Dual back suction type range hood

Abstract

A dual back suction type range hood includes a wind collecting case. An upper half part and a lower half part of a front surface of the wind collecting case have at least one horizontally extending elongated first air-extracting port and at least one horizontally extending elongated second air-extracting port, respectively. The first air-extracting port is parallel to the second air-extracting port, and the two are in communication with at least one air-extracting device. When the air-extracting device draws air, the total air flow passing through the second air-extracting port is greater than the total air flow passing through the first air-extracting port at a same time. As such, after the second air-extracting port draws most of airborne grease and fumes, the first air-extracting port extracts a very small amount of airborne grease and fumes flowing upwards, thus achieving complete fume exhaustion.

What is claimed is: 
     
         1 . A dual back suction type range hood, comprising a wind collecting case, the wind collecting case connected to at least one air-extracting device, the wind collecting device having a front surface and a back surface opposite the front surface, an upper half part of the front surface of the wind collecting case having at least one horizontally extending elongated first air-extracting port, a lower half part of the front surface of the wind collecting case having at least one horizontally extending elongated second air-extracting port, the at least one first air-extracting port being parallel to the at least one second air-extracting port, the at least one first air-extracting port and the at least one second air-extracting port being in communication with the at least one air-extracting device; wherein, when the at least one air-extracting device draws air, a total air flow passing through the at least one second air-extracting port is greater than a total air flow passing through the at least one first air-extracting port at a same time. 
     
     
         2 . The dual back suction type range hood according to  claim 1 , wherein a total through hole area of the at least one second air-extracting port is greater than a total through hole area of the at least one first air-extracting port. 
     
     
         3 . The dual back suction type range hood according to  claim 2 , wherein the first air-extracting port is a circular hole, and the plurality of first air-extracting ports are horizontally elongated and arranged at an interval. 
     
     
         4 . The dual back suction type range hood according to  claim 1 , wherein the wind collecting case comprises a horizontal upper portion and a vertical portion that are configured as an inverted L-shaped, and the at least one first air-extracting port and the at least one second air-extracting port are formed on a front surface of the vertical portion. 
     
     
         5 . The dual back suction type range hood according to  claim 4 , wherein the wind collecting case has therein an accommodating space, the accommodating space is in communication with the air-extracting device, the at least one first air-extracting port and the at least one second air-extracting port, and the air-extracting device is connected on top of the wind collecting case. 
     
     
         6 . The dual back suction type range hood according to  claim 4 , further comprising a left vertical plate and a right vertical plate, the left vertical plate is joined at a lower part of a left side surface of the horizontal upper portion and extends downwards from the lower part of left side surface, and the right vertical plate is joined at a lower part of right side surface of the horizontal upper portion and extends downwards from the lower part of the right side surface. 
     
     
         7 . The dual back suction type range hood according to  claim 4 , wherein a lower surface of the horizontal upper portion of the wind collecting case further has a least one blowing opening, and the at least one blowing opening is located in the front of the front surface of the vertical portion and is parallel to the at least one first air-extracting port and the at least one second air-extracting port. 
     
     
         8 . The dual back suction type range hood according to  claim 1 , further comprising a second cover plate, and the second cover plate is movably positioned in a vertically movable manner on a front surface of the at least one second air-extracting port. 
     
     
         9 . The dual back suction type range hood according to  claim 8 , further comprising a first cover plate, the first cover plate is movably positioned in a vertically movable manner on a front surface of the at least one first air-extracting port, a plane of the first cover plate has at least one extending elongated third air-extracting port, and the at least one third air-extracting port is in communication with the at least one first air-extracting port. 
     
     
         10 . The dual back suction type range hood according to  claim 9 , further comprising a connecting member, and upper and lower ends of the connecting member are respectively connected to the first cover plate and the second cover plate to simultaneously move the first upper plate and the second upper plate.