Agitating – Mortar mixer type – Movable stirrer
Patent
1985-01-16
1987-01-20
Jenkins, Robert W.
Agitating
Mortar mixer type
Movable stirrer
366320, B28C 508
Patent
active
046377310
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for making of porous concrete intended for casting purposes, e.g., for casting portions of buildings such as foundation plates, walls and beams wherein principally cement, water and a frothing agent are simultaneously mixed in a way that air pores are produced in the mixture.
2. The Prior Art
A known method for making porous concrete involves mixing cement, sand, and water in a concrete mixer, after which a separately produced froth is lead into and mixed in the concrete. The concrete mixer constituted by a stationary tank having a rotating mixing screw or similar element therein. The froth is produced by a device in which a frothing agent is mixed with air and eventually water so that a froth with small air bubbles is obtained. A device for producing such a froth is described in the Swedish Patent Publication No. 156215.
In order to obtain a uniform quality of the cast porous concrete, i.e., such that it has a uniform density and strength, it is required that the included raw material be mixed in the right proportions. With continuous production, this has been found to be difficult as careful measurement of the flows of raw material and a watching of the mixing times. Further, an effective mixing of the air is required in order not to overly extend the mixing time.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a device for making porous concrete which is easier to use than known devices and which ensures that a uniform and high quality of the cast porous concrete is achieved. According to the invention the device enables all raw material to be mixed in batches, which means that the raw material can be added in exact quantities. Further, it includes control equipment in the form of a micro-computer by which the mixing time and other mixing parameters can be kept equal for all batches during one and the same casting. The device consists of a cylindrical mixing tank in which an impeller is arranged so that its axis of rotation coincides with the centre axis of the tank, and wherein the impeller includes blades that extend helicoidally along the inner envelope surface of the tank, by which the helicoidallity of each blade is less than 90.degree., preferably 40.degree., over the length of the tank and by which the blades extend a bit against the centre axis of the impeller.
Each blade preferably consists of two, in direction to the centre axis of the impeller, reciprocally parallel, flat strips which incline against the envelope of the mixing tank, so that the front edge of the moving direction of the outer strip is located next to the envelope. Between the strips, wings are arranged, by which respective wing is located in a plane which inclines against the centre axis of the impeller. Further, propeller blades preferably are arranged along the centre axis, which extend a bit from the centre axis. The blades preferably are supported by arms, which extend from the centre axis of the impeller and which carry a propeller blade each.
A great advantage with the device in accordance with the present invention is that all raw material can be prepared in one and the same apparatus. As such, there is no need for a special device for producing of froth, instead it is prepared at the same time as the porous concrete. This circumstance also has raised other demands on the design of the device compared with the known devices for making of porous concrete by putting in a prefabricated froth into concrete mixer.
Surprising it has been proved that the characteristics of the invention are deciding in order to carry out the preparation in the one and the same device and obtain an uniform quality of porous concrete besides the advantages that are reached by the batch-wise preparation which is described above. The turbulence which is obtained in the mixture by the blades of the impeller and propeller blades provides a good mixing of the air which is in the tank to provide a porous concrete with uniforml
REFERENCES:
patent: 701465 (1902-06-01), Cavin
patent: 2509543 (1950-05-01), Truax
patent: 2587127 (1952-02-01), Erickson
patent: 2633340 (1953-03-01), Zagray
patent: 2989291 (1961-06-01), Bepner
patent: 4448536 (1984-05-01), Strong
Cellexfabrikerna AB
Jenkins Robert W.
LandOfFree
Device for making porous concrete does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for making porous concrete, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for making porous concrete will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2132534