Technical description of type de boilers. DE series steam boilers
PURPOSE OF THE PRODUCT
DE boilers are double-drum, vertical-water-tube boilers designed to produce saturated or slightly superheated steam used for technological needs industrial enterprises, in heating, ventilation and hot water supply systems.
The main technical characteristics of the DE-16-14GMO boiler are given in the table.
Price
RUB 4,800,000
Model specifications
| Boiler | DE-16-14GMO | Steam capacity, t/h | 16 |
|---|---|
| Operating pressure(excess) steam at the outlet, MPa (kg/cm?) | 1,3 (13) | Temperature of superheated steam at the outlet, ? C | 194 |
| Feed water temperature, ? C | 100 | Estimated efficiency (gas), % | 93 |
| Estimated efficiency (fuel oil), % | 90 | Estimated fuel consumption (gas), m?/h | 1141 |
| Estimated fuel consumption (fuel oil), m?/h | 1088 | Total heating surface of the boiler, m? | 193 |
| Superheater heating surface | - | Boiler water volume, m? | 13,3 |
| Steam volume of the boiler, m? | 2,3 | Water supply in water indicator glass at max. level, min | 3,9 |
| Total number of convective bundle tubes, pcs. | 532 | Dimensions of transportable unit, LxWxH, mm | 7180x3030x4032 |
| Layout dimensions, LxWxH, mm | 8655x5240x6072 | Boiler length (with stairs and platforms), mm | 6478 |
| Boiler width, mm | 4300 | Boiler height, mm | 5050 |
| Weight of transportable boiler block, kg | 19130 | Boiler weight in the factory delivery volume, kg | 20750 |
| Basic kit assembled | Boiler block with casing and insulation, stairs, platforms, burner GM-10 | Additional equipment: |
| Economizer | BVES-IV-1 | Economizer | EB1-330 |
| Fan | VDN-9-1500 | Smoke exhauster | DN-11.2-1500 |
| Box No. 1 | Fittings for boiler DE-16-14GMO | Box No. 2 | Safety devices for boiler DE-16-14GMO |
PRODUCT DESCRIPTION
The combustion chamber of boilers is located on the side of the convective beam, equipped vertical pipes, flared in the upper and lower drums. The width of the combustion chamber along the axes of the side screen pipes is the same for all boilers - 1790 mm. Combustion chamber depth: 1930 - 6960 mm. Main components boilers are upper and lower drums, a convective beam, front, side and rear screens that form the combustion chamber.
The pipes of the gas-tight partition and the right side screen, which also forms the ceiling of the combustion chamber, are inserted directly into the upper and lower drums. The ends of the rear screen pipes are welded to the upper and lower collectors Ф 159х6 mm. The front screen pipes of the DE-16-14GMO boiler are flared in the upper and lower drums.
In all standard sizes of DE boilers, the diameter of the upper and lower drums is 1000 mm. The distance between the axes of the drums is 2750 mm (the maximum possible under the conditions of transporting the block by rail). Length of the cylindrical part of the boiler drums with capacity
10 t/h - 6000 mm. For access to the inside of the drums, there are manhole gates in the front and rear bottoms of each of them. Drums for boilers with operating absolute pressure of 1.4 and 2.4 MPa (14 and 24 kgf/cm 2) are made from steel sheet in accordance with GOST 5520-79 from steel grades 16GS and 09G2S GOST 19281-89 and have a wall thickness of 13, respectively and 22 mm.
In the water space of the upper drum there is a feed pipe and a pipe for introducing phosphates, and in the steam volume there are separation devices. The lower drum contains a device for steam heating of water in the drum during kindling and pipes for draining water; for boilers with a capacity of 16 t/h, there are perforated pipes for periodic purging.
Boilers with a steam capacity of 16 t/h use two-stage evaporation. The second evaporation stage includes the rear part of the furnace screens and part of the convective beam, located in the zone with a higher gas temperature. The second stage evaporation circuits have an unheated downdraft system.
The convective beam is separated from the combustion chamber by a gas-tight partition, in the rear part of which there is a window for the entry of gases into the beam. The partition is made of pipes Ø 51x2.5 mm placed closely with a pitch of 5 = 55 mm and welded together. When inserted into drums and pipes, they are separated into two rows. The distribution points are sealed with metal spacers and chamotte concrete. The convective bundle is formed by vertical pipes Ø 51 x 2.5 mm arranged in a corridor, flared in the upper and lower drums. The pitch of the pipes along the drum is 90 mm, the transverse pitch is 110 mm (except for the average pitch, which is 120 mm).
DE-16-14GMO boilers do not have stepped partitions in the bundle, but required level gas velocities are maintained by changing the beam width from 890 to 1000 mm. Flue gases pass across the entire cross-section of the convective beam and exit through the front wall into the gas box, which is located above the combustion chamber, and through it they pass to the economizer located at the rear of the boiler.
