per century high technology and progressive materials, some long-used raw materials do not lose their leading positions, remaining as in demand as before. This group is represented by many categories of construction and household goods, including waste from woodworking enterprises.

sawdust packed in bags

What are sawdust?

The most accessible and inexpensive raw material with a wide range of applications. Represents the crushed shavings of beige color, particles of small fraction which are formed in the form of the remains of sawing up of wood. Moreover, they should not be confused with wood chips, which are obtained on purpose.

Physicochemical characteristics

This is a lightweight material with a bulk density of about 220-580 kg per cubic meter, depending on the level of humidity (standard - from 8% to 15% and above). It reaches a size of no more than 50 mm with a dry windage coefficient of 0.13-0.8 units.

Contains about 27% lignin (a substance that gives plants a state of lignification) and 70% cellulose, hemicellulose (actually carbohydrates). The ratio of chemical components is distributed as follows:

• nitrogen - 0.1%;
• hydrogen - 6%;
• oxygen - 44%;
• carbon - 50%.

The basic properties, differences and characteristics of chopped wood are described in GOST 23246-78, which regulates this species raw materials. The main terms and definitions of this material are also indicated there.

Characteristics of sawdust

Such material knows no analogues and is characterized as the most:

• environmentally friendly (does not cause allergies, does not produce harmful emissions, is completely natural);
• cheap (in fact, you only have to invest in shipping, since most sawmills give it away for nothing
• as waste)
• heat-saving (remarkably insulates the room from cold bridges, in which it is not inferior to mineral wool).

What are sawdust for?

They are recognized as inexpensive and affordable raw materials, therefore they are used in various national industries and specialized areas. Where are they most in demand? Priority activities include:

• fertilizer;
• warming;
• mulching;
• heating (fuel);
• smoking;
• construction.

They are also used for bedding in livestock breeding and keeping pets, are used in furniture production, are used for the manufacture of various building materials (pressed, cement-water mixture). And they also serve to produce cardboard, paper, some types of plastics, linoleum and all kinds of facing plates.

sawdust as insulation

They have played this role for a long time, because they differ high level bulk density. To eliminate their main disadvantages (flammability, combustibility and the risk of rodents), raw materials are subjected to special treatment before use, for which:

1. Mixed with gypsum, cement, clay or lime;
2. Sprayed with a solution blue vitriol.

An example of home insulation with sawdust

As a result, the material becomes fireproof, suitable for insulating both utility buildings and residential buildings.

sawdust for fertilizer

When mixed with straw or peat (and sometimes in their natural form) they become an excellent medium for mycelium. Such a substrate for growing champignons and oyster mushrooms contains all the necessary elements and perfectly retains moisture, protects mushroom cultures from temperature extremes.

Using sawdust as fertilizer

When introduced into the soil, wood waste greatly improves its quality characteristics, perfectly replacing unsafe substances.

Mulching

They are in high demand in rural and domestic crop production as a covering and mulching agent. Suitable for laying soil around bushes, trees, seedlings, because:

• positively influence the development of plantings;
• protect the surface of the earth from erosion;
• protect the trunks from the difference in daily temperature;
• prevent evaporation of moisture;
• inhibit the development of weeds.

Mulching example

sawdust as fuel

Heating is another function of this raw material. Being the wood residue of sawmill work, it is often used to produce special pellets (pellets) and briquettes that are used in fuel boilers. Small particles are pressed under high pressure to make it easier to burn, store and transport them.

fuel briquette

sawdust in construction

Mixed with water, cement, gypsum or clay, they increase the strength properties, becoming an ideal building material. Here are a few varieties:

• sawdust concrete - high-quality fire-resistant bricks or blocks based on cement, sand and softwood waste;
• sawdust boards - insulation from sawdust, carboxymethylcellulose (glue) and antiseptic-fire retardant;
• wood block - a heat insulator based on copper sulphate, cement and fine wood pulp;
• paykerite - composite blocks from chopped / crushed waste wood and water; malleable, durable, slowly melting;
• wood concrete - lightweight concrete obtained by mixing organic filler and chemical additives with cement.

