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"INTECH GmbH"
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Distributor / authorized representative that deals with supply & delivery of heat exchangers to industrial enterprises of Russia

Engineering company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), Russia, has been successfully working with a number of Russian industrial enterprises at the local market for more than 20 years. Since the company’s founding, it has acquired immense engineering experience, market reputation, and has realized more than a hundred large-scale projects at the industrial plants in Russia. Our company is continuously in search of new business partners, who consider Russian market investment-attractive and want to boost their sales in the region, as well as expand their field of activities and enter a new international level.

We are interested in cooperation with the manufacturers of heat exchangers, who are looking for an official and reliable distributor that deals with supply & delivery of their equipment to the industrial plants in Russia.

The company’s top management and sales team are well acquainted with the Russian market, its mentality and laws; they also understand industrial specifics of the financial and economic activities of the Russian customers. All our sales managers have a large customer database, extensive experience of successful sales and well-established connections with the potential buyers of your heat exchangers. This allows our managers to promptly set out the most promising directions for promotion and to ensure a rapid entry of the products into the promising Russian market. Our employees, who are fluent in English and German, are focused on working at the international market with the supplies of foreign equipment.

Our team of experienced engineers, who can handle the most serious technical problems, constantly keeps in touch with the Russian customers, holds meetings and delivers presentations regarding the latest achievements of our manufacturing partners. They point out the engineering challenges and actively communicate with all the departments at Russian plants. That is why the specifics of doing a business in the Russian Federation are well-known to us, and we also know the equipment of the local industrial plants and their up-to-date modernization needs.

Once we become your authorized representative in Russia, our marketing staff will carry out a market research in order to check the demand for heat exchangers, will submit a market overview for heat exchangers that you offer and evaluate the needs for this type of equipment at local plants. Our specialists will also estimate the potential and capacity of this market at local industrial plants. Our IT-team will start developing a website for your products in Russian. Our experts will assess the conformity between your heat exchangers and customer needs as well as analyze the common reaction to the new goods in general. We will look into the categories of potential customers, and pick out the largest and the most promising plants.

Upon becoming your authorized agent on the territory of Russia, ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), will obtain certificates, if required, for a batch of the goods, for various types of heat exchangers in compliance with Russian standards. We can also arrange the inspection in order to obtain TR TS 010 and TR TS 012 Certificates. These certificates provides permission to operate your equipment at all industrial plants of the EAEU countries (Russia, Kazakhstan, Belarus, Armenia, Kyrgyzstan), including the hazardous industrial facilities. Our company is eager to assist in issuing Technical Passports for heat exchangers as per Russian and other EAEU countries’ requirements.

Our engineering company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), collaborates with several Russian design institutes in various industrial segments, which allows us to conduct preliminary design as well as subsequent design works according to the standards, construction rules and regulations that are applicable in Russia and other CIS countries. It also enables us to include your heat exchangers into the future projects.

The Company has its own logistics department that can provide packing service, handling as well as the most efficient and cost effective mode of transportation of the goods (incl. over dimensional and overweight goods). The goods can be delivered on DAP or DDP-customer’s warehouse basis in full compliance with all the relevant regulations and requirements that are applicable on the Russian market.

Our company has its own certified specialists who will carry out installation supervision and commissioning of the delivered equipment, as well as further guarantee and post-guarantee maintenance of heat exchangers. They will also provide necessary training and guidance for the customer’s personnel.

Brief overview of heat exchangers

Heat exchangers are devices transferring heat from media to media, i.e. from hot heat transfer streams to cold ones. There is a variety of heat exchangers; they are classified depending on functional and design-related characteristics and heat transfer mode. Heat exchangers are widely used in chemical industry where they are applied in the following processes:

  • heating and cooling of substances in various states of matter;
  • evaporation of liquids and condensation of vapors;
  • distillation and sublimation;
  • absorption and adsorption;
  • solid body melting and crystallization;
  • heat removal and supply for implementation of particular reactions.

Heat exchange surface area. Heat transfer coefficient. Effectiveness of heat exchangers. Heat balance equation

The effectiveness of a heat exchanger is defined by the quantity of energy Q transferred by the device during the specified time. This value, in turn, depends on such parameters as: heat permeability coefficient, k; heat exchange surface area, A; and average temperature difference, Δtm.

Q=k·A·Δtm

The heat permeability coefficient k depends directly on the design of a heat exchanger, the type of material used to make a device and specific features of substance flows in a heat exchanger.

k=[(1/α1)+(s/λ)+(1/α2)]-1

Scale, salt crust and other deposits formed on tubes negatively affect the heat exchanger operation effectiveness. Due to that, deposits must be regularly removed and their formation must be prevented.

