A METHOD AND APPARATUS FOR MONITORING AND RECONDITIONING THE FLOW OF LIQUID IN HEATING AND COOLING SYSTEMS

Abstract: A method for continuously monitoring and reconditioning the liquid flow in heating and cooling systems, wherein the system liquid, for instance water which may possibly contain standard additives, such as alcohol or glycol, is monitored and reconditioned in several mutually sequential steps within an apparatus unit integrated with the system, by taking from the total or main liquid flow a part flow which is returned to the main flow subsequent to reconditioning. The reconditioning process includes the following steps - subsequent to viewing the liquid by means of a viewing glass: magnetic filtration for removing magnetite particles; filtering-off solid particles (fine particles); removing corrosive gases; deaerating the system; measuring pH, oxygen content and conductivity, wherein an optical and/or electrical alarm signal is given in the event of deviations from mutually related liquid control-values inserted in the apparatus, or in the event of disturbances in operation. Apparatus for carrying out the method consists of a system-integrated unit which includes auxiliary devices for carrying out said part-operations successively.

Description: A Method and Apparatus for Monitoring and Reconditioning the Flow of Liquid in Heating and Cooling Systems The present invention relates to a method and apparatus for monitoring and reconditioning system liquid, i.e. the flow of liquid in heating and cooling systems, the method being characterized by monitoring and recon¬ ditioning the system liquid continuously in a part flow removed from the system and returning said part flow to the system subsequent to reconditioning. Radiators can be mentioned as an example of heating systems, while air-conditioning systems are examples of cooling sys¬ tems. The term system liquid embraces, primarily, system water, which may possibly contain standard chemicals, such as glycol or alcohol. By reconditioning the system liquid of heating and cooling systems is meant here treating the liquid mec¬ hanically, chemically or physically-chemically in a manner to halt corrosion that is present in the system, to remove slime, precipitations and coatings from said system, and to prevent any future corrosion, slime formation and deposits from occurring. Those problems normally encountered in heating and cooling systems can be divided into the following groups: Acute Problems: - Leakages and stoppages in circulation can be included here. Operational Disturbances: - The constant need to replenish the system with thinning liquid. The recurring need to repair corrosion damage. - The frequent replacement of worn seals in the system. - The system is unable to manage peak loads. - The system exhibits circulation disturbances. Higher Energy Costs: Delivery of over-temperatures. - Poor heat yield in heat emitting surfaces. Recurrent Complaints to the Manufacturer of the Heating or Cooling System: - Uneven climate distribution. - High operating costs. - Recurring breakdowns in operation. - Too cold in winter or too hot in summer. All of the aforesaid problems can, in many instances, be due to the fact that the system liquid has a poor chemical or physical-chemical condition, i.e. the liquid has a composition or properties which cause corrosion, which in turn can result in leakage. The liquid may, for instance, have an unsuitable pH-value, i.e. a pH-value which does not lie within the recom¬ mended range of 8.5-9.5 in the case of heating-system water, or may have a conductivity (salt content) which is too high and which does not lie beneath 200 μS/cm as recommended for heating-system water, or an excessively high oxygen content, i.e. an oxygen content which does not lie beneath the recommended value of 0.05 mg/1 at 95 * C. Another problem is that the formation of slime in the liquid can result in operational disturbances, while deposits and coatings result in energy losses. Another common problem is the occurrence of large or small air bubbles in the system liquid, which results in lower heat yields. Methods and apparatus for avoiding at least some of the aforementioned problems have been described and used. For example, Patent NO 160546 teaches apparatus for venting or purging a closed liquid system in a manner as to remove small air bubbles or vapour bubbles, by causing the bubbles to agglomerate into larger bubbles of greater buoyancy, and thereafter removing the bub¬ bles from the system by means of said apparatus. In this case, the whole of the liquid flow passes through the apparatus. U.S. 4,413,675 describes a filter and a viewing glass incorporated in the cooling system and located in the direct total flow between a motor and a radiator. A transparent conduit incorporating double, conical screens or filters are intended to prevent blockaging of the radiator, and the arrangement also enables the operation of the cooling-water pump and thermostat to be checked visually and indicates corrosive liquid and relative flow. The arrangement is said to be suitable for installation in the cooling system of internal combustion engines. The total cooling-liquid flow passes through the arrangement before said flow is passed to the radiator. It is necessary to remove and clean the filters when the need arises, during which time the system is unavoidably out of operation. U.S. 4,793,403 teaches a method of cleaning the cooling system of an internal combustion engine, wherein the whole of the cooling liquid is passed to a zone (a device) located externally of the cooling system, where the liquid is treated in a manner to remove particles of rust, deposits and slime. This treatment requires the steps of filtering-off contaminants, adding chemi¬ cals, such as corrosion inhibitors, adding means for adjusting the pH and an anti-corrosion agent, returning the cooling liquid from the treatment zone to the engine cooling system, and filtering the returning cooling liquid. As in the former case, it is also necessary to dis¬ mantle this system for cleaning purposes, during which time the system must be taken out of operation. Finally, the broschyr ASEA-ATOM B R 75 describes the cleansing of turbine-condensation water by filtering the water prior to returning said water to the reactor, and also the cleansing of reactor water, by removing anionic and suspended impurities such as to impart a specified degree of purity to the water in the reactor vessel, by means of two parallel ion-exchange units consisting of radial-flow bed filters. Distinct from the aforedescribed, known technology, in which certain conditioning stages are carried out discontinuously, i.e. with associated interruptions in system operation, and on the total flow of water in the system, the present invention relates to a method and apparatus for continuously monitoring and improving the condition of system liquid, by removing a part flow of the system liquid, e.g. the system water of a heating or cooling system, and monitoring and subsequently con¬ ditioning the liquid in a given order of treatment steps within one and the same apparatus unit incor¬ porated in said system, said steps comprising: - measuring the instantaneous liquid flow and checking the appearance of the system liquid with the aid of a viewing glass; - filtering-off, for example, magnetite with the aid of a magnet filter; - optimally filtering-off particles down to a particle size of 0.5 μg; - removing all corrosive gases: - venting the entire system; - measuring pH, oxygen content and conductivity. The reconditioning system also includes alarm devices which function to produce an optical and/or electrical alarm signal in the event of an operational disturbance and/or when the system liquid is in poor condition, thus when, for instance, filtering-off particles, measuring the liquid flow, and when measuring pH, oxygen content and conductivity. The inventive apparatus is installed for the purpose of alleviating maintenance and for preventing the need for maintenance and, as before mentioned, is operated without interrupting the normal operation for system liquid, since the necessary cleaning or exchange of, for instance, filters is effected in a branched part flow which, subsequent to reconditioning, is returned to the total supply system. The aforesaid conditioning steps need not necessarily be carried out in the aforesaid order, and the steps may be mutually reversed when considered suitable. The individual steps are carried out with the aid of known auxiliary devices, which do not form part of the inven¬ tion as such. The essential feature of the present invention is that the different, individual condition¬ ing steps are carried out successively, without inter- rupting the function of the system as a whole. Those tests carried out have shown that the inventive ap¬ paratus and inventive method are able to improve the condition of the water in a "physical-mechanical" manner to such an extent as to enable the earlier applied chemical treatment to be omitted, even in the case of systems in which the system water is very poor. The accompanying drawings illustrate schematically an advantageous embodiment of the invention, i.e. succes- sive reconditioning steps carried out in a part flow of a liquid-filled supply system. The drawing illustrates: 1. A flow meter with viewing glass (system liquid in poor condition). 2. Magnetic filtering. 3. Particle filtration (fine filtration). 4. Degassing/deaeration or purging. 5. Measuring/control of a. pH b. oxygen content c. conductivity 6. Alarm and monitoring unit (system liquid in good condition).

