In order to fully implement the food distribution system reform policy, timely grasp the changes in grain and oil storage quality, timely promote storage, and accurately define the aged grain and oil, according to the requirements of the 5 grain and oil storage quality determination rule 6 of the National Grain [1999] No. 148, the central reserve of rice The main grain and oil varieties, such as wheat and wheat, should be tested regularly (usually twice a year) for their storage quality indicators. Related recommendation: rice mill DSX PV Support Connector,PV Connector,Photovoltaic And Aluminum Wuqiang Xingdou International Trade Co., Ltd , https://www.xdaluminumproducts.com
However, in the actual inspection work, there are inconveniences caused to the daily inspection work due to equipment reasons. For example, most of the electric grinders equipped in laboratories are of the FSF type, and it is difficult to achieve the required sample fineness in the inspection. degree.
The FSF crusher is equipped with copper screens with sizes of <1.0, <1.5, <2.0 mm, with a large crushing size, and the preparation of samples with a fineness of 40 mesh / 2.54 cm is a laborious, time consuming, and time-consuming process. Inefficient work. Take the sample of wheat viscosity as an example. The process of preparation according to the national standard method is: crushing and sifting with a pulverizer, and repeatedly smashing (or grinding with a mortar and pestle) over 90% of the sample through 60 mesh / 2.54cm Sieve 0, it takes about 2 hours to prepare such a sample. Similarly, preparation of test wheat gluten sample (over 95% through 40 mesh / 2.54cm sieve), generally also need about 115h, while wheat gluten content determination is a routine inspection item required in grain and oil trade. Therefore, the problems presented by sample preparation have become bottlenecks in the inspection of these projects, and have caused inconvenience to practical inspections. As a result, many grass-roots units that have not yet been equipped with cyclone mills for economic reasons find it difficult to do so. Unable to implement.
In order to enable these inspection projects to be carried out successfully in laboratories equipped with conventional FSF grinding mills, after long-term exploration and practice, we believe that: some necessary improvements to the FSF grinding mill can meet the inspection requirements, and from Economically, only tens of RMB can be used to solve the problem. The actual results achieved are: When the sample fineness requirements 40 mesh / 2.54cm, retained 40 mesh / 2.54cm sieve 3%, took 9min; sample fineness requirements 60 mesh / 2.54cm, retained 60 mesh / 2.54cm sieve 8%, took 15 minutes. The improved method of FSF type grinding mill is introduced as follows.
1 Equipment and materials FSF grinding mill (electric grinder), commercially available 50 mesh / 2.54cm, 70 mesh / 2.54cm stainless steel mesh, thickness 0125mm thin iron, connection number, tool set, 220V 3A switch one ( Same as original power switch).
2 Adjustment of grinding mill
2.1 knife pitch adjustment (see Figure 1) 
a) Cut off the power supply and pull out the insert on the fixed blade chamber;
b) Loosen the fastening screw in the middle and screw in the push screws on both sides to adjust the cutter distance (ie, the distance between the fixed cutter and the rotary cutter). The clearance between the fixed knife and the rotary knife should be smaller, so as not to touch the knife during rotation.
The author adopted the adjustment is: Precession advance screw, and rotate the motor rotor by hand, until the fixed knife and the knife just touch the knife, and then retreat 1/4 week advance screw, and then fasten the middle fastening screw. After all the adjustments of the fixed knife are completed, turn the rotor by hand to observe the gap between the fixed knife and other adjustments. If the situation is normal, all plugboards are plugged in and the adjustment of the knife distance is completed.
2.2 adjustment of the rotation direction (see Figure 2) 
The direction of rotation is achieved by installing a steering switch. The installation steps are:
a) Uncover the cover on the motor terminal box and remove the connection wire below the terminal box;
b) As shown in Figure 2 below, use a 40cm long four-core cable to make circuit connections and solder the steering switch (pre-wiring the string to the base before connecting);
c) Fix the steering switch and wiring on the motor base. The power switch of the steering switch and the motor should be placed on the two opposite sides of the base. When fixing the steering switch, the fixed position is preferably: When the steering switch is pulled to the left, the rotor of the motor rotates counterclockwise. At this time, the grinding mode is the cutting mode, which is usually referred to as front-front grinding (FF mode). When the steering switch is pulled to the right, the rotor of the motor rotates clockwise. At this time, the grinding method is the grinding method, which is usually called dull-blunt grinding (DD method).
2.3 Screens (see Figure 3)
a) Choose a piece of iron sheet with moderate hardness and moderate rigidity, with a thickness of 0125mm (the author uses a bar of Lulu Beverage). After folding, use a pair of scissors to cut into pieces of iron as shown in Fig. 3 (with the phosphor bronze of the original grinder. The screen size is the same), hollowing out the middle rectangular block, slightly polished, made of screen holder;
b) The 50 mesh / 2.54cm, 70 mesh / 2.54cm stainless steel screens sold will be cut to a width that is slightly less than the size of the screen holder;
c) A 50 mesh/ 2.54 cm or 70 mesh/ 2.54 cm sieve is sandwiched in the middle of the screen holder and then inserted into the screen frame of the FSF type crusher. The requirements for screens are: moderate elasticity, easy disassembly, and close cooperation with screen frames.
