Cleaning & Technical Inspection Heat exchangers

 

Position of Heat Exchangers in Industries:

Heat exchangers are the most numerous and laborious equipment's existing in the oil and gas, petrochemical, refinery, power plant and chemical industries that provides possible exchange and transfer thermal energy between two or more fluids in difference temperature. The fluids may be liquid-liquid, gas-gas and gas-liquid.

Heat exchangers are included: Coolers, heater, Condensers, chillers, boiler, evaporators, economizers and …

Sort and shape designing of heat exchangers are very variety that are divided to the several basic section:

a) Shell and tube: included U type and straight tubes and …

b) Fin tubes

c) Plates

 

Overhaul of NGL and gas compressor plants:                                                        

• Ability cleaning of inside and outside of tubes type of Heat exchangers, and Condensers Air Coolers
• Ability overhaul of heat exchangers include: welding, reamer, local switching tube and expanded them, Blind the connections, replace the gaskets and flanges and ...
• Ability Eddy Current test, hydro test and remote field of tubes and tube heat exchangers, tanks, turbines and ...
• Ability cleaning of reservoirs and towers existing in oil & gas plant
• Ability to Re-tube of heat exchangers, air coolers and condensers
• Ability to build heat exchangers

 

 Cleaning of heat exchanger

 

Existence of fouling in thermal and hydraulic performance is the most main problem designing and operation heat exchangers. Usually, cleaning's cost for any heat exchanger is computed about 40 thousand to 50 thousand dollars in every period of repairing and cleaning of heat exchanger due to formation to the fouling in heat exchangers and Condensers, the level heat exchangers transfer is increased 20% to 200% in the first designing. some of Fouling (Sediment) harms and damages are followed:

 

• Reduction of heat transfer coefficient
• Limiting of External Debbie (flow rate)
• Increasing the number and time of Overhaul
• Increase costs and product price (charges)
• Reduction of production efficiency
• Reduction of systems reliability
• Reduction of equipment useful life time
• Interferes in the process

 

 Damages due to sediment in heat exchangers of industry countries (1992)

Fouling Cost/GNP %	1992 GNP ($ Billion)	Fouling   ($ Million)	Country
0.25	1000	2500	UK
0.25	5670	14,175	USA
0.15	43	64.5	New Zealand
0.25	1950	4875	Germany
0.25	4000	10,000	Japan
0.15	309	463	Australia
0.20	22,510	45,029	Total Industrialized World

 

Cleaning methods of SISACO is followed:

A) De-Scaling modern methods- Hydro mechanical method

These devices use either an electric or air motor to rotate a flexible shaft, which is placed in a plastic casing that transports water to cleaning tools. Cleaning tools range from a variety of brushes to buffing equipment, hones and scrapers. They can clean almost all types of deposits including hard scale. The operator simply feeds the flexible shaft through the tubes to brush and flush out in one operation. This method has made a great difference than other equipment in the market today, hence why it has achieved a US-patent certificate.

 

Advantages:

• Ability destruction of difference sediments because of the specific performance the end tools
• Non-existence effects destruction for tube
• Ability to clean clogged the tubes and avoid of retube
• Ability to clean tubes with a gentle curve
• Reduction of clean significant costs
• Environmental friendly
• Ability to remove sediment up to 100%
• High speed cleaning
• Light and portable equipment
• User friendly
• Less labor needs
• Certificate from the U.S. patent ''USPTO''

 

B) Hydro jetting Method

SISACO processes wide experience of work with this method and offers cleaning for the following Heat Exchangers:

* Shell and heat exchangers: U-shaped, with a floating head

* Spiral heat exchangers

*"Tube in tube" heat exchangers

* Air cooled heat eXchangers

* Waste heat boilers

 

 

Hydrojetting is affected on the following scheme.

A high pressure hose (3) with a hydro jetting nozzle on the top (6) is pushed inside the pipeline (1) with special purpose mechanisms. The water is pumped (5) at the pressure of around 1000 bar, and through the sleeves it reaches the nozzle where the water is blown at high speed from nozzles forming cutting water sprays.

 

 

 

Decoking of spiral exchanger

 

Decoking of U-type heat exchanger shell side

 

C) Chemical Cleaning

Advantages of SISACO chemical treatment against ordinary steaming:

* Less maintenance shut off time (due to reduction of entry time and mechanical cleaning time)

* Lower inflammation risks

* Lower steam and water consumption

* Facilitation of further mechanical cleaning from coke, non-organic and hydrocarbon deposits

* Wide application area -this method can be applied (when washing with water and steaming) both for separate    equipment units and for the whole system

* Fast and safe preparation of equipment for opening

* Saving of plant resource

* Personnel security

 

 

Inspection and Non-Destructive Test

 

Important N.D.T. in Economy and Industry:

• Inform about qualify status, benefit life, defects and damage of piece, material and equipment , …
• Reduction and adjustment of overhaul and inspection time
• Reduction of overhaul and inspection cost

 Pressure test (Hydro test):

Hydro test operation is performed for find leak of shell & plugs and tube in air Coolers.

Tube test and Shell test (Leakage test):

In this method water injection into heat exchanger and raising the pressure can find these leaks, cavities and so on.

Perform to Non-Destruction Test:

One of the main problems that fouling in heat exchangers is always tubes Corrosion & Erosion that knows is necessary in order to aware of heat exchanger situation. The other samples used in Non-magnetic tubes test and magnetic tubes test.

Remote Field Test (RFT)

• Application in magnetic tubes such as: Steel alloys , Stainless Steel ferritic alloys , Monel and …
• Present Corrosion recognized, crack, leakage and reduce of thickness routine in tube length
• Ability record all of tube defects and its showing graphically
• Ability Bend tubes test (that they have radius of curvature up 20 cm)
• Presentation full report of heat exchangers tubes situation and tubes with the most present Corrosion.

Eddy Current Test (ECT)

• Application in Non-magnetic tubes such as: Al – Brass , Cu-Ni Stainless Steel , Admiralty , Inconel and …
• Ability record all of tube defects and its showing graphically
• Present Corrosion recognized, crack, leakages and reduce of thickness routine in length tube
• Ability Bend tubes test (that they have radius of curvature up 15 cm)
• Presentation full report of heat exchangers tubes situation and tubes with the most present Corrosion