All boiler sizes have the same circulation scheme. The contours of the side screens and the convective beam of all standard sizes of boilers, as well as the front screen of boilers with a steam capacity of 16 t/h, are closed directly to the drums; the contours of the rear screen of all boilers are connected to the drum through intermediate collectors: the lower one is distributing (horizontal) and the upper one is collecting (inclined). The ends of the intermediate collectors on the side opposite to the drums are united by an unheated recirculation pipe Ф 76 x 3.5 mm.
As primary separation devices The first stage of evaporation uses guide shields and canopies installed in the upper drum to ensure the delivery of the steam-water mixture to the water level. A horizontal louvered separator and a perforated sheet are used as secondary separation devices of the first stage of the DE-16-14GMO boiler. The separation devices of the second stage of evaporation are longitudinal shields that ensure the movement of the steam-water mixture, first to the end, and then along the drum to the transverse partition separating the compartments. The staged evaporation compartments communicate with each other via steam through a window above the transverse partition, and via water through a feed pipe Ø 89 - 108 mm, located in the water volume.
On boilers with a capacity of 16 t/h, the superheater is vertical, drained, made of two rows of pipes Ø 51x2.5 mm, the outer row pipes when entering the collectors Ø 159 mm are cased to Ø 38 mm.
Dense shielding of the side walls (relative pitch of the pipes a = 1.08), ceiling and bottom of the combustion chamber makes it possible to use light insulation on boilers in two to three layers of insulating boards with a total thickness of 100 mm, laid on a layer of fireclay concrete on a grid 15-20 mm thick. For DE-16-14GMO boilers, the front wall lining is made of fireclay bricks 125 mm thick and several layers of insulating boards 175 mm thick, the total thickness of the front wall lining is 300 mm. The lining of the rear wall consists of a layer of fireclay bricks 65 mm thick and several layers of insulating boards 200 mm thick; the total thickness of the lining is 265 mm. To reduce suction into the gas path of the boiler, the insulation is covered from the outside with metal sheet cladding 2 mm thick, which is welded to the frame. Cut sheathing sheets are supplied by the factory in packages. The use of pipe lining with a tight pipe pitch can improve the dynamic characteristics of boilers and significantly reduce heat losses to the environment, as well as losses during start-ups and shutdowns.
Standard cast iron economizers EB, proven by long-term operating experience, are used as tail heating surfaces of boilers.
The boilers are equipped with stationary blowers located on the left side of the boiler. For blowing boilers, saturated or superheated steam with a pressure of at least 0.7 MPa (7 kgf/cm2) is used.
All boilers have a support frame to which the mass of the boiler elements operating under pressure, the mass of boiler water, as well as the mass of the piping frame, pipe lining and lining are transferred. The fixed supports of the boilers are the front supports of the lower drum. The middle and rear supports of the lower drum are movable and have oval holes for bolts that are attached to the support frame during transportation.
Each boiler E (DE) is equipped with two spring safety valves, one of which is the control. On boilers without a superheater, both valves are installed on the upper drum of the boiler and any of them can be selected as a control valve; on boilers with a superheater, the control valve is the valve of the superheater outlet manifold.
Nominal steam output and steam parameters corresponding to GOST 3619-89,
are provided at a feed water temperature of 100°C when burning fuels: natural gas With specific heat combustion 29300 - 36000 kJ/kg (7000 - 8600 kcal/m3) and fuel oil grades 40 and 100 according to GOST 10588-75.
The control range is from 20 to 100% of the nominal steam output. Short-term operation with a load of 110% of the rated steam output is allowed. Maintaining the superheat temperature in boilers with steam superheaters is ensured in the load range of 70-100%
DE-16-14GMO boilers can operate in the pressure range of 0.7-1.4 MPa (7-14 kgf/cm2). With a decrease in operating pressure, the boiler efficiency does not decrease.
In boiler houses designed to produce saturated steam without imposing strict requirements on its quality, the steam production of DE type boilers at pressures reduced to 0.7 MPa (7 kgf/cm2) can be taken the same as at a pressure of 1.4 MPa ( 14 kgf/cm 2).
For type E (DE) boilers, the throughput of the safety valves corresponds to the rated output of the boiler at an absolute pressure of at least 0.8 MPa (8 kgf/cm2). If the heat-using equipment connected to the boiler has a maximum operating pressure less than the above values, additional safety valves should be installed on it to protect this equipment. When operating at reduced pressure, safety valves on the boiler and additional safety valves installed on the equipment must be adjusted to the actual operating pressure.
With a decrease in pressure in boilers to 0.7 MPa (7 kgf/cm2), changes in the configuration of boilers with economizers are not required, since in this case the underheating of water in feed economizers to the steam saturation temperature in the boiler is more than 20 ° C, which satisfies requirements of Rostechnadzor rules.
