Hot sand delivered or how to warm up (warm up) soil or soil in winter. Warming up the soil in winter Methods for heating the soil in winter

Excavation V winter period complicated by the need for preliminary soil preparation. The use of jackhammers or other mechanical action is not always justified, and sometimes is simply impossible. There is a possibility of damaging underground communications or causing damage to nearby buildings. Therefore, widespread thermal methods impact.

Traditional types of heating frozen soil

Many technologies have been developed based on different principles thermal effects. Each of them has advantages and disadvantages.

Reflex oven

Fast, convenient and mobile method is well suited for working in urban areas. Nichrome wire 3.5 mm thick serves as a heat generator. Direction thermal radiation corrected by a reflector made of chrome sheet about 1 mm thick.


The reflector itself is protected by a metal casing. Between the walls of two metals there is air bag, which plays the role of thermal protection. The stove operates from a 127/220/380V network and is capable of heating 1.5 m2 of soil. For warming up cubic meter soil requires about 50 kW/hour of electrical energy and 10 hours of time. Significant flaws of the method:

1. high probability of defeat electric shock strangers. Fencing and security are required while the installation is operating;
2. small coverage area;
3. an energy supply system with a capacity of about 20 kW/hour is needed to operate a complex of three units.

Electrodes

They are made from round or strip steel, driven into the ground and connected to a power source. The surface of the soil is covered with sawdust and soaked in saline solution. This layer serves both as a conductor and as insulation.


Electricity consumption for thawing a cubic meter of soil is 40-60 kW, and the process takes 24-30 hours. Among the disadvantages of the method it should be noted:

1. high probability of electric shock to unauthorized persons;
2. requires a constant supply of electricity;
3. defrosting of the soil takes a very long time;

Open flame

The method is based on the combustion of liquid or solid fuel in a special device consisting of open tanks. The design provides that the first box serves as a combustion chamber, and the last is equipped exhaust pipe. Users note the disadvantages of the technology:

1. significant losses of thermal energy;
2. You must first complete a set of preparatory work;
3. harmful emissions and the need for constant monitoring.

Chemical method

To defrost the soil using chemical reagents, holes are drilled into the soil. Sodium chloride is then poured into the holes to dissolve the ice. The entire process lasts from six to eight days. Disadvantages of the chemical method:

1. defrosting takes a long time;
2. the need for arrangement of pits;
3. the environmental friendliness of the process raises many questions;
4. materials cannot be reused.

Steam needles

Actually, a pipe two meters long and up to 50 mm in diameter can hardly be called a needle. Water vapor is supplied through it into the soil. To install the needles, you first need to drill holes to a depth of at least 70% of the height of the thawing layer. After connecting to the steam supply system, the wells themselves are closed with caps and covered with a layer of thermal insulating material.


The main disadvantages of the method are:

1. need for training;
2. the need for a steam generator;
3. formation and further freezing of condensate;
4. careful control over the process is required.

Hot coolant

The soil is heated by the hot mineral (100-200 degrees Celsius) that covers the surface of the earth. Waste is often used road production– defective asphalt or concrete chips. Defrosting time is at least 20-30 hours. The disadvantages of this method should be noted:

1. dependence on a subcontractor;
2. heat loss during coolant delivery;
3. the need to clean up the coolant after the ground freezes;
4. long thawing period.

Tubular electric heaters

The technology involves the transfer of thermal energy by contact method. The working elements are electric needles. They are meter-long pipes with a diameter of 50-60 mm. Electric heating elements are installed inside.
The heating elements are located horizontally in the ground and connected to the circuit in series. The disadvantages of this method are:

1. the need for constant monitoring;
2. possibility of electric shock;
3. small thawing area;
4. need for preparatory work.

Heating the soil with thermoelectromatic devices

A great alternative existing methods warming up the soil is heating it using thermomats. They ensure uniform heating of the soil throughout its depth and maintain the set temperature automatically.
The equipment is manufactured on the basis of heat-emitting films. It is produced various sizes and configurations. The panel thickness is about 10 mm. It operates from a single-phase network and can generate temperatures up to 70 0C. Directed Action infrared radiation defines high efficiency device operation.


