Wallace & Tiernan® Process Technology

Our world famous OSEC® (On Site Electrolytic Chlorination) Systems are used to provide a viable, efficient and safer alternative to the use of gaseous chlorine for water disinfection. 

We also have a range of TPC's or Totally Packaged Concepts.  TPC's come in a range of sizes designed to suit a variety of chemical dosing applications such as disinfection, phosphate removal, the treatment of septic sewage, plumbosolvency, orthophosphoric acid dosing to mention a few.

OSEC® System (On Site Electrolytic Chlorination)


The OSEC® On-Site Electrolytic Chlorination System produces sodium hypochlorite on site and on demand through the electrolysis of a brine solution. It is available in standard unit capacities ranging from 2 to 907kgs of equivalent chlorine per day. The system capacity can be increased by use of additional modular electrolysers.

The OSEC® System

For a more detailed description of the OSEC Product range and the OSEC process itself, see our Product Range brochure

  • View Chemical Feed & Disinfection Group Electrochlorination Systems

Also by way of an introduction to the Basic Principles of Electrochlorination, three Technical Papers are available.

These are:-

  • A Review of the factors affecting chlorine generation efficiency
  • The use of Sea Water as a feedstock for OSEC for disinfection of potable water
  • The importance of Bespoke Design of Electrolytic Chlorination for Brine Applications

 


OSEC-LC
A low-capacity system available in capacities of 6 & 12kgs of equivalent chlorine per day. Standard components are avail-able for wall mounting to custom fit in any location from small well houses to replacing small gas-feed systems.

  • View Technical Information
  • View Electrolyser Assembly
  • View Typical Installation


Mini OSEC2
The Mini OSEC2 is a completely pre-engineered and pre-packaged self-contained skid-mounted system designed for easy, low cost installtion and minimum maintenance requirements.

The Mini OSEC2 is available in two capacity options:-

  • A low capacity package that supplies up to 16.8kgs/Cl2/day
  • A high capacity package that supplies up to 34kgs/Cl2/day

Mini OSEC2 (Low Capacity)
A completely pre-packaged, self-contained system designed for easy low-cost installation. All components - with the exception of the salt saturator - are mounted on one skid, designed to fit through a 36-inch doorway.

  • View Technical Information
  • View Electrolyser Skid Assembly
  • View Typical Installation
  • View Product Specification


Mini OSEC2 (High Capacity)
A completely pre-packaged, self-contained high capacity sys-tem designed for easy low-cost installation. All components -with the exception of the salt saturator - are mounted on one skid.

  • View Technical Information
  • View Product Specification

Tubular OSEC ®

The tubular designed OSEC ® range has models that generate from 27 to 907kgs/day of chlorine equivalent. The tubular PVC electrolyser casing houses a titanium chassis to which the anodes and cathodes are fixed in a configuration that ensures maximum operational efficiency by providing a simple, once through flow operation. The internal electrolyser design and vertical orientation of the anodes and cathodes provides for the quick removal of hydrogen from the anode for maximum efficiency. The modular nature of this range means that the systems can be increased in capacity by adding extra electrolyser units.

The OSEC Electrolyser
At the heart of the OSEC system, the electrolyser provides the means to generate the sodium hypochlorite solution produced by the system. In order to maintain the electrolyser at its optimum generating efficiency certain criteria need to be followed.
Wallace & Tiernan provide a warranty on the anodes included within the electrolyser and for this to be valid the conditions indicated in our Technical Information sheet Anode Warranty must apply.


B1-150
A tubular design unit consisting of one six-inch (150mm) casing. Available capacities range from 21 to 67.2kg of Chlorine per day.

  • View Technical Information
  • View Electrolyser Skid Assembly
  • View Typical Installation
  • View Product Specification


B1-200
A tubular design consisting of one eight-inch (200mm) casing. Available capacities range from 71 to 113kg of Chlorine per day.

  • View Technical Information
  • View Electrolyser Skid Assembly
  • View Typical Installation
  • View Product Specification


B2-200
A tubular design consisting of two eight-inch (200mm) casings. Available capacities range from 118 to 227kg of Chlorine per day.

