FILTRATION SYSTEMS FOR CHLOR-ALKALI AND CHLORATE PLANTS

Edition 3, Dec 2017 YOU ARE IN GOOD HANDS

Established in France in 1997, TECHLINK Associ- ated International Engineers is a leading solu- tions provider in Flow Control, Heat Exchange, Piping safety, Instrumentation for processes handling corrosive, erosive and toxic chemicals. We are committed to serve industries for which quality and reliability are critical for the safety of people and preservation of the environment. With a presence in France, India, Thailand and China, and representations in Korea, Singapore, Malaysia, Indonesia and Pakistan, TECHLINK de- signs solutions for process industries to : ■ Improve availability and performance OTHER PRODUCTS OF ■ Reduce operational costs ■ Enhance safety ■ Save power and recover energy ■ Achieve and/or maintain environmental ■ Regulatory compliance ■ Meet ISO 14000 objectives FOR CHLOR-ALKALI PLANTS ■ Simplify management

► ION-EXCHANGE COLUMNS with Ca/Mg free hard rubber lining and titanium internals.

► GAS SCRUBBER SYSTEMS For removal of chlorine, HCL, sulphur dioxide and other pollutants from stack gas and tank vents. Ejector type, or packed bed type. With or without blower. Self controlled.

► TITANIUM VESSELS AND COMPONENTS

Chlorine cooler, brine filtration vessels, depleted brine tanks, depleted brine pumps and strainers, chlorate piping and tanks.

► NICKEL VESSELS AND COMPONENTS

► ANALYTICAL SYSTEMS, on-line concentration monitoring

► TURN-KEY SYSTEMS Storage systems, cooling systems, mixing systems, filtration systems, scrubbers, delivered as skids

Edition 3, Dec 2017 SINGLE-STEP NANOFILTRATION FOR CALCIUM & MAGNESIUM REMOVAL

In association with technology provider PROFILCO of the Netherlands, TECHLINK builds turn-key, single step brine filtration systems based on Tefflux® nanometric membrane technology and back- pulse membrane cleaning. The systems can, in one step, remove calcium and magnesium from raw brine, and make it ready for ion-exchange beds.

The system eliminates the need for a clarifier and a primary filter. No body feed is required for final filtration.

Salt Weak brine CLASSIC BRINE PREPARATION METHOD

α­cellulose

Caustic soda

Sodium carbonate

Secondary Ion- filter exchange Purified brine resin bed Clarifier

Primary filter S l u d g e-g anthracite filter S l u d g e THREE STEPS e

BRINE PREPARATION WITH ONE-STEP NANO-FILTRATION WITH TEFFLUX® BACK-PULSED MEMBRANES Salt Weak brine

Caustic soda

Sodium carbonate

Tefflux® membranes, Ion- backpulse, nano- exchange Purified brine filtration system resin bed Reactor pit

SINGLE STEP S l u d g e

RECLAIM xxxx m² OF PLANT SPACE !

Edition 3, Dec 2017 HOW DO TEFFLUX® NANO- FILTRATION MEMBRANES WORK?

TEFFLUX® nanometric pPTFE membranes are produced in USA. They are seamless tubes of about 15mm diameter of expanded PTFE. The absence of seams is a strong guarantee against failures of membranes. The tubes are mounted on PP cylinders, and assembled in sets of nine, which more or less replicate the dimensions of a classic candle. For this reason, the Tefflux® nanometric membranes can be retrofitted in existing filter vessels using existing tube sheets. Alternatively, new vessels and tube sheets may be supplied made of titanium.

Single element structure :

Groups of nine elements

Tefflux® candles are flexible, and can be bent without damage

Edition 3, Dec 2017 HOW DOES BACKPULSE FILTRATION WORK?

At regular intervals, automatically controlled by Δp, the brine is pushed backward through the membrane for a few seconds. The backflow expands the membrane pores and releases the impuri- tes caught inside the pores. At the same time, the shock effect of the backpulse breaks the « cake » of impurities accumulated around the candle, and let it falls to the bottom of the vessels. This process is similar to the cleaning of classic candle filters, but since no body feed is required, filtration can resume immediately at the end of the backpulse. Backpulses consume very little brine, and can be triggered at short intervals. The sludge accumulates at the bottom of the vessel, and is only flushed away when its level reaches a preset high level.

Purified brine Purified brine

Raw brine Raw brine

Brine bleed to tank

1- Filtering 2- Backpulse (decaking) 3- Filtering 4- Flushing

A complete system is usually composed of three vessels, each providing about 40% of the total capacity. The filters are backflushed in turn, so that a minimum of two filters are in production state at any one time.

