A new type of high-efficiency automobile air dryer

Abstract

The present invention proposes a novel high-efficiency automobile air dryer, comprising a shell with a closed upper end, a bottom cover, and a filter element. The bottom cover is provided with an air inlet and a threaded bayonet for connecting an external air pipeline; an inner liner is provided in the shell, an inner liner cover and a connecting plate are provided on the inner liner, and a downwardly extending portion in the middle of the bottom of the connecting plate is sleeved outside the threaded bayonet of the bottom cover, the inner cavity of the inner liner constitutes a desiccant storage cavity, a spring is provided between the inner liner cover and the shell, a channel communicating with the inner liner is provided on the inner liner cover, and the cavity between the inner liner and the shell constitutes an air channel, the filter element is provided on the upper part of the inner liner and communicates with the inner cavity of the inner liner, and a one-way bypass valve and an elastic one-way check valve plate are also provided on the channel of the inner liner cover; a fixing rod is provided in the central vertical direction of the desiccant storage cavity, and a spiral plate is fixed on the fixing rod, and the outer contour of the spiral plate is adapted to the inner wall of the inner liner. The present invention can filter oil stains in compressed air, completely remove moisture, ensure automobile braking performance, and improve safety.

Description

Technical Field

[0001] The invention relates to the technical field of air dryers, and in particular to a novel high-efficiency automobile air dryer. Background Art

[0002] The car air dryer is an indispensable part of the car, especially some heavy-duty cars. Its function is to dry the compressed air from the car's air pump so that the moisture contained in the gas will not enter the car's braking system through the gas, thereby keeping the car's braking system sensitive and effective.

[0003] Due to the serious oil leakage phenomenon of domestic air pumps, the air coming out of the air pump contains not only moisture, but also oil and solid impurities. The desiccant in the ordinary automobile air dryer can only absorb the moisture in the compressed air, but cannot filter the oil mist in the compressed air in advance. At the same time, the drying material in the air desiccant will lose its function of drying moisture after contacting with oil, which will quickly cause the dryer to fail, and then affect the braking performance of the car, posing a serious safety hazard; at the same time, due to the short service life of the desiccant, the maintenance cost is increased.

[0004] Patent application number 201820380584.3, "An Oil Filter Dryer Cylinder for Air Dryer", discloses a device that can prevent moisture and particulate matter contained in compressed air from entering the piping system behind the dryer. The device allows the compressed air to first pass through a filter element to filter the oil, and then pass through a molecular sieve to absorb the moisture.

[0005] The inventors found in the process of implementing the present invention that:

[0006] The technical solution of "An Oil Filter Dryer Cylinder for Air Dryer" with patent application number 201820380584.3 is being implemented. Since the three-dimensional installation space of the dryer reserved during the design of the whole vehicle is fixed, that is, the air dryer is limited by the installation space and the height cannot be designed to be too high. The height of the air dryer directly affects the height of the drying cylinder, which in turn makes the path of compressed air through the molecular sieve shorter. Because the air in the straight up and down air flow channel is in contact with the molecular sieve for a relatively short time, the moisture in the air is not completely absorbed and enters the subsequent pipeline system, affecting the sensitivity and effectiveness of the vehicle's braking system; at the same time, since the resistance will increase after a large amount of oil is adsorbed in the air dryer, the air supply pressure of the braking system is insufficient, affecting the braking performance and bringing safety hazards. In addition, during backwash cleaning, due to the large amount of oil, the cleaning speed is slow, resulting in low backwash cleaning efficiency. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention proposes a new type of high-efficiency automobile air dryer under the premise of ensuring that the compressed air does not carry oil and moisture after passing through the air dryer, while ensuring the air supply pressure and improving the safety performance.

