Low Pressure Coal Fired Steam Boiler In Textile
First Affiliated Hospital of Bengbu Medical College, responsible for staff to feedback to our company, this boiler to use less smoke production, in line with the special requirements of the hospital surroundings and national requirements for flue gas emissions. During the boiler installation and operation, square quick technical staff also always concerned about the dynamic boiler, parties can feel really real fast customer service, using fast boiler is assured. --customer feedback
The heat loss of exhaust smoke is the largest of all kinds of heat loss in boiler. Generally, the heat loss of exhaust smoke is 6% of the heat fed into the furnace, and the heat loss of exhaust gas increases 0.5% when the temperature of exhaust gas increases by 12 ℃ and 15 ℃. So the exhaust temperature is one of the most important indicators of boiler operation. The following are several possible causes of increased flue gas temperature in the furnace: (1) slagging and ash accumulation on the heated surface. No matter it is the slag accumulation in the water-cooled wall of the furnace, or the ash deposition in the superheater, convection tube bundle, economizer and preheater, the thermal resistance of the flue gas measurement will increase, the cooling effect of the flue gas will become worse due to the deterioration of the heat transfer, and the exhaust temperature will rise. (2) excess air coefficient Big. Under normal conditions, the exhaust temperature increases with the increase of excess air coefficient at furnace outlet. After the increase of excess air coefficient, although the amount of smoke increased, the rate of smoke increased, and the convection heat increased, the increase of heat transfer was not as much as that of the increase of flue gas. It can be understood that after the increase of smoke speed, the flue gas leaves the heating surface without time to transfer heat to the working fluid. (3) the air leakage coefficient is too large. The flue gas leakage in the furnace and rear shaft of a negative pressure boiler is inevitable and the leakage coefficient allowed by a certain heating surface is specified. When the air leakage coefficient increases, the effect on the exhaust temperature is similar to that of the superheated air coefficient. And the air leaks away. The closer the furnace is, the greater the influence on the rise in exhaust temperature. (4) Water supply temperature. When the steam turbine load is too low or the high pressure heater is out of line, the feed water temperature of the boiler will be lowered. Generally speaking, if the fuel quantity is kept constant, the heat transfer temperature difference of the economizer decreases and the heat absorption of the economizer decreases when the feed water temperature is increased, which makes the exhaust temperature increase. (5) moisture in the fuel. The increase of moisture in the fuel increases the amount of smoke, thus increasing the exhaust temperature. (6) Boiler load. Although the boiler load increases proportionally, the amount of smoke, the amount of steam, the amount of water supplied, and the volume of air increase proportionally, however, the flue gas temperature at the furnace outlet increases proportionally. Increase, so that the exhaust temperature increased. After increasing the load, the outlet temperature of the furnace increases, the heat transfer temperature difference of the convection heating surface increases and the heat absorption increases. Therefore, the more the convection heating surface is, the less the influence of the boiler load on the exhaust gas temperature is. (7) fuel varieties. When the low calorific value gas is fired, the radiative heat transfer in the furnace decreases due to the decrease of furnace temperature, and the non-combustible components in low calorific value gas, mainly N _ 2, CO _ 2 and H _ 2O, increase the amount of flue gas, so the exhaust temperature increases. Although the excess air coefficient of furnace outlet is lower than that of coal burning, the ash content in the fuel oil is very low after the pulverized coal furnace is changed to burn oil, although the excess air coefficient at the furnace outlet is lower when burning oil. There is no larger ash particle in flue gas, and there is no cleaning effect of larger ash particle on the heating surface, and the convection heating surface is polluted more seriously. Therefore, combustion is not good, often smoke-emitting boiler smoke temperature rise. When there is a steel ball dust removal device at the tail, the exhaust temperature is slightly lower than that of burning coal because the tail is cleaner. (8) the operation mode of pulverizing system. For a closed pulverizing system with a silo, when the pulverizing system is in operation, as a part of the water in the fuel enters the furnace, the furnace temperature decreases and the flue gas increases, and the cold air leaking into the pulverizing system enters the furnace as a primary air during the operation of the pulverizing system. Reduction of air flow through air preheater To raise the exhaust temperature. On the contrary, when the pulverizing system is shut down, the exhaust temperature decreases.