Advantages of using FlexiHit thermoelectromats.

There is one a big problem by doing construction work V cold period of the year. Many builders are familiar with this problem and constantly face it.
The surface of the earth, gravel, clay, sand freezes, and the fractions freeze together, which makes it impossible to carry out excavation work without additional time.

There are several ways to thaw soil:

• 1. Brute force. Mechanical destruction.
• 2. Thawing using heat guns.
• 3. Burning. Oxygen-free combustion.
• 4. Defrosting using a steam generator.
• 5. Thawing with hot sand.
• 6. Thawing with chemical reagents.
• 7. Warming up the soil thermoelectric mats or heating electric cable.

Each of the above methods has its own weak sides. Long, expensive, poor quality, dangerous, etc.
The optimal method can be considered a method using an installation for heating soil and concrete. The earth is warmed by liquid circulating through hoses laid out on a large surface.

Advantages over other methods:

• Minimal preparation of the heated surface
• Independence and autonomy
• The heating hose is not energized
• The hose is completely sealed and is not afraid of water
• The hose and heat-insulating blanket are resistant to mechanical stress. The hose is reinforced synthetic fiber and have exceptional flexibility and tensile strength.
• The serviceability and readiness of the equipment for operation is monitored by built-in sensors. A puncture or rupture of the hose is visible visually. The problem can be fixed in 3 minutes.
• There are no restrictions on the heated surface.
• The hose can be laid as desired

Stages of work using the Wacker Neuson HSH 700 G surface heating unit:

Site preparation.
Clear the heated surface of snow.
Thorough cleaning will reduce the defrosting time by 30%, save fuel, and get rid of dirt and excess melt water that complicates further work.

Laying a hose with coolant.
The smaller the distance between the turns, the less time it will take to warm up the surface. The HSH 700G unit has enough hose to heat an area of ​​up to 400 m2. Depending on the inter-hose distance, the required area and heating rate can be achieved.

Vapor barrier of the heated area.
The use of a vapor barrier is mandatory. The unfolded hose is covered plastic film overlap The film will not allow the heated water to evaporate. Melt water will instantly melt the ice in the lower layers of the soil.

Laying thermal insulation material.
Insulation is laid over the vapor barrier. The more thoroughly the heated surface is insulated, the less time it will take to warm up the soil. The equipment does not require specific knowledge of skills and long-term training of personnel. The installation, steam and thermal insulation procedure takes from 20 to 40 minutes.

Advantages of technology using an installation for heating surfaces

• Heat transfer 94%
• Predictable result, complete autonomy
• Preheating time 30 minutes
• No risk of electric shock, does not create magnetic fields or interfere with control devices
• Laying the hose in free form, no restrictions on terrain
• Ease of operation, control, assembly, storage exceptional flexibility maneuverability and maintainability
• Does not affect or destroy nearby communications and the environment
• The HSH 700 G unit is certified in Russia and does not require special permits for the operator

Possible applications for the Wacker Neuson HSH 700 G

• Soil thawing
• Laying communications
• Warming up the concrete
• Warming up complex structures(bridge columns, etc.)
• Warming up reinforcement structures
• Thawing gravel for laying paving stones
• Warming up prefabricated formwork structures
• Preventing icing of surfaces (roofing, football fields etc.
• Gardening (greenhouses and flower beds)
• Finishing work on a construction site during the “cold” period
• Heating of residential and non-residential premises

Surface heating devices from Wacker Neuson are economical and effective solution for the winter period, allowing projects to be completed on time.
In autumn and spring, they also make an invaluable contribution to the workload of your enterprise: after all, these devices speed up many technological processes.

The main purpose of heating concrete is to maintain the right conditions removal of moisture during work in winter time or for limited periods. The principle of operation of the technology is to support within or around the thickness of the solution elevated temperature(within 50-60 °C), implementation methods depend on the type and size of structures, grade of mixture strength, budget and conditions external environment. To achieve the desired effect, heating must be uniform and economically feasible, top scores observed when combined.