The use of sawdust blocks in construction

Furniture manufacture

They often go to the manufacture of various sets and single pieces of furniture. They are mainly pressed into chipboard and fiberboard, allowing you to get a variety of designs for household interior items. Thus, they perfectly replace solid wood, which requires much more complex processing processes.

sawdust for smoking

For this, the remains of certain tree species are recommended so that the products do not have unpleasant bitterness. Dry waste of alder, oak, beech and any fruit trees, cleaned of dust, is especially suitable for such a procedure. They can be used both separately and in a mixture in order to obtain a more refined taste.

Logistics

Due to its high airiness and lightness, this material is widely used in the field of transportation. Serves as a shock absorber, preventing fragile goods from coming into contact with hard objects. Perfectly preserves objects during transportation over any distance.

STATE STANDARD OF THE UNION OF THE SSR

WOOD SHREDD

TERMS AND DEFINITIONS

GOST 23246-78

USSR STATE COMMITTEE ON STANDARDS

Moscow

DEVELOPED by the Ministry of Forestry and Woodworking Industry of the USSR

PERFORMERS

M. A. Medvedeva, V. M. Cherezova, V. R. Radkevich

INTRODUCED by the Ministry of Forestry and Woodworking Industry of the USSR

Deputy minister V. F. Zaretsky

APPROVED AND INTRODUCED BY Decree State Committee USSR according to the standards of August 11, 1978 No. 2188

STATE STANDARD OF THE UNION OF THE SSR

By the Decree of the State Committee of Standards of the Council of Ministers of the USSR dated August 11, 1978 No. 2188, the deadline for the introduction was established

from 01.07.1979

The standard establishes the terms and definitions of concepts used in science and industry related to chopped wood.

The terms established by this standard are mandatory for use in all types of documentation used in the national economy: scientific, technical, educational and reference literature. The above definitions can, if necessary, be changed in the form of presentation, without violating the boundaries of concepts.

There is one standardized term for each concept. The use of terms - synonyms of the standardized term is prohibited.

The standard provides an alphabetical index of the terms it contains.

Term	Definition
TYPES OF SHREDDED WOOD
1. Wood particles	According to GOST 18110-72
2. Chopped wood	Wood particles of various shapes and sizes, obtained as a result of mechanical processing. Note . Chopped wood includes: chips, crushed wood, shavings, sawdust, wood flour, wood dust
3. Chips	By -77
4. Technological chips	By -77
5. Green wood chips	Chips containing impurities of bark, needles and (or) leaves
6. Fuel chips	By -77
7. Crusher	Wood particles obtained by grinding wood in crushers and hammer mills
8. Wood shavings	Fine wood particles formed when wood is cut
9. Wood sawdust	Small particles of wood formed during the sawing process
10. Technological sawdust	Sawdust suitable for the production of cellulose, wood-based panels and products of wood chemical and hydrolysis industries
11. Wood flour	Wood particles of a given granulometric composition, obtained by dry mechanical grinding of wood
12. Wood dust	Unsorted wood particles smaller than 1 mm
DIMENSIONAL AND QUALITATIVE CHARACTERISTICS OF SHREDDED WOOD
13. Wood particle length	According to GOST 18110-72
14. Wood particle width	According to GOST 18110-72
15. Wood particle thickness	According to GOST 18110-72
16. Wood particle cut	The surface of a wood particle obtained by cutting wood
17. Wood grain cutting angle	The angle formed by the cut surface and the direction of the fibers
18. Fraction of chopped wood	A collection of wood particles that are close in their geometric dimensions
19. Fractional composition of chopped wood	Particle ratio certain sizes in the total mass of chopped wood
20. Large fraction of chopped wood	The set of wood particles remaining on the sieve with the largest (in accordance with the requirements) flow area of ​​the sieve openings of sorting devices
21. Standard fraction of chopped wood	A set of wood particles, the size of which meets the requirements for chopped wood, depending on its further use
22. Fine fraction of chopped wood	The set of wood particles that have passed through the sieve of sorting devices, on which the conditioned fraction is retained
23. Screening	A set of wood particles that pass through all sections of the sieve openings and are collected on a pallet of sorting devices
24. Species composition of chopped wood	The quantitative ratio of chopped wood of different species
25. Foreign matter	The presence in the total mass of crushed wood particles of non-wood origin. Note . Foreign impurities include: metal and mineral impurities
26. An admixture of rot	The presence in the total mass of chopped wood of particles affected by rot
27. Admixture of bark	The presence of bark particles in the total mass of chopped wood
PROPERTIES OF SHREDDED WOOD
28. Bulk density of chopped wood	The ratio of the mass of chopped wood to its volume
29. Full wood factor	The ratio of the volume of wood to the volume of chopped wood obtained from it
30. Compaction of chopped wood	Reduction of the initial volume due to mechanical influences
31. The degree of compaction of chopped wood	The ratio of the difference between the bulk and compacted volumes to the compacted
32. Compaction coefficient of chopped wood	Ratio of bulk volume to compacted volume
33. Freezing of chopped wood	The property of wet particles to form large pieces under the influence of negative air temperature
34. Flowability of chopped wood	The property of particles of crushed wood to spontaneously crumble under the influence of gravity
35. Caking of chopped wood	The property of particles of crushed wood to lose flowability under the influence of moisture, particle shape, mass and duration of storage
36. Arching of chopped wood	The property of crushed wood to form vaults during storage
37. Moisture content of chopped wood	Mass fraction of water in chopped wood

