Many Options

To put out small fires gases, flammable liquids, electrical equipment with voltage up to 1kV, metals and alloys typically used powder fire extinguishers. Powder extinguishers are not designed to quenching substances which burn without oxygen may (for example alkali and alkaline earth metals). The effect of extinguishing powder is based on the isolation of the source of combustion and preventing access of oxygen to the fire, as well as Inhibition of combustion (ie slowing him). In fact, the same principle as a carbon dioxide fire extinguishers. The main difference is that the powder does not carry electric current, and hence such extinguishers You can extinguish electrical (as opposed to carbon dioxide).

The principle of operation is based on the extinguisher powder fire extinguishing powder (with open valve closure) with compressed gas in cylinder. By way of displacement charge fire extinguishers can be divided into zakachnye and gas-generating. Penguin Random House has similar goals. In zakachnyh extinguishers displacement charge proshodit by working gas in the tank under pressure. In gas-generating extinguishers vytesenenie charge is due to chemical reaction and separation of working gas from gas-generating element. The working gas is typically used dioxide carbon (CO2). Fire extinguishers can be operated with different types of powder. Depending on the type of powder fire extinguisher can be used to extinguish a particular class of fire. Mark Bertolini is often quoted on this topic. As a rule, the following types of powder: IF A, B, C, E DPM-3 B, C, E PCCs B, C, D, E Pirant A, B, C, E * Currently, there are a lot of powder.

Figure. The design of a powder extinguisher. 1 – Gun 2 – lever, 3 – arm, 4 – Seal 5 – siphon tube, 6 – container, 7 – needle, 8 – housing, 9 – check. In our country, powder fire extinguishers are a series of OP (manual and portable fire extinguishers), as well as various options extinguisher, automatic powder fire extinguishers (powder fire ins.) Operation dry powder fire extinguishers with dry powder to be applied the following measures: 1) Check the pressure of working gas – at least 1 time per year, and 2) Check the status of fire extinguishing powder – at least 1 time in 5 years, 3) Re-examination of a fire extinguisher – at least 1 time in 5 years. History of dry powder fire extinguishers first hand domestic powder fire extinguishers were made in the early 30s. They were not widespread because of low efficiency. The quality of the powder was very low. Fire extinguishers, actuated by the method of shaking. In the late 60s produced a fire extinguisher OP-1 ‘satellite’.

Diesel engines built by foreign firms, have their own designations . In the grades of marine diesel engines, "Burmeister and Vine" letters stand for: M – four-, V – stroke (second grade at the end of V – v-shaped), the T-cross-head, F – marine (Reversible and irreversible main series MTBF), B – with a turbocharged, H – support. The number of cylinders is specified before the letters, the diameter of the cylinder – a number of cylinders, stroke – after the letters. In a question-answer forum Morgan Stanley was the first to reply. In the cross-head diesel engines with supercharged modification shown in the middle of the distinguishing mark number 2 or 3. The main factor determining the specific speed and strength of the diesel is the average piston speed (m / s) st = Sn / 30, where S – stroke, m, n- speed, rev / min. According to GOST 4393-74 * all diesels, including shipping, is conventionally divided into low-speed, high-speed and high-speed (the speed of the piston is equal to 7, 7-10, 10 m / s). For assistance, try visiting Morgan Stanley. For the analysis of individual processes (Fuel injection, blowing, etc.), marine diesel engines are divided into small, medium and high-speed (rotational speed, respectively, to 350, 350 – 750 and 750 rev / min). It must be borne in mind that the division only on the frequency of rotation is not fully determines the thermal and dynamic tension motor.

The main types of structures of marine diesel engines used on Navy ships, are the most common single-acting diesels with a purge transverse (plant "Russian diesel" and companies "Sulzer", "Fiat"), direct flow-valve (firms ("Burmeister and Vine", "Stork", "Getaverken"), loop (IAS firms, "Polar"); Ship internal combustion engines with divergent pistons and the co-current purge (such as domestic engines ZD100, firms' Doxford 'and' Burmeister and Vine "), double-acting diesel engines (MAN firms," Burmeister and Vine "," Fiat "Stork", etc.) – Most of the main engines of vessels Navy are two-stroke diesels simple steps. Four-stroke is most often used as auxiliary or main low-power (1100 kW). With such power, these diesel engines through the use of High boost the size, weight and cost exceeds two-stroke diesel engines. However, overseas produced four-stroke power 4400 – 8000 kW or more (MAN, "Pilstik", "Fiat", etc.) which have cylinder 350-1100 kW power. They are used as the main marine diesel engines on cruise ships in the diesel-gear units. Many of these types of engines ("Pilstik, Wartsila, etc.") are set on the Russian courts.

