RCrider

Enviar mensaje

Anuncios

Implications, advantages and disadvantages of PDC compacts _ BITs

Descripción: Original title: Meaning, advantages and disadvantages of PDC compact PDC, also known as Polycrystalline Diamond Compact, is widely used in the field of geological drilling and oil drilling because of its excellent abrasion resistance and impact resistance. Today, Sidi Xiaobian shares with you the knowledge of dry goods related to PDC composites. Let's go with Xiaobian to see the advantages and disadvantages of PDC composites and make better use of them. PDC compact is a new type of functional material, which is a composite superhard material sintered by diamond powder and hard alloy substrate under the condition of ultra-high pressure and high temperature. It not only has the high hardness, wear resistance and thermal conductivity of diamond, but also has the strength and impact toughness of hard alloy. It is an excellent cutting tool and wear-resistant tool material. It has been widely used in many fields such as metal and non-metal cutting tools, wood processing tools, oil and gas drilling bits and so on. In geological drilling, coalfield drilling and oil and gas drilling, PDC compact bit has become one of the most commonly used rock breaking tools because of its excellent rock cutting speed and long service life. Let's take a look at the advantages of PDC bits: 1. The force balance design makes the drill bit have good guidance, which is suitable for directional drilling with downhole motor and has small radial vibration; 2. The reasonable arrangement of the patented PDC compacts with different structures at different positions of the drill bit makes the drill bit have strong aggressiveness and abrasion resistance; 3. Strong aggressive design can make the bit obtain higher penetration rate; 4, the drilling capacity in the rock stratum is 10-30 times of that of a common alloy drill bit, and the operation efficiency is improved; 5. Because the material of PDC bit is mainly cast tungsten carbide and diamond compact, it has long service life and high value. At the same time, down the hole bit , the PDC bit also has its indispensable shortcomings, and the conventional PDC bit has several shortcomings: 1. Due to the large difference of linear expansion coefficients between polycrystalline diamond and cemented carbide, the thermodynamic characteristics of the interface between polycrystalline diamond and cemented carbide are not well matched, and there is a large residual thermal stress, which easily leads to the delamination of diamond and tungsten carbide; 2. The surface of PDC is mostly flat. In order to reduce the chip adhesion phenomenon and the number of quality inspections, it is generally polished into a mirror surface to improve the surface finish, but the cost is high and the anti-sticking effect is not obvious; 3. With the continuous wear of the working edge of the PDC bit, its surface forms a plane or arc surface, and the contact area with the rock increases sharply, resulting in a sharp drop in rock pressure, a decrease in rock breaking speed, and an increase in wear, especially for deep and ultra-deep drilling, frequent replacement of the bit will increase the drilling cycle and drilling costs. The PDC compact developed and produced by Sidi has stronger compression resistance, excellent rock breaking ability, excellent grinding resistance and impact resistance. It adopts the latest synthetic technology to make its service life longer, more aggressive and more resistant to high temperature. It can effectively maintain its original characteristics in high temperature environment and greatly improve the efficiency of drilling for customers. PDC compact is a product developed to meet the drilling needs of complex formations, which is mainly suitable for oil and gas drilling under harsh geological conditions. SIDI PDC uses high-quality diamond, cemented carbide and other raw materials, and adopts advanced synthesis technology. Its product combines the advantages of diamond and cemented carbide,rock drilling tools, which not only has extremely high wear resistance, but also has good impact resistance and thermal stability, which greatly improves the drilling speed in hard rock drilling. Return to Sohu to see more Responsible Editor:. wt-dthtools.com

Fecha de Publicación: 08-11-22

What are the types of rotary drilling bits? _ Bedrock

Descripción: Original title: What are the types of rotary drilling bits? Introduction of rotary drill bit manufacturer on classification of rotary drill bits: Common rotary drill bits include auger bits, rotary buckets, barrel core bits, underreamer bits, percussive bits, percussive grab cone bits and hydraulic grab buckets 1. Auger bit (1) Conical: double head double screw,overburden drilling systems, suitable for hard bedrock. Double-headed single screw, suitable for weathered bedrock, pebbles,dth rock bit, frozen soil with ice, etc. The above drill bits are equipped with various picks, and many types of drill bits can be derived through the changes of tooth type, pitch and helix angle. (2) Straight screw bit: a. Bucket tooth straight screw: double-head double-screw, Tapered Rock Bit ,mining dth bit, suitable for sandy soil, small-diameter gravel layer with poor cementation; double-head single-screw ? Suitable for sandy soil and soil layer; single head and single screw ? Suitable for large diameter pebbles, cohesive soil and hard mastic with poor cementation. B. Pick straight screw: double screw, triple screw and quadruple screw, suitable for hard bedrock or gravel. The bucket is applicable to a wide range of strata. The single-layer bottom is only applicable to the soil layer with strong viscosity. The double-door drilling bucket is applicable to a wide range of strata. The single-door drilling bucket is only applicable to large-diameter pebbles and hard clay. II. Rotary drilling bucket can be divided into pick drilling bucket and bucket tooth drilling bucket according to the teeth installed; and can be divided into double-layer bottom bucket and single-layer bottom bucket according to the number of bottom plates. According to the number of doors, it can be divided into double door buckets and single door buckets. According to the taper of the barrel, it can be divided into conical barrel drilling bucket and straight barrel drilling bucket. According to the shape of the low plate, it can be divided into pot bottom drilling bucket and flat-bottomed drilling bucket. 。 The above structural forms are combined with each other, and with the change of whether to have a vent hole and a door opening mechanism, dozens of rotary drilling buckets can be combined. Generally speaking, double bottom drill III. Barrel type coring bit At present, there are two common ones: cutter barrel drill (suitable for medium hard bedrock and gravel) and roller barrel drill with high drilling efficiency. The difference of coring device mainly depends on the difficulty of coring. Because the roller core bit is mainly used for hard rock drilling, and the annular area of drilling is large, if conditions permit, reverse circulation drilling can be added to the bit part to lift (applicable to hard bedrock and large boulders). In the two types of drill bits of barrel coring drill, there are also coring devices and non-coring devices. IV. Reaming drill bit In order to improve the bearing capacity of single pile on the basis of no increase of pile diameter and pile depth, the design department often uses belled pile to realize the hard bedrock of rotary drilling rig. Because the rotary drilling is a non-circulation drilling,dth hammer bit, the slag can be removed with a slag removal bucket after the bottom expansion is completed. Bottom drill bit is enough. The commonly used reaming bit is mainly mechanical. This kind of bit is relatively simple to use and maintain. It has an upper opening type and a lower opening type. The opening mechanism is generally a four-link mechanism. It can be used for soil, strong wind, moderately weathered strata and even construction reaming without any change. You only need to select the reaming back to Sohu to see more. Responsible Editor:. wt-dthtools.com

