When a mixed solution of solutes flows over the membrane surface, the solvent and small molecule solutes (such as inorganic salts) will pass through the membrane. Small molecule solutes are trapped by the membrane due to their large volume and pore size, and are recovered as concentrated solutions. Therefore, the purpose of purifying, separating, and concentrating the original liquid is achieved. ultrafiltrationReclaimed water reuse equipmentThe molecular weight of the intercepted solute is I1000~500.00 daltons or the solute diameter is 0.0005~0.1um. It can almost intercept bacteria, heat sources, viruses, and gels in the solution. The ultrafiltration separation process is a sieve separation process that is related to the size of the membrane pores. It is driven by the pressure difference on both sides of the membrane and uses the ultrafiltration membrane as the filtration medium. That is, under a certain pressure, when it contains small molecular particles, proteins, large organic molecules, etc.

Characteristics of ultrafiltration water reuse equipment:

1. Separation is carried out at room temperature and low pressure, resulting in low energy consumption and low operating costs of the equipment.

2. The equipment has a small volume, simple structure, and low investment cost.

3. The ultrafiltration separation process is just a simple pressurized transportation of liquid, with a simple process flow and easy operation and management

4. Ultrafiltration membrane is a uniform continuous body made of polymer materials, which is filtered by pure physical methods. There is no qualitative change in the material separation process, and no impurities will fall off during use,

Stable operation ensures the purity of the ultrafiltrate.

Design points for ultrafiltration water reuse equipment:

1. The application scope of ultrafiltration systems is wide, and different application fields have different process flows and ultrafiltration membrane characteristics. Therefore, when designing an ultrafiltration system, the first step is to determine the application purpose and conditions of the ultrafiltration system.

2. Under a certain pressure, when the original liquid flows over the membrane surface, the many small pores densely distributed on the membrane surface only allow water and small molecular substances to pass through and become permeate, while substances with a volume larger than the micropores on the membrane surface in the original liquid are trapped on the inlet side of the membrane and become concentrate, thus achieving the purpose of separating and concentrating the original liquid.

3. The use of PSPP ultrafiltration membrane technology with different cut-off molecular weights for the separation and concentration of enzyme reagents, chondroitin sulfate, amino acids, peptides, fruit juice, animal and plant extracts, polysaccharides, glycerol, biological fermentation preparations, traditional Chinese medicine, proteins and other materials not only has no environmental pollution and saves manpower and material resources, but also does not require heating and operates at low temperatures without damaging the structure of the above substances, ensuring the original flavor of the materials and saving energy consumption.

4. Characteristics of membrane concentration and separation:

Separation and concentration are carried out at room temperature and low pressure, resulting in low energy consumption and lower operating costs of the equipment.

The equipment has a small volume and simple structure, so the investment cost is low.

The membrane separation process is just a simple pressurized transportation of liquid, with a simple process flow and easy operation and management.

The membrane, as a filtering medium, is a homogeneous continuum made of polymer materials. It is filtered purely by physical methods, and the substance does not undergo any qualitative changes during the separation process (i.e., it does not affect the molecular structure of the material).

Determination of water production of ultrafiltration water reuse equipment:

In general, the water production of ultrafiltration devices gradually decreases with the extension of operating time. When it drops to a certain extent, there will be a relatively stable period. During this period, although the water production still has a downward trend, it can basically return to a relatively stable value after cleaning. Therefore, the water production of ultrafiltration membranes should be divided into initial water production and stable water production. The water production claimed by manufacturers generally refers to the initial water production.

It is generally believed that in the design of ultrafiltration systems, a certain margin is often reserved based on the design water volume, raw water quality, and usage conditions of the ultrafiltration system, calculated according to the water flux of the ultrafiltration membrane. In areas with poor raw water quality, a larger margin is also reserved.

1. The effect of temperature on water production:

The effect of temperature on the water production of ultrafiltration systems is quite significant. As the temperature increases, the activity of water molecules increases and viscosity decreases, resulting in an increase in water production. On the contrary, the water production decreases, so even for the same ultrafiltration machine, there is a significant difference in production between winter and summer. The relationship between temperature and water production is shown in Figure 31.

Generally, under allowable temperature conditions, the temperature coefficient is about 0.0215/1 degrees, which means that for every 1 degree increase in temperature, the corresponding water production increases by 2.15%. Therefore, the method of adjusting water temperature can be used to achieve stable and consistent water production in ultrafiltration systems.

2. The impact of operating pressure on water production:

In the low-pressure section, the water production of the ultrafiltration membrane is directly proportional to the pressure, that is, the water production increases with the increase of pressure. However, when the pressure value exceeds 0.3 MPa, even if the pressure increases again, the increase in water production is very small. Therefore, in practical operation, the working pressure should be less than 0.3 MPa, otherwise the ultrafiltration membrane will rupture when the pressure exceeds the maximum pressure resistance value (0.6 MPa) of the ultrafiltration membrane.