HU198645B - Apparatus and method for forming contact substances - Google Patents

Abstract

The aim of the invention is to produce catalyst moldings whose properties, such as strength and porosity, are as constant as possible. The object is to develop a device and a method for the deformation of catalyst masses by means of extruder screw with attached double-shaft mixer, whereby the consistency of the masses used as little as possible changed. This object is achieved by a device in which the mixing vanes of the twin-shaft mixer have a round cross-section with a diameter of 0.1 to 0.4 of the screw diameter and arranged at the bottom of the double-shaft mixer screw with 0.2 to 0.5 of its diameter in the The mixer room protrudes. This object is further achieved by a method in which the direction of rotation of the mixing vanes for highly plastic, lumpy masses from the top to the inside, for less plastic, kruemelige masses directed from the top to the outside. The invention is used for the deformation of catalyst masses.

Description

The present invention relates to an apparatus and a method for forming catalyst materials using a screw extruder, wherein the catalyst materials are formed into a ribbon body which can then be further processed into a catalyst, catalyst support or adsorbent.

Patent No. 141,904 in the GDR and U.S. Patent No. 1,269,596. It is known from the disclosure document of the Federal Republic of Germany that ceramic and catalyst materials can be shaped into a ribbon-shaped body by means of a screw press.

The auger is fed through a single or biaxial mixer or kneader with a screw or Z-shaped mixing paddle or kneading paddle. Such a solution is described in German Patent Nos. 1,120,344 and 98,455. The mixing / kneading paddle generally has a rectangular, trapezoidal or triangular cross-section, see, for example, German Patent Publication No. 2942325.

A disadvantage of the known technical solutions is that the consistency of the molding material during the feeding into the worm changes due to the kneading effect. The properties of the products thus obtained vary widely.

Particularly disadvantageous are the differences in the quality parameters of the catalysts and adsorbents, such as the porosity, pore structure and strength of the finished products. The varying consistency of the pulp requires continuous readjustment of the cutting frequency and / or auger speed to maintain the desired product length.

It is an object of the present invention to provide an apparatus and method for shaping catalyst materials into a ribbon-like body which provides products of the same quality characteristics (strength, porosity and pore structure).

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus and method for forming catalyst materials using a two-axis agitator screw extruder, wherein the consistency of the materials used is substantially constant when uniformly added to the auger.

In order to solve this problem, an apparatus is provided which has a worm belt press equipped with a biaxial mixer, wherein according to the invention, the blade of the biaxial mixer has a cross-section of 0.1-0.4 times the diameter of the screw. , Extends 2 to 0.5 times into the mixing chamber. The best effect is obtained in an embodiment where the diameter of the circular cross-section of the agitator blade is 0.3 times the diameter of the auger.

In order to solve this problem, a method has been developed in which, depending on the consistency of the mass to be formed, the mixing vane is rotated from top to bottom in the case of highly plastic, lumpy masses, rotated from the top to the mixer, Keep it at -5. Particularly advantageous and constant quality can be achieved if the level of the mass in the mixer is maintained at 3 times the rotating diameter of the mixing blade.

The invention will now be described in more detail by way of examples.

Example 1

A worm belt press with a biaxial mixer was used, with a screw having a diameter of 160 mm, a cross-sectional blade according to the invention having a diameter of 50 mm and a rotary diameter of the blade of 360 mm. By means of the belt press formed in this way, the wet crumbled aluminum hydroxide mass was formed into strips (bars) of 1.8 mm diameter and cut into 6 mm lengths, which are suitable for further processing into a catalyst support. During this the filling level of the mixer was kept between 50 and 70 cm. The direction of rotation of the agitator blade was adjusted from top to bottom.

During the processing of a 30C kg batch, 10 samples of the formed bands were taken and subjected to drying and annealing under specified conditions. Following this, 10 strips per sample were tested, i.e. pore volume (Vp) and strength as diametric rupture pressure (BD). The mean of the results is shown in Table 1.

