The flame structure of polyoxymethylene (POM) in the counterflow of air has been studied experimentally and numerically. The temperature distribution over a cylindrical specimen was measured with a Pt-Pt+10%Rh thermocouple. Quasi one-dimensionality of considered diffusion flame has been established experimentally, which allows analysis of flame parameters in relation to the only coordinate normal to the solid fuel's burning surface. Formaldehyde (monomer of POM) was determined to be the main product of POM thermal degradation. Flame sampling was performed with a quartz microprobe. The chemical composition of the flame was analyzed online with a mass spectrometric complex (Hiden HPR-60). The concentration profiles of the main gas flame species (CH2O, CO, CO2, H2O, O2, and N2) were measured. The chemical structure of POM-air counterflow flame was modeled by the OPPDIF code of the CHEMKIN package using the experimentally measured temperature profile and the POM burning rate. The boundary conditions on the solid fuel's surface were assigned according to the data obtained from the experiment. The results of the calculations of the chemical flame structure are in a good agreement with the experimental data. Formaldehyde was found to be decomposed in the absence of oxygen near the burning surface to form carbon monoxide, which is further oxidized to form СО2. Thus, combustion of POM decomposition products in the gas phase takes place in two macro stages, whereas usually one macro stage is used in combustion models that describe the flame propagation over polymer.

International Seminar on Fire and Explosion Hazards (9; 2019; Saint Petersburg, Russia). Proceedings of the Ninth International Seminar on Fire and Explosion Hazards [Электронный ресурс]: 21-26 April 2019, Saint Petersburg, Russia. Vol. 1 / Peter the Great St. Petersburg Polytechnic University, Autonomous Non-Profit Organization "Fire and Explosion Safety", Gefest Holding Ltd ; [edited by A. Snegirev [et al.]. — Электрон. текстовые дан. (1 файл : 118 Мб). — Saint Petersburg, 2019. — Загл. с титул. экрана. — Свободный доступ из сети Интернет (чтение, печать, копирование). — Adobe Acrobat Reader 7.0. — <URL:http://elib.spbstu.ru/dl/2/k19-45.pdf>. — <URL:http://doi.org/10.18720/SPBPU/2/k19-45>.