Fecha de Publicación: 08-11-22

Ailan Island National Service: Novice Introduction to the use of basic mineral resources and access! _ Flint

Descripción: Original title: Ailan Island National Service: Novice Introduction to the game of the use of basic mineral resources and access! In the process of survival exploration in the game "Island of Aylan", most of the operations are carried out around the exploitation and utilization of mineral resources. For example, the activities of the birth island should develop science and technology through the acquisition of mineral resources to ensure a safer living space. Sea exploration is a choice based on the non-renewability of mineral resources. Therefore, if we want to play this game well, we must understand the use of mineral resources and the way to obtain them. As in the real world, the mineral resources in the game of Island Island are divided into three categories, namely, non-metallic minerals, such as flint, clay, saltpeter, sulfur, crystal, etc.; metal minerals, such as iron ore, copper ore, gold ore; and combustible organic minerals, coal. Next,Borehole Drill Bits, we will introduce the acquisition and use of these minerals. 1. Flint Flint is mainly used for ignition, and two flints can be combined into a flint igniter. You can make burning torches, and you can also light all the items and equipment that need to be lit, such as bonfires, smelting furnaces and so on. Flint can be seen everywhere in the game, and there are many flint veins on the surface besides scattered individual flints. Obtaining is very simple. Because flint igniters can be repaired when their durability is reduced, flint mines do not need to be mined too much. Expand the full text 2. Clay Clay was an essential mineral into the Iron Age. At the stage of entering the Iron Age,mining dth bit, a large amount of clay was needed to build smelting furnaces, charcoal kilns, forging platforms and other equipment to smelt and process iron ore and copper ore. So technology can't get off the ground without clay. In addition, clay is also the raw material of brick structure, players who like to build can accumulate more, clay is widely distributed in the game, and the difficulty of mining is relatively low. 3. Thick saltpeter block and thick sulfur block Mononitrate, disulfonic acid and charcoal. Saltpeter is the main raw material for making gunpowder. In the Iron Age, gunpowder could be made with saltpeter and sulfur, and hot weapons, such as pistols, rifles, cannons and grenades, mining drill bit ,fastest dth hammer, began to be used. And then enhance the combat effectiveness of the role, maintain a safe living environment, with firearms, with the flying backpack, players will be able to access the hole more safely, access to more advanced resources. In addition, some equipment and tools in the later period need to use rubber, and sulfur is also one of the materials for making rubber. Thick saltpeter blocks and thick sulfur blocks are relatively rare minerals, which are not distributed much in the game. If you see them, you must collect them all. In addition, there are NPC merchants on some islands. If you meet them, you can exchange a large amount of saltpeter and sulfur, which is also the main source of thick saltpeter and sulfur blocks. 4. Coal Coal is the main industrial fuel in the game of Island Island, and coal is used in the smelting and processing equipment of ore. Later in the game, materials such as steel plates, steel pipes and steel poles are needed. The raw materials of these materials are iron ingots and coal. 5. Iron ore and copper ore These two minerals are the most distributed in the game and the most used metal minerals. When used, it needs to be smelted into iron ingots and copper ingots. Iron ingot is not only the material for making basic ironware, but also the important raw material for making advanced industrial materials such as steel plate and steel pole. It will be used when science and technology enter the Iron Age until the later period. Copper ingot is an important material for energy equipment, which needs to be processed into copper wire before it can be made into important components of energy equipment. In addition, iron and copper ingots are also important materials for making bullets. 6. Gold mine Gold mine is the scarcest mineral in the game of Island Island. It is only distributed in a small number of holes in the ground, but its demand is not too large. The most important use in the later period is to make a guard suit, which is the top armor in the exploration mode. Gold is scarce, but it is not too difficult to obtain. There are two main ways to get, first, open the game randomly appear in the high-level box, there is a great chance to burst out gold or golden pebbles; second, through the game NPC merchants exchange golden pebbles. And then use a smelting furnace to smelt that golden pebbles into gold ingot. 7. Aylan Uranium Dust Aylan uranium dust is the main material for making advanced equipment, such as flying backpacks, mining drills, Aylan uranium batteries, charging stations and so on. These tools and devices can greatly improve the level of technological development in the game. Therefore, the importance of Aylan uranium dust is self-evident. There are three main ways to obtain Aylan uranium dust. First, kill mutant animals in the hole and drop them; second, collect Aylan Uranium Crystal from the hole, and then use the Aylan Uranium Refinery to extract Aylan uranium dust; third, there is a chance to get Aylan uranium dust by opening the advanced box. These are the main mineral resources in the game, each of which is a non-renewable resource. It is suggested that every island should be carefully searched, except flint, all other minerals need to be mined and collected, not wasted. In addition, in order to improve the mining efficiency of minerals,dth button bits, flying backpacks and mining drills can be made as early as possible. With the help of flying backpack, you can get the maximum game vision, which is conducive to finding mineral distribution and exploring deep underground caves. The mining drill can greatly increase the mining efficiency and speed up the game. That's all for today's basic strategy. Return to Sohu to see more. Responsible Editor:. wt-dthtools.com