Heat transfer agents temperature difference as a driving force for heat exchange

The difference between temperatures of heat transfer streams (t1-t2) is a driving force for the heat exchange process. As a rule, the level of temperature of substance flows (or at least one of these flows) varies while these flows run on a heat exchange surface, resulting in variation of temperature difference from cross-section to cross-section: Δt=t1-t2. Thus, the heat transfer equation must be written for a general case in a differential form for a surface element dF/dQ=k·Δt·dF, where, for K=const

Q=k·∫0F(Δt·)dF=K·Δave·F

where Δave is the average difference between temperatures of heat transfer agents along the heat exchange surface.

The heat exchanger’s process design task is as follows:

  • to find necessary heat exchange surface F for given water equivalents (W1 and W2) and temperatures of both heat transfer agents (t'1, t"1, t'2, t"2);
  • or to find possible thermal flow Q in a device with the surface area F for given values of other characteristics.

In both cases, the average temperature difference must be known.

Thermal energy transfer modes

There are three fundamental modes of heat transfer from one heat transfer agent to another:

  1. Thermal conduction is transfer of thermal energy by collisions of oscillating microparticles.
  2. Radiation is energy transfer in the form of electromagnetic waves radiated by bodies.
  3. Convection takes place due to motion and mixing of particles of liquid or gas.

In different parts of heat exchangers, the heat exchange process can run differently and can combine all or several of aforementioned heat transfer modes. Therefore, for calculation purposes, the heat transfer process is considered as a single process.

Types of industrial heat transfer agents

Industrial heat transfer agents can be subdivided into the following major types:

  • water steam;
  • flue gases;
  • high-boiling industrial heat transfer agents (organic, ionic, liquid-metal);
  • inorganic agents.

Water steam is widely used at chemical industry enterprises. This heat transfer agent has high specific enthalpy (latent heat of evaporation under normal pressure is 2256.8 kJ/kg) and high heat emission coefficient during condensation. Heating by water steam becomes economically unreasonable if the temperatures to be reached are higher than 200°C. For high temperatures, water has similar disadvantages; moreover, its heat emission coefficient is worse than that for water steam.

When flue gas is used, high temperatures can be reached by burning of gaseous, liquid and solid fuels. The disadvantage of this type of heat transfer agent is its low heat emission level. As a result, large heating surfaces are necessary, making fine adjustment of temperature drop impossible.

For operation with temperatures higher than 200°C, high-boiling organic and inorganic heat transfer agents are used. The group of organic heat transfer agents includes cyclic, acyclic and combined compounds with boiling temperatures up to 380-420°C, aromatized mineral oils, cylinder and compressor mineral oils. In terms of heat emission coefficient, vapors of organic heat transfer agents are worse than those of water steam and are comparable with liquid heat transfer agents provided that the circulation speed is about 3-4 m/s.

Organic heat transfer agents are combustible and explosive but not aggressive against standard structural materials (except for chlorinated derivative compounds). The most widely used organic heat transfer agent in industry is the eutectic mixture of diphenyl and diphenyl ether (40% of plants).

Ionic heat transfer agents are used in liquid and vaporous state. Heat transfer agents of this type have high melting and boiling temperatures, so, their application in industry is limited. By their structure, ionic heat transfer agents are subdivided into two groups:

  • salts and their eutectic alloys;
  • organosilicon salts.

Now, aromatic ethers and orthosilicic acids are the most commonly used in industry.

The group of liquid-metal heat transfer agents includes metals and their alloys used in liquid and vaporous state (rarely). As these heat transfer agents have highest thermal resistance, they are characterized by higher aggressiveness against structural materials; therefore, maximum of temperatures of liquid-metal heat transfer agents is limited by their corrosive activity.

These heat transfer agents are toxic in their vaporous state, explosive when mixed with air, and prone to intensive oxidation at operating temperatures.

The choice of a heat transfer agent depends on the following factors:

  • required operating temperature;
  • density;
  • viscosity;
  • specific heat capacity;
  • heat conductivity coefficient.

Heat transfer agent flow patterns

In practice, there are four patterns of heat transfer agent flow:

  • direct flow – parallel flow in the same direction;
  • counter flow – parallel flow in opposite directions;
  • cross flow – flow in perpendicular direction;
  • mixed flow – one or several heat transfer agents make several strokes in a device, flowing around a part of a surface in accordance with the direct flow pattern, and around other part,  in accordance with counter flow or cross flow pattern.

