|Número de publicación||WO1994011306 A1|
|Tipo de publicación||Solicitud|
|Número de solicitud||PCT/DK1993/000367|
|Fecha de publicación||26 May 1994|
|Fecha de presentación||10 Nov 1993|
|Fecha de prioridad||12 Nov 1992|
|Número de publicación||PCT/1993/367, PCT/DK/1993/000367, PCT/DK/1993/00367, PCT/DK/93/000367, PCT/DK/93/00367, PCT/DK1993/000367, PCT/DK1993/00367, PCT/DK1993000367, PCT/DK199300367, PCT/DK93/000367, PCT/DK93/00367, PCT/DK93000367, PCT/DK9300367, WO 1994/011306 A1, WO 1994011306 A1, WO 1994011306A1, WO 9411306 A1, WO 9411306A1, WO-A1-1994011306, WO-A1-9411306, WO1994/011306A1, WO1994011306 A1, WO1994011306A1, WO9411306 A1, WO9411306A1|
|Solicitante||Wandt Hans Ole|
|Exportar cita||BiBTeX, EndNote, RefMan|
|Citas de patentes (5), Clasificaciones (9), Eventos legales (6)|
|Enlaces externos: Patentscope, Espacenet|
METHOD OF AVOIDING CALCAREOUS DEPOSITS ON HEATED, WATER-COOLED TOOLS, COOLER FOR THE IMPLEMENTATION OF THE METHOD AND USE OF SAID COOLER.
The invention relates to a method of preventing calcareous deposits on heated, water-cooled tools, for example welding or moulding tools for use in the drug and food industry, or for example rollers or bearings for use in the graphic industry, where the cooling water is used to ensure a par¬ ticular temperature and an even distribution of tempera¬ ture, the temperature of the tool being app. 90-120°C, whereas the temperature of the cooling water in continuous operation never exceeds 30°C.
In such methods the purity of the cooling water calls for special attention, and up to know it has been common practice to use tap water in large quantities because tap water meets the requirements for purity as stipulated by the health authorities.
According to the present invention, use is made of re¬ circulated cooling water, which is regenerated and cooled continuously.
This method is very economical, in part because tap water is becoming an expensive commodity, and in part because a better utilization of waste heat is achieved.
According to the invention, the regeneration may consist in decomposition or removal of the calcium from the cooling water.
Calcareous deposits on the tools are hereby avoided.
In addition hereto, the regeneration according to the in- vention may consist in radiation of the cooling water with ultra-violet light.
It is hereby possible to sterilize the water to such a degree that it meets the standards established by the health authorities.
A decisive embodiment of the method according to the inven¬ tion consists in that in the event of an interruption of operation - intended or unintended - cooling of the cool¬ ing water continues for so long that the temperature of the tools decreases to about 30°C.
Since the tools are normally operated under a temperature of between 90-120°C, calcareous deposits may occur follow¬ ing an interruption of operations because calcareous de¬ posits may occur already at temperatures of app. 45°C. By carrying out a subsequent cooling to the effect that the tools are brought down below this temperature relatively fast, the calcareous deposits are to a large extent re¬ duced.
The invention also relates to a cooling unit for use in the implementation of the invention, and the cooling unit is advantageous in that the unit has means for recirculation and continuous regeneration of the cooling water, as well as means for cooling down the cooling water, in addition to which the cooling unit may have means for decomposition of calcium carbonat or radiation of the cooling water with ultraviolet light.
The method according to the invention and a cooling unit for use in the implementation of the method will be explained below in the detailed description with reference to the drawing, wherein Fig. 1 is a schematic illustration of a prior art cooling unit,
Fig. 2 is a schematic illustration of a recirculation unit according to the invention.
Fig. 1 illustrates a prior art cooling unit comprising an apparatus 14, which contains welding or moulding tools for use in the drug or food industry. The temperature of these tools is app. 90-120°C during operation and must be cooled by means of cooling water in order to maintain this tem¬ perature. In view hereof, the cooling unit has an open water tank 15, which serves as a cooling water reservoir for the apparatus 14.