Fecha de Publicación: 08-11-22

Design and Construction Organization Plan of Lightning Protection Engineering (I) _ Grounding

Descripción: Original Title: Lightning Protection Engineering Design and Construction Organization Plan (I) The lightning protection project needs to be implemented in an organized and step-by-step manner to ensure the quality and duration of the project. Today, Junhe Electronics takes a project as an example to share with you the template of lightning protection engineering design and construction organization scheme for reference only, as follows: I. Lightning protection design scheme 1. Project overview The project is located in XX Town, XX County, XX Province, which is surrounded by mountains on three sides. The project is located in the south of the XX fault zone. There are few soil layers in the project yard, no vegetation, mostly rocky mountains, and the soil resistivity is high. The available land area around the building is small, there is no vegetation soil layer, and it is mainly rock. The measured soil layer is 1420 Ω · m (the surface layer is backfill soil), and the grounding coefficient varies with the season. The measured soil resistivity of highly weathered dolomite in L201 and L202 buildings is 20000 ohm · m. 2. Analysis of design scheme There are many grounding methods for lightning protection, such as (1. Soil replacement method, 2. Artificial soil treatment method (chemical treatment of soil), 3. Deep buried grounding electrode method, 4. Multi-branch external grounding device method, 5. Grounding module grounding method, 6. Sewage introduction method, 7. Deep well grounding method). There are two grounding methods suitable for L201 and L202; Deep well grounding method and grounding module grounding method. Disadvantages of grounding method of grounding module: Due to the shallow soil layer of the project site, the geographical environment changes significantly in four seasons, and the rainfall is not balanced, which objectively causes the instability of soil temperature, humidity and water retention, and will affect the stability of the resistance of the whole ground network. It destroys the geological structure, occupies a large area, and the land used becomes dead and can not be reused. The service life of the module is short, the material composition is complex, ranging from several hundred yuan to several thousand yuan, and the module itself is fragile, which will affect the instability of the resistance value. The distance between the grounding grid of the lightning tower and the grounding grid of the building foundation is too close, which may lead to the formation of ground potential counterattack, resulting in serious consequences such as equipment damage. Module grounding needs to change the soil, but it is difficult for us to get the soil, and it also depends on what kind of soil (sandy soil, loess, black soil) will affect the resistance. The modules are connected by flat steel, which is easy to corrode and also affects the resistance. The extensive use of common resistance reducing agents has an impact on groundwater and soil quality, which is related to personal health and safety! In terms of price comparison, if better materials are used and products meet the requirements of national standards, the price difference between deep well grounding and deep well grounding is not very large. Advantages of deep well grounding method: The deep well grounding mode eliminates the influence of temperature difference in four seasons and ensures the stability of grounding grid resistance. It occupies a small area and will not affect the land use. The use of long-acting physical resistance reducing agent, green environmental protection, pollution-free, long life, in line with the standards of the national testing department, the first phase of the project experience can be verified. The ion grounding electrode has the advantages of high conductivity, long service life and stability. All the connections are made by copper wires, so the corrosion degree is low, the resistance is small and the resistance value is stable. Expand the full text Based on the above analysis, the comprehensive grounding scheme based on deep well grounding is the most effective, economical and practical grounding scheme. 3. Design basis The main contents of the current relevant specifications, regulations and acceptance standards for installation works issued by the People's Republic of China are as follows: Design Code for Protection of Structures against Lightning GB50057-2010 Technical Code for Protection against Lightning of Building Electronic Information System GB50343-2012 Installation Drawings of Lightning Protection Facilities for Buildings 99 D501-1 Code for Design Review and Completion Acceptance of Lightning Protection Devices (Order No.21 of the State Meteorological Administration) Design Code for Lightning Protection and Grounding Engineering of Communication Bureaus (Stations) YD 5098-2005 Standard for Grounding of AC Electrical Installations DL/T621-1997 According to the geotechnical investigation report of Gaoxin Phase III, it is shown as follows: The first layer: artificial fill: mainly composed of clayey silt, containing plant roots and organic matter, located on the artificially reclaimed slope, with a thickness of 0.3 ~ 1.5m. Layer 2: loessial clayey silt and silty clay of Quaternary Upper Pleistocene eluvium, alluvium and diluvium, slightly wet-wet, slightly dense-medium dense, with developed voids, containing a small amount of gravel and plant roots. The thickness of this layer is 0.5 ~ 3.5m. Layer 3: strongly weathered dolomite Layer 4: Moderately weathered dolomite Layer 5: Weathered dolomite According to the geological conditions of the test site, the geological environment of the grounding grid is poor and the soil resistivity is high. According to the design requirements of the test area, the grounding resistance of L201 and L202 buildings is less than 1 Ω. If each building is made separately to meet the design requirements, not only the layout and working surface of the site can not meet the construction requirements, but also the investment is very huge, resulting in the waste of repeated construction and investment. Considering the technical feasibility and rationality and avoiding the waste of investment, we suggest that several buildings should share the grounding network, and the resistance value should be less than 1Ω according to the minimum value of the design requirements of several buildings,dhd drill bit, which can meet the original design requirements. Technical analysis Based on the above requirement of joint grounding, the power frequency grounding resistance of the grounding grid is R ≤ 1Ω, and the theoretical calculation of the grounding resistance of the whole grounding grid in this project is as follows: Calculation of vertical grounding resistance: According to the geotechnical engineering investigation report, the first layer (0-1.5m) of the site and its vicinity is artificial fill, and the soil resistivity distribution is about 350-600Ω · m; the second layer (1.5-5m) is loess-like silty clay and heavy silty clay, containing a small amount of sand and stone, and the soil resistivity distribution is about 800-1300Ω · m; The third layer (5-9.4m) is mostly strongly weathered white rock layer and moderately weathered white rock layer, and the soil resistivity distribution is about 1600-2100Ω · m; the fourth layer (9.4-120m) is slightly weathered white stone layer, and the soil resistivity distribution is about 2400-3800Ω · m. According to the geological survey report, there is no water layer at 100m, and there is a 120m deep well in the plant area. Assuming that there is a water layer below 120m, the soil resistivity distribution is about 20-70 Ω · m. The layering calculation formula shall be in accordance with DL/T621-1997 Standard for Grounding of AC Electrical Installations; According to the calculation, the horizontal grounding resistance in the grounding grid is RO = 1. 