Automatic flushing system for new and existing stormwater tanks

The System

Stormwa­ter tanks in com­bined sew­er­age sys­tems tend to col­lect heavy sed­i­ment deposits on the floor. These sed­i­ments con­sol­i­date dur­ing the next dry peri­od if not removed. Prob­lems of smells and organ­ic load­ing on the receiv­ing water­course can result if these tanks are not prop­er­ly main­tained. It is desir­able to clean stormwa­ter tanks after every use as cost-effec­tive­ly as pos­si­ble.  

The clean­ing of stormwa­ter tanks by means of tip­ping buck­ets is, along with flush­ing with gates, one of the most com­mon meth­ods used for the removal of sed­i­ments from the floor. 

It is an oper­a­tional­ly safe process, which has proved itself in numer­ous appli­ca­tions over decades. Hydro­Self Tip­ping Buck­ets can be installed in new as well as in exist­ing struc­tures for the clean­ing of rec­tan­gu­lar stormwa­ter tanks in open and closed cham­bers and is suit­able for short flush­ing lengths of below 50 m.

The Function

The Hydro­Self^® tip­ping buck­ets con­sist of a spe­cial­ly designed cross-sec­tion­al form which ensures auto­mat­ic release of the flush water with the return of the buck­et to its start posi­tion. When fill­ing is acti­vat­ed, the tip­ping buck­et is filled to a pre­vi­ous­ly set water lev­el. Dur­ing the fill­ing process the cen­tre of grav­i­ty of the tip­ping buck­et shifts so that it turns auto­mat­i­cal­ly and the retained water is emp­tied against the back wall of the stormwa­ter tank. The water flows down and is vec­tored down the tank by the pro­vi­sion of curved bench­ing on the floor of the tank. This con­ver­sion of poten­tial into kinet­ic ener­gy cre­ates a flush­ing wave of high veloc­i­ty and great tur­bu­lence on the lead­ing edge of the wave. It re-mobilis­es the sed­i­ments on the tank floor and trans­ports them to the end of the tank into the receiv­ing sump. After emp­ty­ing, the tip­ping buck­et returns auto­mat­i­cal­ly to its start posi­tion and is ready for oper­a­tion again. If required, the Hydro-Self^® tip­ping buck­et can also be sup­plied with a con­trol for man­u­al or auto­mat­ic operation.

The fill­ing time of the tip­ping buck­et is depen­dent on the inflow and the vol­ume of the tip­ping buck­et. The num­ber of flush­es required is depen­dent on the nature of the deposits. In most cas­es, one flush is suf­fi­cient. Sev­er­al flush­es may be nec­es­sary for espe­cial­ly severe deposits.

The Hydro­Self^® tip­ping buck­et has one or more drain holes so that stormwa­ter can­not accu­mu­late in the buck­et when not needed.

The Advantages

• auto­mat­ic release of flush­ing wave and return to start position
• high clean­ing per­for­mance and low ener­gy costs
• no move­able parts in wastewater
• low-noise tip­ping with smooth slid­ing into the start posi­tion (from any position)
• flex­i­ble vol­ume in any incre­ment between 200 and 2000 l/s
• com­plete con­struc­tion in stain­less steel, in V2A or V4A as required
• water-tight ball bearings
• cor­ro­sion-resis­tant
• easy to install 
• eco­nom­ic and easy mount­ing sys­tem for new struc­tures or already exist­ing tanks 
• low main­te­nance flush­ing sys­tem 
• bend-proof and torque-proof tip­ping trough
• min­i­mal sus­pen­sion strain due to opti­mal torque sequence
• min­imised out­lay in mate­r­i­al, weight and costs due to CAD opti­mised con­struc­tion 
• fill­ing with storm-water, domes­tic water, ground water or potable water