Device for the surface cleaning of rotating machine elements

Device for the surface cleaning of rotating machine elements such as the rotors of regenerative heat exchangers. A swinging cleaning arm is driven by an adjustable operating member to move across a rotor face through various angles, the extreme radially outer position of the cleaning arm being substantially constant, while its extreme inside positions, in various portions of its operating cycle, are variable. The operating member may be a fluid pressure motor; a control gear for the operating member contains a number of distribution sections arranged parallel in a distributing member. The distributing member is connected through connecting piping to a source of pressure fluid, and through further interconnecting piping is connected to the respective pressure spaces of respective operating members for swinging cleaning arms. The distributing member is controlled by an electric controlling member having a number of controlling sections, each controlling section having time switching elements, step-by-step selectors, and auxiliary electric controllers which may be adjusted to vary the parameters of the cleaning cycle of the cleaning arm, as required by the operating conditions of the apparatus being cleaned.

This invention relates to a device for the surface cleaning of rotating 
machine elements by a cleaning medium supplied to at least one cleaning 
nozzle arranged on a swinging cleaning arm. The device is of particular 
advantage in the cleaning of the heat exchanging surface and a rotating 
part of a regenerative heat exchanger. 
The heat exchange surfaces of rotors of regenerative heaters during 
operation become fouled with ash material contained in the combustion 
products passing therethrough. The fouling of the heat exchange surfaces 
is the cause of an undesirable increase of gas pressure loss, of 
decreasing efficiency, and results in conditions which may possibly give 
rise to a fire. Therefore the heat exchange surfaces must eventually be 
cleaned. 
In previously used cleaning apparatus there has been employed a swinging 
blower having a swinging blower arm with a water supply tube, with a steam 
supply tube, and with cleaning nozzles, such swinging blower arm being 
anchored in a distributing body rotatably mounted on the housing of the 
rotary regenerative heater. On frontal axial bores of the distributing 
body there are combined water and steam inlet piping, in the lateral walls 
there being located bores of the distributing body located above the 
supply tubes provided with the cleaning nozzles. The drive for the 
swinging blower consists of an electric motor with a worm gear unit and 
further with a mechanical gear with a nut and motion screw hinge connected 
to the distributing body. For vapor blasting or water washing the swinging 
blower arm slowly performs a motion at a constant angular speed along a 
part of a circular path from the rotor periphery to the rotor axis and 
returns. Under such conditions the cleaning effect of the cleaning medium 
upon the surface of the rotor is dependent on the angular position of the 
blower arm. This is a disadvantage because the time of working of the 
streams of blowing or sprinkling media and thus also their cleaning 
effects are very different in the part of the rotor near the axis thereof 
in comparison with the parts of the rotor near its circumference. The 
cleaning effect attained upon the part of the rotor near its circumference 
is much less than that attained near the axis of the rotor. Moreover, 
because of the usual arrangement of the outlet conduit for the products of 
combustion, the deposits therefrom are as a rule much more heavily 
deposited upon the rotor near its periphery than near its axis. If it is 
necessary, under these conditions, to clean the peripheral parts of the 
rotor thoroughly by the use of previously employed cleaning blowers, a 
large part of the steam and water energy is wasted in the major part of 
the path of travel of the cleaning nozzles, that is parts of such path 
other than those near the periphery of the rotor. Since such cleaning 
takes place during the operation of the regenerative heat exchanger, such 
practice results in an undesirable increase in the water vapor content in 
the combustion products, and therefore to undesirable local increasing of 
the amount of deposits upon the rotor which result therefrom. 
The present invention has among its objects an elimination of the majority 
of the above-described disadvantages of the known cleaning device. In 
accordance with the invention, a swinging cleaning arm is made adjustable 
through an operating member under various angles with respect to the rotor 
face, whereby the extreme outer position of the cleaning arm during its 
circuit across the rotor is made substantially constant, while the extreme 
radially inner positions thereof are variable. The operating member is 
made like a pressure motor. In the control gear the distribution sections 
are parallelly arranged in the distributing member which is connected 
through connecting piping to a fluid pressure supply, such interconnecting 
piping being connected to the respective pressure spaces of the operating 
member; such distributing section is connected with a controlling member 
through controlling interconnections. 
The device according to the invention permits the choice under operating 
conditions of an optimum blowing cycle, which permits the reduction of the 
power consumption nearly to the optimum necessary minimum. The device 
enables the heat exchange surfaces to be kept practically optimumly clean 
despite changes of operating boiler conditions which change the amount of 
deposits on the heat exchange surfaces of the rotor of the regenerative 
heater. In comparison with blowing device heretofor known, the cleaning 
device of the invention is also more reliable in operation and less 
exacting as to its maintenance.

