Self-priming filter respiratory protection products limitations
1. The external shape of the self-absorbing filter-type respiratory protective product mask occupies the visual field of the wearer, which narrows the visual field of the wearer and directly affects the wearer's operation. 2. After wearing self-priming filter-type respiratory protective equipment, the ventilation of the human body is limited, and the maximum oxygen consumption is reduced, which affects the extreme sports ability of the wearer. Especially in a sports or thermal environment, the heat discomfort caused by the self-absorbing filter-type respiratory protective article will increase the load of the human body and also reduce the human body's ability to operate. The maximum output power is 18%~34% when no respiratory protective equipment is worn. 3. Increased concentrations of carbon dioxide in the inhaled gas will also affect the wearer’s operations. High concentrations of the dioxin center may cause discomfort and anxiety. Anxiety can affect the operation; carbon dioxide also has an effect of local vasodilation, and other exercise muscles have reduced blood supply due to shunting. Reduced athletic ability. 4, due to lack of oxygen, brain and other important organs and sensory organs function is affected, so as to affect perception, exercise coordination and memory, understanding, judgment, thinking and other intelligence. Oxygen concentration 16% (under standard state STP) will lead to faster heart rate and respiratory rate, increased breathing, affecting attention and operation ability; abnormal oxygenation, emotions below 14% (under standard state STP) Decline and loss of judgment; Oxygen concentration dropped to 10% (under standard STP), nausea, vomiting, loss of consciousness, inability to perform operations, and even death. Tip: Self-priming filter respiratory protection products are only suitable for environments where the air concentration is not lower than 19.5%. Once the air concentration is lower than the specified value, they should be immediately replaced with isolated respiratory protection products or immediately evacuated to a safe area. In order to improve the operating ability of the wearer of the self-absorbing filter-type respiratory protective article, it is necessary to reduce the influence of the respiratory protective article on the wearer's visual field from the aspect size. And by reducing respiratory resistance, reducing dead space, etc., to reduce self-absorption filter respiratory protection products on the body's respiratory system, cardiovascular system, body temperature regulation system and so on. This article is a reprint of online media. It only represents the author's point of view. It has nothing to do with this site. If news articles and comments infringe your legal rights, please call us and we will handle it in a timely manner.
small fan
DC Fan is through the input DC power, so that the DC motor rotates to drive the fan impeller rotation, in order to achieve DC to mechanical energy conversion process fan. The biggest feature of Dc Fan is the optional DC motor.
Introduction
At present, DC fans use more DC brushless motors. Brushless DC motors eliminate the need for slip rings and brushes for excitation and greatly simplify the structure. At the same time, it not only improves the processability of the motor, but also greatly enhances the mechanical reliability of the motor operation and increases the service life.
At the same time air gap flux density can be greatly improved, the motor indicator can achieve the best design, the direct effect of the motor is reduced in size and weight. Not only that, but also has very good control performance compared to other motors. This is because: First, the torque constant, moment of inertia ratio, power density and the like of the motor are greatly increased due to the high performance of permanent magnetic materials. Through rational design and can make the moment of inertia, electrical and mechanical time constants and other indicators greatly reduced, as a major indicator of servo control performance has been greatly improved. Second, the design of modern permanent magnetic circuit has been more perfect, coupled with the high coercivity of permanent magnetic materials, and thus permanent magnet motor anti-armature reaction and its anti-demagnetization greatly enhanced the control parameters of the motor with the external Disturbance effect greatly reduced. Thirdly, since the permanent magnet replaces the electrical excitation and the design of the field winding and the field magnetic field is reduced, the parameters of the field flux, the field winding inductance and the field current are reduced, thereby directly reducing the controllable variable or the parameter. Based on the above factors can be said that permanent magnet motor with excellent controllability.
At present, large-capacity fan air flow control has been a lot of frequency control methods, this type of inverter mainly rely on imports, expensive. Currently 1kw below the power level of fans, especially home air conditioners and other fans have permanent magnet brushless DC motor drive, and the use of speed control air volume method. 1 ~ 10kw power range of the huge amount of fan, the basic induction motor drive, and adjust the outlet opening to adjust the amount of wind. For fans in this power range, using permanent magnet brushless DC motor drives to replace the original induction motor drive has great advantages.
DC Fan Dc Fan,Dc Cooling Fan,Plastic Dc Fan Shenzhen Fusheng Motor Co.,Ltd , http://www.fushengfan.com
