CONSTRUCTION OF STEEL – SHELF. A RESEARCH PROJECT TOPIC ON CHEMICAL ENGINEERING
The steel-shelf was constructed at the mechanical Engineering workshop of the Institute.
The first step taken in the fabrication of the shelf was the selection of the material suitable for the construction; mild steel was chosen.
The construction has the following steps: drawing and dimensioning of the proposed steel – shelf, market surveying and procurement of the needed materials, marketing out and cutting of the material, welding, filling, and finally painting to prevent corrosion. The dimension of the steel – shelf are:
1219.2mm height, 939.8mm width and 457.2mm breadth.
The purpose is to produce a steel shelf that will be economically cheap and can meet up to the standard in the market.
A steel shelf is a set of shelves made of steel with compartments and partitions where books or files and other reference materials are kept in the libraries. It can be used to store chemicals and other laboratory equipments or apparatues in the laboratories. It can also be used to store other valuable materials at home and industries. When used in libraries for packing books it is called book shelf but if it is used in industries to store materials it is referred to as facility for storage.
A shelf can be made of wood, glass or metal (steel). It could be dismountable or undismountable. In consideration of some factors, we decided to design and fabricate an unddismountable steel shelf. This undismountable steel-shelf has a longer life span and serve its purpose better than any other shelf.
Being undismountable, there will be no lose of parts as in dismountable ones. Also, steel as a material of construction has advantage over wood which can be attached by termits; and glass which can easily be broken.
Though corrosion as a result of reaction of air (oxygen), moisture and chemicals do attack the surface of metals, painting of the steel was done in order to reduce or eliminate this problems of corrosion. Considering the availability durability, quality and affordability of this steels, research or the engineering properties of the material was carried out. Steel as a material of construction is the cheapest, the most common and the most versatile metal used in industries all over the world. It can be cast; drawn, hot or cold; rolled; pressed, welded etc.
There are many grades of carbon steel which includes: low. Carbon steel (mild steel) that contains. (0.1 – 0.3)% of carbon. It is of two types Black-mild steel and Bright-mild steel. Another is medium carbon steel which contain (0.3 – 0.7)% of carbon and High Carbon steel that contain (0.7 – 1.5)% of carbon.
In our project, low carbon steel or wild steel was used because it is used for general Engineering purpose. It has limited corrosion resistance, should not be used with dilute acids like sulphuric acid of less than 90% concentration. Even for concentration above 90%, the use of steel is still imited to certain ranges of temperature defined in accordance with the chemicals in contact with the steel. It does not all with stand hydrochoric, phosphoric or nitric acids irrespective of the level of temperature and concentration.