KWM-SG Boilers are a new version of the boilers with the regulated process of combustion, feeder with fine coal. In their design we have used many years of experience acquired during the production of the already known KWM-S. The combustion of the fuel is the same as it was in KWM-S, i.e. from top to the bottom.

– A feature and advantage of both of these boilers is: easier handling, especially in terms of clearing,
– Longer service life,
– Smaller footprint of the boiler in the boiler room, with its greater height.
The boiler is supplied in an assembled state with the batch door, ash door and furnace door, with thermal insulation.
– Our boiler is equipped with: Microprocessor controller,
– Fan,
– Operating instructions of the boiler and the controller.

On the housing of the boiler there is placed a visible identification plate that specifies among others, the energy efficiency of the boiler. These elements and the characteristics of the boiler in this manual (Table 1) are the conditions allowing the boiler on the market. Design and construction of KWM-SG are compatible with the PN-EN 303-5 and essential requirements regarding safety, as defined in the relevant regulations (EU Directives). The boiler will be warranted. Detailed warranty conditions are specified in this manual and in the enclosed warranty card. A fan and regulator (sales teams) also have warranty cards. KWM-SG Boilers, installed and operated in accordance with the requirements of this manual, do not require constant maintenance after starting. Carefully reading of the manual instruction of the boiler, that contains information relating to the construction, installation and manner of operation is necessary to ensure the proper and safe use.

Intended use of KWM-SG:
KWM-SG Boilers are designed to heat water to the outlet temperature not exceeding 90 °C. They are mainly used in central heating systems in residential, commercial pavilions, workshops, farms, greenhouses, schools, etc. KWM-SG Boilers can be installed only in the installations of the open system, protected in accordance with PN-91 / B-02413, and can work in a gravity or a pump system.

Selection of boilers for heating systems:
The basis for the selection of the boiler for central heating is a thermal balance of the heated area. The nominal heat output of the boiler should be 15-20% higher than the calculated heat demand of heated rooms. Table no. 1 lists approximate surfaces rooms that can be heated with KWM-SG boilers. These data are indicative and are specified for rooms with a height of 2.5 m and determined on the basis on years of experience, taking into account the state of room warming.

Fuels recommended for use for KWM-SG are shown in Table no. 1. The use of low-grade coal from those listed in the table causes a decrease in thermal efficiency. The fine coal had to be use in a slightly moistened state (the humidity about 20%). The fine coal should have a specific granulation and it should have a crumbly structure, permeable to air. Too small coal will have a bad burn properties or the combustion process will even disappear. In general, fine coal stored outdoors under a roof meets the requirements of moisture. The burning of wet sawdust or wet wood is unacceptable and it causes premature failure of the boiler.

Technical characteristics:
Detailed characteristics of KWM-SG are given in Table No.1

Description of the construction of boilers:
The construction of KWM-SG is shown in Fig. 1.
The boiler body is made of two co-centric cuboids, forming a water space between them, combined with reinforcing struts. The entire structure is made of steel sheet combined with electric weld. The body consists of a furnace and convection. Furnace is cuboid-shaped closed with water grate from the bottom. Below the grid is sealed ash box. The furnace of the front is equipped with a sealed furnace and batch door.

Convection part of the boiler is made of four horizontal channels that allow the flow of exhaust gases from the combustion chamber to the flue pipe and chimney. Commercial horizontal convection channels are suitably inclined, thereby to prevent accumulation of gas. From the top of the last channel there is derived a flue. The design of the boiler allows periodic cleaning of the heat exchange surface through the two holes placed in front of the boiler and the batch, furnace and ash doors. All doors and hatches covers are fitted with gaskets with glass sealant with cross-section 15x15mm and during operation of the boiler they must be tightly closed. Furnace door are protected by heat-resistant mass concrete. In the upper part of the boiler there are arranged nozzles and the supply of copper alloys and the sleeve of the sensor controller. In the lower rear part of boiler there is a connector of return water, and in the front lower portion of the drain outlet. The fan that supplies air to the boiler and the microprocessor controller are located on the upper wall of the boiler. Between the fan and the air chute there is placed special diaphragm, that opens automatically when you start the fan. The air from the fan is supplied to the combustion chamber and under the grate into the Ash box. Air around the combustion chamber is distributed by angle which openings are directed at a right angle relative to the chamber. The amount of air supplied to the boiler varies, closely controlled by the microprocessor controller as a function of water temperature. In general, in the first chase of combustion (5-6 hr.) air supply under the grate may be partially throttled and after that time it can be opened. During operation of the boiler, the secondary air flap which is located on the batch door should be slightly lifted with adjustment screw (approx. 2 mm).

– Microprocessor controller in a very simple way makes it possible to: set the desired temperature on the boiler,
– setting the maximum fan capacity,
– setting the blow parameters i.e. time and frequency

After reaching the required temperature controller turns off the fan. In between the next switching, the controller automatically causes the control blow. These parameters are set at the factory, on the basis of experience and generally they do not require changes.

The controller is equipped with sensors of work control and emergency shutdown of the boiler.
In an emergency, for example after excess over the water temp. 95 ° C, the red light Alarm flashes and it activates sound alarm and circulation pump.

According to customer requirements, the boiler can be equipped with a regulator with timer, enabling automatic programming of temperature changes of the boiler at different times. After the combustion process and when the temperature in the boiler decrease to 35 ° C, the controller will switch off the fan and the circulation pump (if it was switched on). The user must carefully read the operating instructions of the controller.
In boilers, manufacturer has introduced structural modifications, to make their functioning better and better. Supplied boilers may differ in small details from the presented instructions or offer.