  • View Technical Information
  • View Electrolyser Skid Assembly
  • View Typical Installation
  • View Product Specification


B4-200
A tubular design consisting of four eight-inch (200mm) casings. Available capacities range from 235 to 454kg of Chlorine per day.

  • View Technical Information
  • View Electrolyser Skid Assembly
  • View Typical Installation
  • View Product Specification


B8-200
A tubular design consisting of eight eight-inch (200mm) cas-ings. Available capacities range from 470 to 907kg of Chlorine per day.

  • View Technical Information
  • View Electrolyser Skid Assembly
  • View Typical Installation
  • View Product Specification


OSEC System Auxiliary Plant Items

The OSEC range of products has a number of auxiliary plant items that can be included within the overall OSEC system as required.

For further information on these items please select from the following options :-

OSEC Hazardous Area Requirements
As OSEC generates hydrogen gas as one of its by-products, the design and installation of any OSEC system requires careful planning and reference to Hazardous Area Requirements.
Having pioneered the OSEC product, Wallace & Tiernan have had years of experience with this requirement and are pleased to be able to make recommendations when preparing for the implementation of an OSEC System.
Please refer to our Hazardous Area Requirements Technical Information Sheet for further details.


As a result of the combined efforts of the worldwide Wallace & Tiernan group of companies, our range of OSEC ® products has expanded to meet local customer requirements.



OSEC 'B' and 'S' series
Complete pre-packaged skid systems, models OSEC-B (brine) and OSEC-S (seawater) operate as tubular design open multi-stage once-through cells.

Strength of the prepared sodium hypochlorite solution is 2 g/l active chlorine in the seawater type and 6 ... 8 g/l active chlo-rine in the brine type electrolyser.

  • View Technical Information - OSEC B
  • View Technical Information - OSEC S


OSEC-NT
The model OSEC-NT operates with an electrolyser cell having an ion exchange membrane separating the anode and cathode compartments. It is now available in size 100-200g/h chorine and 500-5000 g/h chlorine.

The chlorine gas and the caustic soda generated in this elec-trolyser are passed to a reaction tower where a sodium hypochlorite solution containing approx. 30 g/ l active chlorine is produced. This solution is stored in a holding tank from which it is dosed by metering pumps to the point of application.

  • View Flash Movie
  • View Technical Information
  • View System Overview
  • View Typical System OSEC-NT 500
  • View Typical System OSEC-NT 1000
  • View Typical System OSEC-NT 1500
  • View Typical System OSEC-NT 2000 Version A
  • View Typical System OSEC-NT 2000 Version B
  • View Typical System OSEC-NT 2500
  • View Typical System OSEC-NT 3000
  • View Typical System OSEC-NT 4000 Version A
  • View Typical System OSEC-NT 4000 Version B
  • View Typical System OSEC-NT 5000
  • View Typical Installation OSEC-NT 500
  • View Typical Installation OSEC-NT 1000
  • View Typical Installation OSEC-NT 1500
  • View Typical Installation OSEC-NT 2000 Version A
  • View Typical Installation OSEC-NT 2000 Version B
  • View Typical Installation OSEC-NT 2500
  • View Typical Installation OSEC-NT 3000
  • View Typical Installation OSEC-NT 4000 Version A
  • View Typical Installation OSEC-NT 4000 Version B
  • View Typical Installation OSEC-NT 5000


Alternative Disinfection Systems

Chlorine Dioxide is used for water disinfection as an alternative to chlorine gas. Chlorine Dioxide is a powerful disinfectant and excellent at destroying odours. This chemical has a considerably higher oxidising reduction potential than chlorine and can achieve destruc-tion of such organic substances, virus, and spores which are not attacked by chlorine. Its sporicidal and virucidal effect is higher than that of chlorine at the same strength.

Use of Chlorine Dioxide does not result in the formation of undesirable or harmful tri-halomethanes or AOX.

It oxidises or reduces to neutral unpleasant compounds or noxious substances found in water such as phenols, algae, or products resulting from their decomposition.

Unlike chlorine the rate of disinfection by chlorine dioxide increases with rising pH. Chlorine Dioxide is capable of maintaining an active residual for a longer time than chlo-rine. This advantage of stability helps to protect remote sections of distribution systems and to prevent bacterial re-growth. Chlorine Dioxide is also successfully applied in warmwatersystems to fight legionellas. Chlorine Dioxide is generated on site as an aqueous solution in special equipment as shown below.