Overview of heating methods

1. Electrodes.

Simple and reliable way electrical heating, which consists of placing reinforcement or wire rod 0.8-1 cm thick in a wet solution, forming a single conductor with it. Heat release occurs evenly, the impact zone reaches half the distance from one electrode to another. The recommended interval between them varies from 0.6 to 1 m. To start the circuit, the ends are connected to a power supply with a reduced voltage from 60 to 127 V; exceeding this range is possible only when concreting unreinforced systems.

The scope of application includes structures with any volume, but the maximum effect is achieved when heating walls and columns. Electricity consumption in this case is significant - 1 electrode requires at least 45 A, the number of rods connected to the step-down transformer is limited. As the solution dries, the applied voltage and costs increase. When pouring reinforced concrete products, the technology of heating with electrodes requires agreement with specialists (a design for their placement is drawn up, excluding contact with metal frame). At the end of the process, the rods remain inside, reuse is excluded.

2. Laying wires.

The essence of the method lies in the location in the thickness of the solution electric wire(in contrast to electrodes - insulated), heated by passing current and uniformly releasing heat. One of the following types is used as work elements:

• PNSV – polyvinyl chloride insulated steel cable.
• Self-regulating sectional varieties: KDBS or VET.

The use of wires is considered the most effective when it is necessary to fill floors or foundations in winter; they transform electrical energy into heat and ensure its uniform distribution.

PNSV is cheaper; if necessary, it is laid over the entire area of ​​the structure (the length is limited only by the power of the step-down transformer); for these purposes, a cross-section from 1.2 to 3 mm is suitable. Features of the heating technology include the need to use installation wires with an aluminum core on open areas. The automatic reclosure cable has suitable characteristics. The PNSV 1.2 scheme excludes overlaps; the recommended step between adjacent rings and lines is 15 cm.

Self-regulating sections (KDBS or VET) are effective for heating in winter without the possibility of using a transformer or supplying 380 V. Their insulation is better than that of PNSV, but they are more expensive. The wire laying scheme is generally similar to the previous one, but its length is limited, it is selected taking into account the dimensions of the structure, and it cannot be cut. When adding a current control device to it, heating is carried out more smoothly and economically. In general, both options are considered effective when concreting in winter; the only disadvantages include the complexity of installation and the impossibility of re-use.

3. Heat guns.

The essence of the technology is to increase the air temperature using electric, gas, diesel and other heaters. The elements being processed are covered from the cold with a tarpaulin; creating such a tent allows you to achieve indoor conditions from +35 to 70 °C. Heating is carried out by an external source, which can be easily transferred to another place without the need for wire consumption or special equipment. Due to the difficulty of covering large objects and affecting only the outer layers, this method is more often used for small volumes of concreting or when there is a sharp drop in temperature. Energy consumption in comparison with electrodes or PNSV is acceptable; when using diesel guns, heating is possible at sites without power supply.

4. Thermal mats.

The principle of operation of this technology is based on covering the freshly poured solution with polyethylene and infrared film sheets in a moisture-resistant shell. Thermal mats are connected to a regular network, the energy consumption varies between 400-800 W/m2, when the limit reaches +55 ° C they are turned off, which reduces the cost of electrical heating of concrete. Maximum effect from use is achieved in winter, including when combined with chemical additives.

The risk of moisture freezing inside the concrete products is eliminated after 12 hours, the process is completely autonomous. Unlike PNSV wires, thermomats contact without problems open air and moisture, in addition to concrete structures, they are successfully used to warm the soil.

At proper care(no overlaps, bends strictly along designated lines, protection with polyethylene) IR films can withstand at least 1 year of active use. But despite all the advantages, the technology is poorly suited for heating massive monoliths; the effect of the mats is local.

5. Heating formwork.

The principle of operation is similar to the previous one: between two sheets of moisture-resistant plywood is placed infrared film or asbestos-insulated wires that generate heat when connected to the network. This method provides heating in winter to a depth of up to 60 mm; thanks to local exposure, the risk of cracking or overstrain is eliminated. By analogy with mats, these heating elements have thermal protection (bimetallic sensors with auto-return). The scope of application includes structures with any slope; the best results are observed when pouring monolithic objects, including those with limited construction time, but the technology cannot be called simple. When concreting the foundation, a solution with a temperature of at least +15 °C is poured into the heating formwork; the soil needs to be preheated.

