Котел Retra-4М Plus 600 кВт

Fuel can be loaded and burned in three ways

Manual loading mode

Fuel is loaded through the top hatch onto the grate (upper combustion chamber), where it is burned. This mode is designed for use with any large-sized fuel (wood, briquettes, lump coal, straw, etc.). Primary air is supplied through a splitter by a fan installed at the bottom of the rear wall of the boiler. secondary air for burning pyrolysis gases is supplied through nozzles on the side and top walls of the furnace by a fan located on the top wall. The combustion process and the operation of the central heating pump are controlled by a control panel, while ash removal is manual.

Torch burner operating mode

A torch burner is installed in the lower hatch of the boiler, into which fuel is mechanically fed from the hopper. Fuel combustion takes place in the lower chamber. This automatic loading mode is designed for burning pellets (including agropellets). The pellet burner flame is directed at the rear wall of the boiler furnace with refractory lining. The process of auto-ignition, combustion, and burner cleaning is controlled by a multifunctional control unit. Mechanized fuel supply, hopper, and automation are supplied complete with the torch burner.

Retort burner operating mode

The side hatch of the boiler is dismantled and replaced with a retort burner. Fuel is fed from the hopper by means of a burner screw, and fuel combustion takes place in the lower chamber. This automatic loading mode is designed for burning pellets and fine coal. The combustion process is controlled by a control unit. The fuel feed hopper is protected by a fire extinguishing system with a BVTS thermostatic valve.
The boilers are designed to operate in central water heating systems with forced (closed pressurized heating system) or natural (open heating system) circulation of the heat carrier for hot and cold water supply to residential buildings, cottages, industrial and warehouse premises, commercial facilities, social and administrative buildings.
The boilers are designed to operate in systems with a working pressure of no more than 0.2 MPa (0.6 MPa on request) and a water temperature at the boiler outlet of no more than +95 °C.

Boiler advantages

• Three operating modes.
• Brand reliability.
• Two combustion chambers.
• Modern automation.
• 5-year warranty.
• Ongoing service.
• The boiler design allows for burning different types of fuel (pellets, coal, wood, briquettes, sawdust, wood waste).
• High versatility: possibility of using different types of burners or manual mode.
• The heat exchanger wall thickness is 5 mm (up to 100 kW) and 6 mm (150 kW), which ensures a long service life.

Structure of the Retra-4M boiler with a capacity of 25-1250 kW

The steel heat exchanger (1) consists of three main parts: at the bottom there is a lower combustion chamber (15) for use with the burner, at the top there is an upper combustion chamber (16) for manual mode; behind them there are straight partitions (21) that form the convective channels of the heat exchanger. Both chambers are separated by a grate (9). The straight partitions and walls of the heat exchanger are cooled by water, forming a so-called “water jacket.”

When the boiler is used in manual mode, the combustion process takes place in the upper combustion chamber on the grate bars. A primary air splitter (5) is located under the grate bar, which together with the fan (8) forms the primary air supply system. Secondary air enters the combustion chamber from the fan (7) through supply manifolds and nozzles (10). The lower combustion chamber also functions as an ash accumulation chamber with an ash box (6) installed.

The boiler comes with a control panel with temperature sensors that are immersed in the sleeve (11). The boiler is connected to the water supply system via a supply pipe (12) located on the upper wall of the boiler and a return pipe (13) located on the rear wall of the boiler. Also on the rear wall of the boiler there is a drain pipe with a ball valve and a safety valve that activates when the pressure exceeds the permissible value. A pressure gauge with a valve (14) is located on the upper wall of the boiler.

When using the torch (17) or retort (19) burner mode, the primary air splitter (5) is removed and a primary air manifold plug (18) is installed. The rear wall of the lower combustion chamber (15) is protected from the burner flame by a lining (21).

Boiler types
F – with lined hatches;
B – with water-cooled hatches;
P – vertical (straight) front side of the boiler;
K – inclined (angled) front side of the boiler.
Upon special order, the boiler heat exchanger is manufactured in a reinforced version with a working pressure of up to 0.6 MPa.

Boiler operating principle

Water from the heating system enters the boiler through the return pipe (13), spreads throughout the internal cavities of the heat exchanger and extracts heat from the burning fuel through its metal walls (by contact and radiation in the furnace) and gaseous combustion products (by convection in other parts of the heat exchanger). The heated water enters the heating system through the supply pipe (12).

In boiler operating modes with a torch or retort burner, the primary air diffuser and cast iron grate are removed, and the primary and secondary air fans of the boiler are not used (only the fan installed on the burner is in operation); a plug is installed in place of the primary air diffuser. Ash removal from the boiler is manual using an ash pan. For automatic operating modes, the boiler is equipped with a hopper (for a torch burner, a hopper adapter and a flexible screw conveyor are additionally supplied). After the boiler is ignited, the combustion process is controlled automatically. All you have to do is refill the hopper with fuel.

Scope of delivery

1. Retra-4M Plus boiler
2. Fan with damper, 2 pcs.
3. Control panel
4. DM 05-MP-ZU pressure gauge
5. Crane under the pressure gauge
6. Safety valve
7. Ball valve 1/2" 2 pcs.
8. Plug for Pancerpol PPSM TRIO burner
9. Fasteners
10. Operating documentation
11. Cast iron grates (on request)