Steam pump sub-steam reciprocating pump and steam jet pump. 1, steam reciprocating pump: vortex pump (also known as vortex pump) is a vane pump. Vortex pump is mainly composed of impeller, pump body and pump cover. The impeller is a disk, and the leaves on the circumference are arranged radially. An annular flow passage is formed between the pump body and the impeller, and the suction inlet and the discharge outlet are both located at the outer circumference of the impeller. There is a partition between the suction port and the discharge port, thereby isolating the suction port from the discharge port. We divide the liquid in the vortex pump into two parts: the fluid between the blades and the fluid in the fluid path. When the impeller rotates, the centrifugal force causes the circumferential velocity of the liquid in the impeller to be greater than the circumferential velocity of the liquid in the flow path, so that the "annular flow" shown in FIG. 1 is formed. Again, as the liquid from the suction inlet to the discharge outlet follows the impeller, the combined result of these two movements causes the liquid to produce the "longitudinal vortices" shown in Figure 2 (green) that are the same as the impeller steering. So get the name of the vortex pump. It should be specially pointed out that the liquid particles in the pump body circumferential velocity less than the impeller circumferential velocity. In the longitudinal vortex process, the liquid particles repeatedly enter the impeller blades (Figure 2), through the impeller blades to transfer energy to the liquid mass within the flow path. Every time the liquid particle passes the leaf, it gains energy once. This is also the case of the same impeller diameter, the vortex pump than other vane pump head high reason. Not all liquid particles pass through the impeller. As the flow rate increases, the "annular flow" weakens. When the flow is zero, the "ring flow" the strongest, the highest lift. Since the liquid in the flow channel is impinged by the liquid to transfer energy. At the same time also cause a greater impact loss, so the efficiency of the vortex pump is relatively low. 2, steam jet pump: After the steam throttling throttling mouth, the speed increases the pressure to reduce the formation of low pressure area at the nozzle, resulting in suction to drive the media flow. The principle and the general blasting equipment nozzle is the same. Steam jet pump works and structure Steam jet pump is based on high-speed steam jet from the Laval nozzle to carry gas flow, it has the following characteristics: (1) The pump has no mechanical movement and is not restricted by the conditions of friction, lubrication and vibration. Therefore, the pump can be made with high pumping capacity. Reliable work, long service life. As long as the appropriate choice of structural materials pump for the exclusion of corrosive gases, gas containing mechanical impurities and water vapor and other occasions extremely favorable. (2) Simple structure, light weight, small footprint. (3) working steam pressure of 4 ~ 9 × 105Pa, in the general metallurgical, chemical, pharmaceutical and other enterprises have such a source of water vapor. Because of the above characteristics of steam jet pump, it is widely used in metallurgical, chemical, pharmaceutical, petroleum and food industries. 2. Working principle Jet pump is composed of working nozzle and diffuser and mixing chamber. Working nozzle and diffuser these two components form a special section of gas flow pipe changes. Air flow through the nozzle can be pressure energy into kinetic energy. The pressure difference between the working vapor pressure P0 and the pump outlet pressure P4 causes the working steam to flow in the pipe. In this particular pipe, steam passes through the nozzle outlet to this area (mixing chamber) between the diffuser inlet and a negative pressure area appears due to the high velocity of the steam flow. The negative pressure here is much lower than the working vapor pressure P0 and backpressure P4. At this moment, the sucked gas is sucked into the mixing chamber, the working steam and the sucked gas are intermixed with each other for energy exchange, the working steam is transferred to the sucked gas by the kinetic energy transformed by the pressure energy, the mixed gas flow is diffused in a certain section (Figure 3, section 3), the mixed gas flow after the wave speed reduced to subsonic ω "3, the pressure of the mixed gas flow increased to P" 3 subsonic airflow in the diffuser gradually expanding section When the flow is decelerated pressurized mixture flow in the diffuser exit, the pressure increased to P4, the speed dropped to ω4, so the jet pump is also a gas compressor. 3. Multi-stage jet pump structure Figure 2 is a typical five-stage pump structure diagram. Usually single-stage ejector compression ratio does not exceed 10, the working pressure is not less than lOkPa. So when the need for lower working pressure, then by two or more ejectors and condensers in series, called multi-stage jet pump. The role of the condenser is to condense the condensable steam in the mixture partially to eliminate the load of the lower ejector. The structure of the condenser are hybrid, surface and jet three forms. Condenser according to its injection pump system in the installation location, is divided into the front condenser, the middle condenser and the rear condenser. The front condenser is installed in front of the primary ejector inlet, primarily to reduce the load on the primary pump. Only when the pumping mixture contains a large amount of condensable steam, and the steam partial pressure stronger than the cooling water temperature corresponding to the saturated vapor pressure can only be used. Intermediate condenser installed in the middle of the multi-stage pump, the specific location should be depending on the mixture into the condenser steam partial pressure and cooling water temperature, and its role is to reduce the load on the lower pump. After the rear condenser is installed in the final stage ejector, mainly to eliminate the last stage ejector exhaust, noise, and sometimes used to recover the unwanted ejector heat. 4. Simple calculation method (1) Calculation of nozzle throat diameter D0 (1) Where G0 - working steam consumption (kg / h), G0 = Gh / μ. Gh is the amount of gas being drawn (kg / h), μ is the emissivity coefficient, which can be found in Table [1]. P0 - working steam pressure (Pa) (2) Calculation of diffuser throat diameter D3 (2) Where GK - through the diffuser throat air flow (kg / h) GZ - Vapor flow through diffuser throat (kg / h) P4 - diffuser outlet pressure (Pa) (3) Calculation of condenser diameter D (3) Where GΣh - into the condenser mixture flow (kg / h) vΣh - The specific volume of the mixture entering the condenser (m3 / kg), which can be approximated by the specific volume of saturated water vapor detected by P4. More keyword search: steam pump