MX2014002336A - Portable probe for extracting and cooling powder samples dragged by gases at high temperatures. - Google Patents

Abstract

The present invention refers to a portable probe for extracting powder samples from the inner portion of ducts and cyclones where said particles are moved at high speed and temperature, maintaining said samples in a confined environment and free of pollution with the purpose of carrying out a sampling and process control that ensure the quality of the corresponding products. Taking the cement industry as example, it is of substantial importance taking samples in the different steps of the manufacturing process, where it is required to collect the samples and maintain them in a specific atmosphere for avoiding pollution thereof.

Description

Portable probe for the extraction and cooling of samples of dust entrained by gasses at high temperatures.

OBJECT OF THE INVENTION The present invention relates to a portable probe that allows the taking and cooling of samples of powders inside ducts and cyclones where said particles are moved by gases at high speed and temperature, in order to carry out sampling and process control using the probe of the present invention that allows to assure the quality of the corresponding products.

Taking the cement industry as an example; where small particles moved by gases at high speed and temperature are handled, it is of vital importance to take samples in the different stages of the manufacturing process for quality assurance. For this, it is necessary to carry out the collection of the samples and keep them in accelerated cooling within a CO2 atmosphere to avoid contamination for further physical-chemical analysis.

BACKGROUND Many are the industrial processes where the quality control of the particles requires special sampling devices, which have been developed mainly empirically and specifically for each requirement and process.

There are inventions on the subject, such as the patents of the United States numbers: 4,772,454; 5,063,789; 5,490,429; 5,718,512; 5,777,241; 1,809,325; 3,643,508 and 3,938,390, related to the sampling of gases under different conditions and for various applications: continuous gas analyzers for high temperature furnaces, samplers for gases for blast furnaces and other metallurgical furnaces, devices for extracting samples and measuring the degree of environmental contamination, some of these inventions justify their large dimensional size due to the inclusion of cooling systems.

Other inventions focus their design on sample systems for the gases produced by the combustion of the rotary kiln, some of them even treat a part of the volatile gases, specifically chlorine and sulfur; as well as for the removal of the lead present in the powder as the patents of the United States numbers: 7,789,944 B2; 4,059,019; 4,276,092 and patent applications 2008/0092739 and 2011/0083745 Al. These designs and functions are different from those of the present invention.

Likewise, Mexican patent application MX / a / 2013/012106 of the same inventors, is a similar antecedent to the present invention.

State of the current sampling technique.

In the cement manufacturing industry, currently the operational technique practiced for the collection of the samples is carried out in the cielon of the fourth stage of the preheater (19) shown in Figures 5 and 6.

The procedure for this maneuver is completely manual and the device used is of simple design. It consists of a handle with a cylindrical container at its lower end; the operation begins with the opening of the access hatch (20), to then introduce the device, where the hot powder is obtained. It is precisely the conditions in which the sampling is carried out, the opening of the hatch, which allows the contamination of the sample.

This sampling involves the induction of air into the interior of the cyclone, prior to the furnace; This income is called "false air". It is an undesired condition, since it directly affects the process of decarbonation, induces an oxidizing condition to a medium at high temperature, without oxygen and rich in CO2 from the horizontal rotary furnace (21).

In summary, the sampling carried out is contaminated, since it reacts with the oxygen of the air when it is extracted, which affects and modifies the present phases.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a side view of the probe of the present invention where its main components are shown.Figure 2 is an isometric view of the detail of the extraction tube (5), the side tube (7), the particle inlet hole (6) and the safety cylinder and stop (17).

Figure 3 is a drawing of a longitudinal section of the cooling tube (9) and the screen holder tube (12) where you can see the cone of the cooling tube (8) that joins both tubes and also the lid of the screen holder (15), the gas outlet slots (13) and one of the screens (22).

Figure 4 is a drawing showing the configuration of the CO2 inlet pivots. The first (3) is placed in the direction tangent to the inlet tube (1) and the second (10) to the cone of the cooling tube (8). Also, the extraction tube (5) is observed where very close to its external end is the entrance hole (6).

Figure 5 is a drawing showing the flow of raw material for the manufacture of cement within the preheater system, this flow is represented by a continuous arrow (-?), As well as the flow of gases at high temperature is represented by a broken arrow (?).

Figure 6 is a photograph showing the extraction of samples in the traditional way during the manufacture of cement. i 4 DETAILED DESCRIPTION OF THE INVENTION The portable probe of the present invention is based on the principles of fluid dynamics, specifically on the Bernoulli principle; which is related to the change in pressure of a moving fluid with respect to the change in speed, applied in the present invention to generate a pressure difference favorable to the safe extraction of the samples contained in the industrial process equipment that allows the taking of samples of particles inside the ducts where said particles are moved by gases, CO2 for the cement industry, at speeds of 40 to 80 meters per second (m / s) and temperatures between 700 and 1200 ° C, particularly for the control of quality in the production of cement, keeping said samples in a confined and unpolluted environment in order to carry out a process control that ensures the quality of the corresponding products.

