Proposal for Cryogenic Deburring Equipment’s Design and Thermal Insulation

In the paper are presented elements of the deburring technology of rubber or plastic parts in cryogenic conditions. There is a proposal for deburring equipment that follows: simplicity in use, increased production capacity and reduced consumption of liquid nitrogen. The heat transfer through the insulating layer is calculated using several types of thermal insulation: perlite powder, spray-on polyurethane foam and aerogel blanket. The obtained results are used for the design of a cryogenic deburring equipment where the thermal transfer is minimal.

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PROCESSED STRAW AS EFFECTIVE THERMAL INSULATION FOR BUILDING ENVELOPE CONSTRUCTIONS

Engineering Structures and Technologies ◽

10.3846/2029882x.2012.730286 ◽

2012 ◽

Vol 4 (3) ◽

pp. 96-103 ◽

Cited By ~ 4

Author(s):

Jolanta Vėjelienė

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Thermal Insulation ◽

Building Envelope ◽

Gas Content ◽

Barley Straw ◽

Conductivity Measurements ◽

Insulation Materials ◽

Thermal Transfer ◽

The Impact

The efficiency of thermal insulation materials obtained from renewable resources depends on the possibilities of reducing thermal transfer via solid and gaseous conduction, thermal radiation and, in some cases, convection. The heat transfer mechanism for thermal insulation materials mostly depends on the structure and density of the material used. Efficient thermal insulation materials consist of a gaseous phase and a solid skeleton. Gas content in such materials can take more than 99% of material by volume. In this case, thermal transfer via solid conductivity is negligible. The current work analyses the possibilities of reducing heat transfer in the straw of a varying structure. For conducting experiments, barley straw was used. To evaluate the impact of straw stalk orientation in a specimen on thermal conductivity, strongly horizontally and vertically oriented specimens of straw stalks were prepared. To reduce heat transfer via gaseous conduction and convection in large cavities in straw stalks and between stalks, barley straw were chopped and defibered. In order to decrease heat transfer via radiation after thermal conductivity measurements, mechanically processed straw were coated with infrared absorbers. Due to thermal conductivity measurements of chopped and defibered straw, an optimal amount of infrared absorbers were determined.

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Reduction of Heat Transfer to High Velocity Gun Barrels by Wear-Reducing Additives

Journal of Heat Transfer ◽

10.1115/1.3450880 ◽

1978 ◽

Vol 100 (4) ◽

pp. 697-701 ◽

Cited By ~ 3

Author(s):

J. R. Ward ◽

T. L. Brosseau

Keyword(s):

Heat Transfer ◽

Polyurethane Foam ◽

Fold Increase ◽

Axial Distance ◽

Single Shot ◽

Insulating Layer ◽

Gun Barrel ◽

Wear Life ◽

Design Optimum ◽

Made In

In order to understand how wear-reducing additives such as TiO2/wax and polyurethane foam liners reduce erosion, a series of gun firings was made in a 105 mm tank cannon equipped with thermocouples to measure the heat transferred to the gun barrel both in the presence and in the absence of the additives. Four thin thermocouples (0.13 mm diameter) were placed at different radial distances from the bore surface. Each thermocouple was placed at the same axial distance along the gun barrel. From the temperature distribution measured 100 milliseconds after propellant ignition, the total heat transferred in the gun barrel was determined. On the basis of single shot measurements, both the polyurethane foam and the TiO2/wax liner reduced the heat transferred to the gun barrel by ten percent. Repeated firings with TiO2/wax liners afforded steadily increasing reduction in heat transfer which was attributed to the formation of an insulating layer of TiO2 and unreacted wax on the bore surface. This also accounts for the twenty-five fold increase in wear life of the M68 tank cannon firing rounds equipped with TiO2/wax liners. This thermocouple technique is now used to design optimum weight and location of wear-reducing additives in other gun systems, since the efficacy of the wear-reducing liner can be deduced from a few shots.

