Farm Power and Machinery Important Study Content (1)

Farm Power and Machinery Important Study Content

Farm Power and Machinery Important Study Content

Sources of farm power:- There are different sources of farm power available in India which are classified as-

1. Human power
2. Animal power
3. Mechanical power (Tractors + Power tillers + Oil engines)
4. Electrical power
5. Renewable energy (Biogas + Solar energy + Wind energy)

1.Human Power:-

• Human power is the main source for operating small implements and tools at the farm, like chaff cutting, lifting of water, threshing, winnowing etc.
• An average man can develop maximum power of about 0.1 hp for doing farm work.

2.Animal Power:-

• Power developed by an average pair of bullocks about 1 hp for usual farm work.
• The average force a draft animal can exert is nearly one-tenth of its body weight.

3.Mechanical Power:- These engines are two types

1. Spark ignition engines (Petrol or Kerosene engine)
2. Compression ignition engines (Diesel engines)

4.Electrical Power:- Electrical power is used for water pumping, diary industry, cold storage, farm product processing, fruit industry and many similar things.

5.Renewable Energy:-

• It is the energy mainly obtained from renewable sources of energy like sun, wind, biomass etc.
• Renewable energy can be used for lighting, cooking, water heating, space heating, water distillation, food processing, water pumping, and electric generation.
• This type of energy is inexhaustible in nature.

Farm Power and Machinery Important Study Content

Usage of renewable energy sources

1.Solar energy:- Solar dryers, lantern, cooker, solar still, solar refrigeration, solar lighting etc.
2.Wind energy:- Water pumping, electricity generation etc.
3.Biomass energy:- Gasifiers to produce producer gas, pyrolysis to produce liquid fuels, Biogas etc
4.Tidal energy:- Electricity generation
5.Geothermal energy:- Heat and electricity production

Wind energy

• The minimum wind speed 10km/hr required for agricultural purpose
• In India wind energy mainly Successful in Karnataka, maharstra,
  Gujrat.

Types of Windmill

1. Horizontal axis rotor
2. Vertical axis rotor

1. Horizontal axis rotor

A. Multiblade type rotor:- Having 12 – 20 blades.

B. Sail Type unit:- Runs at 60 – 80 revolutions per minute

C. Propeller type unit:-

• 2 – 3 aerofoil blades and runs
• speed 300 – 400 revolutions per minute.

2. Vertical axis rotor:-

a) Savonius type:- require large area
b) Darrieus type:- require less area.

Note:- both run independently of the direction of wind.

Heat Engine:-

• Heat engine is a machine for converting heat, developed by burning fuel into useful work.
• It can be said that heat engine is equipment which generates thermal energy and transforms it into mechanical energy.

Classification Of Heat Engines

1. Based on combustion of fuel

1. External combustion engine
2. Internal combustion engine.

1.External combustion engine:- Here, the working medium, the steam, is generated in a boiler, located outside the engine and allowed in to the cylinder to operate the piston to do mechanical work.

2.Internal combustion engine:- In internal combustion engine, the combustion of fuel takes place inside the engine cylinder and heat is generated within the cylinder.

2. Based on fuel used:- There are 3 types
1.Diesel engine:- Diesel is used as fuel.
2.Petrol engine:- Petrol is used as fuel.
3.Gas engines:- Propane, butane or methane gases are used.

3. Based Ignition Of Fuel

1. Spark ignition engine (Carburetor type engines).
2. Compression ignition engine ( Injector type engines).

1.Spark ignition Engine:-

• A mixture of air and fuel is drawn in to the engine cylinder.
• Ignition of fuel is done by using a spark plug.
• This combustion is called constant volume combustion (C.V.C.).

2.Compression Ignition Engine:-

• In compression ignition engines air is compressed in to the engine cylinder.
• Due to this the temperature of the compressed air rises to 700-900 C.
• This type of combustion is called constant pressure combustion (C.P.C.).

4. Based on working cycle

1. Four stroke cycle engine.
2. Two stroke cycle engine.

Farm Power and Machinery Important Study Content

Important Terminology 

I.C. Engine:- I.C. engine converts the reciprocating motion of piston into rotary motion of the crankshaft by means of a connecting rod.

Suction stroke:-

• During suction stroke inlet valve opens and the piston moves downward.
• Only air or a mixture of air and fuel are drawn inside the cylinder.
• The exhaust valve remains in closed position during this stroke.
• The pressure in the engine cylinder is less than atmospheric pressure during this stroke.

Compression stroke:- During this stroke the piston moves upward. Both valves are in closed position.

Power stroke:-After ignition of fuel, tremendous amount of heat is generated, causing very high pressure in the cylinder which pushes the piston downward.

Exhaust stroke:- 

• During this stroke piston moves upward.
• Exhaust valve opens and exhaust gases go out through exhaust valves opening.
• All the burnt gases go out of the engine and the cylinder becomes ready to receive the fresh charge.
• During this stroke inlet valve remains closed.

Compression ratio:- It is the ratio of the volume of the cylinder at the beginning of the compression stroke to that at the end of compression stroke, i.e. ratio of total cylinder volume to clearance volume.

