1、A novel software-based tool to verify and predict heat treatment times for packaging wood in compliance with ISPM 15,Hugh Evans and Christine Tilbury Forest Research Emily Ho, Jenni Ferrans and Sajid Rafique BHR Group Limited,Objective,To develop a software tool to optimise the operation of industri
2、al heating chambers to comply with ISPM 15Wood packaging material should be heated in accordance with a specific time-temperature schedule that achieves a minimum wood core temperature of 56oC for a minimum of 30 minuteswith confidence minimum energy cost minimum operational time,Heating Chamber Cal
3、ibration,specific to timber species, loading and seasonal ambient temperatures: Significant air temperature variations within the chamber Significant timber temperature variations within the chamber,Current Methods of Verifying Compliance with ISPM 15,use of thermocouple probes in one or more pieces
4、 of wood Probe(s) require accurate drilling to place the tip precisely in the core of a piece of wood Probe(s) tend to be on the exposed sides of edge pieces; these receive more heat than pieces in the centre of stacked wood,precise duplication of conditions vary with time of year, wood moisture, et
5、c.,Limitations of Current Methods of Verifying Compliance with ISPM 15,Due to uncertainty, the operators tend to be over-cautious and to use longer heat treatment times as a safety margin,The Role of the Software,Software predicts heating time from basic chamber parameters including wet bulb tempera
6、tures Can be used to verify, complement or replace probe measurements Useable by chamber operators to: verify or predict heat-treatment times optimise heat-treatment times to save energy optimise chamber throughput to save time,Future Potential Developments,Use in real time control of heating chambe
7、r operation Installation of CFR 21 part 11capability allowing: Secure time stamped encrypted and inviolable data storage Electronic storage and transmission of individual chamber performance Remote interrogation by authorities of production rates Assignment of unique batch bar code allowing traceabi
8、lity of timber during transit,Thermal Diffusion Model into Wood,The core ELASTEQ model uses verified complex algorithms derived during 12 years development and use in other industries2-dimensional time-dependent model, based primarily on Ficks 2nd law of diffusion Novel six-noded quadratic triangula
9、r elements Predicts 1-dimensional or 2 dimensional heat penetration from the outside to the centre of the wood,The Model in Practice,Software uses surface temperature and diffusivity of the wood as the driving parameters for modelling core temperatureWet bulb temperature: Good indicator of surface t
10、emp of wet wood Mildly conservative indicator of surface temp of dry wood The wet bulb temperature is used as a measure of wood surface temp (with corrections for wood with low moisture content)Diffusivity depends on wood density and moisture content,Core Temperature - Wet Pine,Computed temperature
11、is a good average estimate of wet pine (39 -90% moisture content) based on wet bulb temperature,Core Temperature - Dry Pine,Computed temperature is a conservative estimate of dry pine (12 -17% moisture content) based on wet bulb temperature,Core Temperature - Wet Oak,Computed temperature is a good e
12、stimate of wet oak (54 -65% moisture content) based on wet bulb temperature,Data Input,Certification,Certification,Development and Practical Implementation,Initial use by chamber operators to check and predict heating times quarantine staff to check and verify heating times First commercial version
13、will be launched after: Beta testing of the software by potential end users Final verification in commercial situations Register now for a beta version Contact: enquiries ,The Future,A stand-alone certification tool, employing data from each HT run Network integration and encryption for remote inter
14、rogation and international traceability. This requires endorsement/approval by RPPOs and/or IPPC Next steps to address this goal: discussion with RPPOs and IPPC customise to individual RPPO requirements and local tree species,Thank you for your attention,Hugh Evans and Christine Tilbury Forest Research: hugh.evans forestry.gsi.gov.ukEmily Ho, Jenni Ferrans and Sajid Rafique BHR Group Limited: eho bhrgroup.co.uk,
