Process Units And Process Packages

All Items
Water Treatment
Oil Treatment
Gas Treatment
Additional Packages
Water Desalination

Water desalination processes separate dissolved salts and other minerals from water. Different processes are used for this matter, such as vacuum distillation and membranes to desalinate. Reverse osmosis (RO) and Nano filtration (NF) are the leading pressure driven membrane processes. Conventional macro-filtration of suspended solids is accomplished by passing a feed solution through the filter media in a perpendicular direction.

Examples of such filtration devices include:

- Cartridge filters

- Bag filters

- Sand filters

- And multimedia filters.

Macro-filtration separation capabilities are generally limited to undissolved particles greater than 1 micron.

For the removal of small particles and dissolved salts, crossflow membrane filtration is used.

Membrane Distillation (MD) is a water desalination membrane process. MD is a hybrid process of RO and distillation in which a hydrophobic synthetic membrane is used to permit the flow of water vapor through the membrane pores, but not the solution it. The driving force for MD is the difference in vapor pressure of the liquid across the membrane.

NORDEN design water treatment package using any above mentioned method or sometime combination of them according to customer specifications, last thing to mention is that our packages maintenance costs are very economical.

Oil Treatment

NORDEN offers a range of crude oil dewatering and desalting technologies that cover most typical processing requirements depending on the salt level required. These include:

  • Free water knock out drums
  • Heater treaters
  • Dehydrators
  • Coalescers
  • Electrostatic desalters
  • Degassers

Following primary oil/water separation crude oil still contains residual amounts of water containing unwanted salts that need to be removed in order to avoid undesirable effects downstream such as fouling.

Automated Oil Treatment Packages are designed for gathering and treatment of fluids from oil producing wells by providing deep dehydration, desalting and oil vapor pressure reduction to achieve the required quality of marketable oil and that of separated water.

The benefits and features of our electrostatic and mechanical treats include:

  • Low maintenance
  • Excellent turn-down performance
  • Adjustable for load and voltage resulting in high operational flexibility
  • Effective design means minimal chemical treatment
Glycol Dehydtarion / Regeneration

Glycol dehydration has stood the test of time as the preferred way to remove water from natural gas to avoid corrosion or pipeline plugging due to ice or hydrate formation. ETHYLENE GLYCOLS (mono, di and tri ethylene glycols) are commonly used to remove water from gas streams, which significantly reduces the risk of hydrate formation. 

Gas Dehydration

The traditional way to dehydrate natural gas is by absorption in triethylene glycol (TEG). Normally, the water is removed from the (rich) glycol by distillation, and then the regenerated glycol is recycled back to the absorption Column. Wet gas to be dehydrated enters the glycol contactor, close contact with the glycol by means of bubble cap trays, as this type of trays hold its liquid seal both at the low liquid loadings inherent in a glycol unit and under turn down conditions as regards gas flow rate.

NORDEN designs and builds Gas dehydration Package by considering following specifications:  1-Discharge gas moisture content, 2-High gas dehydration capacity, 3-Minimum glycol losses, 4-Minimum power consumption, 5-Optimum plant efficiency and design integrity, 6-Compliance with SHEQ requirements.

Glycol Regeneration

NORDEN custom designs glycol regeneration packages to recondition glycol used for processes such as hydrate inhibition and gas dehydration. The Rich MEG contains significant quantities of water, dissolved salts and other contaminants. NORDEN custom designs glycol regeneration systems to strip the absorbed water, salts, and contaminants from the Rich MEG to produce Lean MEG that can be recycled to the system again. After absorption, soluble gases like CO2 are first released from the glycol in a flash tank, and then the glycol is heated before it flows to a distillation (regeneration) column.

The simplest way to reduce the water content in the glycol, is to introduce stripping gas to the regeneration column. The stripping gas can be nitrogen, recycled natural gas or flash gas (from the flash tank after the absorption column).

Chemical Injection Packages

The purpose of injecting the chemicals into a system is to protect the mechanical integrity of the system from accelerated corrosion and prevent scale formation. The aim is also to control hydrate formation, prevent oxygen induced corrosion, emulsion breaker for rapid and sharp separation of water from oil, reduce wax formation, water treatment, Odorization, foam control and etc.

