DE578980C - Tube mill for drying, grinding and, if necessary, burning goods - Google Patents

Description

ISSUED ON
June 19, 1933

BMriheek
Bur. Ind. Self-dom

19 JUL. 1933

For drying, grinding and also firing, if the latter is also required Good of all kinds are two different procedures known.

According to one known method, the individual work is carried out one after the other and carried out separately in different apparatuses.

The drawbacks of this procedure are:
i. high investment, operating and maintenance costs as a result of the many main and intermediate facilities;

2. poor drying efficiency with uneven size of the goods, because the Dry small pieces faster than large pieces, but dry up to Drying of the latter must be done, leaving the small pieces unnecessary be heated;

3. Somewhat greater heat consumption compared to the following known second method, in which the work is carried out together and at the same time, because the material must be dried more sharply, since it is not crushed in the hot state and so is not subject to strong re-evaporation, which would otherwise cause another Part of the moisture or the residual moisture is evaporated without additional heat supply.
The advantages of this procedure are:

1. Good grinding efficiency, because the material is dry or with a very low Moisture content and passed to grind cold;

2. Good burning efficiency, since the material is burned in a device specially designed for the purpose.

According to the second known method, the work is done together and always carried out simultaneously in one apparatus.

The disadvantages of this procedure are:

X. poor drying efficiency, especially with a higher moisture content of the material, since the drying is carried out in the device designed for grinding, the material being withdrawn from the heating gases by the grinding media and drying being severely hindered. If the moisture content of the goods is lower, this is compensated for, as the progressive splitting of the goods causes them to lose their moisture more easily;

2. poor grinding efficiency as a result of grinding the moist material, as the (.nit long between the grinding media filling strangled around before it is dry enough to be wedded. In particular with increasing moisture content of the feed material, the efficiency deteriorates very strong. In many cases, even relatively small ones fail Degrees of moisture the grinding completely, as a result of rapidly growing large Approach image on the mill wall

Grinding media run on the good without it chop it up so that it is completely removed from drying; ·

3. poor firing efficiency, since the firing is part of the process for grinding Device is carried out. The advantages of this procedure are:

1. Simplicity and cheapness of ^: facilities,

2. Heat savings due to large re-evaporation of moisture in the shredded hot material.

The invention now has the purpose of creating a new method of treatment which eliminates the disadvantages of the known methods and maintains their advantages. ■. According to the invention, this new treatment consists in the fact that the work in a device, for. As is known, are carried out in a tube mill, are provided in the completed in certain intervals of grinding media for the purpose of drying and firing by formed \ ^r orrichtun.gen.

So it will not be like the well-known mill drying and firing process permanently ground and at the same time permanently dried and possibly burned, but it is, indeed, also permanently dried and possibly burned, but the MaIi-Jen does not happen continuously, but only with an interruption, whereby during the interruption the drying and, if necessary, the firing is carried out in special devices. This increases the efficiency drying and firing increased significantly, since these work without any Disability go on, and further is achieved by the faster drying of the Good, the grinding efficiency is essentially raised, which is also because the damp Well in the repeated by interruption limited heels is not strangled between the grinding media for as long as with the known method, is much cheaper.

By intermittently alternating the increased heating with the grinding thus ensures that the work in the individual paragraphs with the best possible ^ efficiency must be carried out and also the previous work always a very significant improvement "in the efficiency of the subsequent work in the wake has, so that the individual efficiencies and thus the overall efficiency of the new process significantly above the known Procedure lies.

The individual drying sections

as well as the sections of milling and heating can be carried out using large ■ ßi'ii λ case Ikth ·]> e rn also partly inside the "grinding media" can be accommodated in order to reduce the batt length of the mill ".

The drying and heating of the goods can be wholly or partly directly or happen indirectly. So z. B. with very sensitive goods that do not contaminate may be carried out both work indirectly. Since the. Indirectly working ver .'_ do not drive as economically, is like that un- 7 " indirectly 'working, - one avoids it, if there is any good. permitted, and performs drying as well as "heating in an immediate manner." "". "" -.

In cases where e.g. B. the firing temperatures are relatively tightly limited. d. H. in which every excess of temperature makes a deterioration, if not a disuse of the items to be fired, drying can take place immediately and the Burning can be carried out indirectly. In this way you can use the good efficiency of the. immediate way of working at the Drying out and increased, 'because with the! indirectly operating process temperature fluctuations as well as harmful higher temperature fluctuations not so quickly This affects the operational reliability of the combustion process.

The drying and, if necessary, the burning of the goods can be carried out in the. .DC.or. take place in countercurrent.

To further increase profitability Depending on the type of processing, it is advisable to use the Remove any vapors that occur during drying, as separately as possible from the classifying air. Under other things can thereby, the temperatures lower content in the discharge due to the lower moisture content of the heating gases without fear of excretion of water.

