – psi = 100,000 Btu/hr (420,000 Btu/hr max) – 8 to 9 gph water input – 210 to 215 o F (saturated steam)

Temperature Profiles vs. Time o F (80 o C) for 30 min.

Temperature Profiles vs. Time 176

Steaming Trays 2016 & Beyond Commercial units are probably going to be available in 2016 Growers can make their own system – 176 o F (80 o C) for 30 minutes – Btu/hr requirement will scale with container volume (350 Btu/hr per ft 3 capacity) – Insulation not required – Only the largest operations will need tray capacity – Must use steam not dry heat

Farm Safety Resources Tobacco guide will include information on Ag machinery hazards Information and links will be posted on Tobacco Growers Portal Certified Safe Farm Program National Ag Safety Database (NASD)National Ag Safety Database National Institute for Occupational Safety and Health (NIOSH)