I. Working Principle of the Distilled Water Apparatus
Working Principle:
All types of distilled water apparatuses operate on the fundamental principle that liquids vaporize when heated and condense back into liquid form when cooled, thereby producing distilled water.
II. Precautions and Operating Instructions for the Distilled Water Apparatus
(1) Precautions for Use
1. The outer casing must be properly grounded to prevent electrical hazards.
2. Before each use, the interior of the boiling chamber should be rinsed out; drain any residual water and refill with fresh water. Take care not to damage the protective tin plating on the interior surface.
3. If conditions permit, use deionized water as the water source instead of ordinary tap water.
4. Electric heating should only be activated after the boiling chamber has been filled to the appropriate water level. The water supply must not be interrupted during operation, and the water level should be consistently maintained at the designated fill line; if the chamber runs dry or the water level drops too low, the electric heating element will burn out.
5. When replacing the electric heating element, ensure that the sealing gasket at the water inlet is properly seated to guarantee a watertight seal. Failure to do so may result in water droplets accumulating on the element's terminal, potentially causing an electrical breakdown of the insulation. Additionally, the bolted connections between the wiring and the heating element terminals must be tightened securely; loose connections increase contact resistance, leading to severe overheating and potentially generating electrical sparks that could burn out the heating element's terminal.
6. Regularly remove scale deposits from the inner wall of the evaporation chamber, the surface of the heating element, the inner wall of the condenser, the surface of the condensing tube, and the condenser's water outlet pipe. This prevents compromised condensation efficiency, reduced thermal efficiency, and pipe blockages, thereby extending the equipment's service life.
7. If the apparatus is to remain unused for an extended period, drain all residual water from the unit. It is also advisable to cover the apparatus with a protective cloth cover.
8. Facilitating a heat exchange process involving steam is a reliable method for producing distilled water. By heating water to generate steam—which is then condensed back into liquid form—this apparatus is well-suited for use in pharmaceutical preparation, laboratory analysis, and similar applications. (2) Operating Instructions
1. Open the water inlet valve to fill the evaporation boiler to the standard water level, then close the valve. After powering on the unit to begin operation, open the distilled water outlet valve to allow the distilled water to flow into a designated collection container.
2. The water distiller must be properly connected to an external power circuit.
3. The specific connection method varies depending on the type of power supply used.
Correct Wiring Procedures for Various Scenarios:
① Blown Fuse: This is a common fault, almost certainly indicating a short circuit somewhere in the system. After disconnecting the power, use a multimeter (set to the resistance range) to check whether the heating element wires within each heating tube are shorted to ground. If a ground fault is detected, you may disconnect both ends of that specific heating tube as an emergency measure; the distiller will remain functional, though its total power output and corresponding water production rate will be reduced. Alternatively, the faulty heating tube should be replaced. For example, in a 20 L/h electric water distiller—which typically utilizes a configuration of six heating tubes arranged in three pairs—the tubes within each pair are connected in parallel. Occasionally, a multimeter test performed while the power is off may show no ground fault in the heating element wires; however, after the unit has been powered on for a period, a ground fault develops (due to thermal expansion) and causes the fuse to blow. In such cases, check whether there is a thick buildup of limescale; if so, remove it. If the limescale buildup is not significant, the fault is likely caused by the heating element wire within a specific tube expanding upon heating and making contact with the grounded metal casing.
② Audible Noise and Sparks Upon Switching On: If you hear a loud noise or observe sparks when engaging the power switch, it indicates a short circuit or a poor electrical connection within the wiring, resulting in excessive current flow. In addition to a grounded heating element wire within a heating tube, other potential causes for excessive current include water leakage between a heating tube and the evaporation boiler—which can cause a short circuit at the power terminal—or moisture ingress at the power terminals, leading to arcing and a reduction in the electrical resistance of the terminal insulation board.
③ Decreased Distilled Water Output: As the unit accumulates operating hours, limescale gradually builds up on the heating tubes. This buildup hinders the efficient transfer of heat from the tubes to the water, resulting in a gradual decline in the volume of distilled water produced. When this occurs, the limescale should be removed using either physical or chemical cleaning methods. If there is a sudden and significant drop in water output, it almost certainly indicates that one or more heating element wires have burned out, thereby reducing the total power output and water production rate. Use a multimeter to identify the faulty heating tube(s) and replace them. After replacing a heating tube, fill the boiler with water and observe it carefully to ensure there are no leaks or seepage; the unit must not be powered on for operation until you have confirmed that it is completely watertight.