Open-type radial (circular) storages for process chips
18 October 2022
The increasing demand for timber from many industries, while maintaining an ecological balance, has intensified the growth of timber production without increasing logging volumes. In this context, the sustainable use of wood waste is of particular importance. Wood chips are one of the most frequently used materials in modern pulp and paper production due to their high initial characteristics in terms of homogeneity of size and properties.
The wide range of industrial applications of wood chips, combined with the need for their homogenization and uninterrupted supply to the mill conveyor belt for further technological processing, are the factors that make the construction of specialized blending beds necessary. These warehouses are equipped with modern technology for transporting, homogenising and storing wood chips.
Pulp and paper mills are the largest consumers of process chips. They store and process huge volumes of this material. The value of wood raw material stored in pulp and paper mill warehouses can amount to hundreds of millions of rubles, so companies have specific regulatory requirements for storing wood chips, designed to minimize their losses.
As a rule, technological chips are stored in open warehouses in stacks of triangular or trapezoidal cross-section. The shape of the stack can be rectangular, circular or circular, depending on cost effectiveness, available storage space, and fire safety requirements.
An open radial (circular) stack is the most economically feasible way of storing and averaging process chips when space is tight. In this type of storehouse the chips are stacked in a circular stack. In contrast to conventional longitudinal storage, simultaneous storage and retrieval in the same stack is possible. This method of storing shredded timber ensures low operating and maintenance costs, which makes this format the most attractive.
These storage facilities can hold up to 150,000 m³ of stored material. The circular stack is up to 30 metres high with an outside diameter of up to 210 metres. In addition to increasing the storage capacity, the high stack height also lowers the energy requirements for drying the wood chips after precipitation. This is due to the smaller area over which moisture penetrates the material.
In some cases, a fine-mesh fence, up to 2.5 m high, is placed around the perimeter of the wood chip storage area to prevent wind blowing the wood chips out of the building. This considerably reduces the storage volume to a few thousand cubic metres and reduces the stack height to a maximum of 10 metres.
For safety reasons, the material storage areas must be as hard and level as possible. It is usually asphalt, or gravel with a slight slope for drainage.
Pulp and paper mills store sufficient quantities of wood chips to maintain an uninterrupted production process. However, since storage costs and storage equipment are high, it is not profitable for the mills to keep excessive stocks of raw materials.
- Type of source material (spruce, pine, etc.);
- Density of dry wood;
- The density of the wet wood;
- Moisture content;
- Chip mass fill factor;
- Type of chips (residual chips or from whole logs);
- Average particle size fraction.
The chips are conveyed and homogenized in a radial storage system using a variety of continuous conveying systems. Correct choice of equipment for handling and transportation of raw material depends on many factors: type of material, required storage volumes, size of the chip fraction, need for homogenization, and some others.
Simultaneous stacking, unstacking and averaging of chip stacks in a radial (circular) storehouse can be performed by means of a rotary reclaimer stacker rotating around a rotating support column.
This type of equipment combines the functions of a stacker and a fence at the same time. The material is stacked in a circular stack using a circular stacker and the reclaimer, which is mounted on a slewable support column in common with the stacker, performs the disassembly and homogenisation. The slewing support device allows the reclaimer stacker to rotate through a radius of 360°. The material from the stack is transported to the transfer hopper. The material is discharged by free flowing through the unloading unit. Under stack conveyors are installed in the underground gallery. The unloading speed is controlled automatically to suit the capacity requirements of the customer's process plant. The discharge volume is continuously monitored by the belt conveyor dosing weigher.
The rotary stacker-reclaimer is an integrated system designed for stacking and processing large quantities of technical chips.
- Smooth automatic start-up;
- Protection of motors and mechanisms against overloads and operating errors;
- Diagnostics of the actuator status;
- Automatic generation of information messages on inadmissible operating conditions of the stacker-reclaimer;
- Emergency stop of conveyor system and activation of fire-fighting systems, emergency announcement system;
- Remote control.
- Minimisation of the amount of manpower required to maintain a radial woodchip stack;
- Virtually eliminates the need for expensive manual labour;
- The possibility of using a full 360° rotation radius for stacking and averaging woodchips;
- Use of an active harrow to thoroughly mix the material before it is fed evenly onto the mill's conveyor belt.
The use of high-capacity circular sawmills makes it possible to process large quantities of chips as efficiently and economically as possible in a continuous operation with limited space.
Only foreign equipment is currently used in circular stockyards. In today's environment this exposes the industry to serious risks of component and service shortages. The need for such equipment made in Russia exists and will only increase. Timber industry holdings are already laying down the requirement to use Russian equipment when planning new facilities. Technoros is the only company that offers equipment for mechanization of wood chips storage.
Please contact us for more information: +7 (812) 718-82-82.
Our specialists will answer all your questions and provide detailed information about our equipment.