TU RB 100725266.005-2003

WOOD SAWDIES FOR FUEL NEEDS

Specifications

TU RB 100725266.005-2003

Introduced for the first time

These specifications apply to sawdust for fuel needs from coniferous and hardwood, hereinafter referred to as "wood sawdust", intended for use as fuel for the generation of heat and / or electric energy.

Symbol when ordering:

"Wood sawdust TU RB 100725266.005-2003".

Technical requirements

1.1 Wood sawdust must comply with the requirements of these specifications.

1.2 Wood sawdust in terms of quality must comply with the standards specified in table 1.

Table 1

The name of indicators		Test method
Mass fraction of total moisture in wood sawdust (W r i),%, no more
* Ash content (А d), %, no more
** Net calorific value of sawdust (Q r i), kJ/kg, not less than
Mass fraction of sulfur, %, no more
Mass fraction of chlorine, %, no more
Mass fraction of bark, %, no more	not standardized
Mass fraction of rot, %, no more	not standardized
Breed composition	not standardized
Dimensions, mm, no more
Mass fraction of mineral impurities, %, no more
* excluding mineral impurities ** is taken at the moisture content and ash content of wood sawdust, excluding mineral impurities

Note - By agreement with the consumer, sawdust may contain chips and / or shavings.

1.3 The content of radionuclides in sawdust should not exceed the national permissible levels approved by the Ministry of Health of the Republic of Belarus

1.4 Determining the volume of sawdust wood is carried out in accordance with " Guidelines to determine the volume of secondary wood resources. Moscow, 1988”. The density of wood sawdust, depending on the species composition and storage method, is given in Table A.1 of Appendix A.

1.5 Wood sawdust is supplied without packaging, in bulk.

2 Safety requirements

Wood sawdust in direct contact does not have a harmful effect on the human body. Working with them does not require special precautions.

The maximum permissible concentration of wood dust at workplaces is 6 mg/m 3 , the fourth hazard class. The frequency of air control of the working area in accordance with San PiN 11-19-94.

Wood sawdust is a combustible material. Their storage must comply with the requirements of the rules fire safety Republic of Belarus for logging, woodworking, pulp and paper and wood chemical production facilities PPB 2.07. Fire and explosion hazards are given in tables A.2, A.3 of Appendix A.

3 Environmental requirements

3.1 In order to protect the atmospheric air from pollution by industrial emissions, including from the combustion of sawdust, constant monitoring of compliance with MPE or EAM should be organized in accordance with GOST 17.2.3.01.

3.2 The content of pollutants in flue gases should not exceed the standards given in Table B.1 of Appendix B.

3.3 Secondary waste from incineration - ash is allowed to be used as fertilizer, subject to a chemical analysis for the content of toxic substances and heavy metals in it and the establishment of its hazard class. Ash application rates are determined in each specific case by calculation and should not cause the accumulation of heavy metals in the soil above 0.7 - 0.8 MPC according to the translocation indicator.

Permissible levels of elements in the soil according to the translocation indicator are given in Table B.2 of Appendix B.

3.4 In other cases, the ash is subject to disposal in accordance with the procedure established by the legislation of the Republic of Belarus in the field of waste management.

