Sarhad Dairy Case Study

LIST OF FIGURES

1 .Sarhad Dairy Plant , Lakhond

2 .General Layout of Dairy Plant 3 .Boilers

5 .Type of Boiler

6 .Atmospheric fluidized Bed Combustion 7. Boiler Tube

8. In bed Evaporator Bed Coil

9. Wear & Tear of Boiler Tube 10 Corrosion of Boiler Tube

1. INTRODUCTION

Company Overview

Fig 1. Sarhad Dairy Plant, Lakhond (Kutch)

Kutch district co-operative milk producer’s union ltd. “Sarhad Dairy” was established in year 2009. It’s registered under co-operative society’s act 1961, having reg. number 38861-09 dated 28 /07/2009. Sarhad dairy is the member of “gcmmf” Amul Anand. Its primary activity is to collect milk

When gas or air is passed through an inert bed of solid particles like sand supported on a perforated plate, initially the air will seek a path of least resistance and pass upward through the sand. With velocity goes on increasing, the air starts bubbling through the bed and the groups of atoms i.e (particles) gains the state of high turbulence. Under such conditions, the bed assumes the shape of a fluid and exhibits the properties associated with a fluid and hence the name 'fluidized bed'.

WORKING

DESIGN OF FLUIDIZED BED

Based upon the boiler heat, the proportion of fuel to be burnt is decided. On the basis of chemical composition of fuel, the requirement of air for combustion is calculated. As the combustion carried out in the bed all the heat is released within the bed itself. The heat is extracted from the bed by the leaving flue gases and the bed evaporator tube. The cross sectional area of bed is fixed based on the fluidization velocity which will not goes more than 2.8m/s. Because less the heat release rate, lower will be the bed temperature. Thus the temperature of the bed is still ensured for steady fuel combustion. In addition compartmentalization is carried out to ensure the minimum fluidization is

This, in short, is fluidized bed combustion. While it is necessary that temperature of bed should be at minimum equal to the ignition temperature of fuel and it should not be allowed to approach ash fusion temperature (1050°c to 1150°c) to avoid melting of ash. This is achieved by extracting heat from the bed through evaporator tubes immersed into bed. If velocity is less, fluidization will not takes place, and if the gas velocity is high, the groups of atoms i.e. (particles) will be entrained into gas stream and lost. Hence, to achieve the stable operation of the bed, it must be verified that gas velocity should be constant between minimum fluidization velocity and groups of atoms entrainment velocity. In a circuit, the circulation carry because of difference in density between the cold water in the down comer circuit and the density of hot gases water mixture in the evaporator tube. The flow will goes on increasing the heat input is more and the density of hot gas water mixture goes on decreasing in the evaporative