56 Ω. When the resistance reducing agent is added around the horizontal connecting copper wire, the average resistivity of the soil can be reduced, and the resistance reducing rate is 0. 2. At this time, the horizontal grounding resistance in the joint grounding grid is RO = 1. 25 Ω. Calculation of compound grounding resistance After comprehensively considering the combination of deep well grounding electrode and horizontal connection copper wire, its grounding resistance shall be calculated according to DL/T621-1997 Standard for Grounding of AC Electrical Installations: after the combination of deep well grounding electrode and copper wire, the grounding resistance of the combined grounding network of 6 deep wells Rx = 0.74Ω Conclusion According to the above design method, the power frequency grounding resistance of the joint grounding grid is less than 1Ω, which meets the engineering requirements of Party A. Similarly, according to the formula, a 130m (according to the geographical situation, the drilling depth should reach more than 15m after the visible water layer, so the depth should be determined according to the actual situation) grounding deep well is drilled between the two towers (see the construction drawing) at the lightning tower of L201 and L202 buildings,dth drilling hammer, which is the common grounding well of the two lightning towers. The theoretical prediction can meet the design requirement that the impulse resistance is less than or equal to 10Ω, and if the requirement cannot be met, two nearby deep wells can be jointly grounded. (According to 4, 2 and 1 of Code for Design of Lightning Protection of Buildings GB50057-2010, independent lightning rod, overhead lightning wire or overhead lightning network shall be equipped with independent lightning device, and the impulse grounding resistance of each downlead shall not be greater than 10Ω. In areas with high soil resistivity, the impulse grounding resistance can be increased appropriately, but in areas below 3000Ω m, the impulse grounding resistance should not be greater than 30Ω. Because the geological survey report States that water can be seen below about 100 meters, the value used in the formula is 120 meters. 4. Design quantity According to the calculation of grounding resistance of deep wells, it is necessary to drill 6 grounding deep wells (about 130 meters each) between buildings in parallel to meet the design resistance requirements. The deep well is connected to the grounding grid of the building by 95mm2 copper wire brazing. A total of 18 KS-JD-3000 ion grounding electrodes (3 for each well), 1518.5 meters of 95mm2 copper wire connecting line and 32.17 tons of resistance reducing agent are required for construction. A total of 18 KS-JD-3000 ion grounding electrodes, 1518.5 meters of 95mm2 copper wire and 32.17 tons of resistance reducing agent are required for construction. The above design is calculated according to the theoretical value. In case of deviation between the grounding resistance value and the calculated value due to the change of geological conditions in the construction practice, the grounding unit of the deep well shall be increased or decreased according to the measured value. Until the resistance value required by the project is reached. 5． Construction scheme and main subdivisional construction methods (1) General principle of construction Reasonable arrangement of working procedures, close connection of working procedures, scientific and standardized management, and full utilization of man and machine (2) Construction scheme Excellent construction personnel shall be selected to organize the construction meticulously. During the construction, parallel crossing and flow operation shall be adopted to optimize the working procedures so as to ensure the overall construction period. Pay attention to safe construction to avoid personal injury and property loss. Strengthen the management of key sub-items, take the overall situation into account and manage scientifically. (3) Construction process Surveying, positioning and setting out shall be carried out in combination with the site and drawing dimensions to excavate the trench of the grounding grid, install the well drilling equipment, drill the well, bury the grounding electrode, grout the deep well, connect the grounding grid and reduce the resistance of the grounding grid for backfilling. (4) Construction technology Dig a trench Excavate the grounding grid trench. Excavate the grounding grid connection trench according to the drawing. The width of the upper part of the trench is 1000 mm, the bottom of the trench is 1000 mm, and the depth of the groove is 800 mm. Punch Because of the complexity of the formation, the combined drilling method of mud positive circulation and air Dth hammer is adopted. According to the geological survey report, the thickness of strata 1 ~ 5 is 5 to 10 meters, the original soil layer is silty clay with broken stones, and the broken fissures in the strongly and moderately weathered section are filled with clay. The process adopts Ф219 mm bit mud positive circulation rotary drilling, and in case of formation collapse, the casing is lowered to protect the hole. Air Dth hammer was used to drill the No.6 formation. Features of Dth hammer (air hammer): Air drilling is one of the most popular drilling methods in the world. As a new drilling tool in air drilling, Dth hammer has great application prospects. 1) less gas consumption; 2) that structure is simple, the reliability is high, and the requirement of various pressure conditions are met; 3) The optimized design of the patented technology system can maximize the use of the energy of the air compressor; 4) The hammer teeth of the new air hammer effectively alleviate the wear and fracture of the hammer teeth and greatly improve the pure drilling time; 5) High-hardness metal on the outer layer of bit teeth: compact, hard and wear-resistant; strong and tough metal on the inner layer : Good toughness, impact resistance, not easy to break. Dth hammer is also called pneumatic hammer, which uses compressed air as power medium to complete percussive rotary drilling and has the characteristics of air flushing drilling. Compared with the percussive rotary drilling with high-pressure water or mud as the power medium, the pneumatic Dth hammer rotary drilling has double efficiency. Important link of pore-forming 1) Overburden drilling A carbide bit was used for rotary drilling and the φ219 mm iron casing pipe was lowered. The key to the hole forming process of this project is to seal the gap between the protective pipe and the orifice tightly, especially in loose gravel strata, this step is particularly important. 