Type Selection Of Feed Slurry Pump For Filter Press
Filter press feeding pumps are widely used to feed filter presses in petroleum, chemical, starch pharmaceutical, pesticide, dye, paint, leather, paper, food and other industries. It plays a very important role in improving the efficiency of related industries. There are certain disadvantages to the use of the existing filter press feeding pump:
(1) It cannot adapt well to uneven ground.
(2) The traditional heat dissipation mechanism is easy to cause external dust to enter.
(3) The connection part is easy to cause the raw materials to drop to the ground during adjustment, which causes waste and damages the cleanliness of the site environment, and brings certain adverse effects to people’s use process.
To better meet the working characteristics of the filter press, it is best to use special equipment, the filter press feed pump. Among them, choosing a suitable pump is very important, which is very helpful in improving production efficiency, reducing the product failure rate and cost.
1. Determine the right pump
There are many types of slurry pumps with different performance curves. The performance design of Walker slurry pumps is the most advanced.
Its special hydraulic performance coincides with the gradual process of the filter press from the cavity to filling and drying. There is no valve control at the initial feeding stage, and the motor overload is caused by excessive flow rate. At the same time, the low pressure will not impact the frame of the filter plate, which reduces the damage to the filter cloth on the frame of the filter plate. It will not impact the filter plate to cause vibration, and the small flow and high pressure in the later filtration stage are not easy to cause the pump to hold back.
Since this type of pump has a steeply falling working characteristic curve, it can well meet the operating conditions of the filter press and is more consistent with its working cycle. If you choose other types of products, although the basic parameters meet the requirements. However, in actual operation, problems such as broken shafts of the pump are prone to occur. As a result, the operation of the coal washing system is unstable, and the service life of the flow-passing parts of the slurry pump is relatively short.
When the top pressure force works during the feeding process of the filter press, it must quickly reach the peak value of the feeding pressure. To prevent material and air leakage, it is best to use high-pressure and wear-resistant alloy mechanical seals when necessary. After optimizing the configuration of high-quality precision mechanical seals, it is possible to carry out feeding and smooth operation in a more stable and stable state.
2. Selection of performance parameters
After the pump type is determined, the lift and flow rate is the basis for selecting the pump size and whether it is connected in series. To transport high-concentration and highly abrasive slurry, it is generally not to use high pump speed nmax (high speed of multiple speeds in the performance curve), and it is more appropriate to choose a speed of about 3/4nmax. When the selected pump is at 3/4 nmax, the flow rate is appropriate but the lift cannot be reached, so multiple pumps can be connected in series.
The flow range is also limited. For high-concentration and strong-abrasive slurry, the flow rate should be within 40-80% of the flow rate corresponding to the pump’s high efficiency. For low-concentration abrasive slurry, the flow rate should be selected within 40%-100% of the flow rate corresponding to the pump’s high efficiency. Generally, it is not selected within the range of 100%-120% of the flow rate corresponding to high efficiency.
(1). Always follow the selection principle of “rather big than small”, which is precisely the hidden danger that causes the abnormal operation of the feed pump of the subsequent filter press.
(2). The maximum flow the user (designer) provides cannot be used as the flow rate for model selection. It is necessary to fully communicate with the designer, and determine the flow basis for the selection in combination with the filter area of the configured filter press.
(3). Consistent with the working characteristics of the filter press. It is required that when the pump starts to feed, the pressure (head) is low, but a large flow is required to fill the cavity of the filter press. When the pressure is maintained, the flow rate is not needed, and a higher pressure (head) is required to discharge the water at this time.
3. Determine the required head value
(1). When selecting the filter press feed pump, the user or designer often specifies a pressure value. At this time, it is necessary to fully communicate with the user or designer, whether the value provided is the gauge pressure value or the clean water value.
(2). The filter press has specific requirements for filtration pressure. In most cases, this value is the gauge pressure value, and the gauge pressure value should be converted into the height of the liquid column (clear water value).
4. Select the appropriate transmission mode
(1). After selecting the appropriate type of feeding pump according to the appropriate type and parameters. It should be considered that the transmission form adopted by the feed pump should have two forms direct and indirect transmission.
(2). On the one hand, the working characteristics of the feed pump are considered; on the other hand, the flow-through parts for conveying clean coal slurry have a longer service life. Most feed pumps use indirect transmission.
(3). If the funds allow, the best transmission method is to use a direct transmission with frequency conversion speed regulator.
The feed pump of the filter press is a low-speed large-channel pump designed for transporting slurry with large particles of sand and gravel. Its structure adopts axial inlet and radial outlet to ensure that large sand and gravel particles are thrown out immediately through the open impeller after entering the pump chamber. It will not cause wear or particles to be stuck between the impeller, pump cover and pump body due to staying in the pump cavity. To make up for the effect that the general centrifugal pump cannot achieve.
Filter press feed pump application
This series of pumps can transport various solid-liquid abrasive slurries at 80°C or be used as a pressurized feeding pump for different filter presses. For example: non-ferrous metals such as zinc, copper, cobalt, nickel, manganese and other wet smelting processes are equipped with filter presses or process pumps. Slurry delivery pumps in mine beneficiation and non-metallic mineral processing (titanium dioxide, kaolin, etc.) or coal washing Fcentrplants. Sludge, waste residue in environmental protection industry and filter press pump or pressure conveying pump in production process.
The pump is configured for the filter press, and its main function is to supply the feed to the filter press. When the filter chamber of the filter press is filled with pulp, it must work to maintain the pressure in the filter chamber. The water in the pulp is further separated from the granular material until the amount of filtrate in the filter is reduced to a minimum. That is when the moisture in the filter cake of the filter equipment can not be reduced under the pressure that the equipment can withstand, the moisture content of the filter cake can no longer be reduced. The filter has completed the filtering stage and enters the unloading stage. In the time distribution of this filtration stage, the time for the pulp to fill the filter chamber is only a short time. And it takes a long time to maintain the pressure of the filter chamber, during which the pump’s flow rate is extremely small. The main purpose is to maintain the pressure of the filter chamber of the filter press, so that the slurry material can be separated from solid to liquid.
Advantages of Walker filter press feed pump
- Hydraulic design, novel structure design, high efficiency, corrosion resistance, stable and reliable operation;
- In the early stage, the feeding flow rate is large and the pressure is low; In the later stage of pressing, the flow rate is small and the pressure is high;
- The shaft seal is simple and reliable, no water injection, no mechanical seal, no leakage;
- The non-leakage filter press pump is more convenient to operate, easy to maintain, and has a long service life. The parts made of high-quality materials are also not easy to damage.
The material of the Walker slurry pump supporting the filter press is cast with high chromium alloy material, which has good wear resistance. The pump’s performance curve is excellent, and it is specially matched with feeding equipment such as plate and frame filter press. Its effect, the anti-blocking property of dirt, no leakage and the stability of the whole machine is deeply loved and praised by customers, which improves the working conditions of users and plays a positive role in promoting the production link. When the filter press is fed, the resistance should be changed to achieve the purpose of large flow, low-pressure feeding and low flow, high pressure filtration. Contact us get the price!