FI56368C - ROTARY EQUIPMENT FOR FRAMSTERING AV EN EXPENDITURE - Google Patents

Description

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JgSfA l J '1 UTLÄGGNINGSSKRIFT 00 * © ö • C (45) Patent granted 10 01 1980

Patent oeddelat v (51) Kv.ik. «/ Int.ci.« C 04 B 21/00 FINLAND —FINLAND (21) P »tanttlh“ kemu «- P * t * ntiM6knlni 780876 (22) H» k «ml »Pllvl —.An * eknln | td * g 20.03.78 (23) ALkupUvI - Glltlghätidag 06.08.70 (41) Tullut julklMkil - Bllvlt offantllg 20 03 78

Patent · and raklrtarlhallit (NlhtMtolpwon j. Month | in * date)

Patent · och registrctyrelsen Amttktn utlagd och utUkrtftan publkarad 28.09.79 (32) (33) (31) Pyydetty «uolkmi * —8 * f« rd priorlut 06.O8.69 Denmark-Danmark (DK) U228 / 69 (71) Leea Trading & Concession A / S, Vestergade 16, 1 ^ 56 K ^ benhavn K.,

Denmark-Danmark (DK) (72) Harry Kamstrup-Larsen, K ^ benhavn-Valby, Denmark-Danmark (DK) (7 * 0 SA Munsterhielm (5U) Rotary kiln equipment for the production of expanded clay product -Roterande ugnsanläggning för framställning av en expanderad l- produkt (62) The present invention relates to a rotary kiln apparatus for producing an expanded clay product, comprising a slow-rotating drying oven and a fast-rotating kiln and a transition zone connecting them.

Such an apparatus is known, for example, from DE publication 1 137 989 and SW publication 310 ^ -69. However, the former differs from the apparatus which is the subject of the invention already in that it lacks a common overflow zone connecting the drying and kiln. It is known to fit the latter, although not multi-part rotary kiln equipment, to the filling end of the tubular kiln inside the kiln wall and at a suitable distance therefrom an inner jacket of thermally conductive material so that hot flue gases can affect the clay material inside the kiln and the jacket. The sheath may be formed of iron bars running in a circular manner or longitudinal bars which together define the sheath surface. According to one embodiment, instead of the jacket, there may be inwardly directed, possibly oblique wings from the wall of the oven to keep the contents of the oven moving.

The object of the present invention is to provide a furnace apparatus which is mainly set out in the appended claim 1.

The heat transfer elements of the transition zone have a relatively high heat storage capacity, a high thermal conductivity and a large surface area and in this zone the clay material heated from the drying zone to 300-600 ° C over a relatively long time can be brought in a relatively short time, preferably 15-30 ° C. C to completely swell the granules of the clay product.

The pre-fired granules then have a fine expansion evenly distributed over the entire cross-section, in which, the ability to expand has been fully utilized. Due to the low bulk density, the kilns where drying and firing take place will operate more efficiently (higher m ^ amount of finished clay product / day) compared to the past, and this will know the improved production economy.

By forming the heat transfer members in the transition zone according to the invention, a very reliable heating of all the granules is achieved within a relatively short period of time, since the granules are heated on the one hand by the furnace lining and on the other hand by the heat transfer members. The furnace liner and said members are heated in a known manner by flue gas passing through the furnace. The heat transfer elements are efficient located near the furnace liner. The elements at the lowest point in the furnace are then located inside the grain filling of the furnace. The filling thus receives heat both from the outside and from the inside. The heating of the filling granules caused by the flue gas flowing over the filling is of negligible significance. It is crucial that the granules come into contact with the largest possible heating surfaces as the oven rotates.

With rod-shaped heat transfer members arranged according to the invention, it is possible, on the one hand, that the surface of the heat transfer members is particularly large and, on the other hand, that the granule filling is pushed upwards along the furnace liner.

According to the invention, the rods can be arranged in several, preferably two, layers. The rods of the inner layer may be at the intermediate spaces of the rods of the u-loosest layer. The distances between the rods can be 1-5 times as large as the diameter of one rod.

The diameter of the heat transfer members can be of the order of 20-60 mm. This size is appropriate given the usual size of the filling granules.

The heat transfer members may be made of steel, so that it is achievable that the members have a very high thermal conductivity while having a high mechanical strength. Preferably, so-called refractory steel is used.

The cross-section of the heat transfer members may further be rectangular and formed of, for example, flat strips.

Finally, according to the invention, the heat transfer members, viewed in the longitudinal direction of the furnace, can extend in said direction by 1 to 5 times the diameter of the furnace. Experiments have shown that at this length of members, the granules have to remain on the members for a suitably long time as the oven rotates at an angular speed of the order of 6 revolutions per minute.

The invention will now be described in more detail with reference to the accompanying drawings, in which

Figure 1 is a schematic view of a rotary kiln according to the invention;

Figure 2 is a longitudinal section of the furnace with the heat transfer members in the form of rods mounted thereon;

Fig. 3 is a quarter sectional view taken along line V-V of Fig. 2, showing the rods divided into one layer;

Figure 1 is a part of a support ring necessary to support the rods in two layers, and

Figure 5 is a part of a rod formed of flat rim iron.

