When the upstream installation conditions are limited and the above requirements cannot be met, it is recommended that special tests be conducted to understand the effect of the installation conditions on the uncertainty of the flow measurement and/or the effect of the installation conditions on the determination of the outflow coefficient Cd for the initial verification. This standard gives a correction method for calculating mass flow under p>o.25. 2. If there is a large space upstream from the primary device axis or the primary device population plane, see JJG 620-2008 [Section "Structure Type" in this section. Trumpet throat venturi nozzle (1), or see 2. Cylinder-throat critical flow venturi nozzle] Where there is no tube wall within 5d, it can be considered that the upstream of the primary device is a large space. In the case of large upstream spaces or for large flows, multiple J critical flow venturi nozzles can be used. 3. In addition to downstream requirements, critical flow venturi nozzles should not be allowed to reach critical flow, and there are no other requirements for export pipelines. 4. Drain hole The pipe can be equipped with the necessary drain holes to drain condensate or other impurities that may collect in some applications. When measuring flow, no fluid should pass through these drain holes. If drain holes are required, they should be set upstream of the pressure inlet on the upstream wall of the nozzle. Drain hole diameter should be less than o. 06D. The axial distance from the drain hole to the outlet port of the upstream pipe wall should be greater than D, and the drain hole should be located on a different axial plane than the axial plane of the pipe wall. At the time of measurement, the upstream and throat flow should be single-phase flow and non-condensing, and all inner surfaces must be kept clean to maintain their surface finish.
Product Features:
1) All the electrical components of the
Sushi Packing Machine adopt imported products. The main components are made of
stainless steel and food hygienic plastic. The structure is reasonable, the
operation is convenient and the operation is stable and safe.
2) The machine packaging sushi rice balls,
the process of mechanization completely manual without the opportunity to
automatically complete rice ball molding, plastic film packaging the entire
process. Produced rice balls, the surface smooth, beautiful shape, uniform
volume, in full compliance with national health and epidemic prevention and
other testing standards.
Sushi Packing Machine Sushi Packing Machine,Automatic Sushi Packing Machine,Vertical Sushi Packing Machine,Film Sushi Packaging Machine Guangzhou QianYu Food Machinery Co., Ltd. , https://www.qianyusushimachinery.com
The principle of venturi flowmeter is that when the wind blows over the barrier, the air pressure near the port above the leeward surface of the barrier is relatively low, thereby generating adsorption and leading to the flow of air. The principle of the Venturi tube is actually very simple, it is to make the air flow from coarse to fine, in order to speed up the gas flow rate, so that the gas in the Venturi tube back to form a "vacuum" zone. When this vacuum zone is close to the workpiece, it will have a certain adsorption effect on the workpiece.
Compressed air enters from the inlet A of the venturi and a small part is discharged through the nozzle B with a very small cross-section. As the cross section gradually decreases, the pressure of the compressed air increases, and the flow velocity also increases. At this time, a vacuum is generated in the inlet of the D adsorption chamber, so that the ambient air is sucked into the Venturi tube, and the compressed air flows into the diffusion chamber to increase the gas flow rate, and then the air flow is reduced by the muffler device.
The vacuum generator is a new, efficient, clean, economical, small-sized vacuum component that uses a positive pressure gas source to generate negative pressure. This allows positive and negative pressures to be required in the presence of compressed air or in a pneumatic system. It is very easy and convenient for locals to obtain negative pressure. Vacuum generators are widely used in industrial automation in machinery, electronics, packaging, printing, plastics and robotics. The vacuum generator's traditional use is suction cups for adsorption and handling of various materials, and is particularly suitable for the adsorption of fragile, soft, thin non-ferrous, non-metallic materials or spherical objects. In this type of application, a common feature is that the required amount of suction is small, the degree of vacuum is not demanding, and intermittent operation is required.