Means for conveying a mixture of products having different density

A transport pipe for a compressed-air conveying of a homogeneous mixture, the pipe including a nozzle on the outlet end of the pipe for discharge of the mixture into a storage container. The nozzle comprises a throughflow opening for passage of the mixture therethrough, and lateral openings for the discharge of compressed air into a mixture-confining sheath of compressed air about the mixture.

BACKGROUND OF THE INVENTION 
The present invention relates to a means for conveying a mixture of 
products having different density from one place to another via a 
transport pipe and with the help of compressed air. The mixture may 
contain particles of different sizes. It is desirable for the mixture to 
be as homogenous as possible and not divided into layers of different 
sizes. An example of such a mixture is fodder mixtures which may contain 
both largish particles and particles in the form of powdered grains. In 
the case of fodder it is important for the mixture to be as homogenous as 
possible since it is to be used for feeding animals and it is important 
for the animals to receive a correctly balanced mixture on which to feed. 
A fodder mix may be fully homogenous at the delivery point, transferred to 
a tank vehicle and then transported to a consumer who generally has a 
silo. The mixture is transferred to the silo from the tank via a transport 
pipe using compressed air. When the fodder mix is emptied into the silo, 
the homogeneity is generally lost, which is a disadvantage to the 
consumer. To prevent this happening the use of a cyclone has been 
suggested at the top of the silo to maintain the homogeneity. However, the 
cyclone has the drawback that its walls are worn relatively quickly by 
passing fodder. 
SUMMARY OF THE INVENTION 
The object of the present invention is to achieve retained homogeneity in 
the fodder mix when it is emptied into the silo, without the use of a 
cyclone. This is achieved by allowing the fodder mix to pass through a 
nozzle at the top of the silo, the nozzle being designed so that a sheath 
of compressed air is formed around the fodder mix flowing through the 
nozzle. The existence of this sheath ensures that the fodder mix being 
emptied into the silo retains its homogeneity. 
Should it be necessary to transfer a homogenous fodder mix from a tank 
vehicle to an arbitrary storage place with retained homogeneity it is 
quite sufficient to use a casing of solid material which is closed at one 
end and is provided at this end with a nozzle of the type described so 
that a sheath of compressed air is obtained inside the casing while the 
fodder mix is being emptied. 
When transferring the fodder mix from a tank vehicle to a silo it is 
advisable to work with an air pressure up to about 1 kg/cm.sup.2. 
The density of the various particles in the fodder mix varies between 450 
and 850 kg/m.sup.3. 
A suitable transport volume per time unit when transferring a fodder mix 
from a tank vehicle to a silo is 1000 m.sup.3 /hour. 
When transferring fodder mix approximately 10% of the volume should be 
fodder and 90% compressed air. If the mixture consists mainly of flour 40% 
of the volume should be mix and 60% compressed air. 
Additional features of the present invention are revealed in the following 
detailed description.

DETAILED DESCRIPTION OF THE INVENTION 
The FIGURE shows a transport pipe 1 for transferring homogenous fodder mix 
from a tank vehicle with the help of compressed air having a pressure up 
to 1 kg/cm.sup.2. The transport pipe opens into a nozzle 2, this being in 
the form of a housing comprising a cylindrical wall section 22 and a 
conical wall section 3. At the bottom 4 of the cylindrical section 22 are 
four ridgelike parts 5-8 arranged in such a manner as to form a cross. 
Throughflow openings 9 and 10 are arranged between two adjacent parts. The 
conical section 3 is provided with a number of openings 11 for compressed 
air. The nozzle 2 is located inside a silo 12 having a conically closed 
upper part 13, a cylindrical part 14 and a conical bottom part 15 with an 
outlet 16. The silo 12 stands on four legs 17-20. 
The means described above functions as follows: It is assumed that the 
transport pipe 1 is connected in some way to a tank vehicle delivering a 
homogenous fodder mix with the help of compressed air, the volume being 
transferred from the tank comprising 10% fodder and 90% compressed air. 
When the volume being transferred reaches the nozzle 2, the fodder runs 
vertically straight down and is distributed by the ridge-like parts 5-8 so 
that the fodder leaves the nozzle 2 through the openings located on each 
side of the ridges. The compressed air flows out through the openings 11 
and forms a sheath or casing located inside the conical part 13 and the 
cylindrical part 14 so that the fodder mix 21 leaving the nozzle 2 is 
completely screened from the conical part 13 and the cylindrical part 14. 
The existence of this air curtain between the fodder mix 21 and the parts 
13 and 14 provides the advantage that the fodder mix 21 retains its 
homogeneity. 
It is no doubt clear that the present invention is not only applicable to 
silos. It may also be necessary to transfer a homogenous fodder mix to a 
storage place of some other type with retained homogeneity. This is 
possible with a means reminiscent of that shown in the drawing but 
deviating therefrom in that the bottom 15 and legs 17-20 have been 
removed. This results in a means consisting of a nozzle according to the 
invention, which is surrounded by a sheath or casing of solid material and 
which, upon emptying, creates a curtain or sheath of gaseous material 
inside the casing of solid material.