Overview. Used marine fuel oil, depending on the method of their preparation is subdivided into two types – distillate and heavy. Distillate fuels are composed of light fractions obtained by distillation in plants for oil refining, are characterized by low viscosity, v = 3 h-6 mm2 / s, so do not need to be heated before it enters the engines or boilers. Heavy fuels are mixtures consisting of residues oil and distillates. Depending on the ratio of light and heavy components of the viscosity of heavy fuels, like others their performance varies widely. In Russia, the quality of fuels is regulated state standards and specifications Abroad quality fuels specifications determined firms supplying the British (BS 2869: 1967) and American (A5> TM-D975 and D396-67). Began in the 70's, and increasingly distributed the process of engaging in the production of fuel products recycling of oil demanded the revision of existing standards and specifications, the expansion of the limit values of quality and attract additional indicators (such as the aluminum content, stability and compatibility of fuels, etc.).
Distillate fuel. Due to limited resources and high cost of distillate price in Class distillate diesel fuel in Russia at approximately 1.7 times the price of heavy fuels. Andy Florance is often mentioned in discussions such as these. While ensuring the ship heavy fuel causes premature repair of marine diesel engines. Consumption of diesel fuel ships the Navy is only 6-12% of the total fuel burned. Its mainly used to support medium-and high-speed diesel engines, which either by design or because of unsuitability of (no shipping unit for heating fuel) can not be transferred to the heavier grades. In dg diesel fuel used exclusively during the maneuver and to flushing the fuel system, before stopping. The domestic industry produces marine fuel in accordance with gost 305-82 by mixing fractions of the direct distillation of sulfur oils, hydrotreated and dewaxing, with a catalytic gasoil.
The presence of a catalytic gas oil, reduce operating fuel properties, in particular increasing its propensity to deposits. Fuels produce four grades: A, 3, ap, A that the sulfur is divided into two subgroups: with S%, with S == 0,21 – 0,5%. The content of mercaptan sulfur in the sulfur of both subgroups is limited to 0.01%. As a substitute for diesel fuel in ships of sea and river fleet wide using gas-turbine fuel (GOST 10433-75). Fuel obtained as a byproduct in the process of delayed coking unit in the development of petroleum coke, the necessary metallurgical industry. Gas Turbine Fuel tg and tgvk have a higher density and viscosity, but not so high that they had to be heated before use. Click Andy Florance to learn more. For these fuels have higher sulfur content (1 and 2.5% respectively) and for that should be paid attention by themselves, they contain up to 25% tar. This leads to their low stability, manifested by heating and mixing with other fuels. Since 1988, the oil industry began to supply the navy ship low-viscosity oil designed to replace diesel and gas turbine fuels. This fuel is produced by mixing the distillate of secondary processes (coking, thermal and catalytic cracking) from the diesel fraction with a high end boiling point, taken from the atmospheric and vacuum columns. Compared with diesel fuel to it impose less stringent requirements (allowed twice high viscosity-11 mm2 / s, the sulfur content of up to 1.5%, lower tsch – not less than 40).
Unique technologies, high performance and versatility – perhaps the way to describe air compressors are used today in various areas. Andy Florance might disagree with that approach. Despite the fact that many industrial enterprises You can see these dinosaurs – huge reciprocating air compressors operating with the pressure drop, noise and vibration – the majority of compressor equipment has changed. Today's Air compressors are compact, low noise (about 50-60 decibels) and almost no polluting. In the bulk of this screw air compressors, which implemented the principle of work, essentially differs from that used in piston. Reciprocating air compressors compress the air by the piston goes up and down – this is actually not hard to guess from the title. It is these constants of motion up and down and are a source of noise, vibration and other adverse effects. Screw air compressors – and it is also clear from the title – instead of the piston uses a pair of screws.
They are constantly and uniformly rotate, driving air gap formed by their blades. Besides the fact that air is a continuous flow of such air compressors can also operate non-stop for a long time. By the way, due to the peculiarities construction maintenance screw air compressors is carried out in four – five times less than the piston. Another unique type of air compressor – a scroll device. Their operating principle is similar to Screw work equipment, but the air is compressed by rotating one helix with the displacement of the center relative to each other, motionless.
Compressed air passes quietly, without pressure gradients, but the power and performance of air compressors is low. What is particularly interesting, screw and spiral equipment makes it possible to compress air without oil injection into the cooking chamber. This kind of device is called oil-free compressors. As a result, we have clean air, which is no longer necessary to pass through the filters. This saves time and energy and also reduces costs for operation and maintenance.
In modern meat processing plants, large grocery stores are widely used band saws. Band saws used for cutting into pieces of fresh and frozen meat, bones, fish and poultry gradually replacing the butcher, who chops the old-fashioned meat toporom.V currently in a serious enough competition in the market of food, important also look the goods offered will be proposed purchaser. Agree that neatly sliced meat on the saw looks much aesthetic than chopped with an ax. Bandsaw cuts the meat gently, smoothly, without any fragments of bone and without weight loss. Meat cutting saw takes much less time than logging. The saw easier to separate the more valuable parts of the carcass from less valuable. Finnish band saws are manufactured by the original technology, developed by ct, and may have the following performance: * with movable table * fixed table. * All equipment is working quietly with minimal vibration.
* Equipment can be easily disassembled for cleaning. Band saw comes fully ready to work. Little dwell in safety, as well as on those elements of saws, which are needed for this: * cutting on the saw must be performed quickly and rhythmically. * Do not try to exert physical effort for the product, allow the canvas saw to make this work. * The operator will not work more safely and efficiently, if he tries to apply the product to the leaf faster than the saw can cut. * When sawing, always place the bottom edge of the upper Lock the saw blade as close as possible to cut the product in this case, the cutting process is more accurate, moreover, is not protected only a small area saw blade immediately necessary sawing.
