RU2369633C2 - Method of briquette manufacture - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: method may be used in briquette pressing technology to produce vegetable oil and oil cakes as briquettes. It is useful for wood and wood-working industry waste treatment to produce qualitative and environmentally friendly fuel briquettes free from binding substances. They can be used for treating oil cakes and disperse wastes in coil industry. Initially, milling zone is consequently formed in extrusion channel between zones of initial raw material loading and tapered pressing screw. Then pre-pressing zone and heating zones are generated due to internal friction forces, where excess moisture is squeezed and removed from extrusion channel through its walls, which are permeable for steam and liquid. The required commercial parametres for briquettes made from each type of raw materials are chosen based on combination of screw rotation speed, variable amounts of supplied raw materials, variable clearances between internal tapered surface of extrusion channel and external tapered surfaces of pre-pressing and heating screw, and external tapered surfaces of tapered pressing screw.

EFFECT: method allows for producing qualitative briquettes from different types of raw materials.

1 dwg

Description

The invention relates to mechanical engineering and can be used in the construction of screw press extruders designed for the processing of various types of bulk and fibrous materials, mainly for the manufacture of briquettes for various purposes by pressing and screw extrusion. The method can be widely used in the processing of waste from the forestry and woodworking industries, agricultural wastes, peat, sludge and particulate waste in the coal industry to produce high-quality fuel briquettes for domestic needs, as well as for briquetting similar raw materials for solving other national economic problems.

Known for extensive scientific, technical and patent information on this issue. The article by V.F. Annenkov et al., “The Light of Furniture and Wood” (1999, Nos. 3-4, p.24-26) presents the results of the development of a technology for producing high-calorie fuel briquettes from waste wood with peat additives.

In the journal of the Russian Federation “Inventors - Engineering" (2001, No. 2, pp. 18-20) published information on three developments: 1) a method for producing solid fuel in the form of briquettes, granules based on precipitation of municipal wastewater for use in boiler plants, at thermal power plants , in the furnaces of railway cars; 2) the manufacturing technology of moisture-resistant fuel briquette in the fuel industry from waste from the coal mining industry; 3) technologies for producing briquetted fuel from hydrocarbon sludge and dispersed coal waste. There are also known presses, both hydraulic and screw, of the German company Nestro Lufttechnik GrBH (info@nestro.de) for pressing sawdust, agricultural processing waste, metal shavings, etc. This press equipment is rather metal-intensive and energy-consuming, and also works on so-called “dry” raw materials, the moisture content of which does not exceed 10-12%.

A large number of patents from different countries are known for methods and screw press extruders for the production of vegetable oil and oilcake from oil-containing raw materials according to classification headings B30B 9/12, 9/16, 9/26, etc., C11B 1/06 (see, for example , patents of Ukraine: No. 46873, V30V 9/02, 1/11 1/11 bull. No. 7, 2000; No. 63029, 9/16 B30V, C11B 1/06, No. 2, 2003; No. 63203, 9/16 , bull. No. 1, 2004; No. 73905, B30B 9/02, 9/14, bull. No. 9, 2005; No. 76532, B30V 9/12, 9/08, bull. No. 12, 2005).

According to the patent of Ukraine No. 38877 (B27N 3/00, 3/08, bull. No. 4, 2001) for the method of manufacturing fuel briquettes from waste wood, the waste is pre-dried to a moisture content of 8-10%. A whole mini-plant for the pyrolysis destruction of worn-out car tires is offered. The resulting gas mixture is burned to heat the following batches of destructible rubber products, and wood waste is dried using an air-gas mixture in a drum dryer at a temperature of 220-250 ° C.

According to the patent of the Russian Federation No. 2185420 (published on July 20, 2002) for the method of producing fuel briquettes and a plant for pressing them, the problem of industrial processing of woodworking waste in the production of environmentally friendly fuel briquettes for domestic needs is solved. The method includes grinding, drying, mixing the components and subsequent pressing. Wood waste is crushed to a size of not more than half the free space of the screw grooves to fractions of about 30 mm, then dried to a moisture content of 18-20%, and then crushed into shavings 1-8 mm long. The final drying to a moisture content of 3-7% is carried out without oxygen at a temperature of 180-210 ° C, then pressed at a temperature of 190-250 ° C into briquettes with a density of 1150-1400 kg / m ³ , on which a protective coating of paraffin is applied.