Boilers are supplied in assembled form one transportable unit, including upper and lower drums with intra-drum devices, a pipe system of screens and a convective beam (if necessary, a superheater), a support frame, a piping frame, casing, insulation, and a burner.
The main elements of boilers are:
1.Upper and lower drums;
3.The left combustion screen is gas-tight;
5. The right combustion screen, the pipes of which are made in the form and overlap the ceiling and bottom part fireboxes (under);
5.Front screen;
6.Rear screen;
7.Two manifolds of the rear combustion screen, made 0 159 * 6 mm;
8. Convective tube bundle;
9. Brickwork;
10.Metal frame;
11.Metal casing;
12.Headset;
13.Fittings;
14.Control and measuring instruments;
15. Three lower pipes, 0 159 * 6 mm for boilers with a steam capacity of up to 16 t/h and 0 219 * 6 mm for DE-25-14 boilers;
16. Recirculation pipe of the rear screen;
17.The blowing device is located on the left side of the convective beam;
18. Boiler piping.
The boiler drums are made of high-quality steel grade 16 GS, inner diameter 1000 mm. The thickness of the drum walls is 13 mm. The convective beam is made along the entire length of the drums from pipes with a diameter of 51ˣ2.5 mm. The left combustion screen is made of pipes 0 51*4 mm. The right combustion screen, front and rear screens are made of pipes d = 51˟2.5 mm. Two rear screen collectors are made of pipes d = 159ˣ6 mm. The recirculation pipe is made of a pipe with a diameter of 76ˣ3.5 mm. Three down pipes with a diameter of 259ˣ6 mm (boilers DE-25-14).
The length of the cylindrical part of the drums increases from 2250 mm for DE-4-14 boilers to 7500 mm for DE-25-14 boilers. The center-to-center distance of the drums is 2750 mm. For access to the inside of the drums, there are manholes in the front and rear bottoms of the drums.
The width of the convective beam is 890 mm for boilers 4; 6.5 and 16 tons of steam and 1000 mm for boilers with a steam capacity of 10 and 25 tons of steam per hour.
The pitch of the convective bundle pipes along the drums is 90 mm, transverse - 110 mm. The middle row of convective bundle pipes along the axis of the drums has a pitch of -120 mm. The pipes of the outer row of the convective bundle have a longitudinal pitch of -55 mm. At the entrance to the drums, the pipes are separated into two rows.
In convective bundles of boilers with a steam capacity of 4; 6.5 and 10 tons of steam per hour to ensure the required speeds flue gases longitudinal steel partitions are installed
Boilers with a steam capacity of 16 and 25 tons of steam per hour do not have partitions in the convective beam, and the speed of movement of the flue gases is maintained by changing the width of the convective beam (1000 mm).
The convective beam is separated from the combustion chamber by a gas-tight left combustion screen. Gas tightness is ensured by registering metal plates between the pipes along their entire height from the lower drum to the upper drum.
In the rear part of the left combustion screen, metal plates (spacers) are not installed; the pipes of the rear part of the convective bundle are made in a corridor and form “windows” for the flow of flue gases from the furnace into the convective bundle.
The areas where the screen pipes are routed at the entrance to the drums are compacted with chamotte concrete.
The pipes of the right combustion screen form the bottom and ceiling of the firebox.
Front screen pipes in the amount of 4 or 2 (various modifications of boilers) border the burner embrasure on the right and left and are inserted into the upper and lower drums (see in the figure).
Boiler DE-25-14 GM (Rear view)
The cross-section of the combustion chamber is the same for all boilers. The average height of the combustion chamber is 2400 mm, width 1790 mm. The depth of the combustion chamber increases with increasing boiler steam production from 1930 mm for DE-4-14 boilers to 6960 mm for boilers with 25 tons of steam per hour.
The main part of the pipes of the convective bundle, the right combustion screen, as well as the pipes of the front screen are connected to the drums by flaring.
The pipes of the gas-tight partition, as well as part of the pipes of the right combustion screen and the outer row of the convective beam, are welded to the drums by electric welding.
The pipes of the rear furnace screen are welded to the lower and upper collectors 0 159 * 6 mm. The collectors, in turn, are welded to the upper and lower drums.
The ends of the collectors on the side opposite the drums are connected by an unheated recirculation pipe 0 76 * 3.5 mm.
On all boilers, to protect against overheating on the combustion side of the recirculation pipe and the collectors and pipes of the rear screen, two tubes 0 51 * 2.5 mm are installed in the combustion chamber, connected to the drums by flaring (see Fig. No. 2, page 6).
DE boilers with a steam capacity of up to 10 t/h have four circulation circuits:
Water circulation circuit of the convective beam and the left combustion screen;
Circulating water circuit of the right combustion screen;
Front screen water circulation circuit;
Water circulation circuit of the rear combustion screen.
In boilers DE-16-14 and DE-25-14, which have partitions inside the drums and 2-stage evaporation, water circulation is much more complicated.
