Aluminum frame, rainproof mesh, and a galvanized steel wire mesh distribution structure. The outer frame and louvers of the rainproof shutter are made of aluminum alloy with silver-white oxidation; the louver cross-section features a streamlined design to reduce wind resistance, and the louver thickness is 1 mm.

Standard size:

Width (mm) mm = 456 + 152 × N

Height (mm) H = 456 + 152xN

We can custom-make various sizes upon request.

Aluminum-reinforced galvanized steel frame with plastic bearings; the baffle is designed for双向 operation and features sealing strips on the sides. The outer frame is made of 1.5mm hot-dip galvanized sheet metal; the blades are silver-white oxidized aluminum alloy, 2mm thick; the ear shafts, connectors, and adjustment handles are made of high-strength plastic.

 

Standard size:

Width (mm) mm = 456 + 152 × N

Height (mm) H = 456 + 152xN

We can custom-make various sizes upon request.

Air supply outlet

 

- Air diffuser with guide vanes

 

There are many different types of air supply outlets, and we offer more than a dozen varieties, such as louvered air supply outlets, diffusers, spherical air supply outlets, and more.

Here, we’d like to highlight the diffuser air outlet with a guide vane. This outlet is made of sheet metal and consists of four steel guide vanes, designed for low-induction airflow. It’s ideally suited for installation beneath ceiling panels. The box-shaped diffuser hood, equipped with an adjustable damper, connects the guide vane to the ductwork. Inside the box, there are adjustable blades that allow precise control of the airflow volume.

Aijin is one of the domestic companies that have adopted this air outlet. Experience has shown that this air outlet boasts broad adaptability and delivers excellent airflow performance.

 

Article-No.	Specification	Picture display
According to the drawing	Diffusion air outlet Common sizes 625x225xh 825x225xh 1025x225xh 1025x325xh
0064.5601	Air deflector W=225, L=2500
0064.5602	Air deflector W=225, L=2500

 

Features of the Small-Scale Air Supply System

The small-environment air supply system is also known as the loom-local air supply system or the microclimate air-conditioning system for weaving areas. The emergence of this air-conditioning system is primarily driven by the following factors:

(1) Further improvements in weaving machine productivity, coupled with the resulting increase in energy consumption per machine, have led to air exchange rates exceeding 30 air changes per hour.

(2) The requirements for product quality are continuously increasing;

(3) Energy consumption costs continue to rise;

(4) Harsh workshop conditions and high humidity make it difficult to recruit workers.

Therefore, the stricter requirements for advanced air-conditioning systems aim to minimize investment costs and energy consumption as much as possible, while simultaneously enhancing workshop cleanliness and comfort. This has led to the emergence of small-environment air-conditioning systems. This new type of air-conditioning system primarily relies on directly delivering conditioned air onto the surface of the warp yarns, thereby improving the microclimate around the weaving area. It represents a method for boosting both economic and energy efficiency, fully taking into account the ongoing rise in energy prices.

 

The changes in temperature and humidity in the weaving area depend not only on the structure of the loom but also on the following three factors:

1. Local heat sources and the resulting thermal effects, such as the weft-insertion principle, the location of the main drive motor, and the position of the weft storage device;

2. The relative position of the loom within the airflow;

3. The upward airflow caused by the reciprocating motion of the reed.

Processing problems caused by fluctuations in temperature and humidity, as well as the formation of fiber fluff and dust, can be significantly mitigated by supplying conditioned air to the work area. Therefore, the guiding principle behind the design of small-scale environmental air-conditioning systems is to treat the weaving area as the primary focus of air conditioning, creating localized microclimatic conditions within the weaving zone. This approach enables achieving the temperature and humidity levels required for weaving processes with minimal energy consumption, thereby reducing fiber fluff and dust to a lower level.

