Flame heater is a kind of equipment that uses the heat energy generated by the combustion of flame to heat. It usually consists of a fuel supply system, an ignition system, a combustion chamber, a Heat Exchanger and an emission system. The fuel supply system usually uses liquefied gas, natural gas or diesel as the fuel, the ignition system is used to ignite the fuel, the combustion chamber is where the fuel is burned, the heat exchanger is used to transfer the heat generated by the combustion to the heated object, and the emission system is used to discharge the exhaust gas produced by the combustion. Flame heater is widely used in industrial production, construction sites, wild camping and other occasions, has the advantages of fast heating, high efficiency, easy operation and so on.
The main business scope is various heaters, waste heat boilers, pressure vessels, supportingair preheaters, air coolers, furnace accessories and accessories, and provide equipment installation, with EPC ability of projects. At present, our customers have covered all large and medium-sized petrochemical enterprises in China and established long-term strategic cooperative partnership with them. Products are exported to Southeast Asia, Middle East, and other regions.
Fired Heater,Hydrogenation Project,Hydrogen Production Eguipment,Heating Furnace Equipment Jiangsu Gelan Environmental Technology Co., LTD , https://www.glkj2010.com
Application of Multipurpose Pump Control Valve in Safe Water Supply
[Preface] In the feed pump station, in order to make the centrifugal pump start lightly, it is usually required to close the outlet valve of the pump first and then start the pump unit. When the speed reaches the rated speed, the outlet valve will be opened gradually. In order to prevent the system medium Backflow, but also must be installed in the pump outlet check valve; due to the general swing check valve instantaneous closure often endanger the water pump system water hammer accident, so it is necessary to set effective water hammer elimination device. Currently used more electric butterfly (gate) valve supporting micro-resistance slow closing check valve to achieve the above purpose, but in the field of use electric butterfly (gate) valve often appears to be closed, motor burnout and gear reduction gear Damage and other failures: The slow-closing micro-resistance check valve to adapt to a narrow range, can not adapt to large changes in flow, pressure, and its regulation needle easy to block, leading to the damper can not move and other failures affect the normal safe water supply. First, the multi-function pump control valve Introduction Multi-function pump control valve is a new type of hydraulic control valve, a valve alternative electric butterfly (gate) valve, check valve and water hammer eliminator three devices. It can automatically open the pump when the slow opening, closing the pump when the closure and slow closure, without any electrical control and other power and manpower, but also without the hydraulic device. The main advantages of the multi-function pump control valve are: (1) no operational control required. When using the pump start and stop the valve before and after the water pressure difference as a control power, with the opening and closing of the pump automatically opens and closes the function. (2) Valve opening and closing movements can effectively prevent accidents caused by water hammer pressure wave. According to field use survey and measured, stop the pump water hammer pressure peak at 1.3 times the working pressure. (3) Without on-site commissioning, a wide range of applicable conditions. (4) basically no maintenance. As a valve to replace the three valves, maintenance and repair workload greatly reduced. (5) resistance loss is small. The use of streamlined, wide body design, resistance loss than the same kind of products abroad to reduce more than 50%, such as DN200 products in the v = 2m / s economic flow conditions, multi-functional pump control valve loss of 0.7m, while foreign similar products Is 1.5m. Second, multi-function pump control valve structure and working principle 2.1 Structure Multi-function pump control valve structure shown in Figure 1, by the main valve and external components. The main valve includes the valve body, the main valve plate, slow closing valve plate, valve stem, seat and diaphragm controller (including valve cover, diaphragm seat, diaphragm, diaphragm pressure plate): external accessories control valve, filter , Emptying valve, micro check valve. One micro-check valve is a special accessories, in the direction of its check-stop with a current limit. See Figure 2 for installation. 2.2 The working principle Before the pump starts, the valve outlet pressure on the role of the main valve plate, the valve is closed, while the diaphragm controller connected to the pressure on the water chamber, the lower chamber and the valve inlet is connected to the low pressure. Pump starts, the valve inlet pressure gradually increased, while pressure water through the valve inlet side of the connecting tube slowly into the diaphragm controller cavity, the main valve plate to achieve a slow opening, the opening speed can be adjusted by the control valve. When the pump stops and the pressure of the valve is reduced, when close to zero flow, the main valve plate closes rapidly under its own gravity. As the pressure at the inlet of the valve is reduced, the pressure water at the outlet of the valve enters the upper chamber of the diaphragm controller through the connecting pipe, the lower chamber water is pressed back to the inlet of the valve through the connecting pipe at the inlet of the valve, the slowly closing valve plate