Heat transfer agent types

Heat exchange equipment is widely used in industry for heating and cooling of process flows. To heat a colder flow, a heat transfer agent called a heating agent is used. To cool a hotter flow, a heat transfer agent called a cooling agent is used.

Heating agents

A heating agent is an intermediate link in a heating process: it receives heat from immediate sources of thermal energy (flue gases and electric energy) and transfers it to the process flow. For heating of process flows in industrial heat exchangers, various gaseous and liquid heating agents are commonly used such as:

  • water steam;
  • hot water;
  • high-temperature liquids (organic and inorganic).

Water steam is most commonly used in industrial heat exchange processes. It has high heat emission coefficient during condensation and high specific heat capacity. Its fire and explosion safety and capability to control heating are also considered as its important advantages. The temperature of heating by steam is limited by ~ 200°C; this is due to significant pressure rise with temperature growth, resulting in need for more sophisticated and costly equipment. Water has similar disadvantages.

To implement heating within the range from 200 to 400°C, high-temperature liquids are used: these liquids include organic and inorganic substances. Organic heat transfer agents comprise such substances as glycerol, diphenyl mixtures, naphthalene and its derivatives, cylinder oils and mineral oils. The heat emission coefficient for organic compounds is lower than that for water steam. Organic compounds are not corrosive for structural materials. Combustibility and explosiveness are the disadvantages of these heat transfer agents.

As inorganic heat transfer agents, metals (predominantly in liquid state) and several salt melts are used. Metals have highest thermal resistance among heat transfer agents. High corrosive activity and toxicity of vapors are considered as their major disadvantages; therefore, their application is determined by resistance of structural materials.

Salt melts have high melting temperature, limiting their application in industry.

Flue gases are used for heating up to extremely high temperatures (1000°C). The disadvantages of this heat transfer agent include low heat emission coefficient and surface contamination by products of incomplete fuel combustion, thus leading respectively to enlargement of heat exchange surface and complication of temperature control.

Heating by electricity can be implemented in a wide range of temperatures with precise control, but it is economically disadvantageous due to its high cost.

The choice of a heat transfer agent is predefined by the specific conditions of the process to be carried out and, first of all, it depends on the required heating or cooling temperature and the necessity to control it. To implement the specified temperature mode and to ensure reliable operation, the heat transfer agent must meet several requirements:

  • High heat emission intensity must be provided;
  • Physico-chemical properties: low viscosity and high heat capacity, vaporization heat and density;
  • Low corrosiveness;
  • Non-toxicity;
  • Thermal resistance;
  • Economic characteristics: availability and not very high cost;
  • Fire and explosion safety.

Cooling agents

Cooling agents are used to remove excessive thermal energy from process flows and devices, depending on their application. For cooling down to temperatures ≈10-30°C, the most common and cheap heat transfer agents are used: water and air. If cooling down to lower temperatures is necessary, low-temperature liquids are used.

Cooling by water provides for usage of surface heat exchangers or, less often, mixing heat exchangers. If water cooling is used, the following aspects must be taken into consideration:

  • initial water temperature (for calculations, the highest summer temperature must be assumed);
  • final water temperature (at the heat exchanger outlet, water temperature must not exceed 50°C, because higher temperatures give rise to intensive water evaporation resulting in growth of flow rate and deposition of dissolved salts on a heat exchange surface).

Unlike water cooling, air cooling is used more often in mixing heat exchangers. First of all, this is due to the fact that air has low heat emission coefficient, and, as a result, significant increase of heat exchange surface and consumed air flow rate is required. Nevertheless, air cooling has several advantages contributing to the growth of service life of a device (no corrosive attack, no contamination of the heat exchange surface).

Cooling down to temperatures below 0°C is implemented by low-temperature fluids such as Freon, ammonia, carbon dioxide and cooling salt brines. For this purpose, special cooling plants are provided for, operating in a closed-cycle mode.

Heat exchanger types

Depending on their functionality, the following types of heat exchanges exist:

  • preheaters;
  • coolers;
  • evaporators;
  • condensers;
  • distillers;
  • sublimators;
  • melters etc.

Depending on the configuration type, the following types of heat exchangers exist:

  • heating/cooling jackets provided with a mixer;
  • tubular (including shell-and-tube heat exchangers);
  • tube-in-tube heat exchangers;
  • spiral-type;
  • plate-type;
  • plate-fin;
  • block graphite;
  • air coolers with finned tubes;
  • spray-type;
  • tower-type.

