Cement Equipment Research Articles

The Low-Carbon Scheduling Optimization of Integrated Multispeed Flexible Manufacturing and Multi-AGV Transportation

As low-carbon and sustainable manufacturing becomes the mainstream development direction of the current manufacturing industry, the traditional heavy industry manufacturing enterprises in China urgently need to transform. For the heavy cement equipment manufacturing enterprise investigated here, there is a large amount of energy waste during the manufacturing operation due to scheduling confusion. In particular, the multispeed, multi-function machining and the transportation of multiple automated guided vehicles (multi-AGV) are the main influencing factors. Therefore, this paper addresses a novel low-carbon scheduling optimization problem that integrated multispeed flexible manufacturing and multi-AGV transportation (LCSP-MSFM & MAGVT). First, a mixed-integer programming (MIP) model is established to minimize the comprehensive energy consumption and makespan in this problem. In the MIP model, a time-node model is built to describe the completion time per workpiece, and a comprehensive energy consumption model based on the operation process of the machine and the AGV is established. Then, a distribution algorithm with a low-carbon scheduling heuristic strategy (EDA-LSHS) is estimated to solve the proposed MIP model. In EDA-LSHS, the EDA with a novel probability model is used as the main algorithm, and the LSHS is presented to guide the search direction of the EDA. Finally, the optimization effect and actual performance of the proposed method are verified in a case study. The experimental results show that the application of the proposed method in actual production can save an average of 43.52% comprehensive energy consumption and 64.43% makespan, which effectively expands the low-carbon manufacturing capacity of the investigated enterprise.

China's cement demand and CO2 emissions toward 2030: from the perspective of socioeconomic, technology and population.

China is the largest cement producer and carbon dioxide (CO2) emitter in the world. The country has attracted too much attention in calculating and comparing its CO2 emissions. However, as the second largest CO2 emitter after the fire power industry, China's long-term cement demand and cement-related CO2 emission projections were not fully studied. The Chinese government, however, committed that by 2020 and 2030, China's per capita GDP of CO2 emissions would be lower than that in 2005 by 40-45% and 60-65%, respectively. In this paper, China's cement demand in 2030 was projected based on the population size, urbanization rate, fixed assets investment, and per capita GDP. Furthermore, decoupling study in China's cement industry was also involved based on the GDP and CO2 emissions during 2001-2015. We also used the diffusion rate of 12 types of CO2 reduction measures and two changed scenarios of clinker-to-cement ratio, to project the cement CO2 emission factors toward 2030 after determining the accounting scope. Meanwhile, the CO2 emissions of China's cement industry through 2030 were projected naturally. The results showed that China's cement output in 2030 will be approximately 2000, 1650, and 937 Mt. based on the fixed assets investment, urbanization rate, and per capita GDP respectively. The projected two scenarios cement CO2 emission factors were resp. 407.83 and 390.02kg CO2/t of cement which were 42.6 and 45.1% lower than that in 2005. The cement CO2 emissions were projected to be in the range of 366 to 818 Mt. in 2030. Additionally, China's total cement output value has been decoupling from cement CO2 emissions from 2012, which is mainly attributed to eliminating backward capacity, reducing excess capacity or the declining cement output. And decoupling economic from China's cement CO2 emissions may change to be strong or weak decoupling in the near future. As cement production is one of the factors effecting cement CO2 emissions, the most important measure for controlling cement CO2 emissions is a reasonable capacity utilization rate. It is therefore important to control the growth of cement CO2 emissions by regulating the capacity utilization rate within a reasonable range. Eliminating backward capacity, removing excess capacity, controlling new capacity, staggered production, and the "going global" of cement equipment can have great impacts in controlling the total amount of cement output and CO2 emissions.

Optimal design of helical reducers for cement equipment

The trends in raising the technical level of multistage helical reducers for drives of cement, metallurgical and other heavy equipment are considered. An interactive method for optimizing the geometrical parameters of reducers with various gear ratios is proposed, which ensures equal strength of the stages in contact and bending endurance. It is shown that an increase in the hardness of the teeth requires an increase of the module and helical angle of the teeth, limitation of gear ratios, and to reduce the difference in center distances of adjacent stages. When creating a new generation of reducers, the transition to gears with carburized teeth leads to an increase in load capacity of 2.5-3 times. The examples of gear drive design for rotary kilns and ball mills are considered.

