Construction of a heat exchanger for stove heating

The content of the article:

The need for boiler equipment in a heating furnace
DIY heat exchanger manufacturing
Creating a heating wiring diagram
Expert opinion on a home-made heat exchanger in a heating furnace

For an autonomous heating main of a private house or bath, a stationary stove is used. Due to the high heat transfer and efficiency, a comfortable temperature is quickly pumped. To reduce the cost of arranging the system, a boiler in a heating furnace can be made independently.

The need for boiler equipment in a heating furnace

To save fuel, use hot air, you can build a heat exchanger for the furnace

When fuel is burned in a furnace, useful heat is directed into the air or leaks through a chimney. In some cases, a low-power heating unit is not enough for efficient heating of the coolant. Furnace boilers are justified for several reasons:

full heating of distant rooms - no need to connect additional electrical appliances;
the creation of a thermal curtain - the windows do not sweat, the house does not undergo decay processes;
improvement of circulation inside the heating system - the temperature difference is preserved in different sections of the coolant;
Corrosion elimination on metal parts of the furnace.

You can combine stove heating with radiator wiring in the house using the boiler built into the heating or cooking surface.

DIY heat exchanger manufacturing

You can weld a flat heat exchanger from sheets of steel or stainless steel

It is allowed to integrate flat, air and tubular heat exchangers with one's own hand. When constructing the device, it is necessary to take into account the labor costs and the cost of the project.

Simple fixture

A flat heat exchanger increases the efficiency of the stove; it is installed vertically or horizontally in the boiler. It is easy to remove soot and soot from the element, and due to its large volume it can be adapted to the needs of hot water supply.

The plate heat exchanger looks like a pipe of large diameter, inside of which there is a smaller one. Water moves along it in the heated state, the cooling process takes place in a large nozzle.

Do-it-yourself construction is made of copper tubes. One should be larger than the other by 4 mm in diameter. The work is carried out as follows:

Fastening by welding a side tee on two sides of the tube from the outside.
Installing a smaller nozzle.
Welding an element to the ends of a large tube in a pre-fixed position.
Installation of short tubes at the outlet to the tees. They are needed for the movement of the coolant.
Connection of parts by segments with alternate welding of tees to the side parts in the form of a snake.

Steel tubes should be larger than copper, assembly is carried out block by block.

Complex recuperator

More complex types of pipe and flat steel plate exchangers

The heat-exchange boiler for furnace heating looks like a tank with pipes and a heater. It consists of two sectors with mutual heating. The coolant circulates, getting into the closed loop of the tank, heats up to 180 degrees. Water is routed to the main line after passing through small pipes.

To weld the heat exchanger yourself, you will need such materials:

finished tank with a capacity of 90 to 110 l;
sheet steel 2.5-3 mm thick, if the tank is made by hand;
anode;
2 copper pipes up to 4 m long for heating elements;
device that controls the heating power.

Installing the heat exchanger in the furnace - the inlet and outlet pipes are marked with numbers

Before starting work, it is necessary to make a drawing of the finished product, and then proceed to assembly:

Install the tank at a height of 1 m from the floor and 3 m from the stove.
Make two holes on the right side of the stove and on the top left.
Draw a tap for water heating devices from below, tilting it by 2-3 degrees.
Connect the upper branch in the opposite direction with an inclination of 20 degrees.
Insert 2 drain taps into the bottom outlet for the tank and for the system.
Seal the holes tightly to evenly warm the rooms.
Bend the copper tube in a spiral shape.
Install the finished coil in the tank, bring the ends out and fix them.
Attach threaded fittings to the coil end.
Connect a ready-made power regulator to the pipe.
Throw terminals on the thermostat for power, and then wires.
Install an anode to prevent tank wear from temperature fluctuations.
Seal the seams and all parts with a special tool.

The finished heat exchanger is filled with water and checked for leaks. If everything is in order, the boiler for the stove can be put into operation.

