Module 1. Introduction of dairy plant design and layout

Lesson 2

2.1 Introduction

Dairy Plant design, involves the estimation of capacity, process scheduling and proper layout so as to achieve the objective of handling milk at the least cost and greatest safety. However, the dairy industry and the plant design has to meet certain special requirements and need to be focused on these. The following are the few aspects that make the dairy industry as a unique one.

Special Characteristics of Dairy Industry:

  1. Perishable nature of milk: Milk is one of the most perishable of the agricultural commodities, and has only few hours of shelf life unless it is chilled and processed. Hence, the TIME factor is the most important aspect to be involved in the dairy plant design and lay out
  2. Milk is an essential commodity. It provides nutrition especially to children and aged. Hence the dairy industry has a high profile in the society, and its functioning is very essential to the well being of the society.
  3. Seasonal nature: The dairy industry has to deal with availability of raw milk fluctuations depending on the season. It is available in certain months, called Flush season when most of the calving and green fodder is available. During summer months, when milk availability dips due to most of the animals coming to end of their lactation period. Hence, OVER CAPACITY is the factor to be considered in plant design and layout, as the plant is to meet the peak procurement of the flush season, while in the remaining months it is having excess capacity. Also flexibility of the plant design and layout has to be considered.
  4. Milk is a food item, which has to be consumed, especially by children and old people. Hence, PLANT HYGIENE is the important factor in plant layout and design.
  5. Effluent disposal of dairy plant is essential as the volume and BOD value of the dairy effluent is high. Sufficient planning is required to handle this high volume of effluent to be handled by Effluent Treatment Plant (ETP).
  6. Dairy Industry has to meet the various legal aspects and mandatory requirements. It has to meet the Industrial act, Labour act, Boiler act, Pollution control act. It also has to meet the HACCP and FSSAI guidelines.

2.2 Importance and Economics of Plant Design

The products of dairy industry i.e., liquid milk, yoghurt, curds/dahi, cream, butter, ghee, ice-creams, cheese, milk powders, shrikhand, traditional Indian dairy products etc. are foods which are very important for human nutrition. Therefore, it is very necessary that the milk and milk products should be available to everyone at the lowest possible rate. Also the profit margin that the dairy entrepreneur expects is limited. Therefore, the capital outlay of the building and plant should be economical. Planning must be done wisely to make best use of the labour employed and to keep operating costs to a minimum. Materials and method used in building must be such as to give the longest practical life with the minimum maintenance, in spite of working conditions which are often relatively severe from both mechanical and chemical points of view. It should also be without stopping the production.

To extend the shelf-life some techniques like quick heating, quick cooling, acidification etc. are applied and also various advanced packaging techniques are used. The Dairy Technology starts with milk processing till the final products such as market milk and conversion into various products. So the subject Dairy Plant Design and Layout is the designing of layout plan for a dairy plant, i.e., layout for different sections in the dairy building, equipment layout, laying of dairy machines in such a manner that it allows efficient and economical movement of men and material in the plant in each section. The subject contains several applications of fundamental topics, such as locations site selection, building materials, specific requirements of each section including service sections.

2.3 Legal and Commercial Aspects of Plant Design

Care should be taken to provide adequate natural and artificial lighting. Every possible effort should be made to ensure that the building and the site will be pleasant to look at. The architect can provide a good landscape and an attractive outlook. The welfare of the employees must be kept in view. Canteen facilities are essential to meet the requirement of Labour act. Ultimately, the dairy plant layout requires careful thought and planning keeping in view manufacture of the products and their commercial aspects. A sound layout engineering contains allowance for increase in capacity by arranging the production departments and selecting the type of building that can be expanded at low cost. It should be easy to increase the output capacity which may be required in the future. A floor arrangement that contributes to the low cost production planning and control are achieved in good plant layout. Material control and steady amount of production capacity can be easily attained with minimum idleness of machinery and man. Finally leading to the delivery of products in short notices can be achieved.

Safety and good working conditions are very necessary in a proper plant layout. Minimized hazards at the working stations, in material handling, storage, maintenance operations and so on are features of good plant layout. Minimum man hour losses, reduction in capital equipment and material losses incorporate improved working conditions. Increased employee moral tends to reduce production costs and helps develop a stable operating force.

In planning the building, several important factors have to be studied in detail before the plant could be developed to the stage of construction. The size of the building and the floor space to be provided depend upon the processes and choice of appropriate steps, numbers and associated equipment to be accommodated and the most important factor of rearrangement of facilities in the initially built building and provision for expansion of the building without costly modifications. A high degree of sanitation is necessary to ensure protection from contamination, odours, chemicals, organisms, etc. This includes the interior and exterior of the building and sanitary conditions of the environment. Simple pleasing design with high utility value without undue importance to architectural factors is necessary.

Civil Engineering aspects of plant design : The type and methods of use of civil construction is evolving day by day. New materials are being developed to meet specific requirements of industries. The planning of civil construction is very much related now to meet the requirements of HACCP and FSSAI acts, which are more stringent in nature. Structural modules of RCC Columns and beams gives good flexibility in the location of the equipment and layout of service lines. The height of the ceiling is another important factor. Plain smooth surface of the underside of the ceiling with embedded fixtures for lighting and pipe supports, etc. , into the ceiling is best.

2.4 Advantages of a Good Plant Layout

1. A good layout reduces

a. the effort in normal material handling of a worker

b. cost of handling by direct labour and hence increased productivity per man hour and

c. indirect manufacturing cost by decreasing spoilage under difficult handling situation

2. It uses only essential space required and eliminate congestion and accident, permits flexibility for methods improvement and future expansion besides making supervision easier.

3. It also facilitates scheduling and despatching operation.

Last modified: Wednesday, 26 September 2012, 9:52 AM