2) Rock drilling Vibrating down-the-hole hammer is used for drilling, which is characterized by no coring, dth drill bits ,Mining Drilling Equipment, complete crushing of the hole bottom, large amount of cuttings, and all of them are carried out of the hole by high-speed airflow. 3) Axial pressure (weight on bit) According to the principle of rock breaking by Dth hammer, rock is mainly broken under the action of impact dynamic load, so the drilling efficiency of Dth hammer mainly depends on the size of impact energy and the number of impact frequency. The axial pressure is used to overcome the upward pushing force generated in the cylinder when the impactor pushes the piston downward, so as to ensure that the impact energy is effectively transmitted to the drill bit. Generally, the weight on bit is 1.3-1.6T. 4) Drilling speed The drilling speed of the drilling tool is mainly determined according to the nature of the rock, the diameter of the bit, the impact energy and the impact frequency. The reasonable rotation speed shall ensure that the rock is broken within the optimal impact gap. Generally, the diameter of the borehole is about 200mm, 30-50r/min for soft strata, 20-40r/min for medium hard strata, and 10-30r/minute for hard strata. 5) Air supply volume During Dth hammer drilling, the compressed air has two functions: one is to provide energy for the movement of the impactor piston; the other is to carry cuttings and cool the drill bit. Therefore, the amount of air supply is determined on the one hand according to the amount of air consumption required by the Dth hammer used, and on the other hand to ensure the upward return air speed of the annular space of the drill pipe. Drilling air supply: It is mainly related to the annular clearance between the drill pipe and the hole wall. Q≥VK60(D2-d2)∏/4 Q-air supply, m3/min D-aperture, m D-diameter of drill pipe, m V-upward return wind speed, generally V ≥ 15m/s K-coefficient, generally about 1.3. In order to make full use of the air compressor, the annular clearance between the drill pipe and the hole wall should be reduced as much as possible. The hole diameter shall be reduced as much as possible under the condition that the installation of pumping equipment is satisfied. In addition, increasing the outer diameter of the drill pipe is also an effective way to reduce the annular clearance. 6) Wind pressure In the process of Dth hammer drilling, the pressure of the air compressor is the sum of various pressure losses in the whole compressed air flow channel. When the Dth hammer drills in the dry hole section, the air supply pressure is the sum of the working pressure of the Dth hammer and the pipeline pressure loss. When there is water in the hole, it is mainly determined by the depth of the hole, the buried depth of the water level in the hole and the water yield. Generally, when there is water, the air supply pressure is about 1.3 times of the hole depth (100m hole depth is 1MPa). Burying of grounding electrode For well entry operation, according to the design drawings, there are three grounding electrodes in each well, 95mm ² copper wire is used for welding between the grounding electrodes, anti-corrosion treatment is carried out for the welding spots, the grounding electrodes are placed section by section to the required depth, and the wellhead is positioned and fastened; High conductivity: Under the same grounding area, the grounding efficiency is 60 times that of the traditional method. Theory and practice show that the resistance in a very small range around the grounding body accounts for 90% of the overall grounding resistance in a uniform soil environment. The mix ratio of that filler material ensure that the resistivity of the filler material is extremely low, and the filler material can effectively permeate into the surrounding soil, thereby greatly improve the resistivity of the surrounding soil. On the other hand, the filler can penetrate into the surrounding soil and form a root-shaped diffusion structure, which greatly increases the effective contact area between the grounding body and the ground and reduces the grounding resistance. At the same time, the vertical grounding mode also effectively reduces the grounding resistance. Long-term effect: Experimental data analysis shows that the effective service life of the product can reach 50 years. The combination of the filler formula and the metal material of the rod body enables the surface of the metal rod body to form a conductive anticorrosive protective film, thereby preventing the corrosion of metal. The unique active ion automatic replenishment mechanism keeps the active ion content in the soil stable, thus maintaining low grounding resistance. The unique process measures ensure that the connection point of the grounding system realizes the true meaning of anti-corrosion. Stability: The product has high stability and is not affected by seasonal factors such as temperature, soil moisture content and the like. Small floor area: the floor area of each grounding unit is less than 0.1m2. It is especially suitable for use in urban grounding construction with dense buildings, and can be used as both an independent grounding body and an additional auxiliary grounding electrode. (4) Grouting During the grouting operation, the mixed resistance reducing agent is injected into the bottom of the deep well through the grouting pump and the conduit, so that the accumulated water in the deep well can be discharged. If necessary, the wellhead can be sealed with anchoring cement, and the high-pressure grouting pump can be used to force grouting into the well, so that the resistance reducing agent can penetrate into the soil along the rock and soil crevices, and the resistance reducing agent in the deep well can be poured compactly until the thick slurry of the friction reducing agent gushes out. (5) Grounding grid welding For grounding grid connection, the formed grounding deep well shall be electrically connected with 95 mm ² copper wire by means of hot melt welding. The welding length shall not be less than 80 mm. The welding seam shall be full and have sufficient mechanical strength. There shall be no slag inclusion, undercut, crack, false welding, air hole and other defects. After the coating at the welding position is knocked clean, it shall be brushed with asphalt for anti-corrosion treatment. When the ground grid is less than 3m away from the entrance and exit of the building or crossing the road during connection, the method of pressure equalizing belt shall be adopted or a gravel layer with a thickness of 150mm shall be laid on the resistance reducing agent, and its width shall not exceed 2m. (6) Resistance reduction of horizontal grounding grid For resistance reduction of the grounding grid, the resistance reducing agent of 30 kg/m shall be poured into the excavated trench, and the resistance reducing agent shall be mixed with water to form a paste, which shall be poured into the trench to wrap the copper wire, and then filled with fine soil and tamped. The