Sealing Technology

Porous ceramic mechanical seal ring
Sealing Technology

Sliding member, mechanical seal ring and faucet valve Mechanical seal ring
Surface treatment process for ceramic mechanical seal rings

Mechanical seal ring

A thermoeconomic analysis of biomass energy for trigeneration 生物燃料/生物质能源工厂: 生产工艺及其设备

Design and control of drum dryers for the food industry. Part 2. Automatic control 食品干燥加工企业的鼓形干燥机及其输送传动设备 自动控制系统的设计和运行 Journal of Food Engineering
Changes in operating conditions and process disturbances produce unevenness in the final moisture content of a product dried on a drum dryer. Moisture unevenness exists as a function of both time and drum width. The aim of this work is to control the final moisture content of the product and to reduce its unevenness, in order to obtain a high quality product and to increase dryer productivity. Among all input process variables, two control variables were chosen: the drum speed (Vrc), and the heating steam pressure (pv). These variables were used to keep constant the average final moisture content Xf .

In this paper we present a case where classic control is not enough to correct some process perturbations. Therefore, the facility has been modified by adding an actuator, in this case an inductive electric heater. Local complementary heating power (Pind) is used to correct local heterogeneity of Xf to obtain Xf = Xf at every point across the drum.

Regression metamodeling for the design of automated manufacturing system composed of parallel machines sharing a material handling resource Production Economics

This study concerns a particular type of automated manufacturing system, composed of parallel machines sharing a material handling resource often encountered in practice. For the company, with which we work, these expensive systems are frequently the bottleneck of the global plant, so that designers are interested in continuously improving them. In this respect, the important factors and the consequences on the average system utilization, if certain factors change, are pointed out and quantified, through regression metamodeling of a stochastic simulation model. The metamodel developed provides the decision-makers and the designers with useful insight into these systems. For example, it highlights that the material handling resource speed and acceleration value were quite not as influent on the performance measure as expected by the experts.

Article Outline

1. Introduction 2. Type of industrial systems under study 3. Sensitivity analysis 4. Regression metamodeling 4.1. Experimental design used 4.2. Regression analysis 4.3. Interpretation of the metamodel 5. Conclusion References

Towards an integrated model of operation allocation and material handling selection in cellular manufacturing systems 物料处理工厂/工作单元的物料挑选/筛选/输送/装载集成化操作设备 目标优化与效能提高
An integrated approach to operation allocation (OA) and material handling systems selection (MHSS) in cellular manufacturing systems is presented. The OA model assigns the operations of a set of part types to a group of machines, and provides this information as input to the MHSS model. The MHSS model allocates equipment for handling the parts between machines as well as at a machine. This information is

then fed back as an input to the OA model. An iterative algorithm is developed to solve the two models sequentially, and a numerical example is provided to demonstrate the applicability of the models.

Article Outline

1. Introduction 2. Literature review 3. The mathematical models 3.1. Sub-model 1: Operation allocation 3.2. Sub-model 2: Material handling system selection 3.3. Justification: Cost of transportation MH operation 3.4. Algorithm to solve the two models iteratively 4. A numerical example 4.1. The operation allocation problem 4.2. The MH system selection problem 4.3. Solution to the numerical example 5. Analysis and conclusions

Design of material flow networks in manufacturing facilities 制造设施中的物料流程设计 Journal of Manufacturing Systems
In this paper we consider the design of material handling flow paths in a discrete parts manufacturing facility. A fixed-charge capacitated network design model is formulated, and two efficient heuristics are proposed to determine near-optimal solutions to the resulting NP-hard problem. The first heuristic iteratively adjusts the arc fixed costs and selectively includes arcs in the flow network until a feasible network is obtained. The second heuristic partially explores the problem state-space. Both heuristics are tested against an implicit enumeration scheme used to obtain optimal solutions for small examples. For more realistic cases, solutions are compared to lower bounds obtained by linear programming relaxation of the mixed integer program or by an iterative dual-ascent algorithm. Results indicate that, on average, the heuristics provide good solutions in reasonable time. The proposed methodology is applied to design flow paths of an existing manufacturing facility. The role of the flow path network problem in integrated shop design is also discussed.