4 Acceptance rules

4.1 Wood sawdust is accepted in batches. A batch is considered to be any number of wood sawdust of the same purpose, executed with one document certifying their compliance with the requirements of these technical specifications and containing:

Name of the manufacturer, its subordination (ministry, association) and location;

Trademark of the manufacturer (if any);

Volume in dense cubic meters;

Designation of these technical conditions;

Storage conditions;

Signature of the person responsible for acceptance.

4.2 When checking the quality of sawdust, selective control is used according to GOST 15815. 10 point samples with a total mass of (101) kg are taken from different places of the batch or at regular intervals in the process of uniform loading (unloading) of vehicles.

4.3 Control tests are carried out according to the following indicators: the content of radionuclides of cesium-137, mass fraction of total moisture, ash content, calorific value, mass fraction of sulfur, mass fraction of chlorine, mass fraction of mineral impurities.

4.4 If the quality of the primary sample during verification does not meet the requirements of these specifications, a new primary sample is re-verified from a double number of incremental samples taken from the same lot. The recheck results apply to the entire lot.

If the results of the re-check are unsatisfactory, the entire batch of wood sawdust is rejected.

4.5 The consumer has the right to carry out a control check of the compliance of the quality of sawdust with wood standards of these technical specifications, while observing the sampling rules and control methods provided for by these technical specifications.

4.6 Wood sawdust is accounted for in cubic meters of dense mass, rounded up to 0.1 m 3. The following coefficients are used to convert the bulk volume of wood sawdust into dense volume during transportation by road:

0.35 - on the territory of the supplier;

0.36 - on the territory of the consumer when transporting sawdust over a distance of up to 50 km;

0.37 - on the territory of the consumer when transporting sawdust over a distance of more than 50 km;

0.43 - on the territory of the supplier and the consumer when using pneumatic loaders to load sawdust into transport containers.

It is allowed to record wood sawdust by the weight method with subsequent conversion into dense cubic meters.

Control methods

5.1 The mass of wood sawdust is determined on a balance according to GOST 24104.

5.2 Sampling and processing of samples to check the quality of sawdust is carried out in accordance with GOST 15815.

5.3 The measurement of the content of radionuclides is carried out according to the methods for performing measurements, approved in the prescribed manner.

5.4 Definition mass fraction moisture is carried out according to GOST 11305.

5.5 The determination of the ash content is carried out according to GOST 11022.

5.6 The determination of the calorific value is carried out according to GOST 147.

5.7 The determination of sulfur is carried out according to GOST 2059.

5.8 Determination of chlorine is carried out according to GOST 9326.

5.9 Determination of the mass fraction of mineral impurities in wood sawdust is carried out according to GOST 18320.

Transportation and storage

6.1 Wood sawdust is transported by all means of transport. Transportation is carried out in accordance with the rules for the carriage of goods in force on the type of transport used. Vehicles must be pre-cleaned of foreign matter.

6.2 When transported in open vehicles, sawdust must be covered with a tarpaulin, film or other materials that protect them from loss and clogging.

6.3 The storage location must be determined by the approved scheme of technological production.

6.4 Open storage of wood sawdust is allowed in heaps no more than 5 m high and no more than 10 m wide with the steepness of the natural slope of the stored materials for two months in summer and three months in winter.

6.5 Sawdust storage according to GOST 9014.0.

6.6 Storage conditions should exclude the impact of atmospheric precipitation, groundwater and wastewater.

GOST 18320-78

Group K13

STATE STANDARD OF THE UNION OF THE SSR

TECHNOLOGICAL WOOD SAWDIES FOR HYDROLYSIS

Specifications

Technological wooden sawdust for hydrolysis.
Specifications

Introduction date 1980-01-01

INTRODUCED BY Decree of the USSR State Committee for Standards dated August 2, 1978 N 2083

By the Decree of the State Standard of 02.28.84 N 679, the validity period was extended until 01.01.90 *
______________
* The limitation of the validity period was removed according to protocol N 4-93 of the Interstate Council for Standardization, Metrology and Certification (IUS N 4, 1994). - Note "CODE".

INSTEAD OF GOST 18320-73

REPUBLICATION (December 1985) with Amendment No. 1 approved in March 1985 (IUS 6-85).


