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"Small submersible sewage pump selection and installation" content introduction
Abstract: This paper introduces the main principles and contents of compiling National Standard Atlas for Selection and Installation of Small Submersible Sewage Pumps, and explains the related problems. According to "2000 National Building Standard Design Compilation Work Plan" issued by the Ministry of Construction, China National Machinery Design Institute No.1 and Jiangsu Institute of Fluid Mechanics Institute jointly assume the national standard of "Small Submersible Sewage Pump Selection and Installation" (01S305) The preparation of the task. The Atlas has been published by China Institute of Building Standards Design Institute since July 28, 2001 in all parts of the country. Compared with the traditional horizontal sewage pump (PW type), submersible sewage pump has the following salient features: (1) The use of new sealing materials and sealing process, the pump body can work long hours into the water. (2) Adopting a large passage, an impeller with anti-winding anti-clogging function greatly expands its application range. (3) The use of advanced electronic control technology, so that the pump overload, lack of phase, leakage, water level alarm and other automatic protection and automatic level control. (4) The use of mobile installation and automatic coupling device with a fixed installation, to meet the engineering construction of a variety of sewage, wastewater lifting sites, and for the pump maintenance, maintenance, overhaul great convenience. It is precisely because of the above several characteristics, so that the pump in the 20th century, 90's has been rapid development and extensive application. With the widespread application of submersible sewage pumps in construction projects, engineering designers all over the country have reflected in recent years, hoping to have a book to solve the large-scale selection of submersible sewage pumps used in construction design And install the standard atlas to regulate the selection and installation methods to reduce duplication of efforts in the design process. It is for this reason that the Ministry of Construction formally approved the establishment of the national standard atlas for selection and installation of small submersible sewage pumps in 2000. 1 The Atlas of the scope of this Atlas (1) The Atlas for the basement and outdoor sewage pools, sump sewage, waste water pumping emissions. (2) is drained, wastewater temperature does not exceed 40 ℃, pH is 5 ~ 9 (QX series is 6.5 ~ 8). (3) When used for pumping up and discharging industrial wastewater, the quality of waste water should not cause corrosion to submersible sewage pumps and pipes. (4) QDX, QX series small submersible pump is only applicable to pumping pumping of cleaner wastewater in the basement pump room, bicycle garage and other places. 2 Submersible Sewage Pumps Included in This Attempt Group (1) Small submersible pump [QX (WQK), QDX (WQKD) series] should be used for cleaner wastewater pumping. (2) ordinary submersible sewage pump (AS, AV, QW, WQ series) should be used for shorter residence time of sewage, wastewater pumping. (3) Automatically submersible submersible sewage pump (JYWQ series), should be used for more sediment, longer residence time, the density of 1 ~ 1.3 t / m3 of sewage, wastewater pumping. 3 Atlas Submersible Sewage Pump Installation Indoor sewage pool (sump) with mobile installation (hose) (single pump), fixed installation (pipe) (single pump, double pump) and with automatic coupling device Installation (single pump, double pump) 3 kinds of forms. Hose connection is only limited to the mobile installation of motor power? N?? 7.5 kW submersible sewage pump and exhaust pipe? DN? ≤ 100 mm occasions. Outdoor sewage tank only with automatic coupling device with a fixed installation (double pump) a form. For the installation of submersible sewage pumps for fire elevator drainage pits, two rigid pipe connections or two fixed auto-couplings shall be adopted, and the effective volume of the water collection wells is not less than 2.0 m3 and the rated flow of the submersible sewage pump is not less than 36 m3 / h 4 into the Atlas of submersible sewage pump flow, head and motor power range as the starting point for the compilation of Atlas of this album is to solve the basement and outdoor sewage pools, sump pollution, waste water pumping emissions, does not involve Municipal engineering independent rain, sewage pumping station and the need for submersible sewage pump project, so included in the Atlas of submersible sewage pump (including small submersible pump) specifications are: discharge diameter? DN? 20 ~ 150, flow rate of 1.5 ~ 200 m3 / h (of which the discharge diameter of small submersible pumps is ~ DN 20 ~ 50 and flow rate 1.5 ~ 15 m3 / h; 200 m3 / h). Head 6 ~ 32 m, motor