Advanced material handling system for computer integrated manufacturing

Robotics and Computer-Integrated Manufacturing

机器人物料处理系统 计算机平台
A cordless linear synchronous motor (LSM) material handling system for CIM has been developed. The system incorporates a courier that moves without tether restrictions. This provides for an automated material handling system with improved travel and flexibility. The material handling system runs on an integrated reverse air bearing system which eliminates friction and backlash. The proposed system forms part of a manufacturing assembly, interacting with overhead manipulators and part feeders to form a comprehensive production system. The design and implementation of the cordless linear motor material handling system (MHS) is outlined and described in the paper.

Article Outline

1. Introduction 2. Cordless LSM design and operation 3. Reverse air bearing 4. Control system 5. Manufacturing assembly 6. Future work 7. Conclusion References

Buffer levels and choice of material handling device in flexible manufacturing systems European Journal of Operational Research
The determination of buffer sizes is a key issue in the design of a Flexible Manufacturing System (FMS). A study of FMS installations and the systems indicates the relationship between the buffer capacity and the type of primary and secondary Material Handling Systems (MHSs) employed. A priori knowledge about the buffer requirements enables the FMS designer to select appropriate MHS devices. This paper addresses the issue of determining buffer capacities through simulation. Using response surface methodology for efficient experimentation, the best combination of central and local buffer is obtained.

An integrated model and a decomposition-based approach for concurrent layout

and material handling system design Computers & Industrial Engineering
This paper presents an integer programming formulation that integrates decisions concerning the layout of the resource groups on the shop floor with the design of the material handling system. The model reflects critical practical concerns, including the capacity of the material flow network and of the handling transporters, as well as the tradeoff between fixed (construction and acquisition) and variable (operational) costs. For realistic industrial cases, the size of the problem prevents the solution using explicit or implicit enumeration methods. Instead, the global model is decomposed into standard optimization problems: quadratic assignment, fixed charge capacitated network design, and non-depot distance-constrained vehicle routing. An integrated solution method, guided by a simulated annealing scheme, solves the global shop design problem. The algorithm takes advantage of the proposed decomposition and converges to a final design which is feasible with respect to all problem constraints. The method is applied to redesign the facility of a large manufacturer of radar antennas. The resulting shop configuration exhibits substantially decreased material handling effort, and requires significantly smaller investment costs compared to the existing facility.

Article Outline

1. Introduction 2. The need for integrated shop design 3. The shop design model 3.1. Representation of geometrical attributes 3.2. Assumptions and notation 3.3. Definition of decision variables 3.4. Mathematical formulation 4. Model decomposition 4.1. Material flow network design 4.1.1. Step 1: fixing variables 4.1.2. Step 2: eliminating constraints 4.1.3. Step 3: aggregating constraints 4.1.4. Step 4: mixed-integer programming model

4.2. Transporter routing 4.2.1. Step 1: fixing variables 4.2.2. Step 2: eliminating/transforming constraints 4.2.3. Step 3: reducing the objective function 4.2.4. Step 4: integer programming model 4.3. Quadratic assignment 4.3.1. Step 1: fixing variables 4.3.2. Step 2: eliminating constraints 4.3.3. Step 3: binary program 5. An integrated design approach 5.1. Shop layout using simulated annealing 5.2. Integrated material handling system design 5.2.1. Stage 1: initialization 5.2.2. Stage 2: determination of unloaded moves, routes, and route sets 5.2.3. Stage 3: design of the material flow network 5.2.4. Stage 4: evaluation of the transporter fleet size 5.2.5. Stage 5: adjustment of arc capacities or termination 6. Industrial application 6.1. Design inputs 6.2. Resulting shop design 6.3. Discussion


Real-time holonic scheduling of material handling operations in a dynamic manufacturing environment 物流设备的时序性和灵捷化设计 物料处理操作系统

