A special development for the burning of low-calorific gases
The LOMA-heater combined with a multiple lance burner represent a special development and is characterized by the following features:
minimum stored heat,
low preheating period only when starting from the cold state,
wide control range,
plant can be immediately started and shut down,
no supporting burner necessary,
no emergency chimney necessary.
The multiple lance burner (1) is made up of a number of individual nozzles, for both low-calorific gas and combustion air. Both constituents meet within the nozzle mixture; the basic requirement for efficient combustion is therefore achieved.
Owing to this flow design, it is possible to carry out the major portion of the combustion process in a very small burner muffle (3).
To start the hot gas generator, is it essential to use a start burner (2) installed co-axially.
This start burner has the function of heating up the interior wall of the burner muffle to a surface temperature of approx. 700 °C - the inflammability limit temperature of CO. After the main burner has been started, the start burner is switched off.
At the same time, the start burner can be sized so that an entire plant can be heated up. e.g. for the dry-grinding of coal, dry-grinding of slag etc.
To ensure a stepless operation, the capacity ranges of the main burner and the start burner are designed to overlap.
The main burner has a control range of 1:10, the start burner control range is 1:5 - 1:8. Every essential operating point within the control range of approx. 1:50 - 1:70 can therefore easily be achieved.
The hot flue gases escaping from the burner muffle (3), are in the area of the perforated jacket (4), mixed with the process air to be heated up, which is supplied to the hot gas generator via the spiral housing (5).
LOMA-heater Type LF 20 with a multiple lance burner for combustion of blast furnace gas at steel plant Dillingen, Germany with a heat capacity of 15 x 106 kJ/h
Its main application is the burning of blast furnace gas. By means of this combustion system, low-calorific gases with a thermal value from 2,500 kJ/m3 (S.T.P.) are burned without a supporting burner.
Such hot gas generators are used in connection with Loesche roller grinding mills in dry-grinding plants to process coal for the smelting of iron ore.
Since 1991 fourteen hot gas generators - as described - have been built and put into operation. The thermal output of these plants is between 16.7 x 106 kJ/h and 54 x 106 kJ/h.