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Understanding the Dynamic and Static Thermal Transfer in Brick Walls

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.512-515.2834 ◽

2012 ◽

Vol 512-515 ◽

pp. 2834-2837 ◽

Cited By ~ 1

Author(s):

Emilio Sassine ◽

Zohir Younsi ◽

Yassine Chérif ◽

Emmanuel Antczak

Keyword(s):

Heat Transfer ◽

Steady State ◽

Thermal Insulation ◽

Brick Wall ◽

Equivalent Resistance ◽

Thermal Transfer ◽

Electrical Analogy ◽

State Case

The aim of this paper is to study the thermal heat transfer through a 33 cm brick wall, typical of old houses in Lille, a northern French town. First, the wall was studied in a steady state case in order to determine its equivalent resistance using the electrical analogy. Then, the wall is replaced by an equivalent homogeneous wall in order to compare the 1D and the 3D thermal transfer. The results show a perfect consistency between the two models, representing a big advantage when other layers are added to the model like thermal insulation and facing.

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Experimental Study on Thermal Insulation Properties of Reinforced Concrete Composite Wall

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.99-100.676 ◽

2011 ◽

Vol 99-100 ◽

pp. 676-679 ◽

Cited By ~ 2

Author(s):

Shun Bo Zhao ◽

Su Yang ◽

Li Sha Song ◽

Li Sun ◽

Chen Xiao Song

Keyword(s):

Heat Transfer ◽

Experimental Study ◽

Reinforced Concrete ◽

Thermal Insulation ◽

Bearing Surface ◽

Paper Briefly ◽

Insulating Layer ◽

Building Envelop ◽

Composite Wall ◽

Heat Bridge

The paper briefly introduces the form and construction method of a new reinforced concrete composite wall (RCCW) with inner insulating layer of polystyrene panel. The thermal insulation properties such as heat resistance, heat exchange resistance and heat transfer coefficient of the RCCW were measured by the protection chest method, six specimens in dimensions of 1450mm×1450mm×300mm were cast with the same thickness of prototype walls of building envelop, three kinds of linkages of the RCCW were considered, and two surfaces of the specimen were tested respectively as the heat bearing surface to simulated different heat resources. Based on the tests, the effects of linkages and heat resources on thermal insulation properties of the RCCW are analyzed, some improvements are proposed for reducing the heat-bridge effects as much as possible.

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Weathering of Roofing Insulation Materials under Multi-Field Coupling Conditions

Materials ◽

10.3390/ma12203348 ◽

2019 ◽

Vol 12 (20) ◽

pp. 3348 ◽

Cited By ~ 1

Author(s):

Shuangxi Zhou ◽

Yang Ding ◽

Zhongping Wang ◽

Jingliang Dong ◽

Anming She ◽

...

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Mass Loss ◽

Polyurethane Foam ◽

Thermal Insulation ◽

Rigid Polyurethane Foam ◽

Foam Concrete ◽

Insulation Materials ◽

Field Coupling ◽

Vacuum Insulation

Rigid polyurethane foam, foam concrete, and vacuum insulation board are common roofing insulation materials. Their weathering performance under long-term multi-field coupling determines the overall service life of the roof. The weathering properties of rigid polyurethane foam, foam concrete and vacuum insulation panels were studied under freeze thaw, humid-heat, dry-wet, high-low temperature, and multi-field coupling cycles, respectively. The heat transfer and construction process of roof panels was simulated base on upper loading and moisture transfer factors. The result indicates that the mass loss of the foam concrete and the rigid polyurethane foam in the weathering test was significant, which led to the gradual increase of thermal conductivity. Meanwhile, the thermal conductivity and mass loss of vacuum insulation panels did not change due to the lack of penetration under external pressure, therefore, it is necessary to construct composite thermal–insulation materials to alleviate the adverse effects of the service environment on a single material and realize the complementary advantages and disadvantages of the two materials. The results of the numerical simulations indicated that the roof structure must be waterproofed, and its weatherproof performance index should be the same as that of the thermal insulation material. Considering structural deformation, the overall heat transfer performance of the product was increased by around 5%.

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