In a real-world manufacturing environment, finding the right sequences and associated schedules with resource, precedence, and timing constraints is a difficult task. Moreover, a decision time period of hours or even minutes is simply too long. Good solutions are often needed in real time. One approach to overcome the limitations of classical scheduling is the use of distributed schemes such as agent or

holonic-based control architectures. This paper presents a solution for scheduling material handling devices in the cellular manufacturing environment using the holonic control approach. In holonic systems, under real-time constraints, a feasible schedule for the material handling devices emerges from the combination of individual material handling holons’ schedules. Internal evaluation and allocation algorithms and specific cooperation mechanisms between the holons in the architecture are the basis for the resultant emergent schedules. These evaluation algorithms are developed using several scenarios that take into account uncertainties that usually exist in a dynamic manufacturing environment, such as new orders entering into the system. The study results obtained show that the holonic system is capable of accommodating new arriving jobs and delivers good solutions in real time.

Article Outline

1. Introduction 2. Influence of material handling in manufacturing scheduling 3. Scheduling in holonic systems 4. Job evaluation and allocation algorithms 4.1. Order and material handling holons job evaluation and allocation procedure 4.2. The individual schedules generation mechanism 4.3. The system level schedule generation algorithm 4.4. Inter-material handling holon cooperation algorithm 5. Preliminary tests and results 5.1. Lower bound on makespan 5.2. Assignment of jobs to the material handling devices 5.3. Generation of the system level schedule 5.4. Inter-MHH cooperation improvements to the initial system level schedule 5.5. Comparison of the initial SLS with all possible MH devices schedules 5.6. Influence of material handling operations 6. Conclusions and future work Acknowledgements References

Exact and heuristic procedures for the material handling circular flow path design problem
In this study we develop optimization, decomposition, and heuristic procedures to design a unidirectional loop flow pattern along with the pickup and delivery station locations for unit load automated material handling vehicles. The layout of the facility is fixed, the edges on the boundary of the manufacturing cells are candidates to form the unidirectional loop flow path, and a set of nodes located at an intermediate point on each edge are candidates for pickup and delivery stations of the cell formed by those edges. The objective is to minimize the total loaded and empty vehicle trip distances. The empty vehicle dispatching policy underlying the model is the shortest trip distance first. A binary integer programming model describes the problem of determining the flow path and locations of the pickup and delivery stations in which we then provide a decomposition procedure based on a loop enumeration strategy coupled with a streamlined integer linear programming model. It is shown that only a small proportion of all loops have to be enumerated to reach an optimum. Therefore a truncated version of this algorithm should yield a good heuristic. Finally we propose a neighbourhood search heuristic method and report on its performance.

Article Outline

1. Introduction 2. Literature review and scientific contribution 3. Global formulation and solution methodology 3.1. Notations 3.2. Formulation 3.3. Solution of the global formulation 3.4. Test problems 4. Decomposition procedure 4.1. The feasible loop generation process 4.2. Undirected loop station location subproblem 4.3. Directed loop station location subproblem 5. Partial enumeration 6. Neighborhood search heuristic

7. Conclusions Acknowledgements References

物料处理系统的运输车辆/小车结构设计 调度控制

A Hybrid Fuzzy Knowledge-Based Expert System and Genetic Algorithm for efficient selection and assignment of Material Handling Equipment 专家系统 遗传算法 基于知识的模糊离散化采样 在高效物料处理设备中的应用 货物挑选、分拣和装运作业环境 Performance analysis of automated interbay material-handling and storage systems for large Wafer Fab

Layout design for flexible manufacturing systems considering single-loop directional flow patterns

A multi-objective model of operation allocation and material handling system selection in FMS design Indicators for measuring performances of morphology and material handling systems in flexible manufacturing systems

1,017 articles found for: pub-date > 1987 and tak(((Electric drum) or "Electric drum" or (Material handling)) and (Design or Selected or Production or Transmission or Manufacturing ))