NORDEN specializes in designing and manufacturing all types of chemical injection packages in line with customer requirements and standards. Such as Corrosion inhibitors, Demulsifiers, Oxygen scavengers, Methanol, Glycol (EG, MEG, TEG), etc.

Chemical injection packages are used for onshore and offshore plants. Most common onshore packages for the oil and gas industry are used for flow assurance pour point depressants, antifoaming agents, wax inhibitors, polymers, scale, corrosion inhibitors and hydrate inhibitors. These agents are injected at high pressures to maintain oil flow and protect oil pipelines and most common packages for the water and waste water industry are for the water treatment. These injection packages form the major part of the water treatment systems and are normally utilized to inject, ammonia, hydrazine, caustic, sodium hypochlorite, phosphate, amine and PH adjustment chemicals.

On the offshore platforms where there is always a space constraint and the need for injecting different chemicals at different injection point, pressure and flow, compartmental tanks for storing different chemicals can be used and by using different pumps with number of flow control devices to inject different chemicals at different pressures and flow rates.

NORDEN can advise optimized designs for a variety of applications, taking into account challenging plot size and weight restrictions. Our systems can include flow, level and pressure instrumentation for local and/or remote indication.

Steam Condensate Polishing

Condensate polishing is a proven method of producing high purity, which can be economically returned to an ultra-pure state by simple polishing rather than using fresh make up process water. The design of condensate polishing system will be influenced by Steam cycles, Site conditions, Space considerations, Cooling water availability and temperature, Material of construction (used in condensers, Pumps, Ancillary equipment’s & Piping) and lastly by engineering requirements by the Client.

Two type of condensate will be produced in plants:

1-Hot condensate

2-Cold condensate

Treatment of hot and cold condensate have similarities and differences. The “suspect” hot condensate may contain oil and an additional kind of contamination of the condensate is due to possible dissolved solids content. Therefore, in order to assure the required quality of the Boiler Feed Water and of the produced steam, feeding the turbines, a deoiling and Polishing Treatment on Mixed Beds Filters preceded by Activated Carbon shall be also provided.

Generally below processes are used in a Condensate Polishing Unit: PROCESS CONDENSATE DE-OILING, CONDENSATE COOLING, CONDENSATE STORAGE & PUMPING, PROCESS CONDENSATE hc-ADSORBING and MIXED BED POLISHERS.

Crude Oil Desalter

Purpose of crude oil desalting

The purpose of desalting is to remove undesirable impurities, especially salts and water, from the crude oil prior to distillation.

Benefits of Crude Oil Desalting is as following: 1-Increase crude throughput, 2-Less plugging, scaling, coking of heat exchanger and furnace tubes, 3-Less corrosion in exchanger, fractionators, pipelines, etc., 4- Better corrosion control in CDU overhead, 5- Less erosion by solids in control valves, exchanger, furnace, pumps, 6-Saving of oil from slops from waste oil.

Desalting process

The desalting process is completed in following 5 steps: Dilution water injection and dispersion, Emulsification of diluted water in oil, Distribution of the emulsion in the electrostatic field, Electrostatic coalescence and Water droplet settling.

The oil/water mixture is homogenously emulsified in the emulsifying device. The emulsion enters the Desalters where it separates into two phases by electrostatic coalescence.

The electrostatic coalescence is induced by the polarization effect resulting from an external electric source. Polarization of water droplets pulls them out from oil-water emulsion phase.

A desalting unit can be designed with single stage or two stages.  In the refineries, the two stages desalting system is normally applied, that consists of 2 electrostatic Coalescers (Desalter).

Gas Sweetening

NORDEN offers a range of solutions to remove acid gas components (CO2 and/or H2S) from natural gas customized to meet each client’s specific process requirements. The most common methods for acid gas removal are via amines, physical solvents, or membranes, the choice of which depends on the levels of impurities to be removed.

NORDEN works with major solvent suppliers such as Ineos, BASF and Dow and membrane providers such as UOP to ensure each plant is optimized to: 1- Meet sales gas CO2 and H2S specifications, 2-Remove impurities to minimize foaming, 3-Operating efficiency, 4-Materials compatibility, 5-Minimize solvent losses

NORDEN provides the analysis, and recommends the most cost effective solution.

