One of the main goals and approaches in the world is energy saving and optimal using resources, therefore increase interest in the exploitation of natural bio-resources. Sawdust, the by-product of most woodworking processes, and facilities with fine particles of wood everywhere. Wood waste is often stored in the open air. Wood-processing enterprises gather a huge amount of waste, which raises the question of its rational use and, therefore, leads to additional costs. Our company offers the option to recycle waste. In order to inform you, we will introduce you in recycling wood waste. It will take into consideration briquetting technology and equipment to produce briquettes. Our company is engaged in production of equipment for briquetting of wood waste. We will describe you the technological process of producing briquettes as well as utility of our equipment. Briquetting process consists of several stages: Stage 1 – crushing machine (shredder); Stage 2 – airflow drying (aerodynamic); Stage 3 – mechanical briquetting press An example of a raw: wood waste with natural moisture content. In this example, briquetting process is composed of the above listed stages. The first stage of briquetting process: Shredding. Shredding equipment consists of a disc crusher or a shredder (primary crushing), a chip metering hopper and a hammer crusher. In this example, we will consider a disk crusher. Large wood waste is delivered to the shredder RM 800.4. It is a stationary disk shredder designed for shredding wood waste: laths, slabs, etc. Shredder knives crush wood waste into chips ranging from 8 to 20 mm. From RM 800.4 chips fall into chip collection bin. Bin is designed for uniform feed of wood chips to the shredder RM 800.7. From collection bin wood chips get through a screw conveyor feed into the shredder RM 800.7, where chips are crushed by hammers mills into fraction of 1 to 10 mm. The second stage of briquetting process: Aerodynamic drying of sawdust. Chopped raw material gets from shredder RM 800.7 into a metering hopper of aerodynamic dryer DAD-0.6-1.2. Metering hopper of aerodynamic dryer is a welded construction with an integrated screw conveyor and an agitator and it serves as reservoir for raw material supplied to the dryer. From metering hopper crushed wood chips get through a screw feed into a dryer. Rapid flow of hot air in a dryer keeps raw material in suspension. Air in a dryer is heated by a heat generator operated on solid fuel. Heat generator is a welded construction in the form of furnace with a combustion chamber internally isolated by fire bricks, thermal flash suppressor and air plenum chamber. Since air flow rate is very high and materials are right in the flow, heat exchange between air and material is very high. In the process of drying, pure cold air is heated by heat generator and mixed with wet material whereby wet sawdust is dried in few seconds. Further, dry materials are run through a fan and cyclone, and exhaust air is discharged into atmosphere. The third and final stage of briquetting: Pressing by mechanical press. At this stage prepared material with particle size up to 7 mm and humidity of 12.8% gets in press metering hopper through a dryer steam separator. Metering hopper of briquetting press is a welded construction with an integrated screw conveyor and an agitator and is a reservoir for raw material. Then the raw material is distributed by the sleeve, which is located in the front part of the piston through carrying conveyors with horizontal and vertical movements. Its operating pressure is 1,400 kg/cm. Pressure-lubricating system ensures low wear of parts in the process of workloads. After being pressed, briquettes are pushed through removal mechanism (conveyor) which protects briquettes from premature mechanical action and provides access when necessary. Mechanism design also provides a visual control of briquetting process. Advantages of a mechanical press: a. No carbon monoxide during operation (no need to install exhaust system) b. No heating elements for forced heating of briquetting zone of a press (energy saving) c. ease of use; d. 1500 to 3000 nonstop operating hours without replacement of wearing parts (parts are replaced within 30 minutes) While developing a press our team paid special attention to such important requirements and particularities as: • Ease and reliability of operation and maintenance; • Maximum simple design of press units; • Availability of spare parts and components used in mechanical units of a press.
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