Heat exchangers are devices used to transfer heat from source to another source. For shell and tube heat exchangers, fluids of different temperatures flow through the exchanger.  One of the fluids flows through the tube bundle while another flows through the shell. Heat then transfers from one fluid to the other through either the tube side or the shell side of the exchanger. Heat exchangers and tube bundles can be made from a wide variety of available materials.

Commercial Coils offers both straight tube bundles and u-tube bundles.  Our heat exchangers and tube bundles are well tested and meet ASME codes to ensure quality performance. We have a large OEM cross reference library including manufacturers such as Armstrong, Basco, and Bell & Gossett.

The tube bundle is made of parallel tubes disposed in circular configuration in which the combustion air flows inside. The tubes are connected at their and with two annular air collectors (upper and lower) where the air is blown from the main combustion fans and then delivered to the burners. The inner side of tube is provided with air swirling system that enhance the turbulence and heat exchange capabilities.

The hot waste gases flow in the centre of the tube assembly in parallel with the air. The entire tube bundle is installed within the external casing which is insulated by a thick layer of insulating material. The expansion can be upward with spring system or downward by gravity, in function of overall size of recuperator and other engineering characteristics.

The tube bundle and the air boxes are realized in high alloyed stainless steel of different grade in function of max operating temperature while the external casing is made in standard carbon steel. The refractory materials are selected according to working conditions and fumes characteristics.

Depending on configuration (single stage or double stage) these recuperators can preheat air in a range between 700°C up to 850°C.

The main features are:

Up to 850°C in double stage configuration, High alloyed stainless steel construction, Extended lifespan, High reliability, Easy maintenance

One fluid runs through the tubes, and another fluid flows over the tubes (through the shell) to transfer heat between the two fluids. The set of tubes is called a tube bundle, and may be composed of several types of tubes: plain, longitudinally finned, etc.

Tube bundles are available in a wide variety of designs and materials of construction. In-house bending equipment assures high quality and fast turnaround.

Features:

3/8 ” to 1-1/4″ in OD tube in stock

Smooth, Integral and Applied fin tubes

Straight or “U” Tube designs

Titanium, 316ss, 304ss, Cupronickel and other Nickel Alloys

Single Groove, Double Groove and Seal Weld capabilities

Turn around for new and replacement order faster than the OEM

Fast Turn-Around

Emergency Service

Tube bundle heat exchangers are primarily suited for heat transfer between various liquids and gases with or without phase change. Excellent results have been obtained using water, thermal oil, wet steam etc. to warm or cool liquids and gases. The standard series consists of 6 sizes with heat transfer surfaces ranging from 0.5 to 500 m2.

Range of application

Tube bundle heat exchangers have a great versatility in their use and are applied in different branches of the industry, e.g.: Power station technics, Machine industry, Gear manufacturing, Chemical Industry, Process engineering

Design and Function

The heat exchangers consist basically of housing and tube bundle. The housing is a welded construction and includes all connecting, joining and fastening elements. The standard smooth tube bundle to be installed is a two-way model. The exchanger design variation with U-tubes (U-design), the variation with the floating tube base (D-design) or with a fix compensator (K-design) all of them allow for large changes in length between the casing and the tube bundle due to heat expansion.

Materials

The following material combinations are possible (special materials on request):

Casing tube: Steel St37-2, St37-2 galvanised, stainless steel V2A/V4A

Lid: Steel St37-2, St37-2 coated with RILSAN, stainless steel V2A/V4A

Cooling tubes: SF-CU, CuZn20Al, CuNi10Fe, CuNi30Fe, stainless steel V2A/V4A

Type G: Tube bundle heat exchanger

Universal tube bundle heat exchanger for liquids and gases. Depending on the requirements different materials up to maximum quality stainless steels with high corrosion resistance are used. Also operation over-pressures up to 800 bar are possible. The standard series include 6 sizes with transfer surfaces up to 150m2.

Type GK: Tube bundle condenser

GK types are used to heat up liquid or gaseous medium by means of condensation of wet steam, overheated steam or cooling agent. Depending on the application the steam is leaded on the tube side or on the shell side. Different constructions in horizontal or vertical position with transfer capacities up to 20MW are available.

Type GV: Tube bundle evaporator

The GV type is used for cooling of liquids by means of evaporation of cooling agent, especially also ammonia. This series include horizontal and vertical constructions with removable or fixed welded tube bundles.

Type GD: Steam generation plant

The GD series are used for the indirect production of low- or high-pressure steam. They are heated with steam, hot water or thermal oil. These usually horizontal position types are, depending on pressure and contents, produced with the corresponding test certificates.

Type GA: Exhaust gas heat exchanger

For heat recovery of flue gas principally the GA type is used. The recovered heat of thermal combustion processes, of heat and power plants etc. will be delivered to hot water, thermal oil or for example to the combustion air. In special applications also the condensation heat of flue gases can be recovered.

Type GS: Safety heat exchanger

By using a double tube the risk of contact between the two media is eliminated. The space in between is filled with a sealing fluid which absorbs the heat expansion while monitoring the tightness of the tubes. Any leaks can be reported immediately.

Design and fabrication capabilities include:

New and Replacement Units with ASME Section VII Division 1 requirements and TEMA B, C, and

R standards

4” Nominal to 60” Nominal

Shell and Tube type Units

Industrial type exchangers for Chemical, Food Process and other industries.

Aftercoolers, Oil Coolers, Suction Heaters, Tank heater and Fixed Tubesheet type Units.

Standard design for complete exchangers is ASME Section VII Div. 1 TEMA C for 150 psig at

375°F. Other designs available upon request.

We manufacture heat exchanger with both removable and fixed U tube bundle; this configuration allows the tubes to expand independently from the shell, particularly indicated for a high temperature fluid and in case of steam.

Since fluid in tube side can flow without obstacles, this configuration is indicated also for low pressure drop need. All materials available: carbon steel, stainless steel or non-ferrous materials according to the needing.

The fixed tubebundle is the basic configuration, strong and efficient, available in many different materials to satisfy any combination of fluids and flows.

Tube Bundle Exchangers used fields, Chemical, Energy, Marine, Petrochemical Industry.

Types: Fixed tube bundle systems. Removable tube bundle systems U bend type. Removable tube bundle systems floating tubesheet type. Bare tubes. Low finned tubes. Finned tubes. Internally grooved tubes.

Range of Production: Pressure: up to 550 bar. Temperature: up to 600 °C. Max Length /diameter : 18 m / 3 m.

Standard materials: Carbon steel and its alloys. Stainless steel. Copper and its alloys. Nickel alloys. Titanium. Aluminium.

Our tubular bundle drier of the RK series is an indirectly heated contact drier. It has especially been designed for free flowing materials like malt spent grains, maize germs, maize hulls, maize gluten and maize flour, crushed soybeans, crushed rape seeds and grapeseeds, mineral granulates, sesame, rice flour and sunflower seeds.

Technical Data

heated by steam, 140 bis 210 °C steam inlet temperature, 3000 to 3360 kJ thermal energy consumption per kg evaporated water, 25 up to 2500 m² heating surface, 3 to 6 kg/m²h specific drying rate, inspection openings, mounted on a sturdy supporting frame, certified by TÜV (German Association for Technical Inspection)

Options

wide choice of weldable construction materials, e.g. 1.4301 or 1.4571

two tubular bundles paired into a single housing

instrumentation and control system for an almost automated drying process

complete insulation for outside installation