SE428274B - PROCEDURE FOR MIXING CEMENT, WATER AND BALLAST - Google Patents

Description

80026214 »10 15 20 25 30 35 40 without being worn down unacceptably fast, cement, water and aggregate are mixed in a special way in a special device 9. This has a premix assembly 10 consisting of a premix vessel 11, with a rotatably mounted stirrer 12. , which is driven by an electric motor 13 via a V-belt transmission 14. At the top of the premix vessel 11 a dry cement line 15 and a water line 16 open, while the premix vessel 11 at the bottom has a discharge line 17 for discharging cement slurry obtained by mixing cement and water by means of stirrer 12.

The cement slurry discharge line 17 opens at the same location as a ballast supply line 18 into an intermediate mixer 19 consisting of a mixing vessel 20 and a rotatably arranged mixing means 21, which is driven by an electric motor 22. The intermediate mixer 19 is intended to mix the cement slurry with ballast before these materials reach the mixing vessel 1 via the supply line 23.

The device 9 can furthermore have a line 24 for separate feeding of coarse ballast, i.e. stone material directly to the mixing vessel 1 without the stone material having to pass the intermediate mixer 19 together with the sand material of the ballast. Furthermore, the device 9 can have a throttling device 25, which allows one to close and open the cement slurry line 17 and in addition can regulate the flow area of this line 17.

The device 9 is intended to allow premixing in that cement and water are mixed in the premix assembly 10 to cement slurry, which is fed to the intermediate mixer 19, in which the cement slurry is mixed with the ballast (or at least the sand material in the ballast), after which the cement slurry / ballast mixture is fed mixing vessel 1 where the vanes 3 and 4 can carry out the final mixing operation itself. As a result of this process, the pulp has already obtained such a consistency and the components of the pulp are so distributed that the blades 3 and 4 can be driven at high speed without the incoming pulp subjecting the blades 3 and 4 to unrealistically high wear as is the case if they forced to move at high speed in more or less dry cement-aggregate material and / or in dry-cement and then dry aggregate or vice versa before the water has had time to distribute in these materials. As a result, the mixing vessel 1 and its stirring plant 2 can be completely focused on an intensive final mixing of premixed material, whereby a concrete material with favorable bonding ability and / or a high-quality concrete material can only be obtained. by increasing the agitation unit's 2 agitation speed, ie without, for example, having to increase the cement content.

To save time, premixing of cement and water in the premix assembly 10 to cement slurry can take place while a premixed mass present in the mixing vessel 1 is ready to be mixed by means of the agitator 2. When the final mixture in the mixing vessel 1 is finished, this is emptied in a conventional manner. then immediately fed to the mixing vessel 1 together with the ballast.

In some cases it may be advantageous to use such a large premixing vessel 11 that it holds a plurality of batches of cement slurry, each of which can be mixed with a batch of aggregate.

The cement slurry / ballast mixture can be added to the mixing vessel for a prolonged period of time, whereby the vanes 3 and 4 can distribute premixed material portions as they reach the mixing vessel 1.

The shut-off / throttling device 25 allows cement slurry to be mixed with the ballast in an accurate and controlled manner with or without a special mixing means 21.

It can often be advantageous to transport the premixed mass to the mixing vessel 1 without it falling any further distance. To enable this, the line 23 can extend all the way to the mixing vessel 1 and be connected to it.

Coarser parts of the ballast such as its stone material can be fed directly to the mixing vessel 1 via the line 24, which means that the stones are transported past the intermediate mixer 19, whereby this and its possibly moving parts are spared.

The coarser ballast parts, i.e. the stones in the ballast, can preferably be transported to the mixing vessel 1 when the associated mass has already been added and mixed in it. In this way, the paddle speed can be kept very high for intensive mixing of incoming cement slurry / ballast sand and when this intensive mixing is carried out, the paddle speed can be reduced, after which the ballast stones can be added for more careful ready-mixing, which is gentle in all respects.

The procedure described above can of course be performed with

Claims (8)

Devices other than the one illustrated in the drawing and the method may vary within the scope of the appended claims. PATENT REQUIREMENTS A process for mixing cement, water and aggregate in a mixing vessel (1) for the production of concrete material, in which cement and water are premixed into a cement-water mixture, known as premixing the cement / aqueous mixture with the aggregate during the supply to the mixing vessel (1) by means of a mixing device (19), which is active in the area where the cement / water mixture reaches the ballast stream. Method according to claim 1, characterized in that cement and water are mixed into a cement / water mixture while the cement / water / ballast material existing in the mixing vessel (1) is ready-mixed. 3. A method according to claim 1 or 2, characterized in that cement and water are premixed into a cement / water mixture for a plurality of batches of aggregate. Method according to one of the preceding claims, characterized in that the cement / water mixture and the ballast after the premix are fed into the mixing vessel (1) for a prolonged period of time, wherein stirring means (3, 4) in the mixing vessel (1) affect the incoming the material flow as it reaches the mixing vessel. ' 5. A method according to any one of the preceding claims, characterized in that cement and water are mixed to obtain such a consistency that the mixture can be metered into the ballast stream in a controllable manner, for example via an adjustable throttling device (25). Method according to one of the preceding claims, characterized in that the cement / water / ballast stream is supplied to the mixing vessel (1) via a transport device (17, 18, 23) which transports the stream into the mixing vessel (1) from above and delivers the stream first. when it has reached the mixing vessel (1). Method according to one of the preceding claims, characterized in that coarser parts of the ballast are fed into the mixing vessel (1) independently of other ballast material. Method according to claim 7, characterized in that the coarser parts of the ballast are added to the mixing vessel (1) at a time when a certain mixing of other material has taken place in the mixing vessel (1). The present invention relates to a process for mixing cement, water and aggregate in a mixing vessel (1) for the production of concrete material, in which cement and water are premixed into a cement / water mixture. In order to allow mixing of the mass in the mixing vessel to the desired extent so that the finished concrete material meets the set requirements in terms of bonding ability and without requiring undesirably large cement consumption for the production of concrete material of a certain quality, the method according to the invention / the water mixture is premixed with the ballast during the supply to the mixing vessel (1) by means of a mixing device (19), which is active in the area where the cement / water mixture reaches the ballast stream.