Research kinetic of motion of milling bodies in ball mill, outfit heat-exchange unit and calculation of its energy performance

The article considers topical issues of energy saving in cement production with the use of a technological grinding complex, which includes a press roller grinder and a ball mill. Rational conditions of grinding are proposed for pre-shredded material through the installation of blade energy exchange devices (BEED) in the mill drum. The loading level in the first chamber varies periodically depending on the drum rotation angle, equipped with BEED. In the zone of BEED’s active action, there is a “scooping” of a part of grinding bodies together with crushed material, raising them to a height and giving them a longitudinally transverse movement, which is different from movement created in the mill without BEED. At the same time, additional work that consumes engine power is being done. A technique is proposed for calculating the additional engine power consumption of a mill, equipped with a BEED. This power is spent on creating a longitudinal-transverse motion of grinding bodies and its first and second chambers in areas of active influence of the BEED. Comparative analysis of results obtained experimentally and calculations of proposed equations show a high convergence of results. These analytical dependencies may be interest to Russian and foreign organizations that carry out their activities in the field of design and manufacture of cement equipment, as well as to cement producers.

An outsourcing service selection method using ANN and SFLA algorithms for cement equipment manufacturing enterprises in cloud manufacturing

In cloud manufacturing (CMfg) environments, an increasing number of manufacturing enterprises outsource manufacturing activities to subcontractors that are more professional to focus on the development of their core business. Volume, diversity, and variety are the typical characteristics of outsourcing services for cement equipment manufacturing enterprises (CEMEs). To address the new problem of service discovery and combinatorial optimization of outsourcing resources (COOR), a novel heuristic approach is investigated in this paper. First, a clustering and searching model of a web outsourcing service based on Ontology Web Language for Services (OWL-S) and an artificial neural network (ANN) is established. Then, an improved shuffled frog leaping algorithm (SFLA) is developed to solve the COOR problem. Finally, an investigation and comparative experiments based on a group of cement equipment manufacturing companies is presented. The experimental results show that the proposed method is preferable and is more efficient for solving large-scale problems in a CMfg environment.

Manipulating cement-steel interface by means of electric field: Experiment and potential applications

Good shear bonding and hydraulic bonding between cement and steel play a crucial role in well integrity of oil and gas wells. In this experimental study, we investigate the effect that constant electric field may have on the bonding at cement-steel interfaces. Constant voltage (18 V) was applied between two stainless-steel electrodes immersed into a cement slurry. It was found that bonding was significantly improved at the positive electrode, while it was significantly worse at the negative electrode. The effect was due to the negatively-charged cement particles being attracted to the positive electrode. The effect may potentially be used for manipulation and control of casing-cement and reinforcement-concrete bonding strengths in oil & gas and construction industries, respectively. Side-effects that might reduce the applicability of this technology, are gas production at both electrodes (and especially at the negative one) and significant corrosion at the positive electrode due to electrochemical reactions at metal surfaces. Poor bonding at the negative electrode may potentially be used for cleaning of cement equipment, such as cement pumps, pipes, tanks, and mixers used on the rigs to perform well cementing jobs in oil & gas industry.

Service requirement conflict resolution based on ant colony optimization in group-enterprises-oriented cloud manufacturing

Cloud manufacturing (CMfg) platform for group enterprises (GE) is a kind of private CMfg, which is to integrate and optimize GE’s internal resources and capacity for large complex equipment manufacturing. The platform makes a connection between distributed and heterogeneous manufacturing resources to build a virtual pooling of resources for the group. However, it is evident that uncertainties and dynamics inherently exist in the platform and it causes manufacturing service requirement conflict among multiple projects. In order to address this issue, the management process of large complex equipment manufacturing project in GE-oriented CMfg platform is described. And next, this paper analyzes the causes and characteristic of service conflict in the platform. Then, a multi-objective mathematical model of conflict resolution is proposed. The proposed model considered both global target of shortest duration and partial target of tasks change minimization. Moreover, a method based on serial schedule generation scheme (SSGS) and ant colony optimization (ACO) algorithm is put forward to solve the model. Finally, a conflict resolution case study in a cement equipment manufacturing group enterprise is provided to illustrate the application of the proposed the model and algorithm.

