Proven technology for continuous removal of floating solids and clean water

The Challenge

Set­tling tanks are used in the treat­ment of storm water, com­bined water and waste­water in indus­tri­al as well as com­mu­nal areas. 

They are installed for the pro­tec­tion of envi­ron­ment or for the treat­ment of indus­tri­al efflu­ent. The best known facil­i­ties are oil sep­a­ra­tors. Set­tling tanks are spe­cial­ly designed by expert engi­neers for each appli­ca­tion to achieve opti­mal reten­tion of pol­lu­tion at low flow rates and cal­cu­lat­ed max­i­mum flow rates.

The System

The sep­a­ra­tion of light den­si­ty mate­ri­als basi­cal­ly occurs towards the water sur­face; heav­ier sol­id mat­ter set­tles on the tank floor. The tran­si­tion zones from sed­i­ment to clean water and from clean water to float­ing solids are “mist zones” prone to problems.

Pro­ce­dure 1 
The Hydro­Surf Skim­mer draws the float­ing solids and light den­si­ty mat­ter from the water sur­face for treat­ment. Simul­ta­ne­ous­ly, an Elec­troSlide^®  posi­tioned above the sed­i­ment zone con­ducts  the clean water, depend­ing on tur­bid­i­ty, out of the tank into the receiv­ing waters. After emp­ty­ing, the tank floor is cleaned with the Hydro­Self^® Wave Flush and the pol­lu­tion pumped away for treatment.

Pro­ce­dure 2
The Hydro­Surf Decanter with inte­grat­ed tur­bid­i­ty mea­sure­ment drains away the clean water under the float­ing solids zone. Either through grav­i­ty or by means of a pump, it con­ducts the clean water into the receiv­ing waters. If the sed­i­ment zone is reached when the water lev­el falls, the Hydro­Surf Decanter is closed. A sec­ond motor slide is opened or a pump is used for clean­ing the tank. Float­ing solids and sed­i­ments are washed away to the treat­ment plant by the  Hydro­Self^® Wave Flush.

The Product

The Hydro­Surf Skim­mer and Decanter are man­u­fac­tured com­plete­ly of stain­less steel. They are equipped with a wear-free, smooth-run­ning and water-tight swiv­el joint. One 90° elbow is con­nect­ed to the drainage pipe, the oth­er 90° elbow to the out­let pipe. To enable the Hydro­Surf to work con­tin­u­ous­ly at dif­fer­ent water lev­els, adjustable twin floats (angle, immer­sion depth) are posi­tioned at the inlet. The buoy­an­cy with­in the float can cope with the load­ing con­di­tions under full load. The inlet heads can be man­u­fac­tured on request with inlet grid, scum board or with immer­sion fit­tings and tur­bid­i­ty detec­tor. The Hydro­Surf Skim­mer and Decanter can oper­ate impound heights of approx. 2.50 m to 8.00m. The dis­charge val­ues lie between 5 l/s (DN100) and 200 l/s (DN400).

Stein­hardt GmbH offers design sup­port and, if required, deliv­ery includes com­plete units with elec­tric flow reg­u­la­tor, tur­bid­i­ty detec­tors, tank clean­ing and automation.

Range of Application 

• recov­ery of oper­at­ing materials
• for treat­ment of process water
• before SSO’s into receiv­ing waters
• before soil filters
• before infil­tra­tions