DIOX-A250
Chlorine Dioxide Generating and Metering Equipment -Acid/ Chlorite Process using dilute reagents The Wallace & Tiernan Chlorine Dioxide Generator DIOX-A250 was developed for the preparation of chlorine dioxide up to a capacity of 250 g/h.

As basic chemicals for the generation of chlorine dioxide this unit uses dilute hydrochloric acid (9 % HCl) and dilute sodium chlorite (7.5% NaClO2). Both reagents are metered directly from commercial carboys or intermediate storage tanks into the reaction tower where a chlorine dioxide solution is produced.

The strength of the two basic chemicals is balanced in a ratio that ensures an optimal yield of chlorine dioxide. The chlorine dioxide solution produced is directly metered via an injection unit into the water to be treated.

  • View Technical Information
  • View Typical Installation - Mains Pressure Application
  • View Typical Installation - Booster Pump Application


DIOX-A5000
Chlorine Dioxide Generating and Metering Equipment -Acid/ Chlorite Process

The Wallace & Tiernan Chlorine Dioxide Generator DIOX-A5000 was developed for the preparation of chlorine dioxide up to a capacity of 5000 g/h. As with the DIOX-A250 the basic chemicals for the generation of chlorine dioxide are dilute hydrochloric acid (9 % HCl) and dilute sodium chlorite (7.5% NaClO2).

Both reagents are metered directly from commercial carboys or intermediate storage tanks into the reaction tower where a chlorine dioxide solution is produced.

The strength of the two basic chemicals is balanced in a ratio that ensures an optimal yield of chlorine dioxide. The chlorine dioxide solution produced is directly metered via an injection unit into the water to be treated.

  • View Technical Information

DIOX-C1500 / 4500
Chlorine Dioxide Generating and Metering Equipment - Gas Process

The Wallace & Tiernan chlorine dioxide generator DIOX-C is designed for the preparation of high capacities of ClO2 solution. As basic chemicals for the generation of ClO2 this unit uses sodium chlorite (NaClO2) and chlorine gas (Cl2).

The commer-cial strength NaClO2 solution is metered directly from a carboy or an intermediate tank. The standard skids are available to produce a chlorine dioxide capacity of 1500 - 4500 g/h ClO2.

  • View Technical Information

Packaged Systems

With the flexibility of worldwide resources available, the range of Packaged Systems clearly demonstrates Wallace & Tiernan's desire to provide a complete customer-oriented process, backed by competitive pricing and exceptional after-sales service.

As a result, Wallace & Tiernan part of the Chemical Feed & Disinfection Group have put together a wide selection of packaged systems for installation in a wide variety of applications. The following are just a selection of the systems already completed as an illustration of the Group’s capability and expertise.

Water & Wastewater Treatment Applications

  • Simple Skid Mounted Pump Packages
  • Skid Mounted Dosing Packages
  • Polymer Preparation Systems
  • Sodium Hypochlorite Generation Systems
  • Chlorine Dioxide Generation Systems
  • Chemical Dosing Installations
  • Prefabricated Kiosk Installations
  • Electrical Control Panels

Industrial Water & Wastewater Treatment Applications

  • Skid Mounted Dosing Systems
  • Polymer Preparation Systems
  • Industrial Gas Handling Systems
  • Electrical Control Panels

 

 

Level, Usage and Feed Rate Monitoring

Merlin® Dilution By Weight Systems

Dilution by Weight Technology: MASS BASED + MICRO BATCH


Like buying orange juice and detergents, water treatment chemicals are almost always less expensive to purchase in higher concentrations. Unfortunately, feeding high strength chemicals into process water can create problems for the water treatment operator. These problems may stem from things like extremely low feed rates, chemical gassing-off, ambient temperature conditions, very hard process water and health & safety concerns in handling high strength chemicals.

By combining a microprocessor based controller with an instrument grade load cell, the MERLIN® automatically creates small weight-based batches on demand to achieve dilution ratios of up to 1000:1. With this "Mass Based + Micro Batch" technology, users now have a safe, easy and accurate way of diluting high strength water treatment chemicals onsite.

 

(Merlin.pdf - 120k)

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