Boilers with steam capacity 4; 6.5 and 10 tons of steam per hour work with single-stage evaporation. In boilers with a steam capacity of 16 and 25 tons of steam per hour, 2-stage evaporation is used. For these purposes, the drums are made metal partitions dividing the drums into two compartments: a large compartment - finishing and a small compartment - salt. In the upper drum, the partition is not continuous, that is, it does not cover the entire diameter of the drum.
A solid partition is installed in the lower drum.
In the second stage of evaporation, using transverse partitions in the drums, the following are placed:
Rear part of the left and right firebox screens;
Rear screen;
Part of a convective bundle of pipes located in an area with higher flue gas temperatures.
The second stage of the upper drum is supplied with water through an overflow pipe 0133 mm long, at least 2 meters long, passing through the dividing partition of the upper drum.
The second stage evaporation circuit has three lower unheated pipes 0159*6 mm, for DE boilers with a steam capacity of up to 16 tons of steam per hour and 0219*6 mm for DE-25-14 boilers.
The drainage system of the salt compartment circuit consists of unheated pipes. The downward system of the first stage of evaporation consists of the last rows of convective bundle pipes along the gas flow.
The steam volume of the upper drum contains separation devices: a perforated metal sheet and plate separators.
In the water volume of the upper drum there is a feed pipe and a pipe for introducing chemical reagents. Guide shields and visors for cleaning steam from hardness salts.
The upper drum of the boiler also contains stilling columns and impulse tubes from the finishing and salt compartments to the water level indicators.
Water level indicators are attached to pipes ( impulse pipes) coming from the steam and water volumes from the finishing and salt compartments of the upper drum.
TECHNICAL DESCRIPTION DE TYPE BOILERS
Purpose, technical data and design of DE type boilers
DE steam boilers are designed to produce saturated or superheated steam used for the technological needs of industrial enterprises, as well as heating, ventilation and hot water supply systems.
The main characteristics and parameters of the boilers are given in Table 1.
Double-drum vertical water-tube boilers are made according to the design diagram “D”, characteristic feature which is the lateral location of the combustion chamber relative to the convective part of the boiler.
The main components of the boilers are the upper and lower drums, the convection beam and the left combustion screen (gas-tight partition), the right and rear combustion screens that form the combustion chamber, as well as the screening pipes for the front wall of the furnace.
In all standard sizes of boilers, the internal diameter of the upper and lower drums is 1000 mm. The length of the cylindrical part of the drums increases with increasing boiler steam production from 2250 mm for 4 t/h boilers to 7500 mm for 25 t/h boilers. The distance between the drum axes is 2750 mm.
The drums are made of sheet steel grade 16GS GOST5520-79 with a thickness of 13 and 22 mm for boilers with an operating absolute pressure of 1.4 and 2.4 MPa, respectively (14 and 24 kgf/cm 2 ).
For access to the inside of the drums, there are manholes in the front and rear bottoms.
The convective beam is formed by vertical pipes Ø51x2.5 mm located along the entire length of the cylindrical part of the drums, connected to the upper and lower drums.
The width of the convective beam is 1000 mm for boilers with a steam capacity of 10; 25 t/h and 890 mm - for other boilers.
The longitudinal pitch of the convective bundle pipes is 90 mm, the transverse pitch is 110 mm (except for the average pitch located along the axis of the drums, equal to 120 mm). The pipes of the outer row of the convective bundle are installed with a longitudinal pitch of 55 mm; When entering the drums, the pipes are separated into two rows of holes.
In convective bundles of boilers 4; 6.5 and 10 t/h, longitudinal cast iron or stepped steel partitions are installed. Boilers 16 and 25 t/h do not have partitions in the bundle.
The convective beam is separated from the combustion chamber by a gas-tight partition (left combustion screen), in the rear part of which there is a window for gases to enter the beam.
The pipes of the gas-tight partition, the right side screen, which also forms under the ceiling of the combustion chamber, and the pipes of the front wall screening are inserted directly into the upper and lower drums.
The cross-section of the combustion chamber is the same for all boilers. Its average height is 2400 mm, width – 1790 mm. The depth of the combustion chamber increases with increasing boiler steam production from 1930 mm for DE - 4 t/h to 6960 mm for DE - 25 t/h.
