Cranes- Its types and classification...

Cranes- Its types and classification A crane is a machine which is having a hoist with a longitudinal and cross movement. The hoist of a crane consists of wire rope and hook. The crane is used both for lifting and lowering materials, and to move them horizontally. Cranes uses one or more simple machines to create mechanical advantage and thus move heavy loads. Many factors are taken into consideration while selecting a crane. These factors include lifting capacity, crane use and application and the number of work cycles that the crane is required to undergo. Types of cranes Cranes are of many types. Some of them are given below. Overhead cranes – An overhead crane is also known as a bridge crane. It is a type of crane where the hook and the line mechanism runs along a horizontal beam that itself runs along two widely separated rails usually in a long factory building and runs along rails along the building’s two long walls. These cranes include a hoist to lift the items, the bridge, which spans the area covered by the crane, and a trolley to move along the bridge. Overhead cranes typically consist of either a single beam or a double beam construction. These can be built using typical steel beams or a more complex box girder type. Double girder bridge cranes are more typical when needing heavier capacity systems from 10 tons and above. The advantage of the box girder type configuration results in a system that has a lower deadweight yet a stronger overall system integrity. A typical overhead crane is shown in Fig 1. Fig 1 A typical overhead crane Gantry crane – A gantry crane has a hoist in a fixed machinery house or on a trolley that runs horizontally along rails, usually...

Effective Communication – a tool for Organizational Success...

 Effective Communication – a tool for Organizational Success Communication is a process of transferring information from one person to another. It is commonly defined as ‘the imparting or interchange of thoughts, opinions, or information by speech, writing, or signs’. It is a two way process in which there is an exchange of information towards a mutually accepted goal or direction. Organizational communication is a channel for flow of information. This includes activities of sending and receiving messages through various layers of authorities using different message systems and discussing various topics of interest with the employees of the organization. Organization communication is shown in Fig 1. Fig 1 Organizational communication In present day scenario, communication is important for the functioning of an organization as well as for its success. The organization’s executives traditionally spend the majority of their time in communicating in one form or another (meetings, face to face discussions, inter office memos, letters, reports etc.). Today the necessity of communication is felt more and this necessity has engulfed most of the employees in the organization. The need of communication has increased in recent times since today’s work processes emphasize greater teamwork amongst the employees. Also for achievement of the short and long term objectives all organizations have to meet the challenges of internal and external communication. The nature of organizational communication is highly diverse. It spans communication at the micro, meso and macro levels. The communication practices include formal and informal communication, internal communication (meetings, work directions, reviews, presentations, internal correspondences and newsletters etc), externally directed communication (annual reports, press releases, interactions with stakeholders such as investors, customers, suppliers, social groups, statutory and public bodies etc), organizational learning, knowledge management, industrial relations, conflict management and use of information technologies. In small organizations the...

Air pollution control – Control of particulate emissions Aug28

Air pollution control – Control of particulate emissions...

 Air pollution control – Control of particulate emissions Steel plant has many metallurgical processes which take place at high temperatures. Further many of these processes handle raw materials some of them are in the form of fines. Hence all these processes are prone to emit pollutant gases and particulate matter into the atmosphere. This in turn affects the quality of air around the plant. In order to improve and protect the quality of air, different pollution control devices are used for reduction of the emissions. Earlier for many years, pollution control equipments were used only for those processes where the pollutants amounts were very high or they were toxic in nature. These equipments were also earlier used where they had some recovery value. But today, with the environment laws becoming more and more tighter and with the increasing concerns of the society regarding the environment, it has become necessary for the steel industry to look into its emissions and install equipments in all the areas to reduce the emissions to minimum possible levels. The emission control equipments are basically of two types (i) particulate emission control equipments and (ii) gaseous emission control equipment. This article describes the particulate emission control systems. All particulate emission control equipments collects particulate matter by mechanisms involving an applied force. Various particulate equipments are settling chambers, cyclones, bagfilters and electrostatic precipitators. The mechanisms of dust removal in these equipments and the applied force are given in Fig. 1 Fig 1 Mechanisms of dust removals Settling chambers  Settling chambers was one of the first devices used to control the particulate emissions. However it is very rarely used today since its effectiveness in collecting particles is very low. The collection force in settling chamber is gravity. Large particles moving slow enough...

Conveyor belts

Conveyor belts Conveyor belt is the most important element of a belt conveyor installation. The conveyor belt fulfils the task of absorbing the stresses developed at the drive start up, transport the load, absorbs the impact energy at the loading point, withstand temperature and chemical effects (heat, oil and acidity etc.) and meet safety requirements (flame resistance and antistatic etc.). The selection of the conveyor belt specification depends on its application. The schematic cross section of a plied conveyor belt is shown in Fig.1. Conveyor belt has the following components. Carcase – It consists of textile plies, steel weave or steel cord. Covers –  The cover is made up of either rubber or PVC of different qualities Additional components – These components of the conveyor belts are as needed and usually are edge protection, impact protection and longitudinal slitting prevention etc. Special construction elements – These are the profiles on steep incline belts, cleats, or corrugated edges etc. Fig 1 Schematic cross section of a plied conveyor belt Carcase The carcase of a conveyor belt can be made from various materials and in different construction. The most commonly used are textile ply carcases and steel cord.  Textile ply carcases are with one or more textile plies. The maximum numbers of plies can be up to 6 numbers. In monoply belts, a PVC impregnated textile carcase is used. Depending on tensile strength and duty, the carcase fibres are in polyester, polyamide or aramid. In the carcase of steel weave type, the transmission of force is by means of the longitudinal steel cords laid to one another in the same plane. Above this carcase is a transverse layer also of steel which is held in place by a polyamide binder cord. In carcase with steel cord,...

Quality Circles – An Effective Tool for Management...

Quality Circles – An Effective Tool for Management Quality circles consist of a basically formal, institutionalized mechanism for productive and participative problem solving interaction among the employees of an organization. Quality circles are made of groups of employees (normally 6 to 12) who perform similar tasks or share an area of responsibility. The groups meet on a regular basis, usually under the leadership of a supervisor and often with management, to discuss work related issues and to offer suggestions and ideas which when implemented not only improve the performance of the organization but also motivate and enrich the work of the employees. Quality circles operate on the principle that employee’s participation in decision making and problem solving improves the production methods and the quality. The characteristics of quality circles are that they consist of volunteers who set their own rules and priorities, take decisions by consensus and use organized approaches to problem solving. Quality circles activities should not be in the direction of fault finding. When matured quality circles become self managing, and gain the confidence of management. Quality circles enable the enrichment of the lives of the employees and create harmony and high performance. Typical work related issues are improvements in occupational health and safety, product design, manufacturing processes and improvement in the workplace. History Quality circles dates back to 1950s when they were first seen in the United States. But they were seriously developed and implemented by Dr Kaoru Ishikawa in Japan in 1960. The first quality circle was registered in 1962. Quality circles were re-exported to USA in the early 1970s. International Association of Quality Circles was formed in USA in 1977. BHEL Hyderabad was the first organization in India to start quality circles in 1982. Objectives of a quality circle...