1. THE EFFECT OF TASK AND SONIC TREATMENT ON THE TREATABILITY OF DOUGLAS FIR AND SOUTHERN PINE HEARTWOOD Mike Barnes, Mississippi State University and John Simonsen, Oregon State University College of Forestry Oregon State University

2. FLOW DURING TREATMENT P inside  P = P outside - P inside P outside

3. DARCY’S EQUATION A flow L P1P1 P0P0

4. PRESSURE DIFFERENTIAL  Hydraulic pressure –gear pump –piston pump –air compressor

5. SONIC WAVE FREQUENCY = 20 CYCLES/SEC

6. SCHEMATIC OF TREATMENT PROCESS Cylinder: 18” X 10’ Fill tank MTS sonic generator Gauge tank Fill and drain pump Solenoid valve Level sensor Computer control and data recording Vacuum pump Air pressure

9. TREATMENT CHARGE  Sample = 2X4 (9pine), or 2X6 (fir)- 2’  Ten samples each charge  Weigh each sample before and after  Adjust for uptake while filling  Matched samples for sonic and conventional

10. EXPERIMENTS COMPARING AVERAGE PRESSURE  We performed experiments comparing treatments at the same average pressure, but with a sonic pressure wave superimposed on the the conventionally applied (air in the gauge tank) pressure  In this case, the average sonic pressure is zero

11. EXPERIMENTS COMPARING AVERAGE PRESSURE Air pressure sonic pressure conventional sonic pressure 0 psi 70 psi  50 psi

17. Comparing treatments at the peak pressure  Treating plants must be designed to withstand the maximum pressure, not the average pressure. Thus we performed experiments comparing the pressure at the peak of the sonic wave vs. the same pressure for conventional treatment.

18. COMPARISONS AT PEAK PRESSURE Air pressure sonic pressure conventionale ntional sonic pressure 0 psi 60 psi 100 psi

21. CONCLUSIONS  Sonic treatment not effective on pine or fir  TASK treatments effective on fir, but not pine  Comparison at peak pressures shows sonic treatment less effective than conventional treatment

22. PLANS FOR THE FUTURE  Higher frequencies, pressures  Hybrid hydraulic/sonic treatment  Cooperative study on Douglas- fir with MSU  Southern pine heartwood  Other refractory species