Case Histories

Brewery Mains Water Supply

Date : MAY 2002
Fluid: dublin mains water
Flowrate: 45 m3./hr 9 165 gpm )
Line size: 3"
Working pressure: 0 – 2 barG
Retention rating: 15 - 20µ
Purpose of filter: protect carbon filters and h2o quality in Day tank.

Requirement: The client wanted an automatic backwashing filter but did not want the expense And bulk of a multimedia or sand filter as they were low on budget and short on Space where they needed to locate it.

Problems to be overcome

They had not got much money to spend and indeed had siphon funds from maintenance budgets to purchase it at the time.
They were short on space in the pump house where they wanted to locate it.

The available pressure was low at only 30 psi with the pump on and the process supply valves open. When the valves were closed they could generate 69 psiG. 30 psi is too low to effectively backwash an RPA filter and they could not afford the additional cost of the additional backwash supply header & valving and supply tank required in an External backwashing unit.

Solution:
We supplied them with an F205IBB 5 station internal backwashing filter in BB ( back to back ) format so as to half the overall length of the unit by locating the filter stations on opposing sides of the inlet & headers. This also means it has to have 2 drain headers.

We supplied with with a pneumatically operated butterfly valve on the outlet header & modified the software so as to close this upon a backwash being triggered By the differential pressure switch thereby allowing the pump to achieve the pressure necessary to backwash them. They also had to fit valves on the drain headers to allow Them to be throttled creating some back pressure and preventing the screens from being blown off.

This is an unusual way of operating an internal backwashing filter but it was the only solution we could offer within budget.