6. Induction method.

The operating principle is based on the generation of thermal energy under the influence of eddy currents; the method is well suited for columns, beams, supports and other elongated elements. The induction winding is placed on top metal formwork and creates an electromagnetic field, which in turn affects the reinforcing bars of the frame. Heating of concrete is carried out evenly and efficiently with average energy consumption. Also suitable for preliminary preparation of formwork panels in winter.

7. Steaming.

An industrial version, to implement this method, a double-walled formwork is required, which not only can withstand the mass of the solution, but also supply hot steam to the surface. The quality of processing is more than high; unlike other methods, steaming provides the most suitable conditions for cement hydration, namely a moist, hot environment. But due to its complexity, this technique is rarely used.

Comparison of advantages and limitations of heating technologies

The labor intensity of extracting frozen soil is extremely high due to its significant mechanical strength. In addition, the frozen state of the soil complicates the task of excavating it due to the inability to use certain types of earthmoving and earthmoving-transport machines, reduced productivity and accelerated wear of the working parts of the equipment. And yet, frozen soil has one advantage - it is possible to dig pits in it without installing slopes.

There are four main ways to carry out excavation during the cold season:

• protection land plot works against freezing with the further use of conventional earth-moving machines;
• preliminary loosening and excavation of frozen soil;
• direct development of soil in a frozen state, i.e. without any preparation;
• bringing to a thawed state and subsequent removal.

Let's look at each of the above methods in detail.

Protecting soils from freezing

Protection from low temperatures is provided to the soil by loosening the top layer, covering insulating materials and pouring aqueous salt solutions.

Plowing and harrowing of the land plot is carried out in the sector further work for soil extraction. The result of such loosening is the input large quantity air into the soil layers, the formation of closed air voids that prevent heat transfer and maintain a positive temperature in the soil. Plowing is carried out with rippers or factor plows, its depth is 200-350 mm. Next, harrowing is carried out in one or two directions (crosswise) to a depth of 150-200 mm, which ultimately increases the thermal insulation properties of the soil by at least 18-20%.
The role of insulation when covering the site of future work is performed by cheap local materials - dry moss, sawdust and shavings, fallen tree leaves, slag and straw mats, you can use PVC film. Bulk materials are placed on the surface in a 200-400 mm layer. Insulation of the soil surface is most often carried out on small plots of land.

Frozen soil - loosening and excavation

To reduce the mechanical strength of winter soil, methods of mechanical and explosive processing are used. The soil loosened in this way is then removed in the usual way- using earthmoving machines.

Mechanical loosening. During its implementation, the soil is cut, chipped and split due to static or dynamic loads.

Static loads on frozen soil are carried out metal tool cutting type - tooth. A special hydraulically driven design, equipped with one tooth or more, is carried out across the work site while being placed on a crawler excavator. This method allows you to remove soil layer by layer to a depth of up to 400 mm for each pass. During the loosening process, the installation equipped with a tooth is first pulled parallel to the previous passes with a distance of 500 mm from them, then it is carried transversely to them at an angle of 60 to 90 degrees. The volume of frozen soil excavation reaches 20 cubic meters per hour. Layer-by-layer static development of frozen soil ensures the use of loosening installations at any depth of soil freezing.

Impact loads on unpaved areas allow you to reduce the mechanical strength of frozen ground due to dynamic effects. Hammers are used free fall, providing splitting and loosening, or hammers with a directed action for loosening by splitting. In the first case, a hammer in the form of a ball or cone is used greatest mass 5 tons - it is secured with a rope to the boom of an excavator and, after being lifted to a height of five to eight meters, it is dropped onto the work site. Ball hammers are best suited for sandstones and sandy loams, clay soils Conical hammers are effective, provided that the freezing depth does not exceed 700 mm.

