Prepared by :- MAULIK RATHOD

NISARG THAKKER GAURAV THAKKER BHARGAV BAROT

TITLE OF PROBLEM/PROJECT.TITLE OF PROBLEM/PROJECT.

AN APPROACH TO OVERCOME LEAKAGE PROBLEM IN TUBE TO TUBE SHEET JOINTS OF HEAT EXCHANGER.

•CLASSIFICATION OF HEAT EXCHANGER.

The classification of heat exchanger can be done as according to •TRANSFER PROCCESS,

•NUMBER OF FLUIDS,

•CONSTRUCTION and

•HEAT TRANFSER MECHANISM.

Types of heat exchangerTypes of heat exchanger

There are mainly two types of heat exchangers

1.Recuperative Heat Exchangers

2. Regenerator Type Of Heat Exchangers 

Recuperative Heat Exchangers :-

In such type of heat exchanger flowing fluids exchanging heat are on either side of in the from of pipes or tubes.This heat exchangers used when two fluids can’t be allowed to mix fluids.Examples:-•Automobile radiators,•Oil coolers,•Intercoolers,•Economizers,•Evaporators of an ice plants

In a Regenerators type of heat exchangers the hot & cold fluids pass alternately through space containing solid particles or matrix, these particles providing alternately a sink & a source for heat flow.

Examples:-•I.C. Engines & Gas Turbines,•Glass Melting Furnace,•Air Heaters of blast furnaces.

Regenerative Heat Exchanger

MATERIAL OF CONSTRUCTIONMATERIAL OF CONSTRUCTION

Problem & Its Losses to Heat Exchanger.

•It is observed leakages in heat exchanger during its operation. The main leakage problem is found in the tube to tube sheet joints.•In this project, Efforts are made to overcome this leakage problem by applying novel methodology.•The Recuperative type heat exchangers are made by using tubes & tube sheets, Problem occurs in tube to tube sheet joints are of leakage of fluid in between joints.To fine out leakage in heat exchanger haydrotest to be done to fine out is there any leakage or not.•Tube to tube sheet joint has the single objective of sealing against inter leakage between tube side and shell side fluids. The type of tube-to-tubesheet joint to be employed is thus largely dictated by the anticipated difficulty in providing a reliable seal.

Factors which influence the evaluation of the difficulty of providing a reliable seal at the tube-to-tube sheet joint include the following

•Leak characteristics of either the tube side or shell side fluids. •Differential pressure across the tube-to-tube sheet joint.•Operating temperature to which the tube-to-tube sheet joint will be subjected.

•Relative hazard of inter leakage between the tube side and shell side fluids.

•Frequency and magnitude of cyclic service to which the tube-to-tubes sheet joint will be subjected.•Corrosion characteristics and erosive tendency of the tube side fluid.•The Metallurgy of the tube and tube sheets.•Industry preference such as utility, refinery, chemical, petrochemical etc.

 VARIOUS TYPES OF TUBE TO TUBE-SHEET JOINTS

 There are four types of tube-to-tube sheet joints:

  Expanded Joint Expanded & Seal Welded Joint Strength Welded Joint Strength Welded and Lightly Expanded Joints

EXPANDED JOINTEXPANDED JOINT

1). Expanded Joint

Where in the grooves of the tubes are expanded in the holes of the tube-sheet by heating the tube.

Why expansion? 

The tube expansion technique is used, Because the welding can’t be done to the tube to tube sheet joint inside tube sheet. So remaining gap between tube and tube sheet may be cause of corrosion. Also there were some gap between tube and tube sheet hole so that to remove that gap we have to do tube expansion.

i). Expanded Joint without grooves

  The strength is poor

The leak resistance is poor

Tube replacement is very easy

Application is limited (i.e. low pressure water or air)

There are two types of Expanded Joint :

I . Expanded Joint without grooves ii . Expanded Joint with grooves

ii). Expanded Joint with grooves

  Strength is limited. (can be improved by explosive expansion.)

Leak resistance is limited. (can be improved by explosive expansion.)

Tube replacement is easy.

Applicable for low stresses and low consequences of leakage.

Result AnalysisResult Analysis In the results analysis we have such type of solutions,•Vibration occurs due to unbalanced force of flow of fluid, which are produce more vibration than required ,To stop such situation keeps flow of fluid constant as possible.

•To carry over the Mechanical Stress use thick Diameter of tube, which required less expansion process (Rolling Of tubes). •Less expansion of tube decrees overall cost of Heat Exchanger.

• Erosion ,which removes metal rapidly because of friction which produce erosion as well as corrosion Use Stainless Steel, Aluminum, Carbon Steel Tubes there which are easily available & less effective to chemistry of fluid.

•This all operation can improve the effectiveness of Heat exchanger.

Improvement in outcomeImprovement in outcome