(1) Equipment selection and calculation
A Centrifugal slurry pump a Pump type and selection principle The centrifugal slurry pump commonly used for slurry pressure transmission has the following types:
PNJ type PSJ type rubber-lined pump—The surface of the two pump impellers and the inner wall of the pump casing are lined with rubber. It is suitable for slurry transportation with fine particles and low hardness. Its service life is several times the general metal sand pump. It is the most widely used pump type in China's mineral processing technology. In particular, the PSJ pump has a simple structure and is easy to maintain. Many factories and mines can be self-made. At the same time, these pumps can be fed into the slurry on both sides, so it is easy to arrange.
PN type slurry pump --- is a horizontal single-stage single-suction cantilever pump. Bearing wear member which are wear-resistant cast iron or alloy steel for wear for the conveyor belt with sharp, hard, coarse particles of the slurry. However, due to the direct contact of the solid particles in the slurry with the pump body and the impeller, the pump casing and the impeller are often seriously worn, and the service life of the pump is reduced. Since the successful development of the 250PN pump, the working life of the pump has been extended by more than 2000 hours, which has solved a major problem for mine production in China. The maximum weight concentration of the delivery is 50-60%.
PH type ash pump - its performance is similar to PN type pump.
PS type sand pump————The sand pump for horizontal side water inlet is simple in structure, and the water inlet on both sides is convenient for layout and maintenance. Generally, water is not required to be sealed, only a small amount of cooling water is needed, and the pump parts can be made by ordinary factories and mines. The maximum weight concentration delivered is around 50%.
PNL vertical slurry pump --- only 2PNL, 3PNL two models, suitable for a small amount of ash wastewater in the low base of the detachment basement.
Pinggui sand pump --- a pump type made by Guangxi Pinggui Mining Bureau. Suitable for conveying pulp containing coarse-grained materials.
WARMAN slurry pump--This pump is a pump type imported from Australia by Shijiazhuang Pump Factory in 1980. It has wide adaptability, high degree of generalization, convenient assembly and disassembly, long working life, etc. Features are internationally recognized products with advanced technology. Compared with the domestic performance of the pump, the working efficiency is 7.4% higher. For example, the 4/3CAH type Walman pump is 28% more efficient than the 3PN type slurry pump. For example, the Guangxi Dachang Mining Bureau Chehe Selection Plant 8/ The 6E-AH Valman pump replaces the original 6PNJ type pump, saving 179,280 kWh per unit per year. The working life of the pump can be extended by 10 to 12 times.
The introduction of Walman's manufacturing technology consists of six series, 78 varieties, with a flow rate of 3 to 15,000 meters per hour and a head of 8 to 95 meters. The pump parts are highly versatile, different types of parts can be used interchangeably, metal lining and rubber lining can be interchanged, metal impeller and rubber sheath can be combined in various combinations, the entire Walman product series is only used Nine bearing assemblies and 12 brackets are available to meet a variety of matching needs.
Walman pumps can be divided into the following types:
Heavy-duty slurry pumps such as AH, M, HH, H—all of which are multi-stage series horizontal pumps with metal lining or rubber lining (both interchangeable). Suitable for strong abrasive transport, High concentration or low concentration, high lift slurry. The flow rate is 10 to 5400 m3 / h, and the lift can reach 6 to 95 m.
L-type light slurry pump - This pump is a cantilever horizontal centrifugal pump, suitable for conveying slurry with a concentration of not more than 30%. Compared with the AH type, the L type has the characteristics of low speed, small size and low price.
SP, SPR type submerged slurry pump --- This type of pump is a vertical centrifugal slurry pump. It can be immersed in liquid and is suitable for conveying corrosive liquids and pulp.
D-type dredger pump, G-type gravel pump—These two pumps are vertical single-pump shell structures for conveying coarse-grained mud, gravel, and slurry materials that cannot be transported by the AH-type pump.
The principles of Walman pump selection are as follows:
For the delivery of low concentration, low abrasive slurry, a light pump, ie L type, should be used;
Heavy-duty pumps, ie AH type and M type, should be used for conveying strong abrasive and high-concentration slurry;
For conveying low abrasion and high lift slurry, HH type or M type can be used;
For the slurry containing large particles, the D or G type should be used.