According to the patent of the Russian Federation No. 2046821 for a method of manufacturing fuel briquettes, wood waste is crushed, treated with superheated water vapor with a temperature up to 300 ° C of a layer of wood waste particles with a size of 0.4-11 mm in the steam filtering mode and the subsequent pressing of fuel briquettes, and when processing it is used superheated steam with a temperature of 100-300 ° C and its filtration rate through the waste layer of approximately 2.5 m / s.

As a prototype, which coincides with the claimed decision on purpose and significant features, in terms of the method, a workable screw press extruder was adopted, an advertising and technical description and a general view of which are given in the Russian journal “Inventor and Rationalizer”, No. 10, 2006, as successful exhibit at the exhibition "Lesdrevbummash" in Moscow. There is a “Operating Instructions for KD 50-4013.000.000” for the indicated extruder, developed by PKB TPO Novosibirskmestprom. The extruder is manufactured in series by LLC Centaur, Russia, 400042, Volgograd, Aviatorov Highway, tel. 8-10-7-844-296-39-69, allows you to get high-quality briquettes from sawdust with an initial moisture content of up to 15% with a capacity of up to 500 kg of products per hour without binders. The press is equipped with an electric heater on the forming part, which allows firing the surface of the resulting briquette at a temperature of 200-300 ° C. Products obtained using this press have a density of 1100-1200 kg / m ³ , are resistant to indirect exposure to atmospheric moisture and can be stored for a long time in storage rooms without losing their original shape. During combustion, they do not decompose into components, burning like coke fuel. The disadvantages of the prototype include the following:

- the inability to use raw materials with a degree of humidity of more than 12-15%, since the briquette shape stability is violated, it breaks, and “shots” of the pressed material are possible due to accumulation of steam in the working chamber / use of an electric heater to warm the extrudable mass to a temperature of 200-300 ° FROM;

- narrow specialization of a screw press, designed for processing only dry sawdust from waste wood flooring using sawdust up to 4 mm in oak wood;

lack of adjustment of pressing pressure and screw rotation speed;

- the press extruder, despite its rather small dimensions, has a weight of about 1 ton and power ratio of 50 kW.

Common features of the method of pressing according to the claimed solution and prototype are the following operations-operations:

- load the feedstock into the hopper with a dispenser;

- promote the raw material along the length of the extrusion channel with a rotating feed screw;

- the processed mass is heated:

- compaction occurs on the conical section of the extrusion channel by a pressing screw through a forming matrix into a briquette with a central cylindrical hole along its axis.

The basis of the invention is the task of improving the known method for producing high-quality briquettes from various types of raw materials suitable for briquetting by modifying the extrusion modes along the channel length of the screw press extruder in terms of flow, pressure and temperature of the processed mass, depending on its physical and mechanical characteristics at any initial degree of humidity. This eliminates the need for preliminary drying of the raw material to a value of 10-12%, eliminates the need for the use of electric heating of raw materials, reduces the requirements for the special strength of the used body parts and, therefore, reduces its material consumption. At the same time, it is possible to universally use modified screw press extruders for processing the expanded raw material base of dispersed waste suitable for obtaining durable briquettes, as well as using a press extruder in the processing of oil-containing raw materials to produce oil and meal in the form of briquettes.

The solution to this problem is due to the fact that in the method for producing briquettes, which includes loading the feedstock into a hopper with a dispenser, advancing the processed mass of raw materials along the length of the press channel with a rotating feeding screw, heating the processed mass and compacting it with a pressing screw on the conical section of the channel through the forming matrix into the briquette with a cylindrical hole along its axis, according to the invention, in the extrusion channel in addition between the feed zone of the feedstock and the zone of the conical pressing screw is followed First, the grinding zone is formed first, and then the zone of preliminary pressing and heating of the processed mass due to internal friction forces, in which the excess moisture is pressed and removed from the channel cavity through walls permeable to liquid and vapor, and the required consumer parameters of briquettes from each type raw materials are selected by a combination of the screw rotational speed, the amount of raw material supplied by the dispenser, the gaps between the inner conical surface of the extrusion channel and outer conical surfaces of the screw pre-pressing and heating of the processed mass, as well as the outer surfaces of the turns of the conical pressing screw.

The listed features in the general formulations of the method constitute the essence of the invention, since they are necessary in any implementation of the invention and sufficient to achieve the task.

A specific difference of the proposed method for producing briquettes is that when using raw materials of high humidity and various physical and mechanical properties, to remove excess moisture, the corresponding shaft drive rotation speed, the amount of raw material supplied by the dispenser, and the corresponding clearance between the conical surfaces of the screws and the working chamber are set to obtain the required temperature of pressing and density of the resulting briquette.

