Real-time Condenser Cleaning System

U K Mullick is passionate about engineering innovations. So far he as an author has featured on two occasions on innovative products in our past issues. Here he provides information on condenser cleaning.

Various types and sizes of Condensers are widely being used in different types of Cement, Power and Chemical plant in India. All such Condensers, as a matter of conventional practice, are required to be cleaned at different time intervals depending on various input factors.

At present, mainly the following types of cleaning processes are used in cleaning such Condensers depending on various factors: (i) Ball Cleaning System, (ii) High Pressure Abrasive cleaning, (iii) Chemical Cleaning System, (iv) Ultrasonic De-scaling System.

Each of the above system requires shut down of the condenser or in other words, the Plant for 10 to 14 days, depending on the size and capacity of the condenser. Such shut down directly affects productivity and the efficiency of the complete Plant. Again, in case the condenser tube calls for any replacement due to any reason, the shutdown period may be even more than two weeks.

In the recent past, after continuous and relentless study and research, a new innovative way has been found out. This new system is not like the above conventional system. The Condenser cleaning is done by online Real-time basis. This system is termed as Real-time Condenser Cleaning System or in short RCCS.

The most important factor for which it has been found to be more popular in Plant abroad is that it does not require any shut down or stoppage of plant or Condenser for regular maintenance or cleaning. It is a real time online continuous cleaning process wherein any suspended particle carried by liquid water flowing through the Condenser tubes do not get any chance to get settled inside the tubes. This activity prevents any deposition of any suspended particle and thereby helps not form any layer inside the tube surface that may call for descaling later on. This system helps to improve the Heat Transfer of the Condenser considerably which may enhance the Heat transfer efficiency of the Heat Exchanger.

General Introduction of RCCS

The real-time online condenser cleaning and enhanced heat transfer system (RCCS) of condensers developed, has been successfully implemented in the Cement, thermal power plant, alumina, central air conditioner Plant, petroleum, metallurgical, paper making, sugar refinery, pharmaceutical and salt making industries.

It can greatly improve the heat exchanger efficiency more than 30% and make the heat transfer equipment to maintain best working state for long time.

RCCS

Principle of Operation

The Spiral (as shown above) is having at its one end Steel Adopter Housing with Ceramic Bearing while the other end is loose. The length of the Spiral is decided by the length of each tube of the condenser . The spiral is made of specially designed Multi-composite Polymer which withstands a wide range of temperature. This Spirals with its attachment is fixed at one end of each Condenser Tube.

Condenser Tube

When RCCS is installed into heat-exchanger tube, the circulating water affects the Spiral which initiates its continuous rotation at a speed of 300??,800 rpm. The rotation of Spirals is being maintained without any supplementary power supply. The circulating water flow gives the power to the Spirals to rotate. These rotating Spirals turn the laminar flow into the turbulent flow. Disturbances of stagnant boundary layers on sustained basis suppress the mechanism of fouling formation and prevent from deposit formation inside the tube walls. In opposition to traditional technologies of passive fouling cleaning, RCCS provides active in-service fouling prevention on continuous basis. Since all chances of formation of deposit inside the tube is fully prevented, the Condenser does not require any cleaning by taking shut down of the plant. The Spirals are made from some special quality of Plastic like material whose life is about 8 to 10 years.

Service Conditions

RCCS is suitable for straight tube and shell heat exchangers, condensers, evaporators used in energy, petroleum, chemical, metal, salt, refrigeration and other industries, including applications such as reactors, air pre-heating systems, etc. The system can be adapted to operational conditions of 20% sulfuric acid, 20% hydrochloric acid and 20% nitric acid solutions, solutions with up to 100% sodium hydroxide (caustic acid) and ammonia content. Operating temperature of the Spirals and its accessories is from ??00 ?C to +220 ?C.

Functions and Benefits

RCCS uniqueness relies on simultaneous implementation of the two major functions:

enhanced heat transfer coefficient and real-time cleaning of heat-exchanger equipment during the actually long-life operation. Benefits are:

(i) Heat transfer efficiency increases more than 30%

(ii) No additional equipment required for Routine shutdown and cleaning activities

(iii) Easy to install the Spirals and its accessories (RCCS)

(iv) No separate power supply is required to rotate the Spirals

(v) No spare-parts required and hence no additional operational cost.

(vi) No effect on environmental safety

(vii) Improved heat transfer helps to save power on sustained basis.

Enhancement of Heat Transfer Indicators

RCCS has an obvious effect on enhancing flow disturbance. Steady laminar flow is turned into turbulent flow, which results in disturbance of the stagnant boundary layer, maintenance of even temperature distribution within the tubes and significant increase of heat transfer coefficient.

Such effect is proved with both theoretical calculation and operational characteristics of the heat-exchanger equipment currently being operated.

Heat Transfer Indicators

heat-exchanger equipment

A 20?0.6 austenic steel tube has been used for tests. Considerable heat exchange improvement has been proved under low and high flow rate values and Reynolds number values.

RCCS technical advantages are explained by its principle of function. If compared with traditional methods of cleaning, such as ball cleaning systems and ultrasonic de-scaling systems, RCCS improves heat transfer co-efficient considerably and prolongs heat exchanger equipment service life.

Author: Authored by: U K Mullick, who is a Mechanical Engr, worked at L& T; WIRTGEN INDIA,Tata Motors, AMW MOTORS (ESSAR Group), Mahindra & Mahindra. A total of 40 years of experience in Sales, Marketing and Business Development.