Presently the peat pellets enjoy the growing popularity over the traditional types of peat fuel (such as lump or milled peat fuel) in view of their high technological effectiveness and environmental friendliness.
As a rule the peat pellets used for fuel are produced from milled peat that has undergone a preliminary drying in natural conditions in the fields until its moisture content equals 45-60%. Before being delivered to processing plants the milled peat is refined on bolting machines where big foreign bodies (rocks, roots of trees etc.) are filtered out.
The whole string of the peat pellets’ fuel production can be broken down into the following constituent elements:
I. The preparation area:
In this area the humid raw material is being ground in hammer mills, after which filaments and wood residue that are bigger in size that 10 mm are being separated. Such peat is ready for drying, which is the next processing stage.
II. The drying area:
The moisture content of peat that is being pelletized should be 8-12%. During the process of peat drying it is possible to use a number of different types of drying machines, but they should comply to certain specifications due to the high explosibility of peat dust. It also should be noted that the drying of peat can be conducted only indirectly, that is when the smoke fumes warm up the environmental air which in its turn acts as a drying agent. After the process of drying is completed the raw material undergoes the final stage of fine grinding which takes place in hammer mills; the material thus processed is now ready to be delivered into the pellet mill.
III. The pelleting area:
This area is the "heart" of the pellet production; it is its final stage.
The dry ground peat is being pressed into the cylindrical pellets of a specified diameter. Right before the raw ground material gets into the pressing chamber it is being pre-processed with dry vapors which makes it more conformable to pressing; the bonding agents are also activated during this process. Fresh pellets contain excessive moisture; their temperature is about 80°С; they are also excessively fragile; due to all these factors they are being sent to the next processing stage, which is cooling. During the process of cooling not only the temperature of pellets drops to the environmental level but their moisture content reaches the standardized level as well. After the pellets have been hardened, the small particles which have formed during the work cycle’ transportation of pellets are being removed from their bulk; thus the pellets acquire their "trade dress".
IV. The packaging area:
Heat stations and boiler houses are the end users of the peat pellets; the latter are being delivered into their premises in large containers or in bulk in railway cars. Depending on the type of an enterprise’s transportation infrastructure the finished product can be dispatched in bulk in railway cars or by water transport or, alternatively, it can be pre-packed into soft "big bag" containers and sent by means of railway or motor transport. The record keeping of quantities of the material dispatched is also done in this area.