Sudsakorn Inthidech

Effect of filter media size, mass flow rate and filtration stage number in a moving-bed granular filter on the yield and properties of bio-oil from fast pyrolysis of biomass.

Fast pyrolysis of cassava rhizome was performed in a bench-scale fluidised-bed reactor unit incorporated with a cross-flow moving-bed granular filter. The objective of this research was to examine several process parameters including the granular size (425-1160 μm) and mass flow rate (0-12 g/min) as well as the number of the filtration stages (1-2 stages) on yields and properties of bio-oil. The results showed that the bio-oil yield decreased from 57.7 wt.% to 42.0-49.2 wt.% when increasing the filter media size, the mass flow rate and the filtration stage number. The effect of the process parameters on various properties of bio-oil is thoroughly discussed. In general, the bio-oil quality in terms of the solids content, ash content, initial viscosity, viscosity change and ageing rate could be enhanced by the hot vapour granular filtration. Therefore, bio-oil of high stability could be produced by the pyrolysis reactor configuration designed in this work.

Two body type abrasion wear behaviour in hypoeutectic 16%Cr cast irons with Mo

Abstract Hypoeutectic 16%Cr cast irons, both Mo free and 1–3%Mo containing specimens were prepared to investigate their abrasion wear behaviour. Annealed specimens were hardened at 1323 K and then tempered at three temperatures from 673 to 873 K for 7·2 ks, the temperature giving the maximum hardness (HTmax) and the lower and higher temperature, (L-HTmax, H-HTmax). The abrasion wear behaviour was investigated using a two body type Suga abrasion wear tester. A linear relation was obtained between wear loss and wear distance. The highest wear resistance or the lowest wear rate (R W) was obtained in H Tmax specimens except for the Mo free specimen. The lowest wear resistance or the highest R W was obtained in H-HTmax specimens. The R W was decreased with an increase in macrohardness. The lowest R W appeared around 25% retained austenite (V γ ). The R W was decreased with an increase of Mo content, and the V γ value at the minimum R W shifted to the high V γ side.

Effect of molybdenum content on subcritical heat treatment behaviour of hypoeutectic 16 and 26 wt-% chromium cast irons

Abstract Hypoeutectic high chromium cast irons containing 16 and 26 wt-%Cr, with and without Mo, were prepared to clarify the variation of hardness and volume fraction of retained austenite (Vγ) during subcritical heat treatment. As cast specimens were held at temperatures between 773 and 973 K for 21··6 ks (6 h) and air cooled with a fan. Hardness and Vγ values were measured in all specimens. In the subcritically heat treated state, secondary hardening similar to hardened tempered alloy cast irons and steels was observed. Vγ decreased gradually with rising temperature. The maximum hardness levels following subcritical heat treatment were obtained at temperatures between 823 and 873 K. The greatest improvement, an increase of 140 HV30, was obtained in 16 wt-%Cr cast iron with 3 wt-%Mo.

Effect of Sub-Critical Heat Treat Parameters on Hardness and Retained Austenite in Mo-Containing High Chromium Cast Irons

Subcritical heat treatment of austenite in alloyed cast iron, treated at a temperature below pearlite transformation (A1), has been used to improve matrix hardness without conventional hardening heat treatment. Two series of hypoeutectic 16 and 26 wt% Cr cast irons containing 0, 1, 2 and 3 wt% molybdenum (Mo) were used to investigate the behavior of hardness and retained austenite during subcritical heat treatment. An as-cast test piece was held at subcritical temperatures in 50K intervals from 773K (500C, 932F) to 873K (600C, 1112F) for 21.6 ks to 64.8 ks and then cooled to room temperature by fan cooling. Hardness and volume fraction of retained austenite (Vγ) were measured. In the as-cast state, the hardness decreased gradually but the Vγ increased greatly as Mo content increased in both 16 and 26 wt% Cr cast irons. In the state of subcritical heat treatment, the hardness increased first and then decreased with an increase in holding time. This phenomenon is due to a hardening caused by the precipitation of secondary carbides and by martensite transformation from the destabilized austenite during cooling. At the same Mo content, the degree of hardening was greater in the 16 wt% Cr cast iron than in the 26 wt% Cr cast iron. The Vγ decreased with an increase in both holding time and holding temperature. The maximum hardness in the subcritical heat treatment (HSTmax) was obtained when the specimens were treated at temperatures from 823K (550C, 1022F) to 873K (600C, 1112F) for 50.4 ks. The HSTmax increased gradually in the 16 wt% Cr cast iron but it changed little in the 26 wt% Cr cast iron when Mo content was increased. The highest value of HSTmax, 760 HV30, was obtained in the 16 wt% Cr cast iron with 3 wt% Mo where the Vγ was less than 10%.

Design Optimization of Cutting Parameters when Drilling Metal Matrix Composites

The Taguchi method is used to find the optimal cutting parameters when drilling metal matrix composites (MMCs) with a polycrystalline diamond (PCD) tool. The combined effects of cutting parameters (cutting velocity and feed rate) and cutting time on three performance measures (tool wear (VBmax), the specific cutting pressure (Ks) and hole surface roughness (Ra)) were investigated employing an orthogonal array, signal to noise (S/N) ratio and the analysis of variance (ANOVA). The optimal cutting parameters for each performance measure were obtained, and the main cutting parameters that affect the cutting performance in drilling operations can be found. The relationship between the drilling parameters and the performance measures were determined using multiple linear regressions. Confirmation tests of the optimal levels with the initial machining parameters are carried out in order to illustrate the effectiveness of this approach for drilling MMCs.