The application of roots vacuum pump in the preparation of grease
In the process of the preparation of the grease, sometimes inevitably some mixed with air, as a result of the existence of the air, make the product appearance muddy dark opaque, grease is more serious is that make the products in the process of packing density loose, storage stability and colloidal stability is bad, the serious influence product quality, and the address. For this reason, the technical means of vacuum must be adopted to prevent the air rod from entering or discharging the air that has been mixed.
(1) process flow of preparing grease with prefabricated soap. The second half runs in closed pipes. In order to avoid mixing the prepared soap with the base oil into the air when mixing, the vacuum mixing is adopted. That is, the pre-made soap and base oil are added to the mixing kettle according to a certain proportion, and then the vacuum (around 160mmHg) of the mixing kettle is pumped by the vacuum pump, and then the agitator is started to be mixed. In this way, the finished grease does not need to be degassed.
(2) the dehydration and degassing process flow of the contactor and the mixing kettle is the lipid production process flow of the contact device and the homogenizer. When the contactor after saponification temperature to of the refining temperature, put the contactor of pressure valve to open the first to put pressure, when the pressure inside the contactor to atmospheric pressure, most of the water vapor in the process of putting pressure to get removal, with a vacuum pump on the contactor vacuum (vacuum degree is about 600 ~ 660 MMHG) in order to further removal of trace water vapor. Then use the inert gas to press the material in the contactor into the mixing tank to cool and prepare the grease. In addition, there is also a method of not putting pressure on the contactor, but using the pressure generated by the contactor itself (when preparing calcium base grease, it is 5-6kg /cm2). When preparing the file base grease, it is 8kg/ CMT. When the material is pressed into the mixing tank, spray and dehydrate it. Meanwhile, vacuum the mixing tank (about 600-660mmhg) to remove the water vapor.
(3) degassing of the finished grease some of the grease shall be degassed in the finished product processing process. To take off the tank degassing, in a volume of 8 ~ 4 m3 tank top with vacuum equipment to fit, then the vacuity achieve above 600 MMHG, and then use the grease pump from the top of the tank into, when in the process of falling and grease can be dehydrated. . In order to increase the degassing effect, take off the top of the tank in the outlet of the grease, best with a size of 3 mm hole board or aperture sieve plate is 3 mm wide, then falling grease into strips or flake. If one degassing is not complete, degassing or circulating dehydration can be repeated until required. After degassing, the grease can be packed.
Another way is to use to take off the tank degassing, namely in a volume of 16 ~ 20 m after upper air tank vacuum (vacuum in the range of 560 ~ 750 MMHG), put grease by upper slowly through the orifice (pore size is 3 mm) or sieve plate (gap is 3 mm). The upper part of the gas tank shall have at least 30~40% space, which is the expansion space for degassing. The vacuum pump shall be stopped after 2~10 hours of vacuum extraction, and then sealed storage or finished product packaging shall be carried out.
(4) the finished the dehydration of the grease some grease in the process of preparation, because dehydration is completely, or in the pipeline and equipment with the trace amounts of moisture, so that the finished products of fat drop point instability, consistency softened, and prone to corrosion. Therefore, it is important to dehydrate the finished product before packaging it. Some manufacturers are using heating vacuum encapsulation-dehydration abroad at present, namely the finished product fat in blending kettle after heating to 65 ~ 93 ℃, with a pump through a vacuum for 685 ~ 710 MMHG Cornell homogenizer, can even a removal of steam hose, has particularly good effects.