Clamping device for explosion panels

Abstract

 The invention is for a clamping device for holding an explosion panel on the safety opening of a holder in which there is a dust, gas or vapour, which explosion panel will in the event of an excess of pressure, for example as a result of an explosion in the holder, be thrown open or blown off so that the holder sustains little or no damage.
The explosion panel (10) is made of rigid material and is equipped with a retaining edge (8) on which the free end of clip strips (6) fastened at an angle to a frame provided around the safety opening (2) of the holder (1) engages, which clip strips press the explosion panel (10) onto the frame.

Description

[0001] The invention is for a clamping device for holding an ex­plosion panel on the safety opening of a holder in which there is a dust, gas or vapour, which explosion panel will in the event of an excess of pressure, for example as a result of an explosion in the holder, be thrown open or blown off so that the holder sustains little or no dama­ge.

[0002] Such devices are known in a variety of embodiments.

[0003] In a known embodiment use is made of a flexible panel which can be held on the holder by a variety of means. In the event of an explosion in the holder the panel bends and the perimeter of the panel comes free of said means so that the panel is blown off.

[0004] However, because the opening pressure is governed in part by the bending of the panel a new panel must be de­signed and tested for every specific opening pressure.

[0005] In another known embodiment the means of retaining the panel consists of a number of leaf springs located around the perimeter of the panel, one end of which is mounted on the panel and the other end of which fits into a slot of a perpendicular support or frame mounted on the holder. In the event of an explosion the panel is pressed upwards and each flexible spring slides out of the slot of its support, so that the panel is blown off and the safety opening of the holder is cleared.

[0006] A major disadvantage of this is that the springs do not permit a good seal between the panel and the perimeter of the opening to be achieved. In order to remedy this to some extent, it is necessary to give the panel a rela­tively complicated shape. Yet another disadvantage is that the springs do not retain their springiness and are sensitive to temperature changes, so that it is diffi­cult to determine previously the opening pressure and/or opening time.

[0007] In order to remedy these disadvantages the invention provides for a clamping device in which a frame is fasten­ed around the safety opening and in which the explosion panel is rigid and provided with a retaining edge on which the free end of the clip strips fastened at an an­gle to the frame engages, pressing the explosion panel onto the frame.

[0008] Apart from remedying aforesaid disadvantages, the clamp­ing device and explosion panel according to the invention has the advantage that it is simple in construction and relatively cheap to make and that the explosion panel is easy to install. Another advantage is that the clamping device can be very precisely set to react to a predeter­mined very low or very high opening pressure at which it comes loose and is blown away. The opening pressure of the explosion panel can therefore be accurately deter­mined and is measurable. Yet another advantage is that after a mild explosion the panel can be used again and only the clip strips have to be replaced. Finally the opening pressure at which the explosion panel must open can be accurately determined in advance by changing the number and characteristics of the clip strips with which the explosion panel is fixed in position.

[0009] By way of example, without anyway being exhaustive, a more detailed description of a selected embodiment of the clamping device and the explosion panel is given be­low. This description refers to the attached drawing, in which :

fig. 1 shows a front elevation of the clamping device and the explosion panel;

fig. 2 shows a plan view of the same;

fig. 3 shows a longitudinal section along line III-III in fig. 2;

fig. 4 shows an enlarged cross-section along line IV-IV of fig. 2, in which the explosion panel closes off the safety opening of the holder;

fig. 5 shows the same cross-section as in fig. 4, but when the explosion panel is being blown free during an explosion.

[0010] In these figures will be seen the holder 1 which contains any dust, gas or vapour whatsoever and in which a safety opening 2 has been provided. Around this opening a per­pendicular frame 3 is fastened by means of, for example, of bolts 4. On the outside of the frame there are several supporting pieces or U shaped brackets 5 at predetermined distances in which a clip strip 6 which slopes downwards and made of any material whatsoever, is fastened by means of a screw 7. The free end of each clip strip 6 engages in a retaining edge 8 preferably turned to the horizontal of the outwardly sloping sides 9 of a rigid and not hea­vily constructed explosion panel 10 of any material what­soever, such as for example stainless steel, so that the explosion panel is firmly and sufficiently pressed onto the elastic seal 11 which is mounted on the perpendicu­lar frame 3. The force necessary to make the explosion panel come free of the safety opening 2 is determined by the buckling resistance of the clip strips 6. This buckling resistance of each strip can be accurately cal­culated on the basis of the dimensions of the clip strip and the strength coefficient of the material from which the clip strips 6 are made. The special shape of the clip strips 6 means that they exercise a constant pres­sure on the explosion panel 10, so that when combined with the rigid construction of the explosion panel they ensure perfect closing of the safety opening 2 of holder 1. Of great interest is the use of the clamping device and the explosion panel according to the invention when the normal operating pressure exerted on the panel is relatively close to the opening pressure of the explosion panel, when premature or unanticipated opening of the panel is undesirable or when the panel is subject to strict operating conditions.

[0011] When an explosion takes place in the holder 1, the ex­plosion panel 10 is lifted and the stiff retaining edge 8 of the explosion panel pushes the free end of the clip strips 6 upwards (fig. 5), so that the explosion panel slides freely over the clip strips and is blown free of the safety opening 2 of the holder 1. After a mild ex­plosion the rigid panel is usually not damaged and it is enough to replace the clip strips 6 in order to restore the device to good working order.

[0012] It goes without saying that the shape, the number and dimensions of the parts described above may differ and that some of these parts may be replaced by others which have the same purpose.

Claims

1.- Clamping device for explosion panels (10) for closing off a safety opening (2) in a holder (1) filled with dust, gas or vapour, around which opening a frame (3) is fastened and means of clamping are provided between this frame and the explosion panel for holding the explosion panel on the frame, characterized by the fact that the explosion panel (10) is made of rigid material and is equipped with a retaining edge (8) on which the free end of clip strips (6) fastened at an angle to the frame (3) engages, pressing the explosion panel (10) onto the frame.

2.- Clamping device according to claim 1, characterized by the fact that a supporting piece (5) is mounted on the holder (1) opposite each clip strip (6) to support the side (9) of the explosion panel (10) lying against it.

3.- Clamping device according to claim 1, characterized by the fact that the explosion panel (10) is provided with at least one side which slopes outwards the free edge of which is turned horizontally inwards and forms the retaining edge (8).

4.- Clamping device according to claims 2 and 3, charac­terized by the fact that each supporting piece consists of a U shaped bracket (5), between which bracket and a frame (3) mounted on the holder (1) the back of the clip strip (6) is fastened the free end of which slopes down­wards into the U shaped bracket, between which bracket (5) and clip strip (6) the upturned retaining edge (8) of the explosion panel (10) is held.

Drawing