Method and apparatus for external heating of rotary kilns for the pyrolysis of coal and other bituminous materials
Patent Information
- Application Number
- DEH0082438
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 1920-09-12
- Publication Date
- 1924-02-22
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Rotary kilns for carbonizing coal and bituminous materials face challenges in achieving uniform temperature distribution along the kiln length, preventing local overheating, and ensuring efficient heat transfer while maintaining high-purity combustion.
A spatially separated furnace with a muffle-shaped design is used to generate combustion gases at high temperature, which are cooled and directed through ducts around the rotary kiln, ensuring uniform heat distribution and temperature control, using fresh air to regulate the gas mixture temperature.
Achieves uniform temperature distribution and efficient heat transfer in rotary kilns, preventing overheating and optimizing fuel usage while maintaining high-purity combustion.
Description
[0001] Method and apparatus for external heating of rotary kilns for the carbonization of coal and other bituminous materials. Rotary kilns for The smoldering of coal and other bituminous materials at low temperatures requires very special heating arrangements, including the following: Conditions must be observed. First, the temperature of the rotary kiln wall should be as uniform as possible along its entire length. The latter, approximately q.50 to 500°C; it should not rise significantly above this at any point, and in particular, it must be avoided. This will cause local overheating of the furnace walls to red heat. It is also advisable to prevent the smoldering material, which is caused by the rotation, from becoming hot. Since the oven is in a slanted position, the heat emanating from the firebox should be directed as directly as possible. The heating must also, of course, be... itself must be as perfect as possible, i.e., the gas or other fuel used to heat the rotary furnace must be as perfect as possible. burn.
[0002] These partly contradictory requirements are met by a method for heating rotary kilns and an arrangement of the Heating system, as shown schematically in the drawing in Fig. z in a vertical section and in Fig. 2 in a horizontal section. The embodiment shown is, in accordance with the invention, as follows.
[0003] The actual firing unit a is arranged in a manner known per se, spatially separated from the rotary furnace b, and has a muffle-shaped Training. In the furnace, bituminous coal, semi-coke, lignite, etc., are processed in lump or dust form, or as gas, or also in solid and gaseous form. Fuel mixtures or liquid fuels are burned almost completely at high temperatures. Any residues in the Unburned fuel particles still contained in the combustion gases ignite behind the combustion chamber on the glowing objects that enter their path. vaulted walls. The combustion chamber a is supplied by a feed channel c for the heating gases, which is oriented appropriately perpendicular to the longitudinal axis of the rotary kiln. which is routed below the rotary kiln and terminates in two lateral branch channels 1a and i, with the heating channel k surrounding the rotary kiln connected. The supply channel c is connected at its junction with the heating channel k by a brick tongue extending almost to the wall of the rotary kiln. f is blocked off by the fox g flying behind the tongue, into which the hay channel k merges. Behind the furnace, the supply channel c descends in order to The heated ceiling tongue c causes combustion of the impacting fuel particles carried along by the combustion gases. to effect this. In front of the tongue e, the walls of the supply branch channels h and i are provided with fresh air inlet openings d, which are designed in a known manner. Their opening cross-section can be varied. The combustion gases entering the supply channel c at approximately 120°C. are cooled down so much by the cold or only moderately warm fresh air entering through the openings d that the mixture of combustion gases and air between the tongues e and f at a temperature of about 750° C surrounds the rotary furnace b and the iron wall cles the latter a It has an average temperature of approximately 4500°C. This is advantageous in order to achieve the most complete possible utilization of the fuel and low emissions. To achieve the required exhaust gas temperature, the combustion gases mixed with air are sent through an air preheater before entering the fox. step.
Claims
[0004] PATENT APPLICATION: i. Method for external heating of rotary kilns for the carbonization of coal and other bituminous materials, thereby characterized in that the combustion gases used for heating in the supply channel to the heating channel (k) of the rotary furnace pass through openings (d) with Air is mixed to cool the mixed gases to the temperature required for heating the rotary furnace.
2. Device for operating of the method according to claim z, characterized in that the supply channel (c) for the heating gases is perpendicular to the longitudinal axis of the rotary furnace is brought in below these and terminates in two lateral branch channels (h, i) that extend over the length of the furnace and are located between tongues (e, f) in the heating channel (k) above, surrounding the furnace, which begins at the surface of the rotary furnace, on which, under the influence of The rotation of the oven causes the smoldering material to accumulate inside the oven and transition into the flue (g) behind the bridge (f).
3. Device according to claim 2, characterized in that the openings (d) in the walls of the branch channels (h, i) are located behind the firebox (a) and in front of the tongues (e and f).