Phase-change heat exchangers

Phase-change heat exchangers

Phase-change heat exchangers is to heating up or cooling down fluids in just a single phase, heat exchangers can be used either to heat a liquid to evaporate (or boil) it or used as condensor to cool a vapor  and condense  it to a liquid. In chemical plants  and refineries ,reboilers  used to heat incoming feed for distillation  towers are often heat exchangers.

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SETUP For Phase-change heat exchangers  :

Distillation set-ups typically use condensers to condense distillate vapors back into liquid.

Power plants that use steam -driven turbines commonly use heat exchangers to boil water into steam. Heat exchangers or similar units for producing steam from water are often called boilers or steam generators.

Phase-change heat exchangers For USES:

In the nuclear power plants called pressurized water reactors , special large heat exchangers pass heat from the primary (reactor plant) system to the secondary (steam plant) system, producing steam from water in the process. These are called steam generators. All fossil-fueled and nuclear power plants using steam-driven turbines have surface condensers to convert the exhaust steam from the turbines into condensate (water) for re-use.

To conserve energy and cooling capacity  in chemical and other plants, regenerative heat exchangers can transfer heat from a stream that must be cooled to another stream that must be heated, such as distillate cooling and reboiler feed pre-heating.

This term can also refer to heat exchangers that contain a material within their structure that has a change of phase. This is usually a solid to liquid phase due to the small volume difference between these states. This change of phase effectively acts as a buffer because it occurs at a constant temperature but still allows for the heat exchanger to accept additional heat. One example where this has been investigated is for use in high power aircraft electronics.

Heat exchangers functioning in multiphase flow regimes may be subject to the Ledinegg instability.

Plume abated cooling towers

Plume abated cooling towers

Plume abated cooling towers

 OVERVIEW for Plume abated cooling towers

Plume from a cooling tower can pose several issues. It may affect visibility and safety as well as public perception.

Plume abatement is the process of removing this visible plume.

ClearSky is a fully integrated system that operates more reliably than coil-based systems. By using a series of PVC heat exchanger modules in the tower plenum, ambient air condenses much of the moisture before it exits the tower thereby reducing the plume.

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Aesthetics / Neighbor Relations
Even though the cooling tower plume is made up of water vapor, a community may perceive it as unwanted or smoke-related. This may affect the use of nearby land or decrease property values.


Community concerns regarding visibility can be removed by significantly reducing visible plume.


The ClearSky Plume Abatement System can be added to existing cooling towers in many cases, making plume abatement even more economical.


Permitting can be a long and costly process. Eliminating the visible plume may enhance a smooth permitting process.


Water is increasingly becoming a scarce and valuable commodity. Removing water from the vapor plume can help decrease water-related costs and help the environment.

Benefits include:

Lower Installation Cost—Less piping means less investment than conventional systems

Greater Design Flexibility—Back-to-back design allows for easy installation, including retrofits

Reduced Maintenance Costs—Unique patented design and materials means less need for maintenance

Reduced Auxiliary Power Usage—Driven by reduced pump head, ClearSky towers can effectively reduce auxiliary power usage when compared to coil type hybrid towers

Improved Permitting—Smoother process with reduced likelihood of interruption due to public comment

Lower Cost Versus Dry—The high-performance operation you need with fewer costs

Utilizes less energy and has lower carbon footprint, than dry systems

Improved safety for surrounding transportation and improved neighbor relations

U Tube Bundle

U Tube Bundle


U tubes can duplicate any existing bundle to include dimensions, materials and performance.

A heat-exchanger system consisting of a bundle of U tubes hairpin tubes surrounded by a shell outer vessel. one fluid flows through the tubes, and the other fluid flows through the shell, around the tubes.

One of the most common applications is the cooling of Hydraulic Fluid and oil in engines, transmissions and hydraulic power packs.

With the right choice of materials they can also be used to cool or heat other mediums, such as swimming pool water or charge air.

There are often baffles directing flow through the shell side so the fluid does not take a short cut through the shell side leaving ineffective low flow volumes. These are generally attached to the tube bundle rather than the shell in order that the bundle is still removable for maintenance. Counter current heat exchangers are most efficient because they allow the highest log mean temperature difference between the hot and cold streams. Many companies however do not use single pass heat exchangers because they can break easily in addition to being more expensive to build. Often multiple heat exchangers can be used to simulate the counter current flow of a single large exchanger.

Specifications :

  • The simple design of a shell and tube heat exchanger makes it an ideal cooling solution for a wide variety of applications.

Applications :

  • One of the most common applications is the cooling of Hydraulic Fluid and oil in engines, transmissions and hydraulic power packs.
  • With the right choice of materials they can also be used to cool or heat other mediums, such as swimming pool water or charge air.


