STEPS FOR HEAT TRANSFER. H.T. FROM … ·  · 2008-08-08Lesson 2.2 SHELL&TUBE HEAT EXCHANGER. Lesson 2.2 1-2 COUNTER & PARALLEL ... HEAT EXCHANGER BY INDIRECT METHOD. ... Slide 1

• STEPS FOR HEAT TRANSFER.

H.T. FROM CONDENCED VAPOUR TO LIQUID BOILINGH.T. FROM HOT GAS TO LIQUID BOILINGH.T. FROM HOT LIQUID TO COLD LIQUID.H.T. FROM STEAM CONDANTATION TO HOT GAS

Lesson 2.1 HEAT TRANSFER MECHANISM

• Heat can be transferred from one phase to another phase. Heat transfer will take place in three ways.Conduction:Conduction: Transfer of vibrational energy from one molecule to another . Ex. Metal piece heated from one end. Convection:Convection: It can be occurs for the mixing of elements of fluid. Ex. Preparation of tea.

Lesson 2.1 HEAT TRANSFER MODES

•• Convection:Convection: It can be occurs for the mixing of elements of fluid. Ex. Preparation of tea.natural convection:natural convection: Naturally heated.forced convection:forced convection: Mechanical force applied.RadiationRadiation

Radiant energy transferred in the form of electromagnetic waves.

energy transferred from the sun.

Lesson 2.1 HEAT TRANSFER MODES

Lesson 2.2 DOUBLE PIPE HEAT EXCHANGER

Lesson 2.2 SHELL&TUBE HEAT EXCHANGER

Lesson 2.2 1-2 COUNTER & PARALLEL FLOW HEAT EXCHANGER

Lesson 2.2 2-4 COUNTER & PAPALLEL FLOW HEAT EXCHANGER

Lesson 2.2 PLATE TYPE HEAT EXCHANGER

Lesson 2.2 SPIRAL TUBE HEAT EXCHANGER

Lesson 2.2 TWO PASS FLOATING HEAD CONDENSER

• COOLAR :-The equipment used for removal of sensible heat is called as cooler.

• CONDENSER :- The equipment used for condensing vapour mixture is called as condenser.

• CHILLER :- For decreasing the temp. of process fluid below atm. Temp. the equip. used called as chiller. In this equipment cooling media used as refrigerant.

• EXCHANGER :-The equipment used for exchanging heat between two fluids is called as exchanger

cont..

Lesson 2.2 H.T. EQUIPMENT TYPES

• HEATER:-The equip. used for supplying sensible heat to the process fluid is called as heater.

• REBOILER :-In this type of heat transfer equipment process fluid is heated by recirculation is called as Reboiler.

• VAPORIZER :-In this equipment fluid is heated & converted in to vapour is called as Vaporizer.

• WEST HEAT BOILER (WHB) :-The equip. used west heat to produce steam is called as WHB.

Cont..

• BOILER:-The equip. in which coal, LDO or gas is used to generate steam is called as boiler.

• EVAPORATOR :-The equip. used to increase the concentration of liquid by evaporating the water is called as evaporator.

• SUPER HEATER :-The equip. used to super heat the steam with the help of hot gas is called as super heater.

• PREHEATER :-The equip. used to preheat the liquid before processing the fluid is called as preheater.

PURPOSE OF HEATING & COOLING

•Drying of solid•Heat recovery from process heat•Prevention of material from plastising & lumping. •Cooling required for safety precaution.

HEATING & COOLING TAKEN PLACE IN HEAT EXCHANGERHEAT EXCHANGER BY INDIRECT METHOD.

WHILE IN HEAT TRANSFER EQUIPMENTHEAT TRANSFER EQUIPMENTINDIRECT OR DIRECT METHOD SHOULD BE USED

Lesson 2.3 REBOILER• In distillation or evaporation operation the equipment used

for boiling liquid is called as Reboiler. Reboiler boils the liquid at low pressure that’s why the boiling pt. Of component is high. The vapor formed from reboiler is directly flashed in distillation column.

THERE ARE FIVE TYPES OF REBOILERS.