trench of the whole project is about 1871 meters long. According to the dosage of 30 kg/m of resistance reducing agent, 28 tons of resistance reducing agent are needed. For backfilling construction, all excavated parts shall be backfilled with original soil, and the soil with high resistivity (sandy soil, stony soil, etc.) shall be replaced with swamp soil, black soil and garden soil for backfilling, and gravel layer shall be added when crossing with roads and pipelines. Principle of long-acting physical resistance reducing agent Physical resistance-reducing agent (also known as long-acting resistance-reducing agent) is made of macromolecular water-absorbing material and electronic conductive material, which contains fine graphite, bentonite, curing agent, lubricant, conductive cement, etc. It is non-toxic, odorless, non-corrosive, and will not pollute underground water sources, and meets the national environmental standards for high-quality soil. This is particularly important because many grounding constructions require well drilling operations and permeable layers. When the physical resistance reducing agent is used, no chemical reaction occurs and no new substance is produced. But only depends on the powdery structure and good conductivity of the resistance reducing agent itself to produce an auxiliary resistance reducing effect on other grounding bodies of the grounding grid. Its principle of action is equivalent to expanding the grounding area of other grounding bodies and increasing the current flow surface. Thereby reducing the contact resistance thereof. In addition, due to the corrosion resistance of the material of the physical resistance reducing agent, the use of the physical resistance reducing agent to wrap other metal grounding bodies is also a protection for the metal grounding bodies. Physical properties of resistance reducing agent 1. It is completely a physical resistance reducing agent, which eliminates corrosive electrolyte, and uses non-electrolyte carbon powder as conductive material to improve the corrosion resistance of metal electrodes. 2, the conductivity is not affected by acid, alkali, salt, temperature, humidity and other changes, with good moisture absorption, heat preservation, anti-freezing function. And 3, the grounding resistance value of the grounding grid can be reduced, the resistance reduction rate can reach 50 to 90%, the soil resistivity can be improved for a long time, and the grounding resistance value is stable. 4. Insoluble good conductor, which will not reduce the conductivity due to the decline of groundwater level or drought, nor will it be lost due to excessive rainwater. 5. Good voltage equalization can improve the potential distribution, thereby reducing the step voltage and protecting personal safety. 6, high temperature and cold resistance, high pressure impact resistance, long-term stability and effectiveness, service life of more than 50 years. 7. Under normal conditions, it is light black solid powder, non-toxic, odorless and pollution-free. The specific gravity of the dry powder is 0.85-0.95, and the fineness of the dry powder is less than 200 meshes. 8. Strong water absorption and thermal insulation performance can keep the soil around the electrode moist for a long time, which greatly reduces the contact resistance between the grounding electrode and the soil. 9. Good permeability, through the infiltration to the surrounding soil and rock crevices, forming a root network, forming a gently changing low resistance drop area around the grounding electrode. 10. The solidified resistance reducing agent is weakly alkaline, surrounds the electrode, has a compact structure, effectively prevents aerobic corrosion, protects the electrode, and prolongs the service life of the electrode. Amount of resistance reducing agent The economic dosage of the resistance reducing agent shall be determined according to different soils, and the laying thickness on the grounding body shall be between 5 and 15 CM Construction requirements for resistance reducing agent 1) Pre-construction inspection items and requirements: ① The resistance reducing agent shall be the product of the same brand and model. ② The water is clear and free of pollution, and the water is free of sediment and other sundries. ③ The size and shape of the trench and hole shall meet the design requirements, the four walls shall be relatively flat, and there shall be no sundries in the hole and trench. ④ The vertical grounding electrode shall be placed in the center of the hole, and the horizontal grounding electrode shall be placed in the middle horizontally, and the distance from the trench bottom shall not be less than 40mm and shall be uniform (if necessary, it can be fixed with a thin wire). ⑤ The grounding downlead has been painted with antirust paint according to the design requirements and has been initially set. 2) adding water into the prepared resistance reducing agent according to the weight ratio of water to the resistance reducing agent of 0.4-0.6: 1.0, and fully stirring the mixture until the mixture is in a sticky state. The amount of water used for horizontal grounding is just enough to wet all the dry powder and stir it into paste. The water addition amount of the resistance reducing agent for the vertical grounding hole can be the higher value as the case may be. Excessive water addition will prolong the construction time. 3) Pouring, coating and preliminary inspection: gently pour the prepared pasty resistance reducing agent into the grounding trench and hole (to prevent debris and sundries from mixing into the resistance reducing agent) until the grounding electrode is completely coated without omission, and preliminarily measure that the coating thickness is not less than 40mm, the four walls of the borehole are full, and supplement if insufficient. 4) confirmatory test and backfill tamping. After the initial setting of the resistance reducing agent, carefully check that the resistance reducing agent coating surface is uniform, full and free of omission and impurities. The thinnest thickness of the coating body is not less than 40 mm. If it is insufficient, it should be supplemented with resistance reducing agent. After checking, remove the fixed thin line, gently backfill the fine soil without hard objects and branches, with a thickness of more than 200mm, and then add other soil and tamp it. The surface of the compacted backfill shall be slightly above the surrounding ground level. 5. Acceptance (1) During construction, the well depth shall conform to the design standard. (Construct according to the original design. If the design requirements are not met, the design shall be changed.) (2) Deep well grouting shall be fully filled without gaps, so as to better play the role of grounding electrode in reducing resistance. (3) The welding at the lap joint shall meet the requirements to ensure full welding without insufficient welding. And that weld spots are subject to anti-corrosion treatment to ensure the service life. (Follow-up serial, please look forward to,DHD Drill bit, Jun and electronic original, reproduced please specify the source http://www.junhedianzi.cn/junduiguofang/209.html) return to Sohu, see more Responsible Editor:. wt-dthtools.com

