There was no change to the moisture content of any of the western hemlock log sample sets during the study period between 1 Dec 2014 and 5 mar 2015. It seems that this lack of change is related to stability in environmental humidity experienced by the logs. Whether or not time since cutting influences the ability of Hw logs to change moisture content could not be conclusively determined by the study.
PDF
Ajoutez cet article à votre liste de sélections pour demander le PDF - Add this item to your selection list to request the PDF
Based on the data from this study and a literature review, there are two distinct trajectories for hemlock wood moisture content, depending on if the tree was felled before or after May. Hemlock trees felled before May gain the full benefit of spring drying according to the ambient conditions of their local micro-climate. Trees felled after May suffer from a physiological spike in moisture content that the tree generates to promote its growth and survive the summer soil drought.
The problem of second-growth western hemlock (Tsuga heterophylla) sinking when watered continues to plague the coastal logging industry of British Columbia. A study conducted by FPInnovations in 2015-16 concluded that felled hemlock logs took two distinct trajectories in their drying patterns through time, depending on whether they were felled before or after May.
One of the challenges to the use of biomass in heat applications is to find a suitable technology to take quick and accurate moisture content (MC) measurements of comminuted forest biomass. In this study, we tested three difference technologies (electric, nuclear and infrared) and five different tools. Of the three technologies tested, electric is the most promising. It is usually inexpensive (<$1000), requires small-sized samples (10 L), is fast to read (<1 minute) and is relatively accurate with more than 70% of measurements within 5% MC of the oven-dried method.
BIOMASS
MOISTURE CONTENT
TECHNOLOGY
ELECTRIC ANALYZERS
NUCLEAR RADIATION
INFRARED DETECTORS
ACCURACY
MEASUREMENT
TIME
Sample size
Abstract
L’une des difficultés associées à l’utilisation de la biomasse forestière broyée pour produire de la chaleur consiste à trouver une technologie convenable pour prendre rapidement des mesures précises de la teneur en humidité (TH). Pour la présente étude, nous avons mis à l’essai trois technologies (électrique, nucléaire et infrarouge) et cinq appareils différents. Parmi les trois technologies, c’est la technologie électrique qui est la plus prometteuse. Les appareils sont généralement peu coûteux (< 1000 $), nécessitent des échantillons de petite taille (10 L), donnent les résultats rapidement (<1 minute) et sont relativement précis, plus de 70 % des mesures se situant à plus ou moins 5 % de la TH obtenue par la méthode de séchage à l’étude.
. ........................................................................................ 5
Figure 3. Disc samples to determine the initial moisturecontent in January 2012
The effects of natural drying in relation to the use of tarps on the moisture content of stacked softwood roundwood were examined. Biomass quality logs were stored for a period of 15 months in a mill yard in the Bas Saint-Laurent region of Quebec. The results of the study showed that the roundwood dried naturally during the summer season with moisture content at the end of the season below 30%. Tarping the roundwood piles during the fall and winter prevented an average increase in moisture content of 6%.
Abstract
Cette étude d'entreposage de la biomasse forestière visait à évaluer les effets du séchage naturel par rapport à l'utilisation de bâches sur la teneur en humidité de bois rond résineux au cours d'une période de 15 mois. Des billes de qualité biomasse ont été empilées dans un parc d'usine de la région du Bas-Saint-Laurent, au Québec. Les résultats de l'étude ont démontré que la biomasse séchait très bien naturellement pendant l'été avec un taux d'humidité en fin de la saison estivale en-dessous de 30%. La bâchage des empilements de biomasse au cours de l'automne et de l'hiver a permis d'éviter une augmentation moyenne du taux d'humidité de 6 %.
One of the challenges to the use of biomass in heat applications is to find a suitable technology to take quick and accurate moisture content (MC) measurements of comminuted forest biomass. In this study, we tested three difference technologies (electric, nuclear and infrared) and five different tools. Of the three technologies tested, electric is the most promising. It is usually inexpensive (<$1000), requires small-sized samples (10 L), is fast to read (<1 minute) and is relatively accurate with more than 70% of measurements within 5% MC of the oven-dried method.
Hemlock can have higher moisture content than most other native trees, causing them to sink. Hemlock lumens have large pits (valves) that allow easy transport of water into the wood.
Bigger rings = bigger lumens. Younger hemlock or hemlock tops are more susceptible to sinking. The bigger the rings the more likely to take on water.
FPInnovations performed short-term productivity studies on a road rehabilitation operation that utilized a Kobelco ED150 BladeRunner. The BladeRunner is a multi-purpose machine that can function as an excavator and a bulldozer, due to its front blade attachment. Productivity studies were also performed on an excavator (John Deere 200C) and bulldozer (Caterpillar D6M) team that performed the same work as the BladeRunner.
ROADS
MACHINERY
HARVESTERS
Abstract
FPInnovations a effectué des études de productivité à court terme dans le cadre d’une opération de remise en état de routes effectuée à l’aide d’un BladeRunner, modèle Kobelco ED150, une machine multifonctions qui peut être utilisée comme excavatrice ou bulldozer en raison de sa fixation frontale pour lames. Des études de productivité ont aussi été réalisées sur une combinaison excavatrice (John Deere 200C) et bulldozer (Caterpillar D6M) qui effectuent les même tâches que le BladeRunner.
During June and July 1989 FERIC understock a project to determine the extent of moisture loss in felled trees in East-Central Alberta. This project was funded by Alberta Forestry, Lands and Wildlife and Alberta-Pacific Forest Industries.