|
Factory designation of standard sizes |
Paro productivity, t/h |
Boiler operating pressure MPa (kgf/cm2) |
State or temperature of steam, °C |
Total heating surface, m 2 |
Boiler water volume, m 3 |
Steam volume of the boiler, m 3 |
Dimensions of the transportable unit |
Boiler dimensions by boiler cell |
Weight of transportable boiler block, kg |
Boiler weight as supplied by the plant, kg |
Type of gas and oil burner |
Estimated fuel consumption for separate combustion |
Accessories |
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economizer |
fan |
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Fuel oil, kg/h |
Gas, m 3 / h |
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DE-4-14GM-O/R / |
saturated |
EB2-94I (BVES-1-2) |
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|
DE-4-14-225GM-O |
overheated 225(+25;-10) |
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|
DE-6.5-14GM-O/R / |
saturated |
EB2-142I (BVES-2-2) |
VDN-11.2-1000 |
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DE-6.5-14-225GM-O |
overheated 225(+25;-10) |
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DE-10-14GM-O/R / |
saturated |
EB2-236I (BVES-3-2) |
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DE-10-14-225GM-O |
overheated 225(+25;-10) |
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DE-10-24GM-O |
saturated |
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DE-10-24-250GM-O |
overheated 250(+25;-10) |
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DE-16-14GM-O/R / |
saturated |
EB2-330I (BVES-4-1) |
VDN-11.2-1500 |
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DE-16-14-225GM-O |
overheated 225(+25;-10) |
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DE-16-24GM-O |
saturated |
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DE-16-24-250GM-O |
overheated 250(+25;-10) |
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DE-25-14GM-O/R / |
saturated |
EB2-808I (BVES-5-1) |
VDN-11.2-1500 |
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DE-25-14-225GM-O |
overheated 225(+25;-10) |
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DE-25-15-270GM-O |
overheated 270(+25;-10) |
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DE-25-15-285GM |
overheated 285(+25;-10) |
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|
DE-25-24GM-O |
saturated |
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DE-25-24-250GM-O |
overheated 250(+25;-10) |
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|
DE-25-24-380GM-O |
overheated 270(+25;-10) |
VDN-12.5-1500 |
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Table 1
To the table
The minimum steam load of boilers, depending on the state of the burner, is 20-30% of the calculated one.
The maximum steam load of boilers, taking into account sufficient blast and draft (short-term) for boilers DE-4-10GM-120% of the calculated one; for boilers DE16-25GM-110% of the calculated value.
Feed water temperature - 100°C (+10; -10).
The temperature of the blast air in front of the burner is not lower than 10°C.
The letter “O” in the factory designation of boilers means: a boiler with casing and insulation.
When equipping boilers operating on fuel oil with a steel economizer, in order to increase the service life of the latter, it is necessary to provide additional feedwater heaters that ensure heating of the water in front of the economizer to 130°C (to increase the temperature of the wall of the economizer coils). This is due to the low-temperature, sulfurous corrosion that occurs under these conditions, which occurs intensively when sulfurous acid condenses onto colder metal walls below the dew point.
The plant can equip boilers with a steam capacity of 4; 10 t/h compact steel economizers supplied as one unit with the boiler and feedwater heaters installed in the lower drum.
The pipes of the right combustion screen Ø51x2.5 mm are installed with a longitudinal pitch of 55 mm; When entering the drums, the pipes are separated into two rows of holes.
The shielding of the front wall is made of pipes Ø51x2.5 mm.
The gas-tight partition is made of pipes Ø51x2.5 mm or Ø51x4 mm, installed at 55 mm intervals. At the entrance to the drums, the pipes are also separated into two rows of holes. The vertical part of the partition is sealed with metal spacers welded between the pipes. Pipe distribution areas at the entrance to the drums are sealed by welding to the pipes metal plates and chamotte concrete.
The main part of the pipes of the convective bundle and the right furnace screen, as well as the shielding pipes of the front wall of the furnace, are connected to the drums by rolling. To increase the strength of the rolling joints, one annular recess is rolled into the walls of the holes drilled for the pipes being rolled. When rolling, the metal of the pipe fills the recess, creating a labyrinth seal.
Pipes of the gas-tight partition are connected to the drums by electric welding or rolling: part of the pipes of the gas-tight partition, the right combustion screen and the outer layer of the convective beam, which are installed in holes located in the welds or heat-affected zone, are attached to the drum by electric welding or rolled.
The design of the rear firebox screen is possible in two versions:
1. Pipes of the rear furnace screen Ø51x2.5 mm, installed with a pitch of 75 mm, are welded to the upper and lower screen collectors Ø159x6 mm, which in turn are welded to the upper and lower drums.The ends of the rear screen collectors on the side opposite the drums are connected by an unheated recirculation pipe Ø76x3.5 mm; to protect the recirculation pipes and collectors from thermal radiation, two pipes Ø51x2.5 mm are installed at the end of the combustion chamber, connected to the drums by rolling.
2. C-shaped pipes Ø51x2.5 mm, forming the rear screen of the firebox, are installed in increments of 55 mm and connected to the drums by rolling.
Boiler superheaters 4; 6.5 and 10 t/h are made of coils from pipes Ø32x3 mm.
The superheater is a single-stage one, installed behind the first part of the convective beam at the point where the convective flue turns. Saturated steam from the upper drum is directed by one bypass pipe to the upper inlet manifold of the superheater Ø159x6 mm. The superheated steam exits from the lower collector.
