ReFlow(patent pending), an original idea developed by Renzo Chirulli and Manuel García Román (University of La Laguna, Tenerife – Spain), was selected to be between the three finalists of IWATER Idea Awards 2016, held in Barcelona, Spain on 15-17 November 2016.
ReFlow – Flow Enhancement, Rehabilitation and Cabling is a modular mold that allows to reshape existing sewer conduits, migrating from a traditional circular or egg-shaped cross section to an algebraic curve of degree higher than two (i.e. Bernoulli’s lemniscate or Huygens lemniscate). The resulting reshaped cross section significantly increments fluid velocity at the lowest flow rates. Low flow rates in sewage pipes cause sedimentation of solids and other problems derived from the lack of water aeration and generation of hydrogen sulfide, namely metal corrosion and concrete attack by sulfate. The new reshaped pipe invert is obtained by assembling several molds, manhole to manhole, in a continue string, before carrying out a trenchless relining operation (i.e. Cured In Place Pipe). The new liner, installed by a trenchless method, takes the shape resulting from the combination of the existing pipe and the ReFlow mold, as shown below.
ReFlow does not enhance merely hydraulic performances, it allows to construct several secondary conduits, obtained in the body of the mold string. The new conduits result to be parallel to the pipe axis and perfectly protected against the most common attacks (fluid dragging, mice, etc.). These secondary conduits can be used to install fiber optic cables, transforming the sewer main in a telecommunication infrastructure.
ReFlow is a simple and smart way to solve common problems due to low fluid velocity at low flow rates, such as sedimentation and hydrogen sulfide and for cabling a sewer main before rehabilitate it with the most popular trenchless methods.
ReFlow is a patent pending product.
We are looking for a strong industrial/commercial partner.
What I did: I made the detailed design and work supervision of the installation, by hybrid pipe jacking/down-the-hole concentric air hammer technique, of three DN300 (12”) steel casings and the installation, by slip-lining, inside the 12″ steel casings, of three HDPE DN280 (11″) pipes, for the crossing of a rocky hill – Length of each crossing: 106,0 meters. The HDPE DN280 pipes, installed inside the 12″ steel casings, were used by SIEMENS to lay hi-tension electrical cables. A MITSUBISHI ULTRA MAXBIT 12″ were used to perform the boreholes.
HYBRID PIPE JACKING/DTH CONCENTRIC AIR POWERED HAMMER TECHNIQUE
What I did: I made the detailed design of the replacement by dynamic pipe bursting of a DN600 (24″) sewer concrete pipe with a DN800 (32″) HDPE pipe; I coordinated all the geological/geotechnical preliminary survey and I also made the detailed design of the bursting-expanding head, tailored shaped to work with a Tracto Technik TAURUS rammer (24″). The expander has an outside diameter of 1000 mm. The soil was sand with coarse to very coarse gravel.
LARGE DIAMETER DYNAMIC PIPE BURSTING FOR SEWER REPLACEMENT
What I did: I made the detailed design of the installation of pressure and gravity sewer pipes by directional drilling; I carried on the training of the technical personnel (engineers, supervisors and operators). I developed a dedicated and complete HDD pit launched installation system for the connection of houses to the sewer mains. I also wrote two technical standards: the first for preliminary underground mapping and the second for the construction of house connections by using pit launched HDD machines.
What I did: I made the detailed design of the installation of underground pipes, ranging from 100 mm (4″) to 500 mm (20″), by Horizontal Directional Drilling, in hard to very hard rock; HDD at sharp radius in rock and application of HDD to pre-tunneling compensation grouting and directional underground injections for insulation and treatment.
HDD IN CHALLENGING ROCK CONDITIONS AND COMPENSATION GROUTING BY HDD
What I did: I made the detailed design and supervision of the installation by microtunneling and HDD, in very hard and abrasive quartzite-diorite rock, of a DN700 mm (28″) cast iron water pressure pipe – the work was split in two section, each one 80 m (265 ft) long. The borehole diameter was 800 mm (32″). A very challenging job for the extreme hardness and abrasivity of the rock. The water pressure pipe is part of a mini hydro-power plant in the Alps (Italy).
INSTALLATION IN VERY HARD AND ABRASIVE ROCK OF A DN700 CAST IRON WATER PRESSURE PIPE
What I did: I made the detailed design of the rehabilitation, by thermal and UV CIPP, of DN1200 and DN1000 (48 and 40 in) sewer mains for a total length of 220m, at the Petrochemical Plant of Porto Marghera, Italy; detailed design of the rehabilitation, by thermal CIPP, of DN1200 (48″) sewer mains for a total length of 1.250 m, in the cities of Scafati, Pompei e Sant’Antonio Abate, Italy.
DESIGN OF THE REHABILITATION OF LARGE DIAMETER SEWER MAINS BY CIPP
What I did: I made the detailed design and project management of the rehabilitation, by UV-CIPP, of air-conditioning pipes DN350, laid under runways, at the international airport of Fiumicino Leonardo da Vinci (Rome, Italy).
UV-CIPP AT THE INTERNATIONAL AIRPORT OF ROME FIUMICINO