消聲器，壓縮空氣自動排水器的原理及種類。

1.消聲器的功能。

1. Function of muffler.

氣動系統(tǒng)中，壓縮空氣經(jīng)換向閥向氣缸等執(zhí)行元件供氣，動作完成后，又經(jīng)換向閥排氣，由于閥的氣路復雜且十分狹窄，壓縮空氣以接近聲速的流速從排氣口排出，空氣急劇膨脹和壓力變化產(chǎn)生高頻噪聲。

In the pneumatic system, the compressed air is supplied to the cylinder and other executive elements through the directional valve. After the action is completed, the compressed air is discharged through the directional valve. Because the gas path of the valve is complex and very narrow, the compressed air is discharged from the exhaust port at a speed close to the sound speed. The air expands rapidly and the pressure changes produce high-frequency noise.

排氣噪聲與壓力、流量和有效面積有關(guān)，當閥的排氣壓力為0. 5 MPa時可達100dB以上，而且執(zhí)行元件速度越高，流量越大，噪聲也就越大，此時，必須用消聲器來降低噪聲。消聲器通過對氣流的阻尼或增加排氣面積等方法，來降低排氣速度和排氣功率，從而達到降低噪聲的目的。

The exhaust noise is related to the pressure, flow rate and effective area. When the exhaust pressure of the valve is 0.5 MPa, it can reach more than 100 dB. Moreover, the higher the speed of the actuator, the greater the flow rate, and the greater the noise. At this time, the muffler must be used to reduce the noise. The muffler can reduce the exhaust speed and power by damping the airflow or increasing the exhaust area, so as to reduce the noise.

2. 消聲器的分類。

2. Classification of muffler.

根據(jù)消聲原理不同，有吸收型、膨脹干涉型和膨脹干涉吸收型3類。

According to the principle of noise elimination, there are three types: absorption type, expansion interference type and expansion interference absorption type.

(1)吸收型消聲器它是利用吸聲材料消聲的。吸收型消聲器具有良好的中、高頻消聲性能，尤其是高頻噪聲，消聲效果大于15 dB。適合氣動系統(tǒng)使用。

(1) Absorption type muffler is made of sound absorption material. The absorption type muffler has good performance of middle and high frequency noise elimination, especially high frequency noise, and the noise elimination effect is more than 15 dB. Suitable for pneumatic system.

(2)膨脹千涉型消聲器它的工作原理是使氣體膨脹相互干涉而消聲。主要用于中：低頻，尤其是低頻噪南。

(2) Its working principle is to make gas expansion interfere with each other to eliminate noise. It is mainly used to eliminate medium and low frequency noise, especially low frequency noise.

(3)膨脹千涉吸收型消聲器這種消聲器的消聲效果好，低頻可消聲20dB,高頻可消聲45dB。

(3) This kind of muffler has good noise elimination effect. It can eliminate 20dB at low frequency and 45dB at high frequency.

選用消聲器時，應(yīng)合理選擇通過消聲器的氣流速度。對于一般系統(tǒng)可采取6~10m/s，對于高壓排空消聲器則可設(shè)定20m/s的氣流速度。

When choosing the muffler, the airflow velocity through the muffler should be selected reasonably. 6 ~ 10m / s for general system and 20m / s for high pressure exhaust muffler.

3.壓縮空氣自動排水器。

3. Compressed air automatic drainer.

隨著對空氣凈化要求的提高，利用人工的方法定期排污已不可靠，在一些場合不便于人工操作。因此自動排水器得到廣泛應(yīng)用。

With the improvement of air purification requirements, it is not reliable to use manual method to discharge sewage regularly, and it is not convenient for manual operation in some occasions. Therefore, automatic drainer is widely used.

自動排水器用于排出管道、油水分離器、儲氣罐及分水過濾器中的積水。自動排水器必須垂直安裝。在使用過程中，若自動排水器出現(xiàn)故障，可用手動操縱桿打開閥門放水。

The automatic drainer is used to drain the accumulated water in the pipeline, oil-water separator, gas storage tank and water separation filter. Automatic drainer must be installed vertically. In the process of use, if the automatic drainer fails, the manual control lever can be used to open the valve to drain water.