On boilers of 16 and 25 t/h at a pressure of 1.4 and 2.4 MPa with steam superheating of 225°C and 250°C, the superheaters are vertical, made of two rows of pipes Ø51x2.5 mm. The outer row of pipes when entering the Ø159x6 mm collectors are cased up to Ø38 mm. The two-stage superheater is located at the beginning of the convective beam (opposite the exit window from the furnace). The outer row of the superheater, made of cased pipes, simultaneously serves as part of the enclosing wall of the boiler block. Saturated steam from the upper drum is directed by bypass pipes Ø108x4.5 mm to the upper manifold of the first superheating stage, located second along the gas flow. Having passed the pipes of the first stage, the lower manifold Ø159x6 mm and the pipes of the second stage of superheating, the steam is supplied to the outlet of the manifold Ø159x6 mm.
The steam superheater of the DE-25-24-380 GM boiler is made of coil pipes Ø38x3 mm, two-stage and is located at the beginning of the convective beam across the entire width of the flue. To regulate superheat, a surface desuperheater located in the lower drum of the boiler and two control valves are used.
Saturated steam from the upper drum is directed by bypass pipes Ø108x4.5 mm to the upper manifold of the first superheating stage (second along the gas flow). Having passed through the coils and the first stage, steam from the lower outlet of the collector is directed either by two pipes Ø108x4.5 mm to the desuperheater, or by one pipe Ø108x4.5 mm to the lower collector of the second stage of superheating (the first in the flow of gases).
Having passed the second stage, the steam is supplied to the outlet through the upper manifold. The superheater collectors are made of pipes Ø159x6 mm.
Boilers with steam capacity 4; 6.5 and 10 t/h are made with a single-stage evaporation scheme. In boilers 16; 25 t/h – two-stage evaporation scheme. The second stage of evaporation, using transverse partitions in the drums, includes the rear part of the left and right furnace screens, the rear screen and part of the convective beam located in the zone with a higher gas temperature.
The second stage of evaporation is fed from the first stage through a Ø108 mm bypass pipe passing through the transverse partition of the upper drum. The circuit of the second stage of evaporation has unheated downpipes Ø159x4.5mm.
Lowering link of circulation circuits of boilers 4; 6.5 and 10 t/h, and the first stage of evaporation of boilers 16 and 25 t/h are the last least heated rows of convective bundle pipes along the gas flow.
IN water space The upper drum contains a feed pipe and fenders, and in the steam volume there are separation devices.
The lower drum contains a device for steam heating of water during kindling, a perforated purge pipeline and pipes for draining water.
As primary separation devices, fender shields and guide visors installed in the upper drum are used, ensuring the supply of the steam-water mixture to the water level. A perforated sheet and a louvered separator are used as secondary separation devices.
The fender shields, guide visors, louvered separators and perforated sheets are made removable to allow complete inspection and repair of the rolling connections of the pipes with the drum and the drum itself. All separation devices are attached to half-clamps welded to the drum using studs and nuts. Disassembly and assembly of louvered separators and perforated sheets is carried out element by element. Dismantling of fender shields begins with the lower shield. Assembly of separation devices is carried out in the reverse order.
When assembling steam separation devices, you should pay attention to creating a tightness in the places where the fender panels are connected to each other and in the places where they are attached to the half-clamps, as well as in the places where the guide visors are connected to the strip with studs: install new paronite gaskets, lubricated with graphite.
If it is necessary to adjust the water chemistry of boilers, the introduction of phosphates should include a line between the economizer and the boiler.
On boilers with steam capacity 4; 6.5 and 10 t/h, continuous blowing is provided from the lower collector of the rear screen (in the case when the rear screen has a collector). On boilers with steam capacity 4; 6.5 and 10 t/h in which the rear furnace screen is made of C-shaped Ø51 mm, periodic blowing of the boilers is combined with continuous blowing, carried out from the front bottom of the lower drum: it is recommended to insert the periodic blowing pipeline in the gap between the shut-off and regulating body on the line continuous blowing.
Boilers with a steam capacity of 16 and 25 t/h have continuous blowing from the second evaporation stage (salt compartment) of the upper drum and periodic purging from the clean and salted compartments of the lower drum and the lower collector of the rear screen (in the case where the rear screen has a collector).
Flue gas output from boilers with steam capacity 4; 6.5 and 10 t/h are carried out through a window located on the rear wall of the boiler. On boilers with a steam capacity of 16 and 25 t/h, the exit of flue gases is through a window in the left side wall of the boiler at the end (along the gas flow) of the convective beam.
To clean the outer surface of the convective beam pipes from deposits, the boilers are equipped with stationary blowers or a wave generator (GUV).
The blower has a pipe with nozzles that must be rotated when blowing. The outer part of the apparatus is attached to the casing of the left convective wall of the boiler. The blower pipe is rotated manually using a flywheel and chain.
