referring to fig2 , an exploded perspective view of a compact horizontal air purifier according to a preferred embodiment of the present invention is illustrated , in which the compact horizontal air purifier comprises an outer case 1 having a center opening 111 and a plurality of parallelly and spacedly apart holes 112 at two sides of the outer case 1 to define a inlet port 112 a and a outlet port 112 b for an air flowing from one side of the outer case 1 to another opposed side thereof ; a frame 2 which can be slidably inserted and pulled out from the center opening 111 ; a first array electrode 3 mounted on frame 2 ; a second array electrode 4 apart from the first array electrode 3 ; and a high - voltage pulse generator 5 having a positive electrode 51 and a negative electrode 52 electrically and selectively connected with the first array electrode 3 and the second array electrode 4 respectively as the frame 2 is inserted into the predetermined position of the outer case 1 . referring to fig3 , a sectional view of fig2 , the first array electrode 3 comprises a plurality of parallelly and spacedly apart plate - shaped small annular electrodes 31 . the second array electrode 4 comprises a plurality of parallelly and spacedly apart plate - shaped large annular electrodes 41 which are larger than the small annular electrodes 31 . accordingly , the small and large annular electrodes 31 , 41 are the metal made hollow collecting dust vane . the frame 2 has a top plate 21 and a bottom plate 22 , wherein one end of each of the large annular electrodes 41 and one end of each of the small annular electrodes 31 are mounted at the top plate 21 and an opposed end of each of the large annular electrodes 41 and an opposed end of each of the small annular electrodes 31 are mounted at the bottom plate 22 . each of the large annular electrodes 41 must be in hollow shape , wherein each of the small annular electrodes 31 can be in hollow shape or solid structure . the large annular electrodes 41 can be embodied as a hollow square body 411 a , hollow triangular body 411 b , or hollow polygonal body 411 c , as shown in fig4 . the first array electrode 3 mounted on the frame 2 comprises a plurality of parallelly and spacedly apart plate - shaped small annular electrodes 31 , wherein one end of each of the small annular electrodes 31 is mounted on the top plate 21 , and an opposed end of each of the small annular electrodes 31 is mounted on the bottom plate 22 . the small annular electrode 31 is mounted at the air inlet . the margin between each of the small annular electrodes 31 a and the corresponding large annular electrode 41 a is the same , wherein the small annular electrodes 31 are aligned with the large annular electrodes 41 a to avoid arc discharge , which will result in dramatically leap of ozone , making user uncomfortable . each of the small annular electrodes 31 a can be in hollow shape or in solid structure . in the preferred embodiment , the number of the small annular electrodes 31 equals to the number of the large annular electrodes 41 to align with each other , but the number of the small annular electrodes 31 and large annular electrodes 41 may vary and the position of them may be not perfectly aligned with each other , which may not affect the performance of the air purifier . each small annular electrode 31 is electrically connected with a small annular electrode connector 221 on the bottom plate 22 , and each large annular electrode 41 is electrically connected with a large annular electrode connector 222 on the bottom plate 22 . accordingly , the small and large annular electrode connectors 221 , 222 are individual connectors spacedly formed at the bottom plate 22 . alternatively , the small and large annular electrode connectors 221 , 222 are two common connectors spacedly formed at the bottom plate 22 . the top plate 21 further comprises a handle bar 211 mounted thereon for inserting into and pulling out the frame 2 by the hand of the user . both the large annular electrodes 41 and small annular electrodes 31 are plate - shaped conductor made of well - conducted materials with certain rigidity and hardness , such as stainless steel , nickel , carbon and so on . the outer case 1 comprises a base 11 defining a plurality of small annular electrode contacts 221 for electrically coupling with the small annular electrode connectors 12 respectively and a plurality of large annular electrode contacts 222 for electrically coupling with the large annular electrode connectors 13 respectively when the frame 2 is slidably inserted into the outer case 1 . the number of the small annular electrode contacts 221 equals to the number of the small annular electrode connectors 12 . the number of the large annular electrode contacts 222 equals to the number of the large annular electrode connectors 13 . the small annular electrode connector 12 and the large