 

The system delivers conditioned air directly into the shed area of the warp yarns, thus achieving better performance in terms of both investment and energy consumption. The key features of the air supply are as follows:

(1) Moist air is delivered uniformly through a specially designed air supply device in a flow condition that approximates laminar flow with low turbulence. This nearly turbulence-free supply airflow prevents mixing with the dry air surrounding it within the workshop.

(2) It can also prevent surrounding fibers, fluff, and dust from contaminating the supply air flow.

(3) The warp layer can be achieved with lower moisture loss. Since there is a humidity difference between the supply air’s humidity and the workshop’s humidity, a vapor pressure difference is created. This causes the water vapor in the supply air stream to penetrate deeper into the yarn more rapidly.

(4) The airflow creates a deflection along the warp direction, completely enveloping the warp yarns to protect them from the effects of the workshop environment.

 

This new air-supply method ensures that the conditioned air remains in close contact with the warp yarns, while also directing most of the fine dust generated on the warp yarns toward the exhaust vents, thereby reducing the spread of dust and impurities throughout the workshop. After the warp yarns leave the humidification zone and proceed toward the weft-insertion area, they will release some moisture. By the time they reach the weaving zone, their moisture content will have reached an optimal level, perfectly meeting the requirements of the weaving process. The relative humidity in the workshop is generally maintained at around 60%. To enable operating personnel to find a suitable setting for each loom, the flow rate of the conditioned air can be adjusted within a certain range.

When the loom stops, the supply air flow can be automatically or manually shut off.

If the blower is controlled by a variable-frequency drive, the airflow of the blower will automatically decrease when the air outlet is closed.

If the supply fan is fixed-frequency, the air-conditioning system must be equipped with a bypass duct to automatically return any excess supply airflow back to the air-conditioned room.

A regulating valve must be installed on the supply air branch of the small environment system.

In fact, standalone small-environment air conditioning systems are currently used relatively infrequently, and such systems typically require additional heating devices.

 

Local air supply outlet

There are typically three types of air supply outlets. The appropriate outlet can be selected based on the specific conditions of the project. The air velocity at the outlet should be maintained between 0.4 and 0.8 m/s, and a suitable filter mesh should be chosen according to the type of fabric being produced.

(1) FKX-type air outlet (suitable for downward air supply)

(2) FKH-type air supply outlet (connected via round duct or flexible hose, suitable for downward air supply)

(3) AK-type air supply outlet (with direct connection of the supply duct opening)

 

FKX-type air outlet

The simplified diagram of the air supply outlet is shown below. The outlet consists of components such as a mesh panel, a filter screen, a flow-distribution plate, and an adjustable damper.

 

 

 

Schematic diagram of downward air supply from an FKX-type air outlet

1—FKX-type air outlet; 2—warp beam

 

The air supply outlet has a width of 120 mm and is connected to the main air supply duct via a 125-mm-diameter circular pipe. The outlet comes in various lengths, and the specific airflow rates are shown in Table 3.1.

 

Airflow range of the FKX-type air outlet

Vent length	Airflow range
mm	min m³/h	max m³/h
1300	320	650
1400	350	710
1500	380	760
1600	400	810
1700	430	860
1800	450	910
1900	480	960
2000	500	1010
2100	530	1060
2200	550	1110
2300	580	1160
2400	600	1210
2500	630	1260

 

Airflow rate of FKX-type air diffuser

 

 

FKX-type air outlet resistance

 

Key selection points for FKX-type air outlets:

(1) It should not be used in a standalone, small-scale environmental system; in other words, the underfloor air distribution system must be used in conjunction with a larger, overall ventilation system. This is because using an underfloor air distribution system on its own would result in insufficient airflow in the workshop and inadequate cleanliness within the workshop.

(2) The length of the air outlet typically exceeds the width of the loom by 100 mm. If the loom’s width exceeds 240 cm, it is necessary to use a combination of two or more air outlets. For example, if the loom’s width is 250 cm, you can combine two FKX-type air outlets, each with a length of 1300 mm.