Said probe is comprised of an inlet tube (1) which is an elongated cylindrical body having its closed upper end (2), as shown in figures 1 and 4, immediately below its upper end is attached to a first C02 inlet pivot (3) which is positioned tangentially to the wall of the inlet tube (1) at an angle of 25 ° to 42 ° from the horizontal plane. The entrance tube (1), at the end of the first quarter of its length, joins at an angle of 90 ° with a collector tube (5) of its same diameter.

The collection tube (5), is a cylindrical tube with a length of one to two meters, closed at its front end (23) and has on its wall, immediately before its front end, with a circular hole (6) of a diameter of the order of between one eighth and one twelfth of the diameter of said collector tube (5) as can be seen in figure 2.

Beside the collector tube (5) runs a side tube (7) of smaller diameter than the collector tube, open at its front end (24) and connected at its rear end (4) to a differential pressure transducer (not shown). in the figures) where we obtain the internal pressure (P) of the cielon (19).

The lower end of the inlet tube (1) is joined to a cone of the cooling tube (8) which is connected to a cooling tube (9) that has a larger diameter than the inlet tube (1). The cone of the cooling tube (8) is connected tangentially to half the length of said cone (8) and parallel to the first CO2 inlet pivot (3), a second input pivot of C02 (10) with An angle of 25 ° to 42 ° from the horizontal plane.

As can be seen in figure 3, the lower part of the cooling tube (9), it is connected to the upper part of a second conical section (11) which in turn connects its lower part to a sieve tube (12) of greater diameter than the cooling tube (9). This screen holder tube (12) in its lower part has a plurality of gas outlet slots (13) that only leave four small square sections (14) that allow the connection of this screen holder tube (12) with a conical cover (15) that closes the system. Inside the sieve tube (12) there is at least one screen (22).

The sieve tube (12) on its inner wall has at least four metallic eyebrows (25) in all its circumference and equidistant from each other, which support the sieves (22) which are porous structures of flattened circular shape placed perpendicular to the length of the sieve tube (12). These sieves range from 325, 400, 450, 500 and up to 635 mesh according to the ASTM E-ll Standard (American Society of Testing Materials).

In the dry-process method of preheating and precalcining, the raw powder is fed (18) to a heat exchanger or pre-heater that progressively heats the homogeneous mixture to temperatures between 950 and 1000 ° C. This preheater is a system that consists of 4 to 6 cascade cyclones that are inside a reinforced concrete tower, with heights that exceed one hundred meters (Figure 5). In this process the crude is dried, dehydrated and finally decarbonized.

The heating of the crude oil is carried out by heat exchange between the hot rising gases coming from the combustion in the rotary kiln (21), represented in Figure 5, as indicated above, by discontinuous arrows, and the raw material descending, represented in this same figure by continuous arrows that runs through the exchanger.

Then the crude enters the horizontal rotary kiln (21), which is basically a cylindrical tube with variable dimensions; Its length ranges between 45 and 80 meters with an internal diameter of 3 to 5 meters, rotating at approximately 3 rpm in an uninterrupted manner.

In the interior of the rotary kiln the controlled combustion of fuels takes place, reaching flame temperatures above 2,200 ° C.

Once inside the oven, the oil continues to increase its temperature between 900 and 1000 ° C until reaching the maximum of 1,450 ° C, the temperature necessary for the correct formation of the components responsible for the known mechanical properties of the cement. The material that produces the oven has the appearance of rounded granules and is known as "clinker", to preserve the crystalline structure and stabilize the components present in the cyclones, which in this phase of the process are in a range of 500 to 900 ° C, the clinker must be cooled quickly in a time between 0.5 and 1 sec. up to a temperature between 50 and 30 ° C.

Figure 6 shows the traditional way of obtaining the samples during the manufacture of cement.

Method of operation of the sample extraction probe of the present invention The sample extraction hatch (20) of the cyclone (19) has a gate with a geometry that allows only the entrance of the extraction tube (5) and the side tube (7) of the extraction probe in a single orientation that force the circular hole (6) to face the flow of the cyclone.

The extraction tube is introduced through the sample extraction hatch (20) into the cranium until the safety cylinder and stop (17), which surrounds the collection tube (5) and the side tube (7) until the safety cylinder and stop (17) touch the gate to prevent the entry of air into the cyclone and control the penetration of the extraction tube (5) into the cyclone.