For blowing, saturated or superheated steam from operating boilers is used at a pressure of at least 0.7 MPa.
The shock wave generator, like gas-pulse cleaning (GCP), is a representative of the shock wave cleaning method, based on the interaction of contaminated heating surfaces with a shock wave and a high-speed flow of combustion products that are formed during the combustion of a powder charge.
The portable device weighing 17 kg consists of a shock wave generator itself with a remote trigger, corresponding barrel and powder charge.
To carry out activities using this cleaning method, boilers are equipped with special pipes and installation platforms (attachment points to the casing).
To remove soot deposits from the convective beam, hatches are installed on the left wall of the boiler.
All boilers have three peeper hatches - two on the right side and one on the rear walls of the combustion chamber.
The opening into the firebox can be the hole of the explosion valve or the burner lance.
Explosion valves on boilers 4; 6.5; 10 t/h are located at the front of the boiler. On boilers of 16 and 25 t/h there are three explosion valves - one on the front wall and two on the boiler flue.
Boilers are manufactured at the factory in the form of one transportable unit, mounted on a support frame and including: drums, pipe system, superheater (for boilers with superheated steam), frame, insulation and casing.
Boilers can also be manufactured as a block without factory-installed insulation and cladding: in this case, the insulation and cladding of the boiler block is carried out during installation in the manner described below.
Dense shielding of the side walls (relative pitch of pipes S = 1.08), ceiling and bottom of the combustion chamber allows the use of light insulation 100 mm thick on boilers, laid on a layer of fireclay concrete 15-20 mm thick, applied over a grid. Asbestos-vermiculite slabs or those with thermophysical properties equivalent to them are used as insulation.
The lining of the front wall is made of refractory fireclay bricks of class A or B, diatomaceous brick, insulating boards, lining back wall– made of fire-resistant fireclay bricks and insulating boards.
To reduce air suction, the insulation on the outside is covered with metal sheeting 2 mm thick, which is welded to the frame.
The plant does not supply brickwork and insulation materials.
Technical documentation for insulation implementation for design organizations and customers.
Boiler blocks, in the marking of which the last letter is O, are manufactured and supplied by the plant in insulation and casing.
As insulation on these boilers, mullite-silica felt MKRV-200 GOST 23619-79 is used and mineral wool increased temperature resistance TU36.16.22-31-89, laid between dense enclosing heating surfaces and the boiler casing.
To seal inter-pipe gaps at the entrance to drums, in explosion valves, burner flanges, manhole covers and other components, asbestos cardboard KAON-1-5 GOST 2850-80 and asbestos cord SHAON 22 GOST 1779-83 are used.
Sheathing sheets for blocks supplied insulated have a thickness of 3 mm, 2 mm for boilers supplied without insulation, and are welded along the entire contour of the junction to the frame elements.
More information about the insulation (lining) of boilers is described in the sections devoted to the installation and repair of boilers.
The support frame takes the load from the boiler elements operating under boiler water pressure, as well as the frame, insulation and cladding.
The load from the boiler pressure elements and boiler water is transferred to the support frame through the lower drum.
To install the lower drum, the design of the support frame includes front and rear transverse beams with support pads, as well as supports - two to the right of the drum (from the firebox side) on the transverse beams and two to the left of the drum on the longitudinal beam.
The lower drum at the front of the boiler is fixed motionless by welding the drum to the transverse beam of the support frame through a ring and fixed supports. The frame and casing from the front of the boiler are also fixedly attached to the lower drum. Thermal expansion of the drum is provided towards the rear bottom, for which the rear supports are made movable. A benchmark is installed on the rear bottom of the lower drum to control the thermal expansion of the drum (boiler). Installation of benchmarks to control the thermal expansion of boilers in the vertical and transverse directions is not required, since the design of the boilers ensures thermal movement in these directions.
To burn fuel oil and natural gas, gas and oil burners GMP and GM are installed on the boilers (Table 1).
The main components of the burners are gas part, a blade apparatus for swirling air, a nozzle assembly with main and backup steam-mechanical nozzles and flaps used to close the holes of the removed nozzle.
At the front of the burner, a peephole and an ignition-protective device are installed.
The combustion chamber for two-stage fuel combustion, installed on 25 t/h boilers, includes a housing, inner and outer shells and a tangential air swirler.
Fuel in full quantity supplied to the GMP-16 burner installed at the front of the combustion chamber for two-stage fuel combustion. There, through the annular slot formed by the outer casing and the inner shell of the combustion chamber, primary air is supplied (70% of the total amount of air required for complete fuel combustion), secondary air (30% of the total) enters through the annular slot and the tangential swirler of the chamber. The directions of rotation of primary and secondary air are the same.
The combustion chamber of two-stage fuel combustion is protected from torch radiation by fire-resistant fireclay masonry of class “A”.
