eChapters

Introduction

The procedure of making or building casting in the sand mould cavity or any other material is known as a foundry. This is the cheapest method of shaping the metal. Foundry exercise offers the technique of creating casting in moulds shaped in both sand or different material. A foundry is a manufacturing plant where castings are created by softening metal, emptying fluid metal into a shape, then, at that point, permitting it to harden. Regardless of whether we have not at any time been to a foundry or even know what one resembles, we are encircled by the metal castings. There is a decent possibility that we are perusing this under 10 feet from one.

Moulding

Introduction

Welding is a fabrication process in which two or more materials or metal pieces are joined or fused with the application of heat, pressure, or both allowing them to cool and this causes fusion. Besides the work piece, a filler material is also sometimes added to the joint to form a pool of molten material that cools to form a joint based on welding and that will be stronger than the parent metal.

Arc Welding and its Types

It is a process of joining two metals using an electric current generated by the power supply, which gives the required amount of heat to metal pieces through which the metals melt and when the metal cools, which results in the binding of the two metals. In the case of this type of welding, the power supply is given, which creates an electric arc between the electrode and the metal rod. Both A.C. or D.C. power supplies can be used in arc welding and both consumable and non-consumable rods can be used.

Introduction

A sheet metal shop is a kind of workshop where different types of materials are used to make sheet metal and then it is flattened into thin sheets of desired shape and size. Sheet metals are used for the production of automobile bodies, utensils, almirah and cabinet appliances, etc.Sheet metal parts have many advantages, like they are less expensive, lighter in weight and can be modified into versatile shapes. Low-carbon steel is commonly used. The use of casting and machining is being replaced by metal stamping. The stamping press is a kind of machine tool in which most of the operations occur, and the sheet metal products which are obtained by the machine are called stampings.

Study of Carpentry Hand Tool

Introduction

The process of making the wooden components is called carpentry. Carpentry deals with the mechanical work of making wood components such as making beds, roofs, wardrobes, tables, cases, utensils, floors, etc. It manages the structure work, furniture, cabinet making and so on joinery, i.e., preparation of joints is one of the significant activities in all wood works.

The products produced are used in making furniture, musical instruments, and building constructions like doors, windows, desks, chairs, cupboards, etc., of a place utilizing a specific kind of wood with the help of tools known as carpentry tools. Different wooden pieces are connected to make a useful product. Wood is used to make furniture, boxes, doors, windows, industrial floors, stairs, pencils etc.

1. Introduction

Thermal processing treatments are the conventional methods that have been broadly employed in the food industry to guarantee the microbiological safety of food materials at a minimal cost. However, these thermal treatments cause undesirable changes in flavor, nutritive value, texture, or color of the finished product that impact food quality (Pan et al., 2017). Growing the modern consumer’s demand towards the minimally processed and “fresh-like” taste foods has challenged the food industry to develop novel non-thermal preservation techniques as an alternative to thermal processing. 

1. Introduction

Heat transfer from a hot surface is a general method or technique of heating liquids and slurry type of food materials. In such cases the heat can be generated either directly by a heating element or indirectly from a hot medium like steam or hot water via a heat exchanger (e.g. shell and tube, plate). Therefore, for the heat transfer during heating by these techniques a temperature gradient will be required, which usually causes the fouling on the surface of the heating element or heat exchanger. Afterwards the fouling not only reduces the heat transfer rate but also results in quality deterioration within the product which is being processed. 

1. Introduction

Thermal processing used extensively in the food industry for preservation and shelf life extension of the products (Arnoldi 2001). Heat treatments remain most important in food processing unit operations, not only to achieve desirable changes in eating quality but also for preservative effect by inactivation of microorganisms, destruction of enzymes and insects.Heat is applied in various unit operations through adifferent mode of heat transfer such as conduction, convection, and radiations. 

1. Introduction

Extrusion of foods is an emerging technology for the food industries to process and market a large number of products of varying size, shape, texture and taste. Extrusion cooking of cereals is becoming more adaptive due to its various advantages over the traditional food processing techniques (White, 1994). Nowadays the extrusion of food is of major importance in the food-processing sector and it is the only process, which covers a wide range of food products such as ready to eat (RTE) breakfast cereals, snack foods, baby foods etc. Elaborate scientific research, technological development and engineering design, which have been done in this field so far, have led to large-scale industrial production. 

1. Introduction

Membranes separation processes have gained widespread applications in food industry. High selectivity of membrane has been exploited for separating a particular component from complex liquid food mixture and for controlled release of active ingredients like preservatives or flavor compounds. Today, a number of chemical processes utilizing the unique properties of membrane have been developed for commercial application in food industry with specific advantage of low energy requirement. Membrane separation/molecular sieving is one among those food engineering principals which has found broad range of applications including concentration of heat labile compounds, recovery of solvent, downstream processing, flavor volatile recovery, deacidification, desalination, waste water treatment etc

1. Introduction

Foods available in nature and, in some cases, the products made from it thereof contain quite an amount of water. This water not only adds volume to the food products but also provides a sight for attack by the micro organisms. Also, removal of water becomes essential if this water interferes with the end product chracteristics. There are several processes in food industries which are designed to get rid of this excess water, such processes are called concentration processes. The processes which can remove water from food substances are,- evaporation, freeze concentration and membrane based processes. All these process have their limitations in rendering solid content to the final product (Fig. 1). Perhaps, these limitations can be overcome by combinig the processes.

