VERTICAL COUNTER-FLOW (VCF) SCRUBBERS

Whether it be a small compact system for a laboratory or test plant or a large multi-stage complex system for a metallurgical processing facility Polimatrix has the necessary expertise and skills to offer our clients the right solution to their air pollution problems. Through our partnerships with various South African and International companies we are able to provide an economical, cost effective and reliable solution for the majority of odour and fume scrubbing applications.

Polimatrix provides standard and custom Fume (Gas) Scrubbing solutions for various applications.

VCF Scrubbers feature one or more vertical columns mounted on a base section which also serves as the tank for the scrubbing solution. VCF Scrubbers may have one, two or three packed bed sections depending on the application. The packed bed is filled with various Tower Random Packing types to suit the intended application. The Tower packing is available in various plastic materials, ceramic and metals. The contaminated fumes (gas) enter the column below the packed bed and are drawn up the column through the packed bed. A scrubbing solution is distributed across the top of the packed bed and filters down through the packing creating a liquid film on the surface of the packing material. This is known as a counter-flow system. The large, whetted surface area provides the contact point for scrubbing (absorption, mass transfer) to take place. The total basic scrubber system comprises the Scrubber Column and Tank, a Circulation Pump, an Extraction Fan, a Chemical Dosing system and an Exhaust Stack.

VCF Scrubbers are ideally suited for the following applications:

  • Chlorine Gas Scrubbers
  • Complex mixed chemical fume scrubbers
  • Very high removal efficiency applications
  • H2S Fume Scrubbers
  • HF Fume Scrubbers
  • NOx Fume Scrubbers
  • High Volume scrubbers requiring a small footprint
  • Fume scrubbers which require longer retention time to scrub efficiently (multiple packed bed)
  • Low volume odour scrubbers

Main Areas Of Application:

  • Water Treatment
  • Rendering Plants
  • Waste plants
  • Mineral Processing Plants (Mining and Industrial)
  • Metal Finishing (Galvanizing, Anodizing, Plating etc)
  • Chemical Production
  • Research Laboratories
  • Commercial and Industrial Laboratories
  • Forensic Laboratories
  • Designs to solve unique process applications
  • Unique Features
  • Basic Components
Unique Features

POLIMATRIX ALWAYS INSTALLS THE EXTRACTION FAN ON THE CLEAN SIDE OF THE SCRUBBER.

This ensures that the duct and column containing contaminated air are always under negative pressure so that no contaminated air can escape the system. It also increases the longevity of the fan and ease of fan maintenance resulting in lower operational costs.

ALL POLIMATRIX SCRUBBERS FEATURE A CARTRIDGE TYPE DEMISTER ARRANGEMENT.

This eliminates the need to remove the top or end section of a fume scrubber to access the demister for inspection and maintenance. This reduces the time required for maintenance and inspection and makes this a low safety risk operation. The maintenance personnel are not directly exposed to the fumes inside the scrubber.

IN-LINE pH, ORP and CONDUCTIVITY MEASUREMENT.

Polimatrix utilizes an in-line bypass arrangement for the installation of pH, ORP and Conductivity sensors where these are required. This arrangement allows for accurate measurement of the scrubbing solution without the effect of “dead” areas within the tank and ensures that the scrubbing solution is always maintained within the optimum range. Eliminates the risk of leaks at threaded joints in the tank wall.

THERE ARE OTHER PROPRIETARY FEATURES WHICH GREATLY REDUCE MAINTENANCE AND INCREASE EASE OF OPERATION AND TOTAL EFFICIENCY SPECIFIC TO EACH SCRUBBER TYPE.

These features will be highlighted when Polimatrix discusses the application with each client.

Basic Components

Scrubber Base Tank:

On smaller diameter columns it Polimatrix standard to manufacture the base tank a larger diameter to provide a stable support for the column.

Lower Column Section:

  • The Gas Inlet Nozzle (the extraction duct connects to this nozzle).
  • A Sight Glass Nozzle. This sight glass nozzle provides visual inspection of the liquid flow as it drains through the Gas Injection Support Plate and in medium to large scrubbers it also serves as a man-way access to the scrubber base tank.
  • The Gas Injection Support Plate. This supports the tower packing and is specially designed to provide a low pressure drop and maximum air diffusion across the packed bed.

Middle Column Section:

  • A Lower Sight Glass Nozzle. This sight glass nozzle serves as an inspection point at the base of the packed bed and as a packing removal point. In the case of multiple backed beds each packed bed will have such a nozzle.
  • An Upper Sight Glass Nozzle. This sight glass nozzle provides visual inspection of the liquid distribution over the top of the packed bed and as a loading point for replacement packing. In the case of multiple backed beds each packed bed will have such a nozzle.
  • The Tower Packing Material. This tower packing is of the “random” type in that the injection moulded or formed packing shapes are supplied in bulk and the column is filled to the required design height. The individual packing pieces are thus randomly arranged throughout the packed bed providing maximum liquid and gas distribution and thus maximum contact area.

Top Column Section:

  • The Liquid Distributor. Liquid distributors come in various forms depending on the contaminant being scrubbed, the diameter of the column and the liquid flow rate required. Their primary function is to evenly distribute the scrubbing solution over the packed bed to maximize wetting of the packing and to eliminate channelling (uneven flow through the packing resulting “dry” areas). The three main types of distributors are: Spray, Ladder and Trough types. There are many variations within and combination of these main types in order to maximize distribution. Correct liquid distribution is absolutely critical to a successful scrubber design.
  • A Demister (Droplet Eliminator). This is the final stage in the scrubber column and is required to remove liquid droplets carried up by the airstream. This is critical to reduce water losses through the scrubber and to extend the life of the scrubbing solution. The demister can be in the form of a knitted mesh pad (plastic or metallic) or a chevron plate configuration (plastic or metallic). Selection is based on each particular scrubber design. The most common demister used is a knitted mesh pad usually in Polypropylene.
  • Column Exhaust Nozzle. This nozzle is the outlet from the top of the column and is connected to the duct which is in turn connected to the extraction fan.

Extraction Fan

In the majority of cases this fan will be a COLASIT fan in a corrosion resistant thermoplastic material suited to the application. This fan will discharge into an exhaust stack.

Circulating Pump

This pump circulates the scrubbing solution and can also be used for blow-down (partial dumping of spent/contaminated scrubbing solution) and draining/transfer of the scrubbing solution. These pumps feature corrosion resistant materials of construction suited to each specific application

Most custom designed equipment is for use in one-off applications. These applications require a unique understanding of the various engineering plastic materials, solid design experience and an intuitive understanding of the practical application of the equipment.

Open and honest communication with our clients ensures that there is a full understanding of what is expected and what can be achieved.

Such projects are uniquely challenging but in the end very rewarding for both the client and Polimatrix.

Contact Polimatrix to discuss your unique requirements and we will gladly assist you.

ENQUIRE

ADDRESS:

1047 Katrol Ave, Robertville,

Roodepoort, Gauteng

CONTACT DETAILS:

Phone: (+27) 11 672 2101

Fax: (+27) 11 672 8628

Email: enquiries@polimatrix.co.za