Temperature measurements were taken: (1) under opening scales, (2) at the seed, and (3) in the stem, of pine cones. Changes in temperature were only examined during the second stage of a two-stage seed extraction process. During this phase a permanent dehydration temperature of 50°C was used, following comparison over a ranges of temperatures, between a lower limit of 35°C and a higher limited of 50°C. The temperature was slowest to increase in the cone’s stem, and fastest to increase under opening scales. The temperature at the seed remained constant at around 43°C for the first hour of dehydration, before increasing to 50°C. The two-stages method of cone extraction employed here, with a permanent dehydration temperature of 50°C in second stage, can be used in extraction cabinets equipped with seed extractors that allow the continuous control of air humidity. The time spent soaking during the inter-stage break should last 5 minutes. Viability of seeds obtained in two-stages process was 78% to 89%
In this article, the author investigates the change of weight and temperature of pine cones in a microwave oven over the following range of microwave irradiation power (PMF): 800, 620, 440, 260 and 130 W.
Cones were divided into groups according to their weight and the author examined the influence of PMF on their water content and drying rate. The process is described with the help of mathematical equations and curves. The cones were irradiated in the microwave until all cones of the given group began to open the first scales. Small cones required longer exposure times to PMF than medium and large cones in order to cause scale opening. The most efficient of the five settings was a irradiation power of 620 W with an exposure time to microwaves for no longer than 20 seconds.
In the second part of the study, the author analyses the changes of temperature on the cone surface using a thermal imaging camera. The values of surface temperature depended on irradiation power and the duration of irradiation.
This study was conducted on a batch of closed silver fir cones from Jawor Forest District and a mixture of scales from the seed extraction facility Grotniki. The scales were divided into three size classes corresponding to the bottom, middle and upper part of the cones and their area was measured with the Multi Scan Base v.18.03 software. Based on the sum of the inner and outer surface area of all scales, we then determined the total area of evaporation from the cones. In addition, the area of protruding scales was measured for differently sized scales from different parts of the cones. Previous studies have shown that the average outer surface of a closed cone, calculated as the sum of protruding scales, accounts for 10% of the outer surface of an open cone. Pictures of both scale surfaces with the internal seed bed and the external protrusions were taken using a scanning electron microscope. We noticed significant differences in dimension and shape of the channels and trichomes on the scale surface. On the inner side of the scales, we found a high diversity of trichomes of different lengths, whilst the outer side contained channels. Presumably, these characteristics affect the rate of water loss from the cones during desiccation and separation of the seed. In-depth knowledge on the evaporative surfaces of fir cones and scale structure will be helpful for optimizing the industrial processes of seed extraction.
The article describes the shape of the cones of the european larch (Larix decidua Mill.) using the fourth degree polynomial fitting function. The material is from the seed orchard of the Barycz Forest District. The curves were used to calculate the area and volume of single cones. it was not possible to generalize the formulas to calculate the surface and volume of larch cones using the described method, due to the large variability of the empirical coefficients of the equations. Finally, to calculate the area and volume of the cones, the formula to determine the solid figure of a cone was used. A constant αs of 0.43 was introduced to the formula. Calculated volume values were compared to actual volumes measured with a water-filled burette. The mean surface area of the larch cones was calculated from the forming function and was 780 mm2, and the volume was 2434 mm3. the values calculated from the cone formulas after taking into account the αs and constants (0.68 and 0.53) were 783 mm2 and 2415 mm3, respectively. the outer and inner surfaces of the seed scales located in the central part of the larch cones were photographed using a Quanta 200 scanning microscope. Specific features of the scales were measured using the Multi Scan Base program. We found that the outer and inner surfaces of the larch scales, as with pine and fir, differed. On the outer side, scales are formed by thick-walled cells with visible, protruding trichomes. thin-walled cells with jagged cell walls are visible on the inside at the location of the wings and seeds. long stem cells, resembling threads, were observed on the surface of the scales, which are absent on pine and fir seed scales.
Every year, scaling plants buy (up to tens of tons) cones which needs to be peeled. After the process of scaling, the cones themselves are waste, which is partly sold. The problem of waste disposal is especially severe in plants where the processing is performed by electrically-powered scaling cabinets, but the problem does not apply to facilities where pellets are burned to produce beat.
We examined the beat of combustion and calorific value of the residues from scaling plants that can be used in the production of refined wood fuels. The residues consist of the empty cones of pine, spruce, larch as well as husks and stems of silver fir. Additionally, we conducted measurements of the beat of combustion for wood and cones of each species and compared them to their respective calorific values.
The results revealed that the average calorific value of the cones is in the range 17.81-19.86 MJ/kg. Our work showed that empty cones have a significantly higher calorific value and beat of combustion than the wood of spruce, larch and fir. In the case of pine, cones and wood did not differ significantly.
These results led us to the conclusions that empty de-scaled cones can be utilised as a valuable primary solid fuel or fuel additive for the production of refined products for the local market.
Due to the low annual production of cones in comparison to other materials such as sawdust and wood chips, pine cones should be used as a supplement, to enrich fuels of inferior quality by enhancing their energetic properties.
This study aimed at determining the shape of closed silver fir cones from the Jawor Forest District (Wroclaw), based purely on measurements of their length and thickness. Using these two parameters, the most accurate estimations were achieved with a fourth-degree polynomial fitting function. We then calculated the cones’ surface area and volume in three different ways: 1) Using the fourth-degree polynomial shape estimation, 2) Introducing indicators of compliance (k1, k2, k3) to calculate the volume and then comparing it to its actual value as measured in a pitcher filled with water, 3) Comparing the surface area of the cones as calculated with the polynomial function to the value obtained from ratios of indicators of compliance (ratios k4 and k5). We found that the calculated surface area and volume were substantially higher than the corresponding measured values. Test values of cone volume and surface area as calculated by our model were 8% and 5% lower, respectively, compared to direct measurements. We also determined the fir cones apparent density to be 0.8 g·cm-3on average. The gathered data on cone surface area, volume and bulk density is a valuable tool for optimizing the thermal peeling process in mill cabinets to acquire high quality seeds.
Fir cones Abies alba Mill. are not as extensively described in the literature as cones of other species, and therefore, there is no description of the changes in water content and their dynamics during the extraction process. Developing a mathematical model describing these changes based on cone parameters and air temperature is a step forward in determining the optimal conditions for the extraction process. here, we present such a model derived using fresh cones collected in a seed production stand in the Zwoleń Forest District (RDSF Radom). For 120 randomly chosen cones, the length and the largest diameter of the cone were measured, using the Multiscan program. in addition, for 60 randomly selected cones, the diameter was measured along the entire length of the cone at 10 mm intervals. this allowed us to generate cone models approximating rotational solids for which the outer surface area was calculated using a fourth degree polynomial function and the obtained area was then used to determine cone volume. to facilitate the generalization of surface area and volume calculations to other cones, the ks1 and ks2 coefficients were derived, which simplified the employed formulas without significantly affecting accuracy.
Analogous analyses were also performed for cone stems, which allowed the process of seed extraction from cones to be described by mathematical equations. The stem of the cone was found to constitute 2.6% of its volume and 4% of its dry mass. An exponential equation was used to describe the change in cone mass during the seed extraction process, in which the parameters are the initial and final water content of the cone and power factor b, which is a function of cone thickness. The energy content and germination rate for the extracted seeds were determined 14 and 28 days after sowing. The seeds obtained in the investigated extraction process did not reach first grade quality.