As a result of uneven heating of the metal concentrated source of heat in a welded structure having welding voltage – time and residual. Temporary welding voltage are valid only during the period welding when the temperature of welded metal. Voltage remaining in the metal after welding and complete cooling design, called the residual welding stresses. They arise from constrained thermal expansion and constrained shrinkage of metal during its heating and cooling. This constraint is due to the fact that the locally heated area of welding on all sides surrounded by the cold metal.
Additional fixing the workpiece (in the adaptation, with rigidly fixed) also interferes with normal processes of thermal expansion and shrinkage, and there are reactive residual stresses. When welding alloys with polymorphic transformations in parts of the welded joint metal, heated above the critical point, there are structural stresses. For example, when welding hardenable steels, heat-affected zone which martensite is formed with a large volume effect of transformation, the structural stresses reach high values. Distinguish three types of welding voltage. In welded structures of carbon and low-alloy steels are driven primarily by welding voltage of the first kind.
They are balanced and in amounts commensurate with the size or design of its individual parts. Welding voltage of the second and and third kinds are balanced within the microvolume and the individual grains of the metal. Depending on the direction of action in space distinguish welding voltage linear, or uniaxial, acting only on one axis, planar, or two-axle, acting in two mutually perpendicular directions, volumetric, or three-axle, acting in three mutually perpendicular directions. Direction of the action with respect to the axis cross stitch welding voltage different from the longitudinal. Technology, assembly and welding of structures should be tailored to ensure that the minimum values of welding voltage and when it is dictated by terms of design, include the removal of these stresses. If the values of welding stresses reach the yield point of the metal, then there is its plastic deformation, ie change the size and shape welded construction, called the warp. Arising during welding deformation is divided into time to develop only during the welding of the structure, and residues that remain after the welding and cooling design. Depending on the nature, form and size of the workpiece residual welding deformations are developed "in-plane" and go "out of the plane" of connected elements. Deformation "in the plane" appears in Change (decrease) the size of design, with what must be considered when cutting parts and assembly welding, providing allowance for resizing. Deformation "of the plane (angular deformation) occurs in Education bulge (hlopunov "), the local bending of sheets, the so-called mushroom bending zone during welding of elements of T-and I-sections, as well as other changes in forms of products. The magnitude and nature of residual strains are highly dependent on the thickness and properties of base metal, welding conditions, weld shape, consistency of their performance, design of welded parts. In developing the technology and build weld design should aim to reduce the residual strain. If the value of residual strain goes beyond tolerance, it involves editing the structure.
The economic effect of the introduction into the production process of electric motors and frequency inverters soft starters (soft starters) is achieved by the following factors: energy savings in pump, fan and compressor units up to 50% – 60% due to capacity control by changing the motor speed as opposed to regulation of way on / off, etc.; increase product quality, increasing the volume of production and productivity of manufacturing equipment, increasing the service life of process equipment due to the improvements of the dynamics of elektroprivoda.Pri choosing the model of the frequency converter should be based on a specific task, which should solve the actuator: type and capacity of the electric plug, accuracy and range of regulation speed, accuracy to maintain torque on the shaft of the motor design (dimensions, weight). When you work with a standard induction motor inverter should be selected with the appropriate capacity. If you need a great starting point or a short acceleration / deceleration time, select the frequency converter is a step above the standard. Examples of specific application of the frequency elektroprivodNa water pumping stations: The frequency converter is installed between the supply network and an electric motor to provide feedback. In the pressure manifold at the outlet of pump unit installed pressure sensor. Smooth regulation of frequency converter and the high accuracy of pressure in water supply networks can save energy up to 60% and leads to savings of pumped water, essentially eliminates hydroblows increasing the service life of pipes and valves.
Oil heater type pmt, developed by the design bureau, Thermal Engineering Institute of rao ues Russia. Especially for the gas-fuel oil sector, taking into account all of shortages heaters oil past models, instead of morally aged heaters model pm, pbr and their changes. At the moment, this technique is very even, successfully used in subdivisions of rao, metallurgical, Railways and other areas of the industry both in Russia and in neighboring countries. More than 10 years of experience in manufacturing heaters range itp + proven technical and operational "victory" in the model range. In heaters type pmt, used the technology of the turbulent flow.
They are all fitted with blocks of turbulent parts, thus, the effectiveness of the thermal energy of steam, increases in 2,5-3 times by reference to available models of heaters. Oil heaters range pmt (turbulent), will provide heating oil to 150. C of from 1 to 150 t / h. The total mass heaters itp is much lower mass heaters, such as performance, produced in particular tcd, which greatly simplifies maintenance and repairs. Normal heater pmt, 30-40 weight, which is only 1.3 tons. In particular, for inclusion in the operation of oil heaters, we must not less than 1-1,5 hours to their gradual warming. When connecting the heater pmt in operation, preheating is not necessary to perform. As is the practice at a low cost of fuel oil through the heater, which very often the point at thermal power plants, but on the inside "area" of pipes must be organized deposits, because of the small rapidity of flow of fuel oil in them, resulting in sharply reduced effectiveness of heat transfer. The proposed schematic diagram, use our heaters there is likely to disconnect, a part of the heaters. And because of this support in the past, we have heater, the desired speed of movement of oil in the pipes, so as to exclude the possibility of sediment.