1. The application of atmospheric consistometer
a. Before testing the free fluid, rheology, and fluid loss, the cement slurry prepared must be stirred for 20min (remove gas).
b. It can be used as the portable and practical equipment to check the thickening time roughly in the field operation.
c. The atmospheric consistometer is more portable than the pressurized consistometer when do the atmospheric experiment. If the cement property is not good or the cement is not compatible with the additives, the cement slurry will produce the phenomenon of “instant setting”. It is faster to carry out the sample from the atmospheric consistometer than the pressurized consistometer. That can reduce the damage of the pressurized consistometer and the electronic instrument pointer. If happen the “instant setting”phenomenon during the testing progress, the thickening pointer will deflect quickly. With this phenomenon, the laboratory staff can take out the sample quickly and do the adjustment.
2 the structure of the atmospheric consistometer
The atmospheric consistometer is made up of a 15 liter stainless steel sink which is equipped with a cement slurry cup. The temperature control instrumentation is used to set, control and display the temperature, the temperature scope is from the room temperature to 93℃. A 1.5 KW heaters controlled by thermocouple and temperature controller heats. Reducer motor drives conveyor belt and leads the slurry cup spinning. The slurry cup rotation speed is 150 r/min. Further more, it also drives the blade of the sink to stir thick oil, and makes the temperature inside the tank evenly distributed. The thick oil injected should just reach the bottom of the rotating engine; its height is as high as the spill valve’s behind the cistern. The spill valve is the final level calibration.
3. The type of atmospheric consistometer
a. Simply consistometer
It not has the thickening determination recorder, can't determine the consistency and check thickening-time; also it can't see the stand or fall of slurry system; it had only a stirring slurry role.
b. Digital ＆ record type consistometer
It equip with the recorder which can record the thickening variation and show the actual temperature. Set the stirring time, you can read the cement slurry’s consistency and estimate the thickening-time. You can test if the cement slurry system is stand or fall. It is simpler than the pressurized consistometer and also it can reduce the damage to the pressurized consistometer.
c. Smart type consistometer
It is an integrated instrument which is constituted by the atmospheric consistometer, micro-computer and printer. Set the temperature and stir time on microcomputer, the thickening-time curve of cement slurry during mixing process can display on the consistometer, and the result can be printed out.
4 The application of atmospheric consistometer
Before the experiment, turn on the power and heater, heating to the set temperature, put the prepared cement slurry into the slurry cup up to the scale quickly, and insert the blade into the slurry cup. Put the top of blade into the groove at the bottom of the cup. Cover it and put the slurry cup into the rotator groove, start the power. The time from slurry prepared to power start not longer than 1 min.
Before preparing the cement slurry, check that if the slurry cup is clean or not. Especially, the top of blade and inner pin should not be damaged. Rotate the blade to check if the blade top is set into the cup bottom groove. If there is not any phenomenon mentioned above, pour the slurry into the cup. But if there is one of the phenomenons, you should change pin or blade or you should clean the slurry cup again.
5 the maintenance of the atmospheric consistometer
Every day: after the experiment, clean the slurry cup and blade completely.
Every month: Check whether the blades have been bent and the axis pointer is worn (put the blade in position, gently rotating blade, feel whether the friction between the blade and plasma cup bottom or around is serious), if it is serious, must replace new blade.
Use mercury thermometer to calibrate the temperature display instrument.