power 0.18 ~ 22 kW (including small submersible pump 0.18 ~ 1.5 kW, submersible sewage pump 0.75 ~ 22 kW). In order to facilitate the flexible selection of designers based on the quality of the sewage to be lifted, we believe that the submersible sewage pumps of different discharge diameters should overlap in a certain range. This set of Atlas into the various types of discharge diameter submersible sewage pump flow range is determined as follows: DN 20 ~ 45, flow 1.5 ~ 15 m3 / h; DN 50, flow 10 ~ 25 m3 / h; , Flow 20 ~ 40 m3 / h; DN 80, flow 25 ~ 60 m3 / h; DN 100, flow 45 ~ 100 m3 / h; DN 150, flow 100 ~ 200 m3 / h. According to the design of the project completed by our hospital and brotherhood over the years, the scope of the above specifications can meet the needs of the vast majority of architectural engineering design in all walks of life. 5 On the automatic uniform submersible sewage pump JYWQ series of automatic uniform submersible sewage pump is based on the common submersible sewage pump design a special diversion device, the use of pressure in the pump cavity flow, with the motor speed of rotation to 10 ~ Rinse the bottom of the sump (sump) at a swirling velocity of 20 m / s, mix the sediment and stir it, and then drain it with water to prevent accumulation of sediment in the sump (sump). The pump is suitable for the kitchen restaurant oil separation waste water and domestic sewage containing manure, with more mud sediment underground garage waste water and other sediments, longer residence time of sewage, waste water discharge. Compared with the conventional design of a submersible sewage pump discharge pipe connected to a DN25 short-cut valve and rubber hose used to wash the sewage pool compared to the practice of submersible sewage pump with automatic mixing, often Rinse, without special operations, to ensure that the bottom of the accumulation of sediment accumulation and many other advantages. 6 on the submersible sewage pump pipe diameter calculation principle According to the relevant provisions of the rules, the Atlas of this sub-set of submersible sewage pipe diameter calculation principle is: Submersible sewage pump flow by the nameplate flow (high efficiency point flow) calculation, a single pump The discharge pipe flow rate is controlled at 1.2 ~ 1.8 m / s; in the case of double pump installation, it is basically considered as 1: 1, but also under special circumstances (such as fire protection and short-term displacement greater than the design second flow rate) Bench pump may work at the same time. At this time, the common discharge pipe is superimposed on the nameplate flow, irrespective of the work point offset. Therefore, the dual pump common discharge pipe when the single-pump working speed control in the 0.75 ~ 1.2 m / s, dual-pump working speed control in 1.5 ~ 2.4 m / s. 7 on the submersible sewage pump pipe material According to the relevant provisions of the regulations, in addition to the mobile installation of hose connection parts using fabric reinforced rubber hose, the discharge pipe can be hard plastic water supply pipe, centrifugal casting ductile iron drainage pipe, steel pipe , Steel-plastic composite pipe. The pressure capacity of pipes and fittings shall not be less than 0.6 MPa. What kind of pipe, selected by a single project design staff. 8 On the set of submersible sewage pump pipe fittings set diagram set in the submersible sewage pump discharge pipe are provided with control valves, check valves, flexible rubber pipe joints and pressure gauges. The control valve recommended gate valve, but also can be used according to need butterfly valve; check valve recommended spherical sewage check valve; pipeline attachment pressure levels are considered 1.0 MPa. In the process of drawing atlas, many experts and manufacturers suggest that the best not to gate valve, check valve and other piping accessories arranged in the sewage pool, in order to facilitate maintenance and management. Therefore, in the album, the indoor sewage tank will be the valve and other accessories arranged in the pool outside the pipeline; outdoor sewage pond is another set up a valve well for user maintenance and management to create favorable conditions. 