MXPA98008138A - Equipment for the thermal treatment of bulk items in conveyors without - Google Patents

Abstract

The present invention relates to an equipment for the heat treatment of articles in bulk with an endless conveyor, which transports the material in bulk, and with which the infrared heat radiators are integrated in the zone for tempering (25), characterized in that the infrared heat radiators are installed on an endless shaft built to be permeable by radiation.

Description

EQUIPMENT FOR THE THERMAL TREATMENT OF BULK ITEMS IN CONTAINER CONVEYORS FIELD OF THE INVENTION The invention relates to equipment with which articles in bulk can be heat treated.

BACKGROUND OF THE INVENTION Many technical variations of auger conveyors are known, which solve thermal treatment tasks. Numerous devices are also known with which a thermal treatment is carried out applying thermal irradiation, with continuous transport, even of bulk articles. The transport equipment used works according to the principles of transport with belt, chains or vibration (according to DIN 15 201). The combination of endless transport with the application of heat of irradiation is known from German Patents DE-OS 19 06 278, DE-OS 19 22 230, and US Patents US 5,143,626 A and US 5,497,562 A. All the descriptions cited show the application of infrared heat radiators outside the periphery of the conveyor wave. This leads on the one hand to disadvantageous irradiation of pieces of the wave, on the other, the distance to the product to be irradiated agrees at least with the radius of the wave, with which the efficiency of the heat transfer is very limited . With US Pat. No. 4,430,057 A, it is proposed to transport a part of the product to be irradiated by paddles arranged in wave form near infrared irradiation sources. German Patent DE 23 41 331 A discloses a drum dryer, in which the wave of the wave is heated by hot combustion gases, these acting as a source of thermal radiation. The total irradiation power radiates radially throughout the periphery of the wave of the wave. The efficiency of this irradiation source is always limited by its low power density compared to electric infrared radiators, as well as by its characteristic vertex wavelength in the longwave infrared range (according to the IEC classification).

OBJECTIVES AND ADVANTAGES OF THE INVENTION The present invention is based on the objective of making possible a thermal treatment with deep effect of articles in bulk, from the point of view of the machinery technique, in continuous operation, in such a way that it can be To carry out a direct and rapid tempering of the articles in bulk, within temperature intervals that can be respected with great accuracy, with the shortest possible processing times. The heat treatment can be used for drying and / or for the directed modification of other physical or chemical properties of the material. The stated objective is achieved according to the invention by means of the properties of claims 1 or 2, the principle of endless transport being used for the transport of bulk articles and the application of heat for tempering the articles transported by thermal irradiation, during the transport in the endless conveyor or the endless tubular conveyor. Other embodiments and advantages of the invention are the subject of the sub-claims. By means of the invention, the following specific advantages of using an endless conveyor can be particularly obtained: - Because the transportation is based on thrust, a rotation of the material in general or even in the contact area of the material is carried out in bulk with the endless flank, with an effective thrust. This rotating effect is very marked on the endless conveyor, since here the grooved wall is moved. Through the rotation a homogeneous irradiation of the transported articles with thermal irradiation is promoted and, thus, a homogenous tempering. - Through a constructive division of the corresponding augers, in different types of zones, the steps of the hardening process can be united in a unit, to the steps of the process that have already been connected or are going to be connected, through technical machinery. For example, in this way it is possible to achieve an almost exact and even load of the temperance path in all the tempering processes. In the concept of vibratory transportation this is made possible with a pre-connection to a battery gear spout (eg British Patent Number GB 1 313 203). Apart from a specialized measuring zone, other zones of the auger which are suitable for the function will still be described throughout the description. Specific advantages of the application of tempering by thermal irradiation are particularly: - faster heat transfer to bulk items - deep effects of thermal irradiation, ie, bulk items are heated at least partly inside . This advantage of thermal irradiation is exploited in many ways, for example, in the plastics technique, since plastics, in principle of poor thermal conduction, can thus be tempered quickly by overcoming the obstacles of thermal convection. By combining the principles of endless transport with the transfer of heat by thermal irradiation according to the invention, a large number of problems in the tempering technique can be solved advantageously.

