JPH0377616A - Preventing device for freezing water in air filter - Google Patents

Abstract

PURPOSE:To prevent the freezing of the water stored in an air filter by providing a heater for the air filter and arranging a temp. detector capable of controlling the current to be applied to the heater in accordance with its detection value at a position where the temp. changes of the external air and filter can be detected. CONSTITUTION:The heater H capable of heating an air filter F and the temp. detector T capable of controlling the current to be applied to the heater in accordance with its detection temp. are provided at the least, and the detecting element 8 of the detector is arranged at a position where the temp. change of the external air and that of the filter due to the heat of the heater can be detected. Accordingly, the filter is moderately heated by the heater in the coldest season to prevent the freezing of water in the filter. In addition, one temp. detector can be shared by use as the external air temp. sensor and the thermostat for preventing the overheating of the heater, and the reduction in cost is attained.

Description

Detailed Description of the Invention A9 Purpose of the Invention (1) Industrial Field of Application The present invention relates to an air compressor for filtering foreign matter such as moisture and dust from compressed air supplied to air-operated equipment such as an air cylinder. The present invention relates to a water freezing prevention device in a filter device.

(2) Prior art In the conventional air filter device mentioned above, moisture filtered from the air is temporarily stored inside the device, and then drained to the outside manually or automatically at an appropriate time. That's what I was doing.

(3) Problems to be Solved by the Invention The above-mentioned conventional devices have problems such as the water stored in the air filter device freezing in extremely cold weather and becoming unable to be discharged, or the air filter device itself being damaged. there were.

The present invention has been proposed in view of the above, and an object of the present invention is to provide a water freezing prevention device for an air filter device that can solve the above problems of conventional devices.

B0 Structure of the Invention (1) Means for Solving the Problems In order to distantly achieve the above object, the present invention provides a water filter device for filtering foreign substances such as moisture from air supplied to air-operated equipment. A freeze prevention device comprising at least a heater capable of heating an air filter device and a temperature detection device capable of controlling energization of the heater according to a detected temperature, the temperature detection section of the temperature detection device comprising: It is characterized in that it is disposed at a position where it can detect both a temperature change in the outside air and a temperature change in the air filter device due to heat generation from the heater.

(2) Effect According to the above configuration, the temperature detection device can appropriately control the energization to the heater according to the temperature change of the outside air or the temperature change of the air filter device due to heat generation of the heater. For example, when the outside air falls below a predetermined temperature, the heater is energized to heat the air filter device, and when the air filter device rises to a predetermined temperature or higher due to the heating, the energization to the heater can be stopped.

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings. An air filter device F supplies air from an air source S such as an air tank or a compressor to an air-operated device A such as an air cylinder through an air conduit 1. It is installed to remove foreign substances such as moisture and dust from compressed air.
A box-shaped filter case 2 which is interposed in the middle of the air conduit 1 and houses therein a filter material (not shown) capable of filtering moisture and dust from the air flowing through the air conduit 1; The filter case 2 includes a bottomed cylindrical water storage case 3 which is integrally connected to the lower part of the filter case 2 and can store water filtered by the filter medium therein.

A drain port 3a is provided at the bottom of the water storage case 3 for discharging the water inside the case 3, and a predetermined amount or more of water accumulates in the water storage case 3 above the drain port 3a. A known valve device (not shown) is provided to automatically open the valve and allow water to flow down from the drain port 3a. Furthermore, the outer periphery of the lower half of the water storage case 3 is surrounded by an electric heater H, and when heat is generated from this heater H, the heat is directly transmitted to the water storage case 3, and the water stored in the case 3 is frozen. can be prevented.

The lower part of the filter case 2, the water storage case 3, and the heater H are surrounded by a cylindrical heat-insulating case 4 whose bottom is made of heat-insulating material, and the upper end of the heat-insulating case 4 is
It is fixed to a support flange portion 2f fixed to the filter case 2 with screws b. Further, a water passage hole 4a is provided at the bottom of the heat retaining case 4 to allow water flowing down from the drain port 3a at the bottom of the water storage case 3 to fall.

