Dec 07,2022

How to install a negative-pressure fan to achieve a good ventilation effect

When installing a negative-pressure fan, it is crucial to ensure high-quality installation, paying particular attention to eliminating any gaps around the fan. During the installation of a negative-pressure fan, it is best to close all surrounding doors and windows; however, doors and windows on the opposite wall should be left open to allow for air circulation. The proper installation of negative-pressure fans is extremely important and directly affects their subsequent performance.

Dec 07,2022

Precautions when installing and using a negative-pressure fan:

It is preferable to install a negative-pressure fan in the middle of the building's interior space, close to areas where high temperatures, stuffy heat, as well as concentrated smoke and odors are generated. If possible, install it at the upper part of the prevailing wind direction in the cooling environment. The fan can be mounted on interior walls, windows, roofs, and internal load-bearing columns. However, it is important to note that the installation conditions must ensure unobstructed intake of fresh air; in particular, the fan must not be installed in exhaust areas from which odors or harmful gases are discharged. If there are insufficient doors or windows, it is necessary to install a dedicated air supply system, with the volume of supplied air exceeding the total volume of air drawn in by the negative-pressure fan by 100–150%.

Dec 07,2022

The wood drying process involves three distinct stages:

The first stage involves removing water from the surface of the wood; this can be accomplished by drainage or other external mechanical forces (centrifugal force, pressure). However, this method allows only the removal of free water from porous wood. Another mechanism is evaporation, in which free water is present within the wood cells in a manner similar to capillary systems.

Dec 07,2022

Agricultural rice dryers employ several drying methods.

The operating principle of agricultural dryers is similar; however, the drying process itself may vary, primarily because the moisture content of rice harvested in different regions and at different times can fluctuate. The appropriate drying process should be selected based on the condition of the grain. There are four main drying processes for agricultural dryers, namely:

Dec 07,2022

What is the operating principle of a rice dryer?

A rice dryer is a mechanical device used to dry rice. It employs heat and wind to dry the rice that is loaded into the machine. What exactly is the operating principle of a rice dryer? The rice dryer uses a special type of heat pump to generate heat! A fan provides the heat source for the rice dryer. The evaporator absorbs heat from the outside air and then transfers it to a refrigerant gas that has been compressed to high temperature and pressure. This high-temperature, high-pressure gas then flows into the condenser, where it releases its heat to dry the rice inside the dryer. The heat source is carried by the refrigerant, which gives off heat at the condenser. After passing through a thermostatic expansion valve, the refrigerant returns to the evaporator, and the cycle repeats in this sequence, ensuring continuous drying.

May 16,2018

Precautions when servicing the circulation fan

Proper maintenance is a crucial guarantee for the safe and reliable operation of a circulating fan, and it also helps extend its service life. Therefore, when using circulating fans for tobacco processing, it is essential to pay adequate attention to them. At the initial stage of impeller operation and during all routine inspections, whenever possible, the impeller should be examined for defects such as cracks, wear, and dust accumulation. Whenever feasible, the impeller must be kept clean and regularly brushed with a wire brush to remove dust and rust deposits. Over time, this accumulated dust may settle unevenly on the impeller, disrupting its balance and causing rotor vibrations. After repairing the impeller, it must be dynamically rebalanced. If conditions permit, a portable balancing device can be used to perform balancing directly on-site. Before conducting dynamic balancing, it is necessary to check that all fastening bolts are properly tightened. "Since the impeller has been operating in an unbalanced condition for some time, these bolts might have become loose." Apart from regular inspections of the internal housing and suction chamber for severe wear and removal of heavy dust deposits, no additional special repairs are required for these components. Regularly verify that all fastening bolts are securely tightened. In fans equipped with compression bolt assemblies, press the butterfly spring on the support until it reaches the installation level indicated in the drawing. During bearing unit maintenance, the supply of lubricating oil to the bearings is often checked. If oil leakage is observed in the housing, slightly tighten the bolts on the end cover. If this does not suffice, it may be necessary to replace the sealing gasket with a new one. Maintenance of other auxiliary equipment, including motors, electric drives, instruments, and measuring devices, is described in detail in their respective operating manuals. These manuals are provided by various manufacturers of auxiliary equipment, and our manufacturer will deliver these manuals to users in random packaging. Repair and maintenance of high-temperature circulating fans when they are out of service: When the fan is not in use and the ambient temperature drops below 5 ℃, any residual water in the equipment and piping should be drained to prevent damage to the equipment and piping due to freezing. Maintenance of tobacco-processing circulating fans operated by smoke drying during prolonged shutdowns and storage: Cover the surfaces of bearings and other critical components with an anti-corrosion oil to prevent corrosion. The rotor of a high-temperature circulating fan used for tobacco processing should be manually rotated by half a turn (that is, by 180°) approximately every two weeks. Before rotating the rotor, the end of the shaft should be marked so that the original top point becomes the bottom point after the rotor is moved.