Claims: ≤laiaiε 1. A method for monitoring and reconditioning the liquid flow of a heating or cooling system, wherein the system liquid is checked and freed from foreign, harm- ful solid and gaseous substances, c h a r a c ¬ t e r i z e d by monitoring and reconditioning the system liquid continuously, without interrupting normal system function by effecting reconditioning in a plura¬ lity of sequential steps within an apparatus unit incorporated in the system and on a part flow separated from the main liquid flow, and returning said part flow to the main flow subsequent to reconditioning, said reconditioning steps including: - measuring the instantaneous liquid flow and viewing the system liquid with the aid of a viewing glass included in said apparatus unit; - magnetically filtering-off any particles of mag¬ netite which may be present; - filtering-off solid particles (fine filtration); - removing corrosive gases; - deaerating the system; - measuring pH, oxygen content and conductivity, wherein the order of said different part steps may be reversed when necessary, and wherein the apparatus produces an optical and/or electrical alarm signal in the event of deviations from mutually related control values inserted in said apparatus, these deviations indicating that the system liquid is in a poor condi¬ tion or an interruption in operation. 2. Apparatus for carrying out the method according to Claim 1 for monitoring and reconditioning the liquid flow in a heating or cooling system, c h a r a c ¬ t e r i z e d in that the apparatus comprises an integrated unit which is connected to a part flow taken from the main flow and which includes the following successive auxiliary devices: a flow meter with viewing glass for viewing system liquid in poor condition, - magnetic filter (2) for removing particles of magnetite, - filter (3) for removing solid particles (fine fil tration): - means (4) for removing corrosive gases and for deaerating the system; - means (5) for measuring oxygen content and conduc¬ tivity; and - alarm means (6) for producing an optical and/or electrical alarm signal in the event of deviations from mutually related control values inserted in the apparatus, or an interruption in operation.

Inventors: CARLSSON BJOERN, JOHANNESSON JOE, SVENSSON SVEN-GUNNAR, CARLSSON, BJOERN, JOHANNESSON, JOE, SVENSSON, SVEN-GUNNAR
Applicants: GLOBAL ENERGY SERVICE AB, GLOBAL ENERGI SERVICE AB
Application year: 1991
Main classification: F24D19
IPC codes: F24D19