The embrasure of the GMP-16 burner is of a conical type with an opening angle of 35° to one side, while that of the GM-10, GM-7, GM-4.5 and GM-2.5 burners is of a conical type with an opening angle of 25° to one side.
The GM-7, GM-4.5 and GM-2.5 air burners are vortex, the GM-10 burner is direct-flow vortex.
The boilers are earthquake-resistant under seismic impacts of up to 9 points (on the MSK-64 scale) inclusive.
The design of boilers is constantly being improved, so individual components and parts may differ slightly from those described in
instructions.
FITTINGS, CONTROL INSTRUMENTS AND SAFETY DEVICESDE TYPE BOILERS
Each boiler is equipped with two spring safety valves.
On boilers without a superheater, both valves are installed on the upper drum of the boiler.
On boilers with a superheater, one valve is installed on the drum, the second - on the outlet manifold of the superheater.
The valves are adjusted in accordance with the instructions in the corresponding section of the “Installation Instructions”.
The boilers are equipped with two direct-acting water level indicators, which are connected to pipes communicating with the steam volumes of the upper drum.
In boilers with a steam capacity of 16 and 2.5 t/h with a two-stage evaporation scheme, one of the water level indicators is connected to the clean compartment, the second to the salty one.
Installation of signs and their maintenance are carried out in accordance with the accompanying technical documentation of the plant and the Boiler Rules (section 6.3).
The boilers are equipped with the required number of pressure gauges and fittings. ..
Boilers steam series DE are two-drum, vertical water-tube devices with natural circulation, a D-shaped combustion chamber and a convective beam placed parallel to the combustion chamber.
Such devices are supplied in one transportable unit (boiler in casing and insulation with a supplied burner; an integrated version is possible), complete with instrumentation, fittings, as well as fittings, stairs, platforms, and a steam superheater.
Design and advantages of DE boilers
DE series boilers have the following advantages:
- Reliability in operation and increased service life.
- Quite high efficiency - up to 93%.
- Possibility of operation in steam generation and water heating modes.
- The boiler is transportable, supplied on one block, simply installed and connected to utilities.
DE series equipment consists of 2 drums (upper and lower), a pipe system, and additional components. Economizers are used as heating planes.
By agreement with the customer, all boilers are equipped with domestic or foreign burners. DE modifications intended for use with gaseous fuel can be equipped with a heating surface cleaning system.
The combustion chamber is located on the side of the convective beam, equipped with vertical pipes flared in both the upper and lower drums.
Composition of the combustion unit: convective beam, front, side and rear screens. The convective beam is separated from the combustion chamber by a gas-tight partition; in its rear part there is a window designed for the direct entry of gases into the beam.
To ensure that gas velocities are maintained directly in the convective beams, longitudinal stepped bulkheads are installed.
Thus, flue gases, passing completely across the entire cross-section of the convective beam, exit through the front wall into a box located above the combustion chamber, and flow through it to.
Gas-oil steam boilers of the DE series belong to the type of double-drum vertical water-tube devices and are designed for the industrial production of saturated steam, the pressure of which is 1.4 MPa and the temperature is 194°C.
Thus, DE 25 devices are used to produce steam used for technological work industrial companies; as heating equipment; in ventilation and hot water supply systems.
The DE 25 14 steam boiler has the following components: upper and lower drums with a diameter of 1000 mm, a convective beam and a combustion chamber located on the side of the convective part of the device along the convective beam.
At the same time, the distance between the axes of the drums for all standard sizes is the same, and an increase in steam production up to 25 t/h is achieved by increasing the length of the drums, combustion chamber, and also the convective beam.
Equipment DE 10 14 and DE 4 14
Let's look at what the marking “steam boiler DE 10 14 250GM” means:
10 – power, 10 tons of steam/hour.
14 – pressure, 1.4 MPa.
250 – temperature of heated steam, 250 `C
GM – picture of fuel: GM – liquid fuel (gas, fuel oil, etc.).
Such steam installations are supplied as a single transportable unit in special lining and casing. The delivery set includes a gas-oil burner, fittings within the boiler, stairs, and a platform.
The DE 4 14 steam boiler, whose steam output is up to 4 t/h, has a diameter of the upper and lower drums of 700 mm, other types - 1000 mm. The distance between the drums is 1700 and 2750 mm (the maximum allowable according to the requirements for transporting the block). For direct access to the inside of the drums, there are manhole gates in the front and rear bottoms.
Characteristics of steam boiler DE 16 14
The steam boiler DE 16 14 has a two-stage steam generation scheme. The second stage includes the back part of the camera screens, as well as part of the convective beam located in the zone with highest temperature gases The circuits of the two-stage steam generation circuit have an unheated system. In devices with a capacity of 16 t/h, the superheater is vertical, drained from two lines of pipes.
When choosing a heating equipment supplier, you need to pay attention to the range of work provided.Since it is very convenient if the supplier has the opportunity to offer design work, installation and subsequent maintenance of equipment.