Boiler Retra-4M 3000 kW

Boiler Retra-4M 3000 kW

Based on many years of experience, our specialists have developed and implemented the production of the Retra-4M industrial boiler with a capacity of 3000 kW, adapted for automatic operation (pellets from various types of wood, straw, peat, sunflower husks, coal with a fraction of up to 25 mm, wood chips, sawdust, husks, etc.).

Purpose

Boiler units with microprocessor control of coolant temperature, forced air supply control, automated fuel supply and mechanized ash removal are designed for heating residential and industrial buildings equipped with heating systems with forced circulation of coolant.

The minimum operating load of the boiler is 50% of the rated capacity.

The boiler unit operates with forced circulation of the coolant with an operating pressure of up to 0.6 MPa and a maximum water heating temperature of 90 °C.

These boilers ensure complete fuel combustion and minimize harmful emissions; they are compact, with an optimal balance of size, weight, and thermal output; convenient maintenance and easy cleaning of the heating surfaces are significant advantages of RETRA equipment.

The Retra-4M boilers can operate in automatic fuel loading mode. Fuel is automatically fed from the hopper via screw conveyors (driven by gearmotors) to two pellet burners with a total capacity of 3.0 MW, mounted in the boiler. Maximum efficient combustion in the pellet burners is ensured by air circulation provided by fans. Operation of the screw conveyors and fans is controlled by a microprocessor-based thermostat.

The outer walls of the boiler are insulated with 100 mm thick thermal insulation material.

The tube filling and all walls of the boiler, including the combustion chamber and convection chamber, are water-cooled - water circulates through them.

In addition to water cooling, the combustion chamber is also lined with refractory heat-resistant material.

Advantages:

• automatic operation;
• the possibility of using different types of fuel that are more accessible to the consumer;
• a unique self-cleaning scoop-type burner with water cooling, operating in automatic mode for burning low-quality pellets, coal, husks, wood chips, sawdust and other small-fraction fuel;
• Triple prevention of fire in the auger;
• environmental friendliness - compliance with all sanitary and environmental emission standards;
• convenience, ease of maintenance and long service life of the equipment (10 years or more);
• The uniqueness of the device is also due to its modern automation with a convenient multifunctional menu;
• boilers are made of boiler steel with a thickness of 8 mm;
• the presence of a smokeless combustion system when using any type of solid fuel and combustible waste.

The design of the Retra-4M boiler with a capacity of 3000 kW

1. firebox;
2. convective part of the boiler
3. technological compartment;
4. connecting pipes of the technological compartment;
5. technological compartment door;
6. boiler water jacket;
7. grate pipe;
8. upper combustion chamber;
9. lower combustion chamber;
10. cast iron grate (for manual mode)
11. top hatch;
12. hatch studs;
13. inclined pipes;
14. upper front hatch;
15. lower front hatch;
16. side hatch;
17. ash chute;
18. straight partition;
19. upper hatch;
20. lower side hatch;
21. feed pipe;
22. turnover pipe;
23. water drain pipe;
24. condensate pipe;
25. pipe for safety valve;
26. pipe for pressure gauge;
27. secondary air fan

Types of boilers:

• F – with lined hatches;
• B – with water-cooled hatches;
• P – the front side of the boiler is vertical (straight);
• K – the front side of the boiler is inclined (at an angle).

Upon special request, the boiler heat exchanger can be made reinforced - operating pressure up to 0.6 MPa.

The boiler's undeniable advantage is its unique self-cleaning scoop-type burner , which operates as a single unit, consisting of the boiler and feed hopper connected by a screw conveyor. The unit features a water-cooled housing and a movable platform that moves along guides using an eccentric and geared motor, ensuring even fuel distribution across the entire burner surface and complete combustion. The burner housing also contains nozzles for air supply from the fan. The system has a long service life, is installed on boilers with capacities ranging from 200 kW to 3.0 MW, and can be used with a wide range of fine-grained fuels, as it is unpretentious regarding their quality, grade, and moisture content.