(3) Not all looms have sufficient space to install FKX-type air outlets—this is extremely critical, so be sure to confirm this before designing.

(4) The main supply duct can either run through a trench or be routed above the ceiling, connecting directly to the air diffusers via circular supply ducts or flexible hoses.

(5) The regulating valve with a diameter of Φ125 can be operated either manually or automatically, depending on the customer’s preference. If automatic control is selected, when the loom stops, the air supply outlet for that loom will also close automatically. Once the outlet closes, the air pressure within the duct will rise, and accordingly, the air supply unit will automatically reduce its air delivery rate.

(6) The air outlet must be securely fixed to the loom’s frame.

  

Advantages:

(1) Direct air supply through the warp yarn surface—its advantages have already been explained in the preceding text.

(2) The air outlet and the loom are integrated into one, with no visual obstructions;

(3) Improve the efficiency of loom operation

(4) If the loom does not stop, the annual air supply remains essentially constant, making adjustment and management straightforward.

(5) Low air volume, low water spray rate, energy-saving, and low equipment investment.

     

Disadvantages:

(1) Compared to conventional central air conditioning systems, additional costs are required for air vents and installation.

(2) There are not many loom models suitable for installing this air outlet.

(3) The air supply volume should not be large; the maximum air volume for each air outlet should not exceed 800 m³/h.

(4) Compared to other types of localized air supply outlets, this air supply outlet has higher resistance. In practical applications, the resistance should not exceed 200 Pa.

(5) The rising airflow causes flying fibers and dust particles to easily disperse, making it particularly unsuitable for use in denim weaving workshops.

(6) Since this system cannot be used independently, a separate ambient air supply system must also be installed and controlled separately.

(7) Dust tends to accumulate on air vents, especially when the loom has been idle for a long time. The air vents must be cleaned before they can be used again.

 

Attention:

The underfloor air distribution method is typically used only for blended fabrics, pure polyester fabrics, polyester-viscose fabrics, and other synthetic fiber fabrics.

 

The application of downward air supply and the principle of displacement ventilation:

As an energy-efficient ventilation method, displacement ventilation has already achieved significant development in civil buildings. Its unique airflow organization not only ensures good air quality and effectively removes pollutants, but also delivers substantial energy savings—particularly in industrial enterprises, where energy consumption is typically very high. Displacement ventilation is generally suitable for use under two common conditions:

(1) The machine generates significant heat, for example, in an air-jet spinning workshop.

(2) The process requires a relatively high level of relative humidity, for example, in weaving workshops.

 

Advantages:

(1) Conforms to the laws of hot air flow movement

(2) Human thermal comfort is greater in a workshop with upward air supply and downward air return than in one with the opposite configuration.

(3) In the weaving workshop, there is no need to consider air temperature and humidity above human height within the workshop. In other words, only the space below 2 meters in height needs to be taken into account when calculating the workshop volume, greatly enhancing the effectiveness of the air supply.

(4) With large temperature differential air supply, both the air volume and installed power are lower than those of the upward-supply and downward-return system. The air change rate can be reduced by approximately 15% to 25% compared to the upward-supply and downward-return system, resulting in a significant reduction in energy consumption.

(5) Although the air is delivered with a large temperature difference, since the supply air outlet is directed straight toward the warp surface, the air temperature rise upon reaching the work area is not significant. This allows us to raise the supply air temperature. For example, suppose in a workshop during summer the supply air temperature difference is 7℃, and the return air temperature at the return grille is 36℃—meaning the supply air temperature is 29℃. The temperature in the work area would be around 31.5℃, while the temperature at head level of the workers would be approximately 33℃. Clearly, during most of the summer in most parts of China, simply using tap water can bring the supply air temperature down to 29℃, making the energy-saving effect immediately apparent. Even during the plum rain season, in the middle and lower reaches of the Yangtze River, well water at 22℃ can easily meet the workshop’s temperature and humidity requirements. In northern or northwestern regions with lower humidity, the requirement can be met even more easily.