Power:-  

• It is the rate of doing work.
• S.I. unit of power is watt.
• Watt = Joule/sec. (4.2 Joules = 1 Calorie).
• In metric unit the power can be expressed in kg.m/sec.

Horse power (HP):–

• It is the rate of doing work.
• Expressed in horse power.
• Conversion factors from work to power 4500 kg m of work /minute = 1.0 hp
• 75 kg. m of work /second = 1.0 hp.

Calorific value of fuel:- The heat liberated by combustion of a fuel is known as calorific value or heat value of the fuel. It is expressed in kcal/kg of the fuel

Name of fuel	Calorific value, kcal/kg	Thermal Efficiency
Light Diesel Oil (L.D.O)	10300	30%
High speed diesel oil (HSD)	10550	41%
Power kerosene	10850
Kerosine	9600 kcal/l	48%
Petrol	11100 kcal/ kg	20-37%
L.P gas	27700 kcal/m3	60%
Coal	8300 kcal/kg	20%
Charcoal	7000 kcal/kg	29%
Bio gas	4500 kcal/m3	60%
Fire Wood	4000 kcal/kg	20%
Cow dung cakes	22130 kcal/kg	11%

Carburetor:- The process of preparing air-fuel mixture away from the engine cylinder is called carburetion and the device in which this process takes is called carburetor.
Functions of carburetor

1. To mix the air and fuel thoroughly
2. To atomize the fuel
3. To regulate the air- fuel ratio at different speeds and loads on the engine.
4. To supply correct amount of mixture at different speeds and loads

COMPARISON OF DIESEL ENGINE WITH PETROL ENGINE

Diesel engine	Petrol engine
It has got no carburetor, ignition coil and spark plug.	It has got carburetor, ignition coil & spark plug.
Its compression ratio varies from 14:1 to 22:1.	Its compression ratio varies from 5:1 to 8:1.
It uses diesel oil as fuel.	It uses petrol (gasoline) or power kerosine as fuel.
Only air is sucked in cylinder in suction stroke.	Mixture of fuel and air is sucked in the cylinder in suction stroke.
It has got fuel injection pump and injector	It has got no fuel injection pump and injector, instead it has got carburetor and ignition coil.
Fuel is injected in combustion chamber where burning of fuel takes places due to heat of compression.	Air fuel mixture is compressed in the combustion chamber when it is ignited by an electric spark.
Thermal efficiency varies from 32 to 38%	Thermal efficiency varies from 25 to 32%
Engine weight per horse-power is high.	Engine weight per horsepower is comparatively low.
Operating cost is low.	Operating cost is high.
Compression pressure inside the cylinder varies from 35 to 45 kg/cm2 and temperature is about 500°C.	Compression pressure varies from 6 to 10 kg/cm2 and temperature is above 260°C.

Different Type Sowing Methods

(i) Broadcasting:- Broadcasting is the method of random scattering of seeds on the surface of seedbed. It can be done manually or mechanically.

(ii) Dibbling:-

• Dibbling is the process of placing seeds in holes made in the seedbed and closing the seed with soil.
• In this method, seeds are placed in holes made at definite depth at fixed spacing.
• The equipment used for dibbling is called dibbler.

(iii) Seed dropping behind the plough:-

• A woman/ man walk behind a plough.
• ploughing the land and drop the seeds in the furrows made by the plough.
• Sowing behind the plough can be done by a device known as malobansa .

(iv) Drilling:-

•  Drilling consists of dropping the seeds in furrow lines in a continuous stream and covering them with soil.
• This method is very helpful in achieving proper depth of sowing, proper spacing between seeds and proper seed rate.

(v) Transplanting:-

• Transplanting consists of rising the seedlings in a nursery bed and then planting the seedlings in another field (main field).
• It is commonly done for paddy, vegetable and flowers.
• It is a time consuming operation.
• Equipment used for planting the seedlings in the main field is called transplanter.

(vi) Hill dropping:-

• In this method, few seeds are dropped as a hill at a fixed place and not in a continuous stream.
• The spacing between hill to hill in a row is constant.
• The equipments are called planters.

(vii) Check row planting:-

• It is a method of planting, in which row-to-row and plant-to-plant distance is uniform.
• A machine used for check row planting is called check row.

Seed Cum Fertilizer Drill:- Seed drills fitted with fertilizer dropping attachments are called seed-cum-fertilizer drills, They deliver both the seeds and fertilizers simultaneously in an acceptable pattern.

Terms Connected With Harvesting Operation

1.Mower:- It is a machine use to cut herbage crops and leave them in a swath.

2.Reaper:- It is a machine to cut grain crops.

3.Reaper binder:- It is a machine which cuts the crops and ties them into neat and uniform bundles.

4.Sickle: -It is a curved steel blade with sharp edge in the inner side and a handle. It is used by human power. The person holds the tool and shears the straw or stalk and harvests the crop

5.Swath:- The harvested material laid on the land by the machine when harvesting is in progress is called a swath.

6.Windrow It is a row of material formed by combining two or more swaths.

7.Windrower:- It is a machine to cut crops and deliver them in a uniform manner in a row.

8.Combine:- It is a machine, which performs the functions of a reaper, thresher and winnower.

Farm Power and Machinery Important Study Content