by Atul Bansal, Chief Operating Officer, Technical Drying Services
The power plants and oil refineries carry out intricate operations where blasting, painting, and coating are integral parts of the process. Considering that even the slightest trace of moisture can sabotage the efficiency of the processes, exercising effective climate control becomes a prerequisite for operations conducted inside tanks, ammunition, gunpowder, explosives, columns, reactors, coke drums, vessels, pipelines, bullets, and more.
The presence of high humidity is responsible for disrupting surface preparation and coating procedures. Elaborating on the same, blasting is the initial step that enables painting and coating processes. In case, the blasted surface is exposed to humid conditions prior to painting, it culminates in condensation formation that compromises the entire blasting process. Following this, performing painting on a condensed surface gives rise to blistering and delamination issues. Along similar lines, it has been observed that 60–80% of premature coating failures occur due to improper surface preparation, which significantly reduces the life of the coating system. Therefore, ensuring proper surface preparation is crucial for ascertaining thorough adhesion of coating to the substrate, thereby, boding well for driving efficient coating and painting outcomes.
Additionally, the repercussions of improper coating transcend the issue of damaged surfaces. It can cause the contamination and dilution of highly vulnerable materials, such as petrochemicals and chemical gases stored in tanks. As a result, implementing stringent environmental control measures becomes more important than ever for the effective completion of the blasting and coating processes. Failing to do so increases the risk to coating life, where it becomes highly susceptible to peeling when applied to a cold metal surface.
Things get further complicated during monsoon season, when high humidity levels frequently delay or halt the coating process. Moreover, the probability of condensation due to cold nights compounds the problem, contributing to corrosion, commonly known as rust bloom or flash rust. All the factors together impede the timely completion of the project, ultimately affecting plant productivity.
To address the problem, employing desiccant dehumidification solutions plays a pivotal role in facilitating round-the-year blasting, painting, and coating, irrespective of the weather conditions outside. This significantly comes to aid in mitigating the downtime on account of adverse weather conditions, which consequently contributes to minimizing the cost and time for completing the process. The desiccant dehumidification systems empower continuity of process, saving both time and money that otherwise would be lost in impractically conducting blasting and painting separately in a phased manner to avoid condensation.
Curtailing the destructive effects of moisture, dehumidification systems come with the ability to achieve optimal conditions throughout the coating and painting processes. Maintaining stable environmental conditions, the advanced technology stringently meets the industry specifications outlined for temperature, relative humidity, and dew points. Keeping the relative humidity (RH) below 55% while maintaining temperature within the range of 30°C to 35°C, along with a constant dew point differential, the systems provide an ideal solution for achieving precise coating conditions. At the same time, the systems come with the proficiency to maintain a constant dew point differential of -5°C between the air and the surface to be coated and a -12°C dew point difference between the air inside the tank and outside.
The desiccant dehumidifiers come with a wide gamut of advantages, entailing the prevention of surface condensation and reducing instances of inter-coat delamination aimed at enhancing curing properties. At the same time, resorting to desiccant dehumidification solutions comes in handy for exercising 2-4% cost-effectiveness as compared to the total cost incurred in conducting corrosion preventive painting. All in all, by guaranteeing proper surface preparation, moisture removal from the coating system, and averting condensation, it efficiently increases the coating life.
Likewise, the processes being conducted in confined spaces and the systems well equipped with ventilation solutions alleviate the safety concerns of workers. It renders safe and comfortable working conditions within the enclosed spaces, where ventilation systems control temperature during blasting processes, releasing hazardous fumes and inflammable vapors.
Therefore, desiccant dehumidifiers play a crucial role in minimizing the downtime of refineries and power plants. Providing an array of comprehensive solutions for critical operations, it ensures blasting, painting and coating processes throughout the year. Consequently, the technology improves the efficiency and longevity of industrial processes.