Advantages :

  • One of the big advantages of using a shell and tube heat exchanger is that they are often easy to service, particularly with models where a floating tube bundle (where the tube plates are not welded to the outer shell) is available. Can also be used on fixed tube sheet heat exchangers.


Ammonia Chillers

Ammonia Chillers

Ammonia Chillers

Gireesh Ammonia Chillers, Chilling Plant are compact and skid mounted and are usable for a wide temperature range from medium to low temperature process cooling applications, like in pharmaceutical, chemical, dairy, food processing, beverages, cold storage, ice making, industrial gases as well as medium temperature application like HVAC, Plastics, Concrete cooling etc.

Complete study of the process to ascertain peculiarity of the requirement, precedes the choice of equipment and accessories being proposed, through an engineering team with specific expertise.


Prominent features

  • Highly reliable screw and reciprocating compressors from Europe, Japan and US
  • Natural refrigerant NH3 with zero ODP and zero GWP, with the highest energy efficiency
  • Widest operating temperature range, (+) 30oC to (-) 40oC
  • Customized as per the extreme and sensitive environmental conditions, factory inspected and certified
  • Factory assembled and tested equipment with the option to dismantle and re-commission at site, in case of very large sizes
  • Factory made and tested Flooded evaporators, made as per highest international standards of manufacturing
  • High fouling factors, increased condensing area, extra tube thickness and high-flow design, for highest energy efficiency, higher operational reliability and easier maintenance
  • Stepped and stepless capacity control, from 25% to 100%, adapting precisely to varying process loads
  • Fully automatic PLC based units with remote operation and data logging facilities
  • Customized turnkey cooling solutions available

Ammonia Refrigeration Safety

The risks involved with ammonia refrigeration can be reduced substantially by careful management and maintenance. Part of that process is clear labeling of the pipes and equipment being used. As the accepted industry experts in this field, the IIAR maintains a code of recommendations for refrigeration equipment labeling.

There are five elements in a typical ammonia pipe marker:

  • Piping abbreviation, such as “LTRS” for Low Temperature Recirculated Liquid, to identify the part of the system that the pipe represents
  • Physical state of the pipe’s contents, shown with letters on a colored band: “LIQ” on yellow, for liquid; “VAP” on sky blue, for vapor; or both, if the pipe could contain both phases
  • Pipe contents, simply and clearly indicated with the word “Ammonia”
  • Pressure level, shown with letters on a colored band: “LOW” on green, for contents at 70 psig or less; or “HIGH” on red, for contents above 70 psig
  • Flow direction, indicated with an arrow pointing along the pipe in the correct direction

Transformer Oil Cooler

Transformer Oil Cooler

Transformer Oil Cooler

Transformer oil coolers play a critical role in keeping electrical generation systems reliable. Transformer oil coolers are a small investment that protect the power industry’s huge capital investment in the massive transformers that make up the backbone of a nation’s energy supply.

Power plant generators produce electricity that has to be converted to high voltage for more efficient transportation across wires to substations near businesses, factories and homes. The transformers that convert the electricity to high voltage do so extremely efficiently with only something in the order of 0.5 percent of the electrical load being lost in the form of heat. Even though the loss percentage is small, the actual quantity of heat can be quite large. The heat that is produced must be carried away from the transformer and dissipated. If not, the transformer will overheat and be damaged or even destroyed.

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Several other site-specific factors must be taken into account to avoid detrimental affects on cooler performance:

  • Wind speed and direction can be a factor–for example if fans are blowing air away from the transformer but the prevailing wind is blowing towards the transformer, warm air will be pushed back.
  • Buildings around the transformer, firewalls or other fire protection components can trap air and impede air exhaust.
  • Existing transformer cooler applications elsewhere on the site could blow heated air toward the new installation.

For example, a designer may be asked to design a system based on a 30 Celsius (°C) ambient situation. However, due to one or more of the factors described above, the air immediately adjacent to the transformer might not be 30 °C, but could possibly be as high as 35 °C to 50 °C. Experienced designers know to design a system that reflects these actual ambient conditions.


Gas Liquefaction Chillers

Gas Liquefaction Chillers

Gas Liquefaction Chillers

Gireesh design, manufactures, supply, install and commission Freon / Ammonia based Gas Liquefaction Plants required for liquefaction of gas like Carbon Dioxide.

Gireesh has successfully installed equipment for Carbon Dioxide Liquefaction, with environment friendly Refrigerant (R-404a) operating at (-) 30 Deg C Evaporating Temperature & 50 Deg C Condensing Temperature.

The equipments can be tailored to individual requirement.

We provide equipment for Carbon dioxide (CO2), Nitrogen (N2), Oxygen (O2).

