Condensate evaporator with spark-free float switch

Abstract

Condensate evaporator with a spark-free float switch, characterized in that the switching process for the heating elements (5) used is magnetically detected by a semiconductor Hall sensor (6). This Hall sensor is powered by +5 VDC, separated from the mains voltage by a protective transformer. The switching signal is fed to an optocoupler with zero-crossing detection. This optocoupler activates the semiconductor triac (7), which switches the 230 VAC 50 Hz at zero crossing. Thus, only full half-waves or full waves reach the heater.

Description

[0001] Condensate evaporators are used in plug-in refrigerated cabinets, refrigerated counters, or freezer chests installed in supermarkets and gas stations to cool packaged and unpackaged food. The device is cooled using a refrigerant circuit based on the Carnot principle, in which condensate forms due to temperature differences. Condensate evaporators are used to collect and evaporate the condensate. These collect the condensate and evaporate it using an electric heater. Various types of condensate evaporators are available on the market, equipped with either heating mats or heating elements without a float switch, or alternatively with heating elements that generate sparks when switched on.

[0002] The invention defined in claim 1 is based on the problem of creating a condensate evaporator that enables operation in refrigerated cabinets with new, flammable refrigerants through a spark-free circuit, while simultaneously being energy-efficient. The float switch ensures that the condensate evaporator only heats up and consumes energy when condensate is present in the designated tray. No energy is consumed in the so-called standby mode.

[0003] This problem is solved by the features listed in claim 1. The invention enables refrigerated cabinets of newer designs that operate with flammable refrigerants to be operated safely and energy-efficiently with a spark-free float switch.

[0004] The technical design of the condensate evaporator ensures conformity with EN60079-0:2012 + A11:2013 and the devices carry the

[0005] Ex marking II 3G Ex nA IIA T3 Gc.

[0006] The components used are identified in the attached drawings: Fig. 1 condensation water evaporator series 2780X Fig. 2 Structure of the switching components in the housing

[0007] The switching process for the heating elements is magnetically detected by a semiconductor Hall sensor (6). This Hall sensor is powered by a +5 VDC power supply, separated from the mains voltage by a protective transformer. The switching signal is then fed to an optocoupler with zero-crossing detection. This optocoupler activates the semiconductor triac (7), which switches the 230 VAC 50 Hz at zero crossing. This means that only full half-waves or full waves reach the heater. Mains interference is thus eliminated. Sparking is prevented because there are no mechanical switching contacts and the switching takes place in the hermetically sealed semiconductor triac (7). The heating elements used are equipped with PTC elements, which limit both temperature and power and provide an additional safety feature during operation.

[0008] A Gastronorm tray (10) made of 1.4301 is used to collect the condensate, onto which a polycarbonate housing (3) with protection rating IP 65 is screwed. The circuit board (9) is screwed into the housing, onto which, among other components, a Hall sensor (6), semiconductor triac (7), rectifier (11), and heat sink (8) are mounted. The switching process is determined by the threaded pin (1), Hall sensor (6), float (2) made of 1.4404, and neodymium magnet (4). The threaded pin (1) is screwed into the polycarbonate housing (3) through a threaded hole and secured with a threaded nut. The float (2) is pushed upwards by the condensate accumulating in the housing (10) and the neodymium magnet (4) attached to the end of the float rod (12) switches on the heating rods (5) screwed into the housing (3) as soon as the magnet (4) is in the area of ​​the Hall sensor (6).

[0009] As soon as the condensate level drops, the float with the neodymium magnet (4) moves downwards, the contact with the Hall sensor (6) is interrupted and the heating elements are switched off.

Claims

[1] Condensate evaporator with spark-free float switch, characterized by The switching process for the heating elements (5) used is magnetically detected by a semiconductor Hall sensor (6). This Hall sensor is powered by +5 VDC, separated from the mains voltage by a protective transformer. The switching signal is fed to an optocoupler with zero-crossing detection. This optocoupler activates the semiconductor triac (7), which switches the 230 VAC 50 Hz at zero crossing. Thus, only full half-waves or full waves reach the heater. [2] Condensate evaporator according to claim 1, characterized by that the switching process is triggered by a neodymium magnet (4) pressed into the upper end of the float rod (12) made of 1.4404. [3] Condensate evaporator according to claim 1, characterized by that the Hall sensor (6) required for the switching process as well as the other semiconductors are installed on a “multilayer circuit board DE104”. [4] Condensate evaporator according to claim 1, characterized by that all electrical components are installed in a polycarbonate housing (3) with protection class IP65, which is screwed onto a stainless steel Gastronorm tub (10) made of 1.4301. [5] Condensate evaporator according to claim 1, characterized by that the float rod is guided by means of an adjustable threaded pin (1) made of polyamide and for this purpose a threaded hole is provided on the underside of the housing (3). [6] Condensate evaporator according to claim 1, characterized by that the heating elements (5) bent at a 90° angle are PTC controlled, are screwed into the polycarbonate housing (3) and are made of Incoloy 800.

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