In summary: Large temperature differences in the supply air and a pronounced temperature gradient significantly reduce the number of air changes required in the workshop.

(6) Reduced initial investment costs

(7) The terminal resistance is high, but the dedicated FKX-type air diffuser is equipped with a flow-rate adjustment device, making it easy to balance the airflow. The total resistance of the air-conditioning system is low.

 

Disadvantages:

(1) To ensure uniform distribution of the supply air volume, the air velocity in the ducts should not be too high—generally less than 6 m/s. However, constructing such ducts involves substantial civil engineering investment.

(2) Moist air can corrode machinery and shorten its lifespan.

(3) Installing air vents is relatively complicated; not all machines have sufficient space at the bottom to accommodate air vents.

(4) The air supply velocity is low, making it easy for dust to accumulate at the air outlets—especially when the system is idle for extended periods.

(5) Not suitable for use in workshops with a high amount of flying debris.

 

Attention:

Generally, drainage ditches should not accumulate water, as prolonged waterlogging can easily breed bacteria and lead to the buildup of waste that becomes increasingly difficult to clean over time. However, in the displacement ventilation system used in weaving workshops, a small amount of water in the drainage ditch—caused by excessive water carried by the waterstop—is sufficient to bring the supply air to a state of oversaturation. This oversaturated air is delivered to the lower part of the warp yarns on the loom. Under conditions that meet process requirements, an automatic control system further reduces the volume of supply air.

In our previous case of underfloor air distribution at the weaving mill, oversaturation of the supply air was already being employed after excessive water flow occurred due to scaling on the water baffles.

Of course, the drawbacks are obvious: the trenches are dirty, the temperature gradient within the workshop is too pronounced, machinery is subject to corrosion, and replacing filter cloths at air vents is a hassle—among other issues.

 

In summary: Currently, underfloor air distribution systems have been applied in air-jet spinning workshops and weaving workshops. Shanghai Airking Air Equipment Co., Ltd. possesses profound technical expertise in this area, and we hope that this technology will be adopted by an increasing number of enterprises.

 

FKH-type air outlet

 

The simplified diagram of the air supply outlet is shown below. The outlet consists of components such as a mesh panel, a filter screen, a flow-distribution plate, and an adjustable damper.

 

Simplified Diagram of FKH-Type Air Outlet

 

The FKH-type air diffuser comes in three models, with specific dimensions as shown in the table below:

 

FKH-type air supply outlet dimensions

 

Schematic diagram of air supply from FKH-type diffusers:

 

Schematic diagram of downward air supply from an FKH-type air outlet

1—FKH-type air outlet; 2—warp beam

 

A practical case study of the FKH-type air supply outlet for a certain project.

1—FKH-type air supply outlet; 2—small-environment air supply duct; 3—large-environment air supply (30% of the total large-environment air supply volume)

 

4—Supply air from the general environment (70% of the total supply air volume); 5—Double-warp jacquard loom; 6—Air return outlet; 7—Steel-structure platform

 

FKH-type air outlet

 

1—Small environmental air supply duct; 2—Round duct (connecting the air duct and the air outlet); 3—FKH-type air outlet; 4—Jacquard loom

 

Quick Reference Table for Airflow Rate of FKH1 Air Diffusers

 

Airflow rate of FKH1-type air supply outlet

 

Airflow rate of FKH2-type air supply outlet

 

Airflow rate of FKH3-type air supply outlet

 

 

Resistance of FKH-type air diffuser

 

Key selection points for FKH-type air outlets:

(1) Can be used in a standalone, small-scale system;

(2) The length of the air outlet typically exceeds the width of the loom by 200 mm. If the loom’s width exceeds 230 cm, it is necessary to use a combination of two or more air outlets. For example, if the loom’s width is 240 cm, you can combine two FKX-type air outlets, each with a length of 1300 mm.

(3) The height of the air outlet’s bottom from the warp yarn surface needs to be designed according to actual conditions; typically, this height ranges between 0.8 m and 1.2 m.

