The importance of a satisfactory homogenizer for a production line is self-evident, because it is the key to product output, quality, and cost-effectiveness, and also affects the normal operation of the entire production line. The conditions for selecting a satisfactory homogenizer should have sufficient flow , Stable pressure, good homogenizer effect, durable wearing parts, low noise, energy saving, fuel saving, convenient operation and maintenance, etc. Combined with the scale of the project, product category and production process, comprehensively consider and select the most satisfactory homogenizer, and the following main technical parameters should be grasped in practice.
1. Traffic
The unit is expressed in L/h, which means that the production flow rate is not less than the data indicated on the nameplate. Even when the pressure reaches the maximum value, the flow rate is not less than the data indicated on the nameplate, so as to ensure the design requirements and normal operation of the production line. Under the condition of sufficient feed , the flow data provided by the manufacturer can be obtained by the following calculation method:
Q=d2/4×π2e×Vn×n×60×K/1000 L/h
In the formula:
d: plunger diameter, expressed in cm
π : 3.1416
2e: plunger stroke (e is crankshaft eccentricity), expressed in cm
n: the number of plungers
Vn: plunger speed, expressed in r/min
K: flow coefficient
The size of the flow coefficient K in the formula is determined by the structure, material, sealing material and sealing method of the homogenizer itself, as well as the machining accuracy. External leakage leads to too low K coefficient, resulting in congenital insufficient flow, resulting in excessive loss of long-term output benefits to users.
For this reason, the homogenizer equipment provided by the manufacturer needs to have a reasonable structure, excellent material, professional sealing and good processing conditions to achieve it.
In practice, to determine the flow rate, if there is no flow meter at hand, the easiest way is to use the weighing estimation method, that is, when the homogenizer is running at the rated pressure, use a bucket to receive the material (or use water instead) and weigh it for one minute. Multiply by 60 to get the hourly flow. For example, Shenlu Homogenizer SRH10000-35, when the rated pressure is 28MPa, the measured water weight per minute is Q=167kg. SRH5000- 30 has a rated pressure of 24MPa, and the measured water weight Q=84kg per minute.
2. Pressure
Unit: Expressed in MPa, Bar, Psi. The value 1MPa≈10Bar≈145Psi is often marked on the nameplate of the homogenizer with the maximum working pressure (or maximum test pressure) expressed in Pmax. Also marked with the rated working pressure (continuous production pressure) with P said. In production practice, high-pressure homogenizers often advocate light-load work, and the rated working pressure is P=0.8Pmax.
For example: the maximum pressure Pmax25MPa, the rated production pressure should be P≤20MPa is appropriate. That is to say, pay attention to the required production pressure when selecting the model and leave room for it, and the pressure gauge indicates that the swing range is ≤0.5MPa. Under the rated working pressure, as long as the process requirements are met and the quality is guaranteed, it is very beneficial to take a low pressure value to reduce energy consumption and prolong the service life and maintenance cycle of wearing parts.
3. Homogenization effect
For the plunger pump high-pressure homogenizer, the key component of the homogenization effect is the high-pressure homogenization valve. Under the same pressure, its structure, flow channel, and material of the valve determine the homogenization effect, which is also determined by the manufacturer's design. However, under high pressure conditions, the working end faces of the valve seat, valve stem, and collision ring of the homogeneous valve are easily eroded, and the processing and manufacturing are relatively difficult, and the cost is also high. For this reason, the shapes of high-pressure valve seats, valve cores, collision rings and other parts need to be simple during model selection to facilitate processing, especially for manufacturers who can easily repair them for reuse. At present, high-pressure homogeneous valves generally use flat valves for this reason. Pay attention to the selection.
To determine the homogenization effect, generally two parameters need to be determined for milk, one is the particle size, and the other is the proportion of particles that reach the same particle size. According to the proportion of fat globules that reach the same particle size after homogenization, the effect of the homogenizer can be evaluated. Bad, when the fat globule diameter!: less than 2 μm reaches more than 98%, the homogenization effect is excellent; fat globule diameter!: less than 2 μm, less than 98%, and when it is less than 2.5 μm, higher than 95%, the homogenization effect is good; if When the fat globule diameter is less than 3 μm and less than 90%, the homogenization effect is poor, that is, the homogenization performance is not good.
The most intuitive method to judge the homogenization effect is the microscope method. Generally, an optical microscope is used at 1000x or other appropriate magnifications, and the fat globules are directly measured in the field of view with the micrometer of the eyepiece or the spiral micrometer. Figure 3
4. Noise
Expressed in decibels db, the noise level is closely related to the equipment structure, processing accuracy, and installation conditions. There is no national standard in the homogenizer industry. The Shenlu homogenizer is placed in front of the main pump body with a decibel meter according to the municipal enterprise standard. Measured at the meter, it is more satisfactory to be less than the number of decibels indicated on the nameplate of the motor.
5. Energy consumption
The energy consumption of the homogenizer is related to the structural manufacture, precision and installation of the homogenizer, and can be estimated by the following formula in practice:
N=Q×P/K ( Kw )
In the formula:
N — energy consumption, expressed in Kw
Q — hourly flow expressed in L/h
P — Selected pressure, represented by Bar
K—efficiency coefficient (each manufacturer is not exactly the same, there is K: 30060
K:31212 (The larger the K, the smaller the energy consumption)
For example: Shenlu SRH5000- 25 Q:5000L/h
P:200Bar K:31212
N=5000×200/31212=32Kw
Ammeter indicates 64A±10%
It is a very useful reference data for model selection and reasonable electrical matching.
6. Consumable parts
The wearing parts of the homogenizer are mainly valves, seals, plungers and so on. Due to the different materials and processing techniques, each manufacturer is exactly the same. For the selection of equipment, only comparison can be made to choose the best.
7. Suitable for the whole process of CIP disinfection
Valves, plungers, seals, ejector rods and other parts that come into contact with food need to meet the requirements of NaOH 1.5~2%, HNO 3 1.5%, 85°C.