One end of an abbreviated metal support bracket 5 extending laterally is fixed to the filter case 2 with a screw b2, and the other end of the bracket 5 extending in the vertical direction is fixed to the filter case 2. It is fixed to the wall surface 6 or other suitable supporting surface with screws b3.

A device main body 7 of a temperature detecting device T is fixed to the intermediate portion of the support bracket 5, and a temperature detecting portion 8 of the temperature detecting device T is integrally provided on the lower surface of the device main body 7. There is. Since the temperature detection section 8 is exposed to the outside air, it can detect changes in the outside temperature, and is also close to the middle part of the support bracket 5 connected to the filter case 2 and connected to the main body 7 of the device. Since they are in contact with each other through the support bracket 5, it is possible to detect a temperature change in the support bracket 5, and furthermore, a temperature change in the air filter device F due to the heat generation of the heater H. Further, the temperature detection device T can control the energization to the heater H according to the detected temperature.
and heater H are connected to power supply circuit 9 via cords 10 and 11.

The temperature detection device T starts energizing the heater H when the temperature detection unit 8 becomes lower than the first set temperature (for example, 3°C), and thereafter, the temperature detection unit 8 starts energizing the heater H. A second set temperature that is higher than the first set temperature (for example, 5°C)
It is configured to stop energizing the heater H when the temperature reaches a higher temperature.

Next, the operation of the above embodiment will be explained. Air filter device F
filters moisture, dust, etc. from the compressed air flowing through the air conduit 1, and especially moisture can be stored in the water storage case 3 until it reaches a predetermined amount.

In extremely cold weather, the outside temperature is close to freezing, for example 3°.
When the temperature falls below C, the temperature detection device T starts energizing the heater H. This heats the water storage case 3,
Freezing of the water stored therein is prevented.

Due to the heat generated by the heater H, the temperature of the air filter device F and therefore its support bracket 5 gradually rises. Then, when the temperature detection unit 8 rises in temperature due to the heat transmitted through the support bracket 5 and reaches 5°C or more, the temperature detection device T
stops the power supply to the heater H, thereby preventing the heater H from overheating. As the power supply to the heater H is stopped, the air filter device F gradually cools down and its temperature decreases, and when the temperature of the temperature detection section 8 finally reaches 3°C or less, the temperature detection device T turns off the power to the heater H again. The power supply is restarted, and the same operation is repeated thereafter.

C0 Effects of the Invention As described above, according to the present invention, the temperature detection device includes at least a heater capable of heating an air filter device and a temperature detection device capable of controlling energization of the heater according to a detected temperature. The temperature detection section is disposed at a position where it can detect both the temperature change of the outside air and the temperature change of the air filter device due to heat generation of the heater. The power supply to the heater can be appropriately controlled according to the temperature change of the air filter device due to heat generation. Therefore, in extremely cold weather, the air filter device can be appropriately heated by the heater, and the water inside the device can be heated appropriately. Freezing can be prevented. Moreover, since it can be used in common with a thermostat for preventing overheating, the structure is simpler and can contribute to cost reduction.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall perspective view thereof, and FIG. 2 is a sectional view taken along the line ■--■ in FIG. 1. F...Air filter device, H...Heater, T...
Temperature detection device, 8...temperature detection section

Claims (1)

[Claims] A water freezing prevention device in an air filter device for filtering foreign substances such as moisture from air supplied to air-operated equipment, comprising a heater (H) capable of heating the air filter device (F), and the heater The temperature detecting unit (8) of the temperature detecting device (T) detects temperature changes in the outside air and detects temperature changes in the outside air. A device for preventing water from freezing in an air filter device, characterized in that it is disposed at a position where it can detect temperature changes in the air filter device (F) due to heat generation of (H).