Method and apparatus for cleaning a rotary agitator in a reactor

An agitator mounted in a reactor is cleaned while being rotated by introducing an unconfined jet stream of pressurized liquid from a nozzle through an opening in the reactor wall into contact with the agitator and oscillating the nozzle so that the liquid jet oscillates in a plane passing substantially through the axis of the reactor.

The invention relates to a method and apparatus for cleaning a rotary 
agitator directed along the axis of a reactor and passing close to its 
wall, by means of a jet of pressurized liquid. 
Normal methods of cleaning reactors with a jet of pressurized liquid 
comprise inserting an injection nozzle into the reactor. In the case of a 
reactor equipped with a rotary agitator directed along its axis and 
passing close to its walls, such method does not enable the agitator to be 
cleaned while in movement. 
It is an object of this invention to provide a method and apparatus which 
overcomes this disadvantage and enables the reactor and agitator to be 
cleaned while the agitator is in operation.

In the course of its rotation, the agitator sweeps over one or more coaxial 
surfaces of revolution, depending upon its shape. 
In the method of this invention, the jet of pressurized liquid directed 
into the reactor comes from adjacent and beyond the external face of the 
surface of revolution over which the agitator sweeps during its rotation. 
The cross-section thereof, perpendicular to the axis of the reactor, is 
the maximum-diameter cross-section at every point along said axis, and the 
jet oscillates in a plane passing substantially through the axis of the 
reactor. 
The cleaning arrangement according to the invention is of the type 
comprising means for producing a jet of pressurized liquid, including an 
injection nozzle. It comprises means for oscillating the injection nozzle 
in a plane, preferably through an angle of 30 to 170 degrees for 
satisfactory operation. 
In another special embodiment of the cleaning arrangement, in accordance 
with the practice of this invention, the arrangement is mounted in a 
sealed relation within a neck portion extending from the reactor, such as 
neck 31. This makes it unnecessary for the arrangement to be withdrawn 
before the reactor is used. 
Referring now to the drawings, the cleaning arrangement comprises an 
injection nozzle 1 supported by a nozzle carrier 2. 
The nozzle carrier 2 is rigidly connected to a crank 3 which is pivotally 
connected by a joint at one end 4 of an elongate rod 5. A motor 6 drives 
the other end 7 of rod 5 in a rotary movement in a plane perpendicular to 
that of FIG. 1, as by means of a cam 8. A ring 9 holds cam 8 in position. 
A shaft 10 of cam 8 is connected to a drive shaft 11 by a coupling sleeve 
12. 
Nozzle carrier 2 oscillates about a hollow shaft 13 connected to a pipe 14 
through which the injection nozzle 1 is supplied with liquid from a 
suitable supply source. 
Nozzle carrier 2 has three components, namely, a central element 15 rigidly 
connected to injection nozzle 1 and sandwiched between two lateral 
elements 16 and 17 rigidly connected to the central element 15. An annular 
space 18, communicating with the inside of shaft 13, through an aperture 
19, and also communicating with injection nozzle 1, is provided between 
shaft 13 and central element 15. An annular space is made fluid-tight by 
seals 20 and 21. Rings 22 and 23 and ring 24, respectively hold the nozzle 
carrier 2 and shaft 13 in position. 
Shaft 13 is rigidly connected to a stirrup-piece 25 which in turn is 
rigidly connected to a U-shaped beam 26 which is rigidly joined to the 
underside of a supporting plate 27. The supporting plate 27 has an 
aperture 28 for passage of pipe 14 therethrough and an aperture 29 for the 
passage of rod 5 therethrough while the motor 6 is fixed to the top side 
of the plate 27. 
The cleaning arrangement is mounted on reactor 30 by fixing supporting 
plate 27 onto neck 31 extending from the reactor 30. The cleaning 
arrangement and neck 31 are designed so that the oscillating plane of the 
injection nozzle 1 passes through the axis 32 of the reactor 30 so that 
the outlet orifice of nozzle 1 is near but beyond the external face of the 
surface of revolution over which the agitator 34 sweeps during its 
rotation; the cross-section thereof, perpendicular to the axis of the 
reactor, is the maximum-diameter cross-section at every point along the 
axis. The agitator is rotated by conventional means 35. Reactor 30 may 
have more than one neck portion, each being designed to receive a cleaning 
arrangement according to the invention. When the cleaning process is over, 
the arrangements may be withdrawn and each neck sealed by an appropriate 
means, such as a cover. 
It will be understood that changes may be made in the details of 
construction, arrangement and operation, without departing from the spirit 
of the invention, especially as defined in the following claims.