Use and Maintenance of Water Bath in Crude Oil Laboratory

1 Internal structure and working principle of constant temperature Water Bath

A stainless steel U-shaped tubular heater is placed horizontally in the constant temperature Water Bath, and an aluminum shelf with holes is placed inside the Water Tank. The upper cover is equipped with combined ferrules of different calibers, which can be adapted to flasks of different calibers. There is a drain pipe on the left side of the constant temperature Water Bath, and an electrical box is on the right side of the constant temperature Water Bath. The front panel of the electrical box is equipped with a temperature control instrument and a power switch . There are electric heating tubes and sensors in the electrical box. The temperature control system adopts high-quality electronic components, which is sensitive to temperature control, reliable in performance and easy to use.

Its working principle is: the sensor converts the temperature of the water in the tank into a resistance value, and after being amplified and compared by the integrated amplifier, it outputs a control signal to effectively control the average heating power of the electric heating tube to keep the water in the tank at a constant temperature.

2 The use of constant temperature Water Bath

(1) In daily work, the tasks of the laboratory are heavy, and the working hours of the Water Bath are long. The water in the Water Bath has been repeatedly added and heated, and the heating tube has been in working condition, which not only affects its heating performance, but also reduces its service life.

(2) The oil stains and sediment on the surface of the planned sampling barrels sent by the well area have not been wiped clean . Although the analysts will wipe them again, in winter, due to the severe cold weather in northern Shaanxi, the soil sticks to the sample barrels, and the crude oil becomes After being heated in a Water Bath , the oil on the outer wall of the sample bucket will all float to the inner wall of the Water Bath, while the sediment will settle the bottom of the Water Bath, causing serious fouling of the heating tube at the bottom .

(3) When adding water to the Water Bath, the movement range is too large or careless, and the water splashes into the electrical box; the water remains on the upper cover and is not dried in time, and seeps into the electrical box through the interface gap, causing damage to electrical components.

3 Common faults and treatment methods of constant temperature Water Bath

3.1 Heating tube

(1) The heating tube emits sparks

After the heating tube has been used for a long time, thick tube scale and scale will accumulate on the surface, which will reduce the heat transfer performance of the electric tube and cause the heat load on the tube surface to exceed the rated allowable damage.

(2) The heating tube does not heat

The heating tube cannot be dry-burned, and the heating part of the electric heating tube should be completely immersed in water, so as to prevent the heat from dissipating quickly and exceeding the allowable heating temperature to damage the electric heating tube. In addition, the lead-out part of the wiring should be exposed on the insulation layer of the heater or outside the heater, so that this part should not be damaged due to overheating. Secondly, the terminal of the electric heating tube should be kept clean and dry, otherwise it will reduce the insulation performance and be broken down by a short circuit.

3.2 Temperature control display

(1) The power indicator is on, but the temperature control display is off

Check whether the output of the temperature controller is normal. This kind of failure is generally caused by the transformer on the temperature controller being broken or the phenomenon of virtual welding during use. Find the cause of the failure and deal .

(2) The temperature controller displays normal, but does not heat,

It indicates that the heating tube is damaged. If the heating tube is confirmed to be normal, the relay is generally damaged.

(3) The power indicator is normal, but the temperature controller has no digital display.

Most of this kind of failure is caused by the voltage stabilizing element on the temperature controller heating up during long-term use, causing a breakpoint in the solder joint, or it may be caused by a virtual soldering phenomenon when the temperature controller leaves the factory , and it can be re-soldered.

(4) The working temperature shows that it has greatly exceeded the set temperature for a long time,

Observe whether the heating indicator light goes out after reaching the set temperature. If it goes out, it means that the temperature controller is normal, and only need to replace the relay. If the heating indicator light is always on, the temperature controller is broken and needs to be replaced. damaged, replace it and try again.

(5) If the temperature controller has 999, 000, LLL, HHH beating and there is an alarm output,

If 999 or 000 appears, the sensor is disconnected. If LLL or half HHH appears, the sensor is short-circuited. Replace the temperature sensor. If this happens again shortly after the replacement, check whether If there is a leak, replace it together.

3.3 The temperature cannot be increased after using for a period of time

Generally, the resistance of the heating tube increases or the connection line between the heating tube and the heating tube corrodes, resulting in a large contact resistance. The former needs to replace the heating tube, and the latter cuts off the wire at the connection, and cleans the rusted part of the heating tube joint. , the two methods of judging can be by visual inspection.

4 Daily maintenance method of constant temperature Water Bath

(1) Clean the instrument immediately after using the Water Bath. Drain the water in the Water Bath , use a brush to gently brush off the coarse debris in the Water Bath, and clean the pot. Wipe the inner and outer surfaces of the Water Bath with a soft cloth, and then dry it with a clean cloth.

(2) There should be no water droplets on the inner surface of the equipment, and the outer surface of the equipment should be bright and clean without stains.

(3) When the Water Bath is in use, it needs to be reliably grounded, and the water cannot overflow into the control box.

5 Conclusion

The above points are the attention points that we often encounter when using a constant temperature Water Bath that may damage the heating tube. Longer life. Standardized use of Water Baths and reasonable maintenance can greatly extend the service life of Water Baths, which is also a small measure for cost control.