For the choice of speed, the impeller line speed of the metal pump should not be more than 30 m / s; the impeller line speed of the rubber pump should not exceed 25 m / s. [next]
b Performance of Centrifugal Slurry Pumps For detailed information on the clean water performance and installation dimensions of centrifugal slurry pumps ( mud pumps , sand pumps, slurry pumps, impurity pumps), please see the product samples from each manufacturer. At present, China's production of slurry pumps manufacturers throughout the country, mainly Shijiazhuang, Zigong, Benxi, Shanghai, Foshan, Changzhou and other water pump plants, of which Shijiazhuang pump plant is the largest, the product line is relatively complete.
10/8ST - AH (or M, HH);
10——The diameter of the pump suction port (mm) is removed by 25 to the integer value;
8 - the pump outlet diameter (mm) is removed by 25 to an integer value;
ST——Drive type;
HH——high lift slurry pump;
M——Medium lift slurry pump;
AH - slurry pump;
100D——L;
100——the diameter of the pump outlet, mm;
D—— bracket type;
L——low abrasive slurry pump.
40PV - SP (SPR):
40——the diameter of the pump outlet, mm;
PV - vertical bracket;
SP - submerged slurry pump;
SPR - the slurry pump under the glue. [next]
c Selection method of centrifugal slurry pump When using slurry pump to send low concentration slurry, the general calculation steps are as follows, but when pumping high concentration slurry or reducing the number of impeller rotation, the pump displacement, head and efficiency should be determined through experiments. .
(1) The amount of pulp delivered:
Q b =K×Q K +Σq s (1)
Where Q K ———the amount of pulp, m 3 /h;
K———the coefficient of process fluctuation, or take 1.1;
Σq s ——— The total water consumption of the slurry pump water seal of the previous sand pumping station of this station and this station, m 3 /h.
(2) Calculate the effective head (crude) required for the conveyor system:
H x =H j ×δ K +L×i k +h j (2)
Where H x ———effective head (excluding head loss and remaining head in the pump station), m;
δ K ——— pulp density, t/m 3 ;
H j ———the geometric height difference of the slurry delivery, m;
L———the total length of the conveying pipe, m;
i K ———head loss in the pipe, mm;
h j ———The local head loss of the pipeline is generally 5-10% of L×i K.
(3) Select the pump model to be used from the sample.
(4) Convert the clean water head to be pumped to the slurry head:
H b =H s ×δ K ×K H ×h m (3)
Where H b ———the effective head of the pump when conveying the slurry, m;
H s ——— the clear water head of the pump on the sample, m;
K H ———Head reduction rate when conveying slurry:
δ K , δ s , δ g ——— respectively the density of pulp, water, solids, t/m 3 ;
h m ———The pump performance reduction factor caused by wear, generally lining rubber with a diameter of more than 200mm; the impeller is 0.95, and the other impeller is 0.8~0.95.
(5) Estimation of the number of pumps required:
1) When connecting in series:
Where X———the loss of the head in the pumping station to be borne by each pump, the remaining head and the loss of the head due to the presence of the slurry tank;
q b ———The flow rate of each workload, m 3 /h;
n g ———Number of pumps required, Taiwan.
Other symbols are the same as before. [next]
(6) The total effective head required for the entire conveyor system is:
H t =H x +n g X (8)
The actual lift required for each pump is:
If ngH B ≥ H t means that the pump selected is suitable, otherwise, other pump types should be selected.
(7) Motor power calculation:
The motor used in the slurry pump generally uses an asynchronous motor. When the power is large, in order to improve the power factor, a synchronous motor can also be used, and the power can be calculated as follows:
Where N———motor power, KW;
Q———The slurry delivery volume of each pump, L/s;
H k ———the head of the conveying slurry, m;
H K =H s ×δ K (11)
K———the reserve factor of the motor, generally a small value of 1.1 to 1.25 large motors, and a large value for small motors;
η b ———efficiency when pumping clean water;
η j ———Unit transmission efficiency; coupling direct drive takes 1.0; V-belt drive takes 0.95～0.96; gear transmission takes 0.97～0.98;
K H ——— See formula (3)
Other symbols are the same as before.
(8) Spare pump for slurry pump:
In order to ensure the safe production of the pumping station, a certain number of spare pumps need to be installed.
(9) Performance adjustment of slurry pump:
The pump performance specified on the sample can be adjusted appropriately within the allowable range. The adjustment method is as follows:
1) Adjust the speed of the pump:
Where Q 2 , H 2 , N 2 ——— the flow rate, head and shaft power after the pump adjusts the speed;
Q 1 , H 1 , N 1 ——— rated pump flow, head and shaft power found by product sample;
n 1 , n 2 ———The rated speed of the pump and the adjusted speed.
