Studies show value of forced air ventilation for potato storages

1960 ◽  
Vol 37 (5) ◽  
pp. 182-185
Author(s):  
James Hunter
Keyword(s):  
Air Ventilation ◽  
Forced Air

Thermal analysis of forced-air and thermosyphon cooling systems for the Inuvik airport expansion

1991 ◽  
Vol 28 (3) ◽  
pp. 399-409 ◽  
Author(s):  
L. B. Smith ◽  
J. P. Graham ◽  
J. F. Nixon ◽  
A. S. Washuta
Keyword(s):  
Thermal Analysis ◽  
Natural Convection ◽  
Key Words ◽  
Thermal Analyses ◽  
Cooling Systems ◽  
Air Ventilation ◽  
Forced Air ◽  
Department Of National Defence ◽  
Raft Foundations ◽  
National Defence

This paper presents a description of thermal analyses of forced-air ventilation and thermosyphon cooling systems, which were carried out in connection with the design of the concrete raft foundations that support hangars and other major structures to be constructed by the Department of National Defence adjacent to the existing airport near Inuvik, N.W.T. The cooling systems are required to prevent heat from the buildings from thawing the ice-rich permafrost present below the site. The analyses identified those parameters that have the most significant effect on the efficiency of each system. Based partially on the results of the analyses, it was decided to utilize air ventilation for cooling. The system is expected to perform satisfactorily under natural convection; however, the design includes a provision to install air blowers, if this should prove necessary in the future. A number of areas in which further research appears useful have been identified. Key words: permafrost, thermal analysis, raft foundation, hangar, ventilated slab, natural convection, thermosyphons.

First Canadian Geotechnical Colloquium: Foundation design approaches in permafrost areas

1978 ◽  
Vol 15 (1) ◽  
pp. 96-112 ◽  
Author(s):  
J. F. Nixon
Keyword(s):  
Influence Factors ◽  
Frozen Soil ◽  
Case Histories ◽  
Foundation Design ◽  
Large Structures ◽  
Theoretical Predictions ◽  
Air Ventilation ◽  
Insulation Thickness ◽  
Forced Air

The design of foundations in permafrost areas for large structures involves a knowledge of the thermal and mechanical properties of frozen soil. Recent creep data for frozen soils and ice are reviewed and some secondary (steady) creep relationships are established. A design approach for pile foundations in ice-rich permafrost is proposed and compared with available field case histories. The theory is found to provide reasonable predictions of pile settlements under load. It is suggested that the limitation of long-term pile settlements will control the design loadings.The thermal aspects of ventilated pad foundations are discussed and design curves are given for required pad and insulation thickness and ventilation capacity. Case histories indicate that in order to obtain the necessary ventilation capacity, forced air ventilation using electric fans is required for most practical situations.A settlement analysis for spread footings on permafrost is established and influence factors for settlement rate are given. Again it is apparent that allowable footing loads will be controlled by limiting long-term settlements, rather than by consideration of soil shear strength alone. Field data on the creep response of a tunnel in Fairbanks provide good correlation with theoretical predictions.

scholarly journals Reducing patients’ exposures to asthma and allergy triggers in their homes: an evaluation of effectiveness of grades of forced air ventilation filters

2014 ◽  
Vol 51 (6) ◽  
pp. 585-594 ◽  
Author(s):  
Kathleen Ward Brown ◽  
Taeko Minegishi ◽  
Joseph G. Allen ◽  
John F. McCarthy ◽  
John D. Spengler ◽  
...  
Keyword(s):  
Air Ventilation ◽  
Asthma And Allergy ◽  
Forced Air

Influence of ambient forced-air ventilation rate on potato storage wastage

1990 ◽  
Vol 33 (4) ◽  
pp. 433-440 ◽  
Author(s):  
P. Bertolini ◽  
A. Guarnieri
Keyword(s):  
Ventilation Rate ◽  
Potato Storage ◽  
Air Ventilation ◽  
Forced Air

