DE624881C - Method and device for sieving milk of lime u. like - Google Patents

Description

With milk lime vibrators such as those used in the sugar industry, Up to now one has had the difficulty that the milk of lime on the sieve is due to the access the carbon dioxide from the air could bind, so that the sieves clogged.

Attempts have already been made in various ways to counter this evil. For example, efforts have been made to prevent air access to the sieve as far as possible make it difficult or even prevent it completely, for example by putting on a sheet metal hood on the shaking sieve, which protrudes all around into the milk of lime and so an airtight Forms a water seal, or by wetting the sieve with steam or hot water nozzles, to keep the carbon dioxide off. These facilities were relatively cumbersome and, moreover, did not carry along real security to success.

According to the invention, the screen surface is arranged of the milk of lime vibrator within the milk of lime. This will make every entry of carbonic acid from the air to the sieve surface in a reliable manner, so that the harmful setting of the lime cannot occur.

There are already combined washing and screening devices for ore processing which the sieve works under water. One by chemical connection of the material to be screened Clogging of sieve holes caused by constituents of the air does not occur with ores in question, so the problem of the present invention is not at all for ores before.

The sieve surface working in the milk of lime is expediently inclined. In contrast to sieve devices known for use in other fields, in which the sieve surface is under water, according to the invention the vibrator moves on a circular path, see above ^; that the lime grit remaining on the sieve surface can be transported upwards on the inclined sieve path.

The new arrangement has the major advantage that very fine tissue for the Sieves can be used to remove most of the semolina from the milk of lime out, which will reduce the sugar mills sludge build-up. The device works continuously, and there is no need to stop for the purpose of removing large, sieved parts. .

One end of the inclined sieve surface protrudes over the edge of the lime milk container out. The screen coarse transported upwards through a suitable selection of the screen movement, in this case the so-called Semolina, is carried over the edge of the milk of lime container and can be poured into caught in a container below or carried away by other transport devices will.

According to the invention, the edge of the sieve

frame so high that it is inside the milk of lime jar All around protrudes from the milk of lime so that 3 "is above the sieve surface inflowing milk of lime can only get through the sieve bottom into the lime skimmer can.

The liquid level is raised by an overflow or other suitable device kept constant in the milk of lime flask, ίο As the sieve mesh. according to the invention moves on a circle or a similar self-contained path, its plane is perpendicular to the surface of the sieve, the liquid in which the sieve is immersed must be in At rest, flow evenly back and forth through the circling sieve mesh. Granted the liquid is given a certain inherent speed by regulating the amount of feed and discharge, so the liquid flowing back and forth through the sieve is no longer uniform. The flowing back is less when the sieve moves in the direction of the liquid movement, there Here is the flow rate as the difference between the sieve speed and the Represents fluid velocity. The flow rate is greatest through the sieve, when the fabric runs against the flow of liquid, look here both speeds: add. The milk of lime does not only flow in one direction through the sieve, but it is forced once for each circular movement of the sieve to flow back more or less strongly through the sieve. This backflow is used to briefly lift off the gravel layer that has formed on the sieve, whereby the removal of the semolina is made much easier. Also be Greens that want to get caught in the mesh are washed out again by the backflow of the liquid.

The invention is explained in more detail with reference to the accompanying drawings. Fig. Ι shows a lime milk vessel with vibrator in a Schetnati sher side view;

Fig. 2 shows a schematic front view.

In Fig. Ι a milk of lime vibrator is shown in two different positions .des vibrator. In the milk of lime container 1 there is milk of lime. The liquid level is indicated by line 2. The vibrator screen 3 is suspended in the drive shaft 4 encompassing springs 5 like bearings. The inclination of the sieve surface is adjustable. The adjustment device for the inclination of the screen surface is expediently set up in such a way that the suspension springs 5 enclose the shaft 4 like bearings and have a releasable clamping device which allows any screen inclination to be adjusted. A and B indicate different positions for the sieve surface. In position A , the milk of lime is added at arrow 6; the semolina expires at 7, the milk of lime at 8.

In position B the milk of lime is added at arrow 9. The semolina leaves the sieve at 10; the milk of lime runs off at. In order to create a constant liquid level for the immersion of the sieve, a partition wall 12 is arranged as an overflow weir. The frames 13 of the sieve protrude all around from the milk of lime.

Position B shows a mode of operation of the vibrator within the liquid, in which the screen coarse is conveyed upwards by a suitable vibration movement.

The drain nozzles that are not required are closed by valves that are not shown conclude.

In addition to the sieving of milk of lime, the device according to the invention can be advantageous can be used wherever screening processes take place where the material to be screened is below the Exposure to air or other reasons, bakes or similar Undergoes changes, for example in dry cutting.

Claims (6)

Patent claims: 1. Procedure for sieving milk of lime and other substances where the Admission of air makes the screening difficult, characterized in that the screening takes place by means of a vibrator within the liquid to prevent clogging of the Avoid sieve surfaces from caking of the material to be sieved - 2. The method according to claim 1, characterized in that by an inclined arrangement of the vibrating sieve surfaces and circular vibration movements Screen coarse is transported upwards. 3. The method according to claim 1 and 2, characterized in that by the Regulation of the inflow quantity, the oscillation amplitude and the number of oscillations of the vibrator which occur with each oscillation The size of the return flow through the sieve is influenced. 4. Sieve device for performing the method according to claim 1 with. Sieve surface arranged below the liquid level, characterized in that when the sieve surface is inclined, the edge of the Siebrahmens is so high that it comes out all around inside the lime milk container the milk of lime protrudes, and that through an overflow or other suitable Devices the liquid level in the milk of lime container is kept constant. S device according to claims 3 and 4, characterized by adjusting devices for the degree of inclination of the sieve surface. 6. Apparatus according to claim 5, characterized in that the suspension springs for the vibrator sieve include the drive shaft like a bearing and have a releasable clamping device by means of which the sieve inclination can be adjusted. 1 sheet of drawings