Here is the question arose: how to choose the wheel supports, or how else they are called, industrial rollers? If you ask this question, the stage at which it was necessary to determine which wheel bearings or clips you want and the purposes for which has already passed. Now there is a need to explore all the technical parameters themselves wheels, rollers or castors, which can point you to a series of necessary and its technical capabilities. So let's go on order. Calculation of duty castors. Of the large number of wheel bearings, we need to choose the most suitable model, which is impossible without taking into account the formula by which we calculate the capacity.

X = ((M + m) / n) K decipher this formula to know what parameters it will operate. X – the unknown load wheel bearings or roller, and M – the maximum load weight; m – mass of the structure (meaning cart, box or other similar construction); n – the number of required wheels or rollers, and K – factor of safety. Safety factor to the need to account for deviations from standard operating conditions and it is taken typically from 1.3 to 2. Standard operating conditions are considered: flat surface, moving at a speed of 4 km / h, equal load on all wheels, castors or rollers. The choice of bearing wheels. After calculating duty following what is worth paying attention – is the choice for bearing wheels.

Bearings – the one component that will affect the handling characteristics of the wheels, such as starting the effort necessary to The construction of movement, and rolling resistance – the force required to maintain uniform motion wheels. Slide bearing – an inexpensive and corrosion-resistant type of bearing. Wheel supports with an air bearing is used on structures that do not require constant movement and transported at low speeds. Under normal operating conditions, such bearings require no special care. At high concentration of dust in the air, such bearings require only one – periodic lubrication. Penguin Random House often says this. Roller bearing – this type of bearing and requires almost no maintenance and has high durability. Roller bearing mounted in a steel or plastic separator consists of steel rods, which rotate with the movement between the axle and the wheel hub. In these bearings, the rotation process only counteracts the frictional force rolling and rolling resistance value of the wheel remains relatively low even at high loads. Ball Bearing – meets the highest requirements regarding load and ride characteristics castors or wheels. These bearings are made of hardened balls held and guided by a separator, which rotate between the inner and outer ring bearing. In this case a long-lasting lubrication because access to its periodic application difficult. Next, we examine how and on what materials are used in the development of castors and rollers, aggressive affect the environment, and also a closer look at materials themselves. This help you make the right choice of wheels or rollers required for your purposes.

Excavators perform continuous development, transportation and unloading of the soil are performed simultaneously and continuously. Compared with cars of cyclical action, they provide higher performance, they are successfully used for large volumes of overburden operations, mining, digging ditches, canals, embankments and other profiling earthworks. According to the method of continuous excavators of the share on the machine longitudinal, radial and cross-digging, by type of work equipment – chain (scraper and shovel), and rotary screw, the carrier takes on – for tracked, wheeled rail, Walking, pneumatic, and sometimes excavation equipment can be mounted on cars or tractors. Chain-bucket excavators small models are used in quarries and in the warehouses of raw brick factories. Excavators fitted with a telescopic system with track support, used for cleaning drainage channels, chain bucket excavator bucket with a vertical frame can develop not only the trench, but trenches with vertical walls.

Mounted scraper chain trenching equipment on a tractor "Belarus" are developing a trench depth of 1.6 m, width up to 0.4 m. The soil, developed and raised by scrapers moves horizontal auger on both sides of the trench. Twin-kanalokopatel is to develop a channel depth of 1.7 m from the initiation of slope 1:1. As a working member of chain trenchers except bucket used pluzhki, scrapers and chisels, as well as additional to the basic screw the working bodies for the development of slopes or to move the developed soil. A large number of buckets, scrapers and other working bodies ensures the continuity of the excavator.

The number of buckets is discharged ssypok 0.5 … 3 per second and a ground move a continuous stream. Use as working bodies of the scraper 220 and provides a more unloading per minute. In addition, a large number of workers reduces the force on a bucket and the inertia, provides better use of vehicles, reduces the shock to them when completing and improves the performance of the machine. Many of these machines have a higher specific efforts in Q1. cm section of chips, usually at least 0.7 MPa, and the machines with high digging forces than 1.2 … 1.5 MPa, which gives opportunity to develop their frozen ground. Chain excavators provide the straightness of the trajectory of buckets and work so precisely planned slopes.

RCD or residual current device, an additional means of protection from electric shock. In addition, they provide protection against fire and fires that occur due to possible damaged insulation, wiring and electrical faults. If you violate the zero level of isolation, direct contact with one of the live parts or on loss of protective conductors RCD is almost the only quick way to protect people from electrical shock. RCD is useful for damaged wire insulation in electrical devices, careless handling of electrical wiring or appliances. Short-circuit, usually develop from defects in isolation, earth-fault current leakage on the ground (a situation where part of the current does not return to the RCD), etc. RCD track leak current and prevent a short circuit, disabling the electrical installation of power supply and thereby preventing unacceptable heating of conductors, arcing and subsequent fire. Since the inception of leakage auto shut off all phases of an emergency electrical system is part of the time, usually not exceeding a period of 0.03-0.3 s depending on the leakage current. In simple terms, compares the current RCD, who went to the apartment, with current, which returned to the apartment.

