In view of the pump product seal leakage and reciprocating diaphragm pump structure is complex, bulky, difficult to debug and other issues, we developed a successful Q = 2m3 / h, 25m3 / h; P ≤ 0.4MPa ring diaphragm pump two products, and in 1994 yuan Month passed the ministerial identification, and access to national patents, patent number.1. According to a certain alcohol plant and fructose plant pump situation survey, the two units use nearly 360 pumps to transport oil, water, alcohol, liquor, syrup, additives and other media, the pressure difference is P = 0.2 ~ 0.5MPa, flow Q = 15 ~ 40m3 / h; choose oil pump, stainless steel pump, single screw pump, shielded pump, water pump more than 10 varieties, 50 specifications of the product, operation and maintenance of replacement parts is not convenient. Use ring diaphragm pump products, you only need to be satisfied with the two base, the installation size, the same pump, diaphragm and other parts of the same medium can replace the flow of parts of different media, maintenance and management easier. More Search Keywords: Pumps Shenzhen Xianglong Paper Product &Packaging Co.,Ltd , https://www.xlpaperbox.com
1, the structural characteristics of the annular diaphragm pump first planar peristaltic rigid ring and the annular diaphragm is different from the general rotor pump and reciprocating diaphragm pump. In addition, the existing diaphragm pumps use a sheet-type diaphragm to separate the conveying medium and the working medium, and uses a reciprocating crank-and-rod mechanism, a three-valve mechanism, and an inlet and outlet valve groups; the annular diaphragm pump absorbs the hose pump and the flexible bushing Pump and other rotor pump characteristics, the rotary drive mechanism and annular diaphragm organic combination of novel structure, with a ring diaphragm to separate the transmission medium and the drive element, the transmission medium can not be leaked to the outside. The annular diaphragm pump is mainly composed of a pump body 1, an isolation mechanism 2, a rigid support ring 3, an annular diaphragm 4, a bearing sleeve 5, a bearing 6, a transmission shaft 7, a floating pressure ring and a pump cover; the end of the annular diaphragm is supported by a bearing The cover is pressed and fixed along the axial direction, and forms a closed volume with the pump cover, the rigid support ring and the pump body. When the transmission shaft rotates, the pump body forms a liquid suction and drainage chamber by means of the inlet and outlet isolation mechanism and the rigid support ring , To achieve the purpose of non-leakage of transport medium.
The main structural features of the annular diaphragm pump are:
(1) a flat peristaltic rigid support ring is provided between the diaphragm and the pump body;
(2) annular diaphragm built-in floating pressure ring;
(3) The annular diaphragm separates the conveying medium from the lubricating medium;
(4) ring diaphragm pump unique combination of import and export isolation mechanism;
(5) without the end of the valve and import and export valve group;
(6) unique axial seal structure;
(7) There is a bearing between the rigid support ring and the transmission shaft.
2, the design points 2 .1, flow ring diaphragm pump rigid support ring and isolation components, the pump body will be separated into suction and discharge liquid chamber, with the suction and discharge liquid chamber volume changes, the media along the import to export continuous flow. As shown in Figure 2 Suction port A and discharge port B were suction, drainage chamber radial seal dead center, we can see the theoretical discharge per revolution should be:
Q;, t = 10 - "" n (RZ-r2) BK [L]
Where B - rigid support ring width, cm
R - pump body cavity radius, cm
r - rigid support ring radius, cm
K - the theoretical volume factor, the main consideration of the invalid seal angle α and structure size R, r and so on the theoretical flow rate; usually invalid seal angle α were controlled at 20. Within, K value can be accurately obtained, generally take 0.90-0.95
R = r + e design, where e is the eccentric value, cm. The theoretical flow rate of the pump is: Taking into account the pressure drop of the pump, the viscosity of the medium, the size of the gap and the influence of the pump speed on the flow rate, the rated flow rate of the pump is: Qr = KvQth Where Kp-- volumetric coefficient 2.2, Radial and axial clearance determination 2.2.1 Pump speed The relative sliding speed between the pump body, the pump cover and the rigid support ring is related to the pump speed due to the use of a flat peristaltic rigid support ring whose value can be estimated as : V = πne / 30 Shows reasonable control and reduce pump speed, you can reduce the friction and power loss, extend pump life, improve pump efficiency. As a rule of thumb, the pump speed is usually controlled in the n <300 min-1 range.
2.2.2, shaft, radial clearance inhalation and discharge chamber radial seal for the wedge-shaped gap, the axial gap for the parallel gap. Pump performance and radial, axial clearance and related structural parameters and media properties are closely related, of which the radial gap mainly based on differential pressure △ P; viscosity of the transmission medium γ; radius of rigid support ring r; eccentricity e and other factors to determine.
That is, the gap T = f (ν, r) / f (ΔP, e). Obviously, when ΔP and e increase, the gap T should be small; when ν and r increase, the gap T can take a large value.
The combination of the gap seal and the elastomeric seal in the axial seal works well, and the amount of leakage in the parallel gap can be estimated as: q = 10-5 x T3b ΔP / 1.2γL [mL / s]
Where b- gap width, cm
L-gap length, cm
â–³ P-pressure difference, MPa
ν-medium dynamic viscosity, Pa · s
T-gap value, cm
In general, a reasonable control of diameter, axial clearance can improve self-suction performance and discharge pressure, reduce pump leakage, maintain a high volumetric coefficient. Practice has proved that the rigid support ring and the pump body, drive shaft and bearing sleeve and bearing and bearing cap tolerances, radial axis dimension chain calculation is crucial. Through the design analysis and test verification, radial, axial clearance should be controlled in the range of 0.03 ~ 0.20.