H2S & CO2 are removed from the gas stream in the Amine Contactor. Then the Rich Amine is regenerated in the Amine Regenerator, and recycled to the Amine Contactor. The sour gas streams enter to the Amine absorber in contact with lean Amine flow. The sour gas flows upward counter-current to the lean amine solution. An acid-gas-rich-amine solution leaves absorber to the Amine Regenerator. The sweet gas, after absorption of H2S and CO2 by the amine solution, flows overhead from the Amine Absorder. Acid gas, primarily H2S and water vapor from the regenerator is sent to Sulfur Recovery.

The amine concentration in the absorbent aqueous solution is an important parameter in the design and operation of an amine gas treating process. Depending on gas specification different amine type will be used. following are typical amine concentration which will be used for specific gas purity:

  • Monoethanolamine: About 20 % for removing H2S and CO2, and about 32 % for removing only CO2.
  • Diethanolamine: About 20 to 25 % for removing H2S and CO2
  • Methyldiethanolamine: About 30 to 55% % for removing H2S and CO2
  • Diglycolamine: About 50 % for removing H2S and CO2

 The choice of the type of amine will affect the required circulation rate of amine solution, the energy consumption for the regeneration and the ability to selectively remove either H2S alone or CO2 alone if desired.

Drain

All waste water effluents from the industries which are discharged to public and/or natural water sources or directed to recycling purpose inside the industry and may contain a wide variety of matters in solution or suspension should be controlled according to the requirements imposed by the final destination.

Drain systems

In any case elimination of the waste or the hazard potential of the waste shall be ultimate goal in the management of hazardous wastes. Under no circumstances shall the effluent water cause oil traces on the surface or embankments of the receiving water, or affect the natural self-purification capacity of the receiving water to such an extent that it would cause hindrance to others. Under no conditions shall polluted streams be combined with unpolluted streams if the resultant stream would then require purification. In general main sewer systems in the industry are specified as:

  • Storm Water Sewer System.
  • Oily Sewer System.
  • Oily Water Sewer System.
  • Non Oily Water Sewer System.
  • Chemical Sewer System.
  • Sanitary Sewer System
  • Special Sewer Systems

NORDENs features is: all areas including process, offsite and utility Units, provisions shall be made to foresee any of the above mentioned sewer systems as required. Also Drain systems are separated in to two sections “Closed drain system” and “Open drain system”. Process fluids contained in equipment must be collected when equipment are emptied for their maintenance.

APPLICATION TYPES

INDUSTRIAL SEWER SYSTEMS will be included of pipes and open ditches for collecting sewers from various parts of the plant. And will be drained to drain system which consists of a drum and circulation pumps as minimum. The storm water shall be disposed to the oily storm water basin located in the waste water treatment area through the storm water network.

 

Evaporators

The Wide Production Of Evaporators Of NORDEN allows proposing the most suitable Evaporators for plant requirements.

Evaporator Consists Of A Heat Exchanger For Boiling The Solution With Special Provisions For Separation Of Liquid And Vapor Phases.  Operating costs are related principally to the Cost Of Heat, and, to a lesser extent, The Cost Of Utilities (Cooling Water, Electricity, Etc.) and Water Treating Chemicals. Heat (Energy) Costs Are Relatively Independent Of The Feed Water Composition.

TYPE OF EVAPORATORS are:

FALLING FILM EVAPORATORS Known As Vertical Shell-And-Tube Heat Exchanger With Laterally Or Concentrically Arranged Centrifugal Separator. 

FORCED CIRCULATION EVAPORATORS Known As Horizontal Or Vertical Shell-And-Tube Heat Exchanger Or Plate Heat Exchanger, With Flash Vessel/Separator, Circulation Pump.

PLATE EVAPORATORS Known As Plate Heat Exchanger, Separator. A Plate-And-Frame Configuration Employs Special Plates, With Alternate Product And Heating Channels. The Plates Are Sealed.

CIRCULATION EVAPORATORS Vertical Shell-And-Tube Heat Exchanger Of Short Tube Length, With Lateral Separator Arranged At The Top. The Liquid To Be Concentrated Is Supplied To The Bottom And Rises To The Top Of The Heating Tubes In Accordance With The “Mammoth Pump” Or Rising Film Principle.