[0008] To this end, the technical solution of the present invention is: a new type of high-efficiency automobile air dryer, including a shell with a closed upper end, a bottom cover threadedly connected to the bottom of the shell, and a filter element, the bottom cover is provided with an air inlet, and the middle of the bottom cover is provided with a threaded bayonet connected to an external gas pipeline; an inner liner is provided in the shell, an inner liner cover is provided on the top of the inner liner, and a connecting plate is provided at the bottom, the downwardly extending portion in the middle of the bottom of the connecting plate is sleeved outside the threaded bayonet of the bottom cover, and a sealing ring is provided at the abutting position, the inner cavity of the inner liner constitutes a desiccant storage cavity, a spring is clamped between the inner liner cover and the shell, the inner liner cover is provided with a channel communicating with the inner liner, and the cavity between the inner liner and the shell constitutes an air channel, characterized in that:

[0009] The filter element is arranged at the upper part of the inner tank, and a filter element installation cavity is preset in the upper part of the inner tank extending from the outside to the inside, and through holes are evenly distributed on the outer wall and the upper part of the inner wall of the filter element installation cavity. A filter element is installed in the filter element installation cavity, and the top and bottom of the filter element are respectively abutted against the inner tank cover and the bottom of the filter element installation cavity, and a sealing ring is provided at the abutting part; a gas diffusion plate is arranged at the top end of the inner wall of the filter element installation cavity, and a gap for gas flow is provided between the gas diffusion plate and the inner tank cover, and through holes for gas to pass evenly are arranged on the gas diffusion plate;

[0010] A one-way bypass valve and an elastic one-way check valve are also provided on the channel of the inner tank cover. The one-way bypass valve is used to control the compressed air to enter the channel of the inner tank from the inner tank cover. The elastic one-way check valve is used to control the air flow from the inner tank cover to enter the air channel between the inner tank and the outer shell when the air dryer is backwashed and cleaned;

[0011] The middle of the connecting plate is provided with a groove extending into the inner pot, the side walls of the groove are evenly provided with air outlet holes, the inner ends of the air outlet holes are provided with filter discs, and the groove is connected with the threaded bayonet of the bottom cover; the cavity formed between the bottom surface of the connecting plate and the bottom cover, the air passage between the inner pot and the outer shell, and the air inlet on the bottom cover are connected;

[0012] A fixing rod is arranged in the center of the desiccant storage cavity and between the gas diffusion plate and the connecting plate, and a spiral piece is passed through and fixed on the fixing rod, and the outer contour of the spiral piece is adapted to the inner wall size of the inner container.

[0013] Preferably, the one-way bypass valve is arranged at the center of the top of the inner liner cover, including a cylindrical valve seat, the upper end of the cylinder is provided with an inner edge extending toward the center, and the lower end is provided with an outer flange, and the outer flange forms a mounting portion of the spring between the inner liner cover and the outer shell; a cylindrical intake valve seat is arranged in the valve seat, and through holes are evenly distributed on the cylinder wall of the intake valve seat. The upper end of the intake valve seat extends toward the center and is fixed to the inner edge of the valve seat through a U-shaped edging with an opening outward, and the lower end is provided with an inner flange bent inward and then upward, and the sliding fit of the inner cavity of the intake valve seat is provided with a sealing The gasket and the fixing plate for supporting the sealing gasket, the inner flange at the lower end of the intake valve seat constitutes a spring mounting portion between the fixing plate and the flange, the spring mounting portion is provided with a compression spring, the fixing plate is provided with a corresponding spring limiting portion, the sealing gasket abuts against the bottom of the U-shaped edge of the intake valve seat under the action of the compression spring to form a sealing structure; the inner liner cover is provided with a protrusion for limiting the one-way bypass valve, the lower end of the intake valve seat abuts against the inner side of the protrusion on the inner liner cover, and a channel is provided on the inner liner cover directly below the fixing plate. This one-way bypass valve has an ingenious structure, low manufacturing cost, and easy installation. It can be opened by airflow pressure and reset by compression spring. It does not need to be controlled by other control systems, is not easy to damage, and is easy to maintain.

[0014] Preferably, the inner side of the elastic one-way check valve plate is clamped between the valve seat and the inner liner cover near the end, the inner end of the elastic one-way check valve plate abuts against the outer side of the inner liner cover protrusion, the outer end extends outward along the inner liner cover, the bottom of the outer end is provided with a protrusion, the corresponding inner liner cover is provided with a groove, and the inner liner cover is provided with channels at the part that fits the elastic one-way check valve plate; when the elastic one-way check valve plate is in an open state, its outer end abuts against the inner wall of the shell to block the communication with the one-way bypass valve. This elastic one-way check valve plate has a simple structure and is easy to install. It can be opened by airflow pressure and reset under the action of gravity. It does not need to be controlled by other control systems, is not easy to damage, and is easy to maintain.

