The heat exchanger in the flue pipe: air and water coil with their hands

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The furnace is used for heating or cooking food at home, you can alter their own hands under the unit, which will heat the water for domestic use. For this we need to spend on the installation of the heat exchanger pipe of the chimney. How to do it, look at the article.

A heat exchanger mounted on the chimney pipe

What is a heat exchanger

This technical device made of a material with high thermal conductivity, wherein the two media with different temperatures come into contact through the septum. It is through the wall of the device from one environment to another temperature is passed.

There are two types of heat exchangers:

  1. Recuperators. That is, those in which the temperature of the transmission takes place through the partition.
  2. Regenerators. In these environments with different temperatures come into contact with the surface of a single turn.
The principle of operation of the heat exchanger

There are several types of heat exchangers, which differ from each other purely structural performance. It is commonly used options:

  1. Coil - a tube wound on a chimney, through which water moves.
  2. Nestable. This design in the form of a cylinder fitted on the chimney. Inside it proceeds the water which enters into the structure through the bottom nozzle and out through the nozzle set top of the heat exchanger. Heating of liquid occurs through the chimney wall.
  3. Spiral. In everyday life rarely used because constructively - a container, which is laid in a spiral (on inner walls) pipe, inside the hot medium is moving. Unfortunately, in such a chimney will not work.
  4. Shell and tube. This is not a household unit. Its design - a container in which is inserted a large number of tubes. By moving them medium with high temperature and the water moves between the tubes.
  5. Plate, also called convectors. This model is the same as the previous one. Only in tubes installed therein instead of the hollow panel and which moves at a high temperature. A water therebetween. The efficiency of heat transfer is dependent on in which direction relative to each other are moved medium. Optimally - to meet each other.
Spiral heat exchanger unit type

There is another classification, in which the heat exchangers are divided into water and air. On the first it was written above. As to the second, then use them mainly organize additional heating. A prominent representative of such units acts corrugated heat exchangers.

For this purpose, steel corrugated tube (flexible they) which wrap around the chimney. It turns out that carbon monoxide with the high temperature gases coming from the furnace firebox, give the heat to the air passing inside the flutes. The latter is connected with the street, it is usually introduced into the space through an opening located close to the floor. Sometimes establish a low-power fan to give the air a little speed. The opposite end of bellows installed in the room where it is required to raise the temperature.

Materials for heat exchangers

Usually chimney collected from the metal pipes. Rarely in the sauna bath or other premises than the primary home mounted ceramic or glass chimneys. Too expensive. Therefore, we can safely say that these structures have a high thermal efficiency. Therefore, they can be mounted in the heat exchanger.

The coil of copper tube

Material of heat exchanger is chosen on the basis of keeping large thermal loads, because the unburned gas temperature can reach up to + 500C. Plus, you need to take into account the negative impact of water on the metal. Therefore, the coil tube to be manufactured or a copper alloy, or stainless steel.

When it is decided to construct a heat exchanger tube in tube type, then the better use of its manufacturing design of stainless steel or galvanized.

How to install the coil on the chimney

This twisted design is considered to be the simplest. It is the co-current, so much will depend on the diameter of the tube being wound and speed of movement of water within it. Here, the ratio of these:

  • The larger diameter of the coil, the greater the volume of water in it, which will be heated longer.
  • The faster the coils on the water, the less it takes heat energy, just no time.

Solve these two problems in two ways:

  1. Increase pipe length, the twist in the coil. That is, the water as long as possible should be located within the heat exchanger.
  2. Set in front of the coil off valve by means of which one could control the flow of fluid. In this way it is possible to increase or decrease the water velocity.

Installation of the water heat exchanger of this type is carried out in step chimney installation. Because it is necessary to insert a coil flues.

This will require:

  • pipe of copper, aluminum or steel length 3 m;
  • two flexible hose to connect to the hot water supply system, the required length;
  • valve.
How to bent pipe to the coil

The hardest part - to bend the pipe to the coil. If this is a steel product with a diameter less than 25 mm, it can be bent to the hand tube bender. If the diameter is larger than this value, or used aluminum, copper pipe, they can not do without heating. To do this, use the standard gas burners on propane.

There is another way, which is now practically used. For this purpose, the tube is filled fine screened sand, on both sides it is closed with plugs, and then bend along the pipe diameter of 100, 120 or 150 mm. That is the appropriate size of the chimney. After finished design free from filler, and washed with water under pressure.

The next step - cutting the thread at the end of the coil. To do this, use a chaser. If the heat exchanger is made of a steel pipe, then the ends can be welded by electric welding sleeves with the corresponding diameter for flexible hoses transient.

Everything is ready, you can mount the heat exchanger. So it does not fall from the chimney, it can be attached to it by soldering. At the same time, and increase the heat exchange between the two elements. Further, the bottom of the valve is screwed, thereto a flexible insert which is attached to the opposite end of the water supply.

The coil of copper tube in the oven chimney

The free upper end of the heat exchanger unit or connected to a storage tank or to the tap. To connect using flexible insert.

In this type of heat exchanger has one serious drawback. If it is not used when operated stove, the water inside the tubes boils. And it is not far to the water hammer that can break the joint connector.

As set exchanger "pipe in pipe" at the chimney

Purely constructively heat exchanger of this type is a tank in which is installed a pipe with a diameter slightly larger diameter of the chimney. For example, if the size of the last 115 mm, the pipe section should be in the cross section of 120 mm. That is, the chimney must be free to pass through the heat exchanger.

One can approach the solution of the heat exchanger assembly with the other hand. That is, the diameters of the two pipe elements are selected one section. But they need to connect push-fit manner, all the elements of the chimney. This is where one end has a standard diameter at the portion of the tubular member, and the second bit expanded.

Stainless steel pipe with sockets at the ends

That is, it turns out that the tube forming the through passage through the water tank becomes part after assembling the chimney. This option is more efficient in transferring heat energy from the unburned gases water, because the heat exchanger designs no air layer as in the first case.

With regard to the size and shape of the tank, the first - the diameter of which must be greater than the diameter of the chimney constructions by 1.5-2.0 times. Length in this regard depends on the need for water. But it is limited by the length of the chimney. The shape of the tank may be different. But more likely to use a cylindrical or in the form of a direct box. Though there are very unusual shapes.

The unusual shape of the water tank of heat exchanger

Note that the water tanks installed on chimneys, now sold as a finished product, but they are easy to make with your own hands. For this we need to have the skills to work with welding machine and some kinds of handtools. Easier - buy a certain amount of the finished product, which is already mounted chimney pipe under the required section. Here installed pipes (choke) for feeding and outlet of water.

The assembly of the whole structure is based on the creation of sealed connections. Therefore, be sure to joints are coated heat-resistant sealants.

After installation of the coolant can only connect it through a valve to the water supply and on the other side to the storage tank or tap (faucet). Compounds conducted flexible inserts or the corresponding diameter pipes.

Exchanger "pipe in pipe" in full assembly

Important! The heat exchanger of this type before using it is necessary to fill with water. If you start kindling without it, it is likely that the metal lead, and this will lead to depressurization joints parts.

Conclusion Related

The heat exchanger installed on the oven chimney, this is a real opportunity to save on hot water supply organization. It is important to correctly carry out the installation, taking into account the requirements of fire safety.