Directed action on frozen soil is carried out by diesel hammers mounted on a tractor or excavator. They are used on any soil provided the freezing depth is no more than 1300 mm.

Reducing the strength of frozen ground by explosion is most effective - this method allows for winter excavation at a depth of 500 mm and when significant volumes need to be extracted. In undeveloped areas, open blasting is carried out, and in partially built-up areas, it is necessary to first install shelters and explosion limiters - massive slabs of metal or reinforced concrete. The explosive is placed in a crack or hole (with a loosening depth of up to 1500 mm), and if it is necessary to excavate soil at greater depths, in cracks and wells. Drilling or milling machines are used to cut slots; the slots are made at a distance of 900-1200 mm from each other.

The explosive is placed in the middle (central) slot, and the slots located nearby will provide compensation for the explosive shift of frozen soil and dampen the shock wave, thereby preventing destruction outside the work area. An elongated charge or several short charges at once are placed in the gap, then it is filled with sand and compacted. After the explosion, the frozen soil in the work sector will be completely crushed, while the walls of the trench or pit, the creation of which was the purpose of the excavation, will remain intact.

Development of frozen soil without its preparation

There are two methods of direct soil development in low temperature conditions - mechanical and block.

The technology for mechanical development of frozen soils is based on force, in some cases including shock and vibration. During its implementation, both conventional earthmoving machines and those equipped with special tools are used.

At shallow freezing depths, conventional earth-moving machines are used to extract soil: excavators with a direct or reverse bucket; draglines; scrapers; bulldozers. Single-bucket excavators can be equipped with a special attachments- buckets with gripping pincers and vibration-impact teeth. Such equipment allows you to influence frozen soil through excessive cutting force and carry out its layer-by-layer development, combining loosening and excavation in one working operation.

Layer-by-layer soil extraction is carried out with a special earth-moving and milling installation, which cuts off layers 2600 mm wide and up to 300 mm deep from the work site. The design of this machine includes bulldozer equipment that ensures the movement of cut soil.

The essence of block mining is cutting frozen soil into blocks and then removing them using a tractor, excavator or construction crane. The blocks are cut by sawing through the soil with cuts perpendicular to each other. If the ground is frozen shallow - up to 600 mm - then to remove the blocks it is enough to make cuts along the area. Slots are cut to 80% of the depth to which the soil is frozen. This is quite sufficient, since a layer with weak mechanical strength located between the frozen soil zone and the zone maintaining a positive temperature will not interfere with the separation of soil blocks. The distance between the slits should be approximately 12% less than the edge width of the excavator bucket. Extraction of soil blocks is carried out using backhoe excavators, because... It is quite difficult to unload them from the bucket of a straight shovel.

Methods for thawing frozen soil

They are classified according to the direction of heat supply to the ground and the type of coolant used. Depending on the direction of supply of thermal energy, there are three ways to defrost the soil - upper, lower and radial.

The top supply of heat to the ground is the least effective - the source of thermal energy is located in the air space and is actively cooled by air, i.e. a significant amount of energy is wasted. However, this method of thawing is the easiest to organize and this is its advantage.

The thawing procedure carried out from underground is accompanied by minimal costs energy, as heat spreads under a strong layer of ice on the ground surface. The main disadvantage of this method is the need to carry out complex preparatory measures, so it is rarely used.

The radial distribution of thermal energy in the soil is carried out using thermal elements vertically recessed into the ground. The effectiveness of radial thawing is between the results of upper and lower soil heating. To implement this method, somewhat smaller, but still quite high amounts of work on preparing the heating are required.

Defrosting the soil in winter is carried out using fire, electric thermocouples and hot steam.
The fire technique is applicable for digging relatively narrow and shallow trenches. A group of metal boxes is placed on the surface of the work site, each of which is a truncated cone cut in half. They are placed with the cut side on the ground close to each other and form a gallery. Fuel is placed in the first box, which is then ignited. The gallery of boxes becomes a horizontal exhaust pipe - the exhaust comes from the last box, and combustion products move along the gallery and heat the ground. To reduce heat loss from contact of the box body with air, they are covered with slag or melted soil from the area where work was carried out previously. The strip of defrosted soil formed at the end of heating must be covered with sawdust or covered with PVC film so that the accumulated heat contributes to further thawing.

