The Problem

Depo­si­tion of grit and assort­ed debris is a fre­quent prob­lem in all types of sew­er­age sys­tems. The most com­mon caus­es are large pipe diam­e­ters with small dry weath­er flow rates (aggra­vat­ed by water-sav­ing ini­tia­tives), poor gra­di­ents or sag­ging of pipes due to geo­log­i­cal influ­ences, etc.

Depo­si­tion can result in high­er pol­lu­tant load­ing at stormwa­ter over­flows, inter­mit­tent bio­log­i­cal loads to sewage treat­ment plants, odour prob­lems, a reduc­tion of hydraulic capac­i­ty of the pipes or dam­age to the pipes by sul­phur corrosion.

The Solution 

The Hydro­Guard^® Sew­er Flush is a device for con­tin­u­ous, auto­mat­ic clean­ing of medi­um-sized pipes (DN 600 — 3000).

Use of the Hydro­Guard^® Sew­er Flush reduces the fre­quen­cy of over­flow spills, equal­izes the bio­log­i­cal load pass­ing down to the treat­ment plant, extends the lifes­pan of sew­er pipes, pre­vents odour for­ma­tion and avoids main­te­nance costs asso­ci­at­ed with reg­u­lar tanker flushing.

Con­tin­u­ous flush­ing using the dry weath­er flow pre­vents the build-up of silts and debris. Pipe sec­tions down­stream of the flush­ing device are cleaned by the pow­er­ful flush­ing wave. The upstream sec­tion, used to impound the flush­ing water, is cleaned using the ener­gy pro­duced by the sud­den falling water-lev­el (draw flush).

The Hydro­Guard^® Sew­er Flush can be pro­grammed for a pow­er­ful flush­ing wave for thor­ough clean­ing and small­er waves as pre­ven­ta­tive mea­sures at select­ed times.

Addi­tion­al­ly, the device enables ver­sa­tile and flex­i­ble sew­er man­age­ment. The water is impound­ed and retained in the upstream pipes for a time, to be released lat­er at a pre-deter­mined water lev­el when the flush water vol­ume has been reached. The design takes into account the vol­ume need­ed to effec­tive­ly clean the required length of sew­er at the exist­ing gradient.

Accord­ing to the Ger­man ATV A 128, sta­t­ic pipe vol­ume can be used to enhance required stor­age basin vol­umes. With the Hydro­Guard^® Sew­er Flush addi­tion­al vol­ume from the reten­tion pipework can be acti­vat­ed, reduc­ing the require­ment of sep­a­rate stor­age con­struc­tions. In a “best-case” sce­nario, the con­struc­tion of new over­flow cham­bers or atten­u­a­tion tanks can be avoid­ed com­plete­ly. When dimen­sion­ing stor­age tanks, the A ATV 128 also per­mits the addi­tion­al “over design vol­ume” (to allow for sil­ta­tion) to be reduced, or even dropped com­plete­ly, if silt­ing is avoid­ed by flush­ing with the dry weath­er flow.

Due to its small foot­print and util­i­sa­tion of the exist­ing pipe as stor­age vol­ume for the flush­ing water, the Hydro­Guard^® Sew­er Flush can be retro­fit­ted into exist­ing systems.

The Advantages

• pro­longed, high-ener­gy flush­ing wave
• flush­ing of long sec­tions of pipework with sin­gle flush­ing shields
• flush­ing of long dis-tances, e.g. 6 km, using a series of net­worked Hydro­Guard^® Sew­er Flush units 
• effec­tive down­surge flush up to 2/3 of the impound range
• high flush­ing fre­quen­cy – excel­lent clean­ing results
• vari­able flush­ing volumes
• flush­ing fre­quen­cy freely selectable
• local and/or remote-con­trolled sys­tem 
• oper­a­tion inde­pen­dent of weath­er conditions
• retro­fit pos­si­ble, easy inte­gra­tion into exist­ing pipe systems
• no sole jump
• shield moves upwards com­plete­ly clear of the pipe cross-section
• shield over- and under­flow possible
• no sep­a­rate stor­age cham­ber nec­es­sary for the flush­ing water
• all parts acces­si­ble even dur­ing sew­er operation
• suit­able for pipe sew­er management
• for pipes from DN 600 up to 3000