is slowly closed, Adjust by control valve. The closure of the main valve plate and the slow closure of the slow closing plate complies with the two-phase closing rule, which can effectively eliminate the water hammer. Third, a few technical issues 3.1 The design of the connection pipe micro-check valve role is to ensure that the valve opening time is greater than the motor start-up time, so that light motor start; the same time to avoid opening the valve caused by excessive pressure to open the water hammer. Valve opening time by the control valve according to field conditions pressure settings. The control valve can adjust the water flow speed of the upper and lower chambers of the diaphragm controller so as to adjust the slow closing time; the diaphragm controller can be repaired when the valve is closed; and the valve can be manually operated when the pump is in normal operation. The filter is to ensure the cleanliness of the water in the upper and lower chambers of the diaphragm controller. As the valve in a process of opening and closing the water is reciprocating access, itself has the role of backwash, it can also be used for poor medium conditions. 3.2 The elimination of water hammer valve characteristics From the principle of destructive water hammer we can see that there are two main factors to reduce the water hammer boost: (1) just before the water flow velocity v is as small as possible (close to zero ) Close the main valve plate; (2) make the valve closing time t is water Hammer phase u = 2L / α (α - pressure wave transmission speed, m / s; L - pipe length, m) 5-10 times , It is possible to limit the actual water hammer pressure h within a safe range so as to eliminate damaging water hammer hazards. The opening degree of the main valve plate of the multi-purpose pump control valve is determined by the impact force of the water flow in the pipeline. The main valve plate opening degree is high when the flow rate is high: the valve plate opening degree is small when the flow rate is reduced: when the flow rate approaches zero, Board closed. The whole process is consistent with the elimination of the principle of water hammer close fast, so the elimination of water hammer works well. Multifunctional pump control valve slow closing valve plate closed, the diaphragm must be formed on the lower chamber pressure difference before it can be achieved, that is, the main valve plate is closed, the slow closing valve plate can only be closed, it is impossible to produce slow closure and Speed ​​closed synchronization phenomenon. 3.3 The valve resistance characteristics In order to reduce the water flow resistance, the design reduces the weight of the main valve plate, using a streamlined spacious body design. The Hunan Hydraulic Machinery Quality Supervision authorized station test, DN200 multi-function pump control valve resistance coefficient of about 3.8, while the same specifications of the pipe swing check valve resistance coefficient of 5.5. 3.4 Diaphragm Design Diaphragm quality is a direct impact on valve performance and service life of the key components, after a variety of screening, the selection of neoprene as raw material, the middle of the nylon fiber network to strengthen; by the Hunan rubber Monitoring authorized station testing, 650,000 fatigue fatigue without rupture, can be used for more than 10 years. 3.5 Maintenance No other external hydraulic or electric components, the basic without maintenance, and the use of a wide bonnet, valve parts can be removed completely, easy maintenance. Fourth, an example Ankang Railway Water Works conditions: head 80m; elevation 68.4m; flow 850 / h; outlet diameter DN400; pipe length of 6km. Use JD745X - 10 DN400 multifunctional pump control valve. According to the field test, the slow closing time is 30s and the stopping pump pressure peak value is 0.95MPa (the original configuration is electric butterfly valve and micro blocking retarder butterfly valve; the peak value of stopping pump pressure is 1. 2 ~ 1.4MPa). After stopping the pump the maximum reversal speed of the pump 600r / min, the same as the original configuration. The theory of calculation, multi-function pump control valve stop pump peak pressure of 0.98MPa, check valve stop pump peak pressure of 1.88MPa. The multi-function pump control valve, micro-slow retreat butterfly valve and the normal check valve three settings are caused by the pump stop water hammer results list is as follows: Water hammer boundary conditions Multifunctional pump control valve Electric butterfly valve + ordinary check valve Electric Butterfly valve + micro-slow sluice butterfly valve Hmax / Ho 1.225 1.5 2.4 βmax / βo 0.4 0.4 Table 1 Comparison of three kinds of valve water hammer boundary conditions Hmanx-stop pump pressure peak Ho-normal working pressure βmax-stop pump unit maximum reverse speed βo- Rated speed (1450r / min) As can be seen from the above table, multi-function pump control valve for the elimination of stop water hammer has a significant effect, in full compliance with "Pumping Station Design Code" and "pump operating procedures"; multi-function pump control valve also Pump can start to open slowly, to eliminate open pump water hammer. IV Conclusion After field use proved that multi-function pump control valve can effectively eliminate destructive water hammer, water supply system to improve the safety and reliability of significant features, and easy to debug and installation, ease of operation and management, less maintenance, in line with the " 2000 City Water Supply Technology Development Plan "in the water supply equipment automation, mechanization and modernization requirements, is the replacement of pump station new valve products.