DETAILED DESCRIPTION OF THE INVENTION The invention will be shown in different modes of use with reference to the schematic drawings. Figure 1 schematically shows in cross section the placement of the infrared radiator (6) in the form of posts within the wave of the auger (2). In addition, the wave is hollow and has enough openings for the infrared rays to pass, so that they touch the article in bulk. To give an example, the auger is represented completely. The different types of auger, such as the band auger and the palette auger among others, which partly also provide the advantage of almost not hindering the passage of infrared rays to the bulk item, are also workable. The grooved walls of the auger and the auger itself will be produced with infrared reflectors or with a material that reflects infrared rays, such as aluminum, to increase the proportion of infrared rays received by the bulk item. Figure 2 shows a possible form of work in which a zone to be tempered and the so-called entry and measurement zones and are joined to the same auger. From a simple supply container (silo or similar) the material is passed through a funnel, first to an entire auger and then to a worked auger. In the entrance area 23, according to the processed volume, the exact amount of material to be filled in the hardening zone will be worked in during the work of the auger. In the measuring zone 24, which is after the entrance area 23, the processed volume is still being worked so that at the beginning of the zone for tempering 25 the degree of filling is the desired one. This way of implementing the invention is shown in Figure 2, where an endless conveyor is used as an example. A worm conveyor can also be used, and the function for the material must be carried out along the axis. With the material previously treated to be treated 21, the filling for the material 20 is carried out. The decrease can also be carried out just after the function for the material 20 or before the entrance zone 23 in a slow-step decrease in a fourth isolated From there it reaches the entrance area 23 that is in the start wave 22 of the installed auger. The start wave 22 drives the operation of the auger with three different functions at the same speed. Through the different works carried out by the augers in zones 22, 23 and 25, depending on where the material is located, different transportation speeds can be reached and therefore different functions can be performed. From the entrance area 23 the material passes to the measuring area 24, in which, depending on the function of the auger in terms of inclination, geometry and speed of the starting wave 22, it is ensured that it can only pass a limited amount of material up to the tempering zone 25 and to determine the degree of filling f in such a way for the loader for the installation 27, described below, is in any case free of material. Surely this will be reached at f = 0.02-0.15. In the zone for tempering 25, in this case a worm conveyor was chosen to handle the auger, in order to be able to expose the material without a protection through parts of the auger to the infrared rays and to maintain the absorption of the infrared rays by the transported elements as low as possible, since the conveyor surface is very small. In order to achieve this, a charger was installed for the installation 27 of the infrared radiator 28.

The magazine 27, as shown here, can only be stored in the solid store 33, but also, depending on the duration of the process, it can also be stored, as shown in this, in wave 22 that has a store 32 or it can also be stored several times. The height of the magazine 27, on the material, as well as on the deepest point of the conduit auger layer 26, is adjustable, in order to be able to maintain a control of the intensity of the infrared rays emitted by the infrared radiator 28 on the material. This adjustment on the material to be treated can be carried out at the start of this process or continuously alternatively through a meter of a non-contact temperature sensor 36 which, for example, is placed outside the auger layer. of conduit 26 or in the charger 27 and thus can measure the temperature. With the measuring signal, for example, influence on the height of the magazine 27 or on something else such as the specification of the size of the intensity of the radiation of the infrared rays acting on the material (such as the radiation temperature) can be influenced. , number of radiators on, etc.), so that the temperance corresponds to the specified points. The provisions for the loader installations 27 are carried, for example, with a flexible guide of the magazine 27 to the rack of the machine.