2.3, the design of the annular diaphragm ring diaphragm is a circular diaphragm pump away from the transport medium and lubricating medium, the key elements of the transmission medium to achieve non-leakage, its design is different from the sheet-shaped diaphragm, we guarantee from the structure to withstand low-pressure state, through the scheduled Elongation to work under additional deformation minimal, the design to follow the following principles:
(1) There is no relative sliding friction between the inner and outer surfaces of the annular diaphragm;
(2) control the pressure difference between the inner and outer surfaces of the diaphragm within 0.1MPa;
(3) the use of floating pressure ring to form a floating support;
(4) improve diaphragm tensile and fatigue resistance;
(5) a reasonable choice of diaphragm hardness;
(6) to ensure that the membrane assembly and disassembly convenient;
(7) given diaphragm pre-elongation â–³ L.
If the size of the annular diaphragm deformation section L, while the installation size L "", then the annular diaphragm design length value is:
L = ΔL + L ""
Where ΔL = e / sin (arctge / L) -L
Usually â–³ L = 0.5-2.Omm, consider the ring diaphragm pressure lower, but contact with corrosive media and the work of the cycle of flexible with the structural size of the demanding, we and the manufacturers and research institutes developed Ding La Rubber, polyurethane rubber and natural rubber, and other septum, the comparison test, urethane diaphragm material properties and fatigue performance is better.
2.4, rigid support ring design Ring diaphragm pump rigid support ring is different from the ordinary rotor pump and reciprocating diaphragm pump. Its settings not only make axial and radial seal easy to form, but also to protect the diaphragm, to ensure that the pump has high discharge pressure and good self-priming performance.
The motion of any mass point on the rigid support ring is the reciprocal motion of the vertical axis cross section and the plane motion of the synthetic motion of the slewing motion. The design of rigid support rings should consider the use of lightweight materials or hollow structures to reduce weight and reduce inertial forces.
Under its working condition, the outer surface is subjected to the unbalanced hydraulic pressure, so that the radial force F can be absorbed by the transmission shaft. When the radial sealing point is far away from the lowest point of the combination isolation mechanism, the following formula is satisfied: Fmax = 20 · ΔP · B · r
â–³ P-pressure difference, MPa
B-rigid support ring width, cm
r-radius of rigid support ring, cm
It can be seen from the above formula, the rigid support ring to bear a greater radial force, so in the design should not only ensure its sufficient rigidity and strength, but also should consider the transmission shaft may have deflection, through the structural design to ensure that the pump radial clearance in the design Range.
3, the performance characteristics of 3.1, the performance characteristics of the ring diaphragm pump with unique structure, optimized design, reasonable parameters and high quality diaphragm and have excellent performance, mainly in the following:
(1) No leakage. As the pump diaphragm in the transmission medium and lubricating medium separated, the transmission medium can not be leaked.
(2) self-priming performance. Because of the rotary displacement pump, it has good self-absorption capacity, oil, gas and water can be mixed delivery, the pump without irrigation, direct start.
(3) adapt to a wide range. Can transport general liquid can also convey viscous medium, the application of a large range of parameters.
(4) high efficiency. Transmission structure is compact and simple, and compared with the parameter vane pump, high efficiency of 5% or more, and a wide area of ​​high efficiency.
The product is easy to serialization, universal; same seat products can be replaced flow components, adjust the pump speed and clearance to adapt to different conditions and media. At present, the annular diaphragm pump has been formed Q = 1 ~ 50m3 / h, P ≤ 1.OMPa series of products can be widely used in conveying corrosive, explosive explosive, highly toxic and radioactive and high purity or high viscosity media . In addition, according to different user requirements can be used speed control drive, but also with diaphragm alarm automatic actuator.
3.2, the product is rigid performance According to the "military ship ring diaphragm pump research" subject identification requirements, two products after 500 h type test, after testing its performance in Table 1.
Thus it can be seen that the measured performance of the product meets the key research targets of the Ministry of Machinery and has the characteristics of good self-priming performance, gas-liquid mixing and transportation and high efficiency.
In addition, we use the HM-2.0 / 0.4 type ring diaphragm pump comparative test, the delivery of different media and different pressure drop performance in Table 2. Obviously, different viscosity and pressure, the same seal gap, resulting in different internal leakage, making the volume factor is different.
4, conclusion and application Annular diaphragm pump as a new type of volume rotor leak-free pump, using a rotary drive mechanism, reducing the sliding friction lubrication points, simplifying the structure. The use of a circular diaphragm separated from the lubricating medium and transport medium, unique and novel. In addition, because of its different nature with the reciprocating diaphragm pump, rotor pump, magnetic pump, hose pump and other structures, its research and development and market potential.
The annual output of non-leaking pumps in industrialized countries accounts for 15% -20% of annual production of pumps; while the annual output of non-leaking pumps in China accounts for about 3% of total output, which is an urgent development product. The unique performance, good versatility and interchangeability of the annular diaphragm pump make it especially suitable for the pumps in the chemical industry, light industry and food industry, which can reduce the operation cost, maintain and operate conveniently and increase the economic benefits.
The pump can not only meet the military ships used to replace the sea water, sewage vertical reciprocating electric pumps and marine oil-water separator plunger pump, also has the ability to mix gas and liquid, especially for oil, gas, water Mixed transport; wharf bilge, residual oil and the remaining liquid tanker suction.