You can also write to us at: info@tehnoros.ru
Announcement photo: oblgazeta.ru
The wide range of industrial applications of wood chips, combined with the need for their homogenization and uninterrupted supply to the mill conveyor belt for further technological processing, are the factors that make the construction of specialized blending beds necessary. These warehouses are equipped with modern technology for transporting, homogenising and storing wood chips.
Photo from website: constantcontact.com
Pulp and paper mills are the largest consumers of process chips. They store and process huge volumes of this material. The value of wood raw material stored in pulp and paper mill warehouses can amount to hundreds of millions of rubles, so companies have specific regulatory requirements for storing wood chips, designed to minimize their losses.
As a rule, technological chips are stored in open warehouses in stacks of triangular or trapezoidal cross-section. The shape of the stack can be rectangular, circular or circular, depending on cost effectiveness, available storage space, and fire safety requirements.
An open radial (circular) stack is the most economically feasible way of storing and averaging process chips when space is tight. In this type of storehouse the chips are stacked in a circular stack. In contrast to conventional longitudinal storage, simultaneous storage and retrieval in the same stack is possible. This method of storing shredded timber ensures low operating and maintenance costs, which makes this format the most attractive.
Photo from website: lesprominform.ru
These storage facilities can hold up to 150,000 m³ of stored material. The circular stack is up to 30 metres high with an outside diameter of up to 210 metres. In addition to increasing the storage capacity, the high stack height also lowers the energy requirements for drying the wood chips after precipitation. This is due to the smaller area over which moisture penetrates the material.
In some cases, a fine-mesh fence, up to 2.5 m high, is placed around the perimeter of the wood chip storage area to prevent wind blowing the wood chips out of the building. This considerably reduces the storage volume to a few thousand cubic metres and reduces the stack height to a maximum of 10 metres.
For safety reasons, the material storage areas must be as hard and level as possible. It is usually asphalt, or gravel with a slight slope for drainage.
Pulp and paper mills store sufficient quantities of wood chips to maintain an uninterrupted production process. However, since storage costs and storage equipment are high, it is not profitable for the mills to keep excessive stocks of raw materials.
When planning the type and size of each chip stack, many factors directly related to the material must be considered:
- Type of source material (spruce, pine, etc.);
- Density of dry wood;
- The density of the wet wood;
- Moisture content;
- Chip mass fill factor;
- Type of chips (residual chips or from whole logs);
- Average particle size fraction.
The chips are conveyed and homogenized in a radial storage system using a variety of continuous conveying systems. Correct choice of equipment for handling and transportation of raw material depends on many factors: type of material, required storage volumes, size of the chip fraction, need for homogenization, and some others.
Simultaneous stacking, unstacking and averaging of chip stacks in a radial (circular) storehouse can be performed by means of a rotary reclaimer stacker rotating around a rotating support column.
Photo from website: andritz.com
This type of equipment combines the functions of a stacker and a fence at the same time. The material is stacked in a circular stack using a circular stacker and the reclaimer, which is mounted on a slewable support column in common with the stacker, performs the disassembly and homogenisation. The slewing support device allows the reclaimer stacker to rotate through a radius of 360°. The material from the stack is transported to the transfer hopper. The material is discharged by free flowing through the unloading unit. Under stack conveyors are installed in the underground gallery. The unloading speed is controlled automatically to suit the capacity requirements of the customer's process plant. The discharge volume is continuously monitored by the belt conveyor dosing weigher.
The rotary stacker-reclaimer is an integrated system designed for stacking and processing large quantities of technical chips.
The equipment is supplied with a state-of-the-art automated control system that provides:
- Smooth automatic start-up;
- Protection of motors and mechanisms against overloads and operating errors;
- Diagnostics of the actuator status;
- Automatic generation of information messages on inadmissible operating conditions of the stacker-reclaimer;
- Emergency stop of conveyor system and activation of fire-fighting systems, emergency announcement system;
- Remote control.
The main advantages of using a rotary stacker-relaymer are:
- Minimisation of the amount of manpower required to maintain a radial woodchip stack;
- Virtually eliminates the need for expensive manual labour;
- The possibility of using a full 360° rotation radius for stacking and averaging woodchips;
- Use of an active harrow to thoroughly mix the material before it is fed evenly onto the mill's conveyor belt.
The use of high-capacity circular sawmills makes it possible to process large quantities of chips as efficiently and economically as possible in a continuous operation with limited space.
Only foreign equipment is currently used in circular stockyards. In today's environment this exposes the industry to serious risks of component and service shortages. The need for such equipment made in Russia exists and will only increase. Timber industry holdings are already laying down the requirement to use Russian equipment when planning new facilities. Technoros is the only company that offers equipment for mechanization of wood chips storage.
Please contact us for more information: +7 (812) 718-82-82.
Our specialists will answer all your questions and provide detailed information about our equipment.
You can also write to us at: info@tehnoros.ru
Announcement photo: oblgazeta.ru