Introduce some common sense about the boiler 1, the critical speed of the circulating fluid bed boiler. Gas flow rate corresponding to the minimum fluidization velocity or become known as the critical fluidization velocity. 2, the flow characteristics of circulating bed boiler? A high combustion efficiency of the fuel adaptability 2 3 4 desulfurization efficiency is low nitrogen oxide emissions high combustion intensity 5, 6 simply small cross-sectional area of the furnace fuel and coal pretreatment system 7, a large load adjustment range, adjustment is easy to implement fast ash 8 utilization. 3, the partition circulating fluid bed boiler furnace and the corresponding characteristics into dense and dilute phases, a lower dense phase zone of the furnace, filled with hot materials, is a stable source of hot, heat storage is a thermal store , flow therethrough in an upper dilute phase zone of the furnace, the fuel air are required. 4, the positive balance calculation boiler efficiency, combustion of coal, boiler heat losses What? Coal particles is heated and dried: volatile combustion and precipitation: coal particles swell and rupture: re-cracking and coke burning carbon particles and wear. Heat loss 1 2 3 Chemical incomplete combustion loss of physical mechanical incomplete combustion heat of the loss heat loss 4 5 ash. 5, the charging cycle 4 Effect Effect Effect amount of the main factors affecting combustion in the boiler of a coal particle size distribution and particle 2 was 3 Effect fluidization velocity excess air factor 5 bed temperature Dense Phase 6 . 6, the basic form of the heat transfer in? In the heat transfer process, there are three basic ways of heat transfer: thermal and heat transfer, convective heat and radiant heat transfer. 7, their role in recycling and recycling processes? By the economizer feed water into the steam drum, a descending pipe into the water wall, by absorbing the heat released by the combustion of the fuel heating the water in the saturated steam passes through the heat absorbing further heat saturated steam into dry steam heating. 8, sewage, drainage pipe What? Sewer: blowdown drum door (left and right) turn on the water accident door, front door header sewage, sewage tank after the door, left the door header sewage and right door header sewage, sewage water jacket door (about) Dipleg sewage door. Drainage pipe: the low temperature superheater inlet header hydrophobic doors, front / rear desuperheater hydrophobic door header, the high-temperature superheater inlet / outlet header, the header hydrophobic dispensing door. 9, then what are pipe drum? Meter and accessories? Superheater, economizer recirculation duct, platoon expansion tube, a condenser tube, soot blower tube, economizer inlet pipe, the discharge pipe accident, centralized downcomer platoon expansion, a water level gauge, a thermometer, security door, pressure gauge, gas-water separator, header. 10, the cyclone structure and working principle? Cylindrical body, the central cylinder, a cone, a loop seal, the material returning leg, from the high temperature flue gas out of the furnace, two left and right into the two cyclones, increase after turning flue flue gas velocity in the cylinder the center of rotation of the form cylinder back down into the cone upwardly from the central cylinder wall Shuaixiang excluded smoke particles under high effort when the cone reaches the end coupled with its heavy fall below the loop seal. 11, Refeeder role? The ash from the circulation loop seal into the furnace combustion chamber 12, acting characteristics superheater? The use of flue gas heated to a certain pressure saturated steam superheated steam. 13, bag filter works and composition? Principle: inlet flue gas-containing flue dust particles into the lower caul plate over the flue dust reduction chamber, and then through the outlet to reduce the wind speed of the flue draft fan withdrawn via the discharge plenum chamber clean flue upper portion of the bag filter the atmospheric composition: inlet flue, the caul plate, the reduction of flue gas chamber, bag, net flue gas plenum chamber exit gas, ash silo, rotating ash blowing device, the air reservoir. 14, to the mounting position of the coal feeder, the number, composition mounted on the front wall of the furnace, the number of stage three consists of: a motor, a belt coal feeder, reducer, the motor slide. 15, the process of slag from the furnace down the three tap outlet derived by the discharge of slag, after water cooling to cool to a certain temperature onto the cooling belt-type transfusion Pa, and then transported by the inclined transport slag to the slag bin .
what is chain grate boiler
Grate firing has been the most commonly used firing method for combusting solid fuels in small and medium-sized furnaces since the beginning of the industrialization. Coal, waste and biomass fuels are usually burned in grate boiler. In the chain boiler, the coal is moved backward from the front of the grate, and the air from the bottom up to the furnace, and as the furnace is constantly moving backwards, the fire, combustion, burning and other stages occur in sequence. Traveling or chain grate stokers feed coal out onto a rotating metal belt that supports the fire. Solid fuel is fed from a hopper. Grate speed is automatically controlled to maintain desired steam pressure. Burning progresses as the belt moves from front to back of furnace. Combustion is essentially complete at the back end of belt, and ash is dumped off into an ash pit there.