The Modular Design Concept of Decentralized Sewage Reuse Equipment and its Application

2014 ◽  
Vol 955-959 ◽  
pp. 3323-3330
Author(s):  
Zhi Wei Xiao ◽  
Jia He ◽  
Nan Qi ◽  
Jia Peng Wen ◽  
Xiu Bo Chen ◽  
...  
Keyword(s):  
Membrane Filtration ◽  
Modular Design ◽  
Biofilm Reactor ◽  
Design Concept ◽  
Operation Condition ◽  
Engineering Project ◽  
Operation Conditions ◽  
Membrane Processing ◽  
Processing Module ◽  
Sewage Reuse

With biofilm reactor and continuous membrane filtration as the core, this paper proposes to establish biochemical module and membrane processing module, which can from the biofilm - membrane filtration process. In the part of biochemical module, diverse processing function can be realized by adjusting the operation conditions of the pumps and fans. Meanwhile, the number and operation condition of biochemical module could be changed flexibly according to the actual processing needs. Thereby, the standardization and generalization of biochemical module can be achieved. And in the part of membrane processing module, the processing capacity can also be expanded through frequency converting control and increasing the number of membrane module. An engineering project of decentralized sewage reuse is built, and the outlet water quality can reach the expected standard, which suggests that the modular design concept has good feasibility.

Design of a Counterweight Walker Active Therapeutic Movement Rehabilitation Rig

2013 ◽  
Author(s):  
Israel Aguilera Navarrete ◽  
Alejandro A. Lozano Guzmán
Keyword(s):  
Modular Design ◽  
Design Concept ◽  
Walking Ability ◽  
Mechanical Device ◽  
Dynamic Calculation ◽  
Client Needs ◽  
Walking Aid

According to INEGI (National Institute for Statistics and Geography), in 2004 there were around 730,000 people in Mexico with the need of some kind of mechanical aid to regain ability to walk. Support equipment for regaining the ability to walk normally is manufactured outside of Mexico. This equipment is complex and very expensive. In this work, the design of a walking ability rehabilitation aid is presented. This work is carried out applying the modular design concept. This ensures that all client needs are fulfilled by the resultant product, and that these needs are measurable and controllable. Basic idea behind this design is supporting part of patient’s weight and that of an exoskeleton on a mechanical device. Basic kinematics and dynamic calculation are presented, as well as simulations results. This information shows the feasibility of building and operating this rehabilitation walking aid.

Comparative study on membrane fouling between membrane-coupled moving bed biofilm reactor and conventional membrane bioreactor for municipal wastewater treatment

2013 ◽  
Vol 69 (5) ◽  
pp. 1021-1027 ◽  
Author(s):  
W. Yang ◽  
W. Syed ◽  
H. Zhou
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Biofilm Reactor ◽  
Municipal Wastewater Treatment ◽  
Moving Bed Biofilm Reactor ◽  
Reactor Unit ◽  
Polyaluminum Chloride ◽  
Moving Bed

This study compared the performance between membrane-coupled moving bed biofilm reactor (M-MBBR) and a conventional membrane bioreactor (MBR) in parallel. Extensive tests were conducted in three pilot-scale experimental units over 6 months. Emphasis was placed on the factors that would affect the performance of membrane filtration. The results showed that the concentrations of soluble microbial product (SMP), colloidal total organic carbon and transparent exopolymer particles in the M-MBBR systems were not significantly different from those in the control MBR system. However, the fouling rates were much higher in the M-MBBR systems as compared to the conventional MBR systems. This indicates membrane fouling potential was related not only to the concentration of SMP, but also to their sources and characteristics. The addition of polyaluminum chloride could reduce the fouling rate of the moving bed biofilm reactor unit by 56.4–84.5% at various membrane fluxes.

Investigation of the spark ignition enhancement in a supersonic flow

2014 ◽  
Vol 28 (29) ◽  
pp. 1450226 ◽  
Author(s):  
Zun Cai ◽  
Zhen-Guo Wang ◽  
Ming-Bo Sun ◽  
Hong-Bo Wang ◽  
Jian-Han Liang
Keyword(s):  
Ignition Time ◽  
Spark Ignition ◽  
Dominant Factor ◽  
Ignition Process ◽  
Operation Condition ◽  
Flame Kernel ◽  
Operation Conditions ◽  
Key Factor ◽  
Lean Fuel ◽  
Spark Energy

Ethylene spark ignition experiments were conducted based on an variable energy igniter at the inflow conditions of Ma = 2.1 with stagnation state T0 = 846 K , P0 = 0.7 MPa . By comparing the spark energy and spark frequency of four typical operation conditions of the igniter, it is indicated that the spark energy determines the scale of the spark and the spark existing time. The spark frequency plays a role of sustaining flame and promoting the formation and propagation of the flame kernel, and it is also the dominant factor determining the ignition time compared with the spark energy. The spark power, which is the product of the spark energy and spark frequency, is the key factor affecting the ignition process. For a fixed spark power, the igniter operation condition of high spark frequency with low spark energy always exhibits a better ignition ability. As approaching the lean fuel limit, only the igniter operation condition (87 Hz and 3.0 J) could achieve a successful ignition, where the other typical operation conditions (26 Hz and 10.5 J, 247 Hz and 0.8 J, 150 Hz and 1.4 J) failed.

