The importance of extracting moisture load from transformers cannot be underestimated thanks to the perils that water might do to the transformer lifecycle. The cellulose which is part of the insulation material, is susceptible to capturing moisture, which is released in the oil. Consequently, the insulation parameters receive a beating.

Popular methods of drying transformer

Transformers are dried through methods like induction heating, hot air drying method, vacuum drying method and gas phase vacuum drying method. As production develops, more advanced drying techniques are employed to remove moisture content from the insulation material.

Transformer drying oven method boasts of several advantages when compared to other moisture removal methods. This method can estimate several samples of moisture at the same time and is a simple procedure which can easily be performed. It can also determine moisture in large sample volumes.

Drying time varies with different sizes and designs of transformers which may use different raw materials. Hence constant vigilance throughout the drying process is essential. While indirect methods for detecting residual moisture during the drying process have uncertainties, dielectric response analysis enjoys growing popularity due to its reliability.

To improve the drying quality of the winding, drying temperature should be kept in control and the vacuum degree of the instrument should be improved. By these measures, the equipment meets the parameters required for drying and provides an excellent drying effect.

Since the transformer has colossal amounts of insulation and water content, ample heat energy is needed for the drying process. At low pressure and low temperature, sufficient heat is provided to enhance the water vapour evaporation process.

The amount of partial pressure difference between the internal and surrounding material of the insulation area is directly proportional to the speed of evaporation, diffusion and migration of water content. After the drying process is completed, an insulation appraisal is conducted so that the drying effect is ensured. 

Hering’s transformer drying oven, with its advanced features improves the drying quality. Century plus expertise of Hering in providing solutions for transformer maintenance and unparalleled German precision in vacuum transformer drying ovens among other products are lauded by clients across the globe.

The transformer’s life cycle is secured in the manufacturing process where it is subjected to the drying process. Hering’s vacuum drying ovens employ state of art technology to minimize drying time and protect the equipment from high internal stresses. Hering drying series comprises a range of product lines that suit varying demands and requirements.

Hering’s vacuum drying oven offers two systems based on the process used. One of them serves less than or equal to 100 MVA hot air drying plant for easy set up and the other is greater than 100 MVA vapour phase drying plant for reduced process duration. These two methods reduce pressure which leads to lower boiling point which makes dissolved water in the transformer's active parts to evaporate.

Hering’s vacuum drying ovens are popular for their robust designs whose operations are comprehensive besides being easy to maintain. Hering assists clients in choosing the right drying process that suits specific applications.

The drying ovens are divided to sub modules which enable swift and easy installation of the plants. These modules, which include heating stations, vacuum pumping stations, kerosine pumping stations and filter stations, are completely piped, wired and pre-tested before being dispatched to customers. Hering also assists clients by training them to set up the plant by themselves.