The objectives that are fulfilled by the concentration processes can be enumerated as follows:

1. Introduction

To maintain good quality of product & shelf life, it is very important & essential to concentrate on Cleaning & Sanitization process at plant level & to follow the CIP process properly. An attempt is made in the current chapter to present details pertaining to cleaning in fluid milk and milk products manufacturing & processing plants. This chapter will be helpful the students of Food & Dairy Technology for better understanding the process milk plant cleaning & sanitation technology.

1. Introduction

Milk is a source of abundant nutrition has been a vital part of human civilization since prehistoric times. However, because of its perishable nature, it requires immediate processing to improve the shelf life and safe consumption .With the advancement of processing techniques in dairy and food processing, there is a widespread option being utilized to improve the milk shelf life byeither thermal technologies (pasteurization, sterilization, and ultra-high temperature) or nonthermal technologies (high pressure processing, high pressure homogenization, pulse electric field and ultra sonication). Still, pasteurization and sterilization are the two foremost process is used for milk industries. Pasteurization is the thermal inactivation of microorganisms at temperatures below100°C that enhance the safety and quality of milk and milk products and extends the shelf life to an extent. 

1. Introduction

Freezing is a method of food preservation that involves lowering the temperature below the freezing point of food generally -18 °C or below. During freezing of food the water present in them changes its state to form ice crystals. Human beings in the colder regions have used freezing as a means of preservation since they learnt hunting and gathering foods. The foundation of the modern frozen industry was laid in mid 1920 when Clarence Frank Birdseye, an American inventor used cold brine solution to chill packaged fish and extended it further for quick freezing of meat poultry fruit and vegetables. 

1. Introduction

Mixing is a fundamental and widely practiced operation in many fields, such as chemical, pharmaceutical, and food processing industries. The mixture’s primary aim is to increase the homogeneity of the material in bulk (Uhl and Gray, 1986; Patterson et al., 2004). Mixing means the random distribution of two or more ingredients throughout a system, which differs from the term’ agitation,’ which is defined as establishing a particular flow pattern with the liquid, especially in a circulatory motion within a container. Mixing is a necessary step in the context of food processing operations. 

1. Introduction

Raw milk is an emulsion. It is a mixture of milkfat globules, Solid Not Fat (SNF) and water. Over time, milkfat globule separate out from milk serum and comes to the surface of milk as a layer of cream due to the low density of milkfat or due to heating of milk. When milk is heated rapidly and continuously, some of the water in it evaporates from the surface. This exposes proteins and fat molecules, which bind and dry out and forms a skin like film on the surface. 

1. Introduction

Size reduction is applied to all the ways in which particles of the solids are cut or broken into smaller pieces. Size reduction operation of solids is referred to as 'Comminution", some of the common comminutive processes are - crushing, grinding, milling, mincing, and dicing. Breaking down of large sized particles of food substances into smaller particles is a common unit operation in many food processes, e.g. wheat flour, turmeric powder, spices, etc. are mostly used in powdered form. Some ofthe common objectives that are fulfilled by size reduction are:

1. Introduction

Cleaning and grading are the first and vital post harvest operations undertaken to remove foreign and undesirable materials such as crop seed, chaff, mud, stones, straws, immature grains, dust, husk and even iron and steel particles from grains as well as fruits and vegetables and to separate the products into various fractions. Generally, the hand threshing and the traditional handling used in most developing countries cause a larger percentage of foreign matter with these crops. Thus, more cleaning is required. Cleaning is essentially a separation process, in which some difference in physical properties of the contaminants and the food units is exploited. 

1. Introduction

Refrigeration may be defined as the process of achieving and maintaining a temperature below that of the surroundings. The aim being to cool some product or space to the required temperature. Refrigerated system or a room system is maintained at a temperature which is lower than the atmospheric temperature. Due to higher temperature of atmosphere, heat enters the system. To keep the temperature of the system constant, heat must be removed continuously from the system. Heat removed must be equal to the heat transferred to the system. One of the most important applications of refrigeration has been the preservation of perishable food products by storing them at low temperatures. Refrigeration systems are also used extensively for providing thermal comfort to human beings by means of air conditioning.

1. Introduction

Thermodynamics is science of energy and may be defined as “The branch of science which deals with the Interoction between the heat and work is referred as Thermodynamics

’Thermo’ means heat and ’dynamics’ means motion. It deals with energy interaction when work is converted into heat energy or vice versa. Precisely, thermodynamics may be defined as a science which deals with energy transformation from one form to another and dealing with relationship among the properties ofthe system. In power plants, internal combustion engines, boilers, nozzles, diffusers etc. are the example where heat is converted into work. In compressor, turbine, cooling of engines by water, application of brakes in a vehicle etc. are the examples where work is converted into heat.