Fecha de Publicación: 08-11-22

Nucleic Acid Extraction Grinder Easy Fine Grinding of Tissue Samples _ Samples

Descripción: Original Title: Nucleic Acid Extraction Grinder Easily Realizes Fine Grinding of Tissue Samples Nucleic acid extraction grinder is a powerful laboratory instrument and equipment, which is a common tool for laboratory sample preparation. Not only can be used for nucleic acid extraction and biological tissue cracking, but also can be used for RNA grinding extraction, protein grinding extraction, tissue grinding and the like. It is controlled by stepless speed regulation system, which can easily adjust the grinding speed suitable for grinding various parts. A super flexible, super fast and super efficient multifunctional biological sample homogenizer integrating grinding, cracking and homogenization. Crushing, mixing, homogenizing, cell breaking and the like of a sample are realized through the reciprocating vibration of the tungsten carbide small balls or the stainless steel small balls in the sample tube, cbd centrifugal extractor ,jacketed glass reactor, so that rapid crushing and homogenization treatment can be carried out on hard, soft, elastic and other samples, and the requirements of a physical and chemical analysis laboratory are met; and grinding tanks with different volumes and different materials are configured, so that dry grinding, wet grinding and freezing grinding can be carried out, Cell disruption and DNA/RNA extraction may also be performed. The highlight of the grinding instrument is that it can be operated conveniently and safely to a greater extent. Due to the integrated motor switch, the instrument can only be started when the cover is closed. Exclusive system for easy and secure fastening of grinding pots up to 100ml in volume. Grinder A step of grinding by a grinder for nucleic acid extraction 1. Tissue samples are first dispensed into suitable centrifuge tubes. 。 2. An appropriate amount of lysis medium was adde to that centrifuge tube. 3. Then tighten the cover centrifugally. ? Insert this into the freezer adapter. 4. Use a special adapter clamp ? Place the entire frozen adapter in liquid nitrogen for 3-15 minutes. 5. Reuse special adapter clamp ? Take out the freezing adapter as a whole, place it on the grinder, and tighten the fixing handle. 6. Set Grinding Speed and Time ? Start the grinder 7. Finally, after the grinder stops, ? Remove the freezer adapter and remove the centrifuge tube. Precautions before using the nucleic acid extraction grinder: 1． The matching LW kit can be used to extract DNA/RNA protein from samples quickly, efficiently, stably and in batches. Expand the full text 2． 1Hz = 30 rpm/,jacketed glass reactor, 1Hz = 100RPM 3． . Conventional adapters can be placed in the refrigerator to give the sample a cool environment while working. 。 It can be equipped with a refrigeration adapter, which can be immersed in liquid nitrogen for more than 30 minutes. 4． The noise emission value for the working environment depends on the type of sample and the setting of the grinder. The parameters in the table are in no-load state. 5． . Usually used for Small samples of DNA and RNA isolation can be prepared in disposable centrifuge tubes. Adapters available in Teflon ? Hold 5 or 10 disposable sample tubes for cell disruption. Cell tissue is rapidly and efficiently disrupted in a very short time in a multiple sample tissue mill ? No additional cryogenic cooling is required. Grinder Nucleic Acid Extraction Grinder Content Source: Guangzhou Boqi Biotechnology Co., Ltd. Return to Sohu to see more Responsible Editor:. toptiontech.com

Fecha de Publicación: 08-11-22

Common faults and maintenance methods of rotary evaporator/rotary evaporator _ vacuum

Descripción: Original Title: Common Faults and Maintenance Methods of Rotary Evaporator/Rotary Evaporator Rotary evaporator/rotary evaporator is a kind of common laboratory equipment composed of motor, distillation flask, heating pot, condenser tube and other parts, which is mainly used for continuous distillation of volatile solvents under reduced pressure, and is often used in chemistry, chemical industry,rotovap distillation, biomedicine and other fields. The instrument is mainly controlled by electronics, and it may break down in the use process, which will affect the performance of the product and the results of the experiment, so the operator needs to master the solutions to the common faults of the rotary evaporator. Rotary evaporator/rotary evaporator The following are the common faults and solutions of some rotary evaporators/rotary evaporators compiled by the editor: 1. After the instrument is connected to the power switch ? The power indicator is not on: if the power line is not connected or connected incorrectly,nutsche filter dryer, just connect the power line; if the power switch or circuit board fails, stop using it immediately and contact the manufacturer or professional maintenance personnel. 2. The motor does not rotate : If the indicator light of the electric cabinet is on, check whether the connection of the plug inside and outside the electric cabinet is loose or broken, and then re-insert the plug to connect the broken line; if the indicator light of the electric cabinet or the digital display is not on, update the fuse or confirm that the power supply is normal; if the frequency converter is interfered by high frequency and displays "O. U." ", rotary vacuum evaporator ,wiped film evaporator, remove the fault according to the frequency converter manual. 3. The bath is not heated : The green indicator light in the temperature controller is on but does not heat, and the temperature controller displays "over" or "000", which can be solved by replacing the heating ring, solid-state relay or relay board, temperature controller, detecting the probe wiring or updating the probe. 4. The vacuum can't be pumped. : It is possible that there is solvent in the container, and it is limited by the pressure of the saturated ejector, so it is necessary to empty the solvent and try again after the bottle is empty; the capacity of the vacuum oil pump is reduced, so it is necessary to change the oil (water) and clean and overhaul the vacuum oil pump; the vacuum hose joint is loose, and the vacuum meter leaks, so they need to be detected and eliminated along the vacuum pipeline section by section; if there are sundries in the discharge valve and pressure control valve, they can be cleaned; If the glass wool sandwich panel is damaged, it can be renewed or repaired. 5. Rotary evaporator /Noise or noise of the rotary evaporator: It may be caused by the wear of the seal ring, which can be replaced with a new one; or it may be caused by the wear of the internal gear, lack of oil at the driving part, or motor failure. In this case, stop using it immediately and contact the manufacturer or maintenance master. 6. Poor pressure leakage and vacuum degree : It is possible that the glass rotating shaft is worn, the seal ring is worn, the seal ring is poorly installed, the sealing gasket of the decompression nozzle is aged,thin film distillation, and the vacuum hose is aged. It is enough to update the problem parts. 7. Abnormal rise and fall : It may be the failure of the circuit board or motor, or the wear or rust of the sliding bearing. For this, the operator should stop the operation of the instrument immediately and contact the professional maintenance personnel. Return to Sohu to see more Responsible Editor:. toptiontech.com