Specification of Gas Liquefaction Chillers : –

As a noteworthy entity of this domain, we have been able to manufacture and supplier huge range of this product which is widely appreciated in the market. Gireesh  Gas Liquefaction Chillers are specially designed for the liquefaction of Industrial gases CO2, N2O etc. These chillers are completely skid mounted which include gas liquefying evaporators also. The chillers work on multiple refrigerants as per the process requirements. Customers can avail these products from us at reasonable prices.

Gireesh systems India ltd. Mumbai designs and manufactures refrigerated Gas Liquefaction Units and refrigerated vapor recovery units. We manufacture chlorine liquifies, acetone liquifies, oxide liquifies, co2 liquifies, ammonia liquifies, sulphur dia oxide liquifies. We also manufacture refrigeration plants for chlorine vapor recovery, acetone vapor recovery, oxide vapour recovery, co2 recovery, ammonia vapor recovery, sulphur dia oxide vapor recovery, hydrogen recovery, propane recovery, methane recovery, lng recovery, LPG recovery and many more.

Applications for Gas Liquefaction Chillers : –
  • Chemical plants
  • Steel plants
  • Machinery and parts companies

Gireesh Compressors can handle a wide range of petrochemical industry gases including hydrogen, helium, carbon dioxide; raw material gases including vinyl chloride, methyl chloride; active gases including chlorine, hydrogen chloride, hydrogen sulfide; gas mixtures and VOC and associated gases from refinery processes. Gireesh  gas compressors’ performance and reliability have been proven over and over in petrochemical, oil and gas projects around the world. Our gas compressors are applied to various fuel gases for power generation and recovering oil, hydrocarbons and raw material gases contributing to energy-saving and environmental sustainability.



Hazardous Area Chillers

Hazardous Area Chillers

Hazardous Area Chillers

Gireesh Hazardous Area Chillers are customized as per the specific process needs at various hazardous areas, certified through prestigious international certifying bodies. These highly specialized chillers find their applications in oil and gas industry throughout the world.

Hazardous Area Chillers.Gireesh Hazardous Area Chillers are customized as per the specific process needs at various hazardous areas, certified through prestigious international certifying bodies. These highly specialized chillers find their applications in oil and gas industry throughout the world.

Prominent features : –We manufacture our products from three modern and equipped manufacturing facilities, one in Delhi NCR and two in Uttarakhand. We have installed over 6000 Chillers worldwide. We bring to the industry the latest innovations benefiting our customers, through energy efficiency, lowest equipment life-cycle costs as well as customisation as per the specific process needs.

  • ATEX certified chillers, with UL / CSA / IECEx Certifications available
  • Designed for hazardous area classifications Zone-1 & Zone-2
  • Explosion proof designs for gas groups IIA, IIB and IIC
  • Using smart transmitters with all signal and control cables as per hazardous area Classifications
  • NEMA Standard enclosures for electrical control, junction boxes and motors
  • Special metallurgy equipment and accessories as per hazardous area classifications
  • Skid mounted designs, upto 1800TR nominal capacities
  • Microprocessor controlled with remote monitoring and data logging
  • Customized turnkey jobs handled

For Operation in Hazardous (Electrically Classified) Locations :

Cold Shot Chillers explosion proof process chillers are designed for operation in Electrically Classified locations – areas where combustible gasses or dusts may be present. Systems are available to satisfy either (North American) National Electric Code (NEC) and UL Standards or IEC (60079 series) Standards.

Systems are available for virtually any Area Classification – Zone 1 / Division One, Zone 2 / Division Two, for most Gas or Dust Groups and Temperature Codes. Please contact our Sales Group for a proposal.

Some of the available options include:

  • Redundant systems with Lead / Lag controls
  • Stainless Steel housings
  • Coil Coating wit extended warranty for air cooled units in corrosive areas
  • Disconnect Switches
  • Temperature Alarms
  • High or Low Ambient Rated Condensing Section
  • 50 or 60 Hz. power supply
  • Rotolock compressor connections to allow compressor change-outs without a flame

Flue Gas Air Pre Heater

Flue Gas Air Pre Heater
Flue Gas Air Pre Heater 

An air preheater (APH) is a general term to describe any device designed to heat air before another process (for example, combustion in a boiler) with the primary objective of increasing the thermal efficiency of the process. They may be used alone or to replace a recuperative heat system or to replace a steam coil.

In particular, this article describes the combustion air preheaters used in large boilers found in thermal power stations producing electric power from e.g. fossil fuels, biomasses or waste.

The purpose of the air preheater is to recover the heat from the boiler flue gas which increases the thermal efficiency of the boiler by reducing the useful heat lost in the flue gas. As a consequence, the flue gases are also sent to the flue gas stack (or chimney) at a lower temperature, allowing simplified design of the ducting and the flue gas stack. It also allows control over the temperature of gases leaving the stack.

