1. The application of pressurized curing kettle
This device is designed and manufactured in accordance with the API specification, and it is used to curing the set cement under the high pressure and temperature condition for the compressive strength experiment.
2. The structure of pressurized curing kettle
The curing kettle is equipped with pressure kettle, pressurized pump, pneumatic hydraulic pipeline system, temperature controller, heater, electrical control device, stainless steel kettle body, water-cooling system and warning system.
The pressure kettle is constituted by a stainless steel kettle body with cover. And there are kettle cap with screw and seal ring on it. It is used to seal and increase pressure. There are two coolers inside the kettle and a 2500W heater outside the kettle. The inside pressure is provide by the pressurized pump. The water flow by the tube, filter and valves and is pressed into the kettle by the compressed air. Then increase the pressure with pressurized pump.
There are two thermocouples in the curing kettle. They are used to determine the temperature of water bath temperature and cement separately. The thermo controller displays the temperature and control the operation to increase and keep the temperature. The pressure inside the kettle is displayed by the pressure meter. In the high pressure water pipe, the pressure release valve is equipped with water filter joint which is used to filter the cement particles and so on.
The pressure on or off system is installed in the pressure gage and it is a safe device with a rating pressure scope. If the pressure decreases or increases to a pressure which is not in the defined pressure scope, the heater will turn off automatically. There is a pressure release valve in the pipeline system. In the API regular experiment, the pressure is 20.7MPa. And when the experiment is over, open the release valve to release the pressure.
The pressurized curing kettle includes single cylinder curing kettle and double cylinder curing kettle.
3. The operation of pressurized curing kettle
a. Before the experiment, turn on the power, and make the other switches on the off state.
b. Turn on the water-in valve; make the water level coming to the thermocouple and the turn off the water-in valve.
c. Put the testing model into the curing kettle, screw on the cover and screw on the nut tightly.
d. Insert the inner thermocouple; screw on the inner nut, don’t tightened, reserve a few screws. Turn on the water-in valve until the water overflowing from the inner screw and then tighten the inner screw.
e. Turn on the air-supplier and pump. Make the pressure up to the required pressure.
f. Set the curing temperature and time with the temperature controller, run the procedure, turn on the heater and begin the curing test.
g. The heater stops heating automatically if the test will stop in 1 hour and 45 min. then the auto cool begins.
h. Shut the water-in valve if the test will stop in 45 min. Open the pressure release valve, release the pressure slowly.
i. Open the air-in valve, evaluate the water and shut the air-in valve.
j. Pick out the inner thermocouple, open the cover and pick out the testing model. Put the out-model sample into the water channel at atmospheric temperature for 30 min. then clean the sample and test the compressive strength.
4. The maintenance of pressurized curing kettle
a. Keep and lubricate the kettle screw, seal ring to prevent the mental surface being scratched.
b. If there are cement particles in the bottom of kettle, clean them to prevent the pipeline from blocking.
c. If the pressure release valve is damaged by the other particles, replace it. and the water filer joint also should be washed commonly.
d. If the kettle cover is leaky, it is probably caused by the poor connect between the seal ring and relative surface. Polish the contact surface with sand paper. If it not run, change the seal ring.
a. The temperature controller has no reading
Cause: 1.power is turn off 2. No power, check the line.
b. The temperature display Sbr
Cause: thermocouple is cut
c. The curing kettle not warm after heating
Cause: 1. the heater is turn off 2. The heater is short circuit.
d. Pressurize slowly
Cause: 1. check if the water supply is sufficient 2. Check if the pipe is blocked 3. Check if the air supply is sufficient 4. Check if there is air or water leakage phenomenon.
e. The pump working abnormally
Cause: 1. pump piston is locked 2. Pump valve has impurity.
Solution methods: 1. increase the air drive power slowly, and decrease the pump circuit speed 2. Maintain the pump.