Anotec 6-Anode Heavy-Duty HSCI Sled for Use in Seawater

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Anotec 6-Anode Heavy-Duty HSCI
Sled for Use in Seawater

Six Heavy High Silicon Cast Iron Anodes mounted on a corrosion
resistant frame for discharges from 20 to 40 Amps.

Description

Six Heavy High Silicon Cast Iron (HSCI) Anodes (each 315 lb / 140 kg) are securely mounted on a corrosion resistant frame (sled). The sled weighs approximately 2000 kg (4410 lb), depending upon the size and length of shore lead cable. The footprint is nominally 2.1 m x 2.0 m, height 0.6 m. (7 ft x 6.5 ft x 2 ft). Please also see Anotec's 4-Anode Compact HSCI Sled.

Sled Life vs Current

Anodes are spaced for uniform current discharge and consumption. Although high silicon cast iron (HSCI) in sea water can withstand current discharge amperages exceeding 5 A / sq ft (55 A / sq m), the following factors should be considered:

a) Environmental Regulations may restrict sled discharge current to lower values. (i.e., less than 1 volt / meter electric field strength in natural waters).

(b) Sled Life will depend upon the weight of anodes, the amperage, their consumption rate and utilization efficiency. For purposes of example only, the following values have been assumed to predict Life Expectancy, according to Anode Model (Size) and Sled Current Discharge (Amps). Please refer to the above figure, which is based on:

Consumption Rate Range: 0.75 lb / A-Yr (0.34 kg / A-yr) to 1.5 lb / Amp-Year (0.68 kg / Amp-Year).

Utilization Efficiency: 85% (percentage of anode mass that can be reasonably expected to perform CP).

Anode Mass: 6 x 4884 SZ Anodes (1890 lb = 857 kg).

Based on the above assumptions, the figure charts 6-Anode Sled Life in relation to Sled Discharge Amperage for the Consumption Rate range.

Note 1: In 1995, Anotec conducted a 120-day test of anodes submersed in saltwater / mud at the GVRD Seymour-Burrard CP System, operating at 41 Amps / m² (3.8 Amps / ft²). Consumption Rate range: 360 to 490 grams / Amp-Year.

Construction

Each Type 4884 XX anode has a single #8 Halar / Kynar HMWPE cable lead connected to a Shore Based Rectifier (not included) by means of two parallel insulated cables (usually, but not limited to #6, #4 or #2 HMWPE 600V) protected by heavy wall EPDM rubber hose. Length permitting, dual cables of #2 or smaller may be protected by a single hose.

Each anode lead exits from the side of the anode 400 mm (16") from the center connection. The lead wire is protected by a sleeve of rubber hose at the hole in the anode wall. The interior of the anode is encapsulated with epoxy for 460 mm (18"), covering the anode-lead. Each anode has spare lead-wire coiled slack for onsled repair / replacement of the shore connections.

The on-sled junction between anode leads and shore leads utilizes high strength ground connectors (copper), sealed and protected by Epoxy (Polyspec 757 or DuoChem 8113) mixed with sand (Anotec WI 4.9.4). The epoxy mass is encased in a PVC tube. The mixture of epoxy and sand has been carefully developed and tested by Anotec to insure that the epoxy-sand mass cures gradually and evenly for optimum sealing quality. The shore lead cables and protection hose(s) are securely encased in concrete in the Sled Frame before terminating in the on-sled junction.

The Sled frame consists of two, 12" (300 mm) PVC Class 63 pipes 78" (2000 mm) long filled with reinforced concrete. The pipes are connected together by three, 4" (100 mm) fiberglass tubes filled with 35 MPa reinforced concrete.

The Sled frame includes 4 lifting eyes and 12 anode clamps manufactured from 5/8NC steel U-bolts powder coated with epoxy, cover protected by a heat shrink sleeve and a 1" EPDM rubber hose jacket. The U-bolts are cast into concrete and exposed threads are epoxy coated. Heavy-duty, all-plastic tie-wraps are cast into the pipes and tubes to secure on-sled cables and the junction enclosure behind and shielded by structural members.

Sleds have been operating since 1993. More than 220 sleds are in service today, primarily on the British Columbia coast. Most of these protect B.C. Ferry Corporation wharf structures in turbulent and silting conditions.

A Name Plate secured into concrete lists Anotec and the Sled Serial Number and Date of Manufacture. Customer Project Information is optional. Each sled is manufactured, inspected and tested in accordance with Anotec's ISO 9001 Quality Program.