The essence of the proposed invention is illustrated by a drawing of a structural diagram of a press extruder, where;

1 - drive based on an electric motor;

2 - loading hopper with dispenser (not shown);

3 - press body;

4 - a shaft connected to the screw;

5 - feed screw;

6 - chamber with holes (slotted grain chamber);

7 - chopping screw;

8 - screw pre-pressing and heating the mass;

9 - conical pressing screw;

10 - forming matrix;

11 - a working chamber installed with the possibility of movement along the axis;

12 - support press;

13 - pressed product (briquette) with a hole along its axis.

The device operates as follows. Raw material, such as sawdust or wood shavings, is fed into hopper 2, with an almost unlimited degree of humidity and a size of less than half the cross section of the feed screw groove, which, with the help of a dispenser (not shown in the figure), located in hopper 2, flows onto feed screw 5 located on the shaft 4, driven by rotation of the drive 1. In the chamber 6, the raw material is additionally crushed, heated by internal friction to a temperature of 100-400 ° C and pre-pressed by screws 7 and 8, while excess moisture is squeezed out and its removal through the grain openings in the chamber 6 in the form of drops and steam. Next, the mass enters the pressing screw 9 located in the chamber 11, where the final pressing of the mass occurs. At the exit from the chamber, there is a forming matrix that gives the desired shape of the briquette (circle, square, hexagon, etc.). The final part of the pressing screw in the form of a cone allows you to form a central hole in the briquette up to a diameter of 25 mm, which creates an additional opportunity for the exit of excess moisture. The pressing temperature for raw materials of various humidity and density is selected in the range of 150-300 ° C, which leads to the release of resinous substances in the wood, while the briquette after cooling is additionally compounded with these resins and becomes resistant to atmospheric moisture during storage.

For the selected shaft rotation speed, due to the specific moisture content in the feedstock, the degree of heating of the processed feed and the density of the resulting briquette is controlled by changing the gap between the pressing screw 9, made in the form of a cone, the end cone of the pre-pressing screw 8 and the inner surface of the working chamber, mating with the surfaces of the screws 8 and 9. The change in the gap is provided by moving the working chamber 11 using a threaded control device and a latch along and the drive shaft.

Briquettes were obtained from wood sawdust and sunflower husks according to TU U 10.3-14063949-001-2001, having the following characteristics.

The initial moisture content of the raw materials is 25-35%, determined according to GOST 11305.

Round section: outer diameter 60 mm, central hole with a diameter of 18-20 mm.

Correct hexagon: large diagonal 61 mm, central hole 18-20 mm.

The density of briquettes in both cases was 1100-1260 kg / m ³ .

Calorific value during combustion, determined according to GOST 147, was:

sawdust 4000-4800 kcal / kg (16.76-20.11 MJ / kg),

sunflower husk 4800-5200 kcal / kg (20.11-21.79 MJ / kg).

The mass fraction of total moisture in the briquette 1 hour after pressing at atmospheric humidity of not more than 90% was no more than 8-10%, which corresponds to the above technical conditions in Ukraine for fuel briquettes from agricultural waste.

The bulk nodules of aluminosilicates used for steel deoxidation were also pressed. The density of the monolithic briquette was about 3500 kg / m ³ .

Thus, the claimed method for producing briquettes meets the regulatory requirements for novelty, inventive step and industrial applicability.

Claims (1)

A method of producing briquettes, including loading the feedstock into a hopper with a dispenser, moving the feedstock along the length of the internal channel of the screw press with a rotating feeding screw, compacting and heating the processed mass with a pressing screw on a conical section of the channel through a forming matrix into a briquette with a cylindrical hole along its axis, characterized in that in the extrusion channel, additionally, in the interval between the feed zone of the feedstock and the zone of the conical pressing screw, the grinding zone is first formed grinding, and then the pre-pressing and heating zone of the processed mass due to internal friction forces, which simultaneously squeeze excess moisture and remove it from the cavity of the extrusion channel through its walls that are permeable to steam and liquid, and the required consumer parameters of briquettes from each type of raw material are selected a combination of the screw rotation speed, a change in the amount of feed, a change in the gaps between the inner conical surface of the extrusion channel and the outer nical surfaces of turns of the screw pre-pressing and heating the processed mass and the outer conical surfaces of the conical piston screw turns.

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