annular electrode connector 13 on the base 11 are electrically connected with the positive electrode and negative electrode of the high - voltage pulse generator 5 respectively . as the frame 2 is inserted into the predetermined position of the outer case 1 , each small annular electrode contact 221 and large annular electrode contact 222 on the base 11 are electrically connected with the small annular electrode connector 12 and large annular electrode connector 13 to electrically connect with the small and large annular electrodes respectively . the operation of the present invention is described explicitly hereinafter . for operating the air purifier , the frame 2 is slidably inserted into the predetermined position of the outer case 1 . the small annular electrode connectors 221 and large annular electrode connectors 222 at the bottom plate 22 are electrically connected with the small annular electrode connectors 12 and large annular electrode connectors 13 at the base 11 respectively . the high - voltage pulse generator 5 outputs a series of high voltage pulse from 4 kv to 25 kv . the air between the first array electrode 3 and the second array electrode 4 is ionized to produce air flow and certain mount of ozone from the first array electrode 3 to the second array electrode 4 . most particles in the air flow are attracted by the electro static force on the small annular electrodes 31 and large annular electrodes 41 to purify the air . certain amount of ozone can sterilize and disinfect the air . when the air purifier needs to be cleaned , the frame 2 is slidably pulled out with the first array electrode 3 and the second array electrode 4 mounted thereon , and the user can insert them back to the outer case 1 after cleaning . in the present invention , the position of each small annular electrode 31 and large annular electrode 41 of the first and second array electrodes 3 and 4 of the compact horizontal air purifier can be alignedly face to face , or may have a little deviation , so that the degree of accuracy during manufacturing is reduced , and the production efficiency is thus increased . furthermore , the small array electrodes 31 are high - strength plate - shaped instead of string - shaped , so that it can be easily cleaned and not easy to break . in addition , the first and second array electrodes 3 and 4 are mounted on the frame 2 that can be detachably pulled out from the outer case 1 of the air purifier to be cleaned and inserted back for use again , so that the small annular electrode 31 is easy to be cleaned , which improves the operation efficiency of the air purifier . finally , when the frame 2 is inserted into the predetermined position of the outer case 1 , the connectors 21 and 22 on the frame 2 are electrically connected with the contacts 12 and 13 on the base 11 of the outer case 1 respectively , so that the first and second array electrodes 3 , 4 can get electrical power from the high - voltage pulse generator 5 , which is very convenient . the present invention provides a compact horizontal air purifier with the following installation requirements . the small annular electrode 31 must be smaller than its corresponding large annular electrode 41 wherein the smaller annular electrode 31 must be mounted at the air inlet . the margin of the small annular electrode 31 and its corresponding large annular electrode 41 must be equal and alignedly face to face to avoid arc discharge , which will result in dramatically leap of ozone , making people uncomfortable . the small annular electrode 31 can be formed in hollow shape or solid structure and its corresponding large annular electrode 41 must be in hollow shape . the small annular electrode 31 and large annular electrode 41 are electrically connected with the two electrodes of high - voltage pulse generator 5 respectively . if the large annular electrode 41 is connected with positive electrode and the small annular electrode 31 is connected with negative electrode , the release volume of the ozone is fewer . if the small annular electrode 31 is connected with positive electrode , and the large annular electrode 41 is connected with negative electrode , the release volume of the ozone is higher . at least one group of small annular electrode 31 and large annular electrode 41 are needed , and the small one discharges facing to the large one to produce electromotive force forming breeze . one or more groups of small annular electrode 31 and large annular electrode 41 are required to form an installation structure . one skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting . it will thus be seen that the objects of the present invention have been fully and effectively accomplished . the embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles . therefore , this invention includes all modifications encompassed within the spirit and scope of the following claims .