JPH02214554A - Method for preventing clogging of gas-solid separation cyclone - Google Patents

Abstract

PURPOSE:To effectively prevent the clogging of a gas-solid separation cyclone by providing a compressed gas injection port in the cyclone and instantaneously injecting compressed gas from the injection port once or plural times. CONSTITUTION:When a solid grain-contg. gas is introduced from an inlet 3, the solid grains are settled and separated at the lower part, and the grains are appropriately discharged from a discharge port 5. The separated gas is sent upward and discharged from a discharge port 4. The gas supply is transiently stopped after a specified time. A solenoid valve 7 is opened to instantaneously inject the compressed gas in a cylinder one or plural times at appropriate time intervals under appropriate pressure, hence the solid grains deposited in the cyclone are released and removed by the impact force of injection, the solid grains caked in the vicinity of the discharge port 5 are crushed, the crushed material is easily discharged from the discharge port, and the clogging of the cyclone is prevented.

Description

Detailed Description of the Invention (a) Object of the Invention (Field of Industrial Application) The present invention relates to a gas-solid method for separating gases containing solid particles, particularly gases containing highly adhesive and sticky solid particles. This invention relates to a method for preventing blockage of a separation cyclone.

(Prior Art) Conventionally, it has been widely practiced to treat a gas containing solid particles with a cyclone to separate the solid particles from the gas. In such gas-solid separation, especially in cyclone separation of gases containing highly adhesive and sticky solid particles, solid particles adhere to the inside of the cyclone, especially in the space above the cyclone, and the adhered particles grow over time. This will reduce the separation capacity by 1. Conventionally, as a means to prevent the adhesion and growth of such solid particles, vibration or shock is applied to the cyclone wall surface from outside the cyclone to cause the adhering material to peel off and fall, or to give fluidity to the adhering material, and the lower discharge port is A method was used to discharge it from the This method is effective as long as solid matter that has fallen off due to vibration or impact on the cyclone wall is discharged from the lower discharge port and does not block the discharge port.

However, depending on the type of solid particles, the solids that have peeled off and fallen due to the vibration or impact of the wall surface may not be discharged from the lower discharge port and may clog the cyclone discharge port. For example, in the case of pneumatic transport of low concentration urea, when a cyclone is used to separate powdered urea from the urea-containing air, the urea sticks to the vicinity of the lower discharge port of the cyclone and forms a bridge-like solidified substance, leaving the cyclone exit. However, such bridge-shaped solidified urea cannot be discharged even by vibration or impact on the wall surface from outside the cyclone.

(Problem to be solved by the invention) The present invention uses a gas-solid separation cyclone.

The object of the present invention is to provide a method for preventing clogging of the cyclone when separating a gas containing solid particles.

(b) Structure of the Invention (Means for Solving the Problem) The method for preventing blockage of a gas-solid separation cyclone of the present invention includes providing a compressed gas outlet in the gas-solid cyclone, and discharging compressed gas from the compressed gas outlet. This method is characterized by instantaneously injecting the liquid once or multiple times.

When the method of the present invention is used, solid particles adhering to the inside of the cyclone and bridge-shaped solidified objects formed by their peeling and falling objects are easily crushed by the impact force of the injected compressed gas, and the solid particles at the bottom of the cyclone are easily crushed. Since it is easily discharged from the outlet, clogging of the cyclone can be extremely effectively prevented.

In the present invention, the compressed gas outlet is provided at the lower part of the cyclone, preferably at the lower part of the cyclone, particularly near the upper part of the solid particle outlet.

Further, the gas to be ejected in the present invention is one that is chemically inert to the gas and solid particles to be separated, and specific examples thereof include air, nitrogen, carbon dioxide, and the like. In addition, various gases other than these can also be used in the separation of special gases and solids. The pressure of the compressed gas to be injected is usually 2 to 10 kl//cts2G
, preferably 3 to 61 times or more, preferably several times to 10 times at intervals of several minutes or seconds.

The method of the present invention is carried out in such a manner that compressed gas is injected into the cyclones not used for separation when a plurality of gas-solid separation cyclones are used alternately as appropriate to perform gas-solid separation continuously. This effectively prevents clogging of the cyclone and allows continuous separation of gas and solids over a long period of time.