A pump 6 is connected to the water tank 15 and is adapted to pump the cooling water from the water tank 15 to the apparatus 14 through an inlet 13, whereupon the cooling water is discharged to the atmosphere through an outlet 12. The water tank 15 therefore must be replenished con¬ tinuously in order to compensate for the loss of cooling water, which is in part discharged and in part evaporates during operation of the apparatus 14 and from the open water tank 15.
The loss of cooling water is compensated for by intake of tap water through a feed pipe 2 as a float valve 1 has sunk to a predetermined lower level in the water tank 15. Thus clean and fresh tap water is fed continuously into the re- circulation unit and together herewith, also calcium from the calcareous tap water.
At the temperature indicated the cooling water will deposit calcium on the machine tools, since such deposits will take place already at temperatures of app. 45°C. Thus a steadily increasing layer of calcium will deposit on the machine tools, and this calcium must be removed from time to time in order to reduce the comsumption of energy necessary for heating the machine tools.
Removal of the calcium in the known recirculation unit in¬ volves a considerable amount of labour, and the discharge of cooling water a considerable waste of water.
In the recirculation unit illustrated in Fig. 2 according to the invention the calcium deposit is reduced to a mini¬ mum, and therefore this unit is considerably more economi¬ cal in operation, discharge of the tap water is avoided during recirculation and sterilization of the cooling water, and a satisfactory • level of purity and a quality, which meet the requirements stipulated by the health authorities is achieved.
The recirculation unit according to invention also com¬ prises a water tank 15, which can be replenished with tap water through a feed pipe 2, which opens by means of a float valve 1, and the cooling water is pumped into the en¬ tire unit by means of a pump 6.
The cooling water is led through an inlet 19, a thermostat 9 and a calcium decomposition element 7, wherein the calcium is removed from the cooling water, whereupon the cooling water is led further through the pump 6 and the inlet 13 to the apparatus 14, wherein the machine tools are cooled, the cooling water being at the same time heated to app. 20°C. The heated cooling water is returned through an outlet 12 and another calcium decomposition element 11 to an evaporator 16 provided in the water tank 15, the heat from the cooling water being utilized to evaporate freon in the evaporator 16. The freon is led through the evaporator 16 in the direction opposite the direction of flow of the cooling water, which will cause the heat from the cooling water to get into contact with as much freon as possible. In the evaporator 16 the cooling water is led through a pipe provided with an undulating wall, or similar formed wall, in order to obtain the maximum surface possible for the heat exchange.
The cooling water leaves the evaporator 16 at a temperature of app. 20°C through a water outlet 20, which is so formed that the water circulates around in the water tank 15 to the effect that a whirl is created. This causes the water in the water tank 15 to be moving constantly. In the water tank is further provided an element 10 for emittance of ultraviolet radiation which serves to sterilize the water in the water tank 15, and this sterilization process is im- proved due to the constant movement of the water.
The heated or evaporated freon is then cooled down in a per se commonly known cooling unit comprising a condensor 3, a motor-driven fan 18, a pipe line 21, a compressor 4, a re- ceiver 5 and a valve 8.
The cooling unit may advantageously be provided with wheels, thus rendering the apparatus mobile.
|Patente citada||Fecha de presentación||Fecha de publicación||Solicitante||Título|
|WO1981002529A1 *||11 Mar 1981||17 Sep 1981||White Light Ind Inc||Magnetic water conditioner apparatus|
|EP0346540A1 *||15 Jun 1988||20 Dic 1989||NUMOR SYSTEMS COMPANY, a Michigan Co-Partnership||Coolant processing system|
|GB2179128A *||Título no disponible|
|US4850427 *||11 Dic 1987||25 Jul 1989||Commissariat A L'energie Atomique||Device for controlling overheating and scaling in an apparatus for heating a fluid and apparatus equipped with such a device|
|US5184471 *||8 Jul 1991||9 Feb 1993||Ocs Industries, Inc.||Food products chiller and method of using the same|
|Clasificación internacional||F25D17/02, C02F5/02, C02F1/32|
|Clasificación cooperativa||F25D17/02, C02F5/025, C02F1/32|
|Clasificación europea||F25D17/02, C02F5/02C, C02F1/32|
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