1.1 Introduction
Groundnut oil expelling machine is an important device for oil recovery from groundnut seed in a roller mill, direct firing of barrel and pressing with an engine driven oil expeller. Expeller use a horizontal rotating metal screw, which feeds oil-bearing seeds into a barrel shaped outer casing with perforated walls according to Maul et al (2011). The seeds are continuously fed to the expeller, which grinds, crushes and presses the oil out as it passes through the machine (Khangar and Jaju 2012). Groundnut is a very important oil seed and food crop around the globe based on its nutritional and trade values, it also serves as food for humans or livestock, and in the absence of meat, forms a valuable dietary protein component. The pressure ruptures the oil cells in the product and oil flows through the perforation in the casing and passes through the oil outlet and is finally collected with oil receiving container underneath.
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Limitations of the Study and Definition of technical terms.
1.2 Background of Study
Groundnut is a very important oil seed and food crop around the globe for its nutritional and trade values (Shankarappa et al., 2003). Oil is extracted from groundnut through either traditional means (mostly dependent on human energy with about 20-30% of the oil extracted) or mechanical means with over 30% of the oil been extracted (Olaomi, 2008). Most vegetable oils are recovered by grinding, cooking, expelling and pressing, or by solvent extraction of the raw materials. The most common method of extracting edible oil from oilseeds is mechanical pressing of oilseeds (Bamgboye et al., 2007).
Expeller are power driven, and are able to process 8 to 300kg of groundnut per hour or even more depending upon the type of expeller used (Khangar and Jaju, 2012). Bigger units which process greater quantities of oil are available for use in larger mills. The percentage of oil extracted by expellers is nearly 90% depending upon the type and kind of products as well as the expeller being employed. The friction created by the products being pressed wears down the worm shaft and other internal parts, and also have the tendency of creating problem or causes failure of main shaft.
The need to produce a groundnut oil expelling machine arose even in the distant past due to the need to produce oil for domestic and commercial uses. According to history, one of the major forces driving scholars into research is the desire to produce machineries that will be used for the production of food for man and animal (Bachman, 2001). Oil is extracted from groundnut through either traditional means (mostly dependent on human energy with about 20-30% of the oil extracted) or mechanical means (over 90% of the oil can be extracted) (Olaomi, 2008).
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to Design and Construct of Groundnut Oil Extraction or Expeller.
1.3 Statement of Problems
Investigation revealed that groundnut oil expeller has been developed and constructed by some researchers in different sizes, shapes and materials, mostly for industrial uses. Such expellers are expensive; involve high level technology which cannot be afforded by small scale and low income oil millers. In order to assist the small scale oil millers in the local communities, small scale groundnut oil expellers need to be designed, and constructed with locally sourced materials.
1.4 Aim and Objectives of Study
The aim of the study is to Design and Construct of Groundnut Oil Extraction. In achieving this aim, the following specific objectives were laid out as follows:
- To design, develop and test expeller that is affordable to small scale oil millers;
- To fabricate an improved, durable groundnut oil expeller, using local sourced materials; and
- To develop a machine that can extract oil from groundnut, within a minimum time frame.
1.5 Significance of Study
This study will be of immense benefit to other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.
1.6 Scope of Study
The scope of the research is focused on the Design and Construction of Groundnut Oil Extraction or Expeller.
1.7 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).
