The specifications of SDS series jet fans are from 630mm to 1600mm. They are divided into two categories: unidirectional running axial fans and reversible (bidirectional) running axial fans. The maximum thrust is 3500N. For any load
Efficient and low-noise fans can be selected under all conditions.
SDS series jet fan adopts advanced technology to obtain good quality assurance. The fan casing is formed by special flanging machine imported from the United States. The inner wall of the impeller section is processed by gold
, Not only to ensure the coaxiality and strength of the casing, but also to ensure the radial clearance of the blade, the surface is hot-dip galvanized or other equivalent coating treatment, beautiful appearance and corrosion resistance, excellent performance, fan blades
The wheels are processed into a die-casting mold cavity by a fully automatic CNC boring and milling machining center of Toshiba Corporation of Japan. The aluminum alloy high (low) die-casting is performed on a high-pressure casting and a low-pressure casting machine, respectively.
The actual use of road tunnels, railway tunnels, water conservancy dam projects and other users has proved that the performance indicators of the fan and the technical, quality requirements and economical requirements such as corrosion resistance, reliability, and economy.
Economic indicators can fully adapt to the use of various types of tunnels and subways.
Product usage description
In the construction of subways, highway tunnels, railway tunnels and other basic projects, the air quality standards and safety factors rely on the forced ventilation of fans to meet the requirements. In the case of ventilation systems,
Maintain good air quality, otherwise it is harmful to human body, as shown in the figure.
Tunnel ventilation system design and product selection basis
In principle, traffic tunnels can be divided into three categories: subways, highway tunnels, and railway tunnels.
The prerequisite for the safety and reliability of normal operation and emergency operation is the installation of an environmental control system that ensures coordination between the various systems and fully functions.
A Mechanical system: ventilation, firefighting ', sewage B Power system: power supply, transmission and distribution, emergency power
C Lighting system: On-light, local lighting, fluorescent indicator D Communication system: telephone, radio, computer terminal
E Transportation system: lights, signals, signs, surveillance F Control system: monitoring of traffic and equipment conditions and equipment operating conditions
The tunnel ventilation system can have the following three basic methods or a hybrid method.
1 Longitudinal ventilation system: This is the most basic ventilation method. The fresh air flows from the entrance end to the exit end of the tunnel, and there is no need to install ventilation ducts along the longitudinal direction of the tunnel. This ventilation method is generally used
Reversible jet fan. The fan is installed on the top or side of the tunnel, and can be fully ventilated in two directions to achieve two-way ventilation or control smoke; if the tunnel is longer, a central
Supply and exhaust shafts are connected to the atmosphere to form a mixed ventilation mode.
2 Full lateral ventilation system: Set up the supply and exhaust ducts along the tunnel direction. Fresh air is collected from the wind pavilion and exhausted from the wind tower. Generally, the supply duct is set below the road surface to exhaust air.
The road is set in the upper part of the driveway, and the air supply and exhaust air ducts are provided with air supply and exhaust vents at regular intervals. In an accident condition, the air is exhausted along the cross section of the tunnel in time to extract smoke.
3 Semi-transverse ventilation system: This system can be divided into supply-type semi-transverse ventilation mode and exhaust-type semi-transverse ventilation mode. Generally, exhaust-type semi-transverse ventilation mode is adopted, and fresh air flows from the tunnel.
At the entrance, the exhaust air is similar to a full lateral ventilation system.
4 Factors to be considered in the tunnel ventilation system:
A Project investment B Electric capacity C Operating cost D Air quality E Safety factor F Guarantee measures in emergency
Establish the optimal plan after the above factors are economically integrated
5. Factors in the number and number of fans in the tunnel ventilation system:
A CO, NOx and smoke concentration B Vehicle flow (vehicle density, speed)
C Wind load (tunnel length * width * height) D Exhaust emissions (age, quantity)
E Emergency measures in case of fire
6. Theoretical basis for thrust calculation of tunnel ventilation system
1 Basis of thrust calculation of tunnel ventilation system
Inlet and outlet resistance loss? Friction coefficient of tunnel surface and equipment
Coefficient of Vehicle Friction (Calculation of Vehicle Motion or Piston Wind Effect in the Worst Case)
Impact of wind speed outside the tunnel on entrances and exits under the worst conditions? Tunnel topography, location (slope, altitude)
Thrust (temperature, pressure, time) required in case of fire
2 The tunnel pressure reduction (Pa) theory is converted into the thrust required by the jet fan (N)
The thrust of the jet fan is the momentum change of the fan inlet and outlet, that is, the fan thrust
N = C * mass flow * air velocity (N)
In the formula: N = static thrust of the fan (LSO) N value C = empirical correction factor
Mass flow = air density * volume flow
The relative speed between the jet fan used in the tunnel and the airflow in the tunnel, the friction coefficient in the tunnel, and the parallel arrangement of the same group are related. Therefore, the effective thrust of the jet fan is:
N = N * (1-V / V) C * C
In the formula: N = effective thrust of the fan (N) V = wind speed in the tunnel (m / s)
V = jet velocity (m / s) C = friction coefficient in the tunnel
C = Loss of flow direction arranged in parallel in the same group (this loss can be ignored if the fan diameter is 100 times the diameter of the fan, so that the jet speed does not affect the operating conditions in the direction of the air stream).
7. Structural features of the fan used in the tunnel ventilation system
The tunnel fan is divided into unidirectional jet fan (SDS) and bidirectional jet fan [SDS (R)].
Fan body, muffler, bracket feet: CNC automatic welding and mechanical molding of steel plate, surface coating treatment to ensure fan strength and anti-corrosion
Fan impeller: To meet the needs of tunnel ventilation, SDS series fans can change the number of blades and the angle of the fan blades
Muffler: The length of the muffler is usually twice the diameter of the fan. When the noise requirements are high, the diameter of the fan can also be doubled. The muffler and the fan body are fixed by bolts.
Supporting motor: SDS series jet ventilator supporting motor is squirrel cage fully enclosed, the motor is equipped with flange mounting disks, the motor insulation level is H level, the corrosion resistance level is IP55, the motor
The lead-out cable can be connected to the junction box on the fan body casing. The motor has a grease nipple, and an external metal hose is connected to the grease nozzle on the fan body casing.
Fan reversible switching time: In an emergency state, the jet fan's forward and reverse switching time is extremely important. The SDS (R) type fan has two types of electronic and mechanical switching methods, which can be performed in 30 seconds.
The internal positive and negative switching to the fan rated speed.
SDS series jet fan test test
Thrust test: Measured with a thrust test device.
High temperature fire test: Tested by Tianjin Fire Test and Inspection Center of the Ministry of Public Security.
Noise test: The silencer with and without the silencer is tested on an open field (when the atmospheric wind speed is close to 0). The sound pressure level of the fan is tested along the axis of the fan.
Measured at an angle of 45m from the fan at 10m.
Fan efficiency: Fan operating efficiency is defined by measuring thrust (N) and motor input power (KW).
The test and inspection are carried out by Shangjian Company's Engineering Technology Center (Experimental Research Center) in strict accordance with relevant national and industry standards, and tested by provincial and national authoritative supervision institutions.