RU102945U1 - DEVICE FOR PRODUCING MODIFIED BITUMINOUS AND BITUMINO-POLYMERIC MASKS - Google Patents

Abstract

The utility model is intended for the production of modified bitumen and bitumen-polymer mastics and can be used in conjunction with existing mixing machines and plants. The technical result is to reduce the time to obtain modified bitumen and bitumen-polymer mastics, as well as to obtain homogeneous modified bitumen and bitumen-polymer mastics. The technical result is achieved by the fact that the device contains a thermally insulated body, in which a curved pipe is placed, which transfers the reaction mixture to obtain modified bitumen and bitumen-polymer mastics, a heat carrier and a heating device for the said heat carrier, while the curved pipe in at least two places is made with inserts that reduce its cross section. 6 c.p. f-ly, 6 ill.

Description

The utility model is intended for the production of modified bitumen and bitumen-polymer mastics and can be used in conjunction with existing mixing machines and plants.

In the preparation of modified bitumen or bitumen-polymer mastics, the uniform distribution over the entire volume of the initial components - bitumen and modifying additives, as well as uniform heating of the reaction mixture is of great importance. The rate of reactions of bitumen modification and the quality of the resulting product (uniformity of properties throughout the volume of the modified bitumen mastic) depend on this.

To obtain the reaction mixture from bitumen and modifying additives, mixing devices are used. Various mixing methods and mixing devices are known:

- Steel enameled apparatuses (reactors), are intended for carrying out various chemical processes in aggressive liquids with heating or cooling and mixing of the medium; and

- Tanks with pipelines and valves to mix the reaction mixture using a pump.

In the reactors for mixing the reaction mixture, various mixing devices-mixers are used: paddle, frame, anchor, turbine, belt, drum, disk, which produce mixing of the reaction mixture in a horizontal plane. When mixing with these mixers, it is not always possible to obtain a uniform distribution of modifying additives in bitumen due to the different specific gravity of these additives. Additives with a higher specific gravity gradually move to the lower layers of bitumen, and with a lower specific gravity to the upper ones. Therefore, the finished modified bitumen mastic does not have uniform properties throughout the volume.

The tanks are mixed by repeatedly exchanging the volume of the reaction mixture from the bottom of the tank to the top, i.e. in the vertical plane. Due to the presence of stagnant zones in the tank, where the exchange occurs less intensively, when mixing with a pump, it is also not possible to obtain a uniform distribution of modifying additives.

A known installation for producing bitumen-polymer materials (RU 2264251, publ. 20.11.2005), comprising an apparatus with a mixing device with a pipe for supplying a gas phase, an external circulation circuit, consisting of lines of polymer solution and vapor, while the polymer solution line is additionally equipped apparatus with a mixing device in the form of a paddle mixer mounted on a shaft made hollow and forming a channel for supplying a gas phase.

This installation implements a method of mixing using a paddle mixer in a reactor with a jacket for the coolant. Additionally applied the supply of the gas phase due to the shaft of the paddle mixer, made hollow and forming a channel for supplying the gas phase. The gas phase is supplied to increase the viscosity of bitumen-polymer materials. This installation has the disadvantages that a reactor with a mixing device has: uneven distribution of the components of the reaction mixture, uneven properties of the bitumen-polymer material throughout the reactor volume.

A known installation for producing modified bitumen (RU 2152474, publ. 10.07.2000), containing dosing devices, mixers and pumps for pumping the finished product, each mixer is equipped with a planetary carrier, at one end of which there is a screw, on the other - frame mixers, as well as an additional gear pump connected to the mixer by a recirculation pipe.

This installation allows to obtain modified bitumen with good properties in the uniform distribution of the components of the bitumen reaction mixture, when the specific gravities of the mixed components differ from the specific gravity of bitumen by ± 25%. With a more significant difference in the specific weights of the components and bitumen, the distribution of the components in the bitumen in the vertical plane of the mixer will not be uniform. It is also difficult to achieve a uniform temperature of the reaction mixture throughout the entire volume of the mixer, so the chemical modification of bitumen in different temperature layers will not occur the same.

In the industrial production of modified bitumen mastics, large tanks and reactors are used in which the reaction mixture is mixed and heated to carry out chemical reactions of bitumen modification. Using well-known methods of mixing and devices that implement them, it is not possible to obtain a uniform temperature of the reaction mixture throughout the volume, which leads to uneven properties of the modified bitumen mastics.

The purpose of this utility model is to create a device that will allow for uniform distribution of temperature and modifying components in a bitumen reaction mixture to reduce the preparation time of modified bitumen and bitumen-polymer mastics and to obtain more uniform properties of bitumen mastics (in terms of the volume of batch produced).

This problem is solved using the developed device, in which they carry out:

- mixing modifying additives in bitumen by creating a turbulence in the flow of the reaction mixture; and

- short-term increased thermal effect on the reaction mixture.

The main principle of the device according to this utility model is the formation of turbulence in the flow of the reaction mixture by creating:

- changing the direction of flow of the reaction mixture;

- a temperature gradient over the cross section of the flow of the reaction mixture; and

- periodic changes in the flow area of the reaction mixture over the cross section.

