RU2251456C1 - Method for processing bitumenous roofing materials - Google Patents

Abstract

FIELD: recovery of waste roofing bitumen -containing materials.

SUBSTANCE: method comprises steps of preliminarily cutting material by pieces; feeding it to chamber of disintegrating apparatus; disintegrating material by means of dull cutters; sorting disintegrated material by bitumen powder and bitumen cardboard; at disintegration adding to material water in quantity consisting 1-15 mass % of processed material; providing high -speed rotation of cutters for creating fine-drop mist covering disintegrated material in order to eliminate its sticking onto inner surfaces of disintegrating chamber; trapping dust-like bitumen formed at disintegration process and melting it together with bitumen powder and simultaneously dehydrating it. It is possible to dissolve detergent in water.

EFFECT: lowered cost price of bitumen processing procedure.

2 cl, 1 dwg, 2 tbl

Description

The method relates to the field of construction, and more particularly to the disposal of used roofing. Processing products can find application in repair and construction work on roofs, as well as in road repairs and the production of new bitumen-containing materials.

There is a method of processing bitumen roll materials, in which the latter is loaded into a container and kept in the presence of hot bitumen until the coating mass is separated from the base (RF patent No. 2148599, IPC С 08 L 95/00, С 10 С 3/10, publ. 10.05. 2000 BI No. 13). The basis of the roll bitumen material in the implementation of this method is burned using heat to heat the tank with bitumen.

The disadvantage of this method is that it allows you to select and use only the bitumen component of the rolled materials due to the loss of the burned base.

A known method of extracting bitumen from roofing materials (RF patent No. 2117532, IPC B 03 V 9/02, published on 08.20.1998, BI No. 23 (part II), in which roofing materials are crushed, placed in a tank with heated bitumen-solvent substance , emit bitumen and remove insoluble solids.

The above method is carried out using various solvents of bitumen, which makes it harmful to the health of staff. In addition, it is energy-intensive enough, which increases the cost of final products.

A device for grinding bitumen-containing materials is also known (utility model No. 311111, IPC В 02 С 13/14, published on July 20, 2003, BI No. 20). The processing method carried out on this installation includes preliminary cutting of the ruberoid carpet into pieces, grinding pieces with the simultaneous separation of bitumen in the form of crumbs and separation of bitumen and base.

The described method is feasible only at ambient temperatures not higher than 10 ° C, at which the bitumen remains solid and retains its brittle properties. At temperatures above 10 ° C, bitumen softens. Bitumen sticks to the internal surfaces of the grinding chamber, as a result of which the installation becomes impossible. A feature of roofing is the fact that they can be carried out in the presence of plus temperatures. As a result of this, the waste of bitumen materials in the form of old roof coverings appears in large quantities precisely in the warm season. Therefore, the material is preliminarily cooled in the warm season. The cooling process is long, energy-intensive and inefficient. The need for cooling the material increases the energy intensity of the method, which in turn increases the cost of the final product. In addition, the operation of the installation is accompanied by dust formation, which adversely affects the health of staff.

The invention solves the problem of reducing the cost of the processing of bituminous rolled materials at an ambient temperature of more than 10 ° C and improving working conditions.

This task is achieved by the fact that in the method of processing bituminous roofing materials, including its preliminary cutting, feeding into the grinder chamber, grinding with blunt knives, sorting the crushed material into bituminous powder and bitumen cardboard, water is added in the amount of 1-15% to the grinding stage from the mass of the processed material, while providing high-speed rotation of the knives to create a fine droplet mist enveloping crushed material, excluding its sticking to the internal surface awns shredder chamber, catch formed during grinding pulverulent bitumen, which together with the bituminous powder was subjected to melting simultaneously with its dehydration.

Detergent can be dissolved in water.

The separated bitumen powder is fed to a bitumen smelter, where moisture is evaporated during bitumen remelting. In addition, pulverized bitumen is captured from the air stream coming after sorting and sent for re-melting.

Water or a solution of detergents are added in order to eliminate the sticking of bitumen material that appears at temperatures above 10 ° C. It is known that sticking can be reduced by lyophobization of the surface, i.e. weakening of the molecular interaction of contacting surfaces. For this purpose, water or various surfactants are used. The surfactant is adsorbed from the solution on the surface of the bitumen material, grinders and grinding chamber and leads to facilitation of the installation and the stability of the entire process. Detergents that are used to add to water contain surfactants.

The proposed method allows for the disposal of bitumen roofing materials all year round, while significantly reducing the energy intensity of the entire processing process. Additives of water or detergent solutions do not adversely affect the final products and do not change their consumer properties. At the same time, these additives greatly facilitate the grinding process, improving the operation of grinding tools, as well as improving the working conditions of maintenance personnel, as the dust content of the environment is reduced.

Graphic material attached to the description contains the installation diagram, which allows you to implement the proposed method in practice.