The rotary kiln shown in Fig. 1 has a slowly rotating drying oven 1 and a fast rotating kiln 2. The clay material is filled from the right end opening 3 of the kiln and as the clay rolls e-way in the drying zone it disintegrates to form granules. Drying is carried out by passing hot flue gas to the outlet 6 of the kiln 2, and this flue gas thus passes to the right in countercurrent to the granular clay product. Between the opening 3 and the point at the left end of the kiln 1 the clay product is heated only slowly at about 20 ° C. To 300 ° C. After passing M, the granules meet the heat transfer members arranged in the vicinity of the furnace liner. These members, which will be described in more detail below, may extend over a greater or lesser part of the length of the furnace, but not beyond point 5 a short distance from the furnace feed end 7. Between points * + and 5, i.e. in the transition zone indicated by A in the figure, the granules are heated , which is considerably larger than before, because they now heat from about 300 ° C to about 1150 to 1175 ° 0 in about 15 to 30 minutes. After passing step 5, the high temperature is maintained for about 7 minutes, after which the temperature is lowered. Said rapid heating thus obtained causes the expansion capacity of the granules to be fully utilized. Cracking of the granules is avoided and at the same time the bulk density becomes small, so the yield of the furnace increases.

The heat transfer members having a high heat storage capacity, a high thermal conductivity and a large surface area are located close to the free surface of the furnace liner, so that the granules forming the furnace filling can cover the members in a certain amount.

Figure 2 shows a longitudinal section of a part of a furnace in which the heat transfer members are rods 32. The rods are anchored to support rings or support ring parts 33 · The rods 32 are relatively dense all around the inner surface of the furnace. The distance between them can be 1-5 times the diameter of the private rod. In Figure 3, the distances between the rods are approximately the same as the diameter of the private rod.

Figure * + shows a second support part which, together with the corresponding parts, is able to support two rod layers. The support part 3, like the support part 33, is provided with holes and these holes are located in two rows, namely in the row of holes 35 and in the row of holes 36. The rods are fitted immediately into the holes. The support part 3 * + runs through the liner and is fixed to the oven wall with a few shoulders 37 · The rods can be 10 - 20 mm in diameter and are preferably made of refractory steel. The rods shown in Figures 2, 3 and Π · have a circular cross section.

However, there is nothing to prevent the use of any other cross-section, e.g. rectangular as shown in Fig. 5 · In this case, the rods may be formed of flat strips 3 * + k - 3 ^ e, which are metal with high thermal conductivity, and outer layers 3 * + a and 3 ^ f can then be a metal with high mechanical strength. The rod thus obtains both high thermal conductivity and high wear resistance. The sides are also covered with a wear-resistant layer.

The rods 32 form an acute angle with the feed direction of the furnace. Such an arrangement of the rods can be achieved in such a way that the holes of the support ring part 33 on the left of Fig. 2 are displaced slightly in the clockwise direction relative to the holes of the support part 33 on the right of Fig. 2.

Claims (5)

5 56368 Claims A rotary kiln apparatus for producing an expanded clay product, comprising a slowly rotating drying oven (1) in which the temperature of the clay product is raised from ambient temperature to 300-600 ° C over a relatively long period of time and a fast rotating kiln (2) in which the clay material is fired at 1150-1175 ° C and the transition zone (A) between these furnaces, where the temperature of the clay product is brought from 300 to 600 ° C to between 1150 and 1175 ° C within 15 to 30 minutes, in addition to which the furnace equipment includes longitudinal rods (32), spaced apart from the furnace liner, characterized in that these rods (32) are arranged in the transition zone (A) and are formed so strong that they can act as heat transfer members with a high heat storage capacity, the rods being arranged in several, preferably two, layers (35). , 36) and forming an acute angle with the longitudinal axis of the furnace. Furnace installation according to Claim 1, characterized in that the cross-section of the heat-transfer rods is rectangular and is formed, for example, from flat strips (3 ^ a-f). Furnace installation according to Claim 1 or 2, characterized in that the heat-transfer rods, viewed in the longitudinal direction of the furnace, extend in said direction by a factor of 1 to 5 times the furnace. 1. Rotation of the product for the production of the product with a high temperature (1) color of the product with a temperature at the end of the temperature at a temperature of 300 to 600 ° C at a temperature of 300 to 600 ° C rotating product (2) color of the product at a temperature of 1150 to 1175 ° C, in addition to the product temperature of 300 to 600 ° C up to 1550 to 1175 ° C minuter, varförutom i ugnsan-läggningen ingär längsgäende stavar (32), som är p & visst Avstand frkn ugnsfodret, kännetecknad därav, att dessa stavar (32) är placerade i övergängszonen (A) ocää är kraftigt utformade, attme kan fungera som med stor värmekapacitet,