Mol Sieve Dehydration

Molecular Sieve Dehydration Units work on the principle of adsorption.  Molecular Sieve Dehydration units typically have higher initial capital investments than comparable glycol units but also are able to achieve very low dew points which are required for cryogenic plants.  Additionally, Molecular Sieve Units can also handle large flow variations as well as higher inlet gas temperatures. Where very low water dew points are required molecular sieve dehydration is the preferred technology over glycol dehydration.

Norden Custom designs and builds each system as a complete turn-key package with particular emphasis given to: 1-Discharge gas moisture content (very dry gases specification) and Optimized absorption cycles, 2-Reduced maintenance via the use of specialty equipment, such as Rising Stem Switching Valves Minimum power consumption, 3-Optimum plant efficiency and design integrity (energy saving), 4-Compliance with SHEQ requirements, 5-Environmentally conscientious design. Because certain molecular sieves preferentially adsorb water, water is adsorbed in to the sieve as vapor or liquid passes thru a column. As the vapor or liquid continues to move through the column, more water is removed. Over time, the column will reach a saturation limit, at which point the column will be regenerated.

When properly designed, a molecular sieve system can selectively separate water from other molecules such as alcohols and other solvents. The water holding capacity of the molecular sieve is dependent upon several variables, but typically has a maximum capacity of 22 wt% water per unit weight of mole sieve.

Regeneration in this case is accomplished by reducing the pressure, by pulling a vacuum on the column and/or increasing temperature, while using a purge gas to help strip the water out of the molecular sieve beds. Regenerating the sieve typically involves 1) draining the liquid, 2) heating the sieve beads, 3) gas purging either at pressure or vacuum, and lastly, 4) cooling the sieve.

NORDEN MSDUs are high efficiency designs providing:

  • Recovery rates of 90-95%  (low energy use)
  • Minimal Labor/operator intervention 
  • Designed to handle a wide variation in feed concentrations (0-10% water, 15% possible).
  • High Purity up to 99.95% dehydration
  • Process from ½ gpm to over 25 gpm of wet solvents
  • Packaged Units, fully piped, wired
  • Basic process is very simple, reducing labor and training.
Incinerators

Several kinds of incinerators are designed and manufactured by NORDEN as follows:

  • STATIC INCINERATORS for the incineration of gaseous, liquid and solid wastes
  • ROTARY INCINERATORS for the incineration of solid waste
  • MULTIPLE HEARTH INCINERATORS for the incineration of sludge

STATIC INCINERATORS:

Static incinerators for gaseous wastes consist usually of a vertical cylindrical chamber internally lined by refractory material with alumina content which varies with the type of waste to be burnt. and its main applications are for Gas and liquid waste of oil and petrochemical industries, Polluted gas and liquid streams and Solvents and paintings. The static incinerator for solid wastes is essentially used for the burning of small quantities of wastes (max 200 kg/h) particularly in the field of hospital wastes.The system is composed by three chambers:

  • Primary chamber
  • Secondary chamber with the grate
  • Post-combustion chamber

ROTARY INCINERATORS FOR SOLID WASTE (up to 80 t/d):

The rotary incinerator suitable for Hazardous and non-hazardous industrial solid wastes and Hospital wastes, consists principally of a revolving cylinder inside lined with refractory materials slightly inclined to the horizontal and supported by two riding rings resting on two trunnion rolls. In function of the type of waste to be burnt, in a wide range of temperature (from approx 800 °C to 1100 °C). The volatile products (flue gases with gaseous unburnt organic compounds and particulates) resulting from the thermal process occurring in the rotary chamber, are drawn into the Post-Combustion Chamber for a further oxidation. Flue gas treatment system: consists of: flue gas cooling system, pollutant removal system and ash removal.

MULTIPLE HEARTH INCINERATORS- consists of a vertical cylindrical shell lined with refractory which encloses a series of horizontal circular hearths. These type of incinerators are good for  Incineration of chemical and biological sludge,  Incineration of refinery sludge, Activated carbon regeneration and Foundry sands regeneration.

