Dosing device
The aim of the invention is to provide a dosing device for improved measuring accuracy during the continuous gravimetric dosing of bulk material, in particular combustibles in pulverulent form. To achieve this, two dosing rotors ( 3, 33 ) are arranged on the same axis, one above the other, with intermediate or discharge openings ( 7, 37 ) being arranged in an offset manner.
1. A dosing apparatus for continuous, gravimetric dosing of bulk material, with a stream of material being conveyed with a first dosing rotor driven about a swiveling axis under determination of a momentary load over a measuring section from a charge opening to an offset intermediate opening, and with a load-sensing apparatus which detects the momentary load of the stream of material guided over the measuring section, and at least a second dosing rotor arranged on the swiveling axis with a discharge opening which is offset to the intermediate opening and wherein the intermediate opening is formed in a housing common to the first and at least second rotor and arranged therebetween and wherein the first dosing rotor revolves on an intermediate wall of the housing, wherein the intermediate wall comprises the intermediate opening, the dosing apparatus comprising one or more pivot bearings engaged with the housing such that the housing can swivel under load of the bulk material.
2. A dosing apparatus as claimed in claim 1 , wherein the dosing rotors comprise substantially radially extending driving webs.
3. A dosing apparatus as claimed in claim 2 , characterized in that the driving webs are connected at their radially outside ends with an outer ring.
4. A dosing apparatus as claimed in claim 3 , characterized in that the outer ring of the dosing rotors has a slightly smaller diameter than a diameter of the housing thereby forming a circumferential gap.
5. A dosing apparatus as claimed in claim 1 , characterized in that the first dosing rotor has a lower height than the second dosing rotor.
6. A dosing apparatus as claimed in claim 1 , characterized in that the second dosing rotor is driven at a higher rotational speed than the first dosing rotor.
7. A dosing apparatus as claimed in claim 1 , characterized in that the intermediate opening and the discharge opening are mutually offset by 180°.
8. A dosing apparatus as claimed in claim 1 , characterized in that the charge opening and the discharge opening are mutually offset by 360° or more.
9. The dosing apparatus of claim 1 , wherein the first dosing rotor is arranged above the second dosing rotor.
10. The dosing apparatus of claim 5 , wherein the second dosing rotor defines a greater volume than the first dosing rotor such that the bulk material experiences a controlled pressure decrease passing from the first dosing rotor to the second dosing rotor.