[0015] Preferably, the desiccant is a molecular sieve, silica gel, or cellulose particles, all of which have the function of absorbing water.

[0016] Preferably, the elastic one-way check valve plate is made of rubber material, which can ensure that the elastic one-way check valve plate has good sealing performance when the air dryer is working normally. When the air dryer is backwashed, the opening pressure of the elastic one-way check valve plate is very small, which can ensure that all the water vapor blown back is discharged outside the dryer.

[0017] Preferably, the filter element includes upper and lower end covers, a supporting frame and filter material, the upper and lower end covers are made of metal or plastic, the supporting frame is made of metal or plastic on the inner side of the filter element, and there are air inlet and outlet holes on the supporting frame. The filter material is made of synthetic fiber with oil absorption function, or non-woven fabric, or filter paper, or a combination of the three, and has the function of absorbing oil and particulate impurities in the air passing through the filter material.

[0018] Beneficial effects: The present invention can ensure the dryness and cleanliness of the braking system, thereby ensuring the braking performance of the vehicle and improving the safety of the driver.

[0019] The spiral blade guide is set in the inner tank to make the path of air passing through the desiccant longer than that of the existing air dryer, ensuring that the filtered air enters the desiccant and completely removes moisture before entering other components;

[0020] A one-way bypass valve is set on the inner tank cover. During normal operation, the compressed air first passes through the filter element and then enters the dryer for drying before entering the subsequent pipeline. However, as the filter element absorbs more and more oil and particulate impurities, the resistance of the filter element will increase accordingly. At this time, under a certain pressure, the one-way bypass valve will open, and the compressed air will enter the desiccant storage chamber through the one-way bypass valve for drying, thereby making up for the insufficient air supply pressure entering the brake system through the filter element, ensuring braking performance and eliminating safety hazards.

[0021] An elastic one-way check valve is arranged on the inner tank cover. When the car back-blows and cleans the dryer by itself, part of the airflow is back-blown out through the filter element, and the other part of the airflow opens the elastic one-way check valve through air pressure, comes out from the inner tank cover and enters the air channel between the inner tank side wall and the outer shell, and is back-blown out, thereby improving the back-blow cleaning efficiency and ensuring the cleaning effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the front view of the present invention.

[0023] Figure 2 It is a schematic diagram of installing the one-way bypass valve and the elastic one-way check valve plate on the inner tank cover of the present invention.

[0024] Figure 3 yes Figure 2 Schematic diagram of the one-way bypass valve in the open state.

[0025] Figure 4 It is a schematic diagram of the air flow path of the present invention during normal use.

[0026] Figure 5 It is a schematic diagram of the flow path of the airflow during backwash cleaning of the present invention.

[0027] As shown in the figure: 1. outer shell; 2. bottom cover; 21. air inlet; 22. threaded bayonet; 3. filter element; 4. liner; 41. through hole; 5. liner cover; 51. channel; 52. protrusion; 53. groove; 6. connecting plate; 61. air outlet; 62. filter disc; 7. spring; 8. gas diffusion plate; 81. through hole; 9. one-way bypass valve; 91. valve seat; 911. inner edge; 912. outer flange; 92. intake valve seat; 921. through hole; 922. U-shaped edging; 923. inner flange; 93. sealing gasket; 94. fixing plate; 95. compression spring; 10. elastic one-way check valve disc; 101. protrusion; 11. fixing rod; 12. spiral disc. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings, but this embodiment should not be understood as limiting the present invention.