DEVELOPMENT OF ADAPTIVE VENTILATION IN MULTIFUNCTIONAL LARGE-SCALE SPACE OF PUBLIC BUILDINGS

2021 ◽  
pp. 19-29
Author(s):  
Виталий Владимирович Шичкин ◽  
Мария Николаевна Жерлыкина ◽  
Сергей Анатольевич Яременко ◽  
Сергей Анатольевич Соловьев
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Large Scale ◽  
Numerical Study ◽  
Ventilation System ◽  
Public Buildings ◽  
Air Conditioners ◽  
Advantages And Disadvantages ◽  
Air Ventilation ◽  
Forced Air

Проанализирована актуальность строительства объектов культурно-массового назначения. Описана целесообразность проектирования многофункциональных трансформируемых помещений для общественных зданий. Приведены достоинства и недостатки применения рециркуляции воздуха как способа энергосбережения. Акцентировано внимание на поддержании чистоты воздуха в помещении и способах борьбы с бактериями и вирусами в приточном воздухе. Предложена схема многозональной общеобменной вентиляции воздуха без рециркуляции с блокированием кондиционеров для взаимозаменяемости с целью обеспечения микроклимата в многофункциональных помещениях общественных зданий. Описана последовательность работы системы вентиляции в теплый и холодный период года. Разработана система рекуперации с промежуточным холодоносителем для теплого периода года. Приведено описание работы установки кондиционирования воздуха. На примере реально существующего объекта выполнено численное исследование режимов работы системы вентиляции с рекуперацией теплоты и холода для трансформируемого помещения. Построен график для определения граничных условий работы рекуператора исходя из соотношения между интенсивностью теплообмена за счёт конвекции и интенсивностью теплообмена за счёт теплопроводности. При различных наружных температурах воздуха и расчетных температурах уходящего воздуха построены графики определения оптимальных параметров температуры воздуха на входе в утилизатор при оптимальных значениях водяного эквивалента . Выявлены и описаны режимы работы кондиционеров с теплоутилизатором в теплый период года, работающих в составе многозональной общеобменной вентиляции воздуха с блокированием кондиционеров для взаимозаменяемости. В ходе численного исследования выявлено, что наибольшая энергоэффективность системы вентиляции с рекуператором будет достигнута при принятии в качестве оптимального значения водяного эквивалента W = 3. We analyzed the relevance of cultural facilities construction. As well, we described the expediency of designing multifunctional transformable spaces for public buildings. Moreover we presented advantages and disadvantages of using air recirculation as a method of energy saving. A special attention is focused on maintaining indoor air clean and on various ways of combatting bacteria and viruses in the intake air. We offered a scheme of multi-zone forced air ventilation without recirculation with blocking air conditioners for interchangeability in order to provide a microclimate in multifunctional spaces of public buildings. We described the sequence of operations in the ventilation system in warm and cold seasons. We also developed a recuperation system with an intermediate refrigerant for warm seasons. The article presents a detailed description of the air conditioning unit operation. We carried out a numerical study of the operating modes of the ventilation system with heat and cold recovery for transformable spaces on the example of a real-existing facility. We show a graph to determine the boundary conditions of the recuperator operation based on the ratio between the intensity of heat transfer due to convection and the intensity of heat transfer due to thermal conductivity. At various outside air temperatures and design temperatures of the outgoing air, we created some graphs for determining the optimal parameters of the air temperature at the inlet to the heat exchanger at the optimal values of the water equivalent. We identified and described several modes of operation of air conditioners with a heat exchanger in warm seasons, operating as part of a multi-zone forced air ventilation with blocking air conditioners for interchangeability. In the course of a numerical study, it was revealed that the highest energy efficiency of a ventilation system with a recuperator could be achieved when the water equivalent value W = 3 is taken as the optimal value.

scholarly journals Efeito da secagem nas propriedades físicas dos grãos de feijão adzuki

2016 ◽  
Vol 37 (6) ◽  
pp. 3871
Author(s):  
Udenys Cabral Mendes ◽  
Osvaldo Resende ◽  
Juliana Rodrigues Donadon ◽  
Dieimisson Paulo Almeida ◽  
Anísio Correa da Rocha ◽  
...  
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Surface Area ◽  
Volume Ratio ◽  
Adzuki Bean ◽  
Projected Area ◽  
Air Ventilation ◽  
Length Width ◽  
Forced Air ◽  
Drying Conditions