An optimizing model to solve the nesting problem of rectangle pieces based on genetic algorithm

In the process of cement equipment manufacturing, the demand of rectangle pieces of steel structure is very large. The traditional manual nesting, which is simply cutting by hand-making according to the arrangement of the number and size, causes the low efficiency and material wasting. To solve the problem above, this paper proposes an optimizing model for nesting problem of rectangle pieces. Firstly, with the aim of the maximum utilization ratio of the sheet, the optimization mathematical model for nesting problem of rectangle pieces is established. The lowest horizontal line searching algorithm is described in detail. Secondly, the mathematical model is solved to get the optimal solution by the combination of genetic algorithm and the lowest horizontal line searching algorithm. In the solution process, this paper presents the methods of gene encoding and decoding, definition of fitness function, the design of genetic operators and the design of algorithm operating parameters. Finally, we use one sheet as an example to illustrate the proposed model and algorithm process. Experimental results have shown that the proposed approach is able to achieve rectangle pieces nesting with the maximum material utilization ratio.

A Pareto supplier selection algorithm for minimum the life cycle cost of complex product system

Supplier selection has significant impact on life cycle cost of complex product system (CoPS). In this paper, a new variant of supplier selection problem named life cycle supplier selection of CoPS (LSS&CoPS) problem is addressed. There are three kinds of choices for a manufacturer to complete a CoPS: self-made, purchasing the finished component and outsourcing. Different selection not only results in difference of procurement cost of CoPS, but also results in reliability changing after it delivered to customer which greatly influences the operating cost in CoPS’s lifecycle. However, the minimizing of two objectives is mutually conflicted. This paper presents a bi-objective LSS&CoPS model which considering operating stage of CoPS to balance the procurement cost and operating cost. Moreover, a hybridization of Pareto genetic algorithm (PGA) with multi-intersection and similarity crossover (MSC) strategy is proposed to solve the bi-objective problem. Also, a dual-chromosome is used to represent the variable-length chromosome. Finally, a cement equipment supplier optimal in a cement equipment enterprise is provided. Example indicates that the procurement cost and operating cost have been optimized, yields a Pareto optimal solution of supplier schema for project managers to make-decision and decrease the life cycle cost of CoPS. Additionally, the results show that the proposed approach is more preferably in Pareto optimal solution searching.

発電用ボイラ,クレーン,セメント設備での事例(リスクベースメンテナンスの具体例)(<小特集>リスクベース工学)

発電用ボイラ,クレーン,セメント設備での事例(リスクベースメンテナンスの具体例)(<小特集>リスクベース工学)

A New Technique for Evaluating Field Cement Mixing

Abstract Cement service companies have developed spacer systems to address various flow regimes, developed a wide array of mixing equipment and have written computer simulation programs to address a wide range of well parameters. Most of the simulation programs evaluate hole geometry, wash uts, eccentered casing, and U-tube effects. While these designs, developments and job simulations are desirable and necessary, it is important to understand the limitations of the available field mixing equipment and the ability of that equipment to deliver a cement slurry at the specified density and rates required by these designs. This study investigates the ability of existing mixing equipment to deliver a cement slurry at a specified density and rate. This paper takes data recorded on location and graphically presents it in a three dimension graph of rate, density and volume percentage. This differs from the data presentations available from the service companies. The graphs offered by the cement companies typically plot density, rate and pressure vs. job time. This is useful for determining the events during the job, but does not allow for analysis of the mixing characteristics of the cement unit. This paper presents three dimension histograms from several cement jobs, attempts to evaluate the mixing errors on those jobs, and outlines the efforts taken to correct the problems. A comparison is made to two dimensional histograms evaluating only the density variations. Also presented are data on some jobs where the main objective appears to be the control of the mixing rate, rather than density control. The majority of the data evaluated in this study is from offshore installations. This allows for in-depth evaluation of both the cement unit and the cement delivery system. For consecutive jobs, the same piece of equipment is used, thus eliminating some additional variables in the evaluation. The data reveals several trends in cement mixing. The types of mixing noted in this project are: (1) Mixing where the control of density and rate is very poor, (2) Rate controlled mixing where the mixing rate was the controlling factor, (3) Density driven mixing where concern over the slurry density took precedence over rate and (4) Density and rate control appear to be in concert. From the data evaluated, this analysis method allows for better evaluation of cement mixing, and the quantification of mixing characteristics of various pieces of cement equipment. It will allow for a direct evaluation of the value of adding specific pieces of mixing equipment such as averaging tanks, batch tanks, recirculating mixers, etc. Properly used, the presented evaluation technique should allow the operator to optimize the total cement mixing system through the selection of the most consistent mixing unit.