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Showing posts with label Practicals. Show all posts
Showing posts with label Practicals. Show all posts

Refrigeration system-Construction and working of 'Ice plant'

We all are aware of domestic refrigerator and its usage. We get ice cubes from freezer compartment to meet daily requirements but to get ice in huge quantity we normally approaches the ice plant or factory. Here, I am going to share overview of construction and working of ice making process and its layout. 

Normally, any refrigeration system consists of four main equipments:

1. Compressor
2. Condenser
3. Throttle valve/flow control valve
4. Evaporator

Construction of Ice plant
But in Ice plant or factory, two additional circuits help us to create ice in huge quantity. Refer to the figure and Video.

'Bomb Calorimeter' for determination of Calorific Value of solid and liquid fuel

Calorific value (CV) of a fuel is a characteristic of fuel which is defined as the energy liberated per kg of fuel burnt. Fuels are found in three phase viz. solid, liquid and gaseous. Junker's calorimeter is used to measure the CV of gaseous fuels.

Bomb Calorimeter experiment to measure calorific value of fuel:
  • It is used to measure the calorific value (CV) of solid as well as liquid fuel. But to determine the CV of gas, one need to choose Junker's calorimeter.
  • A calorimeter contains thick walled cylindrical vessel and it consists of the lid which supports two electrodes which are in contact with fuse and fuel sample of known weight. 
  • The lid also contains oxygen inlet valve through which high-pressure oxygen gas (at about 25 to 30 atm) is supplied.
  • Entire lid with fuel sample is now held in a copper calorimeter containing known weight of water. A mechanical stirrer is provided to stirred well for uniform heating of water. 
  • A thermometer is also provided to measure the change in temperature of water due to combustion of fuel in Lid. 

Determination of viscosity by 'Redwood Viscometer' - Thermodynamic Practical

Viscosity: It is a measure of resistance offered by one layer of fluid to the other layer of the same fluid during motion.

Redwood Viscometer is normally used for determination of viscosity of petroleum products. 

'Redwood Viscometer' determines the viscosity in terms of seconds (which are terms as Redwood seconds), a time taken by oil to pass through a standard orifice and collection of the same oil in 50 cc flask.

Originally Redwood Viscometer was developed for measurement of viscosity of petroleum products.

'Redwood Viscometer' are of two types:

1. Redwood Viscometer No.1 (For fluid having viscosity corresponds to Redwood seconds less than 2000)
2. Redwood Viscometer No. 2 ( For fluid having viscosity corresponds to Redwood seconds greater than 2000)

Practical List for Heat and Mass Transfer (5th Semester Mechanical, SVNIT, Surat)

This article is all about giving a brief overview of all heat and mass transfer practicals during Vth semester of Mechanical Engineering. The practical list belongs to  modes of heat transfer likes

  • Conduction
  • Convection
  • Radiation
  • Heat exchanger as application of heat transfer

CalibraCopper-Constantannstantan Thermocouple
    • This experiment deals with the calibration of a given sample of Copper-Constantan Thermocouple by using different known value of temperature and exposing measurement junction to all these temperatures like steam point, Naphthalene Point, Oxygen Point, Sulphur Point, Silver and Gold Point. The Ice works as reference junction.

Thermodynamics Experiment: 'Grease Penetrometer'

Aim: To find out the consistency of given sample of grease.

What is Consistency of Grease?
- Measure of relative hardness of grease is referred as consistency number as per N.L.G.I (National Lubricating Grease Institute) which is a trade association that governs lubrication and related industry research.

 What is Grease?

Importance of 'flash point' and 'fire point'

In many engineering applications, fuels are used for getting thermal energy by combustion of fuel. For example, in oil fired furnace, oil is ignited and heat is used for heating the metals to alter their properties. Fuel selection is also one of the most important part. One need to use and select fuel based on its properties like calorific value, density, viscosity, specific heat and flash/fire point. Now what is the meaning of flash point and fire point? 'Flash Point is a temperature and the property of a volatile lubricant/fuel which suggests when volatile lubricant/fuel gives off sufficient vapor when heated, it will start ignite for a moment but not lasts more than few seconds. 'Flash Point' requires ignition source whereas 'auto-ignition temperature' does not require source of heat. While 'Flash Point' depends on the vapor pressure of that lubricant/fuel and it increases as temperature of fuel/lubricant increases. Flash point and fire point can be determined experimentally by use of Cleveland's open apparatus and Abel's closed cup apparatus.