  Types of  Flue Gas Air Pre Heater :-

There are two types of air preheaters for use in steam generators in thermal power stations: One is a tubular type built into the boiler flue gas ducting, and the other is a regenerative air preheater.These may be arranged so the gas flows horizontally or vertically across the axis of rotation.

Another type of air preheater is the regenerator used in iron or glass manufacture.

 Flue Gas Air Pre Heater  for Specifications :

The total air heated in the RAPH provides: heating air to remove the moisture from the pulverised coal dust, carrier air for transporting the pulverised coal to the boiler burners and the primary air for combustion.

Applications Flue Gas Air Pre Heater :

It rotates quite slowly around 3-5 RPM to allow optimum heat transfer first from the hot exhaust gases to the element, then as it rotates, from the element to the cooler air in the other sectors.

Advantages for Flue Gas Air Pre Heater   :

Air pre-heater transfer heat from flue gas to air by means of a rotary matrix in which heat is absorbed by the heating elements passing through the hot gas stream and transferred to the combustion air stream.

Copper Heat Exchanger

copper heat exchangers

Copper Heat Exchanger

Copper heat exchangers are more efficient than shell and tube exchangers for low flow rates. Due to their simple construction they are low in price and easy to clean on the shell side.

These copper heat exchanger tubes are normally supplied in straight length in annealed & half hard temper. Copper tubes are artificial to special requirements as to dimensional tolerances, finish and tempers for use in condensers and heat exchangers.

The copper tubes shaped by are metal industries not only have the stiff tolerances but also have the most dependable dimensions throughout the tube length. The tube surface is clean both inside and outside with no caustic stains.

The copper tubes produced by are metal industries are suitable to transfer heat in a wide variety of operating conditions and to refuse to accept decay for the longest period of time possible under the harshest operating circumstances.

Coils are made in different diameters using tubes of different bores.

Their thermal efficiency approximates that of a true countercurrent flow type exchanger. Condenserors are used for condensation of vapours and cooling of liquids. Condensers are made by fusing number of parallel coils in a glass shell.

Copper Heat Exchanger offered comprises quality micro unit heat exchange tube with optimum internal and external wall finish so as to offer optimum functional usage. Further, its spiral ripple construction helps in maintaining original flow state when fluid flows through external and internal tube walls.

Convoluted Copper Heat Exchanger

25 ft of 5/8″ convoluted copper.

9″ OD coil.

1/2″ FPT copper inlet and outlet.

Approximately 24″ in height to the bend for inlet and outlet.

Coils are approximately 9″ in height.

Some of its features include:

  • Double reinforcement finish
  • Reduce heat resistance while improving internal and external heat transfer coefficient
  • All tubes are bright annealing that guarantee smooth surface of the tube
  • All tubes coming inspected by Eddy-current test and hydraulic test to assure of consistent performance

Plate Fin Heat Exchanger

Plate Fin Heat Exchanger

Our aluminium plate-fin heat exchangers (PFHEs) are key components in many process plants. Their compact footprint helps save space and costs in a wide range of facilities, including air separation plants, petrochemical and gas treatment plants as well as natural gas and helium liquefaction plants.

Our PFHEs are brazed in vacuum furnaces without using flux. This means that all cores are delivered completely free from corrosive residue and post-brazing cleaning steps are not required.


Highlights of our PFHEs:

  • Tailor-made design
  • Proven vacuum brazing technology
  • High thermal efficiency through variable fin configurations
  • Aluminium alloys for optimum heat exchange between clean gases and liquids at low temperatures
  • Simultaneous heat exchange between multiple streams
  • Suitable for single-phase and mixed-phase fluids
  • Arrangement of streams in counter-flow, cross-flow or flow combinations
  • Wide range of fin types with different surface areas for optimised equipment design
  • Superior computer software for thermal and hydraulic design

ALPEMA For Plate Fin Heat Exchanger : –

Linde Engineering is also one of the founding members of the Aluminium Plate-Fin Heat Exchanger Manufacturers Association (ALPEMA).

The cost of plate-fin heat exchangers is generally higher than conventional heat exchangers due to a higher level of detail required during manufacture. However, these costs can often be outweighed by the cost saving produced by the added heat transfer.

Plate-fin heat exchangers are generally applied in industries where the fluids have little chances of fouling. The delicate design as well as the thin channels in the plate-fin heat exchanger make cleaning difficult or impossible.

Flow arrangement for Plate Fin Heat Exchangers  : –

In a plate-fin heat exchanger, the fins are easily able to be rearranged. This allows for the two fluids to result in crossflow, counterflow, cross-counterflow or parallel flow. If the fins are designed well, the plate-fin heat exchanger can work in perfect countercurrent arrangement