Electrical heating of frozen soil is based on the ability to heat materials when an electric current is passed through them. For this purpose, vertically and horizontally oriented electrodes are used.

Horizontal defrosting is carried out using electrodes made of round or strip steel laid on the ground - to connect electrical wires to them, opposite ends steel elements bend by 150-200 mm. The heated area with the electrodes placed on it is covered with sawdust (layer thickness - 150-200 mm), pre-moistened with a saline solution (salt concentration - 0.2-0.5%) in an amount equal to the initial mass of sawdust. The task of sawdust soaked in saline solution is to conduct current, since frozen soil will not conduct current at the initial stage of work. The top layer of sawdust is closed PVC film. As it warms up, the upper ground layer becomes a current conductor between the electrodes and the intensity of thawing increases significantly - first the middle layer of soil is thawed, and then those located below. As the layers of soil are included in the conduction of electric current, the layer of sawdust begins to perform a secondary task - the conservation of thermal energy in the work area, for which it is necessary to cover the sawdust wooden shields or roofing felt. Thawing of frozen soil with horizontal electrodes is carried out to a freezing depth of up to 700 mm, the energy consumption when heating a cubic meter of earth is 150-300 MJ, the sawdust layer is heated to 90 o C, no more.

Vertical electrode defrosting is carried out using rods made of reinforcing steel and having one sharp end. If the freezing depth of the soil is 700 mm, the rods are first driven in to a depth of 200-250 mm in a checkerboard pattern, and after the top layer has thawed, they are sunk to a greater depth. In the process of vertical defrosting of the soil, it is necessary to remove the snow that has accumulated on the surface of the site and cover it with sawdust soaked in saline solution. The heating process proceeds in the same way as with horizontal thawing using strip electrodes - as it thaws upper layers it is important to periodically immerse the electrodes further into the ground to a depth of 1300-1500 mm. At the end of the vertical thawing of the frozen soil, the electrodes are removed, but the entire site remains under a layer of sawdust - for another 24-48 hours the soil layers will defrost on their own thanks to the accumulated thermal energy. Electricity costs for vertical defrosting are slightly lower than for horizontal defrosting.

For electrode heating of the soil in the direction from bottom to top, it is necessary preliminary preparation wells - they are drilled 150-200 mm deeper than the freezing depth. The wells are located in a checkerboard pattern. This method characterized by lower energy costs - about 50-150 MJ per cubic meter of soil.

The electrode rods are inserted into the prepared wells, reaching the unfrozen layer of the earth, the surface of the area is covered with sawings soaked in saline solution, and laid on top plastic film. As a result, the thawing process occurs in two directions - from top to bottom and from bottom to top. This method Thawing of frozen soil is carried out rarely and only when it is necessary to urgently defrost an area for excavation.

Steam defrosting is carried out using special devices- steam needles made of metal pipes with a diameter of 250-500 mm, through which hot steam is introduced into the soil. Bottom part The steam needle is equipped with a metal tip containing many 2-3 mm holes. A rubber hose equipped with a tap is connected to the upper (hollow) part of the needle pipe. To install steam needles, wells are drilled in the ground (checkerboard pattern, distance 1000-1500 mm) with a length of 70% of the required thawing depth. Metal caps equipped with seals are placed on the holes of the well, through which a steam needle will be passed.

After installing the needles through the hose, steam is supplied to them under a pressure of 0.06-0.07 MPa. The surface of the thawed area of ​​land is covered with a layer of sawdust. Steam consumption for heating a cubic meter of soil is 50-100 kg; in terms of thermal energy consumption, this method is 1.5-2 times more expensive compared to heating with buried electrodes.

The method of thawing frozen soil using contact electric heaters is externally similar to steam defrosting. Heating elements with insulation from metal case needles. When connecting power a heating element transfers thermal energy to the body of the needle-pipe, and it to the layers of the soil. Thermal energy during heating it spreads radially.