Types of heat exchangers depending on heat transfer method

Depending on the heat transfer method, the following types of heat exchange devices can be specified:

  • surface heat exchangers;
  • mixing heat exchangers.

In surface heat exchangers, separating solid walls are used to transfer heat. Mixing heat exchangers transfer heat by direct contract between cold and hot media (i.e. by mixing).

Surface devices are subdivided into the types as follows:

  • recuperative;
  • regenerative.

In recuperative heat exchangers, a separating wall with the special heat exchange surface (or the heating surface) is used to transfer heat. Regenerative heat exchangers are also provided with a heated wall, but the heat transfer process differs from that in a recuperative heat exchanger. In this type of devices, both heat exchangers alternately contact the same wall; this wall accumulates heat while hot flow is running and releases heat while cold flow is running. Regenerators are capable to operate in cycling mode only. Recuperators are capable to operate in both modes: continuous and cyclic.

Simplest heat exchanger

Heating/cooling jackets are the simplest heat exchangers. These jackets surround a heat exchanger’s housing where the required heat transfer agent (steam or water) flows. These devices are provided with mechanical mixers to make heat exchange processes more intensive.

Description of tubular heat exchanger

For tubular heat exchange devices, typical characteristics include easy design, small dimensions, high level of heat transfer capacity and adequate price. This type of heat exchangers is widely applied in chemical productions. The configuration of a tubular heat exchanger includes a cylinder-shaped tank with a tube section built in it. A tube section is a block of tubes laid in parallel and fastened in tube grids or plates. A tubular heat exchanger is provided with two chambers (cavities): a tube cavity and a housing cavity. In a tube section, one substance flows; in an intertube housing space, another substance flows. The effectiveness of heat exchange process is improved by turning the deflection shields in a housing, contributing to variation of media flow direction.

In a heat exchange devices provided with two tube grids, media can flow in two modes:

  • cross-counter;
  • cross-direct.

In this configuration, tubes are not readily accessible from the outside; therefore, the medium used within the housing must not contribute to formation of deposits. To clean the tubes in these devices, side shell rings must be previously removed.

The design of a heat exchanger with U-shaped tubes is implemented as a single tube grid with U-shaped tubes welded into it. A rounded part of a tube is freely supported by rotary shields in a housing cavity. Among the advantages of such a design, there is the capability to expand tubes linearly, thus making it possible to work at high variations of temperatures. To clean the tubes, the complete tube section must be removed from the housing. Only chemical cleaning is possible.

Tubular heat exchangers can be used as condensers. If this is the case, heat exchangers are placed vertically or obliquely. Vapor enters into the housing cavity where it is condensed. Condensate is then accumulated in a pocket and delivered outwards. Non-condensed vapors are removed by a vent valve. Cooling medium flows in tubes.

Tubular heat exchangers are often used in evaporators where they are installed vertically or obliquely. Media to be evaporated flows down in open tubes. It boils and then it is sprayed in a form of vapor bubbles into an evaporator chamber. Heating vapor is within the housing chamber. In accordance with the mode chosen, evaporators can be configured as:

  • flow-through devices (liquid flows through the evaporator only once);
  • natural circulation devices (liquid flows in a closed loop through a recirculation tube).

Mixing heat exchangers. Mixing condensers. Bubbler. Coolers

Heat exchange of substances (liquids, gases, granular materials) during their direct contact or mixing is notable for its maximum degree of intensity. Application of this technology is predefined by the process needs. The following equipment is used for liquids mixing:

  • a bulk-capacity devices provided with a mixer;
  • an injector (used also for continuous mixing of gases).

Heating of liquids can be carried out by vapor condensation in them. Vapor is delivered through multiple holes in a tube, which is bent in a circle or a spiral shape and placed in the bottom section of a heat exchanger. The device that maintains this process is called a bubbler.

The cooling-down of a liquid to a temperature about 0°C can be carried out by adding ice, that can absorb up to 335 kJ/kg of heat while melting, or liquefied neutral gases with moderate evaporation temperature. Refrigerating mixtures, which absorb heat after dissolution in water, are sometimes used.

The liquid can be preheated by contact with hot gas and can be cooled down, respectively, by contact with cold gas. This process is provided by scrubbers (vertical devices) where the flow of liquid to be cooled or heated flows down in the direction opposite to the rising flow of gas. A scrubber can be filled with various nozzles to increase the contact surface. Nozzles break the liquid flow into small streams.