This standard applies to sawdust obtained by sawing wood and intended for hydrolysis production.

The standard does not apply to sawdust obtained by cutting plywood, fibreboard and chipboard, plastics and other materials containing resins.

1. TECHNICAL REQUIREMENTS

1. TECHNICAL REQUIREMENTS

1.1. Depending on the purpose, the species composition of sawdust must correspond to that indicated in the table.

Purpose of sawdust (profile)
	conifers (all breeds)	hardwood (all species)	mixed (all breeds)
			coniferous	deciduous
alcohol			At least 70	No more than 30
yeast			Not regulated
furfural	Not allowed		Not allowed

1.2. Wood sawdust should not contain more than 8% bark, 5% rot and 0.5% mineral impurities.

1.3. In sawdust, more than 10% of small wood particles that have passed through a sieve with holes with a diameter of 1 mm, and more than 5% of large particles remaining on a sieve with a diameter of 30 mm, are not allowed.

2. ACCEPTANCE RULES

2.1. Wood sawdust is presented for acceptance in batches. A batch is considered to be the number of sawdust of one purpose, drawn up by one quality document.

2.2. To check the content of bark, small and large wood particles in sawdust, 10 one-time samples weighing 0.8-1.0 kg are taken from different places of the batch.

2.3. The species composition of sawdust, the content of rot in them, mineral and metal impurities is determined by agreement between the manufacturer and the consumer. Samples are taken in accordance with clause 2.2.

2.4. If unsatisfactory results are obtained for at least one indicator, a second test is carried out on a double sample. The recheck results apply to the entire lot.

2.5. Wood sawdust is accounted for in cubic meters of dense mass, rounded up to 0.1.

To convert bulk volume into dense volume, the following coefficients are taken:

0.28 - before shipment to the consumer;

0.30 - during transportation by car at a distance of up to 5 km;

0.34 - when transported by road and by rail at a distance of 5 to 50 km;

0.36 - when transported by road and rail at a distance of 50 to 500 km;

0.38 - when transported by rail over a distance of more than 500 km.

When transporting sawdust by water, the conversion factor is set by agreement of the parties.

When sawdust is supplied to the consumer directly by conveyors, sawdust is accounted for using automatic scales of the LT or LTM type in units of mass, followed by conversion to volume units. In this case, the volume of sawdust () supplied for a certain period of time is calculated by the formula

where is the mass of sawdust supplied for a certain period of time at a given humidity, kg;

- weight of 1 m of wood at the same humidity, kg.

3. TEST METHODS

3.1. Determination of bark content in sawdust

3.1.1. Equipment





Tweezers

3.1.2. Conducting a test

One-time samples taken according to clause 2.2 are combined together, thoroughly mixed and reduced by quartering to a sample weighing 1.0-1.2 kg. The sample is weighed with an error of not more than 0.1 g and scattered on the table. From the sample, bark particles larger than sawdust are selected and weighed. After that, about 10 g of sawdust are taken from the sample, weighed with an error of not more than 0.01 g. Small particles of bark are taken from the newly obtained sample with tweezers and also weighed with an error of not more than 0.01 g.

3.1.3. Results processing

The bark content () in sawdust as a percentage with an error of not more than 0.1% is calculated by the formula

where is the weight of the sample, g;

- mass of large particles of the bark, g;

- weight of the new sample, g;

- mass of small particles of the bark, g.

3.2. Determination of rot content in sawdust

3.2.1. Equipment specified in clause 3.1.1.

3.2.2. Conducting a test

To carry out the test, about 10 g of sawdust are taken from the sample prepared in accordance with clause 3.1.2 and weighed with an error of not more than 0.01 g. Rot is selected from this mass of sawdust with tweezers and weighed with the same error.

3.2.3. Results processing

where is the weight of the sample, g;

- mass of rot particles, g.

3.3. Determination of the content of small and large particles in sawdust

3.3. Equipment

Mechanical sieve analyzer brand ALG-M.

A set of control sieves with holes with a diameter of 30, 5, 3, 2, 1 mm.

Scales with a weighing error of not more than 0.1 g.

3.3.2. Preparing for the test

The control sieves in the set are arranged according to the decreasing hole size.

A solid tray is installed under the set of sieves.

