COAL PRODUCTION USING MODECO SERIES CHARCOAL BURNING KILNS
There is a variety of methods and techniques of charcoal burning, as well as various raw wood pyrolysis units in the world. Each technology has its own features, advantages and disadvantages.
The technology for ModEco charcoal burning kilns has been developed on the basis of scientific approaches to the raw wood pyrolysis to eliminate adverse features of existing charcoal burning units. The wishes of experienced charcoal burners “born” in the course of continuous practical activities for charcoal production were also taken into account.
What has been implemented in ModEco charcoal burning kilns? What is the pyrolysis method used in our kilns?
A charcoal burning kiln is environmentally friendly. This means that absolutely all products resulted from thermal decomposition of wood are burnt in a hearth and generate the required volume of the heat transfer medium to perform pyrolysis. ModEco charcoal burning kilns do not generate resin, tar or pyroligneous distillate (this name was given to liquid pyrolysis products by charcoal burners). While burning wood decomposition products in the hearth, the feedstock with a relative moisture content of up to 55 % is charred, without additional burning of firewood in the hearth.
To charge the hearth with feedstock, a conveying type transporter is used. This feedstock charge method is more appropriate as compared to crane mechanisms.
Stationary retorts are used in ModEco charcoal burning kilns. Retorts are always hot, whereby systematic heating and cooling of retort metal is eliminated (which has an adverse effect on metal).
ModEco charcoal burning kilns provide for pre-drying of the feedstock by the “through layer” method. This means that each individual wood piece is purged with the heat transfer medium. The feedstock volume required for one retort is charged into two drying baskets and installed on the same drier. The availability of two baskets ensures two-stage feedstock drying. This method for feedstock drying is most effective. It guarantees smooth drying and large-sized coal reception provided that large-sized feedstock is used.
All retorts in ModEco charcoal burning kilns are at the same distance from the hearth and this guarantees absolutely equal temperature conditions and temperature modes for each individual retort. As a result, each retort produces coal, which characteristics do not differ from the characteristics of coal produced in other retorts. The kiln can be operated at full load (all four retorts are in operation) and with less quantity of operating retorts.
The coal in ModEco kilns is discharged to quenchers in hot condition. The coal discharge to quenchers for cooling is more economically feasible as compared to coal cooling in retractable retorts. The cooled coal is discharged to special stabilizers (metal boxes with multiple holes). While staying in stabilizers, the “hungry” coal absorbs oxygen. This is an integral part of the charcoal burning process, which must not be violated in any case.
All ModEco charcoal burning kilns are completed with an automated control system (ACS). The ACS minimizes the human factor impact on the kiln operation by means of automatic monitoring of all the temperature modes both in the hearth and in each individual retort and controls them automatically. The use of high quality thermocouples, servomotors, and a controller makes the ACS reliable in operation and most necessary function, which guarantees stable operation of the kiln for many years. All the operating parameters of the kiln and retort modes are monitored visually, on the master computer monitor. Temperature charts and operating modes of each individual retort are memorized on the server.