The attached FIG. 1 is a side view showing an example of a gas-solid separation cyclone used to carry out the method for preventing blockages of the present invention. 1 in the figure is the main body of the gas-solid separation cyclone, and 2
3 is the inner cylinder, and 3 is the inlet for the solid particle-containing gas, and this inlet is attached tangentially to the cyclone lower part 1.

4 is an outlet for the separated gas, and 5 is an outlet for the separated solid particles. Is 6 a compressed gas? 7 is its electromagnetic discharge valve.

When the cyclone shown in FIG. 1 is used to introduce solid particle-containing gas from its population 3 in the connecting direction, the solid particles settle and separate downward due to gravity and centrifugal force, and are discharged from the outlet 5 as appropriate. be discharged.

Further, the separated gas rises and is discharged from the discharge port 4. After carrying out such gas-solid separation for an appropriate period of time, the introduction of the solid particle-containing gas is stopped (or if multiple cyclones are used alternately to carry out continuous separation, one separation is performed). When the compressed gas in the compressed gas tank is not in use), the electromagnetic discharge valve 7 is opened and the compressed gas is instantly injected at an appropriate pressure once or multiple times at appropriate time intervals. At the same time, the solid particles that had been peeled off and fell off due to the impact force of the jet, and the solid particles that had peeled off and fallen and the solid particles that had solidified near the discharge port 5 were also affected by the impact force of the jet. Since it is crushed by the process, it can be easily discharged from the discharge port 5.
This effectively prevents cyclone blockage.

(Example) Examples will be described below.

Example 1 Low concentration pneumatic transport system for urea (temperature: room temperature, air pressure: 0,0
5 kl/w'G, air volume: 850 Nm'/hr
, the amount of urea is 24,000 to 9. The air containing urea particles, which is continuously sent from
The urea was received alternately at minute intervals and processed continuously, and the urea separated by each cyclone was allowed to fall into each urea storage tank at the bottom.

In this case, the cyclone after stopping receiving urea-containing air,
When compressed air of 97 cm G was injected instantaneously 2 to 3 times at 3' intervals at 5 minute intervals (the amount of air injected at one time was 81),
Can effectively prevent cyclone blockage.

Even during long-term continuous operation in which the two cyclones were used alternately, no cyclone freezing occurred.

Example 2 When the ethylene/zorobire/copolymer powder crushed in a crusher is transported to a drying process using heated nitrogen gas and dry transport with low concentration of nitrogen (solid/gas ratio = 0.2). The method of the present invention was applied to a cyclone that separates copolymer from nitrogen containing ethylene-propylene copolymer powder.

That is, in the dry transport of the ethylene-propylene copolymer powder at a low concentration of nitrogen, a gas heated to a temperature of about 60 to 150° C. is used as the nitrogen gas.

And when the reception of copolymer into a cyclone is temporarily stopped, such as during a product grade changeover, for example, the stopped cyclone has conventionally been unavoidable to become clogged.

However, when the reception of the ethylene/zorobire/copolymer powder was stopped, compressed nitrogen gas of 3 to 9/an2G was instantaneously injected into the cyclone immediately after the reception was stopped three times at 1-minute intervals according to the present invention. However, it is possible to completely prevent the cyclone from freezing.

(c) Effects of the Invention By using the method of the present invention, clogging of gas-solid separation cyclones can be effectively prevented.

[Brief explanation of the drawing]

FIG. 1 is a side view of a gas-solid separation cyclone used in carrying out the present invention, and each group in the figure shows the following, respectively. 1...Cyclone main body Double cyclone inner cylinder 3...Inlet for gas containing solid particles 4...Outlet for separated gas 5...Outlet for separated solid particles 6...Compressed gas membrane... solenoid discharge valve

Claims (3)

[Claims] (1) A method for preventing blockage of a gas-solid separation cyclone, which comprises providing a compressed gas outlet in the gas-solid separation cyclone and instantaneously injecting compressed gas from the compressed gas outlet once or multiple times. (2) The method according to claim 1, wherein the compressed gas outlet is provided above the solid particle outlet in the lower part of the cyclone. (3) The method according to claim 1 or 2, wherein gas-solid separation is performed by alternately using a plurality of gas-solid separation cyclones, and compressed gas is injected into the cyclones when they are not being used for separation.