The goal of the present study was to assess the effect of drying on the physical properties of adzuki bean (Vigna angularis Willd.). Adzuki beans with moisture content of 47.9% were dried in a oven with forced air ventilation at temperatures of 40, 60 and 80 °C and relative humidity of 18.5, 8.6, and 3.8%, respectively, until the moisture content reached 12.9%. We used 15 adzuki beans individualised in aluminium capsules. The orthogonal axes of the beans (length, width, and thickness) were measured at intervals of five percentage points during the reduction of moisture content. The parameters determined were: sphericity; circularity; volume of beans; volumetric contraction index; volume contraction percentage; surface area; projected area; and surface-volume ratio. The drying conditions altered the physical properties of adzuki bean. As a result of moisture content reduction, there was increased sphericity and surface-volume ratio, and decreased volume, unitary volumetric contraction, surface area, and projected area. Circularity was not influenced by the drying temperatures within the range of moisture content analysed.

scholarly journals Physical quality of grains subjected to moistening and drying processes for marketing

2016 ◽  
Vol 20 (9) ◽  
pp. 847-855
Author(s):  
Paulo C. Coradi ◽  
Alisson H. S. de Sousa ◽  
Lucas J. Camilo ◽  
Roney E. Lima ◽  
Lélia V. Milane ◽  
...  
Keyword(s):  
Water Movement ◽  
Transgenic Corn ◽  
Negative Effects ◽  
Physical Quality ◽  
Convection Oven ◽  
Grain Drying ◽  
Air Ventilation ◽  
Forced Air ◽  
Corn Grains

ABSTRACT The aim was to evaluate the physical quality of conventional and transgenic corn grains, through drying and wetting processes for marketing. The experimental design was completely randomized in a factorial scheme (7 x 3 x 2), corresponding to seven drying times (0, 20, 40, 60, 80, 100 and 120 min), three temperatures of the drying air (80, 100 and 120 °C) and two hybrids of corn (conventional AG 1051 and transgenic Herculex@ 30S31H). Grain drying was held in convection oven with forced air ventilation while the wetting was done in a B.O.D chamber. The water movement in the grain, the volume and the electrical conductivity were evaluated periodically. The results showed that the transgenic corn grain reduced the negative effects of drying and moistening on the physical quality. The increase in drying air temperature accelerated the physical deterioration of conventional and transgenic corn grains. The increase in water content by the moistening process caused losses in grain physical quality, similar to the drying process, for both the conventional and transgenic corn grains.

scholarly journals NUMERICAL RESEARCH OF THE MOISTURE CONDENSATION ELIMINATION IN THE CABIN OF THE UNIFIED TECHNOLOGICAL ELECTRIC TRANSPORT VEHICLE

2018 ◽  
Vol 15 (4) ◽  
pp. 538-546
Author(s):  
N. M. Filkin ◽  
A. M. Tatarkin
Keyword(s):  
Three Dimensional ◽  
Electric Transport ◽  
Three Dimensional Model ◽  
Ansys Fluent ◽  
Air Ventilation ◽  
Fluent Software ◽  
Moisture Condensation ◽  
Transport Vehicle ◽  
Numerical Research ◽  
Forced Air

Introduction. This article deals with the problem of moisture condensation inside the cabin of the technological electric transport vehicle. The hypothesis of using the forced air ventilation in the cabin is substantiated, by which such problem could be solved.Materials and methods. The article describes the application of the ANSYS Fluent Software Package to assess the effect of the location and shape of the ducts on the ventilation process inside the cabin. Accordingly, the key stages of air flow modeling in this program are considered.Results. The main content of the research is to analyze the modeling airflow process in the cabins with a different configuration of inlet and outlet nozzles. Therefore, basing on the analysis of the obtained airflow velocity contours, the conclusion is made about the rational arrangement of the inlet and outlet channels.Discussion and conclusions. The conclusion is made about the necessity of the further research that would refer to creating a three-dimensional model of the cabin. The results of the research as well as resolutions are taken into account.

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