3 Sample preparation
3.1 For the preparation of wheat samples with a fineness of 40 mesh/2.54 cm as an example, the preparation steps are as follows:
a) Prepare the crusher, mainly for a 50 mesh / 2.54cm stainless steel screen;
b) Weigh 100g of wheat sample with impurities removed and place it in the hopper of the crusher (2~3 times adding);
c) Turn the steering switch to the left, that is, adopt a front-edge grinding method for cutting and crushing;
d) Turn on the power switch and wait until the operation is normal, then pull out the hopper inlet plate, so that the sample slowly falls into the working room to be crushed (should the smashed material is full of the holding box, it should be cleaned in time);
e) When the sample (including the dropped material) is nearly crushed, that is, when it falls into the studio, close the hopper inlet board and disconnect the power supply;
f) Turn the steering switch to the right and use a blunt-blind method to grind and crush.
g) After the motor stops, turn on the power switch to grind and crush.
h) Finally, the pulverizer is converted to a front-blade operation for about 1 min. The machine is shut down and the pulverized materials are combined and mixed. Finally, the pulverizer is converted into a front-blade method again. Its role is to continue smashing the bran material and determine the crushing method for the preparation of the next sample (if the blunt-blunt method is used before, the last step is mostly Large bran flakes remain in the work room. If you want to crush it finer, it will be relatively difficult.) So far, 100 g wheat sample with a fineness of 40 mesh/2.54 cm has been prepared.
3.2 The preparation of wheat samples with a fineness of 60 mesh / 2.54cm is basically the same as the preparation of a wheat sample with a fineness of 40 mesh / 2.54cm. The differences are:
a) Replace the screen with a 70 mesh/2.54 cm stainless steel screen;
b) Longer time required, preparation of a wheat sample takes 15min;
c) Inconsistent crushing progress, generally faster in the first half and slower in the second half.
With the continuous comminution of wheat samples, the easily-pulverized endosperm part becomes the sieved material first, and the bran material is more difficult to be crushed. Therefore, the difficult-to-pulverize material will slowly accumulate in the working chamber, which will reduce the crushing efficiency and accelerate the crushing. The progress can be appropriately increased in the blunt process blunt - blunt grinding times (usually 1 or 2 times). It is worth noting that when the blunt-blunt method is adopted in the middle, the inlet hopper plate should be closed firstly, and then switched to the blunt-blunt method after 1~2 min, in order to prevent the whole or large grain material from sinking under the shutdown condition. In the studio, it caused the second boot to overload or squeezing or even smashing the screen.
4 Test results A sample of wheat with a fineness of 40 mesh / 2.54cm was prepared. It took less than 10 minutes and passed over 40 mesh / 2.54cm (CQ16) sieves in excess of 95%, and most of the retained material was thin and clean. For bran flakes, the gluten content of the sample prepared by this method was measured. The error of the parallel test was small and the result was accurate and reliable. Prepare a sample of wheat with a fineness of 60 mesh / 2.54cm. It took 15 minutes to pass through 60 meshes / 2.54 cm sieves exceeding 90%, leaving 60 meshes / 2.54 cm sieves generally 6%-9%. The samples prepared by this method were tested for viscosity and the results were very satisfactory. Using this method to prepare 60 mesh / 2.54cm fineness rice samples, the better the crushing effect, almost all passed and the short time, the viscosity test, the effect is very good.
5 Description of the problem in use
5.1 The adjusted FSF crusher does not need to re-adjust the knife pitch when performing other fineness sample preparation. After tests, the screen was changed to the original configuration of <1.0mm or <1.5mm of phosphor bronze screen, the crushed particle size is relatively fine, slightly faster, no effect on the service life.
5.2 The screen holder and the screen frame should be firmly fixed so as to prevent the high-speed rotating material from pushing out of the screen frame of the pulverizer and causing failure.
5.3 When the pulverizer performs the front-blade and blunt-blind methods, it must turn off the power switch first. After the motor stops, it will perform steering switch and start. Otherwise, it will switch directly under high-speed rotation of the motor. The rotation of the rotor of the motor will not change and the steering switching effect will not be achieved.
5.4 If a stainless steel screen is not available, it can be replaced by a copper screen of the same type. When using a copper screen, the screen holder can be made of a single layer but the thickness of the sheet should be changed to 0.5mm, and the screen directly with a soldering iron. Welding on. The effect is also good when used, but the problem is: the strength of the copper mesh is relatively small, and when the raw grain is directly crushed, the copper mesh screen is easy to break or deform. The improvement measure is that it can be first smashed with <1.0 mm phosphor bronze sieve, and after grading by 40 mesh/ 2.54 cm or 60 mesh/ 2.54 cm sieve, the sifted sieve residue is smashed with copper mesh, and its The effect is very good and not much time-consuming.
Conditional units can be crushed using two pulverizers, one for pre-crushing and one for secondary pulverization, so that flow-through work is performed to prepare 60 mesh/2.54 cm fineness samples. The time required for the single crushing process will be shortened.