As shown in FIG. 1, the cleaning device of the invention has a swinging 
blower with an operating member 3 arranged on a part of the box or housing 
of a regenerative heater 1, and a controlling heater 18, shown here in 
block form. Operating member 3 is here shown as a double acting fluid 
motor, the opposite ends of which are connected through piping 13 to one 
section of a distributing member 9 which forms a part of the controlling 
gear 18. Three other distributing members are shown in such controlling 
gear, each of such other parts being connected to similar operating 
members 3 through piping 13. Distributing member 9 is under the control of 
an electric controlling member 10 which is connected to the distributing 
member 9 by an electric interconnection 12. Each of the four sections of 
the distributing member 9 is a self-contained three-position hydraulic 
distributor with an auxiliary electric serevomotor; each of such 
serevomotors is electrically interconnected to the respective outlet of 
the controlling member 10. Through the respective interconnecting pipings 
13, each of the hydraulic distributors of the distributing member 9 is 
connected to the respective outlet of four double-acting hydraulic 
operating members 3, only one of which is shown in FIG. 1. 
Each of the outlets the electric controlling member 10 has four sections 
(not shown), each section being provided with known time switching 
elements, step-by-step selectors, and auxiliary electrical controllers. 
The electric interconnection 12, which is an electric multi-cable 
conductor, connects the outlet of the respective parts of the electric 
controlling member 10 to the respective parts of the distributing member 
9. Electric controlling member 10 is provided with a suitable source of 
electric current, not shown. 
As shown in FIG. 1, the left hand distributing section of the distributing 
member 9 is connected to the upper, illustrated operating member 3 the 
cylinder of which is pivotally connected to the housing of the 
regenerative heater by a hinged connector 14. The second section from the 
left of the distributing member 9 is connected to a lower, unillustrated 
operating member 3, which is disposed on the housing 1 of the regenerative 
heater in the same manner as the upper, illustrated operating member 3, 
but beneath it so as to drive a second swinging arm which mounts a 
cleaning nozzle to clean a second, lower surface of the rotor of the 
regenerative heater. The third and fourth distributing sections (counting 
from the left) of the distributing member are for controlling similar 
upper and lower swinging arms bearing cleaning nozzles for a second 
regenerative heater (not shown). 
As shown in FIG. 1, on the upper end of the housing 1 of the regenerative 
heater thereshown, there is a cross beam 6 with a centrally placed bearing 
7 for the vertical shaft of a rotor 16. The mechanism for rotating the 
rotor 16 of the heater is not shown in FIG. 1. It is to be understood that 
the lower end of the housing 1 of the regenerative heater is provided with 
a cross beam similar to the cross beam 6 shown, and that the lower cross 
beam is also provided with the central bearing for mounting a rotor 
similar to rotor 16, and that parts of the lower rotor cleaning device in 
accordance with the invention are also mounted upon such lower cross beam 
in the same manner as that shown in connection with the upper cleaning 
device. 
In the arrangement shown and described, with each of the rotors, that is 
the upper rotor 16 shown, and the similar rotor employed at the bottom of 
the housing of the regenerative heater, there is installed one swinging 
blower on the cleaning arm 2 of which there is disposed a cleaning nozzle 
(not shown) disposed generally normal to the face of the rotor to be 
cleaned. The outer end of the piston rod 4 of a hydraulic operating member 
3 is pivotally connected to a first end of a control lever 5, the second 
end of lever 5 being fixedly connected to and projecting radially from a 
vertical shaft 15 to the upper end of which the cleaning arm 2 is fixedly 
connected. The reciprocation of the piston rod 4 causes the outer end of 
the cleaning arm 2, upon which the cleaning nozzle is mounted, 
successively to occupy the positions O, a, b, c, d, and e, shown in FIG. 
1. 
Before the cleaning process begins, in controlling member 10 the time 
dwells are set up on the time switching elements and on the step-by-step 
selectors. These parameters determine the lengths of piston travels in the 
respective hydraulic members 3, and thus also the individual inside 
positions a, b, c, d, and e of the cleaning nozzles above the upper and 
beneath the lower faces of the rotating rotors 16. When starting, the 
cleaning device moves each of the cleaning arms 2 with its respective 
cleaning nozzle in accordance with the control thereof by controlling 
member 10 as shown in FIG. 2 from the outer position O along an arc 17 
into the first inside position a. After the cleaning arm 2 has reached 
such first inside position a, on an order from the controlling member 10 
the respective hydraulic gate valves in the sections of the distributing 
member 9 are opened and the free outer end of the cleaning arm 2 returns 
along the arc 17 into the starting position O. After this, on a further 
order from the controlling member 10 the hydraulic gate valves in the 
distributing member 9 are displaced in the opposite direction, and the 
cleaning arm 2 moves from its outer position O into the second inside 
position b. Upon the issuance of further orders by the controlling member 
10, the cleaning arm 2 is successively moved from one next inside position 
c to position d and finally to position e. 
From the final inside position e the cleaning arm is returned to its outer 
position O and the whole cleaning cycle will have been finished. A 
complete cleaning process will consist of several cleaning cycles, in each 
cycle the cleaning arm and the nozzle mounted thereon moving in the manner 
shown in FIG. 2. That is from the position O to position a, back to 
position O and then to position b, back to position O and then to position 
c, etc. The swinging motion of the cleaning arm 2 is in a plane parallel 
with the face of the rotor being cleaned. In every cleaning cycle of the 
cleaning process the amplitude of swinging of the arm 2 is modulated, the 
extreme outer position O of the cleaning arm 2 being in the main constant, 
while its extreme positions a, b, c, d, and e during the cleaning process 
are periodically variable. The time behavior of any cleaning cycle 
including the time dwells of the arm 2 in the extreme positions thereof, 
as well as the order of cleaning of single rotor faces and the number of 
cleaning cycles incorporated in any cleaning process can be preset by 
suitable setting of the time controlling member 10, when required. 
Although the invention is illustrated and described with reference to a 
single preferred embodiment thereof, it is to be expressly understood that 
it is in no way limited to the disclosure of such preferred embodiment but 
is capable of numerous modifications within the scope of the appended 
claims.