Lower Final Moisture Content Research Articles

An investigation into an improved method of fine coal dewatering

An improved method of dewatering fine coal (−500 μm) by vacuum filtration was developed. Tests on a bench scale vacuum filter showed that when the applied vacuum was interrupted during the dewatering cycle, a lower final moisture content could be achieved. There was also an increase in the dewatering rate, as well as a lower breakthrough pressure. Further investigation showed that if the filter cake was intentionally damaged (causing for an increased air flow rate, and a decrease in applied vacuum), a product with lower final moisture and an increase in the dewatering rate was obtained. This led to the conclusion that increased air flow through a filter cake was more advantageous than an increase in the applied vacuum.

Industrial Kiln Drying and its Effect on Microstructure, Impregnation and Properties of Scots Pine Timber Impregnated for Above Ground Use. Part 1. Effects of Initial, Final Dryings and Preservative on Impregnation and Timber Quality

Summary Scots pine (Pinus sylvestris L.) planks were dried in industrial progressive, conventional batch and high temperature kilns. The quality of drying was assessed by measuring the final moisture content and its gradient, deformations, checks and internal stress of planks. The timber was rearranged in three charges and impregnated in an industrial autoclave with copper-based preservatives for above ground use (class AB):Kemwood ACQ 1900, Tanalith E and Wolmanit CX-8. The moisture content was determined after impregnation and the planks were divided into two charges; the first was dried in an industrial conventional batch kiln while the second was air dried. Assessment of the final product quality after kiln and air drying was carried out as after the initial drying. The penetration of preservatives was measured as well. The data were analysed by a statistical mixed model to ascertain the effects of drying and preservatives on the impregnation and timber quality. A strong relationship was found between the initial drying of Scots pine timber and its quality after impregnation and drying. The conventional batch and high temperature kiln drying ensured similar drying quality regarding the final moisture content and gradient, bow, twist and checks, but the high temperature drying provided significantly better (94.4%of the total sapwood area) penetration of the preservatives tested. It is suggested that changes in wood structure could be provoked during the high temperature drying, thus improving the subsequent impregnation and secondary drying. The progressive and conventional batch kiln drying led to similar penetration of the preservatives; the conventional batch kiln drying ensured significantly lower final moisture content, less twist and surface checks of the timber than the progressive kiln drying. Wolmanit CX-8 penetrated significantly better into the pine sapwood (96.3%) than Kemwood ACQ 1900 and Tanalith E (83.5 and 88.5%, respectively). The planks impregnated with Wolmanit CX-8 achieved the best quality regarding the final moisture content, its gradient and cup. The planks impregnated with Kemwood ACQ 1900 and Tanalith E showed similar quality regarding the penetration and some deformations after drying, but Kemwood ACQ 1900 impregnated planks had highest moisture content and gradient.

Influence of humidity on production of pelleted fungal inoculum

One of the practical problems in scaling-up the production of fungal inocula for environmental applications is how to provide essential humidity for fungal growth. Pelleted solid substrate was used as a fungal biomass carrier. It was coated with alginate or agar hydrogels that contained mycelial fragments of the white-rot fungi Trametes versicolor or Irpex lacteus. To follow fungal growth and formation of mycelial coat over pelleted substrate, the fluorescein-diacetate hydrolysing activity (FDA) assay and visual inspection were used. Both fungi were able to overgrow the pelleted substrate in 5–6 days, at a relative humidity (RH) of 86.3% or higher. The enrichment of alginate hydrogel with nutrients or coating of pelleted substrate with more hydrophilic agar hydrogel enabled I. lacteus to overgrow the pellets at a lower RH of 83.6%. Fungal inocula produced at lower RH possessed lower final moisture contents and had greater mechanical strength. Conditioning of T. versicolor mycelial fragments, by a 3-h incubation in fresh growth medium, enhanced fungal growth over the pelleted substrate. A mathematical model was used to simulate and to explain moisture distribution in a hydrogel-coated pellet and the formation of mycelial coat, for various conditions of fungal inocula production.

Moisture content of the dried leaf is critical to desiccation tolerance in detached leaves of the resurrection plant Boea hygroscopica

In our experimental conditions detached leaves of the resurrection plant Boea hygroscopica survived equilibration to 65–80% RH (Relative Humidity), but not to very low RH (close to 0%). The first aim of our research was to determine whether sensitivity to equilibration to very low RH depends on the rate of the drying process or on the very low final MC (Moisture Content) attained. The second aim of our research was to determine ABA content of leaves exposed to the two drying processes: a first step towards understanding whether ABA is involved in the tolerance mechanism of Boea hygroscopica.