Waste Water Treatment - CPI Units

CPI (Corrugated plate interceptor) or TPI (Tilted plate interceptor) separators are predominantly used in separation of free oil from effluent water or suspended solids for oily water treatment in an OWS (oily Water System).

NORDEN CPI Units are designed to remove free oil and suspended solids from water as a primary stage of water treatment and utilize plate packs as the main separation device. The plate packs are designed with specific spacing and alignment to allow solids to settle and fall to the bottom while simultaneously allowing oil drops to rise and coalesce, thereby reducing the oil and solids loading from the downstream water treatment train and smoothing out flow slugging.

The basic principle of difference in gravity between the phases (liquid – liquid or solid – liquid) is employed in an OWS in separation of the two phases. This phenomenon is defined as “Gravity Separation”.

The effectiveness of this technique is subjected to various factors such as difference in the density, viscosity, factors of the medium, temperature, turbulence, and also the nature of impurity etc.

In some cases chemical coagulation and flocculation is needed for removal of the impurity by making them heavier or lighter.

Fuel Gas Treatment

NORDEN Fuel Gas Conditioning packages process gas to ensure it is free of liquids and solids. This is particularly critical in gas turbine applications where severe damage may be caused to the turbine if the gas is not ultra clean and dry. Metered fuel gas is normally required at a steady operating pressure and at a safe margin above dew point.


NORDEN supply complete modules with minimum installation time and costs and to maximize ease of operation, for the provision of clean, dry, metered gas at the required pressure and temperature from an untreated, unregulated gas source.

Fuel Gas Treatment packages are used in many applications to provide specific pre-treatment of gas feed streams different processes such as:

  • Utility fuel and instrument gas systems
  • Offshore power generators
  • Cement plants
  • Gas turbine power stations

NORDEN  Fuel Gas Treatment packages  includes a combination of equipment such as:

  • Knock-out drums / Filter/coalescers / Heaters
  • Pressure adjustment (reduction or compression) / Gas metering/ Gas storage systems
  • Condensate handling
  • Emergency shutdown systems
  • Vent and flare stacks / Process control systems

 

Metering

NORDEN supply Fiscal Metering Systems, Allocation Metering and Custody Transfer Metering Systems for a wide range of fluids including oil, gas and condensate. Typical applications include production, transmission/distribution pipelines, import/export for oil, gas and LNG terminals and storage facilities.

These packages are provided compliant with DECC & NPD requirements for fiscal measurement requirements in scope of supply. Our computation and reporting packages can range from simple flow computer to full supervisory systems with graphical control functions and communication with DCS, ICSS or other systems. 

All of our systems are built, assembled and flow tested at our own fabrication facilities

  • Bi-Directional Provers
  • Compact Provers
  • Analyser Packages
  • Ancillary Equipment
  • Diagnostics
Waste Water Treatment - Deoiling Hydrocyclones

Hydrocyclone based process systems are the most cost-effective solution for produced water treatment clean up. Located directly downstream on the water outlet of the production separator and upstream of the water level control valve, these systems operate in a proportional “pressure ratio” control manner.

NORDEN’s proprietary Deoiling Hydrocyclones are highly efficient in recovering oil from produced water and other process streams. Deoiling hydrocyclones have established themselves as standard oil recovery equipment.

We offer Deoiling Hydrocyclones in the following range of materials so you can be sure that they are suitable for your application no matter how severe the service:

  • Duplex stainless steel
  • Super Duplex stainless steel
  • tungsten carbide 
Carbon Capture Packages

The Carbon Capture technology which we employ can be used for any exhaust gas system including coal or gas power stations, coal or gas-fired boilers, gas turbines, blast furnaces and cement kilns. The technology enables CO2 to be selectively absorbed from flue gas via contact with a regenerable solvent, which is specially design to selectively absorb CO2 from gas streams.

Whether you are looking for a small or large-scale Carbon Capture plant, NORDEN designs and builds each system as a complete turn-key package with particular emphasis on:

  • CO2 product quality
  • Minimum solvent losses / Minimum utilities consumption
  • Efficient integration with existing plant and processes
  • Environmentally conscious design

Carbon capture and storage (CCS) (or carbon capture and sequestration) is the process of capturing waste carbon dioxide (CO2) from various large point sources. The goal is to prevent the release of large quantities of CO2 into the atmosphere. Although CO2 has been injected into geological formations for several decades for various purposes, including enhanced oil recovery, the long term storage of CO2 is a relatively new concept.