[0029] The present invention Figures 1 to 5 As shown:

[0030] A novel high-efficiency automobile air dryer comprises a shell 1 with a closed upper end, a bottom cover 2 threadedly connected to the bottom of the shell, and a filter element 3. The bottom cover 2 is provided with an air inlet 21, and the middle of the bottom cover is provided with a threaded bayonet 22 connected to an external air pipeline; an inner liner 4 is provided in the shell, an inner liner cover 5 is provided on the top of the inner liner, and a connecting plate 6 is provided at the bottom. The downwardly extending portion in the middle of the bottom of the connecting plate is sleeved outside the threaded bayonet of the bottom cover, and a sealing ring is provided at the abutting portion. The inner cavity of the inner liner constitutes a desiccant storage cavity, and the desiccant storage cavity is filled with desiccant. A spring 7 is clamped between the inner liner cover and the shell, and a channel communicating with the inner liner is provided on the inner liner cover. The cavity between the inner liner and the shell constitutes an air channel;

[0031] The filter element 3 is arranged on the upper part of the inner tank 4. The upper part of the inner tank is extended from the outside to the inside to preset a filter element installation cavity. The outer wall of the filter element installation cavity and the upper part of the inner wall are evenly provided with through holes 41. The filter element is installed in the filter element installation cavity. The top and bottom of the filter element are respectively abutted against the inner tank cover and the bottom of the filter element installation cavity, and a sealing ring is provided at the abutting part; a gas diffusion plate 8 is mounted on the top of the inner wall of the filter element installation cavity. A gap for gas flow is provided between the gas diffusion plate and the inner tank cover 5, and through holes 81 are evenly provided on the gas diffusion plate;

[0032] A one-way bypass valve 9 and an elastic one-way check valve 10 are also provided on the channel of the inner liner cover 5. The one-way bypass valve 9 is used to control the passage of compressed air from the inner liner cover into the inner liner. The elastic one-way check valve 10 is used to control the air flow from the inner liner cover into the air passage between the inner liner and the outer shell during backwash cleaning of the air dryer.

[0033] The middle of the connecting plate 6 is provided with a groove extending into the inner pot, the side walls of the groove are evenly provided with air outlet holes 61, the inner ends of the air outlet holes are provided with filter discs 62, and the groove is connected with the threaded bayonet of the bottom cover; the cavity formed between the bottom surface of the connecting plate 6 and the bottom cover 2, the air passage between the inner pot 4 and the outer shell 1, and the air inlet 21 on the bottom cover 2 are connected;

[0034] A fixing rod 11 is provided in the center of the desiccant storage cavity between the gas diffusion plate 8 and the connecting plate 6, and a spiral piece 12 is passed through and fixed on the fixing rod. The outer contour of the spiral piece is adapted to the inner wall size of the inner container.

[0035] The one-way bypass valve 9 is arranged at the center of the top of the inner liner cover 5, including a cylindrical valve seat 91, the upper end of the cylinder is provided with an inner edge 911 extending toward the center, and the lower end is provided with an outer flange 912, the outer flange forms the mounting portion of the spring between the inner liner cover and the outer shell; a cylindrical intake valve seat 92 is arranged in the valve seat 91, and through holes 921 are evenly distributed on the cylinder wall of the intake valve seat. The upper end of the intake valve seat extends toward the center and is fixed to the inner edge of the valve seat through a U-shaped edging 922 that opens outward, and the lower end is provided with an inner flange 923 that bends inward and then upward, and a sealing gasket 93 is provided in the sliding fit of the inner cavity of the intake valve seat and a fixing plate 94 for supporting the sealing gasket, the inner flange at the lower end of the intake valve seat constitutes a spring mounting portion between the fixing plate and the inner flange, the spring mounting portion is provided with a compression spring 95, the fixing plate 94 is provided with a corresponding spring limiting portion, the sealing gasket abuts against the bottom of the U-shaped rim 922 of the intake valve seat under the action of the compression spring to form a sealing structure; the inner liner cover 5 is provided with a protrusion 52 for limiting the one-way bypass valve, the lower end of the intake valve seat 92 abuts against the inner side of the protrusion 52 on the inner liner cover 5, and the inner liner cover directly below the fixing plate 94 is provided with the channel 51. This one-way bypass valve has an ingenious structure, low manufacturing cost, and convenient installation. It can be opened by air flow pressure and reset by compression spring. It does not need to be controlled by other control systems, is not easy to damage, and is easy to maintain.

