Acme Automatic Scraper Strainers

Overview of Technical Advantages and Product Design

G.S. Presser, P. Eng. November 2004

Advantages of Scraper Strainers

Can automatically remove large and small particles,

unlike backwash strainers.

Solids accumulate at the bottom of the vessel and are

blown down using dirty water, in place of backwash from

the clean side of the screen.

Scraper mechanism eliminates stapling and blinding.

Special designs effective for low intake pressure or

suction-side applications.

Flexible control systems to reduce liquid loss during solids

blowdown.

View of Scraping Mechanism

All SS316L or Monel construction regardless of vessel material.

Durable wedgewire screen prevents blockage.

Spring-loaded blade and brush maintain contact with screen as they wear.

Large open area between scraper supports to allow large solids to fall directly to collection area.

Problems With Backwash Strainers – Typical Designs

Large solids and bio-fouling cannot be removed by these designs.

Membrane filter pre-screening

Our smallest strainer-a 6” vessel good for connections up to 3”, 200 USGPM.

Optional bypass skid to maintain flow during servicing.

Compact design, easy to install

Available in CS, SS304/316, Alloy 20, Monel and Titanium.

Filtration down to 75 micron.

Skid increases the efficiency and reduces maintenance requirements of downstream equipment.

Raw seawater intake for desalination plant

Three 24” inlet/outlet strainers in SS316L for the Dunore Point water treatment plant in Ireland.

5mm filtration, using a collector system bracketed by gate valves for solids removal.

Acme’s largest SS strainers to date.

Gate valve isolation system

The Dunore Point pumps could

not tolerate a loss of flow or

pressure upstream;

The strainer blowdown had to

be isolated from the regular

flow;

Two 8” SS gate valves were

used to bracket a collector

section;

Water was injected to assist in

dumping the solids into a

trough for disposal.

Low pressure/suction side design

4” CS strainer designed for installation in a hazardous area for sludge filtration;

Low pressure in system meant that line pressure was insufficient for adequate solids blowdown;

Gate valve closes to isolate collector while jets add pressurized water to assist blowdown;

Uninterrupted flow.

Application: River Water Intake

18” connections, 11,000 GPM

off the Columbia river.

400 micron filtration for a

smelting furnace cooling water

application.

In operation since 1996 with

very little downtime.

Complete package with

controls and blowdown valve.

Wastewater pre-treatment

Our smallest strainer-a 6” vessel

good for connections up to 3”.

Used to remove solids in a multi-

stage filtration project in NYC.

Compact design, easy to install

Available in CS, SS304/316,

Alloy 20 and Titanium.

Filtration down to 75 micron.

Application: Saltwater Intake

10” In-line strainer fabricated in CS

with special coal tar epoxy coating.

Used for saltwater intake at the Tynes

Bay Bermuda water treatment facility.

Special Ashcroft differential pressure

switch with diaphragm seals for

islolation.

Separate control panel.

Jacketed strainers for viscous fluids

6” SS304L steam jacketed strainers for a CSX terminal.

Jacket designed to keep the asphalt fluid during the transfer process.

Solids removed manually using a hand valve at the end of a batch.

“U” stamp vessel.

Pump Seal Water Protection

3” SS316L 100 micron filter used as a first pass in a multi-stage seal water filtration skid at a power plant.

Strainer output goes to two cyclone units that provide filtration down to 5 micron.

Note the booster pumps to increase velocity for the 5 micron filters.

Sewage/stormwater filtration

Strainer designed to automatically remove up to 6” stones from a waste slurry;

Tall collector bracketed by gate valves connects to flange on bottom of vessel;

Collector fills with debris, top gate valve closes and collector is dewatered prior to dump;

Ideal for applications where a settling tank is impractical.

Where Can You Use an Automatic Strainer?

River and lake water intakes with manual basket strainers

or no strainers at all.

Old duplex strainers in hard to reach areas, or that plug up

frequently.

Replace older automatic strainers manufactured by Zurn,

RP Adams, Kinney, Tate Andale, Hayward and Spirax

Sarco (scraper unit).

Low pressure situations like gravity flow from tanks.

Intakes with heavy solids loading, large solids and viscous

fluids.

Things to Remember About Acme

A custom manufacturer of strainers, process

heating equipment and gas detection systems.

In-house capabilities for mechanical, electrical and

electronic systems and controls.

Equipment made for your customer’s specific

requirements at a standard product price.

Small, responsive company with accessible and

accountable management.