World experience shows that family farms are the basis for the agricultural sector of countries with advanced market economies. The analysis of the components of the livestock ration provided an opportunity to identify the amount of feed mixture, which needs to be distributed to animals per day, depending on the livestock. Researches have shown that for preparation and distribution of feed on farms with livestock up to 10 cattles, it is advisable to use inefficient machinery with energy drive and partial execution of manual operations, 11-35 -self-feeders, mechanized lines using stationary machinery with energy drive and forklifts. For 36-50 cattles of livestock and at an average animal productivity of at least 6500 kg of milk per year, processes of preparation and distribution of feed can provide self-feeding and mobile combined feed making machines. Preparation and distribution of feed mixes for 51-400 heads of cattle -provide mobile combined feed making machines with delivery of the mixture on the feed tables. For livestock with more than 400 heads of cattles, it is advisable to use stationary robotic feed making facilities and distributors of feed mixtures or a mobile combined feed making machine. In the feed mixture preparation process, it was found that the multifunctional feed making machines with a vertically positioned conical auger in the hopper have a high power consumption of more than 35 kW. Power consumption, driven by the working bodies, is almost directly proportional to the speed of an auger. With increasing rotation frequency of an auger, the efficiency of grinding and mixing does not increase significantly; we have substantiated the rotation frequency of an auger 16-20 min -1 , with grinding rolls and packs and in the mode of mixing and dispensing 24-25 min -1 . However, in the process of dispensing the feed mixture, the existing auger does not clean itself from the feed.
The reasons of white spots appearance in the middle of oak timber are determined. These white spots reduce the cost of the lamina made of oak timbers - the front covering of floorboards. It is proposed to intensify the drying process by using oscillating drying schedules to avoid this defect. A method for calculating the duration of such drying is proposed. This method includes the peculiarities of heating and cooling periods kinetics of oak timbers with 25 mm and 30 mm thickness. The inexpediency of using the oscillation of the drying agent parameters in the range of wood moisture content below 20% has been established. An adequate model for calculating wood temperature and air humidity during wood heating and cooling periods has been developed using heat and mass transfer criteria and experimentally determined oak wood moisture conductivity coefficient. Based on the results of theoretical and experimental studies oscillating drying schedules of different thickness oak timbers are offered. Tests of the proposed schedules in industrial conditions showed no discoloration of the central layers of European oak (Quercus robur) timbers. The drying process duration was reduced by 1.5–2.4 times and energy consumption were reduced by 1.53 times.
The reasons for the reduction in the price of the lamella made of oak wood have been determined. It is established that during the drying of oak wood at low temperatures there is an accumulation of moisture in the near-surface zone, the so-called “conditional source of moisture”. This leads to the formation of light spots in the middle of the lumber, which have long been in conditions of high air humidity and had a low rate of moisture removal. To avoid this defect, it is proposed to intensify the drying process by using oscillating schedules, which consist of periods of heating and cooling of wood. During the heating period, the temperature of the material gradually rises, the wood receives heat stroke and accumulates heat, drying occurs only due to the moisture gradient. During cooling, the air temperature decreases, the degree of saturation increases and, accordingly, the equilibrium moisture content increases. As a result, the surface layers of the material are moistened, the moisture is leveled along the thickness of the wood, there is a relaxation of drying stresses. In the laboratory, experimental studies of oscillating drying of red oak wood blanks with a thickness of 30 and 50 mm were performed. The amplitude of temperature fluctuations is determined - 30 ° С and the expediency of cyclic heating only until the average moisture content of the material reaches 20%, after which the wood should be dried to the required final moisture content at a constant heating temperature. A method for calculating the duration of oscillating drying is proposed, which takes into account the peculiarities of the kinetics of the periods of heating and cooling of sawtimbers made of red oak wood with a thickness of 30 mm and 50 mm. It is recommended to consider the process of temperature change kinetics as the sum of the processes of cyclic heating, which occurs in polynomial dependence, and cyclic cooling, which occurs in exponential dependence. It is determined that the ratio of the duration of cyclic heating to the duration of cyclic cooling is 1/3. Using heat and mass transfer criteria and the experimentally determined coefficient of moisture conductivity of red oak wood, an adequate model for calculating wood temperature and relative humidity during wood heating and cooling cycles has been developed. Based on the obtained results of theoretical and experimental studies, oscillating drying schedules of red oak blanks of different thickness are proposed, which exclude the formation of white spots in the middle of the material. The process was reduced by 1.5–2.4 times and energy consumption was reduced by 1.53 times. Experimentally determined indicators of residual stresses, the magnitude of the stress difference in the workpieces after drying and the values of the tensile strength showed that the quality of drying corresponds to the I quality category according to DSTU 4921: 2008. Comparison of the obtained values with the maximum allowable values of tensile strength across the fibers in the tangential direction σm = 6.5 MPa showed a margin of safety - 25%, which indicates the possibility of using oscillating drying schedules for high-quality drying of red oak wood blanks. Keywords: Red oak (Quercus rubra), moisture conductivity coefficient, oscillating schedules, drying quality, drying duration.
The article analyzes the physical ways to provide the necessary limit of fire resistance of wooden structures, which have significant disadvantages, namely, leading to significant material costs and increase the volume of structures. Modern methods of fire protection of building structures are based on the use of blocking coatings, which are complex systems of organic and inorganic components. Studies of the combustibility of wood have shown that a raw specimen of timber construction is capable of engaging and spreading flames on the surface. Instead, the structure treated with the organo-mineral protective coating did not burn after combustion of the model hearth, respectively, and did not break down. The swelling of the protective coating was recorded, and the temperature on the reverse floor was less than 140ºC. As a result, it was ascertained that the effectiveness of the shredded image of the tree’s construction was 4.4 times higher for the protected organic and mineral coatings 3.3 times higher - for the clear protection of non-organic ones. It’s necessary to assimilate a coke ball on the surface of the construction, which will add to the temperature and the temperature glyphine, with which the hour of reaching the boundary temperature will be improved.
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