A flow of CO2 is passed through the first (3) and second (10) input pivots of C0 at a pressure of 3 to 20 atmospheres of equal magnitude to both pivots. The objective of the application of C02 is to be used as a fluid for the generation of low pressures due to the venturi effect that it generates, drag gas and dust protection gas. The position of each pivot causes the C02 to flow helically to generate a low pressure in the extraction pipe (5) obtained when the gas passes at high speed through the inlet pipe (1), where the Bernoulli effect occurs. On the other hand, the sample dust that rotates inside the cyclone enters the probe through the circular hole (6) of the collection tube (5). This orifice is placed facing the direction of the flow of the dust particles inside the cyclone and when the dust particle enters through this hole it is braked by impact on the internal wall of the collection tube (5). Once the powder has been braked, it remains under the action of low pressure due to the Bernoulli effect described above. This pressure, being lower than that inside the cyclone, generates a suction effect that takes it from the extraction tube (5) to the inlet tube (1). A second helical effect is generated by supplying C02 for the second input pivot of C02 (10). The primary objective is to cause the dust particles arriving from the inlet tube (1) to follow the same helical path towards the cooling tube (9) to increase the residence time, cool down and reinforce the generation of the low pressure. In this way, the application of a second cold C02 flow in the cooling cone (11), the sudden change of volume of the mixture of dust particles with the entrained gas and the helical path inside the cooling tube ( 9) produces a rapid cooling keeping the original structure of these dust particles that are inside the cyclones. In this way, the chemical-crystallographic analysis carried out on said extracted dust particles with the probe of the present invention it will be as representative as possible of the samples that are at high temperature and in a CO2 atmosphere inside the cielon.

From here the dust particles pass to a new volumetric expansion by means of the second conical section (11) to the screen holder tube (12) where they are captured by the screens (22) while the C02 gases leave the screen holder tube ( 12) through the gas outlet slots (13). After the gas outlet slots is the conical lid (15) that closes the system and is removable to be able to place or extract the sieves (22).

The cooling of the sample is carried out due to the injection of C02 by the first and second input pivots of C02 which carries out the thermal dissipation of the powders. From here the powders pass through the second conical section to the screen holder tube where the powders are captured and the CO 2 rich gases are released through the gas outlet slots.

Claims (5)

REINDIVICATIONS

1) A portable probe for the extraction of samples of dust entrained by gases at high temperatures, characterized in that it comprises an inlet tube (1) which is an elongated cylindrical body having its closed upper end (2); immediately below its upper end is attached to a first CO2 inlet pivot (3) which is positioned tangentially to the wall of the inlet tube (1) at an angle of 25 ° to 42 ° from the horizontal plane; the entrance tube (1), at the end of the first quarter of its length, joins with a collector tube (5) of its same diameter at an angle of 90 °; the collection tube (5), is a cylindrical tube with a length of one to two meters, closed at its front end (23) and has on its wall, immediately before its front end, with a circular hole (6) of a diameter of the order of between one eighth and one twelfth of the diameter of said collector tube (5); next to the collector tube (5) runs a side tube (7) of smaller diameter than the collector tube, open at its front end (24) and connected by its rear end (4) to a differential pressure transducer where we obtain the internal pressure (P) of the cielon (19); the lower end of the inlet tube (1) is joined to a cone of the cooling tube (8) that connects to a cooling tube (9) of greater diameter than the inlet tube (1); the cone of the cooling tube (8) is connected tangentially to half the length of said cone and parallel to the first input pivot of C02 (3), a second input pivot of C02 (10) with an angle of 25 ° to 42 ° from the horizontal plane; the lower part of the cooling tube (9) is connected to the upper part of a second conical section (11) which in turn connects on its lower part to a sieve tube (12) of larger diameter than the cooling tube; This screen holder tube (12) in its lower part has gas outlet slots (13) that only leave four small square sections (14) that allow the connection of this screen holder tube (12) with a conical cover (15) ) that closes the system.

2) The portable probe for the extraction of samples of dust entrained by gases at high temperatures, according to claim 1, characterized in that at least one sieve (22) supported by a metallic eyebrow is located inside the screen carrying tube (12). (25)

3) The portable probe for the extraction of samples of dust entrained by gases at high temperatures, according to claim 2, characterized in that the CO2 carries out a suction effect based on the Bernoulli principle between the inlet pipe (1) and the collection tube (4), allowing the collection of the sample and also serving as a drag gas, cooling the dust in collection and providing a protective atmosphere for the sample before being analyzed in the laboratory.

4) The portable probe for the extraction of samples of powders entrained by gases at high temperatures, according to claims 1 and 2, characterized in that the powders are trapped by the sieve (s) (11).

5) The portable probe for the extraction of samples of dust entrained by gases at high temperatures, according to claims 1, 2 and 4, characterized in that the stainless steel screens occupy the entire area of the circumference of the screen holder tube (12) .