scholarly journals Parametric evaluation of the technical object suitability based on analyze the quality of its maintenance and use taking into account the initial conditions

2018 ◽  
Vol 182 ◽  
pp. 01006
Author(s):  
Rafał Grądzki
Keyword(s):  
Equations Of State ◽  
Initial Conditions ◽  
Technical Condition ◽  
Operation Condition ◽  
Technical Object ◽  
Coupled Equations ◽  
Reliability Parameters ◽  
Operation Conditions ◽  
Operational Data

In this paper, the comparison of three various technical objects (engines of public transport buses) exploitation research for different initial conditions are presented. Object researches were carried out in 2012 and then repeated in 2013. Gathered operational data is presented in three sets (1 – concerning object, 2 – concerning driving conditions, 3 – concerning driver, where set 1 is the collection of diagnostic information Dk, and sets 2 and 3 are the information about object environment U) in form of conventional points (experts numerical assessments). Relation between point information of object and point information of environment was described by coupled equations of state (describing relations between operation condition and technical condition including initial conditions for each analyzed exploitation period). That method allows to determine parameters of technical condition aT and operation condition aR and next, from the course of aT parameter, set of parametrical damage mT(t) and from course of parameter aR – set of momentary damage aR(t). Thus it is possible to evaluate exploitation, technical and operation conditions of each object (bus engine). Received reliability parameters allows to properly control exploitation and service of particular objects and set of objects (fleet of buses) and its elements.

Study on Aerodynamic Redesign of a High Pressure Ratio Centrifugal Compressor

2010 ◽  
Author(s):  
Chaolei Zhang ◽  
Qinghua Deng ◽  
Zhenping Feng
Keyword(s):  
Centrifugal Compressor ◽  
Cfd Simulation ◽  
Pressure Ratio ◽  
Aerodynamic Performance ◽  
Compressor Stage ◽  
Operation Condition ◽  
Vaned Diffuser ◽  
Centrifugal Compressor Stage ◽  
Optimum Configuration ◽  
Operation Conditions

This paper describes the aerodynamic redesign and optimization of a typical single stage centrifugal compressor, in which the total pressure ratio was improved from the original 4.0 to final 5.0 with the restrictions of keeping the impeller tip diameter, the design rotational speed and the design mass flow rate unchanged. Firstly the backsweep angle and the outlet blade height of the impeller were adjusted and the vaned diffuser was redesigned. Then a sensitivity analysis of the aerodynamic performance correlated to the primary redesign centrifugal compressor stage with respect to the chosen redesign variables was conducted, according to the parameterized results of the impeller and the vaned diffuser. Secondly the impeller and the vaned diffuser were optimized respectively under the stage environment at the design operation condition to improve the stage isentropic efficiency by using a global optimization method which coupled Evolutionary Algorithm (EA) and Artificial Neural Network (ANN), provided by the commercial software NUMECA DESIGN-3D. Subsequently the detailed performance maps of the centrifugal compressor stage corresponding to the primary redesign configuration and the optimum configuration were presented by Computational Fluid Dynamics (CFD) simulation. Finally the flow fields correlated to the centrifugal compressor configurations before and after optimization at the design operation condition were also compared and analyzed in detail. As a result the design target was achieved after the primary redesign, as a 2.7% gain in stage efficiency and a 3.6% increase in stage pressure ratio were obtained when compared with the primary redesign configuration after optimization. Moreover, the aerodynamic performance of the optimum configuration at the off-design operation conditions was also improved.

Aerodynamic Design Optimization of the Last Stage of a Multi-Stage Compressor by Using an Adjoint Method

2016 ◽  
Author(s):  
Jing Yang ◽  
Jiaqi Luo ◽  
Juntao Xiong ◽  
Feng Liu
Keyword(s):  
Design Optimization ◽  
Adjoint Method ◽  
Guide Vane ◽  
Inlet Guide Vane ◽  
Optimization Approach ◽  
Operation Condition ◽  
Operation Conditions ◽  
Multi Stage ◽  
Last Stage ◽  
Continuous Adjoint

The paper presents the aerodynamic optimization of the last row of a 4.5-stage compressor by means of a gradient-based optimization method that utilizes the continuous adjoint approach. An adjoint mixing-plane formulation is used to allow for the computation of adjoint solutions for multistage turbomachinery problems. Firstly, a conventional one-dimensional design method and empirical correlations are used to produce a base design of a 4.5-stage low-speed, low compression ratio compressor with an inlet guide vane to adjust to different operation conditions. Then the last stage is redesigned by the adjoint method to reduce the flow losses at the operation condition near stall through modifying the aerodynamic shape and stagger angle of the stator blade. The cost function is defined as a weighted sum of the entropy production and a constraint on the mass flow rate. Finally, a multi-point design optimization approach by using the adjoint method is employed to improve the performance of the last stage at two different operation conditions. The results demonstrate that the stator shape modifications improve the aerodynamic performance of the stage and illustrate the functionality of the adjoint-based multi-stage optimization system.

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