scholarly journals Thermal regeneration of waste foundry phenolic sand in a lab scale fluidized bed

2018 ◽  
Vol 23 (1) ◽  
Author(s):  
Johny Anderson Severo ◽  
Regina Célia Espinosa Modolo ◽  
Carlos Alberto Mendes Moraes ◽  
Flávia Schwarz Franceschini Zinani
Keyword(s):  
Fluidized Bed ◽  
Regeneration Process ◽  
Process Conditions ◽  
Loss On Ignition ◽  
Molding Process ◽  
Partial Removal ◽  
Thermal Regeneration ◽  
Previously Treated ◽  
Regeneration Efficiency

ABSTRACT Improper disposal of sand used in molding processes after casting increases logistical costs and environmental impact because of the presence of the phenolic resin in its composition. The regeneration process of waste foundry phenolic sand (WFPS) aims to recycle this material. As mechanical regeneration methods are not efficient to guarantee 100% cleaning of the sand grains and their use again in the molding process, this work investigated the efficiency of a method of thermal regeneration of this type of residue that can be employed as a complementary procedure. A laboratory-scale fluidized bed reactor was designed and built to regenerate WFPS that was previously treated by a mechanical method. The methodology used to design and construct the fluidized bed prototype is described, as well as the characterization of the residual, the standard clean sand and the regenerated sand. The results of the thermal regeneration in the fluidized bed were very satisfactory with respect to the regeneration efficiency. For the nine process conditions tested, loss on ignition values were reduced when compared to standard clean sand. This study presents the advantages of a combination of two processes, mechanical and thermal regeneration, which allows to reduce the time and eventual temperature of resin removal due to the partial removal of the resin layer or its weakening during the mechanical regeneration process. Of the nine process conditions tested, six had loss on ignition values below the CSS. Thus, the thermal regeneration in the fluidized bed results was quite satisfactory in relation to the regeneration efficiency.

Characterization of effective permeability of prepreg fibers under autoclave molding process conditions using process model simulations

2020 ◽  
Vol 112 (1) ◽  
pp. 1-7
Author(s):  
Prosenjit Maji ◽  
Arpit Jain ◽  
Nibedita Dutta ◽  
Ahmed Ovais Siddiqui ◽  
Debdarsan Niyogi ◽  
...  
Keyword(s):  
Process Model ◽  
Effective Permeability ◽  
Process Conditions ◽  
Molding Process ◽  
Model Simulations

Thermal Regeneration of Mineral Sorbent Using Burner Unit

2013 ◽  
Vol 34 (2) ◽  
pp. 191-201 ◽  
Author(s):  
Robert Sekret ◽  
Jan Koldej
Keyword(s):  
Diesel Oil ◽  
Fire Service ◽  
Regeneration Process ◽  
Process Conditions ◽  
Second Phase ◽  
Thermal Regeneration ◽  
Average Value ◽  
Start Up ◽  
Physico Chemical ◽  
Mineral Sorbent

This article presents the results of scientific investigations on the thermal regeneration process of a sorbent of mineral origin sorbent using a retort burner. Diesel oil, a petroleum liquid, most often pervades the environment during different catastrophes. The investigated sorbent of mineral origin was used in the standard way that the Fire Service removes such petroleum liquids from the environment during disasters. For research purposes, a regeneration chamber with a retort burner was constructed. The first phase of the investigation was aimed at defining the physico-chemical features of the sorbent after subsequent cycles of the regeneration process. The second phase involved an analysis of the energy and ecological effects of the regeneration process. The results showed that the first three cycles of the regeneration process occurred under low emission conditions. The proposed regeneration method achieved a positive energetic effect with a functional heat stream with an average value of 12.4 kW (average efficiency of the regeneration chamber was 68 %). The method is very efficient, with regeneration rates between 7.2 kg/h and 8.4 kg/h. It requires only a short amount of time for the start-up and extinction of the regeneration chamber, and it is also flexible to changes in the process conditions.

Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

1989 ◽  
Vol 21 (4-5) ◽  
pp. 157-165 ◽  
Author(s):  
F. Ehlinger ◽  
J. M. Audic ◽  
G. M. Faup
Keyword(s):  
Fluidized Bed ◽  
Future Development ◽  
Protein Concentration ◽  
Specific Activity ◽  
Fluidized Bed Reactor ◽  
Fluidized Bed Reactors ◽  
Support Material ◽  
Biofilm Development ◽  
Initial Biofilm

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

3D Micromixer

2012 ◽  
Author(s):  
Bahador Farshchian ◽  
Junseo Choi ◽  
Sunggook Park
Keyword(s):  
Cover Plate ◽  
Bottom Surface ◽  
Mixing Efficiency ◽  
Molding Process ◽  
Specific Flow ◽  
Pdms Stamp ◽  
Fluorescein Dye ◽  
Solvent Bonding ◽  
Peeling Off

This paper presents the fabrication of a 3D microchannel whose sidewalls and bottom surface are patterned with ratchets using a modified 3D molding process. In the modified 3D molding process the surface of poly(methyl methacrylate) (PMMA) is first patterned using a brass mold having ratchet structures. Then PDMS prepolymer was spin coated over the surface of micropatterned PMMA and cured followed by the primary molding using a brass mold having a T-conjunction protrusion. After primary molding demolding was done by first demolding the brass mold and then peeling off PDMS stamp from PMMA substrate. By setting a 45° angle between direction of ratchets patterned on the surface of PMMA and the brass mold protrusion prior to primary molding 45° slanted ratchets were formed on the sidewall and bottom surface of microchannel using the modified 3D molding. The scanning electron microscope (SEM) micrographs show a successful integration of micropatterns inside the microchannel. Holes were drilled in the inlet and outlet area of the 3D channel before bonding. A solvent bonding technique was used for bonding of 3D channel to a plain cover plate. After bonding capillary tubes were inserted into the holes and glued to the chip using an epoxy glue. For characterization of mixing fluorescence intensity was quantified in the 3D microchannel as deionized water and fluorescein dye injected from different inlets of 3D micromixer were mixed along the 3D microchannel and mixing efficiency was calculated. The results were compared with the data obtained for similar microdevice whose surfaces were not patterned. The results demonstrate at a specific flow rate a faster mixing occurs in a microdevice whose sidewall and bottom surface are patterned with slanted 45° ratchets.

scholarly journals Research on Local Heating Regeneration Method for Air-Conditioning Systems

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 444
Author(s):  
Feng Cheng ◽  
Yunlei Wu ◽  
Xiuwei Li
Keyword(s):  
Air Conditioning ◽  
Local Heating ◽  
Solution Concentration ◽  
Regeneration Process ◽  
Future Application ◽  
Liquid Volume ◽  
Thermal Regeneration ◽  
Lower Efficiency ◽  
Good Potential ◽  
Air Conditioning Systems

Absorption air-conditioning systems have a great advantage in terms of energy conservation and environmental protection. However, the large amount of energy waste in the thermal regeneration process leads to lower efficiency and impedes its development. To reduce energy loss and improve performance, a local heating regeneration method is proposed in this paper. The main principle is reducing the volume of the liquid participating regeneration. Including the solar steam mode, two modes are introduced and configured. Theoretical and experimental research has been made on the new methods. Models have been developed for comparison analysis. Experiments have been conducted on water and absorbent solution with different modes. Performance has been evaluated based on the experimental data. The results expose the influence of different parameters, like liquid volume and solution concentration, on the regeneration process. The local heating method improved the regeneration efficiency by 40% in the no solar steam mode and the performance tripled in the solar steam mode. The COP (the ratio of cooling load to energy consumption) of the absorption system with the solar steam mode is more than two times of that with the traditional regeneration mode. It shows the local heating regeneration method has good potential in future application.

Physico-Chemical Characterization of Alumina Sols Prepared From Aluminum Alcoxides

1986 ◽  
Vol 73 ◽  
Author(s):  
William L. Olson
Keyword(s):  
Room Temperature ◽  
Gel Filtration ◽  
Chemical Characterization ◽  
Process Conditions ◽  
Chemical Processing ◽  
Rotary Evaporation ◽  
Physico Chemical ◽  
Elution Curves ◽  
Alumina Sol

ABSTRACTAlumina sols derived from aluminum sec-butoxide (Yoldas) were characterized. The distribution of the polymer sizes within the sol, determined by gel filtration chromatography (GFC), was found to be dramatically affected by small changes in the chemical processing or preparative procedure. Aging the sol at room temperature for two weeks produced no significant change in the GFC elution curves of the alumina sol. Sols with a “milky” appearance were found to exhibit a wider distribution of polymers by GFC than transparent sols. Rotary evaporation of the sol followed by redissolution of the residue was found to change the polymer size distribution described by the gel filtration elution curves. These observations coupled with 27Al NMR spectroscopy and viscometry measurements were used to elucidate the effects of process conditions and aging on the molecular structure of the sol.

Sign in / Sign up

Export Citation Format

Share Document