(4) The main supply duct can either run through a trench or be routed above the ceiling, connecting directly to the air diffusers via circular supply ducts or flexible hoses. The diameters of the circular supply ducts are available in three sizes: Φ160, Φ200, and Φ250; the appropriate size should be selected based on the actual dimensions of the air diffusers.

(5) The regulating valves used for air outlets can be either manually or automatically controlled, depending on the customer’s preference. If automatic control is selected, when the loom stops operating, the air outlet for that loom will also close automatically. Once the air outlet is closed, the air pressure within the duct will increase, and accordingly, the air supply unit will automatically reduce its air delivery rate.

The straight section of the round pipe where the regulating valve is installed should be no less than 50 cm long, to facilitate airflow adjustment and reduce resistance.

(6) The air outlet needs to be suspended above the loom via suspension rods. These suspension rods must be securely anchored to locations capable of supporting the weight of the air outlet—for example, the steel platform of a jacquard loom, the flange of the air supply duct, the ceiling joists, steel beams, or floor slabs.

  

Advantages:

(1) Direct air supply through the warp yarn surface—its advantages have already been explained in the preceding text.

(2) Suppresses flying debris and ensures high workshop cleanliness;

(3) Improve the efficiency of loom operation

(4) If the loom does not stop, the annual air supply remains essentially constant, making adjustment and management straightforward.

(5) Low air volume, low water spray rate, energy-saving, and low equipment investment.

(6) By reducing the diffusion of heat dissipation from the machinery, the machine’s heat is returned directly to the air-conditioning room via underground ducts before it has had sufficient time to fully mix with the workshop air—meaning that the cooling load (the cooling load requiring air treatment) is reduced.

(7) Compared to FKM-type air outlets, this air outlet is particularly well-suited for weaving workshops with very low ceiling heights, as the layout of small-environment supply ducts is highly flexible.

(8) Particularly suitable for workshops where it is inconvenient to directly install small environmental air ducts above looms such as double-warp looms and jacquard machines.

 

Disadvantages:

(1) Compared to conventional central air conditioning systems, additional costs are required for air vents and installation.

(2) Typically, supply air ducts are installed beneath the ceiling, creating a visually oppressive atmosphere within the workshop.

(3) Dust tends to accumulate on the supply air ducts in the microenvironment.

 

FKM-type air outlet

The simplified diagram of the air supply outlet is shown below. The outlet consists of components such as a mesh panel, a filter screen, a flow-distribution plate, an adjustment valve, a sliding outlet, and a guide vane.

 

Simplified Diagram of FKM-Type Air Outlet

 

The FKH-type air diffuser comes in three models, with specific dimensions as shown in the table below:

 

FKH-type air supply outlet dimensions

 

Schematic diagram of air supply from an FKM-type air outlet:

Schematic diagram of downward air supply from an FKM-type air outlet

1—FKM-type air outlet; 2—warp beam; 3—small-environment supply air duct

 

The air supply volume of FKM1/2/3 is the same as that of FKH1/2/3.

The resistance of the FKM-type air outlet is related to the dimensions of the sliding air outlet. The resistance curve is shown in Figure XXX, with different colors representing different sliding air outlet sizes. The resistance curve was obtained based on a wind speed of 4 m/s within the duct of the small-scale environment.

 

Resistance Curve Diagram for FKM1 Air Diffuser Type

 

Resistance Curve Diagram for FKM2 Air Diffuser

 

Resistance Curve Diagram for FKM3 Air Diffuser

 

Attention:

FKM-type air outlets have relatively low resistance; therefore, when designing air-conditioning systems, it is advisable to select these outlets whenever possible. The curves shown represent the initial resistance of the air outlets. Typically, the initial resistance is around 50 Pa, while the final resistance usually ranges from 100 to 150 Pa. Since the resistance of the air outlet continuously increases, it’s crucial to maintain a constant airflow at the supply vent. For small environments, the supply fan must be equipped with variable-frequency control, and the ductwork should include resistance sensors. When the resistance at the terminal air outlet rises, the fan speed will automatically increase accordingly. If the resistance exceeds the set value, the automatic control system will trigger an alarm, indicating that the filter element in the air outlet needs to be replaced. Of course, these automatic control measures are optional and not required for every project.