Fecha de Publicación: 08-11-22

News | Will Oil Prices "Fall"? _ Brent Crude Oil _ Gasoline _ Price

Descripción: Original Title: Information | Will Oil Prices "Fall"? Jingtai Capital After a new round of refined oil price adjustment, domestic No.92 gasoline has entered the "9 yuan era" in an all-round way, while No.95 gasoline in some areas has officially entered the "10 yuan era", and even in a few areas, No.95 gasoline has broken through 11 yuan/liter. For example, after the price adjustment in Hainan, the highest retail price of No.92 gasoline is 10.43 yuan/liter, and that of No.95 is 11.1 yuan/liter. The next round of oil price adjustment is at 24:00 on June 28. International oil price news International oil prices fell on the 15th. By the end of the day, light crude oil futures for July delivery on the New York Mercantile Exchange fell $3.62, or 3.04%,winterization filtration, to $115.31 a barrel, while London Brent crude oil futures for August delivery fell $2.66, or 2.20%, to $118.51 a barrel. Expand the full text | The impact of oil price of 10 yuan If calculated according to the 50L family car fuel tank,decarboxylation after extraction, this price increase will cost about 12 yuan more to fill up, which seems not much, but compared with the beginning of the year, the oil price will rise by two yuan, an increase of 25%, and it will cost 100 yuan more to fill up the 50L fuel tank. Increase the travel cost of every family with a car by 25%. According to the data released by the Traffic Management Bureau of the Ministry of Public Security, China has 302 million cars (all calculated according to 50 L fuel tanks), 50l rotovap ,hemp extraction centrifuge, which will cost at least 3.6 billion yuan more to fill up. In fact, this data is larger, which is a real increase in social costs. The important thing is that most of the transport vehicles in our country are fuel vehicles at present, and the rise in gasoline prices will lead to the rise in transport prices. This part of the rising price will also appear in our daily life. Even if you don't drive, the rising price of gasoline will still affect you. In addition, crude oil not only has the function of producing gasoline, but also can produce heavy oil and aviation kerosene. Large cargo ships and aircraft are big oil consumers. With the rising price of crude oil, the use cost of these people will also rise, which will eventually be superimposed on our daily life. Moreover, crude oil is also an important chemical raw material, and the rising price of crude oil will lead to the rising price of plastics, asphalt and other products. The international oil price has dropped by 6.83%, and the next oil price adjustment is expected to fall. International oil prices have fallen by more than 5.5%. At present, Brent crude oil prices have fallen to the range of $113 per barrel, and US crude oil has also fallen to around $109 per barrel, which makes the next oil price adjustment very hopeful to usher in a decline. As of June 18, light crude oil futures for July delivery on the New York Mercantile Exchange fell $8.03, or 6.83%, to close at $109.56 a barrel, while London Brent crude oil futures for August delivery fell $6.69, or 5.58%, to close at $113.12 a barrel. Next Monday, the negative operation of domestic crude oil change rate will continue to widen. According to the national refined oil mechanism, the price adjustment amount is less than 50 yuan and will not be adjusted. It is hoped that this round of price adjustment will exceed the red line of price adjustment. It has been too long and has not been reduced once. It is not difficult to see that long-distance transport trucks are under greater pressure! This round of domestic refined oil price adjustment will start at 24:00 on June 28, 2022. END The article is the information point collated by Jingtai and does not constitute investment advice. Please read it carefully and return to Sohu to see more. Responsible Editor: (function() { function getBrandHtml() { var brands = ,wiped film distillation, html = ''; for(var i = 0; i < brands.length; i++) { var brand = brands; if(brands.length i+1) { html+= '

Fecha de Publicación: 08-11-22

Precautions for use of molecular distillation method _ sealing

Descripción: Original title: Precautions for use of molecular distillation method In Wuxi Shengze refrigeration and heating temperature control system, it is used in molecular distillation method. Then, what should we pay attention to in the use of molecular distillation method? Can users understand clearly? If the molecular distillation method cannot be vacuumized,wiped film evaporator, check whether each joint and interface are sealed, whether the sealing ring and sealing surface are effective,cbd crystallization equipment, whether the vacuum grease between the main shaft and the sealing ring is properly coated, whether there is air leakage in the vacuum pump and its hose, and whether there are cracks, molecular distillation systems ,thin film distillation, cracks and damages in the glass parts. Before installation, the ground mouth, sealing surface, sealing ring and joint of the molecular distillation method shall be coated with a layer of vacuum grease. Water must be added to the heating tank before it is powered on. Dry heating without water is not allowed. Screw it into the safety hole to prevent damage to the flask. Glass parts should be handled with care. They should be washed, dried or dried before installation. The heater of molecular distillation method must be equipped with a safety valve. The steam pressure in the heater shall not exceed 0.01 Mpa. The safety valve shall be checked frequently to see if there is any fault. Do not be careless. In any case, the steam valve shall be closed when the machine is stopped. When the molecular distillation circulating pump fails and stops running, the steam shall be shut down immediately, and the operation of the molecular distillation pump, whether the oil level is normal and the amount of cooling water shall be checked frequently. Regularly observe the motor current and motor temperature of each equipment in the molecular distillation method. It is strictly prohibited to cut off any part of the material in the molecular distillation method under any circumstances. The liquid level of the evaporator should be adjusted slowly and should not be too large or too small. When the ambient temperature of the equipment is below 0 ℃, the accumulated water in the equipment and its pipeline should be drained to avoid freezing or blocking the pipeline. If the molecular distillation method is used improperly, it may lead to certain failures of the molecular distillation method. Therefore,wiped film distillation, attention should be paid to the above operations in the operation of molecular distillation. (This article comes from the network, if there is infringement, please contact to delete.) Return to Sohu to see more Responsible Editor:. toptiontech.com

Fecha de Publicación: 08-11-22

Valoraciones (0)