Conclusions of the scientific community indicate that the capture of carbon dioxide (CO2) emissions from polluting industries is essential in realizing global targets to decrease greenhouse gas emissions to the atmosphere.

Dryers / Calciners

NORDEN’s technology of dryers’ production allows proposing, for each type of product to be treated, the most suitable thermal dryer, such as:

  • Direct Rotary Dryers which can use as heating media: the material in direct contact with combustion gases, normally in counter-current way is brought up to 1200 ~ 1300 °C. The calciner consists in a revolving cylinder made with carbon steel plates internally refractory lined.
  • Indirect Rotary Dryers which are internally contained to a refractory furnace which is crossed by flue gases, for carbon black drying. the material is heated up to 1100 °C by combustion gases which cross a furnace. Indirect calciners are used when the product cannot come in direct contact with combustion gases and when it is requested to operate in a controlled atmosphere. The indirect calciner consists principally in a revolving cylinder, made of special alloys, housed, along its active length, in a refractory lined steel furnace.
  • Steam Tube Rotary Dryers for melamine and soya bean. The steam tube rotary dryer consists principally of a revolving cylinder, slightly inclined to the horizontal, supported in two riding rings resting on two trunnion rolls each.
  • Flue Gas Tube Rotary Dryers for drying of dusty materials with initial low moisture, such as talcum and carbon.

    In the flue gas tube rotary dryer, flue gas at the generator outlet enters a series of tubes located into the rotating cylinder in concentric circle. The material to be dried passes countercurrent to the gases and externally to the tubes.

Waste Water Treatment - Gas Flotation

Induced Gas Flotation (IGF) is a water treatment process that clarifies wastewaters (or other waters) by the removal of suspended matter such as oil or solids. The removal is achieved by injecting gas bubbles into the water or wastewater in a flotation tank. The small bubbles adhere to the suspended matter causing the suspended matter to float to the surface of the water where it may then be removed by a skimming device.

Induced Gas Flotation is very widely used in treating the industrial wastewater effluents from oil refineries, petrochemical and chemical plants, natural gas processing plants and similar industrial facilities. A very similar process known as dissolved air flotation is also used for wastewater treatment. Froth flotation is commonly used in the processing of mineral ores.

The feed water to the IGF float tank is often (but not always) dosed with a coagulant (such as ferric chloride or aluminum sulfate) to flocculate the suspended matter.

Some IGF unit designs utilize parallel plate packing material to provide more separation surface and therefore to enhance the separation efficiency of the unit.

NORDEN specialize in the design & build of turnkey water treatment process plant; therefore non-standard equipment and specifications can be easily incorporated into full treatment packages. This ensures our clients requirements are met in the most efficient manner either by incorporating standard plant or a bespoke design.

 

 

Ethylene Recovery

To recover, purge gas passes through Ethylene Recovery Package which usually includes compressor or ejector if pressure is not enough for further process. This unit should be isolated by means of isolation valves. The main objective of this package is to remove impurities from purge gas and to separate Ethylene with 99.9% volume fraction for further use into the plant. Different processes are known for Ethylene Recovery such as membrane technology and distillation. Herein after NORDEN’s technologies are briefly described.

Distillation:

In the first step, purge gas is passed through dehydration absorber or suction drum prior to compressor to eliminate the probable liquid particles. Purge gas pressure is increased via compressor and then routed to coalescer filters and carbon active filters, and should be designed to remove any oil droplets present in the gas stream. The gas will be dried by passing through the molecular sieve dehydration package. In the next stages, “ethylene distributor” column which separates methane from ethane in the presence of hydrogen is utilized, while ethylene is distributing between the overhead and bottoms products. The ethylene distributer column overhead is processed in a downstream de-methanizer column, and the ethylene distributor bottom is processed in a downstream C2 splitter column. The pure Ethylene from top of the C2 Splitter and from bottom of the De-methanizer will mix to create the on-spec recovered product.

