A type of Grinding Machine that grinds a workpiece plane or a profiled surface.The main types are horizontal axis rectangular table, horizontal axis round table, vertical axis rectangular table, vertical axis round table and various special surface grinders. Surface Grinder,Surface Grinding Machine,Grinding Machine,Surface Grinder For Sale,Application of Surface Grinder,Surface Grinding With Good Price Jiangsu Hoston Machine Tools Co., Ltd. , https://www.hosdunmachinetools.com
â‘ Horizontal axis table surface grinder
The workpiece is held by a rectangular electromagnetic table or clamped on the table and reciprocated longitudinally.
The wheel frame can be used for lateral intermittent feed movement along the dovetail guide of the slide. The sliding seat can be vertically intermittently fed along the guide rail of the column, and the workpiece is ground by the grinding wheel, and the grinding precision is high.
â‘¡ Vertical shaft round table surface grinder
The vertically mounted grinding wheel spindle grinds the workpiece with the grinding wheel end face, and the grinding wheel frame can perform intermittent vertical feeding movement along the guide rail of the column.
The workpiece is mounted on a rotating circular table for continuous grinding and high production efficiency.
In order to facilitate the loading and unloading of the workpiece, the circular table can also be moved longitudinally along the bed rail.
â‘¢ Horizontal axis round table surface grinder
Suitable for grinding round sheet workpieces, and can be used to tilt and grind round workpieces with different thickness.
â‘£ Vertical axis rectangular table surface grinder
Since the diameter of the grinding wheel is larger than the width of the table, the grinding area is large, which is suitable for efficient grinding.
⑤ Double end grinding machine
The two parallel planes of the workpiece are simultaneously ground by the grinding wheel end faces of the two grinding heads, and there are two types which are the horizontal shaft and the vertical shaft.
The workpiece is guided through the grinding wheel by a linear or rotary feeding device.
This type of grinding machine is highly efficient and is suitable for mass production of parts such as bearing rings and piston rings.
In addition, there are guide grinding machines for grinding the guide surface of machine tools, and special grinding machines for grinding turbine blade profiles.
Talking about How to Improve Accuracy of Determination of Crude Protein in Feed
The national standard method for the determination of crude protein in feedstuffs uses the Kjeldahl method. Because the operation process is more complicated, improper operation may result in inaccurate test results. Let's talk about matters that should be taken care of in the crude protein detection process. This article describes the use of reagents to determine the content of crude protein in feeds, and we can use a simpler and more convenient method, that is, directly use crude protein analyzer or also known as protein analyzer to determine the protein content of feed. .
1 Crude Protein Detection Sampling Process
Whether sample collection is normative is the basis for the determination of crude protein. Although the sampling method varies with different items, it can generally be divided into the following two types according to the uniform nature of the items.
1.1 Uniformity Articles For homogeneous articles, each small part has the same composition as the entire part, and any part of it can be used as an analytical sample. In normal circumstances, powdered or ground items can be sampled using the "quartet" method.
1.2 Non-homogeneous items of non-uniform items, shall take a large number of samples, and then repeat the sampling of the samples taken a number of times to obtain a series of gradually decreasing the sample, called the primary, secondary, tertiary helium samples. Analytical samples can be prepared in the last sample so that the sample can represent all items. The sampling method used is called "geometry."
2 Crude Protein Testing Crushing Requirements
According to the feed industry standard calibration, the sample is required to pass through a 40-mesh (0.45 mm) sample screen after comminution, and then uniformly mixed in a sealed container. Generally, the feed sample has large particles and complex components. When the sample is weighed, there are few samples. If the fineness is not enough, the samples will inevitably cause unevenness when they are weighed. This is an important reason for the resulting error.
3 crude protein detection requirements
Use an analytical balance to weigh 0.5 to 1 g (accurate to 0.000 1) of the sample in duplicate, requiring that the amount be appropriate at the time of weighing, not too little or too much. The amount of the general feed sample is 0.5 g. If the crude protein content is 3% to 5%, the sample volume should be higher than 0.5 g, otherwise the error will be large.
4 Crude protein assay digestion process
4.1 Digestion temperature and speed The speed of digestion is slow. Start with a small fire. After coking the sample, gradually increase the firepower. If the temperature is increased too quickly, part of the nitrogen-containing substances will not be converted into ammonium sulfate and will be lost in the form of gas, which will result in a low detection result. Note that the black slag spattered on the bottle wall is often shaken into the bottom sulfuric acid solution to avoid incomplete digestion. To control the temperature during digestion, the optimum temperature is 380 °C. If it is too low, the digestion time is long and the digestion is incomplete. Therefore, it is best to use an adjustable electric stove for digestion.
4.2 Attention When digesting, add a few glass beads to the Kjeldahl bottle to prevent loss of sulfuric acid. A small funnel is placed on the Kjeldahl flask to allow steam to condense back. This will make the determination more accurate. When the digestive fluid reaches a transparent state, it does not mean that the sample has been completely digested. In order to prevent the result from being low, it must be heated and digested for at least 2 hours.
5 crude protein detection distillation process
During the distillation process, it must be ensured that the system is closed. After the sample solution is added to the distillation apparatus, the inlet glass stopper should be plugged and sealed with distilled water at the inlet, and then the alkali solution should be added. The addition should be slow and not too fast. After the addition of the alkali solution, the inlet glass stopper cannot be opened again. This order can not be mistaken, otherwise it will cause ammonia loss, so that the measurement results are low.
6 Titration procedure for crude protein detection
The concentration of hydrochloric acid standard solution for titration must be accurate. Before using the standard solution, the solvent bottle should be shaken up and down several times in order to completely dissolve the water droplets that condense on the bottle wall into the solution to ensure the uniform concentration of the solution. During titration, the air bubbles at the bottom of the burette should be excluded to ensure accurate titration results.
7 Crude Protein Detection Makes Blank Inspection Work
Blank measurement is a very important comprehensive indicator to measure the entire operation process. A good blank value is the premise to ensure the accuracy of the test results. The blank value cannot exceed the standard range. If you find that the blank value is too high during the test, you should carefully search for the cause and solve it in time. Excessive blank values ​​are generally due to insufficient reagent levels, impure test water, or unclean glassware.
8 Crude protein detection self-verification
The Kjeldahl airtightness should be regularly checked. Verification method: In order to use analytical ammonium sulfate instead of the sample, according to the test procedure of the sample, the nitrogen content should be measured to be 21.19% ±012%. If the result is inconsistent, the sample should be checked for weight loss, digestion, alkali addition, distillation and titration. Is each step correct?