A novel method for analyzing grain facility heat treatment data. Hulya AKDOGAN Mark CASADA Alan DOWDY Bh. SUBRAMANYAM

Transcription

1 A novel method for analyzing grain facility heat treatment data Hulya AKDOGAN Mark CASADA Alan DOWDY Bh. SUBRAMANYAM

2 A novel method for analyzing grain facility heat treatment data ~ Introduction ~ Management of Stored Product Insects (SPI) in grain processing facilities (chemical methods versus high temperatures) 1 Heat treatment - a viable alternative to chemicals Target temperature 5 o C, typically 5 o to 6 o C Temp., duration of exposure, species, stages of development, RH determines insect survival.

3 A novel method for analyzing grain facility heat treatment data ~ Materials/Methods (1/2) ~ 2 Pilot flour mill & cleaning house at KSU (6/99 & 8/99) Two heating systems: gas & electric Gas heating: heaters outside the building; hot air delivered inside the building through nylon ducts Electric heating: heaters within the building; power & monitoring cables running outside the building Fans used for uniform temperature distribution Time/temperature/RH recorded every 1 min at floor level; data loggers per room.

4 A novel method for analyzing grain facility heat treatment data ~ Materials/Methods (2/2) ~ Effectiveness of heat treatments compared by surface area method 3 Surfer software used to calculate the surface areas % floor surface area < 5 o C as a function of time (duration of the heat treatment) and % floor surface area maximum floor temperature Contour maps of maximum floor temperature

5 A novel method for analyzing grain facility heat treatment data ~ Results ~ Different heating patterns 4 Lag times (time delays) 25 2 Gas heating Electric heating Lag time (h) Mill 2 Mill 3 Mill 4 CH 1 CH 2 CH 3 CH 4 Entire facilty Location

6 5 Floor surface area < 5 C (%) Mill Flour Mill Duration of treatment (h) Red- electric heating Black- gas heating

7 A novel method for analyzing grain facility heat treatment data ~ Results ~ 6 The surface area approach Surface areas calculated from Surfer outputs Normalized % surface area values for easy comparison A norm = A( t) A f A i A i A norm is the nondimensional area under 5 C A(t) is the percent area < 5 C at time t A i is the % area < 5 C at the beginning of heat treatment A f is the % area < 5 C at the end of heat treatment. Nonlinear regression - PROC NLIN procedure (SAS)

8 A novel method for analyzing grain facility heat treatment data ~ Results ~ 7 The surface area approach (ctd.) A log-logistic equation used: Percent Surface Area = 1+ e b (( temperature) c) log 1 Pseudo-R 2 calculated. Ranged from Pseudo R = 1 SSR SST SSR= Residuals Sum of Squares SST=Total Sum of Squares 1

9 8 Duration of treatment vs. % floor surface area < 5 C 1 Cleaning house Cleaning house 2 1 Mill Surface area under 5 o C (%) Cleaning house Mill Cleaning house 4 1 Mill Treatment time (h)

10 Flour Mill 4 9 Floor surface area < 5 C (%) Mill Duration of treatment (h) Red-electric heating Black-gas heating

11 Cleaning house 1 1 Floor surface area < 5 C (%) Cleaning house Duration of treatment (h) Red-electric heating Black-gas heating

12 Cleaning house 4 11 Floor surface area < 5 C (%) Cleaning house Duration of treatment (h) Red-electric heating Black-gas heating

13 Max. floor temp. vs. % floor surface area 12 1 Mill 2 Mill 2 8 Surface area (%) Temperature ( o C) red-electric heating black-gas heating

14 A novel method for analyzing grain facility heat treatment data ~ Results ~ 13 Time delays (lag times) Gas heating slower at the beginning Electric heating mostly shorter compared to gas heating Effectiveness of treatment (T<5 o C) Gas heating less under-heated areas observed Electric heating more under-heated areas observed

15 A novel method for analyzing grain facility heat treatment data ~ Maximum temperature distributions ~ 14 TempAir North Gas heating Cleaning house Mill Floor 4 Floor 3 Floor 2 Floor C Cleaning house Electric TecHeatheating Mill 6 C 55 C Floor 4 5 C 45 C Floor 3 Floor 2 Floor Flour mill 1 was not studied.

16 15 Gas heating Cleaning house house Flour mill N> Floor 4 85 C 8 C 75 C Floor 3 7 C 65 C 6 C 55 C Floor 2 5 C 45 C 4 C Floor 1

17 16 Electric heating Cleaning house Flour mill N> Floor 4 85 C 8 C 75 C Floor 3 7 C 65 C 6 C Floor 2 55 C 5 C 45 C Floor 1 4 C

18 A novel method for analyzing grain facility heat treatment data ~ Main points ~ 17 Heat treatment as an alternative to chemical treatments Different heating patterns of gas and electric heating-time delays; % A under/over-heated Sufficient heat treatment & uniform heat distribution Quantification & identification of over-heated & under-heated areas Characterizing the heating pattern of each method via modeling (log-logistic eqn.)

19 Thank you The End