For installation convenience, and to reduce at-site work during erection, TECHLINK supplies each filter unit as an independent skid with all its appurtenances. Three units are interconnected to make a complete filtration system

Edition 3, Dec 2017 MAGNESIUM RICH SEA SALT

Magnesium rich sea salt sets a challenge to classic brine preparation systems, because the magne- sium hydroxide does not separate in the settler if the concentration of magnesium is too high.

Magnesium hydroxide is difficult to filter out, because it forms a sticky slime on filter candles, which does not break away during backflush cycles.

Techlink and Profilco have devised a method to purify magnesium rich salt using Tefflux® nanome- tric membrane filtration.

IRON RICH EVAPORATED ROCK-SALT

Rock salt purified by evaporation will net go through the process of calcium and magnesium elimination, but it can nevertheless contain too much iron. Iron chloride is reacted with caustic soda to produce iron hydroxide Fe(OH)3, which, just like magnesium hydroxide, forms a sticky slime that is difficult to filter out.

Techlink and Profilco offer a system to removed the iron from the brine using Tefflux® nanometric membrane filtration.

BENEFITS OF THE TEFFLUX® MEMBRANE FILTRATION SYSTEMS :

■ SINGLE STEP FILTRATION ■ NN NEED FOR A SETTLER ■ NO NEED FOR PRIMARY FILTERS ■ NO PRE-COAT ■ NO BODY FEED ■ ZERO alpha-CELLULOSE ■ ENVIRONMENT FRIENDLY ■ UNBREAKABLE ELEMENTS ■ THREE YEARS MEMBRANE LIFE GUARANTEE

Edition 3, Dec 2017 CHLORINE GAS DEMISTERS BRINK® TYPE CANDLE FILTERS FOR WET CHLORINE / HYDROGEN / DRY CHLORINE

Vinyl-Ester FRP structure

Machine wound C-glass fibers, collection layer Titanium cage (wet chlorine) Drainage layer 316L cage (dry chlorine and hydrogen)

These demister candles are direct replacement for MECS® candles.

Third generation Brink® mist eliminators have overcome most of the problems of choking, high pressure drops, and dislocated glass fiber mats. The machine-wound filament fibers, with an additional coarse drainage layer, provide good chemical resistance, minimum pressure dorps, high collection afficiency, and, under proper operating conditions, a minimum of three to five years lifetime.

Cages are made of titanium for wet chlorine, and stainless steel for other applications.

Our candles may be rewound at site.

Edition 3, Dec 2017 RESIN TRAPS FOR PURIFIED BRINE

Resin traps are simple filration systems inserted between the outlet of the ion-exchange resin columns and the electrolyzer. They catch resin beads that leaked out of the column due to their sizes having become too small. The resin trap system consists of two bucket filters, built from materials having controlled magnesium and calcium content. The mesh is usually made of woven PTFE. The buckets are easy to switch over and inspect to monitor the amount of resin beads released from the column and caught in the filte- ring elements.

NICKEL FILTERS FOR CAUSTIC SODA Bucket and mesh type.

FILTERS FOR SODIUM CHLORATE Based on the TEFFLUX® nanometric pPTFE membranes

Removal of all suspended particles is a condition for the stability of sodium chlorate solutions and sodium hypochlorite. In particular, suspended particles of iron and chrome oxides must be removed. Conventional filtration uses large amounts of α‐cellulose as body‐ feed, which ends up as a cumbersome waste. The TEFFLUX® nanometric pPTFE membrane technology is ideal for obtaining a perfectly clear filtrate without using any body-feed and therefore minimizing the volume of solid effluents.

■ No pre-coat required ■ Reduces waste disposal cost ■ Simplified automation ■ Maximum product clarity ■ Minimum operating & maintenance cost

Edition 3, Dec 2017 French headquarters: Techlink Associated International Engineers 18 rue du 8 mai 1945, 59650 Villeneuve d’Ascq, France Contact : Mr. Stephan Misrachi Tel. : +33 320050045 Fax : +33 320419299 E-mail : [email protected] Website : http://techlink.fr/

India : Techlink International Process Engineers Private Ltd. L-301, Darshanam Antica, opp. Heavy Water Township, Tarsali, Vadodara 390009,India Contact : Mr. Prakash Tel. : +91 97259 09569 E-mail : [email protected] Website: http://www.tech-link.asia

Thailand office : 50/6 Moo 12, Bangna Trad Rd Km 6, Bangkaew, Bangplee, Samutprakarn, 10540 Thailand Contact : Ms. Suntharee Chumrit Tel. : +66 896606955 E-mail : [email protected]

China : Techlink Shanghai Ltd. Room306 & 307, N°758, Songsheng Road, Songjiang District 201613 Shanghai, P.R.China Contact : Ms. Amanda Zhou E-mail : [email protected] Tel. : +86 21 57783967 Fax : +86 21 57784017 Website : http://www.techlinkchina.com.cn/

Edition 3, Dec 2017