Liquid purification or separation – Processes – Including controlling process in response to a sensed condition
Patent
1993-11-05
1995-05-23
Drodge, Joseph W.
Liquid purification or separation
Processes
Including controlling process in response to a sensed condition
100 50, 100 99, 210 90, 210 91, 210224, 210400, 210770, 210808, B01D 3380
Patent
active
054178657
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a method of detecting and removing bulges in continuous strips of material before they enter higher pressure zones and a device for carrying out this method.
In dewatering machines in which a filter cake is formed between two belts, this filter cake does not enter the next zone of higher pressure with the belts when its stability is too low. This causes the filter cake or the filter belts to form a "bulge". If the marginal zones are open, the filter cake, e.g. community sludge, brims over the edges and thus pollutes the machine and the environment. In closed machines, this bulge is not detected until the belts get stuck. In order to restart the machine, it must be dismantled and cleaned, which causes extended standstill. The availability of the machine is thus very low, particularly at changing stability of the filter cake.
It is the object of the invention to provide a method for the detection and removal of bulges in continuous strips of material before they enter pressure zones which is free of the above-mentioned drawbacks. This is achieved according to the invention in the method initially mentioned by providing for a sensor to be deflected on the occurrence of a bulge and a control signal to be generated. This means that upstream of each pressure zone, or in case of a plurality of pressure zones, upstream of each one of these pressure zones, a bulge is detected by scanning the upper belt by deflecting a sensor and operating parameters such as machine speed or pressure in the individual pressure zones are controlled by this signal and the bulge is thus removed. This eliminates the cleaning of machines and environment and in case of closed machines the dismantling otherwise required, which considerably increases the availability of the machine.
On the occurrence of bulges caused by pressure, the operating pressure of the respective pressure zone is conveniently reduced step by step until the bulge has disappeared. This operation always results in the adjustment of the highest possible compressive force without causing bulges. This permits an adjustment to the respective material parameters of the filter cake.
A further embodiment of the method is characterized in that on falling short of a limiting value, the pressure in the zone upstream of the belt advancing direction is also reduced.
It is further convenient in the event of falling short of a pressure limiting value of the pressure zone located upstream for the pressure in the pressure zones located further upstream to be correspondingly reduced, the pressure in the individual pressure zones in the belt advancing direction each being equal to or higher than that of the zone upstream. This also automatically adjusts the differential pressure between the individual pressure zones to various conditions of the filter cake and thus permits a maximum dry matter content (maximum dehydration) of the filter cake with retention of operational safety.
It is further convenient to increase the pressure in the respective zone after expiration of a waiting period following the elimination of the bulge. This adjusts the maximum pressure in each zone just below that causing a bulge.
A further object of the invention is a device for carrying out the method according to the invention for the detection and removal of bulges in strips of material before they enter pressure zones, the device being characterized in that is it provided with a preferably pressure-tight sensor which is deflected when a bulge occurs in the strip of material and is resettable when the bulge disappears. This embodiment assures the detection of a bulge in the strip of material at all times.
A convenient embodiment of the device according to the invention is characterized in that the sensor is composed of a proximity switch and a disk moving on the deflection of a pitoval detecting element of the sensor.
The disk is conveniently biassed in the direction of the proximity switch by means of a spring. This provides for a defined location of the disk in its normal position wh
REFERENCES:
patent: 1743117 (1930-01-01), Cooper
patent: 3969668 (1976-07-01), Weinzinger
patent: 4650571 (1987-03-01), Anderson
patent: 4777729 (1988-10-01), Hausler
patent: 4834884 (1989-05-01), Bergloff et al.
patent: 4851119 (1989-07-01), Bergloff et al.
patent: 4855062 (1989-08-01), Oelbermann
patent: 4861495 (1989-08-01), Pietzsch
patent: 5109764 (1992-05-01), Kappel et al.
patent: 5203996 (1993-04-01), Scheucher et al.
Scheucher Peter
Stummer Giselher
Andritz-Patenverwaltungs-Gesellschaft M.B.H.
Drodge Joseph W.
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