[0036] The inner side of the elastic one-way check valve plate 10 is sandwiched between the valve seat 91 and the inner liner cover 5 near the end, the inner end of the elastic one-way check valve plate abuts against the outer side of the inner liner cover protrusion 52, and the outer end extends outward along the inner liner cover, and the bottom of the outer end is provided with a protrusion 101, and the corresponding inner liner cover is provided with a groove 53 (this structure makes the one-way check valve plate and the inner liner cover fit more closely, and at the same time, the outer edge of the inner liner cover can block the compressed air flow from blowing directly to the outer end of the one-way check valve plate and the inner liner cover The junction), the inner liner cover is evenly distributed with the channels 51 at the part that fits with the elastic one-way check valve plate; when the elastic one-way check valve plate is in an open state, its outer end abuts against the inner wall of the shell, blocking the air channel between the inner liner side wall and the shell, and the connection between the one-way bypass valve. This elastic one-way check valve plate has a simple structure and is easy to install. It can be opened by air flow pressure and reset under the action of gravity. It does not need to be controlled by other control systems, is not easy to damage, and is easy to maintain.

[0037] The desiccant is a molecular sieve, silica gel, or cellulose particles, all of which have the function of absorbing water.

[0038] The elastic one-way check valve plate 10 is made of rubber material, which can ensure that the elastic one-way check valve plate has good sealing performance when the air dryer is working normally. When the air dryer is backblown, the opening pressure of the elastic one-way check valve plate is very small, which can ensure that all the water vapor blown back is discharged outside the dryer.

[0039] The filter element 3 is of prior art (not shown in the figure), including upper and lower end covers, a support frame and filter material. The upper and lower end covers are made of metal or plastic. The support frame is made of metal or plastic on the inner side of the filter element. There are air inlet and outlet holes on the support frame. The filter material adopts synthetic fiber with oil absorption function, or non-woven fabric, or filter paper, or a combination of the three, which has the function of absorbing oil and particulate impurities in the air passing through the filter material.

[0040] Working principle of the present invention:

[0041] When compressed air enters the air dryer from the air inlet of the chassis, it passes through the cavity between the bottom surface of the connecting plate and the bottom cover, and the air channel between the side wall of the inner tank and the outer shell. Under the action of compressed air, the compressed air enters the desiccant storage chamber through the filter element. When the filter element absorbs too much oil and the resistance is too large, the compressed air reaches a certain pressure, and the one-way bypass valve 9 will open (the sealing gasket and the fixing plate slide downward under the action of air pressure and compress the spring). The compressed air will enter the desiccant storage chamber through the one-way bypass valve. The two parts of the air flow are guided through the desiccant storage chamber by the spiral blade, and come out from the air outlet of the connecting plate, pass through the threaded bayonet, and then enter the car's brake system through the pipe connected to the threaded bayonet. ( Figure 4 shown)

[0042] When the air dryer needs backwash cleaning, the airflow passes through the threaded bayonet and enters the desiccant storage chamber from the air outlet of the connecting plate. It is divided at the upper part of the desiccant storage chamber. One part of the airflow passes through the filter element and enters the air channel between the inner tank side wall and the outer shell, taking away oil, impurities and some moisture. The other part of the airflow takes away moisture and enters the cavity between the top of the inner tank cover and the outer shell through the channel of the inner tank cover. Under the action of the airflow pressure, the elastic one-way check valve plate 10 abuts against the inner wall of the outer shell and is in an open state. This part of the airflow passes through the elastic one-way check valve plate and enters the air channel between the inner tank side wall and the outer shell. The two parts of the airflow pass through the cavity between the bottom surface of the connecting plate and the bottom cover and come out from the air inlet of the bottom plate. ( Figure 5 shown)

