The goal of blowing is to clean the circuits of steam, water and oil, to prevent damage to the turbine and a wrong working of the solar energy plant.
The process consists in injecting steam at high temperature, velocity and pressure, intermittently, alternating expansion and contraction of the pipe, in order to dislodge the micro-particles of rust, calamine, paint, etc., which are located inside the pipe, in the steam / water part, and blowing air at low pressure in the oil part, to remove dirt and dry the circuit to a dew point determined.
It can be done in two different ways: giving off steam to the atmosphere at the end of the circuit or recovering it, when the water needed to generate steam is scarce, as happens with the blown of BeniMathar (Moroco).
This is a unique and highly technical process, where many parameters must be controlled.To do this, it is considered the mass and energy balances given by the client, the piping configuration and the equipment to be blown, and it is made an hydraulic model of the plant to know the viability of the process.
Then, the temporary pipeline is designed, according to ASME standards and in accordance to the standards of construction of the plant; an analysis of stress on the pipeline is done, which includes an analysis of withstanding, and the necessary documents are prepared, as technical reports or security plans.
The result is a detailed working procedure, which guarantees the cleaning and the drying of the HTF pipelines of the solar field, the loops of the solar field and the power island.
BGRI began blown activity in 2009, with the work in tower technology plant of Abengoa, PS 20, and achieved a milestone by executing the pre-operational cleaning of the 800 MW combined cycle which Enel built in Algecirasin 2008.Later, some works for TeymaAbener were developed, and it is currently preparing the ones for the solar thermal plant of Shams, at Abu Dhabi.