 

Key selection points for FKM-type air outlets:

(1) Can be used in a standalone, small-scale system;

(2) The length of the air outlet typically exceeds the width of the loom by 200 mm. If the loom’s width exceeds 230 cm, it is necessary to use a combination of two or more air outlets. For example, if the loom’s width is 240 cm, you can combine two FKX-type air outlets, each with a length of 1300 mm.

(3) The height of the air outlet’s bottom from the warp yarn surface needs to be designed according to actual conditions; typically, this height ranges between 0.8 m and 1.2 m.

(4) The main supply duct can either run through trenches or above the ceiling. The branch supply ducts for small environments must be placed directly above the looms, with openings drilled directly into the air outlets to connect to the supply vents. Sliding air outlets are accessories that are independent of the supply vents.

(5) The regulating valves used in air outlets can be either manually or automatically controlled, depending on the customer’s preference. If automatic control is selected, when the loom stops operating, the air outlet for that loom will also close automatically. Once the air outlet is closed, the air pressure within the duct will increase, and accordingly, the blower will automatically reduce its air delivery rate.

(6) The air outlet can be directly installed on the duct. For small-space supply ducts, installation can be either suspended or supported on the ground.

(7) If the duct material is lightweight, the air outlet needs to be suspended separately.

(8) This system is typically used in conjunction with a mobile blow-suction fan, and the design must take into account how the supply air duct and the support structure for the blow-suction fan can be shared.

(9) The dimensions of the sliding air outlet and the opening dimensions at the duct connection depend on the dimensions of the supply air outlet.

  

Advantages:

(1) Direct air supply through the warp yarn surface—its advantages have already been explained in the preceding text.

(2) Suppresses flying debris and ensures high workshop cleanliness;

(3) Improve the efficiency of loom operation

(4) If the loom does not stop, the annual air supply remains essentially constant, making adjustment and management straightforward.

(5) Low air volume, low water spray rate, energy-saving, and low equipment investment.

(6) By reducing the diffusion of heat dissipation from the machinery, the machine’s heat is returned directly to the air-conditioning room via underground ducts before it has had sufficient time to fully mix with the workshop air—meaning that the cooling load (the cooling load requiring air treatment) is reduced.

(7) The air outlet has low resistance.

(8) Suitable for use with mobile blowers and vacuum cleaners.

   

Disadvantages:

(1) Compared to conventional central air conditioning systems, additional costs are required for air vents and installation.

(2) Typically, supply air ducts are installed beneath the ceiling, creating a visually oppressive atmosphere within the workshop.

(3) Dust tends to accumulate on the supply air ducts in the microenvironment.

(4) After the system has been running for a period of time, the sliding air dampers used to adjust airflow tend to get stuck and become difficult to slide.

 

Article-No.	Specification	Picture display
FKM1	W=222 L=1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000 2100, 2200, 2300, 2400, 2500
FKM2	W=302 L=1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000 2100, 2200, 2300, 2400, 2500
FKM3	W=402 L=1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000 2100, 2200, 2300, 2400, 2500

 

There are many types of return air outlets used in textile mills, including grille-type return air outlets, slotted return air outlets, funnel-shaped return air outlets for weaving workshops, and round-hole outlets, among others.

 

Article-No.	Specification	Picture display
Based on drawing	Floor grill Grid made of profile steel, hot-dip galvanized. Heavy-gauge steel construction. Mounting frame. Common size: 400x400 300x300
Based on drawing	Floor slots Heavy-gauge steel construction frame, hot-dip galvanized. Common size: 800x22 1000x22