[0043] Parts not described in detail in this specification are inherent functions of technologies or components known in the art.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A novel high-efficiency automobile air dryer, comprising a shell with a closed upper end, a bottom cover threadedly connected to the bottom of the shell, and a filter element, wherein the bottom cover is provided with an air inlet, and the middle of the bottom cover is provided with a threaded bayonet connected to an external gas pipeline; an inner liner is provided in the shell, an inner liner cover is provided on the top of the inner liner, and a connecting plate is provided at the bottom, a downwardly extending portion in the middle of the bottom of the connecting plate is sleeved outside the threaded bayonet of the bottom cover, and a sealing ring is provided at the abutting portion, the inner cavity of the inner liner constitutes a desiccant storage cavity, a spring is clamped between the inner liner cover and the shell, a channel communicating with the inner liner is provided on the inner liner cover, and the cavity between the inner liner and the shell constitutes an air channel, characterized in that: The filter element is arranged at the upper part of the inner tank, and a filter element installation cavity is preset in the upper part of the inner tank extending from the outside to the inside, and through holes are evenly distributed on the outer wall and the upper part of the inner wall of the filter element installation cavity. A filter element is installed in the filter element installation cavity, and the top and bottom of the filter element are respectively abutted against the inner tank cover and the bottom of the filter element installation cavity, and a sealing ring is provided at the abutting part; a gas diffusion plate is arranged at the top end of the inner wall of the filter element installation cavity, and a gap for gas flow is provided between the gas diffusion plate and the inner tank cover, and through holes for gas to pass evenly are arranged on the gas diffusion plate; A one-way bypass valve and an elastic one-way check valve are also provided on the channel of the inner tank cover. The one-way bypass valve is used to control the compressed air to enter the channel of the inner tank from the inner tank cover. The elastic one-way check valve is used to control the air flow from the inner tank cover to enter the air channel between the inner tank and the outer shell when the air dryer is backwashed and cleaned; The middle of the connecting plate is provided with a groove extending into the inner pot, the side walls of the groove are evenly provided with air outlet holes, the inner ends of the air outlet holes are provided with filter discs, and the groove is connected with the threaded bayonet of the bottom cover; the cavity formed between the bottom surface of the connecting plate and the bottom cover, the air passage between the inner pot and the outer shell, and the air inlet on the bottom cover are connected; A fixing rod is provided in the center of the desiccant storage cavity between the gas diffusion plate and the connection plate, and a spiral sheet is fixed on the fixing rod, and the outer contour of the spiral sheet is adapted to the inner wall size of the inner container; The one-way bypass valve is arranged at the center of the top of the inner liner cover, including a cylindrical valve seat, the upper end of the cylinder is provided with an inner edge extending toward the center, and the lower end is provided with an outer flange, and the outer flange forms a mounting portion of the spring between the inner liner cover and the outer shell; a cylindrical intake valve seat is arranged in the valve seat, and through holes are evenly distributed on the cylinder wall of the intake valve seat. The upper end of the intake valve seat extends toward the center and is fixed to the inner edge of the valve seat through a U-shaped edging with an opening outward, and the lower end is provided with an inner flange bent inward and then upward, and a sealing gasket is provided for sliding cooperation in the inner cavity of the intake valve seat and a fixing plate for supporting the sealing gasket, the inner flange at the lower end of the intake valve seat constitutes a spring mounting portion between the fixing plate and the flange, the spring mounting portion is clamped with a compression spring, the fixing plate is provided with a corresponding spring limiting portion, the sealing gasket abuts against the bottom of the U-shaped edge of the intake valve seat under the action of the compression spring to form a sealing structure; the inner liner cover is provided with a protrusion for limiting the one-way bypass valve, the lower end of the intake valve seat abuts against the inner side of the protrusion on the inner liner cover, and a channel is provided on the inner liner cover directly below the fixing plate; The elastic one-way check valve plate is made of rubber; The filter element includes upper and lower end covers, a support frame and filter material. The upper and lower end covers are made of metal or plastic. The support frame is made of metal or plastic on the inner side of the filter element. There are air inlet and outlet holes on the support frame. The filter material adopts synthetic fiber with oil absorption function, or non-woven fabric, or filter paper, or a combination of the three, and has the function of absorbing oil and particulate impurities in the air passing through the filter material.

2. A novel high-efficiency automobile air dryer according to claim 1, characterized in that: The inner side of the elastic one-way check valve sheet is clamped between the valve seat and the inner liner cover near the end, the inner end of the elastic one-way check valve sheet abuts against the outer side of the protrusion of the inner liner cover, and the outer end extends outward along the inner liner cover, a protrusion is provided at the bottom of the outer end, and a groove is provided on the corresponding inner liner cover, and channels are evenly distributed at the parts of the inner liner cover that fit with the elastic one-way check valve sheet; when the elastic one-way check valve sheet is in an open state, its outer end abuts against the inner wall of the outer shell.

3. A novel high-efficiency automobile air dryer according to claim 1 or 2, characterized in that: The desiccant is molecular sieve, silica gel, or cellulose particles.

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