1. JACKETED KETTLE TYPE REBOILER2. INTERNAL REBOILER3. KETTLE TYPE REBOILER4. THERMO SYPHONE REBOILER ( CALANDRIA

REBOLER BOTTOM END INPUT)5. THERMO SYPHONE REBBOILER (DIRECT LIQ.)

Lesson 2.3 REBOILERTHERE ARE FIVE TYPES

OF REBOILERS.1. JACKETED KETTLE

TYPE REBOILER2. INTERNAL REBOILER3.KETTLE TYPE REBOILER4.THERMO SYPHONE

REBOILER ( CALANDRIA REBOLER BOTTOM END INPUT)

5.THERMO SYPHONE REBBOILER (DIRECT LIQ.)

• BOILER IS THE CLOSED VESSEL IN WHICH FUELS IS BURN & STEAM IS PRODUCE AT REQUIRED TEMPERATURE & PRESSURE.

• THE MAIN FUNCTION OF BOILER IS GENERATION OF STEAM.

• THERMODYNAMICALLY STEAM GENERATION IS CARRIED OUT AT CONSTANT PRESSURE.

• WHEN 1 Kg OF WATER IS HEATED SO BOILING POINT COMES IF HEATING IS CONTINUALLY, TEMP. NOT INCREASE BUT IF PRESSURE IS CONSTANT STEAM IS PRODUCE. AT THIS TIME HEAT IS USED WHICH IS CALLED AS LATENT HEAT

Lesson 2.3 INTRODUCTION OF BOILER

• THERE ARE MAINLY THREE TYPES OF STEAM 1.WET STEAM :- If steam is mixed with water is called as wet steam.

• 2. DRY OR SATURATED STEAM :- If wet steam is heated up to last molecule’s of water the steam produced is called as dry steam.

• 3. SUPER HEATED STEAM :- If dry steam is heated more & more the Temperature of steam is increase it is called as super heated steam. Super heated steam is called as very hot gas also like that ideal gas.

Lesson 2.3.1 TYPES OF STEAM

• ELECTRIC POWER GENERATION.• IN STEAM ENGINE• IN CRANE• IN CENTRAL HEATING SYSTEM.• IN PROCESS INDUSTRIES FOR HEATING PURPOSE• FOR COOKING• STURILIZATION • VESSEL WASHING

Lesson 2.3.2 USE OF STEAM

There are many types of boilers.1. According to tube content. (A) fire tube boiler

(B) water tube boiler 2. Position of furnace (A) externally fired boiler

(B) internally fired boiler3. Water circulation (A) natural circulation boiler

(B) forced circulation boiler4. According to uses. (A) stationary boiler

(B) mobile boiler5. Working pressure. (A) low pressure

(B) medium pressure(C) high pressure

Lesson 2.3.3 CLASSIFICATION OF BOILER

6. According to axis of drum. (A) Horizontal boiler(B) Vertical boiler

7. According to curvature of tube. (A) Straight tube boiler(B) Bend tube boiler

8. According to hot source.(A) Coal fired boiler (D) Electrically heated boiler (B) Oil fired boiler (E) Nuclear boiler(C) Gas fired boiler (F) Waste heat boiler

9. According to draught. (A) Natural draught (B) Artificial draught

10. According to number of tubes. (A) Mono tube boiler (B) Multi tube boiler

LESSON NO. 2.3.3 COCHARAN BOILER

Lesson 2.3.3 BABCOCK & WILCOX BOILER

Lesson 2.4 MAINTENANCE OF H.T. EQUIPMENT

GENERAL MAINTENANCE WORK OF HEAT TRANSFER EQUIPMENTS ARE,

- Leakage from tube sheet & equipment body.- Scale formation in tubes & in shell.- Corrosion in whole body.- Expansion probleum.-

Lesson 2.5 FURNACE AND KILN• For heat generation solid, liquid or gas are burned in

closed container is called furnace.• Three types of furnace are there:1. SOLID FUEL FURNACE2. LIQUID FUEL FURNACE 3. GAS FUEL FURNACEKILN : It is one type of furnace in which any types of fuel

is burn. MAINLY TWO TYPES OF KILN:1. SHAFT KILN2. ROTORY KILN :(1) DIRECT FIRED (2) INDIRECT

FIRED