The following notation is used in the diagram:

1 - machine for cutting large layers of material into separate pieces; 2 - belt conveyor; 3 - chopper; 4 - a container with an aqueous solution of detergents; 5 - pump; 6 - pipeline; 7 - a casing; 8 - sieve; 9 - a hopper for collecting bitumen powder; 10 - a bin for collecting bituminized cardboard; 11 - a casing; 12 - installation for the collection of crushed bitumen; 13 - a hopper for the accumulation of crushed bitumen; 14 - pipe for removal of purified air; 15 - bitumen smelting installation.

A specific example of the method

The layers of the old roofing coating are cut on a machine 1 with a saw blade into pieces of approximately 300x300 mm. On the conveyor belt 2, the cut pieces are fed into the receiving neck of the grinder 3, in which they are mechanically broken and crushed by rotating blunt knives. The mass of simultaneously processed material during the experiments was 2 tons. At the same time, water was supplied to the grinder from the tank 4 by the pump 5 through the pipe 6. From high-speed rotation of the knives in the grinder, water turns into a fine droplet mist that envelops crushed material, excluding its sticking to the inner surfaces of the grinder chamber.

The dependence of water flow on ambient temperature has been experimentally established. The results are shown in table 1.

Table 1. Ambient temperature, ° С Water consumption,% by weight of bitumen materials 10 - eleven 1 fifteen 3 twenty 5 25 8 thirty 12 35 fifteen 40 25

The above data correspond to the minimum required amount of water at a certain temperature for a stable process.

Reducing the amount of water leads to periodic clogging of the calibrating grinder mesh, a significant increase in cleaning and maintenance time, unstable operation and reduced productivity.

At temperatures of 40 ° C and higher, water consumption is significantly increased, because the viscosity of bitumen increases sharply, and the working conditions of maintenance personnel deteriorate and cease to comply with sanitary standards. Therefore, the implementation of the process at temperatures above 35 ° C is impractical.

It was experimentally established that the addition of detergent to water can reduce the amount of water, as shown in table 2.

table 2 Ambient temperature, ° С Water consumption,% by weight of bitumen materials The amount of detergent added,% of the amount of water 10 - - eleven 0.9 0.15 fifteen 2.7 0.3 twenty 4,5 0.45 25 7.2 0.6 thirty 10.8 0.85 35 13.5 1,0 40 25 1,5

The use of detergent additives (in the example, Russian-made detergent “Aist” was used), as can be seen from the table, can reduce water consumption and, as a result, reduce energy costs during subsequent dehydration during remelting. Moreover, the addition of a small amount of detergents does not adversely affect the consumer properties of the obtained bitumen. An increase in the concentration of detergent is economically unreasonable because the technological process proceeds stably with the data indicated in the table, which is confirmed by repeated experiments.

A decrease in the amount of solution or its concentration leads to periodic clogging of the gauge grid, a significant increase in the time for cleaning and maintenance, unstable operation and a decrease in productivity.

An increase in the amount of added solution compared to the tabular data leads to additional energy costs for the subsequent evaporation of water during remelting.

The pieces of material received in the grinder are crushed with knives.

When the pieces hit the knives, the coating mass of bitumen is simultaneously separated from the cardboard base and the bitumen is transformed into a fine-grained material - bitumen powder, and the cardboard base is torn into small pieces. Next, the crushed material passes through a calibrating grid and by gravity due to vertical movement under its own weight and due to the air flow created by the rotating knives, through the casing 7 enters the rotating sieve 8. On the sieve, bitumen and cardboard are separated into fractions and the bitumen powder is accumulated in the hopper 9 and bituminized cardboard - in the hopper 10. Dusty bitumen enters with the air stream through the casing 11 into the installation for the collection of crushed bitumen 12 and accumulates in the hopper 13. The cleaned air comes out from the pipe 14. Bitumen powder is loaded into a bitumen melting plant 15, where it is remelted and water is evaporated. Ready secondary bitumen is poured into bags or briquettes. After the spill of bitumen, a bitumen-mineral sludge is discharged from the bitumen smelter.

The proposed method of processing roofing bitumen materials ensures their 100% recycling.

As a result of recycling, the following materials are obtained:

- secondary bitumen - 60%;

- bituminized cardboard - 30% (used for pressing piece goods used in the repair of the roof, and the manufacture of a number of roll materials, as well as bituminous tiles);

- bitumen-mineral smelting smelting - 10% (goes to the manufacture of asphalt tiles and other products).

The production line occupies approximately 150 m ² . The cost of secondary bitumen is 50% of the cost of new. Tests of the obtained material confirmed its high quality.

Claims (2)

1. A method of processing bitumen roofing materials, including its preliminary cutting, feeding into the grinder chamber, grinding with blunt knives, sorting the crushed material into bituminous powder and bituminous cardboard, characterized in that at the grinding stage water is added in the amount of 1-15% of the mass of the processed material, while providing a high-speed rotation of the knives to create a fine droplet mist enveloping crushed material, excluding its sticking to the inner surfaces of the chamber chitelya, catch formed during grinding pulverulent bitumen, which together with the bituminous powder was subjected to melting simultaneously with its dehydration. 2. The method according to claim 1, characterized in that the detergent is dissolved in water.