Hochtemperaturtrocknung von frisch gesägtem Pappelholz in einem Umlufttrockner

The special interest in Europe for the properties and the use of poplar and its hybrids, especially for the wood technological properties and their effect on the industrial processing of poplar wood, as well as the growing need for fast drying processes producing wood with a low final moisture content, led to this study. It was to be investigated whether high temperature drying (HTD) could also be applied to light hardwoods with properties similar to that of softwoods, like e.g. poplar. Poplar has some peculiar properties, e.g. large heterogenity, wet pocket formation, tension wood, juvenile wood., ..., complicating the application of HTD and increasing the risk for drying defects. Eleven different high temperature drying schedules and one low temperature drying schedule were performed in an experimental electrical drying oven on piles of small sizes of fresh poplar. For reference, five piles of fresh poplar were subjected to accelerated air-drying. Equations were obtained from two seperate multivariate regression analyses with wood characteristics for the first and typical drying-schedule parameters for the second regression, as independent variables, and a number of quantified drying defects as dependent variables for both regressions.

Operating Conditions for Drying Paddy in a Rotating Drum with Sand Medium

ABSTRACT Batches of wddv rewened to 18% or 24% moisture content were dried in a sealed rotating drum containing ; preheated sand. For each initial moisture content, all combinations of the following variables were replicated three times: sand patilcle size (0.3 and 0.6mm). residence time (60, 120 and 180 s), sand-to-grain mass ration ( 3:1, 6:1 and 9:1) and initial sand temperture ( 100, 150 and 200°). The dried paddy was shelled and milled and the percentage of whole grain kernels was determined. In general. the paddy starting at 18% mc led to lower final moisture contents than that starting at 24%. For equivalent final moisture contents, milling yields of whole rice were equivalent. Best yields were generally associated with lower energy input (ie. low to intermediate initial sand temperature and sand-to-grain mass ratios below 4.7:1) Residence time was not critical in determining milling yieid. This study indicates that particulate medium drying of paddy is an interesting alternative to traditional dry...

Coprophilous mite communities as affected by concentration of plastic and glass particles

The community and trophic structure of mites was examined in cattle manure and their response to treatment of manure with solid-waste particles was investigated. Mites were collected from artificial dung pats exposed to natural colonization in the field for 16 days. The pats were composed of manure alone or manure separately mixed with waste-material particles of four types and concentrations. Mites were the numerically dominant taxon among arthropods in manure. The Prostigmata was the most abundant suborder, mainly represented by the families Pygmephoridae and Ereynetidae. The common families of Mesostigmata were all cosmopolitan. Correlations with other arthropods suggest that Mesostigmata are opportunistic predators, preying upon dipteran larvae, Collembola and other mites, and preyed upon by larger predatory insect larvae. Cryptostigmata and Astigmata were a numerically minor community component. The species composition and abundance upon treatment of manure with polyethylene, polystyrene and glass particles was similar to that of the treatment control, i.e. natural and inert sand. Relatively low concentrations, 5 and 30% (v/v), of particles in manure did not alter the mite communities despite important differences with untreated manure in final moisture content. These findings may be relevant to proposed methods of solid-waste disposal. High particle concentrations of 60 and 90% had detrimental effects to the abundance of mites in manure and were caused by the very low final moisture content and probably nutrient deficiency of these treatments. The persistence of members of the prostigmatid families Tydeidae, Nanorchestidae and Tarsonemidae in the moisture-deficient 90%-concentration treatments supports previous evidence of adaptations to low-water-content habitats.

Some Results of Storage Tests on Farmers Stock Peanuts

Abstract Storage tests were conducted on farmers stock peanuts during three seasons. The peanuts were aerated with 1/20 and 1/10 cubic feet per minute (cfm) of air per cubic foot of peanuts when the incoming air was within certain ranges of relative humidity. The aeration was beneficial in maintaining the desired peanut moisture content level and in preserving desirable milling characteristics. Attempts to maintain a lower temperature within the peanuts were unsuccessful. Peanuts near the bin walls and in the top layers had higher average temperatures, lower final moisture content levels, lower germination, and more split kernels than peanuts stored in other locations within the bins.