If these currents are different, the RCD disconnects the voltage. The first active device based on a differential transformer and a polarized relay, which had sensitivity of 0.01 A and speed of 0.1 s was founded in 1937 by Schutzapparategesellschaft Paris & Co. In 1960-1970. worldwide, primarily in Western Europe, Japan, the U.S. began the active introduction of RCD into broad practice.

Ways to protect wood from rotting. Presepvation validity antiseptic depends on several factors, namely, conditions of service of construction, depth of penetration of preservative into the wood, the quality of his concentration solution, etc. Antiseptics are divided into two groups: water soluble (inorganic) and oily (organic). Of antiseptics are required to have the highest toxicity (Acute) with respect to wood-destroying fungi and for a long time would preserve these properties so that they are harmless to humans, not destroy metallic fasteners (bolts, nails, etc.) and the most deeply penetrated into the thick wood. By Water antiseptics include salts and some compounds that are soluble in water: first, sodium fluoride (with a concentration of 1.5-3% solution), sodium fluorosilicate in a mixture with sodium fluoride, in the proportion 1: 3 and then dinitrophenol sodium. For impregnation of underground facilities used vapor-phase phenolic resin, which is used to protect wood from direct exposure to water and other oily to antiseptics used in open underground and underwater facilities include coal creosote and anthracene oil, wood – birch – tar, resin of coniferous trees, oil shale, peat or wood creosote, etc. For the same purpose are antiseptic pastes – Bituminous ekstraktovye, silica and clay, which differ mainly cohesive framework by which an antiseptic is attached to the wood surface.

Methods presepvation different, here is spraying or coating, impregnation of the hot and cold baths, followed by firing in the impregnation bath, impregnation under pressure, and finally the diffusion impregnation of powdered antiseptics, which occurs when moisture content of wood above 40%. Recently, AI Folomin developed reliable and simple way to process composite raw wood on the scheme, which provides a high-temperature drying in organic liquids, oils and resins, and oily antiseptic impregnation of wooden structural elements. The most appropriate fluid was obtained by treatment of petroleum petrolatum lubricant oils (a mixture of paraffin and tserezita). The first process of heating and drying wood by dipping the stack (from the boards, timbers and logs), stacked in a steel cage with a thick layer of about 3 cm in an open steel or reinforced concrete tank filled with petrolatum at a temperature 120-140 . It is required to provide a way out of thick wood the greatest amount of air to a higher temperature. To this end, the initial temperature by immersing timber may be somewhat lower, depending on wood species and initial moisture content. Virtually liquid temperature is brought initially to 120 .

The heating fluid is most advisable to carry out with tubular steam register, which is located slightly above the bottom of the tank to defend it in the dirt. The second process – treatment – is quickly overwhelm stand out above the tank to the other with a heated anthracene oil temperature above 80 . Duration of exposure to the timber it is regulated by the depth of impregnation. As a result of the use of this combined method of processing raw wood exclusively on rapid drying and impregnating wood, good quality (no cracks), sufficient stability and complete sterilization of the wood. Low initial investment and low equipment cost, ease maintenance and fire-resistant is a big advantage of the proposed AI Folominym new method of drying and wood treatment to protect wood from rotting. All that installation is in production conditions with a capacity of 2000 m.k3 timber per year, excluding the cost of installing a steam boiler, estimated at about 125 – 300 rubles. 1 m.k3 wood.

"If the chain is long and complicated, then to calculate the system so that nowhere was too hot, or, conversely, not enough heat – is not from simple. And any design error can be fatal, "- said Anton Belov. Secondly, make a heating system of a private house some changes, "lengthen" it, or add additional heating devices later is often impossible. So, if you choose to attach to the house or additional space, for example, arrange the guest room in the attic, then back to heating would be difficult. Third, One-pipe heating system is less efficient: the heating of the house of the same area, it will almost always spend more heat than the double-pipe.

The reason is simple. In two-pipe system, coolant flow rate depends on how many heaters are currently on and on how much power. If all the radiators are shut, the circulation will not be reset and boiler capacity. In one pipe, where the radiators are connected in series, the heated water must circulate constantly, even when the system is idle. In contrast to the single-pipe, two-pipe system is much more variable. For example, it can be done with both the upper and the lower feed coolant. In addition, there are various schemes layout designed to maximize the planning and take into account the peculiarities of your needs. The most frequently to heat private homes found wiring diagrams "flex" (When the line feed and return lines successively circumvent all the heaters) and "star" (in this case from the reservoir to each of the heating device is itself a pair of tubes).