Creating a heating wiring diagram

Combining the furnace with a water boiler and connecting the circuit to the heating system can be done in two ways.

Open system

With the system open, the expansion tank is at the top point - in the attic, you can turn on the pump

The coolant moves in a gravitational manner, so the installation of a circulation pump is required. It is put on bypass, reduces the temperature difference between the return and supply, increases the speed of water and the quality of heat transfer. Without electricity, the line will work on the principle of gravity.

To organize it, you will need to increase the line and the horizontal slopes in diameter. The open system is equipped with a 32 mm distributing collector with an inclination from 3 to 5 mm per linear meter. The expansion tank is located at the top, it receives air from the communications.

Closed system

The radiator network provides for the forced movement of water. Traction in this case creates a pump. It also pumps up pressure from 1 Bar for a cold coolant. The membrane type tank is located below. A shut-off valve is used to connect it to the highway. Safety devices (air vent, pressure gauge, bleed valve) are required.

An autonomous boiler in a brick oven is best connected by gravity.

Expert opinion on a home-made heat exchanger in a heating furnace

The furnace with a water circuit starts with wood once a day

Professionals make several comments about installing the boiler in a heating installation:

The effectiveness of the result of a combined system without overpayments.
The ability to use any type of fuel. Sawdust, coal, pallets and firewood stored in a dry place are suitable.
The furnace unit, which has a water boiler, does not need to be constantly heated. Fuel is laid once every 12-24 hours.
The system, where a long type of combustion is implemented, allows you to warm up the building with high quality and provide hot water.
In the absence of welding skills and an understanding of the manufacturing process, homemade heating appliances should be avoided. As an exception, installation in a country house or in settlements with power outages is considered.
The optimal type of chimney for a stove with a boiler tank is bell-type. The heat exchanger in the form of a register of pipes with a large cross-section is placed inside.
In order not to splurge on copper fittings, you can work with seamless pipes. They do not crack when heated.

A home-made solid fuel unit with a water circuit can be used in winter. It quickly and efficiently heats large housing, ensures uninterrupted supply of hot water. Before starting work, you need to choose a quality material for the heat exchanger, which will not be heated from the surface of the furnace structure.

Alexei

The heat exchanger in the furnace is a good idea, but its implementation in the form presented here is a waste of money if this heat exchanger comes in direct contact with the fire. Over time, metal burns out, though I don’t know which metal burns out faster - copper or iron))). At my place there is a stove and the upper brickwork is at the corner 50, the thickness is decent - about 5 mm. It lasts a maximum of 5 years, and then under the influence of fire it bends. Yes, and probably many were faced with the fact that if the pipe is made of metal, which is especially practiced in baths, then it burns out quickly enough. To avoid problems, it is necessary to isolate the heat exchanger from fire - it is better to place it in a “shirt” made of bricks and then it will last for decades. And so you can lose the stove and heat in the house at one point.

To answer

Sergei

My grandfather in the furnace, as a heat exchanger, were mounted two cast-iron batteries in five sections. All boiler rooms are built on cast-iron heat exchangers.

Nikolay

well done, a lot of work, but the boiler is designed for uniform combustion and heating in all directions, however, the gases go into the chimney and the heat exchanger should have a large area of heat in this direction, i.e. in a checkerboard pattern pipes are welded in 2-3 rows in the direction of the chimney and more, a straight line is welded into the upper plane of the tank, preferably.

Gennady.

An open expansion tank crashes into the return line until the pump when you insert there will be water hammer (knock).

Do you have a kettle on a gas stove for how long 5 years? It’s right if it burns out without water and it burns out in half an hour And there the water is so brave enough for 20-25 years and if pipes with a diameter of at least 50 spruce less will boil faster then you need to set the pump more powerful And the stove that you blocked the furnace with a corner in the face plinth is not the stove but the cobbler who tore money from you

Eugene

Your square burns out because there is nowhere to give the received heat.