A group of mixing heat exchangers also includes the mixing condensers implementing the function of condensation of vapors by their direct contact with water. Two types of mixing condensers are available:

  • direct flow condensers (vapor and liquid flow in the same direction);
  • counter flow condensers (vapor and liquid flow in opposite directions).

To increase the area of contact between vapor and liquid, the liquid flow is broken into small streams.

Air coolers with finned tubes

Many chemical plants generate large quantity of waste heat that is not recovered in heat exchangers and cannot be reused in processes. This heat is removed into the environment; therefore, the need to minimize possible consequences exists. For this purpose, various types of coolers are used.

The configuration of coolers with finned tubes consists of several finned tubes; the liquid to be cooled flows in these tubes. Fins, i.e. the finned configuration, significantly increase the cooler surface. To blow over the cooler fins, fans are used.

This type of coolers is used in cases when water cannot be used for cooling: for example, on a site where chemical plants are mounted.

Spray-type coolers

The design of a spray-type cooler is implemented as rows of serially-mounted coils, with the liquid to be cooled flowing in them. The coils are continuously sprayed by water; due to this, spraying is carried out.

Tower-type coolers

The operation principle of a tower-type cooler is as follows: preheated water is sprayed in the top part of a structure and then flows down over the packing. In the bottom part of a structure, due to the natural suction, air flow runs near flowing-down water and partially absorbs heat from water. Also, water is partially evaporated when it flows down; this also results in heat loss.

The disadvantages of this configuration include its huge dimensions. For example, tower-type cooler height can reach up to 100 m. An undoubted advantage of such a cooler is its operation without any auxiliary energy.

Tower-type coolers equipped with fans operate similarly. The difference is that the air is heated by a fan. It should be noted that the dimensions of a configuration with a fan are much smaller.

Materials for production of heat exchange equipment

Various materials are used to produce heat exchange devices. Such properties as heat conductivity and corrosion resistance are the important requirements involved while choosing the materials for production. The chosen material significantly influences the design of a heat exchanger . The most widely applied materials are metals such as carbon steels, alloyed steel, titanium and its alloys, copper. Along with metals, non-metal materials are also widely applied.

Heat exchangers made of copper are suitable for chemically pure and non-aggressive media such as fresh water. This material has high heat transfer coefficient. The disadvantage of these heat exchangers is their quite high cost.

Brass is an optimal solution for cleaned aqueous media. As compared with heat exchange equipment made of copper, brass is cheaper and has higher characteristics in terms of corrosion resistance and strength. It should be also noted that some brass alloys are resistant against sea water and high temperatures. The disadvantages of this material are its low characteristics in terms of electric conductivity and heat conductivity.

The most commonly used material for heat exchange devices is steel. By adding various alloying elements into steel, its mechanical, physical and chemical properties can be improved and application range can be expanded. Depending on the added alloying elements, steel can be used in alkaline or acidic media with various impurities and at high operating temperatures.

Titanium and its alloys are high-quality materials with high characteristics in terms of strength and heat conductivity. This material has very low weight, and it is applicable in a wide range of operating temperatures. Titanium and materials based on it demonstrate good corrosion resistance in most of acidic- or alkaline-type media.

Non-metallic materials are applied in cases when heat exchange processes have to be implemented in especially aggressive or corrosion-active media. For these materials, the typical characteristics are high values of heat conductivity coefficient and resistance against the most chemically active substances, making them irreplaceable materials applied in many devices. Non-metallic materials are subdivided into two types: organic and inorganic ones. Organic materials are carbon-based materials, such as graphite and plastic masses. As inorganic materials, silicates and ceramics are applied.

Choosing the heat exchange equipment: basic principles

Upon becoming the official distributer of heat exchangers, our company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), carries out the following: finds the buyers of your products on the market, conducts technical and commercial negotiations with the customers regarding the supplies of your equipment, concludes contracts. Should a bidding take place, we will collect and prepare all the documents required for the participation, conclude all the necessary contracts for the supply of your equipment, as well as register the goods (heat exchangers) and conduct customs clearance procedures. We will also register a certificate of transaction (Passport of Deal) required for all foreign trade contracts in the foreign currency control department of the authorized Russian bank so that currency transaction could be effected. If required, our company will implement an equipment spacing project in order to integrate your equipment into the existing or newly built production plant.

We are convinced that our company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), will become your reliable, qualified and efficient partner & distributor in Russia.

We are always open for cooperation, so let’s move forward together!