Apparatus for the chemical conditioning of sludges

DETAILED DESCRIPTION We claim: 1.
An apparatus for the conditioning of sludges comprising: a.
first and second vertically arranged cylindrical vessels, each vessel having a sealed bottom and a sealed top; b.
an overflow pipe connecting the first and second cylindrical vessels installed tangentially to the upper portions of the first and second cylindrical vessels; c.
a sludge feed pipe connected to a source of sludge, said sludge feed pipe being installed in a direction tangentially opposite the overflow pipe above the bottom of the first vessel; d.
a feed tube connected to a source of a first conditioning material, said feed tube being installed tangentially into the sludge feed pipe; e.
two further feed tubes being respectively connected to sources of a second and a third treating material, said two further feed tubes being installed tangentially into the overflow pipe; and f.
a discharge pipe installed in a direction tangentially opposite the overflow pipe above the bottom of the second vessel, said apparatus being further constructed and arranged whereby the sludge entering the sludge feed pipe is mixed with the first conditioning material, spirals upward through the first vessel, passes through the overflow pipe wherein it is mixed with the second and third conditioning material, passes into the second vessel, spirals downward thereby further mixing the sludge and the conditioning materials and is discharged through the discharge pipe.
2.
The apparatus of claim 1 wherein the overflow pipe is provided with a detachable coupling.
3.
The apparatus of claim 1 wherein the capacity of the second vessel is larger than that of the first vessel.
4.
The apparatus of claim 4 wherein the three feed tubes can be equipped with inserts of different diameters.
5.
The apparatus of claim 1 wherein the ratio of internal height to internal diameter of the first and second cylindrical vessels is between 1.
4 and 2.
1 to 1.
6.
A process for the conditioning of sludge comprising: a.
feeding sludge to the lower part of a first vertically arranged cylindrical vessel having a sealed bottom and a sealed top; b