9 Determination of the effective volume of the sump (sump) The effective volume of the sump (sump) when the pump is automatically switched (excluding the part below the stoppump water level) is not less than the discharge capacity of the maximum one pump for 5 min and Pumps shall not be activated more than 6 times per hour; the effective volume of water collecting pits can be calculated as average hourly flow of not more than 6 hours when the pump is under manual control. Based on the above requirements, considering the vastly different projects, we only set out the geometric size range or the minimum geometric size of the sump (sump) applicable to this type of submersible sewage pump in the Atlas. For example, a small submersible pump can be used in a total of 7 kinds of collecting pits of 500 mm × 500 mm × 50 0 mm-1 200 mm × 1 200 mm × 1 000 mm; the depth of the hose-connected mobile installation tank should be less than 2.5 m; The fixed pipe installation should be less than 3.0 m deep, the fixed self-installing tank should be 1.5-3.5 m deep, and the depth of outdoor sewage pool should be ≤6.0 m. What needs to be emphasized in particular is how to minimize the footprint of sump (catchment pit) and maximize the effective water depth of the sump (catchment pit), which we consider more in the process of compilation aspect. Because of the generally tight area in the basement of a building and the relatively small area available for the disposal of sumps (sumps), it is also not possible to reduce the size of the sump (sump) due to factors such as construction, maintenance, management, safety and cost. Puddle) designed too deep. Therefore, it is very necessary to reduce the depth of the pump water as much as possible. According to the structural features of the submersible sewage pump, we set the stop water level to be slightly higher than the center of the pump impeller by 20 to 50 mm. In the general description, we emphasize that this water level is considered in accordance with the intermittent operation of the submersible sewage pump. Dirty sewage pump for continuous operation, you should ensure that the motor was submerged 1/2 height. 10 In the past engineering design projects, we generally only consider the ventilation and ventilation of the basement sewage pump room, while ignoring the ventilation of the well room of the pump house kitchen and toilet sewage pool, resulting in well room Harmless gases can not be ruled out in time, endangering the health of equipment maintenance personnel. Atlas of this Atlas requires that the basement sump of the building (sump), especially the grease trap of the kitchen and the domestic sewage pool with feces, should be set up to the atmosphere or near to the ventilation system for indoor drainage system atmosphere. In addition, in order to keep the air in the basement and sewage pumping station clean and prevent the contamination of gas in the well room, we installed a closed manhole cover at the installation and maintenance openings of the sump (sump) cover. Cover material is cast aluminum, gray cast iron and ductile iron 3 kinds. The size of the closed manhole wellhead shall be determined according to the dimensions of the submersible sewage pump plus the appropriate allowance for each type of model submarine sewage pump, in which the allowance in the lengthwise direction (A) is not less than 100 mm and the margin in the widthwise direction (B) is not less than 150 mm; The average net size of the sewage wells in the closed sewage tank with the sewage drained up is 600 mm × 600 mm. The minimum net size of the closed well head of the sewage tank for pumping sewage in the kitchen and toilet is 700 mm × 700 mm. 11 On the submersible sewage pump electrical control In addition to small submersible pump installed in the place of duty on and off by the manual control, sub-sewage pump atlas of this album are automatically controlled by the level of automatic control device. The high water level (h1) Kai pump, low water level (h0) to stop the pump, the alarm water level automatic alarm at the same time standby pump automatically put into operation (Atlas alarm level above the pump water level 100 mm); 2 pump rotation work, spare Pump automatically switches. The electronic control system matched with each production plant has the automatic protection function to the pump and the motor such as overload, phase loss, undervoltage, short circuit, leakage, overtemperature, over humidity and water immersion. In addition to the type of liquid level automatic control device float level switch, such as sewage does not contain or contains only a small amount of suspended impurities, designers can also use the input pressure sensor and supporting secondary instrument. Atlas of this book in the compilation process, many brothers and sisters brothers and participating manufacturers of production support and support. We think that the contents of the Atlas have the full range of options for selecting submersible sewage pumps, diverse installation methods, detailed installation dimensions, compact installation drawings, and the use of a sump aeration system and airtight covers. After the publication of the Atlas, will be the project design and user units, installation of enterprises attention and welcome. Due to the limited capacity of team members, omissions and fallacies are inevitable in the Atlas, and experts and colleagues are urged to come forward with valuable suggestions. Author Correspondence: 233017 Bengbu City, Anhui Province Machinery Industry First Design and Research Institute Tel: (0552)