Membrane:

The purge gas stream, typically pressurized and containing the ethylene monomer and disturbing inert gas, is fed into the membrane system, while the permeate side of the membrane separation stage is fed back to the existing process gas compressor’s suction side. By means of the resulting pressure difference and the hydrocarbon selective membrane material, the purge gas stream is separated into the inert gas enriched off gas and the recycled ethylene-rich permeate stream. Typically no other equipment or machinery is required, which results in a very simple and reliable process solution.

Waste Water Treatment - Clarification

Clarification occurs in a large basin where water is again allowed to flow very slowly. Sludge, a residue of solids and water, accumulates at the basin's bottom and is pumped or scraped out for eventual disposal. Clarification is also sometimes called sedimentation.

Steps of Clarification

  • Coagulation. Coagulation can be accomplished through the addition of inorganic salts of aluminum or iron. These inorganic salts neutralize the charge on the particles causing raw water turbidity, and also hydrolyze to form insoluble precipitates, which entrap particles. Coagulation can also be effected by the addition of water-soluble organic polymers with numerous ionized sites for particle charge neutralization. 
  • Flocculation. Flocculation, the agglomeration of destabilized particles into large particles, can be enhanced by the addition of high-molecular-weight, water-soluble organic polymers. These polymers increase floc size by charged site binding and by molecular bridging.

Horizontal Flow Clarifiers, Originally, conventional clarification units consisted of large, rectangular, concrete basins divided into two or three sections. Each stage of the clarification process occurred in a single section of the basin. Water movement was horizontal with plug flow through these systems.

Upflow Clarifiers, Compact and relatively economical, upflow clarifiers provide coagulation, flocculation, and sedimentation in a single (usually circular) steel or concrete tank.

In-Line Clarification is the process of removing raw water turbidity through the addition of coagulant just prior to filtration.

Flue Gas Desulphurization

NORDEN FGD (Flue Gas Desulphurization) plants are based on the wet limestone technology with production of gypsum, which is readily usable by manufacturers of gypsum based products.

The limestone wet process has become the most popular process for flue gas desulphurization; NORDEN has the experience and the know-how for the design and the construction of complete FGD plant, with main characteristics as follow: 1- High removal efficiency (> 96%), 2-Limestone consumption closely approximating stoichiometric requirements, 3- Reduced space requirements due to compact construction, 4- Scrubbing tower complete with integral absorption, oxidation, crystallizing and mist separation stages, 5- Low residual moisture in effluent gas by optimal location of the demister, 6- High gypsum purity in the final product as a result of high oxidation efficiency

PROCESS DESCRIPTION

Flue gas ducts connect flue gas system to absorber and from absorber to stack. After the flue gas cleaning a reheating system for clean gases is required before they enter the stack.

The absorber consists of a vertical cylindrical vessel, with a flue gas inlet and outlet opening. The part of the absorber between the gas inlet and gas outlet (the gas section) may be subdivided in "the spray section" and in "the mist eliminator section". The part of the absorber below the gas inlet contains the absorber slurry (the sump). In the spray section, the flue gas will be in contact with a fine spray of limestone slurry droplets, as produced by the slurry spray banks, equipped with spray nozzles.

The SO2 and other acid gases are absorbed to a large extend in the slurry droplets and react with the limestone present in the slurry to form gypsum. In order to obtain nearly 100% oxidation of sulphite to sulphate, the absorber is provided with an oxidation air injection system for the injection of a certain flow of oxidation air, supplied from a compressor system.

The bleed system consists essentially of an absorber bleed pump and a gypsum cyclone battery, supplied with absorber slurry by the absorber bleed pump.

The underflow of the cyclones flows to the mechanical dewatering that produces dry commercial gypsum with a maximum water content of 10%.

Waste Water Treatment - Filtration

NORDEN will design, manufacture and install filters for waste water treatment systems; Filtration is used in addition to regular coagulation and sedimentation for removal of solids from surface water or wastewater. This prepares the water for use as potable, boiler, or cooling make-up. Wastewater filtration helps users meet more stringent effluent discharge permit requirements. below are major methods we use:

MIXED MEDIA FILTER BEDS apply to a type of filter bed which is graded by size and density.

GRAVITY FILTERS are open vessels that depend on system gravity head for operation. The essential components of a gravity filter include The filter shell, The support bed, An underdrain system, Wash water troughs and Control devices that maximize filter operation efficiency. 