UPGO SPECT are designed to solve a number of problems: heating of inert materials in winter, water heating and space heating.

We offer steam-gas heating installations that produce heating of inert materials for BSU (sand, crushed stone, gravel, limestone):

The numbers indicate the nominal thermal power installations in kilowatts.

The equipment is manufactured in accordance with our patent and certificate of conformity.

How do inert ones heat?

(Selection Guide).

The technology for producing concrete mixtures in winter is somewhat different from the technology for producing concrete in summer.

At low temperatures environment From -5°C and below several additional problems arise:

1. The temperature of the inert materials (sand, crushed stone) is such that conditions arise for the water to freeze during mixing, and the mixture does not turn out.
2. Heating is required in the premises of a concrete plant for comfortable work of personnel and units.
3. Ready concrete mixture must be delivered to construction site with a temperature not lower than 15°C. Mixers transporting concrete are also filled with water at a temperature of at least 40°C.

The first problem in mild frosts is partially solved by using antifreeze additives and heated water. Second, the use of electric heaters. The third problem cannot be solved without the use of special means.

What is required to produce concrete in winter?

1. Heating of inert materials (sand and crushed stone) to a temperature from 5°C to 20°C.
2. Heating water to a temperature from 40°C to 70°C.
3. Usage economical system space heating.

What energy sources are available for heating inerts and water?

Let's not consider exotic energy sources like wind generators, solar panels, thermal springs etc. Let us formulate the problem as follows:

Required to work at low temperatures;

There is no central heating system;

Using electricity is too expensive.

How to heat inert materials?

The most common energy sources are gas and diesel fuel, they work perfectly together with automation systems. It is possible to use fuel oil and heating oil. Firewood and coal are used less frequently due to the complexity of automation.

What equipment is used for heating inert materials?

The industry produces installations for heating sand, crushed stone, water, operating on various physical principles. The advantages and disadvantages of the installations are given below:

1. Heating of inert materials with hot air.

Fuel: diesel.

Advantages:

Air temperature up to 400 °C

Small dimensions;

Flaws:

Low efficiency (high energy consumption during operation, since the air does not effectively transfer heat to materials, most of the heat goes into the atmosphere);

Slow heating of inert materials (30-60 minutes);

Low air pressure does not blow through fine fractions and sand;

There is no heating of process water;

Not used for space heating.

2. Warming up inert materials with steam.

Fuel: diesel.

Advantages:

High efficiency;

High efficiency of heating of inert materials;

Quick heating of inert materials (10-20 minutes);

Average cost;

You can heat water;

Small dimensions;

Electric power up to 2 kW.

Flaws:

Create high humidity inert materials (due to steam condensation from 500 to 1000 kg per hour;

Highly efficient steam boilers with a temperature above 115 °C and a pressure of more than 0.7 kg/cm² are regulated;

Difficult to use for space heating (it turns off when the concrete plant is idle).

3. Heating of inert materials with registers hot water or ferry.

Fuel: diesel or central heating.

Advantages:

High efficiency;

Not complicated, cheap equipment;

No technical approval required;

You can heat water;

Can be used for space heating;

Very small dimensions;

Electric power up to 0.5 kW.

Flaws:

Frequently requires repair and maintenance of registers;

Low efficiency of heating of inert materials;

The heating process takes several hours.

4. Turbomatics (heating of inert air-steam mixture with heat exchangers).

Fuel: diesel.

Advantages:

High efficiency;

No technical approval required;

No registers;

You can heat the water.

Flaws:

Complex, expensive equipment;

Not used for space heating;

Large dimensions;

Electric power up to 18-36 kW (cyclically).

5. Steam-gas installations.

Heating of inert materials with flue gases.

Fuel: diesel.

Advantages:

High efficiency;

High efficiency of heating of inert materials (10-20 minutes);

Not complex equipment with an average cost;

No technical approval required;

No registers;

Mixture temperature up to 400 °C.

Can be used for space heating (there is a standby mode);

There is water heating for technological needs and refilling mixers;

Small dimensions.

Flaws:

Electric power up to 18 kW (cyclically).