3.3.3. Conducting a test

To carry out the test, the sample prepared in accordance with clause 3.1.2, after selecting large particles of bark from it, is weighed and placed in the upper sieve of the set, previously installed on the movable base of the analyzer. A set of sieves is fixed with ties, the analyzer is turned on, and the sample is sieved for 3 minutes.

After the analyzer is completely stopped, the upper sieve and tray are removed and their contents are weighed separately.

3.3.4. Results processing

The content of small or large particles in sawdust () as a percentage with an error of not more than 0.1% is calculated by the formula

where is the weight of the sample, g;

is the mass of large or small wood particles, g.

3.4. Determination of the rock composition of sawdust

3.4.1. Equipment and reagents

Scales with a weighing error of not more than 0.01 g.

Porcelain or glass glass according to GOST 1770-74, with a capacity of 500 cm.

A glass made of monel metal or nylon mesh, with a capacity of 500 cm3.

Tweezers.

Glass stick.

Filter paper according to GOST 12026-76.

Hydrochloric acid according to GOST 3118-77, 12% solution.

Potassium permanganate according to GOST 20490-75, 1% solution.

Ammonia according to GOST 3760-79, 1% solution.

3.4.2. Conducting a test

For the test, 10 g of sawdust are selected, remaining on a sieve with holes with a diameter of 3 mm, when determining the content of fine particles according to clause 3.3. Wood sawdust is placed in a beaker made of monel-metal or nylon mesh, which is placed in a porcelain beaker, and filled with a 1% solution of potassium permanganate so that the entire sample is covered with the solution. After 2 minutes, the mesh cup is removed and the sawdust is washed with water to remove the solution. After that, the sample is treated for 2 minutes with a 12% hydrochloric acid solution and washed again. Then sawdust is treated with 1% ammonia solution for 1 min.

Hardwood sawdust treated in this way acquires a purple-red color, and coniferous wood - yellow.

After processing, sawdust is lightly pressed with filter paper, sorted by color and weighed.

Note. In the absence of a mesh cup made of monel-metal or nylon mesh, it is allowed to process the sample directly in a porcelain cup.

3.4.3. Results processing

The content of hardwood sawdust () as a percentage with an error of not more than 0.1% is calculated by the formula

where is the mass of hardwood sawdust, g;

- mass of sawdust conifers, G.

The content of softwood sawdust () as a percentage is determined by the formula

3.5. Determination of the content of mineral impurities in sawdust

3.5.1 Apparatus and reagents

Measuring cylinder according to GOST 1770-74, with a capacity of 100 cm.

Chemical glass according to GOST 25336-82, with a capacity of 250 cm.

Glass funnel according to GOST 25336-82.

Scales with a weighing error of not more than 0.01 g.

Zinc chloride according to GOST 4529-78 or a saturated solution of any salt with a density of 1.4-1.6 kg/m.

A device for determining the content of mineral impurities (see drawing).

Instrument for determining the content of mineral impurities

1 - glass cylinder; 2 - top plate; 3 - bottom plate; 4 - receiving funnel;
5 - rubber tube; 6 - clamp; 7 - rack; 8 - bolted connection; 9 - washer;
10 - hole for draining the suspension

The device consists of two plates made of organic glass fixed on a stand. A glass cylinder is fixed in the upper movable plate, and a receiving funnel with a rubber tube and a clamp is fixed in the lower plate. Before starting work, the cylinder must be aligned with the receiving funnel.

The plates are pressed against each other with a washer made of organic glass using a bolted connection.

To improve the sliding of the upper plate on the lower, the contacting sides of the plates are covered thin layer lanolin, petroleum jelly or other lubricant. The bottom plate has a hole for draining the suspension from the cylinder. Drainage is carried out by turning the upper plate around the axis of the bolt until the cylinder is aligned with the hole in the lower plate.

3.5.2. Conducting a test

To carry out the test, 2 g of sawdust are taken from a sample prepared in accordance with clause 3.1.2, dried to a constant weight and placed in the instrument cylinder, where about 70 cm 3 of zinc chloride solution or saturated salt solution with a density of 1.4-1 .6 kg/m.

The contents of the cylinder are mixed and the suspension is allowed to settle for 30 minutes.