Example 2 (Comparison)

The same mass as in Example 1 was fed into a worm belt press, which is preceded by a two-axis kneading machine, where the kneading machine is provided with a trapezoidal Z-shaped kneading blade. During the processing of a batch of 300 kg, 10 samples were taken from the formed webs, which were dried and annealed under the same conditions as in Example 1 and subsequently examined. The results are shown in Table 2.

Comparing the results obtained with Examples 1 and 2 (Table 1 and Table 2), it can be concluded that the difference in quality characteristics of the formed products is reduced when using the apparatus and method according to the invention. Table 2 shows to3

EN 198645 Β furthermore, in contrast to Table 1, there is an increasing tendency for fracture pressure (fracture force) and a decrease in pore volume for the formation of the catalyst material used, 5

Example 3

Pseudoboehmite and kaolin were vigorously mixed at a ratio of 2: 1 by weight and plasticized with nitric acid and distilled water. The resulting mass was highly plastic and lumpy. Subsequently, molding, drying and testing of the tapes were performed in the same manner as in Example 1. The results are shown in Table 3.

Example 4

The mass of the pseudoboehmitacoline of Example 3 was shaped into strips in the screw press of Example 1 by rotating the mixing paddle of the biaxial mixer from above to the inside. The strips were dried and tested as in Example 1. The results are shown in Table 4.

Example 5 (Comparison)

The highly plastic and lumpy pseudoboehmitacoline masses of Examples 3 and 4 were converted into ribbons (bars) in a 35-screw belt press using a two-axis kneading machine with the Z-kneading paddle of Example 2. The strips (bars) were dried and tested according to the previous examples. The results are

They are listed in Table 5.

Table 1 45

Sample number burst index force (N / product) pore volume (cm ³ / g) 1 157 0.97 2 163 0.94 3 138 0.95 4 146 0.99 5 155 1.01 6 141 0.94 7 162 0.98 8 137 0.93 9 143 0.91 10 159 0.99

Table 2

Sample number burst index force (N / product) pore volume (cm ³ / g) 1 92 0.91 2 87 0.89 3 117 0.95 4 102 0.87 5 113 0.83 6 148 0.79 7 141 0.81 8 133 0.77 9 161 0.71 10 157 0.76

Sample number Table 3 burst index force (N / product) pore volume (cm ³ / g) 1 128 0.49 2 120 0.52 3 135 0.48 4 144 0.46 5 124 0.50 6 150 0.44 7 140 0.47 8 138 0.48 9 125 0.50 10 144 0.46 -.

Sample number Table 4 burst index force (N / product) pore volume (cm ³ / g) 1 125 0.51 2 125 0.53 3 135 0.49 4 139 0.48 5 133 0.50 6 124 0.54 7 130 0.52 8 131 0.50 9 130 0.51 10 129 0.52

HU 198645 Β

Table 5

Sample number burst index force (N / product) pore volume (cm ³ / g) 1 140 0.47 2 150 0.48 3 123 0.50 4 142 0.43 5 130 0.44 6 148 0.42 7 140 0.43 8 151 0.41 9 155 0.39 10 160 0.40

Comparison of the results shows that by using the apparatus and the method according to the invention, products with constant quality characteristics can be obtained. In contrast, Tables 2 and 5 show a decreasing trend in pore volume and an increasing trend in fracture strength in the formulation of the catalyst materials used, which indicates poor quality characteristics.

Claims (4)

PATENT CLAIMS Apparatus for forming catalyst materials by means of a worm belt press equipped with a two-axis mixer, characterized in that its agitator blade is of circular cross-section having a diameter of 0.1 to 0.4 times that of the screw at the bottom of the biaxial mixer. extends to the mixing chamber by a factor of about one. Device according to Claim 1, characterized in that the diameter of the agitator blade is preferably 0.3 times the diameter of the screw. 3. A process for forming catalyst materials using a spiral belt press equipped with a biaxial agitator, wherein the agitator blades are rotated from the top to the top in the case of highly plastic, lumpy materials, and the filling level of the material in the mixer from the top to the outside. The rotor blades are held at a rotation diameter of 1-5 to 2 times. The method of claim 3, wherein the filling level of the material in the mixer is maintained at 1.5 to 3 times the rotating diameter of the mixing paddle.