Apparatus allowing ventilation through a ventilation shaft to an underground ventilation duct fluidly communicating through the ventilation shaft to an atmospheric opening of the shaft and on threat of flooding operable to prevent downward flow of surface water into the underground ventilation duct includes support sidewalls fitting in the shaft providing a ventilation passage between support top and bottom openings and a suspension member supported on opposed lateral sidewalls unobstructively horizontally spanning the passage proximate the top opening and holding one or more hinge connected panels in the passage that manually release to rotationally close the passage and prevent flooding and are manually rotationally liftable to a home position allowing ventilation. The suspension member is liftingly removable from the support and may include end keys received in keyed supports to allow the suspension member to fit in the supports so a specific panel closes to a specific sidewall.

Apparatus allowing ventilation through a ventilation shaft to an underground ventilation duct fluidly communicating through the ventilation shaft to an atmospheric opening of the shaft and on threat of flooding operable to prevent downward flow of surface water into the underground ventilation duct includes support sidewalls fitting in the shaft providing a ventilation passage between support top and bottom openings and a suspension member supported on opposed lateral sidewalls unobstructively horizontally spanning the passage proximate the top opening and holding one or more hinge connected panels in the passage that manually release to rotationally close the passage and prevent flooding and are manually rotationally liftable to a home position allowing ventilation. The suspension member is liftingly removable from the support and may include end keys received in keyed supports to allow the suspension member to fit in the supports so a specific panel closes to a specific sidewall.

An assembly that fits within a ventilation shaft open to atmosphere and leading from underground ventilation ducts such as to subways prevents surface waters from flooding the underground ducts while maintaining the ventilation. The assembly fits in the ventilation shaft and houses a buoyant float in a chamber surrounding a passageway in fluid communication with the ventilation shaft. A grate covers the passageway. An outside wall of the chamber adjacent the ventilation shaft is open at top to atmosphere and allows flooding water into the chamber, buoying the float upward in the chamber, elevating the passageway above the flooding water. The chamber suitably has means for drainage and admission of flush water to flush flood water debris from the chamber through the drainage.

An assembly that fits within a ventilation shaft open to atmosphere and leading from underground ventilation ducts such as to subways prevents surface waters from flooding the underground ducts while maintaining the ventilation. The assembly fits in the ventilation shaft and houses a buoyant float in a chamber surrounding a passageway in fluid communication with the ventilation shaft. A grate covers the passageway. An outside wall of the chamber adjacent the ventilation shaft is open at top to atmosphere and allows flooding water into the chamber, buoying the float upward in the chamber, elevating the passageway above the flooding water. The chamber suitably has means for drainage and admission of flush water to flush flood water debris from the chamber through the drainage.

A dry filter 1 to be used in particular in underground mining and tunnel construction having a frame construction 17 into which the required part housings 25-28 can be inserted from the side. The required partition wall 8 is arranged so that an optimal large filtering surface is available both for the incoming raw gas and for the outflowing clean gas. Raw gas duct 5 and clean gas duct 6 run horizontally one above the other and are separated from each other by the sloping 8. This means that a very large filtering surface is available.

A dry filter 1 to be used in particular in underground mining and tunnel construction having a frame construction 17 into which the required part housings 25-28 can be inserted from the side. The required partition wall 8 is arranged so that an optimal large filtering surface is available both for the incoming raw gas and for the outflowing clean gas. Raw gas duct 5 and clean gas duct 6 run horizontally one above the other and are separated from each other by the sloping 8. This means that a very large filtering surface is available.

In an aspect, there is disclosed a system for providing ventilation to a ventilated location within a passageway. The system includes: a duct arranged to extend between an inlet location to an outlet location proximate the ventilated location; an axial fan fitted with the duct having an impellor adapted move air between the inlet location and the outlet location a controllable vane located within the duct relatively upstream of the impellor; a sensor located relatively downstream of the impellor adapted to provide a measurement indicative of a volumetric flow rate discharged from the outlet location; and a controller in operative communication with the sensor and the vane, the controller being configurable to determine the volumetric flow rate and control the vane so as to maintain the volumetric flow rate above a pre-determined minimum volumetric flow rate. Other examples of the system and associated methods are also disclosed.

In an aspect, there is disclosed a system for providing ventilation to a ventilated location within a passageway. The system includes: a duct arranged to extend between an inlet location to an outlet location proximate the ventilated location; an axial fan fitted with the duct having an impellor adapted move air between the inlet location and the outlet location a controllable vane located within the duct relatively upstream of the impellor; a sensor located relatively downstream of the impellor adapted to provide a measurement indicative of a volumetric flow rate discharged from the outlet location; and a controller in operative communication with the sensor and the vane, the controller being configurable to determine the volumetric flow rate and control the vane so as to maintain the volumetric flow rate above a pre-determined minimum volumetric flow rate. Other examples of the system and associated methods are also disclosed.

A ventilation system for a subway platform includes: an air supply duct through which air supplied to the interior of a subway platform flows; an exhaust duct through which air supplied to the outside of the subway platform flows; a plurality of air supply hoods that supply air in the air supply duct to the interior of the subway platform and are arranged to be apart from each other in a direction in which air flows through the air supply duct; and a plurality of exhaust hoods that exhaust air from the subway platform together with pollutants in the subway platform to the exhaust duct and are arranged to be apart from each other in a direction in which air flows through the exhaust duct, wherein the air supply hood is arranged to be inclined downward at an angle toward one side of the subway platform to supply air.

Provided is a blower installed at a manhole opening, with which it is possible to facilitate an entry or an exit of a worker or an import or an export of an article. The present invention provides a ventilation system comprising a frame and a single or a plurality of airflow generation means arranged at the frame, a direction of an airflow is adjusted so that the airflow generated from the airflow generation means flows along with a virtual axis penetrating a virtual surface which the frame is regarded as to periphery, and the airflow flows while swallowing up the surrounding air of the virtual axis, and an air volume more than two times of total fluid volume of the airflow is generated.