If the vapors are discharged in a special way, heating or burning must of course take place - separate heat can be supplied again. But even if the vapors are not discharged separately, it is a logical support for the batch-wise operation expedient to supply heat separately for burning, especially if- 'ό the firing takes place wholly or partially after the fine grinding, so as not to. "useless impaired by high degrees of warmth. Should be due to the low exhaust gas temperature there is a risk of precipitation or other excretions in the discharge, so, of course, heat is also added separately in the discharge, to avoid precipitation.

On the drawing, an embodiment of the E rfiiiduiigsgegenstand is shown, in the picture is a tube mill im

Section drawn, and the course of the grist is indicated by an arrow Marked by a dash-dotted line.

The process is as follows:
The material is given up by the feeder α of the mill and reaches the mill section f _1; which is provided with through-trained devices for drying, in which the good initially mainly the

ίο loses surface moisture.

The heating gases are introduced into the mill by the blower e using a pipe provided with an air distributor / at the end and in this case blown through the whole mill, at the same time taking over the heating iind the sifting.

The arrangement of a mill section provided with drying devices at the beginning the mill enables the processing of goods with a very high moisture content.

The execution of the devices in the

Mill sections. which are used for drying or for heating and burning the goods can be different. Thus, in a known manner, shovel, cell, trickle, pipe, electrical or such built-in components can be provided which are intended to form a layer of material for sucking the heating gases through or forcing them through the material. According to the device, the heating means is air, gas, steam. Water or electricity. In the figure, in section ^ _1, shovel fittings are provided and chains are used for stowage for the heating gases and the goods. In the case of sticky feed material, the chains are hung up in such a way that they constantly rub against each other and against the mill wall in order to free themselves and the mill wall from caking and to clean them.

X'ach \ ^r adopted in the drying section enters the f _t on dried material in the mill section t _2, which is equipped with devices for coarse crushing. which in this kale carried out a large-scale grinding element working with sieving.

The drying of the goods continues in this section as the heating gases pass through pull it through, but with a much lower degree of efficiency, since the good is largely withdrawn from the attack of the hot gases by the grinding media. Is the task size large or very unequal, so are used in the first for the comminution certain section useful as a grinding straw Grids provided on which the grinding media run, in order to achieve a possible the same piece size, which is useful for even further drying, as well to carry out an economically bc

fio gradually knew)! Crushing.

From the section /., The comminuted material comes into the drying section t ₃ , which is again provided with special devices for heating.

The drying of the material after the pre-shredding is quicker and easier, so that the efficiency of the drying is also improved.

The installation for heating the goods is shown again as a shovel installation with chains as well as with a further installation, which is used as a heat store and thus as a special, indirect drying and heating agent is used.

The material then passes into the mill sections t _A and i ₅ , which are again provided with summer devices for comminution. In section i ₄ , a roller grinding body provided with a sieve works for coarser grinding, while fine grinding in section έ _{Ά is carried out} in parallel grinding chambers with small grinding bodies. The heating of the material continues in this double section formed by the diversity of the grinding media, of course again with the efficiency limited by the grinding media.

In section t ₆ , the last unimpeded heating of the material, again carried out with the best efficiency, takes place in a special device, if necessary, up to the firing temperature.

The arrangement of a mill section which is only used for unhindered heating or burning at the end of the mill also had the advantage, that also the efficiency the grinding is still raised, since the greatest warming of the goods, which yes in particular the fine grinding is impaired and the wear of the grinding media increases, sometimes only after the fine grinding.

Hub and Streuscluutfelii are drawn as internals in this heating device for the good; furthermore are again for the Back-up of the heating gases and the goods chains, plates and rings provided, in particular the latter also serve as heat storage.

These heat accumulators are particularly useful when the mill is shut down, and in fact when if well processed in the mill, which hardens quickly when it cools down • and cakes, because they then hold back these processes as a result of their further heat emission, so there.? not everyone's mill Standstill 'needs to be driven empty.

If the goods tend to stick, as in the built-in components, the drying sections The chains are also hung on one side or loosely to avoid the caking to tear away and as a cleaning and

to serve stirring means. In very difficult ones In some cases, an inevitably driven agitator or the like can be provided.

After leaving the mill section f 1, the material arrives in the mill section f ₇ , which serves as a classifying space and which is provided with deflection devices for the dust-containing gases for the purpose of separating out oversized grain.

The number and extent of the individual sections is from. the nature of the respective goods, the behavior of the goods during processing and the desired End result dependent.

To avoid heat loss, the mill is completely or partially covered with heat protection agents isolated.

Claims (2)

Patent claims: 1. Tube mills for drying, grinding and possibly burning of goods, thereby characterized in that in the tube mill housing heated over its entire length alternately for heating and devices designed for grinding the material are arranged. 2. Mill according to claim i, characterized in that that the drying devices are located inside roller grinders. · 1 sheet of drawings BEIrLlS *. GEDRl ¹ CKT IN DKI!