Figure 1 is a top view of a device according to the present utility model.

Figure 2 is a front view of a device according to the present utility model.

Figures 3, 4 and 5 are corresponding sections and cross-section shown in Figure 1.

6 is a flat electric heater.

A device for producing modified bitumen and bitumen-polymer mastics contains a thermally insulated metal body (1), in which a curved metal pipe (2) is placed, which transfers the reaction mixture to obtain modified bitumen and bitumen-polymer mastics, a coolant (3) and a device (4) ) heating said coolant (3). When sequentially supplying components to the reaction bitumen mixture, the bent pipe (2) in each straight section contains at least two inserts (5), while simultaneously feeding the components, at least three inserts (5), which reduce its cross section. Figure 1 shows the 13 mentioned places with inserts (5). Typically, said inserts (5) are made in segments.

The device of this utility model has an expansion metal tank (6) mounted on top, for receiving the coolant in case of its thermal expansion due to elevated temperature. As a heat carrier (3), I-40 oil can be used.

The device according to this utility model implements a new principle of mixing in the preparation of modified bitumen mastics - the creation of turbulence in the flow of the reaction mixture, due to which intensive mixing is performed.

The turbulence of the flow is created by changing the direction of movement of the reaction mixture along the curved pipe (2) and using inserts (5), which are located both in different places of the said curved pipe (2), and in different parts of the circle obtained in cross section at said location (Fig. .3). In addition, turbulence in the flow of the reaction mixture occurs due to the creation of a temperature gradient over the cross section of the bent pipe (2): on the outer surface of the bent pipe (2), the temperature is maintained from 160 ° C to 180 ° C with the heat carrier, while the incoming bitumen reaction mixture has a temperature of 120 ° C-130 ° C. During the passage of the reaction mixture through the device according to the present utility model, due to the aforementioned turbulence, intensive uniform mixing of the modifying additives and bitumen occurs.

During the experimental work, it was found that the optimal price-quality ratio for the Activator device is achieved by using a bent pipe (2) with a length in the range from 20 m to 30 m with a diameter of 50 mm to 150 mm, which has a configuration shown in figure 1.

To reduce the time to obtain modified bitumen mastics in the device according to this utility model, a pulsed (short-term) thermal effect on the reaction mixture is produced. Due to this effect, the activation of chemical reactions in the reaction mixture occurs, because temperature increase is a catalytic effect for the modification of bitumen. The thermal effect is created by placing a bent pipe (2) in a thermally insulated metal case (1) with a heat carrier (3) (I-40 oil), which is heated using a heating device (4). The temperature of the coolant (3) is maintained in the range from 160 ° C to 180 ° C. This temperature range produces a catalytic effect on the course of chemical reactions in the bitumen reaction mixture and does not degrade bitumen and its constituents used in the modification of bitumen and the preparation of bitumen-polymer mastics. Technically, this is achieved by using temperature sensors that are placed in the medium (3), and control circuits for supplying electricity to the heating device (4). As the heating device (4), flat electric heaters SKP-100-80 / 15 220 (SKP - indirect flat resistance) can be used, the contact leads of which are made as threaded rods under the nut M5 (Figure 6).

The transit time of the reaction mixture through the device according to the present utility model depends on the length of the bent pipe (2) and the performance of the pump pumping the reaction mixture through it. The range of optimal flow rate of the reaction mixture to create turbulence lies in the range from 0.8 m / s to 1.2 m / s. At this flow rate, the residence time of the reaction mixture in the device according to the present utility model is from 15 seconds to 60 seconds. During this short time of increased heat exposure to the reaction mixture, no destruction of bitumen and modifying components occurs. Short-term thermal effect produces a catalytic effect on the course of chemical reactions of modification of bitumen.

Claims (7)

1. Device for producing modified bitumen and bitumen-polymer mastics, containing a thermally insulated body, in which are placed: a curved pipe through which the reaction mixture flows in the process of obtaining modified bitumen and bitumen-polymer mastics, a coolant and a heating device for the said coolant, while a curved pipe at each of its straight sections, at least in two places, is made with an insert that reduces its cross section. 2. The device according to claim 1, characterized in that it further comprises an expansion metal tank for receiving a coolant in case of its thermal expansion due to elevated temperature. 3. The device according to claim 1, characterized in that the temperature of the coolant is from 160 ° C to 180 ° C. 4. The device according to claim 1, characterized in that the curved pipe is made in length from 20 m to 30 m, and its diameter is from 50 mm to 150 mm. 5. The device according to claim 1 or 4, characterized in that the flow rate in the said bent pipe of the reaction mixture to obtain modified bitumen and bitumen-polymer mastics is from 0.8 m / s to 1.2 m / s, and the residence time in said pipeline, said mixture stream is from 15 s to 60 s. 6. The device according to claim 1, characterized in that the said insert is made in the form of segments. 7. The device according to claim 1, characterized in that said heating device is a flat electric heater.