Self-cleaning Burner

1 - fixed tray; 2 - side left part of the housing; 3 - side right part of the housing; 4 - primary air nozzles; 5 - movable tray; 6 - heat-resistant sleeve 7 - guide rod; 8 - feed pipe; 9 - return pipe; 10 - secondary air nozzles; 11 - air chamber; 12 - fan connection pipe; 13 - fan; 14 - eccentric; 15 - eccentric carriage; 16 - gear motor; 17 - auger pipe; 18 - tertiary air nozzle; 19 - air box under nozzles; 20 - tertiary air supply control damper.

Feed hopper

1 - body; 2 - discharge hopper; 3 - airlock dispenser (additional option); 4 - screw conveyor; 5 - conveyor receiving hopper; 6 - conveyor drive; 7 - support post; 8 - adjustment bar; 9 - loading hatch; 10 - axial fuel breaker with drive.

Ash removal system

The ash removal system consists of a set of units whose task is to receive ash at its accumulation points, as well as to transport it to pits or an ash collector (bunker).

1-auger screw; 2-auger body (chute); 3-motor-reducer; 4-intermediate support; 5-end support; 6-gate.

The ash removal system consists of a steel auger, a gear motor, an ash hopper (optional) and automation that controls the operation of the system.

Ash removal is carried out from the convection and combustion chambers of the boiler.

The ash bin is mounted to the flange of the auger system with mounting bolts, allowing for convenient dismantling and removal of ash (ash) that accumulates during operation.

Control system for solid fuel boiler "Retra-4M"

The boiler design provides for its operation together with an electronic control panel, a blower fan, an auger drive and a burner nozzle.

The entire heat-generating equipment system is controlled by a Control Panel, which includes power automation and a controller.

The boiler unit controller monitors the combustion process in the boiler's combustion chamber and the circulation of coolant throughout the heating system. It controls the water circulation pump in the heating circuits, the water recirculation pump for rapid boiler warm-up, the combustion air supply fans (primary and secondary air intake ducts), the fuel auger loaders, and the smoke exhauster. The controller features a "dry contact" for connecting an external alarm to alert the operator in the event of an abnormal system condition. The control principle is to maintain the coolant temperature at the boiler outlet set by the operator by varying the air volume forced into the combustion zone by the fans. If the boiler outlet temperature reaches or exceeds the set value, the controller switches the boiler to "purge mode."

The controller also implements the following functions: monitoring of fuel ignition and burnout in the boiler; protection against coolant freezing - when the coolant temperature is below 5°C, the circulation pump is activated to bleed the system; monitoring of emergency situations, including control of the coolant pressure in the system; self-diagnostics of temperature sensors .

The principle of operation of automation

During and after the automatic system loads the required amount of fuel into the burner, the fan intensively forces air for a set period of time to achieve a stable combustion temperature. This cycle repeats until the water temperature in the boiler rises to the baseline values set by the thermostat. After this, the automatic system switches to combustion mode. When the temperature drops to the set minimum level (recommended: 45-55°C), fuel is automatically loaded from the hopper again, the fan is turned on, and the boiler cycle repeats.

If the temperature reaches the set maximum level (recommended: 85-90 °C), the automation turns off the fuel supply and the fan and goes into support mode.

Delivery set of the boiler "Retra-4M"

Item No.	Name	Quantity in one set, pcs.
1	Boiler "Retra 3000-4M"	1
2	Control panel with controller	1
3	Blower fan for boiler	4
4	Safety valve (verified )	2
5	Service platform with fencing and stairs	1
6	Shut-off and control valves within the boiler	1
7	Grate (cast iron for manual mode )	1 set
8	Self-cleaning burner with water cooling NPS-1500	2
	Blower fan with damper	2
	Geared motor	1
	Burner water cooling system with pump	1 set
	Eccentric key	1
	Eccentric assembly	1
9	8.0 cubic meter feed bin with auger feed	1
	Screw conveyor (auger)	4
	Auger motor-reducer	4
	Fire extinguishing tank with temperature sensor BVTS	4
	Water tank bracket	4
	Axial fuel injection system	2
	Hopper capacity 8.0 cubic meters with stand	1
10	Operating documentation	1 set
11	Set of fasteners	1 set
12	Ash removal system for the Retra 3000-4M boiler with a 0.5 cubic meter bin (additional option)	1

Technical characteristics of boilers of the "Retra-4M" model series with a capacity of 3000 kW

Overall and connection dimensions of boilers of the "Retra-4M" model series with a capacity of 3000 kW