Research of the performance of pulse electrohydrodynamics in blockage removal

Abstract

In line with contemporary trends and seeking to develop new methods and technologies, a new, original technology was explored and designed based on a non-conventional process of electrical pulse discharge in a water chamber, referred to as 'Pulse Electrohydrodynamic Technology' (PELHYDT). The application of the PELHYDT in sewer blockage removal is presented in this paper. Existing machinery can remove two blockages of gully pot connections per hour. Three blockages of pipe conduits are generally removed during an 8-h working day. Applying PELHYDT technology, which allows for high rates of removal of mechanical obstructions, it is possible to achieve operating fluid pressures in the order of 10(3)-10(4) bars, a velocity of 100 m/s, a deformation acceleration of the model material structure of 10(6)-10(7) m/s2, and high-frequency hydraulic shock waves with a frequency of 10(3)-10(4) Hz. The applicability of this efficient technology in sewer blockage removal was proven under laboratory conditions at operating fluid pressures from 50 to 160 bars, which are standard for sewer maintenance. Water velocities generally achieved in sewers using existing flushing technologies range between 1 and 3 m/s and usually do not exceed 9 m/s. PELHYDT creates waves whose velocity is at least 100 m/s, and is therefore about ten times more efficient than existing technologies. PELHYDT generates an electrohydrodynamic wave very quickly, virtually in the form of an explosion. It was proven under laboratory conditions that the application of this technology for blockage removal in practice will not result in any sewer damage.

Project management using the developed AHP–VIKOR method with the fuzzy approach

“…Alternatives are evaluated based on criteria that are often used in such analyses (Jevtic et al 2011;Milojkovic et al 2016aMilojkovic et al , 2016bMilojkovic & Romanović2018;Milojkovic 2019). There are six criteria in total.…”

“…The criteria and the alternatives are described in the previous section, and these were chosen. If sewerage facilities are well designed and constructed, virtually the only maintenance required is the occasional cleaning of conduits (Jevtic et al 2011). Evaluation of alternatives is carried out according to the above criteria functions, which can be expressed in the form of quantitative economic indicators, technical indicators, or quantitative and qualitative indicators (Milojkovic et al 2016a).…”