PRESSURE FILTERS are typically used with hot process softeners to permit high-temperature operation and to prevent heat loss. The use of pressure filters eliminates the need for repumping of filtered water. Pressure filters are similar to gravity filters in that they include filter media, supporting bed, underdrain system, and control device; however, the filter shell has no wash water troughs.

PRECOAT FILTRATION is used to remove very small particulate matter, oil particles, and even bacteria from water. This method is practical only for relatively small quantities of water which contain low concentrations of contaminants.

Denox Process

The most effective process to date for flue gas NOx removal in power plants is known as selective catalytic reduction (SCR). It operates at temperatures of between 300 °C and 400°C on the reaction principle that is  summarized by the following equations: 

Before the flue gas enters the reactor, ammonia is added in the form of a NH3 / air mixture, which promotes the reduction of nitrogen oxides when the gas comes into contact with the catalyst.
The DENOX unit can be installed downstream of the boiler between the economizer (feed water pre-heater) and the combustion air preheater and is known as the “high-dust” configuration.
When the unit is located downstream of the electrostatic precipitator this result is the so-called “low-dust” configuration. In this configuration the DENOX unit may be also installed downstream of the desulphurization system. This result is the so-called “tail-end” configuration.

THE DESIGN

Taking into account the Customer specifications and the amount of space available in each case, the size of individual reactors is optimized with the aid of pilot plant tests and with computational fluid dynamic models. The criteria of particular importance include the thorough mixture of NH3 and NOx molecules in the reactor hood and a constant gas flow in the vertical part of the reactor.
The key design parameter in a reactor of this type is the so-called space velocity (is normally between 1000 and 3000 per hour whereas for oil – and gas). This is a measure of the residence time of the flue gas mixture within the catalyst volume and result in a smaller quantity of catalyst being required for the NOx reduction.
Calculation of the space velocity takes into account the following factors:

  • Efficiency of the DENOX reaction
  • Temperature
  • Allowable ammonia slip
  • Flue gas analysis
  • Dust analysis
Waste Water Treatment - Softening

Softening:

When water contains a significant amount of calcium and magnesium, it is called hard water. Hard water is known to clog pipes and to complicate soap and detergent dissolving in water.
NORDEN Water softening technology is a technique that serves the removal of the ions that cause the water to be hard, in most cases calcium and magnesium ions. Iron ions may also be removed during softening.

 Water softeners are specific ion exchangers that are designed to remove ions, which are positively charged.
Softeners mainly remove calcium (Ca2+) and magnesium (Mg2+) ions.

Softeners have different types such as automatic, semi-automatic, or manual.

A water softener typically consists of two tanks, a larger one into which rock or pellet salt is added and a smaller tank containing the ion exchange resin through which the hard water passes.

After water softening bed regeneration is initiated, the first step is to backwash the resin bed. Then brine is slowly deducted from the salt tank at a set flowrate for a specific time.

Given proper consideration of raw water quality and ultimate end use of the treated water, the application of precipitation processes has few limitations. However, operational difficulties may be encountered unless the following factors are controlled: Temperature, Hydraulics, Chemical Control.

 

Refrigeration

Generally, refrigeration is used for liquify gases. Refrigeration process consists of five component equipment, which are as follow:

1. Compressor; which compresses the vapor to a higher temperature and pressure. 

2. Evaporator; in which two phase fluid formed in the expansion step is sent to a heat exchanger with low pressure and temperature then the cold refrigerant and the warm process gas exchange heat.

3. Condenser; The high pressure superheated vapor from the compressor is then cooled and condensed at a relatively constant pressure. The cooling medium in the condenser is usually water, air, and another refrigerant depending on the condensation pressure required.

4. Expansion Valve; which Liquid refrigerant is flashed across a control valve or other device to a lower temperature and pressure become two phases.

5. and Refrigerant

REFRIGERATING GROUPS

The most widely used design, all proposed by NORDEN are:

1. Mechanical Refrigeration.

2. Steam Jet Refrigeration.

3. Absorption Refrigeration.

All of the methods are using similar process to produce refrigeration effect: Evaporation, Condensation, and Expansion. The difference between them is in the way compression is done to the refrigerant.

 

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