[0001] The subject of the invention is a cover of the combustion chamber in a pellet burner
which can be applied both in households and other communal facilities objects, and
store or production rooms.
[0002] Pellets and agropellets are much appreciated for their high comfort of use and therefore
they are successfully used as an effective fuel for individual boilers of central
heating systems, stoves, fireplaces and other heating devices designed for heating
buildings and rooms, and equipped with a pellet container, a dosing device, and a
feeder (conveyor), The burners designed for burning pellets, made of heat-resistant,
acid-resistant, and stainless materials, are mounted in the doors of heating boilers
of any type, i.e. the oil, gas or solid fuel ones.
[0003] There is known an aeration mechanism of the combustion chamber given in the Polish
application description
P.409186 (A1) and shown in a pellet burner presented in the drawing
Pos. 1a and
Pos. 1b, in addition, it relates to the burner comprising a steel body (1) which is a fixed
housing with an inlet hole (2) for pellets and rotary combustion chamber (3) surrounded
with a cylindrical, fixed cover, permanently connected with the body (1). In addition,
a space between the combustion chamber (3) and the cover (4) is a ring-shaped duct
(5) supplying air to the combustion chamber (3) throughout holes and/ or inflating
nozzles (6) placed on its circumference. In this solution the rotary combustion chamber
has several longitudinal diaphragms (7) having a form of shutters, swingably mounted
on the outer surface of the combustion chamber and obscuring the inlet holes (6) of
air, operating together with a fixed control ring (9) situated perpendicularly to
the longitudinal axis of the chamber around its rear part, in addition, an inner surface
of the control ring (9) functions as a cam pressing the diaphragms to the combustion
chamber surface or releasing them in accordance with a sequence of the preset phases.
[0004] The combustion chamber has a form of a prism or a truncated pyramid, the base of
which is a regular polygon.
[0005] The diaphragms are arranged in twos on either side wall of the combustion chamber.
[0006] The inner surface (10) of the control ring (9) has a shape of arcs of two radius
connected with each other by short, straight segments.
[0007] The ring-shaped duct (5) supplying air to the combustion chamber (3) is closed in
front of the cover (4) by its flange ring and a sealing ring operating together with
it, which is permanently connected with the outer surface of the combustion chamber
(3).
[0008] A certain disadvantage of this solution consist in the fact that when the material
is heated up to a very high temperature of 700 - 800° C the evident thermal expansion
of the combustion chamber inside the burner occurs, which may result in some friction
and seizure events, followed by a possible overloading and stopping a motor.
[0009] The subject of the invention is a cover of the combustion chamber in a pellet burner,
having a housing with an inlet hole for pellets and a rotary combustion chamber surrounded
by a cylindrical cover connected with the housing, in addition, a space between the
combustion chamber and the cover is a ring-shaped duct supplying air to the combustion
chamber throughout inlet holes and/or nozzles located on its circumference, the ring-shaped
duct supplying air to the combustion chamber is closed in front of the cover by its
flange ring, directed towards the inside, and a sealing ring operating together with
it, permanently connected with the outer surface of the combustion chamber. According
to the model, a rear part of the cover is permanently connected with a compensatory
plate, a surface of which is perpendicular to the longitudinal axis of the cover,
in addition, the compensatory plate is elastically connected with a seat of the burner
housing. It is advantageous that the compensatory plate has mandrels, which are slidably
mounted in holes of the burner housing seat and they are ended with heads. There are
compensatory springs placed on these mandrels.
[0010] Thanks to the solution according to the invention, a simple solution improving the
work of the pellet burner has been developed, especially useful in case of burners
equipped with a rotary combustion chamber - preventing formation of thermal stresses,
seizures, and friction during the burner's operation.
[0011] The subject of the invention presented in an exemplary embodiment is shown in a schematic
drawing, Fig. 1 of which is a side view of the pellet burner; Fig. 2 shows a side
view of the combustion chamber cover; Fig. 3 shows a longitudinal section of the combustion
chamber cover; Fig. 5 shows a front part with a partial perspective view of the pellet
burner; Fig. 6 shows a detail of the elastically mounted cover in the burner's off-position;
Fig. 7 shows a detail of the elastically mounted cover in the burner's on-position.
[0012] A cover of the combustion chamber in a pellet burner, according to the invention,
is designed for a burner comprising a housing
1 with an inlet hole for pellets
2 and a rotary combustion chamber
3 surrounded by a cylindrical cover
4 connected to the housing
1, in addition, a space between the combustion chamber
3 and the cover
4 is a ring-shaped duct
5 supplying air to the inside of the combustion chamber
3 throughout inlet holes and/or nozzles placed on its circumference (not shown in the
drawing).
[0013] The ring-shaped duct
5 supplying air to the combustion chamber
3 is closed in front of the cover
4 with its flange ring
6 directed towards inside of the chamber and operating together with a sealing ring
7 permanently connected with the outer surface of the combustion chamber
3. A rear part of the cover
4 is permanently connected with the compensatory plate
9 the surface of which is perpendicular to the longitudinal axis of the cover, whereas
the compensatory plate
9 is elastically connected with the housing seat
10 of the burner housing
1. For ensuring an elastic connection the compensatory plate
9 is provided with mandrels
11 slidably mounted in holes
12 of the seat
10 of the burner housing
1 and ended with heads
13. There are compensatory springs
14 placed (supported) on these mandrels
11.
[0014] As a result of such mounting, the cover
4 can move along the axis in a reciprocating motion. When the temperature reaches the
value of 700° C during the pellet burner's operation, the combustion chamber
3 is sub-ject to the action of deforming forces which cause the thermal expansion of
the chamber. The combustion chamber
3 expands and the sealing ring
7 placed on its circumference presses on the ring-shaped flange
6 of the cover
4 making it move forwards. The thermal contraction of the combustion chamber
3 during the cooling-down process makes the sealing ring
7 move backwards which - releasing pressure in the ring-shaped flange
6 - makes the movement of the cover
4 backwards possible due to the action of the compensatory springs
14.
1. A cover of the combustion chamber in a pellet burner, having a housing with an inlet
hole for pellets and a rotary combustion chamber surrounded with a cylindrical cover,
connected with the housing, in addition, a space between the combustion chamber and
the cover is a ring-shaped duct supplying air to the combustion chamber throughout
holes and/or nozzles placed on its circumference, and the ring-shaped duct supplying
air to the combustion chamber is closed in front by a flange ring directed inwards
the chamber and a sealing ring operating together with it permanently connected with
the outer surface of the combustion chamber, characterised in that a rear part (8) of the cover (4) is permanently connected with a compensatory plate (9), a surface of which is perpendicular to a longitudinal axis of the cover, whereas
the compensatory plate (9) is elastically connected with the burner housing (1);
2. The cover according to claim 1, characterised in that the compensatory plate (9) has mandrels (11) slidably fitted in the holes (12) of a seat (10) of the burner housing (1) and ended with heads (13) and supporting compensatory springs (14).