Pumps – Condition responsive control of pump drive motor – By control of electric or magnetic drive motor
Reexamination Certificate
1999-07-16
2001-05-22
Walberg, Teresa (Department: 3742)
Pumps
Condition responsive control of pump drive motor
By control of electric or magnetic drive motor
Reexamination Certificate
active
06234759
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority of Patent Application Ser. No. DE 19831997.5, filed in Germany on Jul. 16, 1998, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a method for regulating the pressure of a fluid that is moved through a system of pipes having at least one consumer. The fluid is moved by a pressure generator driven by an electric motor.
The “fluid” within the meaning of the invention can include, for example, water, steam or gas. The method is used, for example, in locations where increased fluid pressure is required to supply many consumers, such as is the case with multi-storied buildings or hotels where a sufficient pressure is necessary at each water extraction point. The same is also true for large heating plants or gas supply facilities. Accordingly, the “pressure generator” can be a pump or a compressor. As an example of the possible applications, the method is described in the following for a pump-operated water supply.
The maximum pressure necessary for supplying all extraction points connected as consumers to a pipe system for the water supply, for example, can be determined with the aid of a calculation. Even though this maximum pressure is only needed if all consumers want to have water, facilities of this type are consistently operated with a constant maximum pressure, involving a high expenditure of energy for operating the pump units, as well as increased wear on the pumps and valves. Furthermore, maintaining a continuous high pressure will stress the pipes, so that pipe breaks occur relatively frequently. Finally, disturbing flow noises often occur.
It is the object of the invention to improve the above-described method in such a way that the stress on the pipe system with associated units can be reduced.
SUMMARY OF THE INVENTION
This object is solved according to the invention in that:
the motor speed for regulating the pressure in the pipe system is adjusted by a controller with at least one control curve impressed into it, which is designed to reflect the fluid pressure in the pipe system in dependence on the amount of fluid flowing through or the flow speed for the fluid, which control curve extends between a predetermined minimum and a predetermined maximum of the pressure and is uniformly curved in such a way that in the direction of increasing pressure it is located above a straight line, connecting the points of minimum pressure and maximum pressure, and that in the center region between the two points it is at the greatest distance from the line;
an electrical variable that is proportional to the amount of fluid flowing through or the flow speed of said fluid is continuously supplied to the controller as an actual value;
if the actual value deviates from the desired pressure value according to the control curve, the motor speed is adjusted to compensate for this.
With this method, the energy requirement for operating the pump unit is minimized because only the pressure needed to supply actually switched-on consumers is generated continuously. In the process and owing to the curved course of the control curve, the pipe system is constantly provided with a slightly increased amount of pressure, so that the respective fluid starts flowing immediately and with certainty if an extraction point in the pipe system is opened. The control curve furthermore avoids an overshooting or undershooting of the control operation, which could derail the complete process. The wear on pump units and valves is reduced. Pipe breaks can be avoided for the most part because only the pressure necessary for the water to flow is continuously present in the pipe system. Disturbing flow noises do not occur any longer. Finally, it is possible to use smaller pressure compensation containers. The method is suitable in particular for higher pressures above 6 bar.
REFERENCES:
patent: 4248194 (1981-02-01), Drutchas et al.
patent: 5269660 (1993-12-01), Pradelle
patent: 42 43 118 (1994-06-01), None
patent: 0 309 596 (1989-04-01), None
patent: 0 390 627 (1990-10-01), None
patent: 2 293 403 (1996-03-01), None
patent: 62-093498 (1987-04-01), None
patent: 08095645 (1996-04-01), None
patent: 08232883 (1996-09-01), None
Hennel Ewald
Hennel Maik
Hennel Ewald
Kelemen Gabor J.
Patel Vinod D
Venable
Walberg Teresa
LandOfFree
Method for regulating a fluid pressure does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for regulating a fluid pressure, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for regulating a fluid pressure will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2556601