After settling, the solution with sawdust is poured into a glass through a hole in the bottom plate. Through a rubber tube, a solution with mineral impurities is poured into another glass.

The funnel above the beaker is thoroughly rinsed with water. Mineral impurities are transferred to a funnel with a paper filter. The precipitate is washed twice with water. The filtrate is discarded, and the filter with mineral impurities is dried in an oven at 105 °C to constant weight and weighed.

3.5.3. Results processing

The rot content () in sawdust as a percentage with an error of not more than 0.1% is calculated by the formula

where is the mass of mineral impurities in 2 g of sawdust, g.

3.6. Determination of the content of metal impurities in sawdust

Determination of the content of metal impurities in a sample prepared in accordance with clause 3.1.2 is carried out visually without the use of a magnifying device.

4. TRANSPORT AND STORAGE

4.1. Wood sawdust is shipped in bulk. Transportation is carried out by all means of transport in accordance with the rules for the carriage of goods in force on the transport of this type. When transporting across railway minimum size party must be at least one wagon.

(Changed edition, Rev. N 1).

When transported in open vehicles sawdust must be protected from loss and contamination.

4.2. Each batch of sawdust must be accompanied by a quality document stating:

a) the name of the manufacturer, its location and trademark;

b) the name of the department or enterprise, in the system of which the manufacturer is included;

c) number of vehicles;

d) the amount of sawdust in dense m *;

e) appointment of sawdust;

e) the designation of this standard;

g) the period of storage of sawdust before shipment to the consumer (with long-term open storage);

h) date of departure;

4.3. Wood sawdust is stored in bunkers or in heaps in open areas. The storage period should not exceed seven months.

The text of the document is verified by:
official publication
M.: Publishing house of standards, 1986

Requirements for the quality of sawdust used as a raw material in the production of fuel pellets

Technological sawdust must comply with GOST 18320-78.

Technological sawdust should not contain

more than - 8% bark

0.5% mineral impurities

from their volume.

More than 10% of small wood particles passing through a sieve with holes with a diameter of 1 mm and more than 5% of large particles remaining on a sieve with holes with a diameter of 30 mm are not allowed.

Metal inclusions in technological sawdust are not allowed.

Fractional composition of sawdust

The sawdust obtained on sawmill frames has a shape close to cubic. The main composition is 2-5 mm.

Machine sawdust has a fraction of 1-2 mm. Sawdust from wood processing circular saws(circular) have a fibrous structure.

Bulk weight and moisture content of sawdust

sawdust condition	Humidity rel. %	Bulk weight kg / m 3
Large fraction
wet natural
wet packed
Dry natural bulk
Dry compacted
Small fraction
wet natural
Dry natural bulk
Dry compacted
Chips and crushed wood
Small shavings
Dry natural bulk
Dry compacted
wood dust
conifers

Average density ( specific gravity) one dense cubic meter of wood at different absolute humidity (kg)

Absolute humidity, %

Filling factor of the overall volume

Waste types	Filling factors of the overall volume
Slabs, slats, cuts
Round waste (pencils)
Chips before transport
Chips after transportation
sawdust before transportation
sawdust after transportation

Accounting for technological sawdust is made in dense m 3 with an accuracy of 0.1 m 3. To do this, chips and sawdust from the bulk mass are converted into dense, by multiplying by the fill factor of the overall volume.

Sawdust transportation and storage

Each batch of sawdust must be accompanied by a quality document stating:

Name of the supplier company, its location.

Vehicle number.

The amount of sawdust in dense m 3.

Appointment of sawdust.

Shelf life of sawdust before shipment to the consumer (with long-term open storage).

Departure date.

The shelf life of sawdust should not exceed 7 months.

Open storage of sawdust stored in heaps

Distance from the surface of the pile to the measuring point (m)	Sawdust temperature (C 0)
	4-6 months

The highest temperature in heaps is observed for 4-6 months of storage.

The chemical composition of wood

The main organic substances that form the cell membrane of wood:

Cellulose.

• Hemicelluloses (pentosans, hexosans).

Radiological control

Radiometric measurements of samples for cesium 137 (Cs 137) stored at the enterprise technological sawdust should be carried out once every three months in the center of standardization and metrology with the issuance of a “Test Protocol” (Norm for Cs 137 = 1850 bq / kg).