Measuring and testing – With fluid pressure – Leakage
Patent
1995-09-28
1999-02-16
Larkin, Daniel S.
Measuring and testing
With fluid pressure
Leakage
73 407, 73 405R, 73 492, G01M 318, G01M 322
Patent
active
058723080
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD OF THE INVENTION
This invention relates to a method of detecting leaks through flaws in heat exchangers and the like.
BACKGROUND
Pasteurisers used in the dairy process industry typically include a product path in which the milk is placed for treatment. A heating and/or cooling medium is passed through a separate circuit in close heat-exchange relationship with the product path via a number of heat exchange plates. Modern pasteurisers of this kind are known as HTST (High Temperature, Short Time) pasteurisers.
From time to time, leaks can develop between the heating/cooling circuit and the product path. Such leaks can be very costly, not only because the contaminated product must be discarded but also due to the cost of finding and rectifying the leak. Present preventive maintenance techniques involve shut down of the plant, dismantling of the pasteuriser,. detailed examination and testing of the individual heat exchange plates using mechanical and/or chemical tests, careful cleaning of the components, re-assembly with new seals, pressure and leak testing, and recommission of the re-assembled pasteuriser. Such a procedure results in considerable lost production time whilst the equipment is out of commission, is extremely labour intensive, and involves the cost of new seals. In addition, there is a substantial risk that further leaks can inadvertently be introduced during the re-building process.
An aim of the present invention may be viewed as being to overcome these problems.
SUMMARY OF THE INVENTION
The present invention proposes a method of testing for leakage.
BRIEF DESCRIPTION OF THE DRAWINGS
The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings:
FIG. 1 is a diagrammatic representation of a dairy pasteuriser undergoing a first testing method in accordance with the invention,
FIG. 2 is a block diagram of ultrasonic detection apparatus for use in a second testing method of the invention, and
FIG. 3 is a diagrammatic representation of a dairy pasteuriser undergoing the second testing method using the apparatus of FIG. 2.
DETAILED DESCRIPTION OF THE DRAWINGS
In FIG. 1, the dairy pasteuriser in question is outlined by dashed lines. The pasteuriser is a form of heat exchanger having a first path A for coolant and a second path B for the milk product. The two paths A and B are in intimate relationship to provide heat exchange between the two paths in normal use so that, should any leaks develop between paths A and B, the product in path B will become contaminated with coolant.
In the method of the invention, the pasteuriser is tested for leaks between paths A and B without any necessity to dismantle the pasteuriser. A donor fluid (see below) is circulated through path A in a closed loop by means of a circulation pump P1, while a recipient fluid (again, see below) is circulated in a closed loop through path B using a pump P2. Contacting type conductivity probes 10 and 12 of known construction are placed in the donor fluid and recipient fluid paths A and B respectively. Each probe is connected via a suitable electronic interface circuit 14, 16 (e.g. a Model 697C1 Conductivity Transmitter available from Great Lakes Instruments, Inc. of Milwaukee, Wis.) to a digital display 18, 20 respectively, which gives a conductivity readout in suitable units such as milli siemens/cm. The probe 12 in the recipient fluid circulation path B is also connected via interface 16 to an electronic circuit 22 that monitors the conductivity reading at regular intervals, stores the reading, and displays the difference between the last two readings (which will be referred to below as value X).
By way of example, clean tap water can be used as the recipient fluid, with a solution of a salt and water as the donor fluid. The donor fluid is usually circulated under a.higher pressure than the recipient fluid, e.g. at 45 psi. Any suitable electrolyte may be used as the
REFERENCES:
patent: 2658728 (1953-11-01), Evans, Jr.
patent: 3425264 (1969-02-01), Frei
patent: 3522008 (1970-07-01), Defabaugh et al.
patent: 4138856 (1979-02-01), Orlowski
patent: 4550688 (1985-11-01), Zuber et al.
patent: 4688627 (1987-08-01), Jean-Luc et al.
patent: 5170840 (1992-12-01), Grunwald
Dorman Ira S.
Larkin Daniel S.
Somerset Technical Laboratories Limited
LandOfFree
Method of testing a plate heat exchanger for leakage 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 of testing a plate heat exchanger for leakage, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of testing a plate heat exchanger for leakage will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2063845