Now the factory building is hot in summer and cold in winter. Because of its large area and dense staff, the equipment in it will produce a lot of heat and noise, as well as the dirty air that endangers people's health. So how to solve this problem? That is to install roof natural ventilators on the roof of our factory building, How to select and install the roof natural ventilator in the workshop (as shown in the figure below is the selection parameter table of the roof natural ventilator)

Exhaust parameter table of roof natural ventilator

The design and working principle of the roof natural ventilator mainly revolves around the aerodynamic wind load type theory "when the wind acts on the object, the windward side is the pressure, and the leeward side is the suction along the wind direction". At the same time, combined with the structural mechanics of buildings, through numerous tests and improvements, it has formed a relatively perfect ideal product for daylighting and ventilation.

1、 The performance of roof natural ventilator is mainly reflected in the following aspects:

1. The overall design is streamline arc type, which not only ensures the strength of the ventilator body, but also effectively reduces the wind pressure of the ventilator body;

2. The large volume formed by the height and arc of the ventilator can effectively improve the collection and emission capacity of indoor air;

3. Set up booster air trough ( It's also a drain ) The whole roof is transformed into a wind collecting platform to gather the wind force on the roof, form a wind pressure thrust from the bottom to the top on the ventilator, and drive the air in the heat accumulation bin to discharge upward;

4. Any direction of the wind over the top of the ventilator is bound to form a suction on the outlet, improve the ventilator pull-up speed.

2、 Structure and dimensions of roof natural ventilators

Roof natural ventilator (commonly known as gas building) is mainly composed of the following parts: roof natural ventilator framework, rain shield, valve plate and electric opening mechanism ( Whether to use the motor opening mechanism is determined by the user's needs )、 Drainage ditch, flashing board, external maintenance board.

According to the throat width a, the ventilation skylight can be divided into seven types; According to different values of wind load, each type can be divided into three specifications, with a total of 21 specifications. The main dimensions are shown in the table.

The product adopts electric opening mechanism ( Whether to use the motor opening and closing mechanism is determined by the user according to the needs ) The opening mechanism is composed of motor, reducer, transmission mechanism, etc. the switch control can be installed at the place convenient for operation.

2、 Selection of natural ventilators on roof

It can be selected by formula calculation or by looking up the table directly. The following two selection methods are introduced respectively.

1. Formula calculation and selection method:

During the calculation, the required exhaust air volume should be calculated according to the heat dissipation during production, plant height, indoor and outdoor temperature and other factors, and then the throat width and length a and l of ventilation skylight should be determined.

TC type ventilation skylight can be calculated according to the following formula:

A ρ ——Ventilation skylight exhaust area

G ρ ——Exhaust air volume

G -- acceleration of gravity

P ρ ——Air density of vent of ventilation skylight

Δ h -- the height from the top of the ventilation skylight to the neutral boundary, M

PW -- air density at air inlet kg / m3

P ρ ——Average indoor air density kg / m3

Pnp = pn + pp／ ( Simplified value ) PN -- air density of indoor working face, kg / m3

ξ ——Local resistance coefficient of ventilation skylight outlet TC type ventilation skylight = 1．68

The shape of roof natural ventilator is arc-shaped combined type. It is a new generation of ventilation product developed by Zhengxin after in-depth research and Discussion on domestic similar products and absorbing the advanced technology of international similar products. In order to reach the international leading level, the multi working condition optimization test has been carried out on the air flow structure, and the structure has been optimized and improved for many times. The arc-shaped combined roof ventilator is an ideal retrofit product for natural ventilation of high heat plant.

The roof natural ventilator has the outstanding advantage of low exhaust resistance and is a good natural ventilation equipment. In addition, the roof ventilator structure also has good rain and snow proof and wind shelter performance, any direction or wind size will not affect the exhaust effect of the roof ventilator, so there is no need to set another wind shield.

Selection of natural ventilators on factory roof

The throat of roof natural ventilator is equipped with electric valve plate, which can be opened flexibly and closed tightly. The valve plate opens in summer. It has the function of diversion to ensure good ventilation effect; Close tightly in winter to ensure the normal operation of the heating system according to the design. If the moisture content of the workshop is high, the heat preservation measures can be taken for the enclosure board of the roof ventilator throat to prevent condensation.

Product features and uses of roof natural ventilators:

The outer guard plate of roof natural ventilator is made of color metal profiled color plate, which has the characteristics of light weight, on-site combined installation and short construction period. Roof ventilators can be widely used in power, metallurgy, chemical, petroleum, machinery and other industries of all kinds of plant ventilation and ventilation.