The material to be treated is transported through the tempering zone 25 and in this way the material passes through the treatment, as shown in the scheme, which is treated with an external material 29 and then with an external material. Through an exit slide 31 the material can be transported to the next step of the process. There may be a variation of the band auger 35, for example, which is composed of a hollow material, in which the heat can be introduced through a circulation system, to temper the auger in a stable manner and as an additional effect also to heat or, if necessary, to cool down the material that should be treated. The same is true for the auger portions of the measurement zones 24 and the input zones 23. The representation of FIG. 2 with a layer of closed conduit auger 26 gives us the convenient opportunity to absorb emissions (gases, dust). , with the hot air of the function for the material 20 and retain them in the filter, or as shown in Figure 2, absorb them in the entrance area of the auger with an absorption exhaust 36 and send them to a filtration or transportation equipment 37. In this way, the filtered and clean air can be thrown into the room 39, or through an air circulation circuit 38 it can be brought to the zone to be tempered 25 to be used again to temper and thus contribute to the saving of energy. The heat transported in the extraction can advantageously be used in the delivery zone 20, as well as in the inlet 23 and dosing area 24, to preheat the material. As well as the extraction of emissions 36, 27, in a simple manner for the expert, depression or overpressure can be applied in the process chamber. In specific applications, the corresponding installations can be optimally connected to a cooling system, these being at the same level as the transport element. The advantages achieved according to the invention can be observed, for example, in the drying of plastic granules. Advantages are also obtained in the treatment of other bulk items, such as fodder and many others. As side effects of the endless transport, in addition to a continuous process, the possibilities of coupling with other steps of the input or output dosing process, as well as the easy realization of encapsulation of the process space to record emissions and to apply a depression eventually advantageous.

Reference list 1 Wave housing, bottom 2 Wave 3 Wave housing 20 Material delivery 21 Material delivered 22 Wave drive shaft 23 Extraction zone 24 Measuring zone 25 Temper zone 26 Wave sleeve tube 27 Carrier for installation 28 Infrared radiator 29 Partially treated material 30 Fully treated material 31 Exit slide 32 Progressing housing with wave (22), adjustable height 33 Fixed housing, adjustable height 34 Non-contacting temperature sensor 35 Waveband 36 Removal of exhaust air or pressure load 37 Transport and filter unit or also vacuum pump or compressor 38 Air circulation 39 Air from escape out

Claims (11)

NOVELTY OF THE INVENTION Having described the above invention, it is considered as a novelty, and therefore, the content of the following is claimed as property: CLAIMS

1. Equipment for the heat treatment of bulk items with an endless conveyor, where, in the zone for tempering (25), an infrared heat radiator is integrated, characterized in that the infrared heat radiator is installed in a wave of the auger that lets the rays pass.

2. Equipment for the heat treatment of bulk items with an endless conveyor, where, in the zone for tempering 25, an infrared heat radiator is integrated, characterized in that the infrared heat radiators are installed in the conveyor endless following the principle of the endless belt or the endless conveyor in the central area.

3. Equipment according to claim 2, characterized in that: the infrared heat radiators are installed in the loader for installations (27) and because the height of the loaders can be adjusted.

4. Equipment according to claim 1, characterized in that: the endless conveyor contains, in the zone for hardening (25), a start zone (23) and / or a measuring zone ( 24).

5. Equipment according to claim 1 in any of claims 1 to 4, using a closed-wave jacket tube, characterized in that the extraction of the emissions from the process space and / or the application of a different atmospheric pressure to the from the middle, it takes place in the process space.

6. Equipment according to claim 1 wherein at least one of the preceding claims 1 to 5, characterized in that the thermal heat radiators are shaped and placed as rod-shaped elements.

7. An equipment according to claim 1, wherein at least one of the infrared heat radiators are installed, which can be operated separately.

8. Equipment according to claim 1, characterized in that the degree of filling of the conveyor wave (2) assigned to the tempering zone (25) can be adjusted.

9. An equipment according to claim 1 wherein at least one of the preceding claims 1 to 8, characterized in that the auger conveyor (2) and the grooved wall of the conveyor (9) are covered with an infrared reflector or because they are made with a material that reflects infrared rays.

10. Equipment according to claim 1, wherein at least one of the preceding claims 1 to 9, characterized in that the start zone (23) and / or the measuring zone (24) of the endless conveyor (2) are positioned, with respect to the volume produced, in such a way that it is possible to transport that quantity of articles in bulk corresponding to the degree of filling (f) of the endless conveyor (2) in the zone for tempering (25).

11. Equipment according to claim 1, wherein at least one of the preceding claims 1 to 10, characterized in that the endless conveyor (2) in the hardening zone (25) is positioned, according to its inclination and geometry, in such a manner that the degree of filling (f) can be adjusted between 0.02 and 0.15.